bluuebunny/crossref_metadata_2025 huggingface dataset:
Nonlinear regime of electrostatic waves propagation in presence of electron-electron collisions
Authors: Pezzi Oreste , Valentini Francesco , Veltri Pierluigi
Published: April 2015

The effects are presented of including electron-electron collisions in self-consistent Eulerian simulations of electrostatic wave propagation in nonlinear regime. The electron-electron collisions are approximately modeled through the full three-dimensional Dougherty collisional operator [J. P. Dougherty, Phys. Fluids 7, 1788 (1964)]; this allows the elimination of unphysical byproducts due to reduced dimensionality in velocity space. The effects of non-zero collisionality are discussed in the nonlinear regime of the symmetric bump-on-tail instability and in the propagation of the so-called kinetic electrostatic electron nonlinear (KEEN) waves [T. W. Johnston et al., Phys. Plasmas 16, 042105 (2009)]. For both cases, it is shown how collisions work to destroy the phase-space structures created by particle trapping effects and to damp the wave amplitude, as the system returns to the thermal equilibrium. In particular, for the case of the KEEN waves, once collisions have smoothed out the trapped particle population which sustains the KEEN fluctuations, additional oscillations at the Langmuir frequency are observed on the fundamental electric field spectral component, whose amplitude decays in time at the usual collisionless linear Landau damping rate.
A theoretical approach to La L1-edge XANES spectra of La complex oxides and their local configuration
Authors: Asakura Hiroyuki , Shishido Tetsuya , Teramura Kentaro , Tanaka Tsunehiro
Published: April 2015

The characteristic peaks (pre-edge peaks) in the La L1-edge X-ray absorption near edge structure (XANES) of various La complex oxides were analyzed by both experimental and theoretical approaches. The pre-edge peak areas are correlated with the bond angle analysis (BAA) parameter, which we proposed as an indicator of the centrosymmetry or disorder of the local configuration of the La site. The origin of the pre-edge peak and the parameterization criteria of the BAA parameter were evaluated using theoretical calculations based on molecular orbital theory and multiple scattering theory. The theoretical calculations showed that the origin of the pre-edge peak at the La L1-edge is electric dipole transition from 2s to unoccupied states generated by p–d hybridization. Medium-scale theoretical simulations of the La L1-edge XANES spectra of thousands of virtual La aqueous complex models verified that the parameterization criteria of the BAA parameter are applicable to local configuration analysis of La.
Hierarchical elasticity of bimesogenic liquid crystals with twist-bend nematic phase
Authors: Yun Chang-Jun , Vengatesan M. R. , Vij Jagdish K. , Song Jang-Kun
Published: April 2015

In 2001, Dozov predicted that twist-bend nematic phase can be spontaneously formed when K33 < 0 and K11/K22 > 2, and this phase has recently been discovered in bimesogens. To verify Dozov's hypothesis, we have measured precisely the temperature dependence of the elastic constants of CB7CB in the entire temperature range of nematic phase and in twist-bend nematic phase close to the transition temperature by combing the Fréedericksz threshold methods for a twist nematic and an in-plane switching cells. Anomalous changes in K22 and K33 are observed across the phase transition. The elasticity estimated via extrapolation of the data in the high temperature region of the nematic phase seems to fully satisfy Dozov's hypothesis although the elasticity data in the vicinity of the phase transition exhibit opposite trends. This can be explained by the general nature of a hierarchical system where the macroscopic elasticity is governed mostly by the distortion of a higher level structure.
Effect of hole transport on performance of infrared type-II superlattice light emitting diodes
Authors: Lin Youxi , Suchalkin Sergey , Kipshidze Gela , Hosoda Takashi , Laikhtman Boris , Westerfeld David , Shterengas Leon , Belenky Gregory
Published: April 2015

The effect of hole transport on the performance of infrared light emitting diodes (LED) was investigated. The active area of the LEDs comprised two type-II superlattices with different periods and widths connected in series. Electroluminescence spectra of the devices with different positions of long wave and mid wave superlattice sections were mostly contributed by the superlattice closest to the p-contact. The experimental results indicate that due to suppressed vertical hole transport, the recombination of electrically injected electrons and holes in a type II superlattice LED active region takes place within a few superlattice periods near p-barrier. Possible reason for the effect is reduction of hole diffusion coefficient in an active area of a superlattice LED under bias.
Instability of a two-dimensional viscous flow in an annulus with permeable walls to two-dimensional perturbations
Authors: Ilin Konstantin , Morgulis Andrey
Published: April 2015

The stability of a two-dimensional viscous flow in an annulus with permeable walls with respect to small two-dimensional perturbations is studied. The basic steady flow is the most general rotationally invariant solution of the Navier-Stokes equations in which the velocity has both radial and azimuthal components, and the azimuthal velocity profile depends on the radial Reynolds number. It is shown that for a wide range of parameters of the problem, the basic flow is unstable to small two-dimensional perturbations. Neutral curves in the space of parameters of the problem are computed. Calculations show that the stability properties of this flow are determined by the azimuthal velocity at the inner cylinder when the direction of the radial flow is from the inner cylinder to the outer one and by the azimuthal velocity at the outer cylinder when the direction of the radial flow is reversed. This work is a continuation of our previous study of an inviscid instability in flows between rotating porous cylinders [K. Ilin and A. Morgulis, “Instability of an inviscid flow between porous cylinders with radial flow,” J. Fluid Mech. 730, 364–378 (2013)].
Vanishing current hysteresis under competing nuclear spin pumping processes in a quadruplet spin-blockaded double quantum dot
Authors: Amaha S. , Hatano T. , Tarucha S. , Gupta J. A. , Austing D. G.
Published: April 2015

We investigate nuclear spin pumping with five-electron quadruplet spin states in a spin-blockaded weakly coupled vertical double quantum dot device. Two types of hysteretic steps in the leakage current are observed on sweeping the magnetic field and are associated with bidirectional polarization of nuclear spin. Properties of the steps are understood in terms of bias-voltage-dependent conditions for the mixing of quadruplet and doublet spin states by the hyperfine interaction. The hysteretic steps vanish when up- and down-nuclear spin pumping processes are in close competition.
Single-crystalline CuO nanowires for resistive random access memory applications
Authors: Hong Yi-Siang , Chen Jui-Yuan , Huang Chun-Wei , Chiu Chung-Hua , Huang Yu-Ting , Huang Ting Kai , He Ruo Shiuan , Wu Wen-Wei
Published: April 2015

Recently, the mechanism of resistive random access memory (RRAM) has been partly clarified and determined to be controlled by the forming and erasing of conducting filaments (CF). However, the size of the CF may restrict the application and development as devices are scaled down. In this work, we synthesized CuO nanowires (NW) (∼150 nm in diameter) to fabricate a CuO NW RRAM nanodevice that was much smaller than the filament (∼2 μm) observed in a bulk CuO RRAM device in a previous study. HRTEM indicated that the Cu2O phase was generated after operation, which demonstrated that the filament could be minimize to as small as 3.8 nm when the device is scaled down. In addition, energy dispersive spectroscopy (EDS) and electron energy loss spectroscopy (EELS) show the resistive switching of the dielectric layer resulted from the aggregated oxygen vacancies, which also match with the I-V fitting results. Those results not only verify the switching mechanism of CuO RRAM but also show RRAM has the potential to shrink in size, which will be beneficial to the practical application of RRAM devices.
Label-free spectroscopic detection of membrane potential using stimulated Raman scattering
Authors: Liu Bin , Lee Hyeon Jeong , Zhang Delong , Liao Chien-Sheng , Ji Na , Xia Yuanqin , Cheng Ji-Xin
Published: April 2015

Hyperspectral stimulated Raman scattering microscopy is deployed to measure single-membrane vibrational spectrum as a function of membrane potential. Using erythrocyte ghost as a model, quantitative correlation between transmembrane potential and Raman spectral profile was found. Specifically, the ratio between the area under Raman band at ∼2930 cm−1 and that at ∼2850 cm−1 increased by ∼2.6 times when the potential across the erythrocyte ghost membrane varied from +10 mV to −10 mV. Our results show the feasibility of employing stimulated Raman scattering microscopy to probe the membrane potential without labeling.
Single-charge transport in ambipolar silicon nanoscale field-effect transistors
Authors: Mueller Filipp , Konstantaras Georgios , van der Wiel Wilfred G. , Zwanenburg Floris A.
Published: April 2015

We report single-charge transport in ambipolar nanoscale MOSFETs, electrostatically defined in near-intrinsic silicon. We use the ambipolarity to demonstrate the confinement of either a few electrons or a few holes in exactly the same crystalline environment underneath a gate electrode. We find similar electron and hole quantum dot properties while the mobilities differ quantitatively like in microscale devices. The understanding and control of individual electrons and holes are essential for spin-based quantum information processing.
The cluster model of a hot dense vapor
Authors: Zhukhovitskii D. I.
Published: April 2015

We explore thermodynamic properties of a vapor in the range of state parameters where the contribution to thermodynamic functions from bound states of atoms (clusters) dominates over the interaction between the components of the vapor in free states. The clusters are assumed to be light and sufficiently “hot” for the number of bonds to be minimized. We use the technique of calculation of the cluster partition function for the cluster with a minimum number of interatomic bonds to calculate the caloric properties (heat capacity and velocity of sound) for an ideal mixture of the lightest clusters. The problem proves to be exactly solvable and resulting formulas are functions solely of the equilibrium constant of the dimer formation. These formulas ensure a satisfactory correlation with the reference data for the vapors of cesium, mercury, and argon up to moderate densities in both the sub- and supercritical regions. For cesium, we extend the model to the densities close to the critical one by inclusion of the clusters of arbitrary size. Knowledge of the cluster composition of the cesium vapor makes it possible to treat nonequilibrium phenomena such as nucleation of the supersaturated vapor, for which the effect of the cluster structural transition is likely to be significant.
Experimental observation of sub-Rayleigh quantum imaging with a two-photon entangled source
Authors: Xu De-Qin , Song Xin-Bing , Li Hong-Guo , Zhang De-Jian , Wang Hai-Bo , Xiong Jun , Wang Kaige
Published: April 2015

It has been theoretically predicted that N-photon quantum imaging can realize either an N-fold resolution improvement (Heisenberg-like scaling) or a N-fold resolution improvement (standard quantum limit) beyond the Rayleigh diffraction bound, over classical imaging. Here, we report the experimental study on spatial sub-Rayleigh quantum imaging using a two-photon entangled source. Two experimental schemes are proposed and performed. In a Fraunhofer diffraction scheme with a lens, two-photon Airy disk pattern is observed with subwavelength diffraction property. In a lens imaging apparatus, however, two-photon sub-Rayleigh imaging for an object is realized with super-resolution property. The experimental results agree with the theoretical prediction in the two-photon quantum imaging regime.
Enhanced linear magnetoresistance of germanium at room temperature due to surface imperfection
Authors: Chen Jiaojiao , Piao Hong-Guang , Luo Zhaochu , Zhang Xiaozhong
Published: April 2015

We report an enhanced linear magnetoresistance in germanium at room temperature. The magnetic-field dependence shows no saturation at magnetic fields (B) up to 4 T and the magnetoresistance sensitivity at low fields (B < 0.4 T) can reach ∼8 T−1. It is found that this magnetoresistance effect is ascribed to surface imperfection, which cannot only increase the recombination rate but also enhance the inhomogeneity. Our work may be attractive to the magnetic-field sensing industry and make germanium-based magnetoelectronics further developed.
Spin-phonon study of EuMn2O5 nanorods
Authors: Hsu Ting-Wei , Yang Chung-Cheun , Tong Yong-Xiang , Shih Wei-Jhe , Lin Kuen-Song
Published: April 2015

EuMn2O5 multiferroic nanorods, with diameters radial × (〈LC〉) lengths of 25(6) nm × 47(15) nm and 51(16) nm × 70(26) nm, were fabricated by the hydrothermal method. Ferrimagnetic ordering below 50 K (T*) is observed in the ⟨LC⟩ = 70 nm sample, which exhibited ferromagnetic (FM) behavior below T* in a field cooling process. No similar behavior was found in the ⟨LC⟩ = 47 nm sample. These observations reveal that only the ⟨LC⟩ = 70 nm sample has a meta-FM state, and this sample exhibits the stronger coupling between the Mn ions. Raman spectra of both sets of samples were obtained in 0, 610, 1000, 1600, and 2000 G magnetic fields. The red-shift of the Ag (681 cm−1) mode of the both samples increased with the strength of the field above 1000 G, indicating the existence of spin-phonon interaction. The smaller sampled exhibited a larger red-shift, suggesting that the size importantly affects the of EuMn2O5 nanorods.
A lightweight yet sound-proof honeycomb acoustic metamaterial
Authors: Sui Ni , Yan Xiang , Huang Tai-Yun , Xu Jun , Yuan Fuh-Gwo , Jing Yun
Published: April 2015

In this letter, a class of honeycomb acoustic metamaterial possessing lightweight and yet sound-proof properties is designed, theoretically proven, and then experimentally verified. It is here reported that the proposed metamaterial having a remarkably small mass per unit area at 1.3 kg/m2 can achieve low frequency (<500 Hz) sound transmission loss (STL) consistently greater than 45 dB. Furthermore, the sandwich panel which incorporates the honeycomb metamaterial as the core material yields a STL that is consistently greater than 50 dB at low frequencies. The proposed metamaterial is promising for constructing structures that are simultaneously strong, lightweight, and sound-proof.
Observation of orbiting resonances in He(3S1) + NH3 Penning ionization
Authors: Jankunas Justin , Jachymski Krzysztof , Hapka Michał , Osterwalder Andreas
Published: April 2015

Resonances are among the clearest quantum mechanical signatures of scattering processes. Previously, shape resonances and Feshbach resonances have been observed in inelastic and reactive collisions involving atoms or diatomic molecules. Structure in the integral cross section has been observed in a handful of elastic collisions involving polyatomic molecules. The present paper presents the observation of shape resonances in the reactive scattering of a polyatomic molecule, NH3. A merged-beam study of the gas phase He(3S1) + NH3 Penning ionization reaction dynamics is described in the collision energy range 3.3 μeV < Ecoll < 10 meV. In this energy range, the reaction rate is governed by long-range attraction. Peaks in the integral cross section are observed at collision energies of 1.8 meV and 7.3 meV and are assigned to ℓ = 15,16 and ℓ = 20,21 partial wave resonances, respectively. The experimental results are well reproduced by theoretical calculations with the short-range reaction probability Psr = 0.035. No clear signature of the orbiting resonances is visible in the branching ratio between NH3+ and NH2+ formation.
Electrical excitation of silicon-vacancy centers in single crystal diamond
Authors: Berhane Amanuel M. , Choi Sumin , Kato Hiromitsu , Makino Toshiharu , Mizuochi Norikazu , Yamasaki Satoshi , Aharonovich Igor
Published: April 2015

Electrically driven emission from negatively charged silicon-vacancy (SiV)− centers in single crystal diamond is demonstrated. The SiV centers were generated using ion implantation into an i region of a p-i-n single crystal diamond diode. Both electroluminescence and the photoluminescence signals exhibit the typical emission that is attributed to the (SiV)− centers. Under forward and reversed biased PL measurements, no signal from the neutral (SiV)0 defect could be observed. The realization of electrically driven (SiV)− emission is promising for scalable nanophotonics devices employing color centers in single crystal diamond.
Can top-down and bottom-up forces explain phytoplankton structure in a subtropical and shallow groundwater-connected lake?
Authors: Frau Diego , Devercelli Melina , José de Paggi Susana , Scarabotti Pablo , Mayora Gisela , Battauz Yamila , Senn Mariana
Published: April 2015

Bottom-up and top-down control of phytoplankton is one of the most important hypothesis that explains and predicts the structure of aquatic community. Our aim was to elucidate whether predation and resource limitation can control phytoplankton composition and abundance in a subtropical shallow lake with groundwater connection to the river system. During 12 months, the lake was sampled at three points. Physico-chemical parameters, phytoplankton and zooplankton were sampled fortnightly, whereas fish were sampled every 3 months. The results showed that Euglenophyta dominated the total biovolume, followed by Dinophyta and Cryptophyta. As for the species composition, Chlorophyta was the dominant group (80 species recorded), followed by phylum Cyanobacteria (26 species recorded). Redundancy analysis (RDA) indicated that temperature and nitrate + nitrite concentration mainly explained biovolume changes, with zooplankton predation not having any measurable effect on phytoplankton during the high-water (HW) period. During low-water (LW) period top-down by fish was more important. At higher taxonomic resolution (species biovolume), phosphorus was another controlling factor. We concluded that phytoplankton in this lake is mainly regulated by hydrological changes as a macrofactor that affects nutrient availability and other environmental conditions. Even though bottom-up top-down forces do not have a central effect, we found evidence of positive nutrient influences at the HW period and fish effect at the LW period.
Ceasefire: minimal aggression among Murray River crayfish feeding upon patches of allochthonous material
Authors: Starrs Danswell , Ebner Brendan C. , Fulton Christopher J.
Published: April 2015

Transport and processing of allochthonous material is crucial for trophic pathways in headwater streams. Freshwater crayfish are known to affect and exploit the break-down of in-stream terrestrial plant material into detritus. We recorded Euastacus armatus (Murray River crayfish) individuals feeding on discrete patches of allochthonous material within an unregulated section of the Goodradigbee River, an upland stream in temperate Australia. Despite suggestions of aggressive territoriality, E. armatus were observed by remote and manual underwater filming to feed in non-aggressive aggregations on these piles of fine woody debris and leaf litter. On the basis of observations of 25 individuals found in the vicinity of the allochthonous patches, this population comprised mostly female individuals at smaller sizes of maturity than has been recorded for lowland populations of E. armatus. Our study confirms the importance of concentrated allochthonous food patches for detritivores, and points to the important trophic linkage between terrestrial and aquatic ecosystems via a widespread and iconic freshwater invertebrate. Moreover, these non-aggressive feeding aggregations of E. armatus challenge notions of aggression in this species that have been developed in small-scale aquarium studies.
The first complete mitochondrial genome of Pygopodidae (Aprasia parapulchella Kluge)
Authors: MacDonald Anna J. , Knopp Theresa , Pepper Mitzy , Keogh J. Scott , Sarre Stephen D.
Published: April 2015

The Pygopodidae comprise an enigmatic group of legless lizards endemic to the Australo-Papuan region. Here we present the first complete mitochondrial genome for a member of this family, Aprasia parapulchella, from Australia. The mitochondrial genome of A. parapulchella is 16 528 base pairs long and contains 13 protein-coding genes, 22 tRNA genes, two rRNA genes and the control region, conforming to the typical vertebrate gene order. The overall mitochondrial nucleotide composition is 31.7% A, 24.5% T, 30.5% C and 13.2% G. This corresponds to a total A+T content of 56.3%, which is similar to that of other squamate lizard genomes.
Why neither diachronic universalism nor the Argument from Vagueness establishes perdurantism
Authors: Magidor Ofra
Published: April 2015

One of the most influential arguments in favour of perdurantism is the Argument from Vagueness. The argument proceeds in three stages: The first aims to establish atemporal universalism. The second presents a parallel argument in favour of universalism in the context of temporalized parthood (‘diachronic universalism’). The third argues that diachronic universalism entails perdurantism. I offer a novel objection to the argument. I show that on the correct way of formulating diachronic universalism the principle does not entail perdurantism. On the other hand, if diachronic universalism is formulated as Sider (incorrectly) proposes, the argument fails to establish his principle, and thus perdurantism.
The yeast ERAD-C ubiquitin ligase Doa10 recognizes an intramembrane degron
Authors: Habeck Gregor , Ebner Felix A. , Shimada-Kreft Hiroko , Kreft Stefan G.
Published: April 2015

Aberrant endoplasmic reticulum (ER) proteins are eliminated by ER-associated degradation (ERAD). This process involves protein retrotranslocation into the cytosol, ubiquitylation, and proteasomal degradation. ERAD substrates are classified into three categories based on the location of their degradation signal/degron: ERAD-L (lumen), ERAD-M (membrane), and ERAD-C (cytosol) substrates. In Saccharomyces cerevisiae, the membrane proteins Hrd1 and Doa10 are the predominant ERAD ubiquitin-protein ligases (E3s). The current notion is that ERAD-L and ERAD-M substrates are exclusively handled by Hrd1, whereas ERAD-C substrates are recognized by Doa10. In this paper, we identify the transmembrane (TM) protein Sec61 β-subunit homologue 2 (Sbh2) as a Doa10 substrate. Sbh2 is part of the trimeric Ssh1 complex involved in protein translocation. Unassembled Sbh2 is rapidly degraded in a Doa10-dependent manner. Intriguingly, the degron maps to the Sbh2 TM region. Thus, in contrast to the prevailing view, Doa10 (and presumably its human orthologue) has the capacity for recognizing intramembrane degrons, expanding its spectrum of substrates.
A combined coarse-grained and all-atom simulation of TRPV1 channel gating and heat activation
Authors: Zheng Wenjun , Qin Feng
Published: April 2015

The transient receptor potential (TRP) channels act as key sensors of various chemical and physical stimuli in eukaryotic cells. Despite years of study, the molecular mechanisms of TRP channel activation remain unclear. To elucidate the structural, dynamic, and energetic basis of gating in TRPV1 (a founding member of the TRPV subfamily), we performed coarse-grained modeling and all-atom molecular dynamics (MD) simulation based on the recently solved high resolution structures of the open and closed form of TRPV1. Our coarse-grained normal mode analysis captures two key modes of collective motions involved in the TRPV1 gating transition, featuring a quaternary twist motion of the transmembrane domains (TMDs) relative to the intracellular domains (ICDs). Our transition pathway modeling predicts a sequence of structural movements that propagate from the ICDs to the TMDs via key interface domains (including the membrane proximal domain and the C-terminal domain), leading to sequential opening of the selectivity filter followed by the lower gate in the channel pore (confirmed by modeling conformational changes induced by the activation of ICDs). The above findings of coarse-grained modeling are robust to perturbation by lipids. Finally, our MD simulation of the ICD identifies key residues that contribute differently to the nonpolar energy of the open and closed state, and these residues are predicted to control the temperature sensitivity of TRPV1 gating. These computational predictions offer new insights to the mechanism for heat activation of TRPV1 gating, and will guide our future electrophysiology and mutagenesis studies.
Ruling out pyridine dinucleotides as true TRPM2 channel activators reveals novel direct agonist ADP-ribose-2′-phosphate
Authors: Tóth Balázs , Iordanov Iordan , Csanády László
Published: April 2015

Transient receptor potential melastatin 2 (TRPM2), a Ca2+-permeable cation channel implicated in postischemic neuronal cell death, leukocyte activation, and insulin secretion, is activated by intracellular ADP ribose (ADPR). In addition, the pyridine dinucleotides nicotinamide-adenine-dinucleotide (NAD), nicotinic acid–adenine-dinucleotide (NAAD), and NAAD-2′-phosphate (NAADP) have been shown to activate TRPM2, or to enhance its activation by ADPR, when dialyzed into cells. The precise subset of nucleotides that act directly on the TRPM2 protein, however, is unknown. Here, we use a heterologously expressed, affinity-purified–specific ADPR hydrolase to purify commercial preparations of pyridine dinucleotides from substantial contaminations by ADPR or ADPR-2′-phosphate (ADPRP). Direct application of purified NAD, NAAD, or NAADP to the cytosolic face of TRPM2 channels in inside-out patches demonstrated that none of them stimulates gating, or affects channel activation by ADPR, indicating that none of these dinucleotides directly binds to TRPM2. Instead, our experiments identify for the first time ADPRP as a true direct TRPM2 agonist of potential biological interest.
Disparities in registration and use of an online patient portal among older adults: findings from the LitCog cohort
Authors: Smith Samuel G , O’Conor Rachel , Aitken William , Curtis Laura M , Wolf Michael S , Goel Mita Sanghavi
Published: April 2015

Objective To document disparities in registration and use of an online patient portal among older adults.

Materials and methods Data from 534 older adults were linked with information from the Northwestern Medicine Electronic Data Warehouse on patient portal registration and use of functions (secure messaging, prescription reauthorizations, checking test results, and monitoring vital statistics). Age, gender, race, education, self-reported chronic conditions, and the Newest Vital Sign health literacy measure were available from cohort data.

Results Most patients (93.4%) had a patient portal access code generated for them, and among these 57.5% registered their accounts. In multivariable analyses, White patients (P < .001) and college graduates were more likely to have registered their patient portal (P = .015). Patients with marginal (P = .034) or adequate (P < .001) health literacy were also more likely to have registered their patient portal. Among those registering their accounts, most had messaged their physician (90%), checked a test result (96%), and ordered a reauthorization (55%), but few monitored their vital statistics (11%). Adequate health literacy patients were more likely to have used the messaging function (P = .003) and White patients were more likely to have accessed test results (P = .004). Higher education was consistently associated with prescription reauthorization requests (all P < .05).

Discussion Among older American adults, there are stark health literacy, educational, and racial disparities in the registration, and subsequent use of an online patient portal. These population sub-group differences may exacerbate existing health disparities.

Conclusions If patient portals are implemented, intervention strategies are needed to monitor and reduce disparities in their use.
Screening of Wild and Cultivated Capsicum Germplasm Reveals New Sources of Verticillium Wilt Resistance
Authors: Gurung Suraj , Short Dylan P. G. , Hu Xiaoping , Sandoya German V. , Hayes Ryan J. , Subbarao Krishna V.
Published: April 2015

Verticillium wilt caused by Verticillium dahliae is an important soilborne disease of pepper (Capsicum species) worldwide. Most commercial pepper cultivars lack resistance to this pathogen. Our objective was to identify resistance to two V. dahliae isolates in wild and cultivated Capsicum accessions from the core collection of the National Plant Germplasm System of the USDA. Screening of 397 Capsicum accessions against two V. dahliae isolates (Vdca59 and VdCf45) was performed in a greenhouse. Seventy-eight accessions selected from this screen were further evaluated in a follow-up experiment. In total, 21 (26.9%) and 13 (16.6%) Capsicum accessions tested were resistant to Verticillium wilt when inoculated with V. dahliae isolates VdCa59 and VdCf45, respectively. Eight accessions (Grif 9073, PI 281396, PI 281397, PI 438666, PI 439292, PI 439297, PI 555616, and PI 594125) were resistant to Verticillium wilt against both V. dahliae isolates. On the basis of Germplasm Resources Information Network data, two of the Capsicum annuum accessions (Grif 9073 and PI 439297) were also resistant to Phytophthora root rot disease. These sources of multiple disease resistance will be useful to pepper breeding programs.
Portrayals of career women in Hollywood films: implications for the glass ceiling’s persistence
Authors: Ezzedeen Souha R.
Published: April 2015

Purpose

– The purpose of this study was to explore negative and stereotype-threatening depictions of career women in Hollywood films. The study draws on stereotype threat research to reflect on how such portrayals might undermine women’s career aspirations and contribute to the glass ceiling’s persistence, and proposes an agenda for future research.

Design/methodology/approach

– Bridging social role theories with conceptual models of films as social “texts”, the author explored depictions of 165 career women presented by 137 films, focusing on negative and potentially stereotype-threatening personal and professional characteristics and contexts.

Findings

– Thematic analyses of film portrayals revealed negative and stereotype-threatening characteristics and contexts of career women, including their mean and conniving personalities, promiscuity, isolation, failures at intimacy and inability to balance work and family.

Research limitations/implications

– Limitations include the subjective interpretations of a single author, a broad exploratory focus and no empirical evidence of connections between film portrayals and career attitudes. Researchers are encouraged to deepen analyses of film portrayals and examine linkages with stereotype threat and career behaviours sustaining the glass ceiling.

Practical implications

– Given the pervasive reach of the media and the potential for consumers to internalize its messages, the negative depictions documented here could bear an adverse effect on women’s career aspirations, contributing to the glass ceiling’s survival.

Originality/value

– Questioning the role of the media, in particular the portrayals of career women in film, provides an additional angle to understand why the glass ceiling endures.
Working from home and the gender gap in earnings for self-employed US Millennials
Authors: Simon Jessica , Way Megan McDonald
Published: April 2015

Purpose

– This paper aims to explore gender differences in terms of self-employment for US Millennials, relating them to working from home as well as other factors.

Design/methodology/approach

– The authors use a population-based survey, the National Longitudinal Survey of Youth 1997, which allows to compare home-based vs non-home-based self-employed women and men on a wide variety of characteristics. Descriptive analyses reveal the unconditional relationships between the covariates of interest, and the authors use ordinary least squares regression to reveal the conditional correlations between working from home and earnings for both women and men.

Findings

– The authors find that working from home is highly negatively correlated with earnings for women, but not for men, and that working from home may trump the other characteristics typically associated with lower earnings.

Research limitations/implications

– The regression subsample is relatively small (n = 245), leading to omitted variable bias in the regression. The “working-from-home” variable is potentially endogenous. The small sample size does not allow the authors to use detailed information on the self-employment industry. Future research should focus on finding larger samples and a way to instrument for working from home.

Social implications

– Work/life trends and communications technology have made working from home more prevalent (Mateyka et al., 2012). It is important for researchers and policymakers to understand the gendered implications of basing a business at home.

Originality/value

– The study is the first to use population-based data to focus specifically on gender gaps in earnings of self-employed Millennials in relation to working from home.
Performance implications of internationalization strategies for Chinese MNCs
Authors: Yuan Lin , Pangarkar Nitin
Published: April 2015

Purpose

– The purpose of this paper is to investigate the performance implications of internationalization strategies for Chinese multinational corporations (MNCs). Specifically, the authors examine the individual and joint effects of speed of internationalization in developed and developing countries and age on Chinese MNCs’ performance.

Design/methodology/approach

– The authors constructed a unique and comprehensive database on the internationalization strategies of 206 Chinese firms over 14 years and deployed random-effect regressions to assess the effects of age, speed of expansion in terms of number of subsidiaries and countries, and the types of destination (developed vs developing country) on firm performance.

Findings

– The analyses show that age is negatively related to performance but rapid expansion of subsidiaries in developing countries and geographic scope in developed countries are positively related to performance. In addition, the impacts of young age and two types of expansion, fast expansion of subsidiaries in developing countries and fast expansion of geographic scope in developed countries, are cumulative.

Originality/value

– The authors combine the arguments of the learning advantages of newness and fast movers and model the simultaneous effects of age and speed of two types of international expansion (in terms of number of subsidiaries and countries) in both developed and developing countries on performance. The strong empirical support for the hypotheses based on analyses of a unique data set of Chinese MNCs’ internationalization patterns lends credence to the proposed model.
Understanding solutions as technology-driven business innovations
Authors: Windahl Charlotta
Published: April 2015

Purpose

– This paper aims to provide a better understanding of the innovation challenges firms face when developing and commercialising solutions in the capital goods sector; challenges related to the interdependencies between the supplier/innovator and the customers, as well as the solution’s impact on their competencies and activities.

Design/methodology/approach

– This paper draws upon the emerging body of literature on solutions and established frameworks within innovation management literature. It explores a real-time longitudinal case study of “Alpha” (an international specialist in centrifugal separation, heat exchange and fluid handling), including an R&D project, the project’s transformation into an internal corporate venture and the years of the venture up until its integration into the corporate.

Findings

– This paper characterises solutions as involving product and business innovation. By clarifying the differences between how the solution affects the customers and the suppliers, the use of the proposed framework develops a deeper understanding of the obstacles and difficulties involved in solution innovation.

Research limitations/implications

– Although some customers were interviewed in this study, a more in-depth study of the customers and the actors within the business network would provide further insight into solution innovations. Merging the two discussions on co-creation and role of users in innovation could provide an avenue for fruitful research within this area.

Practical implications

– This paper provides a framework for deconstructing solution innovation, enabling detailed comparison between the innovation’s impact on both suppliers’ and customer’s competencies. Such a tool is helpful for increased understanding of how to facilitate internal and external acceptance for a disruptive and radical business innovation.

Originality/value

– This paper links the development and commercialisation of solutions with established innovation frameworks. Understanding solutions as technology-driven business innovations provides a multifaceted and complex perspective on solutions and contributes to better understanding of radical business innovations.
Measuring strategic performance in construction companies: a proposed integrated model
Authors: Oyewobi Luqman Oyekunle , Windapo Abimbola Olukemi , Rotimi James Olabode B.
Published: April 2015

Purpose

– This paper aims to examine and compare a performance measurement system and performance frameworks commonly used within the construction industry. The paper explores the strengths and weaknesses of balanced scorecard (BSC) and business excellence model (BEM) to propose an integrated model for measuring strategic performance of construction organisations as a single model. The purpose is to help organisations achieve performance excellence, financial integrity and continuous improvement in business results to sustain competitive advantage.

Design/methodology/approach

– This paper examines and compares performance measurement system and performance frameworks commonly used within the construction industry. The paper explores the strengths and weaknesses of BSC and BEM to propose an integrated model for measuring strategic performance of construction organisations as a single model. The purpose is to help organisations achieve performance excellence, financial integrity and continuous improvement in business results to sustain competitive advantage.

Findings

– The study reveals that the most popular performance measurement framework in construction includes: BSC; Key Performance Indicators and European Foundation for Quality Management. However, literature also reveals that Malcolm Baldrige National Quality Award is being used to measure performance in the construction. The study findings indicated that BSC and BEM could be combined to provide an integrated model that will encompass every facet of construction performance measures.

Research limitations/implications

– The paper integrates the BSC and BEM performance measurement models, to provide construction organisations the opportunities of benefitting from the two models as a single tool without having to use more than one model or miss out any important aspect of performance measures. The model will assist organisations perform regular health checks of all business process and at the same time help align organisational activities with strategic primacy.

Practical implications

– The paper offers an integrated construction excellence model as a useful tool for measuring both financial and non-financial performance aspects of construction organisations. This will provide managers, owners and other stakeholders the chance of measuring processes and pre-eminent strategic initiatives using a single model.

Originality/value

– The conceptual paper presents an integration of processes and perspectives for measuring performance as a new and useful tool in the context of the South African construction industry. The paper suggests that research efforts should be directed on how to implement the strategic performance model efficiently within a specific construction environment.
Improving learning outcome using Six Sigma methodology
Authors: Tetteh Godson A.
Published: April 2015

Purpose

– The purpose of this research paper is to apply the Six Sigma methodology to identify the attributes of a lecturer that will help improve a student’s prior knowledge of a discipline from an initial “x” per cent knowledge to a higher “y” per cent of knowledge.

Design/methodology/approach

– The data collection method involved a one-on-one, in-depth interview based on the Kano questionnaire with a sample of 170 undergraduate and graduate students aged between 25 and 40 years in two Ghanaian universities. The Kano questionnaire contained the critical to quality (CTQ) and the 25 functional requirements (FRs). The analytical Kano (A-Kano) questionnaire was adopted for the purpose of improving learning outcome with a student–lecturer interaction. The CTQs in this study, from the customer (student) perspective, will correspond to Bloom’s (1956) categories in the cognitive domain made up of remember, understand, apply, analyze, evaluate and create. The configuration index, which provides a decision factor for selecting the 25 FRs that contribute to improving learning outcome made up of the American Society of Quality’s six leadership competencies (navigator, communicator, mentor, learner, builder and motivator) and 19 attributes from previous research studies on service quality in higher education. This study used the varimax and quartimax factor analysis rotation methods to generate the principal components (PCs).

Findings

– Out of the 25 FRs, four (communicator, mentor, builder and motivator) of the American Society of Quality (ASQ) leadership competencies were found to be exciters or attractive and when applied by the lecturer would exceed customer (student) expectation.

Research limitations/implications

– The study involved only a judgment sample of 170 undergraduate and graduate students from two universities drawn in Accra, Ghana; hence, the outcome cannot be generalized to the entire student population in Ghana as a whole.

Practical implications

– The Kano results from this study corroborates with previous findings that students perceive “Fostering of Team Work”, “Expertise in Other Subject Areas”, “Variety of Teaching Methods”, “Friendliness” and “Humor” as either exciters or attractive attributes.

Social implications

– Some of the benefits from this study include the fact that lecturers may improve classroom experience knowing what their students regard as satisfactory and dissatisfactory attributes or they may have a better understanding of the student’s perspective. The concept of student satisfaction addressed in this study should therefore always be seen as a “means to an end”, with the end being the transformation of students.

Originality/value

– This study contributes to the literature by examining how the student’s approach to learning or acquiring new knowledge has a significant effect on the learning outcome using factor analysis rotation methods to generate the PCs.
Transforming library communication: from Gutenberg to Zuckerberg
Authors: Einasto Olga
Published: April 2015

Purpose

– The purpose of this paper is to analyse institutional and functional development of a library with the help of communication theories. The library as a social institution should have a quite strong position in today’s information society, but new ways of information search have made its position unstable. Thus, a library needs theoretical and cultural-political comprehension and reassessment. The paper tries to answer the questions as to how a library can satisfy the needs of modern society and which strategy of library communication will be in demand tomorrow.

Design/methodology/approach

– The theoretical background is represented by communication theories of Marshal McLuhan, Denis McQuail and Yuri Lotman, as well as Michel Foucault’s concepts of disciplinary power and governmentality.

Findings

– The analysis revealed that library–user communication is based primarily on power relations, where “access” is the main keyword. The article brought out differences in library communicative processes in the “Gutenberg Galaxy” and today’s global network society, “Zuckerberg Era”. The analysis showed that library–user relationship is shifting from disciplinary power and monologue to the governmentality and new communicative forms, dialogue and participation.

Research limitations/implications

– The study demonstrates the possibility of implication of communication theories for library functional analysis. The new studies investigating which methods and forms of communication do libraries use today, how are the elements of power relations transforming would be very useful for the understanding of the topic.

Practical implications

– The study proposes to libraries some ideas that may be useful for developing the library communication strategy.

Originality/value

– This study, based on the communicative approach, corresponds well to library phenomenon and nature, as well as allows for reflection on the role of libraries in the society of today and future.
Engaging international students in academic and information literacy
Authors: Lahlafi Alison , Rushton Diane
Published: April 2015

Purpose

– The purpose of this paper is to discuss a collaborative initiative between a module leader, librarian and academic skills tutor to support information and academic literacy skills development of a group of international students from a partner college in Malaysia during their three-month study visit to Sheffield Hallam University.

Design/methodology/approach

– The paper explores the transferability of active learning and teaching techniques used with second-year home students to a cohort of final-year international students. It discusses the development, implementation and assessment of learning workshop activities and the use of mobile phones in the classroom to enhance student engagement.

Findings

– The embedded active learning and teaching techniques used with second-year home students transferred well to the international student cohort. At the end of the module, international student feedback and reference list analysis suggests that the embedding of both information and academic literacy skills within modules does support student development of these skills. Mobile technology proved both enjoyable and engaging for the students.

Originality/value

– The paper’s findings are transferable to other international student cohorts in UK higher education libraries and suggest ways of engaging students in information and academic skills workshops and supporting their skills development to achieve academic success.
Creating policies for library publishing in an institutional repository
Authors: Riddle Kelly
Published: April 2015

Purpose

– This paper aims to explore questions and concepts encountered when developing policies for an institutional repository with a library publishing component.

Design/methodology/approach

– The author describes how publishing needs and library vision shape institutional repository policies, and demonstrates that the repository’s guiding policies are determined by the repository’s purpose and scope.

Findings

– Policies for institutional repositories with publishing components will vary across institutions depending on the intended purpose of the repository, scope of publishing activities and institutional context.

Originality/value

– The article is useful for those just exploring library publishing with repositories and those looking to revamp their policies to accommodate this new use, the paper explores theoretical and practical questions about this new use of repositories.