bluuebunny/crossref_metadata_2025 huggingface dataset:
Content Analysis of 4 Fear of Falling Rating Scales by Linking to the International Classification of Functioning, Disability and Health
Authors: Bladh Stina , Nilsson Maria H. , Carlsson Gunilla , Lexell Jan
Published: March 2013

Objective

To gain a deeper understanding of the content of 4 fear of falling (FOF) rating scales by linking them to the International Classification of Functioning, Disability and Health (ICF).

Design

Linking study according to the ICF linking rules.

Setting

Not applicable.

Patients

Not applicable.

Methods

The rating scales were the Falls Efficacy Scale–International (FES‐I), the Swedish version of the Falls Efficacy Scale (FES[S]), the Activities‐specific Balance Confidence Scale (ABC), and the modified Survey of Activities and Fear of Falling in the Elderly (SAFFE). The process followed the established and updated linking rules. Three linkers independently identified all meaningful concepts in the rating scales and linked them to the most precise ICF categories. The linkers then discussed their results to reach consensus. If consensus was not attained, the linkers pursued the discussions with a fourth person to reach consensus.

Main outcome measurements

Not applicable.

Results

Most meaningful concepts from the overall questions were linked to the ICF component of body functions. Of the 62 items, all but one meaningful concept were linked to the component of activities and participation. All 4 rating scales covered the chapters of mobility and domestic life and had most linkages to the mobility chapter.

Conclusions

The linking process revealed similarities and differences between the 4 FOF rating scales, as well as methodologic challenges in linking instruments to the ICF. By providing a content description that allows for a direct comparison of the rating scales, the results may be helpful when choosing an appropriate rating scale assessing FOF in clinical practice and research. A further head‐to‐head comparison through psychometric analyses is required to recommend appropriate FOF rating scales. Studies are also needed to investigate how the overall question and response categories of a rating scale affect respondents' answers.
Dynamical effect of the total strain induced by the coherent motion on local isotropy in a wake
Authors: Thiesset F. , Danaila L. , Antonia R. A.
Published: March 2013

We assess the extent to which local isotropy (LI) holds in a wake flow for different initial conditions, which may be geometrical (the shape of the bluff body which creates the wake) and hydrodynamical (the Reynolds number), as a function of the dynamical effects of the large-scale forcing (the mean strain, $ \overline{S} $, combined with the strain induced by the coherent motion, $\tilde {S} $). LI is appraised through either classical kinematic tests or phenomenological approaches. In this respect, we reanalyse existing LI criteria and formulate a new isotropy criterion based on the ratio between the turbulence strain intensity and the total strain ($ \overline{S} + \tilde {S} $). These criteria involve either time-averaged or phase-averaged quantities, thus providing a deeper insight into the dynamical aspect of these flows. They are tested using hot wire data in the intermediate wake of five types of obstacles (a circular cylinder, a square cylinder, a screen cylinder, a normal plate and a screen strip). We show that in the presence of an organized motion, isotropy is not an adequate assumption for the large scales but may be satisfied over a range of scales extending from the smallest dissipative scale up to a scale which depends on the total strain rate that characterizes the flow. The local value of this scale depends on the particular nature of the wake and the phase of the coherent motion. The square cylinder wake is the closest to isotropy whereas the least locally isotropic flow is the screen strip wake. For locations away from the axis, the study is restricted to the circular cylinder only and reveals that LI holds at scales smaller than those that apply at the wake centreline. Arguments based on self-similarity show that in the far wake, the strength of the coherent motion decays at the same rate as that of the turbulent motion. This implies the persistence of the same degree of anisotropy far downstream, independently of the scale at which anisotropy is tested.
Lysiphlebus orientalis (Hymenoptera, Braconidae), a new invasive aphid parasitoid in Europe – evidence from molecular markers
Authors: Petrović Andjeljko , Mitrović Milana , Starý Petr , Petrović-Obradović Olivera , Žikić Vladimir , Tomanović Željko , Vorburger Christoph
Published: March 2013

We report the occurrence of Lysiphlebus orientalis in Serbia, an aphid parasitoid from the Far East that is new to Europe and has the potential to become invasive. Our finding based on morphological characters is confirmed by analyses of mitochondrial cytochrome oxidase subunit I sequences. An increase in number and an expansion of the host range were observed during field studies over the past two years, and it is determined that the current host range encompasses nine aphid hosts on 12 different host plants, forming 13 tri-trophic associations. A host range determined for European populations of L. orientalis appears wider compared with that in its Far Eastern native habitats where Aphis glycines Mats. is the sole known host. Moreover, it overlaps considerably with the host ranges of European parasitoids that play an important role in the natural control of pest aphids.
Photius Before His Patriarchate
Authors: TREADGOLD WARREN
Published: March 2013

Photius (patriarch of Constantinople 858–67, 877–86) was born c. 813. His father Sergius,
a wealthy official, was exiled along with Photius for opposing Iconoclasm, evidently in 833.
During this exile, which lasted until 842, Photius read voraciously. Later, probably in 845,
he catalogued his reading in his Bibliotheca. Yet Photius composed neither the Bibliotheca nor his
other pre-858 work as formal scholarly literature, for which the contemporary audience was
exiguous. Indeed he found no satisfactory use for his talents as the leading scholar of his time until
he was rewarded for his learning with the patriarchate.
Volume Dynamics and Multimarket Trading
Authors: Halling Michael , Moulton Pamela C. , Panayides Marios
Published: March 2013

The trading of shares of the same firm in multiple markets has become common over the last 30 years, but there is little empirical evidence on the extent to which investors actively exploit multimarket environments. We introduce a volume-based measure of multimarket trading to address this question. Analyzing a large set of cross-listed firms, we find higher multimarket trading among markets with similar designs and strong enforcement of insider trading laws and for firms with higher institutional ownership. These findings are important for firms evaluating the benefits of cross listing and for markets competing for order flow.
Declarative and procedural memory as individual differences in second language acquisition
Authors: MORGAN-SHORT KARA , FARETTA-STUTENBERG MANDY , BRILL-SCHUETZ KATHERINE A. , CARPENTER HELEN , WONG PATRICK C. M.
Published: March 2013

This study examined how individual differences in cognitive abilities account for variance in the attainment level of adult second language (L2) syntactic development. Participants completed assessments of declarative and procedural learning abilities. They subsequently learned an artificial L2 under implicit training conditions and received extended comprehension and production practice using the L2. Syntactic development was assessed at both early and late stages of acquisition. Results indicated positive relationships between declarative learning ability and syntactic development at early stages of acquisition and between procedural learning ability and development at later stages of acquisition. Individual differences in these memory abilities accounted for a large amount of variance at both stages of development. The findings are consistent with theoretical perspectives of L2 that posit different roles for these memory systems at different stages of development, and suggest that declarative and procedural memory learning abilities may predict L2 grammatical development, at least for implicitly trained learners.
On the nature of verb–noun dissociations in bilectal SLI: A psycholinguistic perspective from Greek
Authors: KAMBANAROS MARIA , GROHMANN KLEANTHES K. , MICHAELIDES MICHALIS , THEODOROU ELENI
Published: March 2013

We report on object and action picture-naming accuracy in two groups of bilectal speakers in Cyprus, children with typical language development (TLD) and children with specific language impairment (SLI). Object names were overall better retrieved than action names by both groups. Given that comprehension for action names was relatively intact for all children, this finding is taken to be the result of a breakdown at the interface of the semantic lexicon and phonological representations, or access to them. The results complement similar research on English, a minimally inflected language in contrast to Greek. Overall, cross-linguistic word class effects provide strong evidence for the hypothesis that grammatical category is an organizing principle shared across languages. Finally, our results suggest that bilectal children with SLI present with general lexical delay rather than a deficit in verb naming per se.
Number of manic episodes is associated with elevated DNA oxidation in bipolar I disorder
Authors: Soeiro-de-Souza Márcio Gerhardt , Andreazza Ana C. , Carvalho Andre F. , Machado-Vieira Rodrigo , Young L. Trevor , Moreno Ricardo Alberto
Published: March 2013

Bipolar disorder (BD) is a major public health problem characterized by progressive functional impairment. A number of clinical variables have been associated with progression of the disease, most notably number of affective episodes and presence of psychotic symptoms, both of which correlate with greater cognitive impairment, lower response rates for lithium, and possibly lower levels of neurotrophic factors. Oxidative damage to cytosine and guanosine (8-OHdG) has been described as a modulator of DNA methylation, but the extent of DNA oxidative damage involvement in BD remains unclear. The aim of this study was to evaluate the extent of DNA oxidative damage to 8-OHdG and 5-methylcytosine (5-HMec), as well as global methylation (5-Mec), in BD patients and healthy controls. Potential association with clinical variables was also investigated. DNA levels of 8-OHdG, 5-HMec and 5-Mec were measured in 50 BD type I patients and 50 healthy controls. DNA 8-OHdG levels were higher in BD patients compared to healthy controls and found to be positively influenced by number of previous manic episodes. BD subjects had lower levels of 5-HMec compared to controls, whereas this measure was not influenced by the clinical features of BD. Number of manic episodes was correlated with higher levels of 8-OHdG, but not of 5-Mec or 5-HMec. Lower demethylation activity (5-HMec) but no difference in global 5-Mec levels was observed in BD. This finding suggests that oxidative damage to 8-OHdG might be a potential marker of disease progression, although further prospective cross-sectional studies to confirm neuroprogression in BD are warranted.
One-step synthesis of carbon-supported foam-like platinum with enhanced activity and durability
Authors: Li Shushuang , Li Huanqiao , Zhang Yansheng , Garcia Robert M. , Li Jia , Xie Yan , Yin Jie , Li Mingrun , Wang Junhu , Shelnutt John A. , Zhang Tao , Song Yujiang
Published: March 2013

Carbon black localized in-between liposomal bi-layers provides a unique supporting–templating bifunctional reaction environment that led to one-step synthesis of shaped Pt foam/C with enhanced activity and durability for oxygen reduction.
Desensitised Kalman filtering
Authors: Karlgaard Christopher D. , Shen Haijun
Published: March 2013

This study discusses the development of a desensitised optimal filtering technique for systems subject to plant and measurement model parameter uncertainties. Desensitised state estimates are obtained by minimising a cost function consisting of the posterior covariance matrix trace penalised by a weighted norm of the state estimate error sensitivities. The resulting filter is non‐minimum variance but exhibits reduced sensitivity to deviations in the assumed plant model parameters. Solutions are obtained for discrete, continuous and mixed continuous‐discrete non‐linear systems using an extended Kalman filter formulation. An example problem involving orbit determination with parameter uncertainty is provided to illustrate the effectiveness of the proposed filtering technique.
Modelling of radiative divertor operation towards detachment in experimental advanced superconducting tokamak
Authors: Chen YiPing , Wang F. Q. , Zha X. J. , Hu L. Q. , Guo H. Y. , Wu Z. W. , Zhang X. D. , Wan B. N. , Li J. G.
Published: March 2013

In order to actively control power load on the divertor target plates and study the effect of radiative divertor on plasma parameters in divertor plasmas and heat fluxes to the targets, dedicated experiments with Ar impurity seeding have been performed on experimental advanced superconducting tokamak in typical L-mode discharge with single null divertor configuration, ohmic heating power of 0.5 MW, and lower hybrid wave heating power of 1.0 MW. Ar is puffed into the divertor plasma at the outer target plate near the separatrix strike point with the puffing rate 1.26×1020 s−1. The radiative divertor is formed during the Ar puffing. The SOL/divertor plasma in the L-mode discharge with radiative divertor has been modelled by using SOLPS5.2 code package [V. Rozhansky et al., Nucl. Fusion 49, 025007 (2009)]. The modelling shows the cooling of the divertor plasma due to Ar seeding and is compared with the experimental measurement. The changes of peak electron temperature and heat fluxes at the targets with the shot time from the modelling results are similar to the experimental measurement before and during the Ar impurity seeding, but there is a major difference in time scales when Ar affects the plasma in between experiment and modelling.
Temporal disconnectivity of the energy landscape in glassy systems
Authors: Lempesis Nikolaos , Boulougouris Georgios C. , Theodorou Doros N.
Published: March 2013

An alternative graphical representation of the potential energy landscape (PEL) has been developed and applied to a binary Lennard-Jones glassy system, providing insight into the unique topology of the system's potential energy hypersurface. With the help of this representation one is able to monitor the different explored basins of the PEL, as well as how – and mainly when – subsets of basins communicate with each other via transitions in such a way that details of the prior temporal history have been erased, i.e., local equilibration between the basins in each subset has been achieved. In this way, apart from detailed information about the structure of the PEL, the system's temporal evolution on the PEL is described. In order to gather all necessary information about the identities of two or more basins that are connected with each other, we consider two different approaches. The first one is based on consideration of the time needed for two basins to mutually equilibrate their populations according to the transition rate between them, in the absence of any effect induced by the rest of the landscape. The second approach is based on an analytical solution of the master equation that explicitly takes into account the entire explored landscape. It is shown that both approaches lead to the same result concerning the topology of the PEL and dynamical evolution on it. Moreover, a “temporal disconnectivity graph” is introduced to represent a lumped system stemming from the initial one. The lumped system is obtained via a specially designed algorithm [N. Lempesis, D. G. Tsalikis, G. C. Boulougouris, and D. N. Theodorou, J. Chem. Phys. 135, 204507 (2011)10.1063/1.3663207]. The temporal disconnectivity graph provides useful information about both the lumped and the initial systems, including the definition of “metabasins” as collections of basins that communicate with each other via transitions that are fast relative to the observation time. Finally, the two examined approaches are compared to an “on the fly” molecular dynamics-based algorithm [D. G. Tsalikis, N. Lempesis, G. C. Boulougouris, and D. N. Theodorou, J. Chem. Theory Comput. 6, 1307 (2010)10.1021/ct9004245].
All-time dynamics of continuous-time random walks on complex networks
Authors: Teimouri Hamid , Kolomeisky Anatoly B.
Published: March 2013

The concept of continuous-time random walks (CTRW) is a generalization of ordinary random walk models, and it is a powerful tool for investigating a broad spectrum of phenomena in natural, engineering, social, and economic sciences. Recently, several theoretical approaches have been developed that allowed to analyze explicitly dynamics of CTRW at all times, which is critically important for understanding mechanisms of underlying phenomena. However, theoretical analysis has been done mostly for systems with a simple geometry. Here we extend the original method based on generalized master equations to analyze all-time dynamics of CTRW models on complex networks. Specific calculations are performed for models on lattices with branches and for models on coupled parallel-chain lattices. Exact expressions for velocities and dispersions are obtained. Generalized fluctuations theorems for CTRW models on complex networks are discussed.
Mathematical analysis of recent analytical approximations to the collapse of an empty spherical bubble
Authors: Amore Paolo , Fernández Francisco M.
Published: March 2013

We analyze the Rayleigh equation for the collapse of an empty bubble and provide an explanation for some recent analytical approximations to the model. We derive the form of the singularity at the second boundary point and discuss the convergence of the approximants. We also give a rigorous proof of the asymptotic behavior of the coefficients of the power series that are the basis for the approximate expressions.
Calculation of the transport properties of a dilute gas consisting of Lennard-Jones chains
Authors: Hellmann Robert , Riesco Nicolas , Vesovic Velisa
Published: March 2013

The transport properties in the dilute gas limit have been calculated by the classical-trajectory method for a gas consisting of chain-like molecules. The molecules were modelled as rigid chains consisting of spherical segments that interact through a combination of site-site Lennard-Jones 12-6 potentials. Results are reported for shear viscosity, self-diffusion, and thermal conductivity for chains consisting of 1, 2, 3, 4, 5, 6, 7, 8, 10, 13, and 16 segments in the reduced temperature range of 0.3 − 50. The results indicate that the transport properties increase with temperature and decrease with chain length. At high temperatures the dependence of the transport properties is governed effectively by the repulsive part of the potential. No simple scaling with chain length has been observed. The higher order correction factors are larger than observed for real molecules so far, reaching asymptotic values of 1.019 − 1.033 and 1.060 − 1.072 for viscosity and thermal conductivity, respectively. The dominant contribution comes from the angular momentum coupling. The agreement with molecular dynamics calculations for viscosity is within the estimated accuracy of the two methods for shorter chains. However, for longer chains differences of up to 7% are observed.
Influence of gold coating and interplate voltage on the performance of chevron micro-channel plates for temporally and spatially resolved single particle detection
Authors: Hoendervanger A. L. , Clément D. , Aspect A. , Westbrook C. I. , Dowek D. , Picard Y. J. , Boiron D.
Published: March 2013

We present a study of two different sets of Micro-Channel Plates used for time and space resolved single particle detection. We investigate the effects of the gold coating and that of introducing an interplate voltage between the spatially separated plates. We find that the gold coating increases the count rate of the detector and the pulse amplitude as previously reported for non-spatially resolved setups. The interplate voltage also increases count rates. In addition, we find that a non-zero interplate voltage improves the spatial accuracy in determining the arrival position of incoming single particles (by ∼20%) while the gold coating has a negative effect (by ∼30%).
Development of a polarization resolved spectroscopic diagnostic for measurements of the vector magnetic field in the Caltech coaxial magnetized plasma jet experiment
Authors: Shikama T. , Bellan P. M.
Published: March 2013

In the Caltech coaxial magnetized plasma jet experiment, fundamental studies are carried out relevant to spheromak formation, astrophysical jet formation/propagation, solar coronal physics, and the general behavior of twisted magnetic flux tubes that intercept a boundary. In order to measure the spatial profile of the magnetic field vector for understanding the underlying physics governing the dynamical behavior, a non-perturbing visible emission spectroscopic method is implemented to observe the Zeeman splitting in emission spectra. We have designed and constructed a polarization-resolving optical system that can simultaneously detect the left- and right-circularly polarized emission. The system is applied to singly ionized nitrogen spectral lines. The magnetic field strength is measured with a precision of about ±13 mT. The radial profiles of the azimuthal and axial vector magnetic field components are resolved by using an inversion method.
Solvation effects on like-charge attraction
Authors: Ghanbarian Shahzad , Rottler Jörg
Published: March 2013

We present results of molecular dynamics simulations of the electrostatic interaction between two parallel charged rods in the presence of divalent counterions. Such polyelectrolytes have been considered as a simple model for understanding electrostatic interactions in highly charged biomolecules such as DNA. Since there are correlations between the free charge carriers, the phenomenon of like charge attraction appears for specific parameters. We explore the role of solvation effects and the resulting deviations from Coulomb's law on the nanoscale on this peculiar phenomenon. The behavior of the force between the charged rods in a simulation with atomistic representation of water molecules is completely different from a model in which water is modeled as a continuum dielectric. By calculating counterion-rodion pair correlation functions, we find that the presence of water molecules changes the structure of the counterion cloud and results in both qualitative and quantitative changes of the force between highly charged polyelectrolytes.
Epitaxial graphene morphologies probed by weak (anti)-localization
Authors: Mahmood A. , Naud C. , Bouvier C. , Hiebel F. , Mallet P. , Veuillen J.-Y. , Lévy L. P. , Chaussende D. , Ouisse T.
Published: March 2013

We show how the weak field magneto-conductance can be used as a tool to characterize epitaxial graphene samples grown from the C or the Si face of silicon carbide, with mobilities ranging from 120 to 12 000 cm2/(V·s). Depending on the growth conditions, we observe anti-localization and/or localization, which can be understood in term of weak-localization related to quantum interferences. The inferred characteristic diffusion lengths are in agreement with the scanning tunneling microscopy and the theoretical model which describe the “pure” mono-layer and bilayer of graphene [MacCann et al., Phys. Rev. Lett. 97, 146805 (2006)].
Semiconductor laser monolithically pumped with a light emitting diode operating in the thermoelectrophotonic regime
Authors: Liu X. , Zhao G. , Zhang Y. , Deppe D. G.
Published: March 2013

Data are presented on a monolithic chip that integrates a quantum well semiconductor laser with a high efficiency light emitting diode (LED), with the LED used to optically pump the laser. The LED operates in the thermoelectrophotonic regime that can produce heat absorption, offering the possibility of heat pump action. The internal optical pumping also offers the possibility of very low internal loss in the laser and the prospect of reaching greater than unity power conversion efficiency in the laser chip. The integrated laser chip is operated and tested under continuous-wave room temperature operation.
Rotating copper plasmoid in external magnetic field
Authors: Pandey Pramod K. , Thareja Raj K.
Published: March 2013

Effect of nonuniform magnetic field on the expanding copper plasmoid in helium and argon gases using optical emission spectroscopy and fast imaging is presented. We report a peculiar oscillatory rotation of plasmoid in magnetic field and argon ambient. The temporal variation and appearance of the dip in the electron temperature show a direct evidence of the threading and expulsion of the magnetic field lines from the plasmoid. Rayleigh Taylor instability produced at the interface separating magnetic field and plasma is discussed.
The evolution of the magnetic phases of Sb-doped Mn5Sn3 compounds
Authors: Xu J. H. , Xia Y. H. , Yang W. Y. , Du H. L. , Yang J. B. , Wang C. S. , Han J. Z. , Liu S. Q. , Yang Y. C.
Published: March 2013

The structural and magnetic properties of Mn5(Sn1−xSbx)3 compounds (x = 0-0.4) were investigated by means of X-ray diffraction and magnetization measurements. All samples crystallize in Ni2In-type structure (P63/mmc) with the lattice parameters changing anisotropically with the increase of Sb concentration. Sb doping leads to the merging of the ferrimagnetic transition temperature Tc and the re-entrant spin-glass transition temperature Tf, indicating a direct transition from spin-glass state to paramagnetic state. The M(H) curve at 5 K evolves with x from a soft-magnet type to a linear-like shape. We proposed a basic explanation for the evolution of the magnetic properties in terms of crystal structure and magnetic interactions, which can be applied to other related compounds.
Theoretical investigation of InAs/GaSb type-II pin superlattice infrared detector in the mid wavelength infrared range
Authors: Kaya U. , Hostut M. , Kilic A. , Sakiroglu S. , Sokmen I. , Ergun Y. , Aydinli A.
Published: March 2013

In this study, we present the theoretical investigation of type-II InAs/GaSb superlattice p-i-n detector. Kronig-Penney and envelope function approximation is used to calculate band gap energy and superlattice minibands. Variational method is also used to calculate exciton binding energies. Our results show that carriers overlap increases at GaSb/InAs interface on the higher energy side while it decreases at InAs/GaSb interface on the lower energy side with increasing reverse bias due to shifting the hole wavefunction toward to the GaSb/InAs interface decisively. Binding energies increase with increasing electric field due to overall overlap of electron and hole wave functions at the both interfaces in contrast with type I superlattices. This predicts that optical absorption is enhanced with increasing electric field.
Total transmission and total reflection of electromagnetic waves by anisotropic epsilon-near-zero metamaterials embedded with dielectric defects
Authors: Zhang Kuang , Fu Jiahui , Xiao Li-Yi , Wu Qun , Li Le-Wei
Published: March 2013

In this paper, the transmission of the electromagnetic waves in the waveguide filled with the anisotropic epsilon-near-zero (ENZ) metamaterials with dielectric cylindrical defects embedded is investigated. The anisotropy is taken into consideration, and the sandwich structure is put forward to achieve total transmission and total reflection. Despite of the anisotropy and the impedance mismatch compared with the matched impedance zero-index metamaterials, both the analytical and the numerical results show that the total reflection and the total transmission can be achieved. Furthermore, some factors that own potential effects on the transmission of the electromagnetic waves are also discussed, and it is interesting to find that the radius of the embedded dielectric cylindrical defect could greatly affect the bandwidth of total transmission and total reflection. By removing the dependence on isotropy and impedance matching, our work can facilitate the applications of the ENZ metamaterials in the waveguide.
The reverse mode of the photo activated charge domain in high field biased semi-insulating GaAs
Authors: Qu Guanghui , Shi Wei
Published: March 2013

The nonlinear accumulation of the photogenerated electrons in high field biased SI-GaAs has been defined as photo activated charge domain (PACD). The transient transport dynamics of the PACD is investigated. The result shows that the PACD, working as a reverse gun dipole domain when biased electric field much higher than 4 kV/cm, and the reverse mode of the PACD could dominate the electric field shielding by its main electric field ultrafast and exponential rising against the bias field. Such mechanisms could play an important role in GaAs THz antenna, GaAs photoconductive semiconductor switch, and the other ultrafast GaAs devices.
Effect of barrier layers on electroluminescence from Si/SiOxNy multilayer structures
Authors: Wang Xiang , Huang Rui , Song Chao , Guo Yanqing , Song Jie
Published: March 2013

We report the effect of barrier layer on the electroluminescence from Si/SiOxNy multilayer structures, where the SiOxNy barrier layers were modulated by varying the oxygen/nitride ratio. It is found that the electroluminescence efficiency is significantly enhanced by more than one order of magnitude through controlling the oxygen/nitride ratio. The high emission efficiency is ascribed to the equivalent carrier injections that increase the carrier recombination probability. In addition, the strong confinement of carriers as a result of the increase of the barrier height also plays a role in the increasing radiative recombination efficiency.
Effect of longitudinal degree of freedom of magnetic moment in body-centered-cubic iron
Authors: Yin Junqi , Eisenbach Markus , Nicholson Don M. , Rusanu Aurelian
Published: March 2013

First principle calculations are performed to study the longitudinal degree of freedom of the magnetic moment in BCC iron. A model of the Heisenberg type of exchange interaction is proposed, which couples the spin and lattice degrees of freedom. Monte Carlo simulations are then applied to study the effect of thermal displacements on the magnetic phase transition in BCC Iron. The reason for the surprising success of fixed lattice Heisenberg models is explained.
Formation of double ring patterns on Co2MnSi Heusler alloy thin film by anodic oxidation under scanning probe microscope
Authors: Toutam Vijaykumar , Pandey Himanshu , Singh Sandeep , Budhani R. C.
Published: March 2013

Double ring formation on Co2MnSi (CMS) films is observed at electrical breakdown voltage during local anodic oxidation (LAO) using atomic force microscope (AFM). Corona effect and segregation of cobalt in the vicinity of the rings is studied using magnetic force microscopy and energy dispersive spectroscopy. Double ring formation is attributed to the interaction of ablated material with the induced magnetic field during LAO. Steepness of forward bias transport characteristics from the unperturbed region of the CMS film suggest a non equilibrium spin contribution. Such mesoscopic textures in magnetic films by AFM tip can be potentially used for memory storage applications.
Multiple and colorful cone-shaped lasing induced by band-coupling in a 1D dual-periodic photonic crystal
Authors: Ying Cui-Feng , Zhou Wen-Yuan , Li Yi , Ye Qing , Yang Na , Tian Jian-Guo
Published: March 2013

We demonstrate multiple and colorful cone-shaped lasing from dual-periodic photonic crystal, indicating that coupling occurs between the photonic bands in a photonic crystal laser system. We propose a band-coupling model to estimate lasing wavelengths and emission-cone angles, which match well those from experimental observations from cone-shaped lasing. Band coupling may yield a high optical-conversion efficiency in photonic crystal laser systems, and be of interest in quantum optics communication.
Activation energy for alkaline-earth ion transport in low alkali aluminoborosilicate glasses
Authors: Dash Priyanka , Furman Eugene , Pantano Carlo G. , Lanagan Michael T.
Published: March 2013

Activation energies (Ea) for ionic conduction in low-alkali boroaluminosilicate glasses due to alkaline-earth (Ba, Ca) and alkali (Na) ion transport have been estimated using thermally stimulated depolarization current (TSDC) and AC impedance spectroscopy techniques. The TSDC plot showed distinct relaxation peaks which shifted to higher temperatures with increasing ramp rates, and the dielectric dispersion plot showed individual low frequency relaxation peaks indicating space charge polarization due to transport of cations with different Ea (0.93, 1.83, and 3.5 eV for Na, Ba, and Ca, respectively). The higher value of Ea for Ca transport is attributed to mixed alkaline earth effect.
Violet-blue photoluminescence from Si nanoparticles with zinc-blende structure synthesized by laser ablation in liquids
Authors: Liu P. , Liang Y. , Li H. B. , Xiao J. , He T. , Yang G. W.
Published: March 2013

Violet-blue luminescence from Si nanostructures has been widely investigated, because of its potential use in optoelectronic and bioimaging devices. However, the emission mechanism in multiform Si nanomaterials remains unclear. In this contribution, Si nanocrystals (NCs) with zincblende structure and visible violet-blue emission are prepared by electric field assisted laser ablation in liquids. While subsequent annealing of the Si NCs weakens their blue emission dramatically. We investigate the origin of the violet-blue emission by monitoring crystal structure transitions and photoluminescence during different treatments of the Si NCs. The results indicate that the violet-blue emission cannot simply be ascribed to quantum confinement effects or the presence of general surface states on the Si NCs. Instead, we propose that excitons are formed within the Si NCs by direct transitions at Γ or X points, which can be induced during the formation of the zincblende structure, and are a most possible origin of the violet-blue luminescence. Furthermore, defects in the metastable Si NCs are also expected to play an important role in violet-blue emission. This study not only gives clear and general insight into the physical origins of violet-blue emission from Si NCs, it also provides useful information for designing optoelectronic devices based on Si NCs.
STUDIES OF NGC 6720 WITH CALIBRATED HST/WFC3 EMISSION-LINE FILTER IMAGES. II. PHYSICAL CONDITIONS*
,†
Authors: O'Dell C. R. , Ferland G. J. , Henney W. J. , Peimbert M.
Published: March 2013

We have performed a detailed analysis of the electron temperature and density in the Ring Nebula using the calibrated Hubble Space Telescope WFC3 images described in the preceding paper. The electron temperature (T
e) determined from [N ii] and [O iii] rises slightly and monotonically toward the central star. The observed equivalent width (EW) in the central region indicates that T
e rises as high as 13,000 K. In contrast, the low EWs in the outer regions are largely due to scattered diffuse Galactic radiation by dust. The images allowed determination of unprecedented small-scale variations in T
e. These variations indicate that the mean square area temperature fluctuations are significantly higher than expected from simple photoionization. The power producing these fluctuations occurs at scales of less than 3.5×1015 cm. This scale length provides a strong restriction on the mechanism causing the large t
2 values observed.
PINK1 and Parkin complementarily protect dopaminergic neurons in vertebrates
Authors: Matsui Hideaki , Gavinio Roberto , Asano Takeshi , Uemura Norihito , Ito Hidefumi , Taniguchi Yoshihito , Kobayashi Yoshito , Maki Takakuni , Shen Jie , Takeda Shunichi , Uemura Kengo , Yamakado Hodaka , Takahashi Ryosuke
Published: March 2013

Parkinson's disease (PD) is a common neurodegenerative disorder characterized by selective dopaminergic cell loss in the substantia nigra, but its pathogenesis remains unclear. The recessively inherited familial PD genes PARK2 and PARK6 have been attributed to mutations in the Parkin and PTEN-induced kinase 1 (PINK1) genes, respectively. Recent reports suggest that PINK1 works upstream of Parkin in the same pathway to regulate mitochondrial dynamics and/or conduct autophagic clearance of damaged mitochondria. This phenomenon is preserved from Drosophila to human cell lines but has not been demonstrated in a vertebrate animal model in vivo. Here, we developed a medaka fish (Oryzias latipes) model that is deficient in Pink1 and Parkin. We found that despite the lack of a conspicuous phenotype in single mutants for Pink1 or Parkin, medaka that are deficient in both genes developed phenotypes similar to that of human PD: late-onset locomotor dysfunction, a decrease in dopamine levels and a selective degeneration of dopaminergic neurons. Further analysis also revealed defects in mitochondrial enzymatic activity as well as cell death. Consistently, PINK1 and Parkin double-deficient MEF showed a further decrease in mitochondrial membrane potential and mitochondrial complex I activity as well as apoptosis compared with single-deficient MEF. Interestingly, these mitochondrial abnormalities in Parkin-deficient MEF were compensated by exogenous PINK1, but not by disease-related mutants. These results suggest that PINK1 and Parkin work in a complementary way to protect dopaminergic neurons by maintaining mitochondrial function in vertebrates.
Bringing teaching to life
Authors: Brandon‐Jones Alistair , Piercy Niall , Slack Nigel
Published: March 2013

Purpose

The aim of this review and of the papers in this special issue is to critically examine different approaches to teaching operations management (OM) in order to provoke and stimulate educators within the discipline.

Design/methodology/approach

The papers within this special issue include empirical assessments of a problem‐based learning enterprise resource planning (ERP) simulation; a computer‐based learning tool for material requirements planning (MRP); a simulation of assembly operations; an operations strategy innovation game; an extension of the production dice game; an experiential teaching method in different class settings; and problem‐based assessment methods in OM. A variety of data are used to support these empirical studies, including survey, interview, and observational data.

Findings

The papers within the special issue support the argument that OM is well‐suited to more applied methods of teaching focusing on the application of subject knowledge to real‐life situations through a variety of techniques.

Practical implications

It is hoped that this review and the papers within this special issue act to stimulate educators to re‐evaluate their approaches to teaching OM and encourage them to consider adopting experiential teaching methods, business simulations, role‐plays, group exercises, live cases, and virtual learning environments, instead of, or in addition to, the more conventional lectures that typically dominate many OM modules around the world.

Originality/value

A special issue on teaching OM appears timely given the significant changes to both the university landscape and to the nature of the discipline that we have witnessed over the last quarter of a century.
Interactive learning in operations management higher education
Authors: Arenas‐Márquez Francisco J. , Machuca José A.D. , Medina‐López Carmen
Published: March 2013

Purpose

The purpose of this paper is to describe a computer‐assisted learning experience in operations management (OM) higher education that entailed the development of interactive learning software, its evaluation in an experimental environment and the formal analysis of the teaching method's influence on student perceptions.

Design/methodology/approach

The software design follows the constructivist focus based on widely‐accepted educational technology principles. Objective tests of knowledge and subjective appraisal of the learning process were used in the experiment to compare two educational scenarios (computer‐assisted learning and on‐site class). Students' perceptions of the software's technical and teaching features are also analyzed.

Findings

The study shows that the teaching method can significantly affect students' perceptions of the learning process. The findings also confirm the pedagogical effectiveness of the software that was designed and that information communication technologies (ICT)‐based methods are an alternative to traditional methods used in OM education.

Research limitations/implications

The experiment involved strict control over various potential threats to validity. From a statistical point‐of‐view, the conclusions can only be generalized in the population analyzed. Nevertheless, the features of the software and the student profile allow the main conclusions to be generalized to other OM environments.

Practical implications

The use and evaluation of interactive software in OM educational environments are reflected on, with emphasis on the influence that the teaching methodology has on students' attitudes to the learning process. It is of interest for researchers interested in improving teaching through the use of ICT.

Originality/value

There are very few studies on interactive self‐learning software for OM and its effects on student perceptions. This paper is a new contribution to this field.
Japanese innovation processes
Authors: Ota Masaharu , Hazama Yohsuke , Samson Danny
Published: March 2013

Purpose

The aim of this study is to propose and test a model of innovation process management and to clarify the managerial strategies required to achieve it in Japanese enterprises.

Design/methodology/approach

The authors conducted empirical tests of the model using the data from the questionnaire surveys of Japanese companies, and an illustrative case study.

Findings

It was found that there was a high likelihood that the IP of Japanese companies thought to have had success with innovation matched the proposed model. The support for the model from the Japanese data is sufficiently strong so as to suggest that certain managerial factors should generally be implemented in order to succeed with innovation. The authors then conducted a case study on a notably prominent Japanese company, Toyota, interviewing senior executives both in Japan and Australia. This was done in order to further verify and enrich the findings of the model development and the empirical survey study. The authors found specific practices and capabilities that were statistically significant in Japan's manufacturing companies in general, which were also deeply engrained within Toyota in particular. The importance of structured process in Toyota in particular and generally in the Japanese manufacturing sector was confirmed, comprising scanning, idea occurrence, strategy formulation, resource procurement, implementation and value creation.

Originality/value

This study is one of few that shows the particular approach used in Japanese manufacturing companies. That systematic approach led Japanese manufacturing companies to be at the forefront of innovation for three decades from 1975, and able to successfully expand internationally.
Negotiating future careers
Authors: Fossland Trine
Published: March 2013

Purpose

The management literature concludes that there is an increasing need for skilled migrants in Europe. A fresh comparative OECD study highlights Norway as one of the successful countries in terms of attracting highly qualified migrants. Regardless of this picture, many skilled migrants do not get their education recognised and face great challenges in their career development. The purpose of this paper is to contribute to this under‐researched field in management studies by focusing on skilled migrants’ careers development as a question of human capital and negotiations at a relational level.

Design/methodology/approach

This study draws on interviews with recruitment agencies and life‐story interviews with high‐skilled immigrants, attending the programme “Global future – mobilisation of talented immigrants with higher education”, initiated by the Confederation of Norwegian Business and Enterprise (NHO) in Norway.

Findings

Recruitment is a multi‐layered and relational process, involving different negotiators, negotiations and inequality regimes. Language skills, gendered expectations, networks, local knowledge and the attitude of employers play an important role in skilled migrants’ careers development and labour market participation.

Originality/value

This paper presents recent literature on highly skilled migration in Norway. By focusing on participants in a new type of recruitment programme for highly skilled migrants in Norway, the findings can give input to both employers and policy makers regarding the nature of integrating highly skilled migrants.
Library consortium: IITA, Ibadan, Nigeria experience
Authors: Comfort Ilesanmi Titilayo
Published: March 2013

Purpose

This paper aims to describe the library consortium experienced at the International Institute of Tropical Agriculture (IITA), Ibadan, Nigeria. Activities involved improving researchers' timely access to resources for research for development.

Design/methodology/approach

The approach taken was a librarian interview and observation of library records.

Findings

The consortium involves agricultural libraries in both developing and developed countries. Using the library software Inmagic database enhances the web‐based centralized online public access catalogue of all the participating institutions, the CGV Library. This enabled access to their comprehensive collections, promoting better library services to agricultural researchers. Hence, it bridges the digital gap between developing and developed countries. They are involved in joint acquisition of electronic journals and timely response to sharing their independent collections through electronic document delivery services.

Practical implications

The paper recommends that Nigerian libraries, especially agricultural research institutes, could emulate the IITA library consortium.

Originality/value

The paper provides recommendations to libraries wishing to form consortia in Nigeria and notes the positive impacts that this would have on national development.
Feasibility study of digital document supply services in Iranian research institutes and academic libraries
Authors: Shabani Ahmad , Tabbakhan Mansoureh , Naderikharaji Fatemeh
Published: March 2013

Purpose

The paper's aim is to study the feasibility of establishing digital document supply services in libraries of research institutes and universities in Isfahan province.

Design/methodology/approach

The research is of a descriptive survey type. The population under study included librarians working in academic and research institute libraries in Isfahan province. The data were collected via a researcher‐made questionnaire using a five‐point Likert scale.

Findings

The study indicates that the feasibility of establishing digital document supply services in academic and research institute libraries in Isfahan province is less than average, which is not desirable.

Originality/value

The paper provides information about the state of document supply services in Iranian academic libraries and research institutes.