bluuebunny/crossref_metadata_2025 huggingface dataset:
Real-space Berry phases: Skyrmion soccer (invited)
Authors: Everschor-Sitte Karin , Sitte Matthias
Published: April 2014

Berry phases occur when a system adiabatically evolves along a closed curve in parameter space. This tutorial-like article focuses on Berry phases accumulated in real space. In particular, we consider the situation where an electron traverses a smooth magnetic structure, while its magnetic moment adjusts to the local magnetization direction. Mapping the adiabatic physics to an effective problem in terms of emergent fields reveals that certain magnetic textures, skyrmions, are tailormade to study these Berry phase effects.
Dispersion relations for slow and fast resistive wall modes within the Haney-Freidberg model
Authors: Lepikhin N. D. , Pustovitov V. D.
Published: April 2014

The dispersion relation for the resistive wall modes (RWMs) is derived by using the trial function for the magnetic perturbation proposed in S. W. Haney and J. P. Freidberg, Phys. Fluids B 1, 1637 (1989). The Haney-Freidberg (HF) approach is additionally based on the expansion in dw/s≪1, where dw is the wall thickness and s is the skin depth. Here, the task is solved without this constraint. The derivation procedure is different too, but the final result is expressed in a similar form with the use of the quantities entering the HF relation. The latter is recovered from our more general relation as an asymptote at dw≪s, which proves the equivalence of the both approaches in this case. In the opposite limit (dw≫s), we obtain the growth rate γ of the RWMs as a function of γHF calculated by the HF prescription. It is shown that γ∝γHF2 and γ≫γHF in this range. The proposed relations give γ for slow and fast RWMs in terms of the integrals calculated by the standard stability codes for toroidal systems with and without a perfectly conducting wall. Also, the links between the considered and existing toroidal and cylindrical models are established with estimates explicitly showing the relevant dependencies.
Plasma density accumulation on a conical surface for diffusion along a diverging magnetic field
Authors: Saha S. K. , Chowdhury S. , Janaki M. S. , Ghosh A. , Hui A. K. , Raychaudhuri S.
Published: April 2014

Two-dimensional (2-D) density and potential measurements have been carried out for plasma diffusing through an aperture in a diverging magnetic field. The radial density profile near the source is peaked on the axis but gradually evolves into a hollow profile away from the source. We observe a slow increase of the peak density along a hollow conical surface and correlate with the 2-D potential measurement reported earlier. It is also shown that the formation of 2-D structures with similar features are observed whenever plasma is allowed to diffuse through a physical aperture in such diverging magnetic field configuration, with or without the presence of electric double layer, i.e., the phenomenon is generic in nature.
Experimental evidences of a large extrinsic spin Hall effect in AuW alloy
Authors: Laczkowski P. , Rojas-Sánchez J.-C. , Savero-Torres W. , Jaffrès H. , Reyren N. , Deranlot C. , Notin L. , Beigné C. , Marty A. , Attané J.-P. , Vila L. , George J.-M. , Fert A.
Published: April 2014

We report an experimental study of a gold-tungsten alloy (7 at. % W concentration in Au host) displaying remarkable properties for spintronics applications using both magneto-transport in lateral spin valve devices and spin-pumping with inverse spin Hall effect experiments. A very large spin Hall angle of about 10% is consistently found using both techniques with the reliable spin diffusion length of 2 nm estimated by the spin sink experiments in the lateral spin valves. With its chemical stability, high resistivity, and small induced damping, this AuW alloy may find applications in the nearest future.
Magnetic cloaking by a paramagnet/superconductor cylindrical tube in the critical state
Authors: Yampolskii S. V. , Genenko Y. A.
Published: April 2014

Cloaking of static magnetic fields by a finite thickness type-II superconductor tube being in the full critical state and surrounded by a coaxial paramagnet shell is studied. On the basis of exact solutions to the Maxwell equations, it is shown that, in addition to previous studies assuming the Meissner state of the superconductor constituent, perfect cloaking is still realizable at fields higher than the field of full flux penetration into the superconductor and for arbitrary geometrical parameters of both constituents. It is also proven that simultaneously the structure is fully undetectable under the cloaking conditions. Different from the case of the Meissner state, the cloaking properties in the application relevant critical state are realized, however, only at a certain field magnitude.
Transport and magnetotransport study of Mg doped ZnO thin films
Authors: Agrawal Arpana , Dar Tanveer A. , Sen Pratima , Phase Deodatta M.
Published: April 2014

We report negative magnetoresistance in pulsed laser deposited single phase ZnO and Mg0.268Zn0.732O films and attribute it to the presence of oxygen interstitials (Oi) and zinc interstitials (Zni) as observed in the X-ray photoelectron spectra of the films. An interesting feature of reduction of negative magnetoresistance at low temperatures and large fields in Mg0.268Zn0.732O film is observed and is explained by taking into account the localized scattering.
Structural and dynamical magnetic response of co-sputtered Co2FeAl heusler alloy thin films grown at different substrate temperatures
Authors: Yadav Anjali , Chaudhary Sujeet
Published: April 2014

The interdependence between the dynamical magnetic response and the microstructural properties such as crystallinity, lateral crystallite size, structural ordering of the co-sputtered polycrystalline Co2FeAl thin films on Si (100) are studied by varying the growth temperature from room temperature (RT) to 600 °C. Frequency (7–11 GHz) dependent in-plane ferromagnetic resonance (FMR) studies were carried out by using co-planar waveguide to estimate Gilbert damping constant (α) and effective saturation magnetization (4πMeff). The improvement in crystallinity, larger crystallite and particle sizes of the films are critical in obtaining films with lower α and higher 4πMeff. Increase in the lattice constant with substrate temperature indicates the improvement in the structural ordering at higher temperatures. Minimum value of α is found to be 0.005 ± 0.0003 for the film deposited at 500 °C, which is comparable to the values reported for epitaxial Co2FeAl films. The value of 4πMeff is found to increase from 1.32 to 1.51 T with the increase in deposition temperature from RT to 500 °C. The study also shows that the root mean square (rms) roughness linearly affects the FMR in-homogenous line broadening and the anisotropy field.
Influence of the structure defects on the magnetic properties of the FePt/Fe bilayer
Authors: Plotnikova E. M. , Trushkin I. I. , Lenkevich D. A. , Kotelnikov A. L. , Cockburn A. , Zvezdin K. A.
Published: April 2014

Thin magnetic multilayered films containing FePt have attracted a lot of attention recently due to their possible usage in ultra-high density magnetic storage. Although structure defects play a dramatic role in the magnetization process and influence magnetic properties in general this dependence have not been studied thoroughly. The main aim of this work was to perform theoretical investigation of the magnetic properties of FePt and Fe/FePt thin films with high coercivity with respect to the structure defects such as anisotropy constant, magnetization saturation, exchange constant fluctuations, and easy axis deviation. For selected defect patterns, the coercive field dependence on layer thicknesses was analysed. Numerical study of the bilayer with hard magnetic layer having the planar anisotropy was carried on using micromagnetic calculations. Values of layers thickness have been found optimal for perspective applications, the dependence of the hysteresis loop shape upon the magnetization process has been shown and analysed.
Direct evidences of filamentary resistive switching in Pt/Nb-doped SrTiO3 junctions
Authors: Yang M. , Ren L. Z. , Wang Y. J. , Yu F. M. , Meng M. , Zhou W. Q. , Wu S. X. , Li S. W.
Published: April 2014

The first concerned question on the fundamental physics of the resistive switching (RS) effect in metal/Nb-doped SrTiO3 junctions is whether the RS does take place at the whole interface or at some local regions of the interface. Even though several investigations provide the clues of the filamentary nature of the RS, direct evidences are still required. Moreover, there is obvious inconsistency between the possible filamentary feature and the observed capacitance-voltage (C-V) hysteresis loops. Here, we report direct evidences of a filamentary RS effect in Pt/Nb-doped SrTiO3 junctions. The virgin Pt/NSTO junctions show an initial RS effect. The current-voltage (I-V) characteristic of the initial RS and the C-V characteristic in the virgin junctions are interpreted by using the theory of metal/semiconductor contacts. The correspondence between the initial RS and the C-V hysteresis loops is also discussed. The most important is that an electroforming process is observed at a large forward voltage, which is a direct indication of the formation of conductive filaments across the Pt/NSTO interface. Following the electroforming, the Pt/NSTO junctions exhibit a filamentary RS effect. The I-V characteristic of the filamentary RS deviates from the theoretical prediction of metal/semiconductor interfaces. However, the C-V characteristic is almost the same as that of the virgin junctions. This demonstrates that the conductive filaments are formed at local regions of the Pt/NSTO interface and a majority of the interface remains invariant. The results clearly show that a filamentary RS effect occurs in the Pt/NSTO junctions and that the observed C-V hysteresis loops are not correlated to the filamentary RS.
Structure, valence, and magnetism of Co-doped ZnO at the coalescence limit (invited)
Authors: Ney A. , Ney V. , Kieschnick M. , Wilhelm F. , Ollefs K. , Rogalev A.
Published: April 2014

Zn0.8Co0.2O epitaxial films have been grown by reactive magnetron sputtering and investigated with regard to the local structural properties, valence, and magnetism using x-ray absorption spectroscopy and both linear as well as magnetic circular dichroism. Samples were found to be phase pure and paramagnetic even at the coalescence of the Co doping and a small magnetic polarization of the Zn can be inferred. The changes of structure, valence, and magnetism upon increasing the oxygen content in the sputter gas are researched as well.
Nitrogen incorporated ultrananocrystalline diamond based field emitter array for a flat-panel x-ray source
Authors: Posada Chrystian M. , Grant Edwin J. , Divan Ralu , Sumant Anirudha V. , Rosenmann Daniel , Stan Liliana , Lee Hyoung K. , Castaño Carlos H.
Published: April 2014

A field emission based flat-panel transmission x-ray source is being developed as an alternative for medical and industrial imaging. A field emitter array (FEA) prototype based on nitrogen incorporated ultrananocrystalline diamond film has been fabricated to be used as the electron source of this flat panel x-ray source. The FEA prototype was developed using conventional microfabrication techniques. The field emission characteristics of the FEA prototype were evaluated. Results indicated that emission current densities of the order of 6 mA/cm2 could be obtained at electric fields as low as 10 V/μm to 20 V/μm. During the prototype microfabrication process, issues such as delamination of the extraction gate and poor etching of the SiO2 insulating layer located between the emitters and the extraction layer were encountered. Consequently, alternative FEA designs were investigated. Experimental and simulation data from the first FEA prototype were compared and the results were used to evaluate the performance of alternative single and double gate designs that would yield better field emission characteristics compared to the first FEA prototype. The best simulation results are obtained for the double gate FEA design, when the diameter of the collimator gate is around 2.6 times the diameter of the extraction gate.
Magnetic defects in chemically converted graphene nanoribbons: electron spin resonance investigation
Authors: Singamaneni Srinivasa Rao , Stesmans Andre , van Tol Johan , Kosynkin D. V. , Tour James M.
Published: April 2014

Electronic spin transport properties of graphene nanoribbons (GNRs) are influenced by the presence of adatoms, adsorbates and edge functionalization. To improve the understanding of the factors that influence the spin properties of GNRs, local (element) spin-sensitive techniques such as electron spin resonance (ESR) spectroscopy are important for spintronics applications. Here, we present results of multi-frequency continuous wave (CW), pulse and hyperfine sublevel correlation (HYSCORE) ESR spectroscopy measurements performed on oxidatively unzipped graphene nanoribbons (GNRs), which were subsequently chemically converted (CCGNRs) with hydrazine. ESR spectra at 336 GHz reveal an isotropic ESR signal from the CCGNRs, of which the temperature dependence of its line width indicates the presence of localized unpaired electronic states. Upon functionalization of CCGNRs with 4-nitrobenzene diazonium tetrafluoroborate, the ESR signal is found to be 2 times narrower than that of pristine ribbons. NH3 adsorption/desorption on CCGNRs is shown to narrow the signal, while retaining the signal intensity and g value. The electron spin-spin relaxation process at 10 K is found to be characterized by slow (163 ns) and fast (39 ns) components. HYSCORE ESR data demonstrate the explicit presence of protons and 13C atoms. With the provided identification of intrinsic point magnetic defects such as proton and 13C has been reported, which are roadblocks to spin travel in graphene-based materials, this work could help in advancing the present fundamental understanding on the edge-spin (or magnetic)-based transport properties of CCGNRs.
Switchable photovoltaic response from polarization modulated interfaces in BiFeO3 thin films
Authors: Fang Liang , You Lu , Zhou Yang , Ren Peng , Shiuh Lim Zhi , Wang Junling
Published: April 2014

The switchable photovoltaic effect in BiFeO3 thin films capacitors has been studied extensively. However, the origin of the photovoltaic response is still under debate. Both bulk depolarization field and interface effects have been used to explain the observations. In this work, we fabricate BiFeO3 epitaxial films on SrTiO3 substrate with La0.7Sr0.3MnO3 and Pt as electrodes. Much larger switchable photovoltaic response can be observed in the Pt/BiFeO3/La0.7Sr0.3MnO3 samples, as compared with La0.7Sr0.3MnO3/BiFeO3/La0.7Sr0.3MnO3. Moreover, the photovoltaic voltage of the Pt/BiFeO3/La0.7Sr0.3MnO3 samples is nearly independent of the thickness of the La0.7Sr0.3MnO3 bottom electrode. We suggest that the Schottky barrier modulation by ferroelectric polarization at the Pt/BiFeO3 interface is mainly responsible for the photovoltaic effect, with very small contribution from the bulk depolarization field.
Understanding molecular structure dependence of exciton diffusion in conjugated small molecules
Authors: Li Zi , Zhang Xu , Woellner Cristiano F. , Lu Gang
Published: April 2014

First-principles simulations are carried out to understand molecular structure dependence of exciton diffusion in a series of small conjugated molecules arranged in a disordered, crystalline, and blend structure. Exciton diffusion length (LD), lifetime, and diffusivity in four diketopyrrolopyrrole derivatives are calculated and the results compare very well with experimental values. The correlation between exciton diffusion and molecular structure is examined in detail. In the disordered molecule structure, a longer backbone length leads to a shorter exciton lifetime and a higher exciton diffusivity, but it does not change LD substantially. Removal of the end alkyl chains or the extra branch on the side alkyl chains reduces LD. In the crystalline structure, exciton diffusion exhibits a strong anisotropy whose origin can be elucidated from the intermolecular transition density interaction point of view. In the blend structure, LD increases with the crystalline ratios, which are estimated and consistent with the experimental results.
Street Renaming, Symbolic Capital, and Resistance in Durban, South Africa
Authors: Duminy James
Published: April 2014

In early 2007 the African National Congress majority within the local government authority of Durban, South Africa, approved two phases of a street renaming process, which culminated in the renaming of over one hundred prominent streets after various anticolonial and antiapartheid ‘struggle heroes’. The process led to an unprecedented degree of public attention and debate, expressed through a range of arguments and symbolic gestures, and local state representatives responded by casting this opposition in terms of ‘countertransformation’. This paper examines the Durban case with a critical analytical perspective that sees acts of place naming through the heuristic frames of ‘text’, ‘arena’, and ‘performance’, drawing attention to the complex spatial and material dynamics that attend acts of symbolic transformation and resistance. It contributes to theoretical discussions surrounding “naming as symbolic resistance”, by arguing that a performative conception of symbolic capital and resistance may aid our understanding of naming processes in contested memorial landscapes.
Indigo Dreaming
Authors: Rae Ian D.
Published: April 2014

An Australian chemist who worked in Britain’s munitions industry during World War I returned home nursing the ambition to break a German monopoly and establish the manufacture of synthetic indigo in Australia. Although he mastered the chemistry, municipal concerns about industrial pollution by sulfur dioxide fumes emitted during the oxidation of naphthalene thwarted his attempt to site a factory, and he was never able to attract sufficient financial backing. As an organic chemist trained by Roger Brown, and for many years his friend and colleague, I dedicate this story to the master, who also left some dreams unrealised.
Lead electrochemical speciation analysis in seawater media by using AGNES and SSCP techniques
Authors: Díaz-de-Alba Margarita , Galindo-Riaño M. Dolores , Pinheiro José Paulo
Published: April 2014

Environmental context Metal contamination of seawater can present severe environmental problems owing to the high toxicity of metals and their persistence in the environment. This study explores the possibility of analysing lead in seawater media using two recently developed electrochemical methods. The methods are shown to be very useful tools to monitor the behaviour and fate of lead and other metals in seawater. Abstract The speciation of PbII in synthetic and real seawater is studied by absence of gradients and Nernstian equilibrium stripping (AGNES) and stripping chronopotentiometry at scanned deposition potential (SSCP). The usefulness of the combination of both techniques in the same electrochemical cell for trace metal speciation analysis is assessed at different pH values (2.7, 5.0, 6.0, 7.0 and 8.6). The AGNES (free metal ion concentrations) and SSCP (stability constants) results for synthetic seawater agree reasonably with each other and with the theoretical predictions of the software Visual MINTEQ 3.0. This is also true for real seawater media below pH 7.0. Because of the influence of natural organic matter (2.01mgL–1 total organic carbon) in the real seawater at pH 7.0 and 8.6 the SSCP signal showed that the PbII complexes became less labile and were formed by chemically heterogeneous ligands. At these pH values, free metal concentrations determined by AGNES agreed with concentrations predicted by Visual MINTEQ using a generic fulvic acid concentration.
Assessing the quality of forest fuel loading data collected using public participation methods and smartphones
Authors: Ferster Colin J. , Coops Nicholas C.
Published: April 2014

Effective wildfire management in the wildland–urban interface (WUI) depends on timely data on forest fuel loading to inform management decisions. Mobile personal communication devices, such as smartphones, present new opportunities to collect data in the WUI, using sensors within the device – such as the camera, global positioning system (GPS), accelerometer, compass, data storage and networked data transfer. In addition to providing a tool for forest professionals, smartphones can also facilitate engaging other members of the community in forest management as they are now available to a growing proportion of the general population. Approaches where the public participates in the data-collection process (inspired by citizen science) may be beneficial for fire hazard issues. This research note demonstrates a smartphone application for measuring forest fuel loading in the WUI by forestry professionals and non-professionals, and evaluates the quality of the collected data. Smartphones and their associated applications may provide new tools for collecting forest structural data in the WUI, but forest managers need to ensure that measurement protocols provide the required precision for analysis and enforce the logical consistency of observations made by a diverse set of data collectors, and that sufficient training is provided. If these recommendations are followed, we conclude that data acquired by volunteers in collaborative projects through smartphone applications can be of acceptable quality to help inform forest management decisions.
Genetically encoding a light switch in an ionotropic glutamate receptor reveals subunit-specific interfaces
Authors: Zhu Shujia , Riou Morgane , Yao C. Andrea , Carvalho Stéphanie , Rodriguez Pamela C. , Bensaude Olivier , Paoletti Pierre , Ye Shixin
Published: April 2014

Significance

The design of protein receptors responsive to light stimuli has wide-ranging applications in structure–function studies and optogenetics. We present here the design of a light-sensitive NMDA receptor by introducing through genetic-code expansion a photoreactive moiety carried by a single unnatural amino acid. NMDA receptors form glutamate-gated ion channels that are essential mediators of synaptic plasticity associated with learning and memory. By exploring the molecular mechanisms and subunit dependence of the light-induced receptor inactivation, we find that the two major NMDA receptor subtypes, GluN1/GluN2A and GluN1/GluN2B, differ in their ectodomain-subunit interactions. Besides providing important new information about NMDA receptor molecular structure, our work opens the possibility of using engineered light-sensitive NMDA receptors to explore native receptor function.
MetDisease—connecting metabolites to diseases via literature
Authors: Duren William , Weymouth Terry , Hull Tim , Omenn Gilbert S. , Athey Brian , Burant Charles , Karnovsky Alla
Published: April 2014

Motivation: In recent years, metabolomics has emerged as an approach to perform large-scale characterization of small molecules in biological systems. Metabolomics posed a number of bioinformatics challenges associated in data analysis and interpretation. Genome-based metabolic reconstructions have established a powerful framework for connecting metabolites to genes through metabolic reactions and enzymes that catalyze them. Pathway databases and bioinformatics tools that use this framework have proven to be useful for annotating experimental metabolomics data. This framework can be used to infer connections between metabolites and diseases through annotated disease genes. However, only about half of experimentally detected metabolites can be mapped to canonical metabolic pathways. We present a new Cytoscape 3 plug-in, MetDisease, which uses an alternative approach to link metabolites to disease information. MetDisease uses Medical Subject Headings (MeSH) disease terms mapped to PubChem compounds through literature to annotate compound networks.

Availability and implementation: MetDisease can be downloaded from http://apps.cytoscape.org/apps/metdisease or installed via the Cytoscape app manager. Further information about MetDisease can be found at http://metdisease.ncibi.org

Contact:  akarnovs@med.umich.edu

Supplementary information:  Supplementary Data are available at Bioinformatics online
Robustness of differentiation cascades with symmetric stem cell division
Authors: Sánchez-Taltavull Daniel , Alarcón Tomás
Published: April 2014

Stem cells (SCs) perform the task of maintaining tissue homeostasis by both self-renewal and differentiation. While it has been argued that SCs divide asymmetrically, there is also evidence that SCs undergo symmetric division. Symmetric SC division has been speculated to be key for expanding cell numbers in development and regeneration after injury. However, it might lead to uncontrolled growth and malignancies such as cancer. In order to explore the role of symmetric SC division, we propose a mathematical model of the effect of symmetric SC division on the robustness of a population regulated by a serial differentiation cascade and we show that this may lead to extinction of such population. We examine how the extinction likelihood depends on defining characteristics of the population such as the number of intermediate cell compartments. We show that longer differentiation cascades are more prone to extinction than systems with less intermediate compartments. Furthermore, we have analysed the possibility of mixed symmetric and asymmetric cell division against invasions by mutant invaders in order to find optimal architecture. Our results show that more robust populations are those with unfrequent symmetric behaviour.
Positive interactions between herbivores and plant diversity shape forest regeneration
Authors: Cook-Patton Susan C. , LaForgia Marina , Parker John D.
Published: April 2014

The effects of herbivores and diversity on plant communities have been studied separately but rarely in combination. We conducted two concurrent experiments over 3 years to examine how tree seedling diversity, density and herbivory affected forest regeneration. One experiment factorially manipulated plant diversity (one versus 15 species) and the presence/absence of deer (
Odocoileus virginianus
). We found that mixtures outperformed monocultures only in the presence of deer. Selective browsing on competitive dominants and associational protection from less palatable species appear responsible for this herbivore-driven diversity effect. The other experiment manipulated monospecific plant density and found little evidence for negative density dependence. Combined, these experiments suggest that the higher performance in mixture was owing to the acquisition of positive interspecific interactions rather than the loss of negative intraspecific interactions. Overall, we emphasize that realistic predictions about the consequences of changing biodiversity will require a deeper understanding of the interaction between plant diversity and higher trophic levels. If we had manipulated only plant diversity, we would have missed an important positive interaction across trophic levels: diverse seedling communities better resist herbivores, and herbivores help to maintain seedling diversity.
A one-dimensional ladder-like six-coordinate cadmium polymer: catena-poly[bis[(S)-2-methylpiperazine-1,4-diium] [bis[trichloridocadmium(II)]-di-μ3-chlorido]]
Authors: Wu De-Hong
Published: April 2014

The crystal structure of the title compound {(C5H14N2)2[Cd2Cl8]}
n
, (I), consists of hydrogen-bonded 2-methylpiperazinediium (H2MPPA2+) cations in the presence of one-dimensional polymeric {[CdCl3(μ3-Cl)]2−}
n
anions. The CdII centres are hexacoordinated by three terminal chlorides and three bridging chlorides and have a slightly distorted octahedral CdCl3(μ3-Cl)3 arrangement. The alternating CdCl6 octahedra form four-membered Cd2Cl2 rings by the sharing of neighbouring Cd–Cl edges to give rise to extended one-dimensional ladder-like chains parallel to the b axis, with a Cd...Cd distance of 4.094 (2) Å and a Cd...Cd...Cd angle of 91.264 (8)°. The H2MPPA2+ cations crosslink the [CdCl3(μ3-Cl)]
n
chains by the formation of two N—H...Cl hydrogen bonds to each chain, giving rise to one-dimensional ladder-like H2MPPA2+–Cl2 hydrogen-bonded chains [graph set R
4
2(14)]. The [CdCl3(μ3-Cl)]
n
chains are interwoven with the H2MPPA2+–Cl2 hydrogen-bonded chains, giving rise to a three-dimensional supramolecular network.
Autism spectrum mixed neurodevelopmental disorder associated with 6q27 deletion and multiple copies within 20q11.23: a case study
Authors: Hopkins Stephen , Turk Jeremy , Daramola Adeniyi , Kyriakopoulos Marinos
Published: April 2014

Purpose

– Copy Number Variations (CNVs) are not infrequently observed in aberrant neurodevelopment. CNVs can alter gene expression and have been linked to a wide range of neuropsychiatric disorders. The purpose of this case study is to report the association of CNVs with a mixed neurodevelopmental disorder.

Design/methodology/approach

– Array-Comparative Genomic Hybridisation analysis was carried out in a case of an eight-year-old boy presenting with a mixed neurodevelopmental disorder including autism spectrum disorder, intellectual disability, tic disorder, anxiety and severe aggression. The child's parents also underwent the same investigation.

Findings

– A 6q27 deletion and multiple copies within 20q11.23 were identified. The boy's father shared the 6q27 deletion and his mother also had multiple copies within 20q11.23.

Originality/value

– This is the first report linking the combination of 6p27 and 20q11 CNVs with a mixed neurodevelopmental presentation. Identifying CNVs that may underlie aberrant neurodevelopment is likely to assist in unravelling the aetiology of neurodevelopmental and psychiatric disorders and lead to more effective strategies for their characterisation and management.
The importance of developing confidence and self-esteem in children with a learning disability
Authors: Goleniowska Hayley
Published: April 2014

Purpose

– The purpose of this paper is to look at the importance of self-esteem in individuals with a learning disability.

Design/methodology/approach

– The paper explore ways of developing self-esteem and confidence with simple techniques for parents and carers of those with learning disabilities to try.

Findings

– Anecdotal examples are given by a mother of a child who has Down's Syndrome. The paper outlines ways parents and professionals can increase the self-worth of individuals with a learning disability through fun play, encouraging relevant social and life skills, even safe risk taking. The paper outlines the need for accepting and praising your child for who they are as well as seeking out positive role models.

Originality/value

– Self-esteem and confidence are crucial ingredients in giving people with learning disabilities a sense of well-being and of beings valued member of a community. They are also key in keeping depression and loneliness at bay.
Impediments to market orientation
Authors: Siddique C. M.
Published: April 2014

Purpose

– This study was undertaken to explore obstacles to market orientation in the retail small- and medium-sized retail enterprises (SME) sector of the United Arab Emirates (UAE), a rapidly growing economy in the Gulf region. The paper aims to discuss these issues.

Design/methodology/approach

– The study used a triangulation data collection approach, including a case study, participant observation, and a questionnaire-based survey. Five research hypotheses were developed on context-specific impediments to market orientation, identified by means of in-depth interviews with owners/operators of SMEs, their channel partners and customers, and were tested with survey data.

Findings

– The study revealed a weak market orientation among UAE-based retail SMEs. An undifferentiated competition, limited resource infrastructure, and a short-term planning horizon occurred as the major impediments to the development and implementation of a market orientation. SMEs that preferred to maintain the status quo, and those who perceived UAE ' s commercial environment as lenient and pro-business, also expressed a lack of interest in the marketing concept and market orientation as a competitive strategy.

Research limitations/implications

– The study supports the contention that social-structural conditions and business practices can create formidable barriers to a market orientation in emerging markets. The findings call for shifting the current research focus from intra-organizational antecedents of market orientation to context-specific factors that may impede or facilitate market orientation.

Originality/value

– The study unravels a unique set of impediments to market orientation in UAE ' s retail sector and thus contributes to the ongoing interest of marketing scholars in expanding the range of possible antecedents of a market orientation. The findings of this study should be of special interest to foreign business firms aspiring to enter the growing retail sector of UAE and other emerging markets in the Gulf region.
English recreational reading habits of Arab Jordanian EFL tertiary students
Authors: Khreisat Mohammad N. , Kaur Sarjit
Published: April 2014

Purpose

– This study aims to investigate English recreational reading habits of Arab Jordanian EFL university students when classes are in session and during vacation, and the types of recreational reading they engage in. In addition, the study explores other relationships such as the relationship between reading habits and students
'
cumulative grade point average (CGPA); and the effect of parents
'
educational level and their time spent on reading.

Design/methodology/approach

– The respondents, comprising 225 third- and fourth-year English majors, completed an English recreational reading habits questionnaire. The study utilised a non-probability sampling method, namely, purposive sampling. Data were analysed using IBM SPSS software v. 20.

Findings

– The findings indicated that students read more when they were on vacation compared to their readings while classes are in session. The students
'
average time spent on reading when classes are in session and during vacation is 2.15 hours and 2.82 hours per week, respectively. Slightly more than half (57 percent) the students always read emails/chat rooms/Facebook, which are their most preferred type of recreational reading. Non-fiction books were the least favourite among students with 47 percent of students indicating that they never or rarely read this type of genre. Among all the reading interests, only novels had a significant correlation with the students
'
CGPA. The findings showed that the respondents with higher levels of fathers
'
education were significantly reading more.

Originality/value

– The reading habits of EFL students have received little attention and there is limited research that surveyed Arab EFL students
'
recreational reading habits at the tertiary level. The purpose of this study is to address this gap in the literature and set out to be a point of reference and comparison for future investigations about English recreational reading habits of Arab EFL tertiary students.
The enculturation of pre-service Emirati English language teachers
Authors: Sandiford Carmel
Published: April 2014

Purpose

– This article aims to report on a qualitative study that investigates the enculturation of a group of pre-service English language teachers over four years of a Bachelor of Education degree offered in a women ' s college in the United Arab Emirates.

Design/methodology/approach

– Bourdieu ' s “thinking tools” of field, habitus and capital provide the overarching theoretical framework and analytic tools to examine the processes of enculturation which impact on the student teachers as they participate in a program based on Western-oriented theories and practices. The study draws upon data gathered from focus group interviews with student teachers in the first and fourth years of the program to provide insights into their ways of thinking as future Emirati English language teachers. The article discusses the priorities that emerge as these student teachers validate, or otherwise, the theoretical principles and practices legitimated through the program.

Findings

– The findings suggest that influences bound by local, cultural and social forces contribute significantly to the student teachers ' perceived capacity to think and act as future Emirati English language teachers.

Research limitations/implications

– The study is limited to one site but, given the findings, similar investigations into processes of enculturation and the appropriation or resistance of essential aspects of English language teacher training could be undertaken.

Originality/value

– There is limited research into English language teacher education programs in the Arab world. This research has potential applications for English language teacher education programs where there is intent to effect educational reform.
Corporate social responsibility: perspectives of hotel frontline employees
Authors: Park Sun-Young , E. Levy Stuart
Published: April 2014

Purpose

– The aim of this paper is to examine hotel frontline employees' perceptions of corporate social responsibility (CSR) activities at the hotel they currently work, and how their perceptions influence their level of organizational identification, an indicator of their relationship quality with the hotel.

Design/methodology/approach

– This study uses 575 responses of hotel frontline employees in the US, collected through a national online survey.

Findings

– Results show that hotel employees' perceptions of CSR activities encompass the host community, colleagues, and customers, beyond green practices. Moreover, their perceptions of CSR activities positively and significantly influence the level of organizational identification.

Research limitations/implications

– The results of this exploratory study should not be generalized to all frontline employees in the US hotel industry. Future studies should extend this study to examine potential relationships among other variables relevant to organizational identification, and in other hospitality industry contexts. Also, this study does not seek to question the merits of CSRper se, as it takes a managerial perspective to assist hoteliers' understanding of and decision-making on CSR.

Practical implications

– As CSR activities often represent company values and norms, frontline employees' perceptions of them can influence how they identify with the company, which is an impetus for their attitudinal and behavioral support to help achieve the company's goals. Accordingly, CSR activities can be a critical tool in engaging frontline employees to achieve better performance and derive more meaning in their careers, and in attracting good quality employees.

Originality/value

– This study is a first attempt to empirically examine how CSR activities can benefit hotel employees, based on various literatures on service-profit-chain, CSR, and social identity theory.
Personality predictors of team taskwork understanding and transactive memory systems in service management teams
Authors: Guchait Priyanko , Hamilton Katherine , Hua Nan
Published: April 2014

Purpose

– The aim of this paper is to examine how personality composition in teams related to team taskwork understanding (TTU) and transactive memory systems (TMS) over time. Additionally, the study examined the relationship between TTU and TMS, and three team criteria variables: performance, satisfaction, and cohesion.

Design/methodology/approach

– A longitudinal study was conducted with 27 service management teams involving 178 undergraduate students in a restaurant setting. The restaurant was open to the public so the team outcomes had real world consequences. Each team served between 90-140 customers.

Findings

– Results showed that team mean-level conscientiousness was significantly positively related to TTU and TMS in the initial stage of team formation. On the other hand, team mean-level agreeableness had a significant positive relationship with TTU and TMS later on in the team's lifecycle. Furthermore, significant positive relationships were found between TMS and team performance, TMS and team satisfaction, and TTU and team cohesion.

Originality/value

– The current work looked at how various team cognitions develop in teams over time as a result of personality composition in teams which has not been tested before. Unlike prior research, this study was conducted in a field setting instead of an experimental study in the laboratory. Finally, no research exists studying these relationships in a hospitality context. Therefore, the current work extends the generalizability of the team composition and team cognition theories.
The role of cognitive validity testing in the development of CALL, the comprehensive assessment of leadership for learning
Authors: H. Blitz Mark , Salisbury Jason , Kelley Carolyn
Published: April 2014

Purpose

– The Comprehensive Assessment of Leadership for Learning (CALL) is an online task-based assessment of distributed instructional leadership. In developing CALL, researchers faced the challenge of structuring survey items that would measure leadership practice rather than individual traits. Critical in this work was developing items that accurately reflected current leadership practice. Therefore, the purpose of this paper is to pilot the CALL instrument and conducted cognitive validity testing on the instrument.

Design/methodology/approach

– CALL researchers piloted the survey in six schools in Wisconsin in order to test and refine the survey instrument. Researchers conducted cognitive walk-through interviews with five participants from each school: principals, associate principals, teachers, department chairs, guidance counselors, and activities directors. The interviews focussed on specific items in order to observe the users’ thought processes and rationale in choosing a response for each item. The researchers focussed on relevancy, clarity, and accuracy of survey items in collecting and analyzing the resulting data.

Findings

– Three specific survey items were identified that exemplify these challenges and opportunities such as: accessible language, extended leadership, socially desirable responding, 360-degree perspectives, applying appropriate terminology, and identifying appropriate practices. These findings provided insight into survey development work and implications of distributed leadership. The authors discuss the challenges of creating a task-based leadership assessment.

Originality/value

– Developing a formative assessment of school leadership is valuable in supporting school leaders’ work. The process of utilizing a qualitative approach to develop a quantitative instrument has proven critical in measuring task-based distributed leadership.
German real estate funds: changes in return distributions and portfolio favourability
Authors: Stein Michael
Published: April 2014

Purpose

– Since 2008, the German open-ended real estate fund (GOEREF) industry has experienced a critical phase of suspensions of redemption of fund shares, announced fund terminations and, eventually, introduction of a new regulation. With assets under the management of over 80 billion, GOEREFs are the dominant indirect real estate investment vehicle in Germany. Thus, it is extremely important to study the effects of this crisis on the risk and return characteristics of the respective funds. The paper aims to discuss these issues.

Design/methodology/approach

– Both net asset values (NAVs) and potential secondary market prices of the shares of funds with suspended redemptions are used. The resulting total return patterns are analysed on an index basis for fund groups that best represent the most important investor groups for GOEREFs.

Findings

– Groups that comprised a higher number of funds with suspended redemptions were considerably worse off and less attractive in an asset allocation context than the others given the often much lower secondary market prices. However, changes in return and risk must also be considered in terms of NAVs. The fund group comprising co-operative savings banks' funds was virtually unaffected by the liquidity crisis and continued to deliver stable and non-volatile returns, while the other fund groups exhibited a clear shift in their respective return profiles.

Originality/value

– This study analyses fund groups that reflect the most important investor groups by using both types of important prices in a comprehensive industry sample. It, thus, provides valuable insights into the changing profiles of the funds and groups and their favourability from an asset allocation perspective.
Effect of a leadership intervention on subordinate well-being
Authors: Elo Anna-Liisa , Ervasti Jenni , Kuosma Eeva , Mattila-Holappa Pauliina
Published: April 2014

Purpose

– Leadership behaviours are shown to contribute to subordinate well-being. The purpose of this paper is to investigate the effect of a 7.5-day personal growth-orientated leadership intervention among line supervisors on subordinate well-being at work in a public sector construction organization.

Design/methodology/approach

– A quasi-experimental design was applied to investigate the effects on the subordinates’ perceptions of the psychosocial work environment, leadership, and well-being. The intervention group comprised the subordinates (n=49) of the leadership intervention units and the control group comprised the subordinates (n=96) of the non-participating units. Data were collected with pre- and post-measurement surveys and analysed with repeated measures ANCOVA.

Findings

– The intervention improved the flow of information after adjusting for the subordinates’ level of participation in the organizational stress management programme and background variables. The subordinates’ perception of leadership or of their own well-being did not improve compared to the control group.

Research limitations/implications

– More detailed and proximal outcome indicators are needed. Several measurements and a process evaluation of the implementation are recommended.

Practical implications

– Line supervisors need to be informed about the goals and methods of a personal growth intervention in order to encourage them to meet their strengths and limitations. The improvement of blue-collar subordinate well-being through leadership development might benefit from more practical training approaches.

Originality/value

– The personal growth approach to line supervisors’ development is rare. The effect of the development on subordinate well-being has not been investigated.