bluuebunny/crossref_metadata_2025 huggingface dataset:
Dichoptic Viewing Methods for Binocular Rivalry Research: Prospects for Large-Scale Clinical and Genetic Studies
Authors: Law Phillip C. F. , Paton Bryan K. , Thomson Richard H. , Liu Guang B. , Miller Steven M. , Ngo Trung T.
Published: November 2013

Binocular rivalry (BR) is an intriguing phenomenon that occurs when two different images are presented, one to each eye, resulting in alternation orrivalrybetween the percepts. The phenomenon has been studied for nearly 200 years, with renewed and intensive investigation over recent decades. Therateof perceptual switching has long been known to vary widely between individuals but to be relatively stable within individuals. A recent twin study demonstrated that individual variation in BR rate is under substantial genetic control, a finding that also represented the first report, using a large study, of genetic contribution for any post-retinal visual processing phenomenon. The twin study had been prompted by earlier work showing BR rate was slow in the heritable psychiatric condition, bipolar disorder (BD). Together, these studies suggested that slow BR may represent an endophenotype for BD, and heralded the advent of modern clinical and genetic studies of rivalry. This new focus has coincided with rapid advances in 3D display technology, but despite such progress, specific development of technology for rivalry research has been lacking. This review therefore compares different display methods for BR research across several factors, including viewing parameters, image quality, equipment cost, compatibility with other investigative methods, subject group, and sample size, with a focus on requirements specific to large-scale clinical and genetic studies. It is intended to be a resource for investigators new to BR research, such as clinicians and geneticists, and to stimulate the development of 3D display technology for advancing interdisciplinary studies of rivalry.
Methane storage in tea clathrates
Authors: Wang Weixing , Zeng Peiyu , Long Xiyi , Huang Jierong , Liu Yao , Tan Bien , Sun Luyi
Published: November 2013

Kinetics of methane clathrate formation can be significantly accelerated by ingredients in tea infusions with a capacity of up to 172 v/v.
Vapochemically and mechanochemically reversible polymerization/depolymerization of S–Fe–Cu carbonyl clusters
Authors: Lin Chien-Nan , Jhu Wei-Ting , Shieh Minghuey
Published: November 2013

A solid-state reversible transformation was achieved between 0D and 1D SFe3Cu2-based carbonyl clustersviavapochemical and mechanochemical reactions.
Bromo- and thiomaleimides as a new class of thiol-mediated fluorescence ‘turn-on’ reagents
Authors: Youziel Judith , Akhbar Ahmed R. , Aziz Qadeer , Smith Mark E. B. , Caddick Stephen , Tinker Andrew , Baker James R.
Published: November 2013

Bromo- and thiomaleimides are shown to serve as highly effective quenchers of a covalently attached fluorophore. Reactions with thiols that lead to removal of the maleimide conjugation, or detachment of the fluorophore from the maleimide, result in ‘turn-on’ of the fluorescence.
Plasmonic enhancement of photocatalysis over Ag incorporated AgI hollow nanostructures
Authors: An Changhua , Wang Jizhuang , Liu Junxue , Wang Shutao , Zhang Qin-Hui
Published: November 2013

Hollow-structured AgI nanoboxes and AgI:Ag hollow cube-tetrapods with good structural and photocatalytic stability has been synthesized via a facile self-templating method.
c-Src-induced activation of ceramide metabolism impairs membrane microdomains and promotes malignant progression by facilitating the translocation of c-Src to focal adhesions
Authors: Kajiwara Kentaro , Yamada Takayuki , Bamba Takeshi , Fukusaki Eiichiro , Imamoto Fumio , Okada Masato , Oneyama Chitose
Published: November 2013

The proto-oncogenic tyrosine kinase c-Src is up-regulated in various human cancers, implicating its role in tumour progression. Upon activation, c-Src translocates to focal adhesions and initiates intracellular signalling cascades that promote malignant transformation, but the underlying mechanisms for c-Src translocation remain unclear. In the present study we show that c-Src up-regulation perturbs sphingolipid/cholesterol-enriched membrane microdomains by activating ceramide synthesis, resulting in promotion of c-Src translocation. Using an inducible c-Src expression system in Csk (C-terminal Src kinase)-deficient fibroblasts, we found that translocation of c-Src to focal adhesions/podosomes occurs in the later stages of cell transformation. Activated c-Src is liberated from microdomains and promotes the phosphorylation of FAK (focal adhesion kinase) and cortactin localized to focal adhesions/podosomes. In parallel with these events, anabolic metabolism of ceramides is activated by up-regulation of the de novo synthesis pathway. Inhibition of ceramide conversion into glucosylceramide promotes liberation of c-Src from microdomains, and inhibition of de novo ceramide synthesis restores the microdomain distribution of c-Src and suppresses malignant phenotypes such as increased cell motility and anchorage-independent cell growth. These results suggest that c-Src-induced activation of ceramide synthesis impairs the integrity of microdomains and contributes to malignant progression by promoting the translocation of c-Src to focal adhesions/podosomes.
RAD-6: pyrimidine synthesis and radiation sensitivity in Caenorhabditis elegans
Authors: Merry Alyce , Qiao Mengmeng , Hasler Martin , Kuwabara Patricia E.
Published: November 2013

The Caenorhabditis elegans rad-6 (radiation-sensitive-6) mutant was isolated over 25 years ago in a genetic screen that identified mutants with enhanced sensitivity to DNA damaging agents. In the present paper we describe the molecular identification of the rad-6 gene and reveal that it encodes the bifunctional UMP synthase protein, which carries catalytic activities for OPRTase (orotate phosphoribosyltransferase) and ODCase (orotate monophosphate decarboxylase), key enzymes in the de novo pathway of pyrimidine synthesis. Mutations in genes encoding de novo pathway enzymes cause varying degrees of lethality and pleiotropic phenotypes in many organisms, including humans. We have examined how the absence of rad-6 activity leads to both UV-C hypersensitivity and a decline in both metabolic rate and lifespan. We discuss how rad-6 mutants adapt to the loss of the de novo pathway through a dependency on pyrimidine salvage. We establish further that rad-6(mn160) mutants lack ODCase activity because they are resistant to the cytotoxic effects of 5-FOA (5-fluoroorotic acid). Our results have also led to the identification of a metabolic sensor affecting survival and metabolism, which is dependent on the maternal rad-6 genotype.
Arl6IP1 has the ability to shape the mammalian ER membrane in a reticulon-like fashion
Authors: Yamamoto Yasunori , Yoshida Asuka , Miyazaki Naoyuki , Iwasaki Kenji , Sakisaka Toshiaki
Published: November 2013

The ER (endoplasmic reticulum) consists of the nuclear envelope and a peripheral network of membrane sheets and tubules. Two classes of the evolutionarily conserved ER membrane proteins, reticulons and REEPs (receptor expression-enhancing proteins)/DP1 (deleted in polyposis locus 1)/Yop1 (YIP 1 partner), shape high-curvature ER tubules. In mammals, four members of the reticulon family and six members of the REEP family have been identified so far. In the present paper we report that Arl6IP1(ADP-ribosylation factor-like 6 interacting protein 1), an anti-apoptotic protein specific to multicellular organisms, is a potential player in shaping the ER tubules in mammalian cells. Arl6IP1, which does not share an overall primary sequence homology with reticulons, harbours reticulon-like short hairpin transmembrane domains and binds to atlastin, a GTPase that mediates the formation of the tubular ER network. Overexpression of Arl6IP1 induced extensive tubular structures of the ER and excluded a luminal protein. Furthermore, overexpression of Arl6IP1 stabilized the ER tubules, allowing the cells to maintain the ER tubules even in the absence of microtubules. Arl6IP1 constricted liposomes into tubules. The short hairpin structures of the transmembrane domains were required for the membrane-shaping activity of Arl6IP1. The results of the present study indicate that Arl6IP1 has the ability to shape high-curvature ER tubules in a reticulon-like fashion.
Preparation and characterisation of N‐doped SiO2 at TiO2 core–shell structural materials and its photocatalytic property
Authors: Liu Hui , Lv Ting , Li Guangjun , Dong Xiaonan , Zhu Zhenfeng
Published: November 2013

N‐doped SiO2 at TiO2 core–shell structural materials has been synthesised successfully via a simple two‐step method. First, SiO2 spheres were obtained by using a slightly modified Stöber process. Then, N‐doped SiO2 at TiO2 were prepared via coating SiO2 template with TiO2 layers, followed by N‐doping using NH4NO3 as the N source. According to Kato et al. the as‐obtained products were well characterised by X‐ray diffraction, scanning electron microscopy, transmission electron microscopy, X‐ray photoelectron spectroscopy and UV–vis absorption spectra. The photocatalytic activity of the as‐prepared products was evaluated by photocatalytic decolourisation of rhodamine B aqueous solution at ambient temperature under UV and visible‐light irradiation. The experimental results showed that the diameter of N‐doped SiO2 at TiO2 spheres was about 250 nm and the thickness of the TiO2 shell was 10–20 nm, the products exhibited a high photocatalytic activity because N atoms were incorporated into the titanium dioxide planes to decrease the bandgap energy.
Role of interfacial surface area on the physical phenomena of nanocomposites
Authors: Reddy C.C. , Tiwana A.P.S. , Gupta A. , Chahal J.S.
Published: November 2013

Improvement in the material properties of nanocomposite materials is often stated to be because of the interfacial surface area (ISA) or inter‐filler distance (IFD). Several models were suggested for understanding the material properties of nanocomposites. The occurrence of a thin surface layer surrounding nanoparticles, where the material properties would be different from the filler and filled material, has been proposed earlier. In the absence of a commercial technology to obtain the ideal placement of nanoparticles at specified locations in the material matrix, the particle dispersion is driven by practical limitations. If the surface layer and IFD are the criteria for goodness of performance, ideally, both of these should tend towards improvements with increase in filler content. However, experimental evidence suggests the saturation of material properties with filler content. This saturation needs to be fully understood in order to optimise filler content. In this reported work, the effect of filler content on inter‐particle distance and ISA in nanocomposites has been investigated. The reason for the observed saturation in material properties with filler content is explained. It is mathematically shown that the ISA also shows similar characteristics as a physical phenomenon supporting the role of the ISA in the material properties of nanocomposites.
Interfacial X‐ray photospectrometry study of In0.53Ga0.47As under different passivation treatments for metal oxide semiconductor field effect transistor devices
Authors: Mohd Razip Wee M.F. , Dehzangi A. , Wichmann N. , Bollaert S. , Yeop Majlis Burhanuddin
Published: November 2013

In this reported work, comparison is made of a passivation treatment of a III–V compound semiconductor using ammonia and ammonium sulphide solution. The treatment is applied on In0.53Ga0.47As which is chosen for its high mobility especially in high electron mobility transistors. The samples were treated with various parameters such as precursor, vacuum condition and different chemical solutions. Then, samples were deposited with the high k ‐dielectric Al2O3 (4 nm thickness) using the atomic layer deposition technique. Five different passivation treatments were used to give proper comparison. Native oxide elements and contaminants were inspected at the interface of the oxide layer and the substrate using X‐ray photospectrometry in different angles (25° and 70°). The results indicate the effectiveness of some treatments to eliminate the oxide of gallium and arsenic with a slight presence of indium oxide.
Secondary instability of roughness-induced transient growth
Authors: Denissen Nicholas A. , White Edward B.
Published: November 2013

Calculations are performed to analyze the stability of steady roughness-induced transient growth to unsteady fluctuations. The basic states consist of an optimal transient growth model and a previously computed direct numerical simulation that fully resolves the three-dimensional roughness element. It is shown that sub-optimal transient growth produced by surface roughness is much more susceptible to destabilization than optimal perturbation predictions. The factors contributing to this behavior are analyzed in detail. Scaling properties from experiments allow computation of stability bounds for realistic surface roughness. These results are also used to explain the critical behavior seen in transition behind three-dimensional roughness elements.
Exploring high temperature phenomena related to post-detonation using an electric arc
Authors: Dai Z. R. , Crowhurst J. C. , Grant C. D. , Knight K. B. , Tang V. , Chernov A. A. , Cook E. G. , Lotscher J. P. , Hutcheon I. D.
Published: November 2013

We report a study of materials recovered from a uranium-containing plasma generated by an electric arc. The device used to generate the arc is capable of sustaining temperatures of an eV or higher for up to 100 μs. Samples took the form of a 4 μm-thick U238 film deposited onto 8 pairs of 17 μm-thick Cu electrodes supported on a 25 μm-thick Kapton backing and sandwiched between glass plates. Materials recovered from the glass plates and around the electrode tips after passage of an arc were characterized using scanning and transmission electron microscopy. Recovered materials included a variety of crystalline compounds (e.g., UO2, UC2, UCu5,) as well as mixtures of uranium and amorphous glass. Most of the materials collected on the glass plates took the form of spherules having a wide range of diameters from tens of nanometers to tens of micrometers. The composition and size of the spherules depended on location, indicating different chemical and physical environments. A theoretical analysis we have carried out suggests that the submicron spherules presumably formed by deposition during the arc discharge, while at the same time the glass plates were strongly heated due to absorption of plasma radiation mainly by islands of deposited metals (Cu, U). The surface temperature of the glass plates is expected to have risen to ∼2300 K thus producing a liquefied glass layer, likely diffusions of the deposited metals on the hot glass surface and into this layer were accompanied by chemical reactions that gave rise to the observed materials. These results, together with the compact scale and relatively low cost, suggest that the experimental technique provides a practical approach to investigate the complex physical and chemical processes that occur when actinide-containing material interacts with the environment at high temperature, for example, during fallout formation following a nuclear detonation.
Electrical conductivity in oxygen-deficient phases of tantalum pentoxide from first-principles calculations
Authors: Bondi Robert J. , Desjarlais Michael P. , Thompson Aidan P. , Brennecka Geoff L. , Marinella Matthew J.
Published: November 2013

We apply first-principles density-functional theory (DFT) calculations, ab-initio molecular dynamics, and the Kubo-Greenwood formula to predict electrical conductivity in Ta2Ox (0 ≤ x ≤ 5) as a function of composition, phase, and temperature, where additional focus is given to various oxidation states of the O monovacancy (VOn; n = 0,1+,2+). In the crystalline phase, our DFT calculations suggest that VO0 prefers equatorial O sites, while VO1+ and VO2+ are energetically preferred in the O cap sites of TaO7 polyhedra. Our calculations of DC conductivity at 300 K agree well with experimental measurements taken on Ta2Ox thin films (0.18 ≤ x ≤ 4.72) and bulk Ta2O5 powder-sintered pellets, although simulation accuracy can be improved for the most insulating, stoichiometric compositions. Our conductivity calculations and further interrogation of the O-deficient Ta2O5 electronic structure provide further theoretical basis to substantiate VO0 as a donor dopant in Ta2O5. Furthermore, this dopant-like behavior is specific to the neutral case and not observed in either the 1+ or 2+ oxidation states, which suggests that reduction and oxidation reactions may effectively act as donor activation and deactivation mechanisms, respectively, for VOn in Ta2O5.
A double-threshold technique for fast time-correspondence imaging
Authors: Li Ming-Fei , Zhang Yu-Ran , Liu Xue-Feng , Yao Xu-Ri , Luo Kai-Hong , Fan Heng , Wu Ling-An
Published: November 2013

We present a robust imaging method based on time-correspondence imaging and normalized ghost imaging (GI) that sets two thresholds to select the reference frame exposures for image reconstruction. This double-threshold time-correspondence imaging protocol always gives better quality and signal-to-noise ratio than previous GI schemes, and is insensitive to surrounding noise. Moreover, only simple add and minus operations are required while less data storage space and computing time are consumed; thus, faster imaging speeds are attainable. The protocol offers a general approach applicable to all GI techniques and marks a further step forward towards real-time practical applications of correlation imaging.
Rotational relaxation of CS by collision with ortho- and para-H2 molecules
Authors: Denis-Alpizar Otoniel , Stoecklin Thierry , Halvick Philippe , Dubernet Marie-Lise
Published: November 2013

Quantum mechanical investigation of the rotationally inelastic collisions of CS with ortho- and para-H2 molecules is reported. The new global four-dimensional potential energy surface presented in our recent work is used. Close coupling scattering calculations are performed in the rigid rotor approximation for ortho- and para-H2 colliding with CS in the j = 0–15 rotational levels and for collision energies ranging from 10−2 to 103 cm−1. The cross sections and rate coefficients for selected rotational transitions of CS are compared with the ones previously reported for the collision of CS with He. The largest discrepancies are observed at low collision energy, below 1 cm−1. Above 10 cm−1, the approximation using the square root of the relative mass of the colliders to calculate the cross sections between a molecule and H2 from the data available with 4He is found to be a good qualitative approximation. The rate coefficients calculated with the electron gas model for the He-CS system show more discrepancy with our accurate results. However, scaling up these rates by a factor of 2 gives a qualitative agreement.
Laser-induced breakdown and damage generation by nonlinear frequency conversion in ferroelectric crystals: Experiment and theory
Authors: Louchev Oleg A. , Hatano Hideki , Saito Norihito , Wada Satoshi , Kitamura Kenji
Published: November 2013

Using our experimental data for ns pulsed second harmonic generation (SHG) by periodically poled stoichiometric LiTaO3 (PPSLT) crystals, we consider in detail the mechanism underlying laser-induced damage in ferroelectric crystals. This mechanism involves generation and heating of free electrons, providing an effective kinetic pathway for electric breakdown and crystal damage in ns pulsed operation via combined two-photon absorption (TPA) and induced pyroelectric field. In particular, a temperature increase in the lattice of ≈1 K induced initially by ns SHG and TPA at the rear of operating PPSLT crystal is found to induce a gradient of spontaneous polarization generating a pyroelectric field of ≈10 kV/cm, accelerating free electrons generated by TPA to an energy of ≈10 eV, followed by impact ionization and crystal damage. Under the damage threshold for ns operation, the impact ionization does not lead to the avalanche-like increase of free electron density, in contrast to the case of shorter ps and fs pulses. However, the total number of collisions by free electrons, ≈1018 cm−3 (generated during the pulse and accelerated to the energy of ≈10 eV), can produce widespread structural defects, which by entrapping electrons dramatically increase linear absorption for both harmonics in subsequent pulses, creating a positive feedback for crystal lattice heating, pyroelectric field and crystal damage. Under pulse repetition, defect generation starting from the rear of the crystal can propagate towards its center and front side producing damage tracks along the laser beam and stopping SHG. Theoretical analysis leads to numerical estimates and analytical approximation for the threshold laser fluence for onset of this damage mechanism, which agree well with our (i) experiments for the input 1064 nm radiation in 6.8 kHz pulsed SHG by PPSLT crystal, (ii) pulsed low frequency 532 nm radiation transmission experiments, and also (iii) with the data published for other nonlinear crystals and operated wavelengths.
Limited and time-delayed internal resource allocation generates oscillations and chaos in the dynamics of citrus crops
Authors: Ye Xujun , Sakai Kenshi
Published: November 2013

Alternate bearing or masting is a yield variability phenomenon in perennial crops. The complex dynamics in this phenomenon have stimulated much ecological research. Motivated by data from an eight-year experiment with forty-eight individual trees, we explored the mechanism inherent to these dynamics in Satsuma mandarin (Citrus unshiu Marc.). By integrating high-resolution imaging technology, we found that the canopy structure and reproduction output of individual citrus crops are mutually dependent on each other. Furthermore, it was revealed that the mature leaves in early season contribute their energy to the fruiting of the current growing season, whereas the younger leaves show a delayed contribution to the next growing season. We thus hypothesized that the annual yield variability might be caused by the limited and time-delayed resource allocation in individual plants. A novel lattice model based on this hypothesis demonstrates that this pattern of resource allocation will generate oscillations and chaos in citrus yield.
Numerical exploration of the origin of aerodynamic enhancements in [low-Reynolds number] corrugated airfoils
Authors: Barnes Caleb J. , Visbal Miguel R.
Published: November 2013

This paper explores the flow structure of a corrugated airfoil using a high-fidelity implicit large eddy simulation approach. The first three-dimensional simulations for a corrugated wing section are presented considering a range of Reynolds numbers of Rec = 5 × 103 to 5.8 × 104 bridging the gap left by previous numerical and experimental studies. Several important effects are shown to result from the corrugations in the leading-edge region. First, interaction between the detached shear layer and the first corrugation peak promotes recirculation upstream and enhances transition to turbulence due to flow instabilities. Thus, early transitional flow develops on the corrugated wing which helps to delay stall even at Reynolds numbers as low as Rec = 1 × 104. Transition is shown to occur as early as Rec = 7.5 × 103 and quickly advances toward the leading-edge as Reynolds number is increased. Modification of the first corrugation peak height produces significantly reduced separation and improved aerodynamic forces demonstrating the sensitivity of flow behavior to leading-edge geometry. Second, the unusual orientation of the corrugated surface and strong suction resulting from rapidly turning fluid over the separated region upstream of the first corrugation produces a new effect which serves to reduce drag. This effect was amplified through the enhanced interaction produced by a modified geometry. Corrugations were found to be most advantageous in the leading-edge region and could be optimized to properly take advantage of the flow field under different operating conditions.
Functional Mn–Mgk cation complexes in GaN featured by Raman spectroscopy
Authors: Devillers T. , Leite D. M. G. , Dias da Silva J. H. , Bonanni A.
Published: November 2013

The evolution of the optical branch in the Raman spectra of (Ga,Mn)N:Mg epitaxial layers as a function of the Mn and Mg concentrations, reveals the interplay between the two dopants. We demonstrate that the various Mn-Mg-induced vibrational modes can be understood in the picture of functional Mn–Mgk complexes formed when substitutional Mn cations are bound to k substitutional Mg through nitrogen atoms, the number of ligands k being driven by the ratio between the Mg and the Mn concentrations.
Polarization doping and the efficiency of III-nitride optoelectronic devices
Authors: Kivisaari Pyry , Oksanen Jani , Tulkki Jukka
Published: November 2013

The intrinsic polarization is generally considered a nuisance in III-nitride devices, but recent studies have shown that it can be used to enhance p- and n-type conductivity and even to replace impurity doping. We show by numerical simulations that polarization-doped light-emitting diode (LED) structures have a significant performance advantage over conventional impurity-doped LED structures. Our results indicate that polarization doping decreases electric fields inside the active region and potential barriers in the depletion region, as well as the magnitude of the quantum-confined Stark effect. The simulations also predict at least an order of magnitude increase in the current density corresponding to the maximum efficiency (i.e., smaller droop) as compared to impurity-doped structures. The obtained high doping concentrations could also enable, e.g., fabrication of III-N resonant tunneling diodes and improved ohmic contacts.
Metabolic profile analysis of a single developing zebrafish embryo via monitoring of oxygen consumption rates within a microfluidic device
Authors: Huang Shih-Hao , Huang Kuo-Sheng , Yu Chu-Hung , Gong Hong-Yi
Published: November 2013

A combination of a microfluidic device with a light modulation system was developed to detect the oxygen consumption rate (OCR) of a single developing zebrafish embryo via phase-based phosphorescence lifetime detection. The microfluidic device combines two components: an array of glass microwells containing Pt(II) octaethylporphyrin as an oxygen-sensitive luminescent layer and a microfluidic module with pneumatically actuated glass lids above the microwells to controllably seal the microwells of interest. The total basal respiration (OCR, in pmol O2/min/embryo) of a single developing zebrafish embryo inside a sealed microwell has been successfully measured from the blastula stage (3 h post-fertilization, 3 hpf) through the hatching stage (48 hpf). The total basal respiration increased in a linear and reproducible fashion with embryonic age. Sequentially adding pharmacological inhibitors of bioenergetic pathways allows us to perform respiratory measurements of a single zebrafish embryo at key developmental stages and thus monitor changes in mitochondrial function in vivo that are coordinated with embryonic development. We have successfully measured the metabolic profiles of a single developing zebrafish embryo from 3 hpf to 48 hpf inside a microfluidic device. The total basal respiration is partitioned into the non-mitochondrial respiration, mitochondrial respiration, respiration due to adenosine triphosphate (ATP) turnover, and respiration due to proton leak. The changes in these respirations are correlated with zebrafish embryonic development stages. Our proposed platform provides the potential for studying bioenergetic metabolism in a developing organism and for a wide range of biomedical applications that relate mitochondrial physiology and disease.
The effect of oxygen vacancies on the electronic phase transition in La1/3Sr2/3FeO3 films
Authors: Sichel-Tissot Rebecca J. , Devlin Robert C. , Ryan Philip J. , Kim Jong-Woo , May Steven J.
Published: November 2013

Synchrotron x-ray diffraction and electrical resistivity were used to probe the electronic phase transition in two strained La1/3Sr2/3FeO3 films on (001) SrTiO3 substrates, one nominally stoichiometric and one with a higher concentration of oxygen vacancies. We present evidence that oxygen vacancies inhibit the size of charge ordered domains and reduce the abruptness of the phase transition. Additionally, the correlation lengths measured from (4/3 4/3 4/3) peaks, arising from charge disproportionation, increase rapidly across the transition, suggesting that the resistivity increase at the transition temperature is caused by the nucleation and growth of charge ordered domains.
Anisotropic terahertz complex conductivities in oriented polythiophene films
Authors: Unuma Takeya , Umemoto Atsuhiro , Kishida Hideo
Published: November 2013

We investigate polarization-resolved terahertz (THz) transmission through a doped polythiophene film consisting of partially oriented polymer chains. The THz complex conductivities are found to be significantly larger for polarization parallel to the principal direction of orientation than for polarization perpendicular to it, but involve no change in spectral shape with polarization. This indicates that charge transport occurs mainly along polythiophene chains with their in-plane angle distribution, ruling out a possible interchain contribution, whose spectral shape should be sensitive to polarization.
Enhanced ferroelectric properties and thermal stability of nonstoichiometric 0.92(Na0.5Bi0.5)TiO3-0.08(K0.5Bi0.5)TiO3 single crystals
Authors: Zhang Haiwu , Chen Chao , Zhao Xiangyong , Deng Hao , Li Long , Lin Di , Li Xiaobing , Ren Bo , Luo Haosu , Yan Jun
Published: November 2013

Bi deficient, Mn doped 0.92(Na0.5Bi0.5)TiO3-0.08(K0.5Bi0.5)TiO3 single crystals were grown by carefully controlled top-seeded solution growth method. Local structures were investigated by transmission electron microscopy. The site occupation and valence state of manganese were characterized by electron paramagnetic resonance spectrum. The leakage current density in the as-grown single crystals is effectively depressed. The introduced defect complexes suppress the temperature induced phase transformation, increasing the depolarization temperature (165 °C) and thermal stability of ferroelectric properties.
Ultrafast and steady-state laser heating effects on electron relaxation and phonon coupling mechanisms in thin gold films
Authors: Hopkins Patrick E. , Duda John C. , Kaehr Bryan , Wang Zhou Xiao , Peter Yang C.-Y. , Jones Reese E.
Published: November 2013

We study the scattering mechanisms driving electron-phonon relaxation in thin gold films via pump-probe time-domain thermoreflectance. Electron-electron scattering can enhance the effective rate of electron-phonon relaxation when the electrons are out of equilibrium with the phonons. In order to correctly and consistently infer electron-phonon coupling factors in films on different substrates, we must account for the increase in steady-state lattice temperature due to laser heating. Our data provide evidence that a thermalized electron population will not directly exchange energy with the substrate during electron-phonon relaxation, whereas this pathway can exist between a non-equilibrium distribution of electrons and a non-metallic substrate.
Instability of the radial flow over a rotating disk in a separated edgewise stream
Authors: Raghav Vrishank , Komerath Narayanan
Published: November 2013

We present velocity field measurements showing the instability of the radial flow over a rotating disk in a separated flow due to an edgewise freestream. A uniform edgewise stream significantly modifies the radial jet profile. Under separated flow conditions, co-rotating vortical structures form at the edge of the radial jet layer. The results establish that the discrete structures formed in the breakup of the radial flow layer on a rotor blade in retreating blade stall are also seen in the case of flow over a rotating disk.
Resistance memory device of La0.7Sr0.3MnO3 on Si nanotips template
Authors: Chong C. W. , Huang M. J. , Han H. C. , Lin Y. K. , Chiu J. M. , Huang Y. F. , Lin H. J. , Pi T. W. , Lin J. G. , Chen L. C. , Chen K. H. , Chen Y. F.
Published: November 2013

Modifiable resistance switching (RS) is demonstrated in devices made of La0.7Sr0.3MnO3 (LSMO) on heavy-doped n-type silicon nanotips (n+-SiNTs) template. The high RS ratio of 900% with low switching voltage (±2 V) and read voltage (+0.1 V) prove the applicability of such devices for resistance memory cells. The RS mechanism can be modulated from interfacial charge transfer to Mott metal-insulator transition, dependent on the number of defect state at the surface of LSMO in association with the morphology of SiNTs.
Generation of cumulative jets during underwater explosion of copper wires in the “X-pinch” configuration
Authors: Shafer D. , Toker G. , Gurovich V. Tz. , Krasik Ya. E.
Published: November 2013

The results of experiments with underwater electrical explosion of 0.1 mm diameter copper wires in X-pinch configuration are presented. A pulsed generator producing a ∼30 kA-amplitude current with a ∼65 ns rise time was used for the explosion of the wires. Shadowgraph and shearing interferometry techniques were applied for optical diagnostics. Evidence of fast-moving copper jets, originating from the location of the intersection of the exploding wires, is reported. Simultaneous measurement of the expansion of the wires, shock waves, and copper jets showed that the dynamics of the jets strongly resemble the classic problem of a collision of two planes, producing two consecutive cumulative jets.
Structure of nanoscale gas bubbles in metals
Authors: Caro A. , Schwen D. , Martinez E.
Published: November 2013

A usual way to estimate the amount of gas in a bubble inside a metal is to assume thermodynamic equilibrium, i.e., the gas pressure P equals the capillarity force 2γ/R, with γ the surface energy of the host material and R the bubble radius; under this condition there is no driving force for vacancies to be emitted or absorbed by the bubble. In contrast to the common assumption that pressure inside a gas or fluid bubble is constant, we show that at the nanoscale this picture is no longer valid. P and density can no longer be defined as global quantities determined by an equation of state (EOS), but they become functions of position because the bubble develops a core-shell structure. We focus on He in Fe and solve the problem using both continuum mechanics and empirical potentials to find a quantitative measure of this effect. We point to the need of redefining an EOS for nanoscale gas bubbles in metals, which can be obtained via an average pressure inside the bubble. The resulting EOS, which is now size dependent, gives pressures that differ by a factor of two or more from the original EOS for bubble diameters of 1 nm and below.
Profile measurements of thin liquid films using reflectometry
Authors: Hanchak M. S. , Vangsness M. D. , Byrd L. W. , Ervin J. S. , Jones J. G.
Published: November 2013

Microscope-based reflectometry was used to measure the thickness profile of thin films of n-octane on silicon wafer substrates. Coupled with micro-positioning motorized stages and custom software, two-dimensional profiles of the film thickness from the adsorbed film (∼10 nm) to the intrinsic meniscus (∼1000 nm) were automatically and repeatedly measured. The reflectometer aperture was modified to provide better spatial resolution in areas of high curvature, the transition region, where evaporative flux is at a maximum. This technique will provide data for the validation of both existing and future models of thin film evaporation.
Long-season canola (Brassica napus L.) cultivars offer potential to substantially increase grain yield production in south-eastern Australia compared with current spring cultivars
Authors: Christy Brendan , O'Leary Garry , Riffkin Penny , Acuna Tina , Potter Trent , Clough Angela
Published: November 2013

Average yield of canola in the high-rainfall zone (HRZ) of southern Australia are about half the predicted potential yield based on seasonal water supply. Current cultivars of canola that are available to growers were not bred specifically for the HRZ and tend to be short-season types aimed at escaping water stress during grain filling in the drier regions of the cropping belt. In the HRZ, these cultivars fail to utilise all available growing-season water due to early maturity. Field experimentation and crop simulation studies across the HRZ landscape of south-eastern Australia were used to determine the increased yield potential of longer-season canola cultivars compared with short-season cultivars. In this study the Catchment Analysis Tool spatial modelling framework was used to determine the expected canola yields of three cultivars across the entire HRZ of south-eastern Australia. Hyola50 (‘spring-short’) was used to represent the current recommended spring-type canola cultivar within the HRZ and was evaluated against an unreleased long-season spring-type cultivar CBI8802 (‘spring-long’) and a newly released winter-type cultivar Taurus (‘winter’). Spring-long outperformed spring-short across much of the study area. Yield advantages of winter over spring-short were mainly confined to the coastal fringe of Victoria and Tasmania and small pockets in New South Wales where at one location the average yield over 50 growing seasons exceeded spring-short by up to 60% or 1.4 t/ha. The superior performance of spring-long, (up to 17% or 0.9 t/ha at one location) was over a wider area than winter (26.4 compared with 8.8 million ha for winter) and although the magnitude of the yield increase over spring-short was not as great as winter at some locations, the overall result determined that spring-long had the greater production potential. The superior performance of spring-long beyond the HRZ challenges the trend of selecting earlier maturing cultivars by current breeders following the abnormal sequence of dry years in an attempt to minimise yield loss due to water stress during grain filling. This study has provided breeders, growers and advisors with information on where in the HRZ a longer-season canola cultivar can be grown to improve overall crop productivity. It has also provided evidence that new canola types may be required to maximise grain yields not only for the HRZ but potentially also in lower rainfall regions.
Mechanism of resistance in Australian sugarcane parent clones to smut and the effect of hot water treatment
Authors: Bhuiyan Shamsul A. , Croft Barry J. , Deomano Emily C. , James Rebecca S. , Stringer Joanne K.
Published: November 2013

Resistance of sugarcane plants to smut is believed to be manifested by two mechanisms, (i) external resistance, governed by structural barrier of bud scale and/or chemical secretion from the bud, and (ii) internal resistance, regulated by interaction of plants and fungus within the plant tissue. Hot water treatments are routinely used to treat seed cane to eliminate a range of diseases including smut. It is believed that hot water treatment predisposes sugarcane plant to smut. This study was conducted to determine the resistance mechanisms of some important Australian parent clones, and their response to hot water treatment in relation to smut infection. Twenty-one clones, used regularly in the Australian sugarcane breeding program, were evaluated. Results showed that ~47% of clones had external and 33% had internal resistance mechanisms, indicating that parent clones selected for this study possessed diverse mechanism of resistance. There is a possibility some or all clones with internal resistance mechanisms could also possess external resistance mechanism. Except one highly susceptible clone (Q205) in one trial, none of the clones subject to hot water treatment became more susceptible to smut. Although some clones showed increased resistance after hot water treatment. These findings will benefit breeders in selecting parent materials in their crossing programs to develop smut-resistant cultivars.
Pragmatics re-established on its feet
Authors: Trognon Alain
Published: November 2013

The “Mixed Game Model” as a linguistic theory conceptualizes the natural ability of human beings: “competence-in-performance”. The theory rests on a holistic view of language and dialogue that takes into account the physically and socially complex and more or less chaotic universe we live in. Competence-in-performance is thereby rooted in human biology. This ability enables people to communicate in an extremely context-sensitive manner. It rests on the subtle integration of three fundamental registers of human mental functioning in dialogic communication: perception (including emotional perception), cognition, and natural language. This explains why the theory is called the Mixed Game. The Mixed Game defines language as dialogue, conceptualizing the components of natural language along action and reaction. The book gives us a new foundation to the pragmatics of the human communication system, a rigorous systematic methodology to study all kinds of dialogues, from the simplest to the more sophisticated, from the most informal to the most institutional or professional. This book also suggests various theoretical and practical developments. It is useful not only for linguists, but also for all researchers in psychology, sociology, and more generally in all the human sciences.
Mug Handle Affordance and Automatic Response Inhibition: Behavioural and Electrophysiological Evidence
Authors: Vainio L. , Ala-Salomäki H. , Huovilainen T. , Nikkinen H. , Salo M. , Väliaho J. , Paavilainen P.
Published: November 2013

Behavioural evidence has shown that the perception of an object's handle automatically activates the corresponding action representation. The activation appears to be inhibited if the object is a task-irrelevant prime mug that is presented very briefly prior to responding to the target arrow. The present study uses an electrophysiological indicator of automatic response priming, the lateralized readiness potential (LRP), to investigate the mechanisms of this inhibition effect. We presumed that this effect would reflect motor self-inhibition processes. The self-inhibition explanation of the effect would assume that the effect reflects activation-followed-by-inhibition observed rapidly after the offset of the prime at the primary motor cortex. However, the results showed that the effect is not associated with modulation of the early LRP deflections. In contrast, the inhibition manifested itself in the later LRP deflections that we assume to be linked to interference in the processing of response-related aspects of the target. We propose that the LRP pattern is similar to what would be predicted from the negative priming explanation of the effect. The study sheds light on understanding inhibition mechanisms associated with automatically activated affordance representations.
Binding of the auxiliary subunit TRIP8b to HCN channels shifts the mode of action of cAMP
Authors: Hu Lei , Santoro Bina , Saponaro Andrea , Liu Haiying , Moroni Anna , Siegelbaum Steven
Published: November 2013

Hyperpolarization-activated cyclic nucleotide–regulated cation (HCN) channels generate the hyperpolarization-activated cation current Ih present in many neurons. These channels are directly regulated by the binding of cAMP, which both shifts the voltage dependence of HCN channel opening to more positive potentials and increases maximal Ih at extreme negative voltages where voltage gating is complete. Here we report that the HCN channel brain-specific auxiliary subunit TRIP8b produces opposing actions on these two effects of cAMP. In the first action, TRIP8b inhibits the effect of cAMP to shift voltage gating, decreasing both the sensitivity of the channel to cAMP (K1/2) and the efficacy of cAMP (maximal voltage shift); conversely, cAMP binding inhibits these actions of TRIP8b. These mutually antagonistic actions are well described by a cyclic allosteric mechanism in which TRIP8b binding reduces the affinity of the channel for cAMP, with the affinity of the open state for cAMP being reduced to a greater extent than the cAMP affinity of the closed state. In a second apparently independent action, TRIP8b enhances the action of cAMP to increase maximal Ih. This latter effect cannot be explained by the cyclic allosteric model but results from a previously uncharacterized action of TRIP8b to reduce maximal current through the channel in the absence of cAMP. Because the binding of cAMP also antagonizes this second effect of TRIP8b, application of cAMP produces a larger increase in maximal Ih in the presence of TRIP8b than in its absence. These findings may provide a mechanistic explanation for the wide variability in the effects of modulatory transmitters on the voltage gating and maximal amplitude of Ih reported for different neurons in the brain.
Hill’s equation of muscle performance and its hidden insight on molecular mechanisms
Authors: Seow Chun Y.
Published: November 2013

Muscles shorten faster against light loads than they do against heavy loads. The hyperbolic equation first used by A.V. Hill over seven decades ago to illustrate the relationship between shortening velocity and load is still the predominant method used to characterize muscle performance, even though it has been regarded as purely empirical and lacking precision in predicting velocities at high and low loads. Popularity of the Hill equation has been sustained perhaps because of historical reasons, but its simplicity is certainly attractive. The descriptive nature of the equation does not diminish its role as a useful tool in our quest to understand animal locomotion and optimal design of muscle-powered devices like bicycles. In this Review, an analysis is presented to illustrate the connection between the historic Hill equation and the kinetics of myosin cross-bridge cycle based on the latest findings on myosin motor interaction with actin filaments within the structural confines of a sarcomere. In light of the new data and perspective, some previous studies of force–velocity relations of muscle are revisited to further our understanding of muscle mechanics and the underlying biochemical events, specifically how extracellular and intracellular environment, protein isoform expression, and posttranslational modification of contractile and regulatory proteins change the interaction between myosin and actin that in turn alter muscle force, shortening velocity, and the relationship between them.
Group radicals and strongly compact cardinals
Authors: Bagaria Joan , Magidor Menachem
Published: November 2013

We answer some natural questions about group radicals and torsion classes, which involve the existence of measurable cardinals, by constructing, relative to the existence of a supercompact cardinal, a model of ZFC in which the first

ω
1

\omega _1

-strongly compact cardinal is singular.
Delta-structures on mapping class groups and braid groups
Authors: Berrick A. , Hanbury E. , Wu J.
Published: November 2013

We describe a Delta-group structure on the mapping class groups of surfaces, and show that it is compatible with the Delta-group structures of the braid groups of surfaces given by Berrick-Cohen-Wong-Wu. We then prove an isomorphism theorem relating these two Delta-groups. This is the first of a pair of papers on this topic.