bluuebunny/crossref_metadata_2025 huggingface dataset:
Polarization properties of single and ensembles of InAs/InP quantum rod nanowires emitting in the telecom wavelengths
Authors: Anufriev R. , Chauvin N. , Khmissi H. , Naji K. , Barakat J.-B. , Penuelas J. , Patriarche G. , Gendry M. , Bru-Chevallier C.
Published: May 2013

The absorption and emission polarization properties of InAs quantum rods embedded in InP nanowires (NWs) are investigated by mean of (micro-)photoluminescence spectroscopy. It is shown that the degree of linear polarization of emission (0.94) and absorption (0.5) of a single NW can be explained by the photonic nature of the NW structure. Knowing these parameters, optical properties of single NWs and ordered ensembles of these NWs can be correlated one to another via proposed model, so that polarization properties of NWs can be studied using ordered ensembles on as-grown samples. As an example, the polarization anisotropy is investigated as a function of the excitation wavelength on a NW ensemble and found to be in agreement with theoretical prediction.
First operation with the JET International Thermonuclear Experimental Reactor-like wall
Authors: Neu R. , Arnoux G. , Beurskens M. , Bobkov V. , Brezinsek S. , Bucalossi J. , Calabro G. , Challis C. , Coenen J. W. , de la Luna E. , de Vries P. C. , Dux R. , Frassinetti L. , Giroud C. , Groth M. , Hobirk J. , Joffrin E. , Lang P. , Lehnen M. , Lerche E. , Loarer T. , Lomas P. , Maddison G. , Maggi C. , Matthews G. , Marsen S. , Mayoral M.-L. , Meigs A. , Mertens Ph. , Nunes I. , Philipps V. , Pütterich T. , Rimini F. , Sertoli M. , Sieglin B. , Sips A. C. C. , van Eester D. , van Rooij G. ,   JET-EFDA Contributors
Published: May 2013

To consolidate International Thermonuclear Experimental Reactor (ITER) design choices and prepare for its operation, Joint European Torus (JET) has implemented ITER's plasma facing materials, namely, Be for the main wall and W in the divertor. In addition, protection systems, diagnostics, and the vertical stability control were upgraded and the heating capability of the neutral beams was increased to over 30 MW. First results confirm the expected benefits and the limitations of all metal plasma facing components (PFCs) but also yield understanding of operational issues directly relating to ITER. H-retention is lower by at least a factor of 10 in all operational scenarios compared to that with C PFCs. The lower C content (≈ factor 10) has led to much lower radiation during the plasma burn-through phase eliminating breakdown failures. Similarly, the intrinsic radiation observed during disruptions is very low, leading to high power loads and to a slow current quench. Massive gas injection using a D2/Ar mixture restores levels of radiation and vessel forces similar to those of mitigated disruptions with the C wall. Dedicated L-H transition experiments indicate a 30% power threshold reduction, a distinct minimum density, and a pronounced shape dependence. The L-mode density limit was found to be up to 30% higher than for C allowing stable detached divertor operation over a larger density range. Stable H-modes as well as the hybrid scenario could be re-established only when using gas puff levels of a few 1021 es−1. On average, the confinement is lower with the new PFCs, but nevertheless, H factors up to 1 (H-Mode) and 1.3 (at βN≈3, hybrids) have been achieved with W concentrations well below the maximum acceptable level.
Density functional theory study of the organic functionalization of hydrogenated silicene
Authors: Rubio-Pereda Pamela , Takeuchi Noboru
Published: May 2013

Silicene, the silicon analogous of graphene, is a newly synthesized two-dimensional nanomaterial, with unique features and promising potential applications. In this paper we present density functional theory calculations of the organic functionalization of hydrogenated silicene with acetylene, ethylene, and styrene. The results are compared with previous works of the adsorption on H-Si[111]. For styrene, binding energies for the intermediate and final states as well as the energy barrier for hydrogen abstraction are rather similar for the two systems. On the other hand, results for acetylene and ethylene are surprisingly different in H-silicene: the abstraction barrier is much smaller in H-silicene than in H-Si[111]. These differences can be understood by the different electrostatic potentials due to the presence of the H atoms at the bottom of the silicene bilayer that allows the delocalization of the spin density at the reaction intermediate state.
Comment on “Unified explanation of the anomalous dynamic properties of highly asymmetric polymer blends” [J. Chem. Phys. 138, 054903 (2013)]
Authors: Colmenero J.
Published: May 2013

In a recent paper by Ngai and Capaccioli [“Unified explanation of the anomalous dynamic properties of highly asymmetric polymer blends,” J. Chem. Phys. 138, 054903 (2013)10.1063/1.4789585] the authors claimed that the so-called coupling model (CM) provides a unified explanation of all dynamical anomalies that have been reported for dynamically asymmetric blends over last ten years. Approximately half of the paper is devoted to chain-dynamic properties involving un-entangled polymers. According to the authors, the application of the CM to these results is based on the existence of a crossover at a time tc ≈ 1–2 ns of the magnitudes describing chain-dynamics. Ngai and Capaccioli claimed that the existence of such a crossover is supported by the neutron scattering and MD-simulation results, corresponding to the blend poly(methyl methacrylate)/poly(ethylene oxide), by Niedzwiedz et al. [Phys. Rev. Lett. 98, 168301 (2007)10.1103/PhysRevLett.98.168301] and Brodeck et al. [Macromolecules 43, 3036 (2010)10.1021/ma902820a], respectively. Being one of the authors of these two papers, I will demonstrate here that there is no evidence supporting such a crossover in the data reported in these papers.
Characterization of a novel, short pulse laser-driven neutron source
Authors: Jung D. , Falk K. , Guler N. , Deppert O. , Devlin M. , Favalli A. , Fernandez J. C. , Gautier D. C. , Geissel M. , Haight R. , Hamilton C. E. , Hegelich B. M. , Johnson R. P. , Merrill F. , Schaumann G. , Schoenberg K. , Schollmeier M. , Shimada T. , Taddeucci T. , Tybo J. L. , Wender S. A. , Wilde C. H. , Wurden G. A. , Roth M.
Published: May 2013

We present a full characterization of a short pulse laser-driven neutron source. Neutrons are produced by nuclear reactions of laser-driven ions deposited in a secondary target. The emission of neutrons is a superposition of an isotropic component into 4π and a forward directed, jet-like contribution, with energies ranging up to 80 MeV. A maximum flux of 4.4 × 109 neutrons/sr has been observed and used for fast neutron radiography. On-shot characterization of the ion driver and neutron beam has been done with a variety of different diagnostics, including particle detectors, nuclear reaction, and time-of-flight methods. The results are of great value for future optimization of this novel technique and implementation in advanced applications.
Structural and vibrational stability of M and Z phases of silicon and germanium from first principles
Authors: Bautista-Hernández A. , Rangel T. , Romero A. H. , Rignanese G.-M. , Salazar-Villanueva M. , Chigo-Anota E.
Published: May 2013

First-principles calculations were performed to investigate the structural feasibility of M and Z phases (novel monoclinic and orthorhombic structures recently reported for carbon) for silicon and germanium. The lattice parameters, bulk modulus, vibrational properties, and elastic constants are calculated using the local density approximation to describe the exchange-correlation energy, while the optical properties are calculated by using Many-Body Perturbation Theory in the G0W0 approximation. Our results indicate that silicon and germanium with the proposed crystal symmetries are elastically and vibrationally stable and are small band-gap semiconductors. We discuss the possible synthesis of such materials.
Cross-plane thermoelectric transport in p-type La0.67Sr0.33MnO3/LaMnO3 oxide metal/semiconductor superlattices
Authors: Jha Pankaj , Sands Timothy D. , Jackson Philip , Bomberger Cory , Favaloro Tela , Hodson Stephen , Zide Joshua , Xu Xianfan , Shakouri Ali
Published: May 2013

The cross-plane thermoelectric transport properties of La0.67Sr0.33MnO3 (LSMO)/LaMnO3 (LMO) oxide metal/semiconductor superlattices were investigated. The LSMO and LMO thin-film depositions were performed using pulsed laser deposition to achieve low resistivity constituent materials for LSMO/LMO superlattice heterostructures on (100)-strontium titanate substrates. X-ray diffraction and high-resolution reciprocal space mapping indicate that the superlattices are epitaxial and pseudomorphic. Cross-plane devices were fabricated by etching cylindrical pillar structures in superlattices using inductively, this coupled-plasma reactive-ion etching. The cross-plane electrical conductivity data for LSMO/LMO superlattices reveal a lowering of the effective barrier height to 223 meV as well as an increase in cross-plane conductivity by an order of magnitude compared to high resistivity superlattices. These results suggest that controlling the oxygen deficiency in the constituent materials enables modification of the effective barrier height and increases the cross-plane conductivity in oxide superlattices. The cross-plane LSMO/LMO superlattices showed a giant Seebeck coefficient of 2560 μV/K at 300 K that increases to 16 640 μV/K at 360 K. The giant increase in the Seebeck coefficient with temperature may include a collective contribution from the interplay of charge, spin current, and phonon drag. The low resistance oxide superlattices exhibited a room temperature cross-plane thermal conductivity of 0.92 W/m K, this indicating that the suppression of thermal conductivities due to the interfaces is preserved in both low and high resistivity superlattices. The high Seebeck coefficient, the order of magnitude improvement in cross-plane conductivity, and the low thermal conductivity in LSMO/LMO superlattices resulted in a two order of magnitude increase in cross-plane power factor and thermoelectric figure of merit (ZT), compared to the properties of superlattices with higher resistivity that were reported previously. The temperature dependence of the cross-plane power factor in low resistance superlattices suggests a direction for further investigations of the potential LSMO/LMO oxide superlattices for thermoelectric devices.
Fabrication and characterization of a room-temperature ZnO polariton laser
Authors: Li Feng , Orosz L. , Kamoun O. , Bouchoule S. , Brimont C. , Disseix P. , Guillet T. , Lafosse X. , Leroux M. , Leymarie J. , Malpuech G. , Mexis M. , Mihailovic M. , Patriarche G. , Réveret F. , Solnyshkov D. , Zuniga-Perez J.
Published: May 2013

A ZnO planar optical microcavity displaying room-temperature polariton lasing over a wide range of cavity-exciton detunings has been fabricated. The cavity combines optimum crystalline quality, given by a ZnO single-crystal substrate, and optimum photonic quality, obtained by the use of two dielectric SiO2/HfO2 Bragg mirrors. A maximum cavity quality factor of about 4000 has been measured. Typically, the polariton lasing transition is accompanied by an increase of the output intensity by more than two orders of magnitude, a reduction of the emission linewidth and a relatively small blueshift of the lower polariton branch (less than 5% of the Rabi splitting).
Avalanche transition with super-bandwidth magnetic field response in (La0.73Bi0.27)0.67Ca0.33MnO3
Authors: Xia Zhengcai , Chen Borong , Wu Yuying , Ouyang Zhongwen , Wu Yue , Xiao Lixia , Huang Junwei , Shi Lirang , Shang Cui , Jin Zhao , Li Liang
Published: May 2013

The magnetic and electrical behaviors of an optimizing doping (La0.73Bi0.27)0.67Ca0.33MnO3 were investigated. An avalanche transition with a super-bandwidth of magnetic field response, in which the magnetic field sweep rate ranging from 10 Oe/s to 4886.8 T/s, was observed in the manganite. The insensitivity of the critical field of the avalanche transition to the magnetic field weep rates could not be described well within the framework of martensitic transition scenario. Based on the hybridization between the Bi3+-6s lone pair electrons and O2–2p electrons, we assume that the observed super-bandwidth avalanche transition is an intrinsic behavior resulting from the s-p hybridization. The robust transition makes the material extremely attractive for potential applications in super-bandwidth magnetic field response sensor. The simple structure of the current system also provides an ideal platform for understanding the physics underlying the avalanche transition.
Coupling of InAs/InP quantum dots to the plasmon resonance of In nanoparticles grown by metal-organic vapor phase epitaxy
Authors: Yuan Jiayue , Jin C. Y. , Skacel Matthias , Urbańczyk Adam , Xia Tian , van Veldhoven P. J. , Nötzel Richard
Published: May 2013

We report strongly modified optical emission of InAs/InP quantum dots (QDs) coupled to the surface plasmon resonance (SPR) of In nanoparticles grown by metal-organic vapor phase epitaxy. With increasing In deposition time, the In nanoparticle size increases and the SPR redshifts significantly. When overlapping with the SPR, the excited state photoluminescence of the QDs is strongly enhanced due to QD-SPR coupling while the ground state photoluminescence is quenched due to non-radiative energy transfer. This is underpinned by the wavelength dependence of the spontaneous emission decay time which shows an opposite trend compared to that of bare QDs.
Performance limits of transition metal dichalcogenide (MX2) nanotube surround gate ballistic field effect transistors
Authors: Sengupta Amretashis , Mahapatra Santanu
Published: May 2013

We theoretically analyze the performance of transition metal dichalcogenide (MX2) single wall nanotube (SWNT) surround gate MOSFET, in the 10 nm technology node. We consider semiconducting armchair (n, n) SWNT of MoS2, MoSe2, WS2, and WSe2 for our study. The material properties of the nanotubes are evaluated from the density functional theory, and the ballistic device characteristics are obtained by self-consistently solving the Poisson-Schrödinger equation under the non-equilibrium Green's function formalism. Simulated ON currents are in the range of 61–76 μA for 4.5 nm diameter MX2 tubes, with peak transconductance ∼175–218 μS and ON/OFF ratio ∼0.6 × 105–0.8 × 105. The subthreshold slope is ∼62.22 mV/decade and a nominal drain induced barrier lowering of ∼12–15 mV/V is observed for the devices. The tungsten dichalcogenide nanotubes offer superior device output characteristics compared to the molybdenum dichalcogenide nanotubes, with WSe2 showing the best performance. Studying SWNT diameters of 2.5–5 nm, it is found that increase in diameter provides smaller carrier effective mass and 4%–6% higher ON currents. Using mean free path calculation to project the quasi-ballistic currents, 62%–75% reduction from ballistic values in drain current in long channel lengths of 100, 200 nm is observed.
Broadband saturable absorption and optical limiting in graphene-polymer composites
Authors: Husaini S. , Slagle J. E. , Murray J. M. , Guha S. , Gonzalez L. P. , Bedford R. G.
Published: May 2013

Nonlinear optical properties of a graphene-polyvinyl alcohol composite are studied using an irradiance-scan setup. The measurements are carried out at 785 nm and 1064 nm in the nanosecond and picoseconds temporal regimes, respectively. It is shown that the output fluence readily clamps with increasing input and graphene concentration due to nonlinear absorption and scattering. Furthermore, the nonlinear transmission demonstrates weak saturable absorption followed by strong optical limiting. The nonlinear coefficients βeff and Isat calculated via numerical fitting show that βeff depends on the graphene content and increases significantly in nanosecond regime due to high degree of thermally induced nonlinear scattering.
Comparative study of magnetic and magnetotransport properties of Sm0.55Sr0.45MnO3 thin films grown on different substrates
Authors: Srivastava Manoj K. , Singh Sandeep , Siwach P. K. , Kaur Amarjeet , Awana V. P. S. , Maurya K. K. , Singh H. K.
Published: May 2013

Highly oriented polycrystalline Sm0.55Sr0.45MnO3 thin films (thickness ∼100 nm) deposited on LaAlO3 (LAO, (001)), SrTiO3 (STO, (001)) and (La0.18Sr0.82) (Al0.59Ta0.41)O3 (LSAT, (001)) single crystal substrates by ultrasonic nebulized spray pyrolysis have been studied. The out of plane lattice parameter (OPLP) of the film on LAO is slightly larger than that of the corresponding bulk. In contrast, the OPLP of the films on STO and LSAT are slightly smaller than the corresponding bulk value. This suggests that the film on LAO is under compressive strain while LSAT and STO are under tensile strain. The films on LAO and LSAT show simultaneous paramagnetic-ferromagnetic (PM–FM) and insulator-metal transition (IMT) temperature at TC/TIM ∼ 165 K and 130 K, respectively. The PM–FM and IM transition occur at TC ∼ 120 K and TIM ∼ 105 K, respectively in the film on STO substrate. At T < TC, the zero field cooled–field cooled (ZFC–FC) magnetization of all the films shows strong bifurcation. This suggests the presence of a metamagnetic state akin to cluster glass formed due to coexisting FM and antiferromagnetic–charge order (AFM–CO) clusters. All the films show colossal magnetoresistance but its temperature and magnetic field dependence are drastically different. The films on LAO and STO show peak CMR around TC/TIM, while the film on LSAT shows MR > 99 % over a very wide temperature range of ∼40 K centred on TC/TIM. In the lower temperature region the magnetic field dependent isothermal resistivity also shows signature of metamagnetic transitions. The observed results have been explained in terms of the variation of the relative fractions of the coexisting FM and AFM–CO phases as a function of the substrate induced strain and oxygen vacancy induced quenched disorder.
Effect of proton irradiation on AlGaN/GaN micro-Hall sensors
Authors: Abderrahmane A. , Koide S. , Okada H. , Takahashi H. , Sato S. , Ohshima T. , Sandhu A.
Published: May 2013

The magnetoelectric properties of AlGaN/GaN micro-Hall effect sensors were studied after 380 keV proton irradiation. After irradiation the current-voltage measurements, stability of the magnetic sensitivity of the sensors, and the sheet electron density were degraded with a dramatic decrease of the electron mobility at high temperatures. Raman spectroscopy showed a degradation in the crystalline quality of GaN crystal, but there was no change in the strain.
Note: Operation of gamma-ray microcalorimeters at elevated count rates using filters with constraints
Authors: Alpert B. K. , Horansky R. D. , Bennett D. A. , Doriese W. B. , Fowler J. W. , Hoover A. S. , Rabin M. W. , Ullom J. N.
Published: May 2013

Microcalorimeter sensors operated near 0.1 K can measure the energy of individual x- and gamma-ray photons with significantly more precision than conventional semiconductor technologies. Both microcalorimeter arrays and higher per pixel count rates are desirable to increase the total throughput of spectrometers based on these devices. The millisecond recovery time of gamma-ray microcalorimeters and the resulting pulse pileup are significant obstacles to high per pixel count rates. Here, we demonstrate operation of a microcalorimeter detector at elevated count rates by use of convolution filters designed to be orthogonal to the exponential tail of a preceding pulse. These filters allow operation at 50% higher count rates than conventional filters while largely preserving sensor energy resolution.
Insulated multinozzle system for electrohydrodynamic atomization in the simple-jet mode
Authors: Agostinho L. L. F. , Yurteri C. U. , Wartena J. , Brouwer S. P. , Fuchs E. C. , Marijnissen J. C. M.
Published: May 2013

In this study, a multinozzle electrohydrodynamic atomization device was designed and studied for electrosprays in the simple-jet mode. Results have shown that the proposed device produces droplets with similar diameter in all nozzles, that the electric field creates a unique dispersion of the charged droplets and that it can operate under relatively high humidity conditions.
Spin torque transistor revisited
Authors: Chiba Takahiro , Bauer Gerrit E. W. , Takahashi Saburo
Published: May 2013

We theoretically study the operation of a 4-terminal device consisting of two lateral thin-film spin valves that are coupled by a magnetic insulator such as yttrium iron garnet via the spin transfer torque. By magnetoelectronic circuit theory we calculate the current voltage characteristics and find negative differential resistance and differential gain in a large region of parameter space. We demonstrate that functionality is preserved when the control spin valve is replaced by a normal metal film with a large spin Hall angle.
High-power low-divergence tapered quantum cascade lasers with plasmonic collimators
Authors: Blanchard Romain , Mansuripur Tobias S. , Gökden Burc , Yu Nanfang , Kats Mikhail , Genevet Patrice , Fujita Kazuue , Edamura Tadataka , Yamanishi Masamichi , Capasso Federico
Published: May 2013

We demonstrate a tapered quantum cascade laser with sloped side-walls emitting a high-brightness single-lobe beam at 8.1 μm with a peak power of 4 W at room temperature. Using a combination of high and low reflectivity facet coatings, the power output is increased to 6.2 W while a high beam quality is maintained. Plasmonic collimators are fabricated on the facet of the uncoated lasers without compromising power output, demonstrating the viability of this beam-shaping strategy for high-power lasers. The collimated lasers emit a beam with a more circular cross-section, which is more amenable to high-efficiency coupling into mid-infrared optical fibers.
How reliable are Hanle measurements in metals in a three-terminal geometry?
Authors: Txoperena Oihana , Gobbi Marco , Bedoya-Pinto Amilcar , Golmar Federico , Sun Xiangnan , Hueso Luis E. , Casanova Fèlix
Published: May 2013

We test the validity of Hanle measurements in three-terminal devices by using aluminum (Al) and gold (Au). The obtained Hanle and inverted Hanle-like curves show an anomalous behavior. First, we measure Hanle signals 8 orders of magnitude larger than those predicted by standard theory. Second, the temperature and voltage dependences of the signal do not match with the tunneling spin polarization of the ferromagnetic contact. Finally, the spin relaxation times obtained with this method are independent of the choice of the metallic channel. These results are not compatible with spin accumulation in the metal. Furthermore, a scaling of the Hanle signal with the interface resistance of the devices suggests that the measured signal is originated in the tunnel junction.
Floating electrode electrowetting on hydrophobic dielectric with an SiO2 layer
Authors: Khodayari Mehdi , Hahne Benjamin , Crane Nathan B. , Volinsky Alex A.
Published: May 2013

Floating electrode electrowetting is caused by dc voltage applied to a liquid droplet on the Cytop surface, without electrical connection to the substrate. The effect is caused by the charge separation in the floating electrode. A highly resistive thermally grown SiO2 layer underneath the Cytop enables the droplet to hold charges without leakage, which is the key contribution. Electrowetting with a SiO2 layer shows a memory effect, where the wetting angle stays the same after the auxiliary electrode is removed from the droplet in both conventional and floating electrode electrowetting. Floating electrode electrowetting provides an alternative configuration for developing advanced electrowetting-based devices.
High quality factor nonpolar GaN photonic crystal nanocavities
Authors: Wu Tzeng-Tsong , Lo Sheng-Yun , Huang Huei-Min , Tsao Che-Wei , Lu Tien-Chang , Wang Shing-Chung
Published: May 2013

High quality factor a-plane nonpolar GaN two-dimensional photonic crystal (PC) nanocavities on r-plane sapphire substrates have been demonstrated. Nonpolar GaN PC nanocavities on a thin membrane structure were realized by using e-beam lithography to define the PC patterns and focused-ion beam milling to fabricate the suspended thin membrane. A dominant resonant mode at 388 nm with a high quality factor of approximately 4300 has been demonstrated at 77 K by the micro-photoluminescence system. Moreover, the degree of polarization of the emission from the non-polar GaN PC nanocavity was measured to be 64% along the m crystalline direction.
Dominant deuteron acceleration with a high-intensity laser for isotope production and neutron generation
Authors: Maksimchuk A. , Raymond A. , Yu F. , Petrov G. M. , Dollar F. , Willingale L. , Zulick C. , Davis J. , Krushelnick K.
Published: May 2013

Experiments on the interaction of an ultra-short pulse laser with heavy-water, ice-covered copper targets, at an intensity of 2×1019 W/cm2, were performed demonstrating the generation of a “pure” deuteron beam with a divergence of 20°, maximum energy of 8 MeV, and a total of 3×1011 deuterons with energy above 1 MeV—equivalent to a conversion efficiency of 1.5% ± 0.2%. Subsequent experiments on irradiation of a B10 sample with deuterons and neutron generation from d-d reactions in a pitcher-catcher geometry, resulted in the production of ∼106 atoms of the positron emitter C11 and a neutron flux of (4±1)×105 neutrons/sterad, respectively.
Clinician and patient perspectives of a new model of triage in a community rehabilitation program that reduced waiting time: a qualitative analysis
Authors: Harding Katherine E. , Taylor Nicholas F. , Bowers Birgitte , Stafford Maree , Leggat Sandra G.
Published: May 2013

Background
A trial of a new model of triage (Specific and Timely Appointments for Triage: STAT) at a community rehabilitation program (CRP) reduced the mean time to first appointment from 17.5 to 10.0 days. However, quantitative findings reveal little about the impact of the system on those who used it. We aimed to explore the experiences of patients and clinicians following the introduction of STAT.

Method
Qualitative study within a convergent mixed-methods design applied to a controlled before and after trial at a CRP. Semi-structured interviews (n = 32) were conducted with clinicians who experienced the change to STAT, patients admitted to the CRP using STAT and patients who attended rehabilitation via a triaged wait list at another site.

Results
Clinicians reported shorter waiting times, more flexibility and increased efficiency with STAT, and noted the importance of effective change management. Patients reported a more efficient and consistent pathway to rehabilitation with STAT. Waiting had negative consequences for some patients at the triaged wait list site.

Conclusions
The qualitative data provide context to the quantitative results by showing that the changes that reduced waiting times were also well accepted and perceived to be beneficial by both patients and clinicians.

What is known about the topic?
Triage systems are widely used but can contribute to inefficiencies in health care. An alternative method of triage (STAT) using early allocation to face-to-face appointments has been shown to reduce waiting times in a community rehabilitation service.

What does this paper add?
This paper explains and adds important context to the quantitative findings by exploring the perceptions of the staff and patients who experienced both the existing and alternative models of triage.

What are the implications for practitioners?
The STAT model was well received by staff and patients, suggesting that this simple intervention was a feasible and effective method of reducing waiting times for community rehabilitation, and may be applicable to other services that share similar features.
Concurrent sexual partnerships among young adults in Cape Town, South Africa: how is concurrency changing?
Authors: Maughan-Brown Brendan
Published: May 2013

Background
The current debate about the role of concurrent sexual partnerships in the spread of HIV is influenced by limited or weak empirical data on concurrency. There is still uncertainty about the most basic statistics and little is known about how concurrency is changing. Methods: Longitudinal data (n = 2958) with repeated concurrency measures were employed to examine the prevalence of individual concurrency (someone has other partners during their most recent sexual partnership) and perceived partner concurrency (someone perceives his or her partner to have other partners) by population group and gender in 2005 and 2009. Individual fixed-effects logit regression models were created to examine factors associated with changes in individual concurrency among Black men and women. Results: The prevalence of individual concurrency increased among Black men who reported having had sex (from 33% in 2005 to 39% in 2009), remained constant among Black women (14%), decreased among Coloured (mixed-race) men (from 16% to 8%) and remained low among Coloured women (2% in 2005 and 1% in 2009). Overall, a small decrease in perceived partner concurrency was observed. Changes in individual concurrency were positively associated with changes in perceived partner concurrency among men and women. Among Black women, decreases in household income and finding employment increased the odds of reporting a positive change in individual concurrency. Conclusions: Race and gender differences in concurrency should be taken into account in future research and HIV prevention initiatives. High and increasing levels of concurrency within most recent partnerships among Black men highlight this group as a potential focus for such efforts.
Daily movement responses by African savanna ungulates as an indicator of seasonal and annual food stress
Authors: Owen-Smith Norman
Published: May 2013

Context Daily movement responses could indicate food deficiencies threatening population persistence before consequences for population performance become manifested. Animals should respond to food deficiencies by spending less time in foraging areas and hence by moving more frequently between such areas between one day and the next. Aim To establish whether the day-to-day movements of a locally threatened ruminant (sable antelope) reflected anticipated seasonal and annual variation in food stress, in comparison with a non-ruminant grazer that was thriving despite being dependent on basically similar food resources (zebra). Methods Diel (24 h) displacement distances that were derived from geographic positioning systems (GPS) telemetry were used to make the following comparisons: (1) between benign and adverse seasons, (2) among years differing in rainfall, (3) between the remnant sable herd and herds of zebra in the same region, and (4) between this sable antelope herd and sable herds in a wetter region where food should be more abundant. Key results Sable herds generally moved further from day to day in the late dry season than in the wet or early dry season, especially in the years with less rainfall, and greater movement was shown by the sable herd in the drier region than for herds in the wetter region. Zebra herds generally moved further from day to day than the sable herd occupying the same region, but showed less change in their diel displacement distances during the late dry season. Key conclusions Findings were consistent with the expected effects of seasonal, annual and regional differences in food availability on the daily movement distances of sable antelope herds. Implications Daily movement distances could serve as an indicator of when and where food deficiencies are experienced by sable antelope and perhaps other large ungulates.
Notch2 regulates BMP signaling and epithelial morphogenesis in the ciliary body of the mouse eye
Authors: Zhou Yi , Tanzie Christopher , Yan Zhipeng , Chen Shuyi , Duncan Michael , Gaudenz Karin , Li Hua , Seidel Christopher , Lewis Brandy , Moran Andrea , Libby Richard T. , Kiernan Amy E. , Xie Ting
Published: May 2013

The ciliary body (CB) of the mammalian eye is responsible for secreting aqueous humor to maintain intraocular pressure, which is elevated in the eyes of glaucoma patients. It contains a folded two-layered epithelial structure comprising the nonpigmented inner ciliary epithelium (ICE), the pigmented outer ciliary epithelium (OCE), and the underlying stroma. Although the CB has an important function in the eye, its morphogenesis remains poorly studied. In this study, we show that conditional inactivation of the Jagged 1 (Jag1)-Notch2 signaling pathway in the developing CB abolishes its morphogenesis. Notch2 is expressed in the OCE of the CB, whereas Jag1 is expressed in the ICE. Conditional inactivation of
Jag1
in the ICE or
Notch2
in the OCE disrupts CB morphogenesis, but neither affects the specification of the CB region. Notch2 signaling in the OCE is required for promoting cell proliferation and maintaining bone morphogenetic protein (BMP) signaling, both of which have been suggested to be important for CB morphogenesis. Although Notch and BMP signaling pathways are known to cross-talk via the interaction between their downstream transcriptional factors, this study suggests that Notch2 maintains BMP signaling in the OCE possibly by repressing expression of secreted BMP inhibitors. Based on our findings, we propose that Jag1-Notch2 signaling controls CB morphogenesis at least in part by regulating cell proliferation and BMP signaling.
Experimental evidence that evolutionarily diverse assemblages result in higher productivity
Authors: Cadotte Marc W.
Published: May 2013

There now is ample experimental evidence that speciose assemblages are more productive and provide a greater amount of ecosystem services than depauperate ones. However, these experiments often conclude that there is a higher probability of including complementary species combinations in assemblages with more species and lack a priori prediction about which species combinations maximize function. Here, I report the results of an experiment manipulating the evolutionary relatedness of constituent plant species across a richness gradient. I show that assemblages with distantly related species contributed most to the higher biomass production in multispecies assemblages, through species complementarity. Species produced more biomass than predicted from their monocultures when they were in plots with distantly related species and produced the amount of biomass predicted from monoculture when sown with close relatives. This finding suggests that in the absence of any other information, combining distantly related species in restored or managed landscapes may serve to maximize biomass production and carbon sequestration, thus merging calls to conserve evolutionary history and maximize ecosystem function.
Information Structure: The final hurdle?
Authors: Verheijen Lieke , Los Bettelou , de Haan Pieter
Published: May 2013

Although texts produced by (very) advanced Dutch learners of English as a foreign language (EFL) may be perfectly grammatical, they often feel distinctly non-native. Dutch, as a verb-second language, makes separate positions available for discourse linking and aboutness-topics. Although the English sentences of these advanced learners conform to the subject-verb-object order of English, the pre-subject adverbial position in English is made to perform the information-structural function of the verb-second discourse-linking position, producing texts that are perceived as non-native, without being ungrammatical. A side-effect of this L1 interference is the underuse of special focusing constructions in English, like the stressed-focus it-cleft. This paper investigates the progress of Dutch writers towards a more native-like use of the pre-subject position and the it-cleft in a longitudinal corpus of 137 writings of Dutch university students of English. We conclude that information-structural differences present the final hurdle for advanced Dutch EFL writers.
An investigation into the writing construct(s) measured in Pearson Test of English Academic
Authors: Zheng Ying , Mohammadi Shaida
Published: May 2013

Pearson Test of English Academic (PTE Academic) has six item types that assess academic writing either independently or integratively. This research focuses on evaluating the construct validity and effectiveness of the six writing item types. Exploratory Factor Analysis was performed to examine the underlying writing constructs as measured by the six item types. Item scores for different writing skills were subjected to Rasch IRT analysis. The difficulty of the item types was estimated and the effectiveness of each item type was evaluated by calculating the information function of each one. The results identified two writing constructs: an Analytical/Local Writing construct and a Synthetic/Global Writing construct. The study has implications for test developers on the use of multiple item types and their effectiveness, and for test users on how they can improve their writing skills.
Holding gestures across turns
Authors: Sikveland Rein Ove , Ogden Richard
Published: May 2013

It is widely supposed that speakers only gesture while speaking. In this paper, we consider how participants in Norwegian conversation use gestures held beyond the end of a turn-at-talk as a way to handle issues of shared understanding. Analysis combining the techniques of conversation analysis, linguistic, phonetic and visual analysis, demonstrates how participants use and orient to such held gestures as displays of occasions where participants do not (yet) have a shared understanding. The paper discusses how understanding is explicitly brought forward in a sequence of turns, and how shared understandings are reached and marked through a combination of spoken and gestural elements. The paper emphasizes the temporal progressivity of talk, the delicate timing of speech and gesture relative to one another, and the participants’ collaboration in successfully achieving and maintaining intersubjectivity.
How language evolved from manual gestures
Authors: Corballis Michael C.
Published: May 2013

Several lines of evidence suggest that human language originated in manual gestures, not vocal calls. These are the ability of nonhuman primates to use manual action flexibly and intentionally, the nature of the primate mirror system and its homology with the language circuits in the human brain, the relative success in teaching apes to communicate manually rather than vocally, the ready invention of sophisticated signed languages by the deaf, the critical role of pointing in the way young children learn language, and the correlation between handedness and cerebral asymmetry for language. A gradual switch from manual to facial and vocal expression may have occurred late in hominin evolution, with speech reaching its present level of autonomy only in our own species, Homo sapiens.
Perspective discursive et influence translinguistique
Authors: Benazzo Sandra , Andorno Cecilia , Interlandi Grazia , Patin Cédric
Published: May 2013

This paper aims to study perspective-taking in L2 discourse at the level of utterance information structure. Many studies have shown how principles of discourse organization partly reflect lexico-grammatical structures available in a given language, and how difficult it is to reorganize L1 discursive habits when acquiring an L2 in adulthood. In this study we compare how L2 learners of Romance languages (French, Italian), with either a Romance or a Germanic language as an L1, organize the information structure of utterances relating contrasting events. Native speakers of Germanic and Romance languages show systematic differences in the selection of the information unit — referential entities or predicate polarity — on which the contrast is highlighted (Dimroth et al. 2010) ; moreover, they differ in the lexical, prosodic and morpho-syntactic means used to achieve this goal. Our data show that L2 learners can adopt the target language perspective in the selection of the information unit to contrast, when the input offers clear evidence for it. However, their choice of linguistic means reveals both the influence of the L1 and the role of more general acquisitional principles, which are still active at the advanced level.
Typological constraints in foreign language acquisition
Authors: Iakovleva Tatiana
Published: May 2013

This study examines the impact of typological constraints on second language acquisition. It explores the hypothesis of a conceptual transfer from first to foreign language (L1 to L2). Based on Talmy’s (2000) distinction between Verb- and Satellite-framed languages, corpus-based analyses compare descriptions of voluntary motion events along three paths (up, down, across), elicited in a controlled situation from native speakers (Russian, English) and Russian learners at two levels (upper- intermediate and advanced) acquiring English in a classroom setting. Results show that in spite of considerable differences between Russian and English native speakers’ performance, particularly with respect to the relative variability in their lexicalization patterns, idiosyncratic forms and structures produced by L2 learners rarely mirror motion conceptualization in their first language, which suggests the absence of a substantial transfer from L1.
Linguistic encoding of motion events in English and French
Authors: Soroli Efstathia , Sahraoui Halima , Sacchett Carol
Published: May 2013

Languages show differences in how they encode motion in discourse: Verb-framed languages lexicalize Path in the verb, leaving Manner peripheral or implicit; Satellite-framed languages lexicalize Manner together with Path adjuncts. The present study investigates: 1) the extent to which such typological constraints affect the verbalizations of second language learners (English learners of French) and of aphasic speakers (English and French speakers with agrammatism) — who typically show dissociations between lexical and syntactic knowledge — in comparison to controls (English and French native speakers); as well as 2) the role of language-independent factors (level of acquisition, syndrome type). Despite some similarities between learners and speakers with aphasia due to language-independent factors, the findings suggest typologically constrained verbalizations in all groups, as well as diverging strategies that may reflect distinct underlying conceptualization processes.
Aromatic plant species in agricultural production systems based on marginal soils.
Authors: Rao E. V. S. P.
Published: May 2013

Globally, agricultural production systems are under greater pressure than they were at any time in human history. Although agriculture is expected to feed the populations with nutritious food, land availability for food production is becoming limited. In addition, competition for agricultural lands from non-agricultural uses, the need for non-food commodities, degradation of soils, impending effects of climate change have necessitated proper management of natural resources for meeting the demands of mankind. In this context, one good strategy is to arrest degradation of natural resources including soils, economical use of marginal and degraded soils through diversification of agricultural crops for food and industrial and environmental purposes. Aromatic plants that yield essential oils that are used widely in flavour, fragrance and health-care industries have been considered important diversification candidates in such a scenario. Scientific evidences suggest that aromatic plants have multiple advantages in being adaptable to marginal/degraded soils and of having the ability to arrest some soil degradation processes. In order to derive optimum economic and ecological advantages of aromatic plants, it is necessary to develop proper cropping systems involving aromatic crops, identify most suitable agro-ecological conditions for their growth, develop good agronomic practices for their cultivation in marginal/degraded soils, adopt proper post-harvest processing methods and establish marketing channels. In this review, scientific evidence of suitability of some aromatic plant species to soils prone to erosion, low fertility, moisture stress conditions, salinity and sodicity, contamination are presented. Value-chain management of aromatic crops and their products in order to derive economic and ecological advantage is necessary.
The Compression of Perceived Time in a Hot Environment Depends on Physiological and Psychological Factors
Authors: Tamm Maria , Jakobson Ainika , Havik Merle , Burk Andres , Timpmann Saima , Allik Jüri , Ööpik Vahur , Kreegipuu Kairi
Published: May 2013

The human perception of time was observed under extremely hot conditions. Young healthy men performed a time production task repeatedly in 4 experimental trials in either a temperate (22 °C, relative humidity 35%) or a hot (42 °C, relative humidity 18%) environment and with or without a moderate-intensity treadmill exercise. Within 1 hour, the produced durations indicated a significant compression of short intervals (0.5 to 10 s) in the combination of exercising and high ambient temperature, while neither variable/condition alone was enough to yield the effect. Temporal judgement was analysed in relation to different indicators of arousal, such as critical flicker frequency (CFF), core temperature, heart rate, and subjective ratings of fatigue and exertion. The arousal-sensitive internal clock model (originally proposed by Treisman) is used to explain the temporal compression while exercising in heat. As a result, we suggest that the psychological response to heat stress, the more precisely perceived fatigue, is important in describing the relationship between core temperature and time perception. Temporal compression is related to higher core temperature, but only if a certain level of perceived fatigue is accounted for, implying the existence of a thermoemotional internal clock.
Sex Differences in Residency of Adult Spotted Seatrout in a Louisiana Estuary
Authors: Callihan Jody L. , Cowan James H. , Harbison Michael D.
Published: May 2013

Spotted Seatrout Cynoscion nebulosus is the most highly sought after recreational species along the U.S. Gulf coast. However, movement information for this economically and ecologically important species is currently limited to data from mark–recapture studies. We used remote acoustic telemetry, a high-resolution, fisheries-independent technique, to examine the residency of adult Spotted Seatrout (n = 172) in a Louisiana estuary, Calcasieu Lake (∼300 km2). An estuarine-wide array of 60 receivers was deployed for a 2.5-year period (May 2007–October 2009) to detect and quantify how long fish were present in the estuary and determine the proportion of fish that emigrated from the system. We then determined how these metrics (detection period and emigration) were related to fish size, sex, and season of release. Emigration was highly seasonal and occurred exclusively during late spring and summer when water temperatures exceeded 24°C. Surprisingly, male Spotted Seatrout, regardless of their size, were more likely than females to “permanently” emigrate from the estuary (i.e., not return within the 1-year battery life of transmitters) as evidenced by their shorter mean detection periods (males = 134 d, females = 177 d) and higher incidence of emigration (29–42% of males, but only 14–16% of females emigrated). Assessment and management strategies for this species may be improved by explicitly considering this behavioral difference between sexes. Namely, conducting stock assessments at a finer spatial scale (i.e., estuarine-specific versus state-wide) appears warranted given the high estuarine fidelity of females (∼85%), which exacerbates their potential for localized depletions due to anthropogenic stressors (e.g., fishing pressure, habitat alteration, or pollution).

Received October 12, 2012; accepted February 26, 2013