bluuebunny/crossref_metadata_2025 huggingface dataset:
Numerical analysis of electrostatic ion cyclotron instability in an electron-positron-ion plasma
Authors: Khorashadizadeh S. M. , Barati Moqadam Niyat M. , Niknam A. R.
Published: June 2016

This paper presents a theoretical study of the effects of positron density on the electrostatic ion cyclotron instability in an electron-positron-ion plasma using the kinetic theory approach. It is supposed that positrons and electrons can drift parallel to the magnetic field either in the same or the opposite directions. The dispersion relation for the electrostatic ion cyclotron waves in an electron-positron-ion plasma is derived, and the numerical results are investigated. It is found that an increase in positron concentration increases the critical drift velocity for excitation of the instability in both configurations. It is also found that as the positron concentration increases the growth rate of instability decreases. In addition, it is shown that at low velocities the maximum instability growth rate for the unidirectional case is higher than the counter-streaming case; however, after a certain velocity, the maximum growth rate in the counter-streaming case dominates that of the unidirectional case.
Reduction of furnace temperature in ultra long carbon nanotube growth by plasmonic excitation of electron Fermi gas of catalytic nanocluster
Authors: Saeidi Mohammadreza
Published: June 2016

In this paper, a novel physical method is presented to reduce the temperature of the furnace and prevent loss of thermal energy in ultra long carbon nanotube (CNT) growth process by catalytic chemical vapor deposition. This method is based on the plasmonic excitation of electron Fermi gas of catalytic nanocluster sitting at tip end of CNT by ultraviolet (UV) irradiation. Physical concepts of the method are explained in detail. The results of applying the presented method consequences to an appropriate tip-growth mechanism of the ultra long CNTs show that, in the presence of plasmonic excitation, the growth rate of the CNT is enhanced. Demonstration of temperature reduction and simultaneous increase in CNT length by UV irradiation with the proper frequency are the most important and practical result of the paper. All results are interpreted and discussed.
Weakly relativistic electromagnetic solitons in warm plasmas
Authors: Sundar Sita
Published: June 2016

For slowly propagating electromagnetic solitons, validity of the cold plasma model is addressed using a more realistic model involving effects arising due to temperature as well as ion dynamics. Small amplitude single peak structures which are quasineutral are studied, and different regions of existence of bright and dark classes of solitons are delineated. Influence of temperature on spectral characteristics of the solitary structures is presented.
Modeling of the merging of two colliding field reversed configuration plasmoids
Authors: Wang Guanqiong , Wang Xiaoguang , Li Lulu , Yang Xianjun
Published: June 2016

The field reversed configuration (FRC) is one of the candidate plasma targets for the magneto-inertial fusion, and a high temperature FRC can be formed by using the collision-merging technology. Although the merging process and mechanism of FRC are quite complicated, it is thinkable to build a simple model to investigate the macroscopic equilibrium parameters including the density, the temperature and the separatrix volume, which may play an important role in the collision-merging process of FRC. It is quite interesting that the estimates of the related results based on our simple model are in agreement with the simulation results of a two-dimensional magneto-hydrodynamic code (MFP-2D), which has being developed by our group since the last couple of years, while these results can qualitatively fit the results of C-2 experiments by Tri-alpha energy company. On the other hand, the simple model can be used to investigate how to increase the density of the merged FRC. It is found that the amplification of the density depends on the poloidal flux-increase factor and the temperature increases with the translation speed of two plasmoids.
A gas circulation and purification system for gas-cell-based low-energy RI-beam production
Authors: Sonoda T. , Tsubota T. , Wada M. , Katayama I. , Kojima T. M. , Reponen M.
Published: June 2016

A gas circulation and purification system was developed at the RIKEN Radioactive Isotope Beam Factory that can be used for gas-cell-based low-energy RI-beam production. A high-flow-rate gas cell filled with one atmosphere of buffer gas (argon or helium) is used for the deceleration and thermalization of high-energy RI-beams. The exhausted buffer gas is efficiently collected using a compact dry pump and returned to the gas cell with a recovery efficiency of >97%. The buffer gas is efficiently purified using two gas purifiers as well as collision cleaning, which eliminates impurities in the gas. An impurity level of one part per billion is achieved with this method.
Thermally activated hysteresis in high quality graphene/h-BN devices
Authors: Cadore A. R. , Mania E. , Watanabe K. , Taniguchi T. , Lacerda R. G. , Campos L. C.
Published: June 2016

We report on gate hysteresis of resistance in high quality graphene/hexagonal boron nitride (h-BN) devices. We observe a thermally activated hysteretic behavior in resistance as a function of the applied gate voltage at temperatures above 375 K. In order to investigate the origin of the hysteretic phenomenon, we compare graphene/h-BN heterostructure devices with SiO2/Si back gate electrodes to devices with graphite back gate electrodes. The gate hysteretic behavior of the resistance is present only in devices with an h-BN/SiO2 interface and is dependent on the orientation of the applied gate electric field and sweep rate. We describe a phenomenological model which captures all of our findings based on charges trapped at the h-BN/SiO2 interface. Such hysteretic behavior in graphene resistance must be considered in high temperature applications for graphene devices and may open new routes for applications in digital electronics and memory devices.
Density-functional description of polymer crystals: A comparative study of recent van der Waals functionals
Authors: Pham Thinh H. , Ramprasad Rampi , Nguyen Huy-Viet
Published: June 2016

Due to the lack of treatment of long-range dispersion energies, density functional theory with local and semilocal approximations of exchange-correlation energy is known to fail in describing van der Waals complexes, including polymer crystals. This limitation can be overcome by using a different class of functionals, called van der Waals density functional (vdW-DF), originally developed by Dion et al. [Phys. Rev. Lett. 92, 246401 (2004)]. In this work, we performed a systematic study of structural properties of polymeric crystals using the original vdW-DF functional by Dion et al. and its variants and refinements. Our study shows that this class of functional outperforms the conventional LDA or PBE functionals and gives results with similar accuracy to that of empirical dispersion-corrected schemes such as DFT-D. This study suggests the use of vdW-DF2 functional — a revised version of vdW-DF functional — to obtain a high-fidelity prediction of structural and other properties of polymeric materials.
Sub-nanosecond threshold-switching dynamics and set process of In3SbTe2 phase-change memory devices
Authors: Pandey Shivendra Kumar , Manivannan Anbarasu
Published: June 2016

Phase-change materials show promising features for high-speed, non-volatile, random access memory, however achieving a fast electrical switching is a key challenge. We report here, the dependence of electrical switching dynamics including transient parameters such as delay time, switching time, etc., on the applied voltage and the set process of In3SbTe2 phase-change memory devices at the picosecond (ps) timescale. These devices are found to exhibit threshold-switching at a critical voltage called threshold-voltage, VT of 1.9 ± 0.1 V, having a delay time of 25 ns. Further, the delay time decreases exponentially to a remarkably smaller value, as short as 300 ± 50 ps upon increasing the applied voltage up to 1.1VT. Furthermore, we demonstrate a rapid phase-change behavior from amorphous (∼10 MΩ) to poly-crystalline (∼10 kΩ) phase using time-resolved measurements revealing an ultrafast set process, which is primarily initiated by the threshold-switching process within 550 ps for an applied voltage pulse with a pulse-width of 1.5 ns and an amplitude of 2.3 V.
High performance p-type NiOx thin-film transistor by Sn doping
Authors: Lin Tengda , Li Xiuling , Jang Jin
Published: June 2016

Major obstacles towards power efficient complementary electronics employing oxide thin-film transistors (TFTs) lie in the lack of equivalent well performing p-channel devices. Here, we report a significant performance enhancement of solution-processed p-type nickel oxide (NiOx) TFTs by introducing Sn dopant. The Sn-doped NiOx (Sn-NiOx) TFTs annealed at 280 °C demonstrate substantially improved electrical performances with the increase in the on/off current ratio (Ion/Ioff) by ∼100 times, field-effect mobility (μlin) by ∼3 times, and the decrease in subthreshold swing by half, comparing with those of pristine NiOx TFTs. X-ray photoelectron spectroscopy and X-ray diffraction results confirm that Sn atoms tend to substitute Ni sites and induce more amorphous phase. A decrease in density of states in the gap of NiOx by Sn doping and the shift of Fermi level (EF) into the midgap lead to the improvements of TFT performances. As a result, Sn-NiOx can be a promising material for the next-generation, oxide-based electronics.
Ballistic conductivity of graphene channel with p-n junction at ferroelectric domain wall
Authors: Morozovska Anna N. , Eliseev Eugene A. , Strikha Maksym V.
Published: June 2016

The influence of a ferroelectric domain wall on the ballistic conductance of a single-layer graphene channel in the graphene/physical gap/ferroelectric film heterostructure has been studied in the Wentzel-Kramers-Brillouin approximation. The self-consistent numerical simulation of the electric field and the space charge dynamics in the heterostructure, as well as the approximate analytical theory, show that the contact between the domain wall and the surface creates a p-n junction in the graphene channel. We calculated that the carrier concentration induced in graphene by uncompensated ferroelectric dipoles originated from the abrupt spontaneous polarization change near the surface can reach values of about 1019 m−2, which are two orders of magnitude higher than those obtained for the graphene on non-ferroelectric substrates. Therefore, we predict that the graphene channel with the p-n junction caused by the ferroelectric domain wall would be characterized by rather a high ballistic conductivity. Moreover, the graphene p-n junction at the ferroelectric domain wall can be an excellent rectifier with a conductivity ratio of about 10 between the direct and reverse polarities of the applied voltage.
Low-noise epitaxial graphene on SiC Hall effect element for commercial applications
Authors: Ciuk Tymoteusz , Petruk Oleg , Kowalik Andrzej , Jozwik Iwona , Rychter Andrzej , Szmidt Jan , Strupinski Wlodzimierz
Published: June 2016

In this report, we demonstrate a complete Hall effect element that is based on quasi-free-standing monolayer graphene synthesized on a semi-insulating on-axis Si-terminated 6H-SiC substrate in an epitaxial Chemical Vapor Deposition process. The device offers the current-mode sensitivity of 87 V/AT and low excess noise (Hooge's parameter αH < 2 × 10−3) enabling room-temperature magnetic resolution of 650 nT/Hz0.5 at 10 Hz, 95 nT/Hz0.5 at 1 kHz, and 14 nT/Hz0.5 at 100 kHz at the total active area of 0.1275 mm2. The element is passivated with a silicone encapsulant to ensure its electrical stability and environmental resistance. Its processing cycle is suitable for large-scale commercial production and it is available in large quantities through a single growth run on an up to 4-in SiC wafer.
Magneto-transport analysis of an ultra-low-density two-dimensional hole gas in an undoped strained Ge/SiGe heterostructure
Authors: Laroche D. , Huang S.-H. , Chuang Y. , Li J.-Y. , Liu C. W. , Lu T. M.
Published: June 2016

We report the magneto-transport, scattering mechanisms, and effective mass analysis of an ultra-low density two-dimensional hole gas capacitively induced in an undoped strained Ge/Si0.2Ge0.8 heterostructure. This fabrication technique allows hole densities as low as p ∼ 1.1 × 1010 cm−2 to be achieved, more than one order of magnitude lower than previously reported in doped Ge/SiGe heterostructures. The power-law exponent of the electron mobility versus density curve, μ ∝ nα, is found to be α ∼ 0.29 over most of the density range, implying that background impurity scattering is the dominant scattering mechanism at intermediate densities in such devices. A charge migration model is used to explain the mobility decrease at the highest achievable densities. The hole effective mass is deduced from the temperature dependence of Shubnikov-de Haas oscillations. At p ∼ 1.0 × 1011 cm−2, the effective mass m* is ∼0.105 m0, which is significantly larger than masses obtained from modulation-doped Ge/SiGe two-dimensional hole gases.
Investigating the origin of efficiency droop by profiling the voltage across the multi-quantum well of an operating light-emitting diode
Authors: Kim Taewoong , Seong Tae-Yeon , Kwon Ohmyoung
Published: June 2016

Efficiency droop is a phenomenon in which the efficiency of a light-emitting diode (LED) decreases with the increase in current density. To analyze efficiency droop, direct experimental observations on the energy conversion occurring inside the LED is required. Here, we present the measured voltage profiles on the cross section of an operating LED and analyze them with the cross-sectional temperature profiles obtained in a previous study under the same operation conditions. The measured voltage profiles suggest that with increases in the injection current density, electron depletion shifts from the multi-quantum well through an electron blocking layer to the p-GaN region. This is because electron leakage increases with increases in current density.
Transport and deceleration of fusion products in microturbulence
Authors: Wilkie George J. , Abel Ian G. , Landreman Matt , Dorland William
Published: June 2016

The velocity-space distribution of alpha particles born in fusion devices is subject to modification at moderate energies due to turbulent transport. Therefore, one must calculate the evolution of an equilibrium distribution whose functional form is not known a priori. Using a novel technique, applicable to any trace impurity, we have made this calculation for fully nonlinear gyrokinetic simulations not only possible but also particularly efficient. We demonstrate a microturbulence-induced departure from the local slowing-down distribution, an inversion of the energy distribution, and associated modifications to the alpha heating and pressure profiles in an ITER-like scenario.
Experimental observation of turbulence transition and a critical gradient threshold for trapped electron mode in tokamak plasmas
Authors: Zhong W. L. , Shi Z. B. , Yang Z. J. , Xiao G. L. , Yang Z. C. , Zhang B. Y. , Shi P. W. , Du H. R. , Pan X. M. , Zhou R. B. , Wan L. H. , Zou X. L. , Xu M. , Duan X. R. , Liu Yong , Zhuang G. ,   HL-2A Team,   J-TEXT Team
Published: June 2016

In HL-2A and J-TEXT ohmic confinement regimes, an electrostatic turbulence with quasi-coherent characteristics in spectra of density fluctuations was observed by multi-channel microwave reflectometers. These quasi-coherent modes (QCMs) were detectable in a large plasma region (r/a∼0.3−0.8). The characteristic frequencies of QCMs were in the range of 30–140 kHz. The mode is rotated in the electron diamagnetic direction. In the plasmas with QCMs, trapped electron mode (TEM) was predicted to be unstable by gyrokinetic simulations. The combined experimental results show that the TEM is survived in the linear ohmic confinement regime of plasmas. The quasi-coherent TEM was replaced by broad-band fluctuations when the plasma transits from linear to saturated ohmic confinement regime. The observation was strongly related to the turbulence transition from TEM to ion temperature gradient mode. A critical gradient threshold for TEM excitation in electron temperature gradient was directly found. The effect of TEM on density profile peaking was presented.
Multiple lobes in the far-field distribution of terahertz quantum-cascade lasers due to self-interference
Authors: Röben B. , Wienold M. , Schrottke L. , Grahn H. T.
Published: June 2016

The far-field distribution of the emission intensity of terahertz (THz) quantum-cascade lasers (QCLs) frequently exhibits multiple lobes instead of a single-lobed Gaussian distribution. We show that such multiple lobes can result from self-interference related to the typically large beam divergence of THz QCLs and the presence of an inevitable cryogenic operation environment including optical windows. We develop a quantitative model to reproduce the multiple lobes. We also demonstrate how a single-lobed far-field distribution can be achieved.
Toward error-free scaled spin torque majority gates
Authors: Vaysset Adrien , Manfrini Mauricio , Nikonov Dmitri E. , Manipatruni Sasikanth , Young Ian A. , Pourtois Geoffrey , Radu Iuliana P. , Thean Aaron
Published: June 2016

The functionality of a cross-shaped Spin Torque Majority Gate is explored by means of micromagnetic simulations. The different input combinations are simulated varying material parameters, current density and size. The main failure mode is identified: above a critical size, a domain wall can be pinned at the center of the cross, preventing further propagation of the information. By simulating several phase diagrams, the key parameters are obtained and the operating condition is deduced. A simple relation between the domain wall width and the size of the Spin Torque Majority Gate determines the working range. Finally, a correlation is found between the energy landscape and the main failure mode. We demonstrate that a macrospin behavior ensures a reliable majority gate operation.
Development of Lignocellulosic Biorefinery Technologies: Recent Advances and Current Challenges
Authors: Amore Antonella , Ciesielski Peter N. , Lin Chien-Yuan , Salvachúa Davinia , Sànchez i Nogué Violeta
Published: June 2016

Recent developments of the biorefinery concept are described within this review, which focuses on the efforts required to make the lignocellulosic biorefinery a sustainable and economically viable reality. Despite the major research and development endeavours directed towards this goal over the past several decades, the integrated production of biofuel and other bio-based products still needs to be optimized from both technical and economical perspectives. This review will highlight recent progress towards the optimization of the major biorefinery processes, including biomass pretreatment and fractionation, saccharification of sugars, and conversion of sugars and lignin into fuels and chemical precursors. In addition, advances in genetic modification of biomass structure and composition for the purpose of enhancing the efficacy of conversion processes, which is emerging as a powerful tool for tailoring biomass fated for the biorefinery, will be overviewed. The continual improvement of these processes and their integration in the format of a modern biorefinery is paving the way for a sustainable bio-economy which will displace large portions of petroleum-derived fuels and chemicals with renewable substitutes.
Cetacean diversity, common occurrence and community importance in Fijian waters
Authors: Miller Cara , Batibasaga Aisake , Chand Prerna , Dulunaqio Sirilo , Fox Margaret , Jupiter Stacy , Naisilisili Waisea , Nand Yashika , Sharma-Gounder Saras , Smith Brian
Published: June 2016

Fiji has demonstrated a strong commitment to cetacean conservation via national, regional and international plans and agreements. To provide baseline information in support of these efforts, this paper provides an updated listing of cetacean species found in Fijian waters and identifies locations where cetaceans have been noted on a consistent basis. Information for this review was sourced from peer-reviewed publications, field reports, historical whaling records, national consultations, anecdotal and opportunistic sources, as well as a national database held by the Fiji Government’s Department of Fisheries. Reliable and recent records were confirmed for 10 cetacean species in Fijian waters. In addition, less reliable records and regional species’ information provides support for the occurrence of at least 14 additional species or groups of similar-looking species that could not be identified more specifically. Thirteen hotspot areas within the Fiji Economic Exclusive Zone were preliminarily identified as being particularly important for cetaceans, including numerous sites within the Vatu-i-Ra and Lomaiviti passages and surrounding waters. Issues with the available data include uneven coverage, inherent biases within available sources, and difficulties with species identification and verification in some cases. Nevertheless, it is hoped that this review will provide a reference point from which to move forward with cetacean management and conservation efforts in Fiji.
High glucose levels affect spermatogenesis: an in vitro approach
Authors: Tavares Renata S. , Portela Joana M. D. , Sousa Maria I. , Mota Paula C. , Ramalho-Santos João , Amaral Sandra
Published: June 2016

Besides known factors that may cause male infertility, systemic diseases such as diabetes mellitus may further exacerbate a decline in male fertility. This metabolic disease, clinically characterised by a hyperglycaemic phenotype, has devastating consequences in terms of human health, with reproductive dysfunction being one of the associated clinical complications. Nonetheless, the mechanisms responsible for such alterations are still poorly understood due to the multiplicity of factors involved in the induced pathophysiological changes. With this in mind, we focused on the main mediator of diabetes-associated alterations and performed an in vitro approach to address the effects of high glucose conditions on spermatogenesis, avoiding other confounding in vivo factors. Mouse (5 days post partum) testis fragments were cultured on agar gel stands at a gas–liquid interface with either 5, 25 or 50 mM D-glucose for 3 weeks. Stereological analysis revealed that high D-glucose levels increased Sertoli cell number (P < 0.05) and decreased tubular luminal area (P < 0.01), suggesting an impairment of this somatic cell type. Moreover, higher proliferative activity in a TM4 Sertoli cell line exposed to high D-glucose was found (P < 0.05) without compromising cell viability (P > 0.05), further suggesting altered Sertoli cell maturation. Overall, high D-glucose concentrations may lead to impairment of Sertoli cell function, which, given their significant role in spermatogenic control, may compromise male fertility.
How inhibitory cues can both constrain and promote cell migration
Authors: Bronner Marianne E.
Published: June 2016

Collective cell migration is a common feature in both embryogenesis and metastasis. By coupling studies of neural crest migration in vivo and in vitro with mathematical modeling, Szabó et al. (2016, J. Cell Biol., http://dx.doi.org/10.1083/jcb.201602083) demonstrate that the proteoglycan versican forms a physical boundary that constrains neural crest cells to discrete streams, in turn facilitating their migration.
Fred Chang: The shape of things to come
Authors: Jordan Shawn
Published: June 2016

Chang’s work focuses on how cells sense and control their shape and size.
Anti-TNF drives regulatory T cell expansion by paradoxically promoting membrane TNF–TNF-RII binding in rheumatoid arthritis
Authors: Nguyen Dao Xuan , Ehrenstein Michael R.
Published: June 2016

The interplay between inflammatory and regulatory pathways orchestrates an effective immune response that provides protection from pathogens while limiting injury to host tissue. Tumor necrosis factor (TNF) is a pivotal inflammatory cytokine, but there is conflicting evidence as to whether it boosts or inhibits regulatory T cells (T reg cells). In this study, we show that the therapeutic anti-TNF antibody adalimumab, but not the soluble TNF receptor etanercept, paradoxically promoted the interaction between monocytes and T reg cells isolated from patients with rheumatoid arthritis (RA). Adalimumab bound to monocyte membrane TNF from RA patients and unexpectedly enhanced its expression and its binding to TNF-RII expressed on T reg cells. As a consequence, adalimumab expanded functional Foxp3+ T reg cells equipped to suppress Th17 cells through an IL-2/STAT5-dependent mechanism. Our data not only highlight the beneficial effect of membrane TNF on T reg cell numbers during chronic inflammation, but in addition reveal how a therapeutic antibody that is thought to act by simply blocking its target can enhance the regulatory properties of this proinflammatory cytokine.
An unusual case of seronegative, 16S PCR positive Brucella infection
Authors: Bharathan Binutha , Backhouse Lucy , Rawat David , Naik Sandhia , Millar Michael
Published: June 2016

Introduction:

Brucella is a zoonotic infection commonly diagnosed by isolation of the organism from blood culture or positive serological testing. It is an uncommon cause of a pyrexia of unknown origin in the United Kingdom.

Case presentation:

We describe the case of a 14-year-old girl with no history of travel who presented with pyrexia, weight loss, arthralgia, multiple splenic abscesses and a subsequent pleural effusion, the latter of which isolated a Brucella species on 16S rRNA PCR. The patient responded well to initiation of treatment for brucellosis and on repeat imaging, after 3 months, the splenic abscesses had resolved.

Conclusion:

This unique case demonstrates uncommon complications of brucellosis and the challenges of diagnosing the organism, the latter of which can be alleviated by the utilization of molecularbased technologies. This patient had a negative serology result for brucellosis, which highlights the need to interpret serology results with caution in non-endemic regions for brucellosis.
KIF1A/UNC-104 transports ATG-9 to regulate neurodevelopment and autophagy at synapses
Authors: Stavoe Andrea K. H. , Hill Sarah E. , Colón-Ramos Daniel A.
Published: June 2016

Autophagy is a cellular degradation process essential for neuronal development and survival. Neurons are highly polarized cells in which autophagosome biogenesis is spatially compartmentalized. The mechanisms and physiological importance of this spatial compartmentalization of autophagy in the neuronal development of living animals are not well understood. Here we determine that, inC. elegansneurons, autophagosomes form near synapses and are required for neurodevelopment. We first determined, through unbiased genetic screens and systematic genetic analyses, that autophagy is required cell-autonomously for presynaptic assembly and for axon outgrowth dynamics in specific neurons. We observe autophagosomes in the axon near synapses, and this localization depends on the synaptic vesicle kinesin, KIF1A/UNC-104. KIF1A/UNC-104 coordinates localized autophagosome formation by regulating the transport of the integral membrane autophagy protein, ATG-9. Our findings indicate that autophagy is spatially regulated in neurons through the transport of ATG-9 by KIF1A/UNC-104 to regulate neurodevelopment.
Fungal Induced Protein Hyperacetylation Identified by Acetylome Profiling
Authors: Walley Justin W , Shen Zhouxin , McReynolds Maxwell R. , Briggs Steven P.
Published: June 2016

Lysine acetylation is a key post-translational modification that regulates diverse proteins involved in a range of biological processes. The role of histone acetylation in plant defense is well established and it is known that pathogen effector proteins encoding acetyltransferses can directly acetylate host proteins to alter immunity. However, it is unclear whether endogenous plant enzymes can modulate protein acetylation during an immune response. Here we investigate how the effector molecule HC-toxin, a histone deacetylase inhibitor, produced byCochliobolus carbonumrace 1 promotes pathogen virulence in maize through altering protein acetylation. Using mass spectrometry we globally quantified the abundance of 3,636 proteins and the levels of acetylation at 2,791 sites in maize plants treated with HC-toxin as well as HC-toxin deficient or producing strains ofC. carbonum.Analyses of these data demonstrate that acetylation is a widespread post-translational modification impacting proteins encoded by many intensively studied maize genes. Furthermore, the application of exogenous HC-toxin enabled us to show that the activity of plant-encoded enzymes can be modulated to alter acetylation of non-histone proteins during an immune response. Collectively, these results provide a resource for further mechanistic studies examining the regulation of protein function and offer insight into the complex immune response triggered by virulentC. carbonum.
Playing Musical Chairs in Big Data to Reveal Variables’ Associations
Authors: Aschard Hugues , Vilhjalmsson Bjarni , Patel Chirag , Skurnik David , Yu Jimmy , Wolpin Brian , Kraft Peter , Zaitlen Noah
Published: June 2016

Testing for associations in big data faces the problem of multiple comparisons, with true signals buried inside the noise of all associations queried. This is particularly true in genetic association studies where a substantial proportion of the variation of human phenotypes is driven by numerous genetic variants of small effect. The current strategy to improve power to identify these weak associations consists of applying standard marginal statistical approaches and increasing study sample sizes. While successful, this approach does not leverage the environmental and genetic factors shared between the multiple phenotypes collected in contemporary cohorts. Here we develop a method that improves the power of detecting associations when a large number of correlated variables have been measured on the same samples. Our analyses over real and simulated data provide direct support that large sets of correlated variables can be leveraged to achieve dramatic increases in statistical power equivalent to a two or even three folds increase in sample size.
Deleterious variants in Asian rice and the potential cost of domestication
Authors: Liu Qingpo , Zhou Yongfeng , Morrell Peter L. , Gaut Brandon S.
Published: June 2016

Many SNPs are predicted to encode deleterious amino acid variants. These slightly deleterious mutations can provide unique insights into population history, the dynamics of selection, and the genetic bases of phenotypes. This is especially true for domesticated species, where a history of bottlenecks and selection may affect the frequency of deleterious variants and signal a ‘cost of domestication’. Here we investigated the numbers and frequencies of deleterious variants in Asian rice (O. sativa), focusing on two varieties (japonicaandindica)and their wild relative (O. rufipogon). We investigated three signals of a potential cost of domestication in Asian rice relative toO. rufipogon: an increase in the frequency of deleterious SNPs (dSNPs), an enrichment of dSNPs compared to synonymous SNPs (sSNPs), and an increased number of deleterious variants. We found evidence for all three signals, and domesticated individuals contained ~3-4% more deleterious alleles than wild individuals. Deleterious variants were enriched within low recombination regions of the genome and experienced frequency increases similar to sSNPs within regions of putative selective sweeps. A characteristic feature of rice domestication was a shift in mating system from outcrossing to predominantly selfing. Forward simulations suggest that this shift in mating system may have been the dominant factor in shaping both deleterious and neutral diversity in rice.
Role of management accounting in applying new institutional logics
Authors: Järvinen Janne T.
Published: June 2016

Purpose

– The purpose of this paper is to explore the adoption of management accounting and control systems in the non-profit sector.

Design/methodology/approach

– The theoretical framework of this comparative interpretative study draws on new institutional theory, especially the concepts of institutional logics and institutional work.

Findings

– New accounting and management controls serve as a medium through which organizations negotiate between multiple and conflicting objectives and choose institutional logics in the organizational field.

Research limitations/implications

– The data comprise interviews, observations and archival data and provides a limited view on how the organizational field is structured.

Originality/value

– The paper contributes to the accounting literature by investigating how institutional work and operating under contradictory logics explain management accounting change.
Resource organization and firm performance
Authors: Andersén Jim , Samuelsson Joachim
Published: June 2016

Purpose

– The purpose of this paper is to examine how entrepreneurial orientation (EO) and the use of management accounting practices (MAPs) in decision making affects the profitability of small- and medium-sized enterprises (SMEs), and also to analyze the extent to which EO and the use of MAPs affects profitability differently in growing and non-growing SMEs.

Design/methodology/approach

– The paper employs an empirical investigation which is based on a sample of 153 Swedish manufacturing SMEs. The data are analyzed by two- and three-way interaction regressions.

Findings

– EO and MAPs have a positive effect on profitability in non-growing SMEs, but the combined effect of EO and MAPs has no additional effect. However, for growing SMEs, high usage of MAPs in decision making is a prerequisite for EO to influence profitability.

Originality/value

– This study is the first to use the resource-based view to examine the relationship between two dimensions of resource organization and SME profitability. EO is used as a proxy for how resources are organized in order to identify opportunities, and MAPs are used as a proxy for how efficiently resources are organized.
An investigation into the role of emotion in leadership development for entrepreneurs
Authors: Huxtable-Thomas Louisa A. , Hannon Paul D , Thomas Steffan W.
Published: June 2016

Purpose

– The Holy Grail of leadership learning is to stimulate behavioural changes that continue beyond the learning environment into the workplace, ultimately leading to improved productivity and value. The purpose of this paper is to explore the interface between emotion and leadership learning and provides evidence from research undertaken in Wales (UK) to support further research on the use of emotion in this endeavour.

Design/methodology/approach

– Unique access to a successful programme of guided leadership development for owner-managers of small and medium sized enterprises (SMEs) in Wales, UK, provided an opportunity to observe emotion being used and experienced by both learners and trainers. Literature reviews were used to inform initial inferences made during participant observations of a sample of the learners (n=91). Focus groups were undertaken with a sample (n=27) of participants in order to determine the emotional impact and perceived effectiveness of the method by the learners.

Findings

– The data corroborated the authors’ observations that emotion plays a role in the leadership practice of the learners and in the learning process. No appropriate conceptual model exists that describes this learning method or its mode of impact upon learning. A gap exists in the academic understanding of this observed social reality and multi-disciplinary research is required in order to further characterise and understand it.

Practical implications

– Improvements in leadership have been consistently linked to improvements in firm performance. Bringing new insights that lead to effective learning and constructive behaviour changes in the leaders of SMEs and their employees could have profound positive impacts on entrepreneurial economies.

Originality/value

– This novel perspective on leadership development within the life world of the entrepreneur moves away from the established literature which has traditionally focused on cognitive or conative constructs, often focused on the corporate or large organisation leader, and calls for further research into the synthesis of leadership, entrepreneurship and emotion.
Learning approaches, demographic factors to predict academic outcomes
Authors: Nguyen Tuan Minh
Published: June 2016

Purpose

– The purpose of this paper is to predict academic outcome in math and math-related subjects using learning approaches and demographic factors.

Design/methodology/approach

– ASSIST was used as the instrumentation to measure learning approaches. The study was conducted in the International University of Vietnam with 616 participants. An exploratory factor analysis, reliability, and correlation tests were performed before multiple regression analyses were carried out using SPSS 20.0. t-Tests to further discover relationships between learning approaches and demographic factors were also conducted.

Findings

– Females are more inclined to strategic approach, but not deep or surface by comparison with males. There is no relationship between parental education and learning approaches. Students with math preference in high school have tendency to use deep and strategic approach, but stay away from surface in higher education. Surface approach and admission mark have relationships with academic outcome; but gender, parental education, and math preference in high school do not have.

Research limitations/implications

– This model can explain only 15.5 percent of the variation of academic outcome. In addition, it may not be applicable to predict academic outcomes of subjects which are not math related.

Originality/value

– Surface approach has negative impact on academic outcome in math or math-related subjects, but the opposite is true for admission mark. Additionally, deep and strategic approach have no relationship with academic outcome.
Knowledge valorisation
Authors: Hladchenko Myroslava
Published: June 2016

Purpose

– The purpose of this paper is to explore the reasons of the success of the Netherlands in knowledge valorisation: what are the actors that participate in knowledge valorisation process and what are their functions; what is the route of knowledge in valorisation; what “surplus value” does knowledge gain in the valorisation process.

Design/methodology/approach

– Documentary and content analysis of the documents that regulate the knowledge valorisation on the level of the national policy and on the level of universities.

Findings

– The success of the Netherlands in the knowledge valorisation can be explained by the creation of the process in which its main actors – state and universities collaborate and clearly understand and perform their functions and involve into the collaboration, the representatives of the industry. The state managed to create on the level of the country beneficial environment for knowledge valorisation that includes legal basis and establishment of organizations which provide funding for knowledge valorisation. Universities in their turn also have created beneficial and stimulating conditions for knowledge valorisation – science parks and valorisation centres provide support to the academics in the knowledge valorisation process. The process of valorisation at the university is built on cooperative relationship between researchers and management of the universities. Cooperation between researchers and management structures of the university which consult and support them in the process of valorisation is beneficial for both sides. Surplus value in the knowledge valorisation process can be financial and societal, but in some way they coincide because valorisation accelerates scientific progress, supports the economic development of the region and the Netherlands.

Research limitations/implications

– In research were explored documents that regulate knowledge valorisation on the level of state and on the level of university (strategic plans of the Dutch universities). This paper provides a basis for the substantial development of the general framework for the development of the policy at the area of knowledge valorisation and initiatives by higher education institutions.

Practical implications

– The experience of the Netherlands in policymaking in area of knowledge valorisation and initiatives of the Dutch universities can be used as the basis for the development and implementation of the national policies of knowledge valorisation.

Social implications

– The experience of the development of the valorisation initiatives of the Dutch universities can be used as the basis for the development and implementation of the valorisation initiatives of the higher education institutions.

Originality/value

– The study takes a documentary analysis to understand and explain the essence of the term “valorisation”, its types – societal and financial, the input of the main actors into knowledge valorisation process and to determine what surplus value and benefits are created during this process.
State actors’ mobilisation of resources for innovation: a case study of a Chinese vaccine
Authors: Shih Tommy , Linné Åse
Published: June 2016

Purpose

– The purpose of this paper is to explore how state actors mobilise resources in business networks to facilitate innovation.

Design/methodology/approach

– A single case study method is used. The case from the Chinese biotechnology sector illustrates how state actors mobilise resources in a network context in order to develop, produce and use a vaccine.

Findings

– The case findings demonstrate that state actors indirectly, as well as actively, are involved in the whole innovation process by mobilising resources necessary for the development, production and use of the vaccine. State actors influence other actors, both political and business, and provide resources in order to facilitate innovation.

Practical implications

– The paper illustrates that state actors, in the specific case, play an important and active role throughout the whole innovation process. This opens up the issue of the possible extended role of state actors in innovation.

Originality/value

– Over the past decades, Chinese state actors have played an active role in the business landscape. This paper explores state actors’ influence on the innovation process on the network level.
A Black Swan in the district? An IMP perspective on immigrant entrepreneurship and changes in industrial districts
Authors: Milanesi Matilde , Guercini Simone , Waluszewski Alexandra
Published: June 2016

Purpose

– The purpose of this paper is to discuss the changes of the Italian textile district of Prato, considered an exemplary case of the industrial district (ID) model, using a business network perspective. The “Black Swan” metaphor is used to address the changes in the Prato textile district in order to understand whether such changes have been an unexpected and unpredictable phenomenon, or they can be explain with a different theoretical tool-box, namely, that developed by the industrial network approach.

Design/methodology/approach

– The paper utilizes already published studies on the changes of the textile/fashion companies located to the Prato area. Both studies that have been carried out within an ID approach and those carried out with an Industrial Marketing and Purchasing (IMP) point of departure are considered in the research. Both types of studies were utilized to identify empirical observed changes of the producer, respectively user setting that the Prato located companies was related to, including identification of changes affecting both the local setting and the larger network it was related to.

Findings

– The utilization of the IMP model proposes a learning ground that exceed the local context and open ups of investigations of opportunities and threats stemming from interactions across spatial borders. Analysed from an interactive point of view, in the specific context of Prato, the exploitation of the opportunities given by establishing relationship between natives and migrants actors goes through the creation of interactions among actors representing specific resource combinations and activity structures – within and outside the local community.

Originality/value

– The paper concerns how the same research object – the changes of the Prato district – appears from another perspective different from the ID theory, namely, the industrial network approach developed by scholars of the IMP Group.
Harnessing network-based intellectual capital in online academic networks. From the organizational policies and practices towards competitiveness
Authors: Vătămănescu Elena-Mădălina , Andrei Andreia Gabriela , Dumitriu Diana-Luiza , Leovaridis Cristina
Published: June 2016

Purpose

The paper aims to investigate the standpoints and practices of university members from European developing countries regarding the harnessing of the intellectual capital (IC) within online academic social networks.

Design/methodology/approach

A questionnaire-based survey with 210 university members was conducted, with the indicators adopting prior measurement scales which were further adapted to a network framework.

Findings

The organizational policies and practices relate positively and highly significantly with the valuation of the network-based IC components. Moreover, 63 per cent of the professional and organizational competitiveness of higher education institutions is determined by the exploitation of the IC embedded in online academic networks.

Research limitations/implications

All survey respondents were from the European developing countries, which may limit the general applicability of the findings. Also, the emphasis is laid solely on online academic networks.

Practical implications

This paper brings to the fore both the potential and the state-of-the-art in leveraging the IC of online specialized networks which are indicative of the academic field. When acknowledged as such, the network-based IC is liable to generate substantial competitive advantages at the professional and organizational levels at the same time.

Originality/value

This research adds to the extant literature in two main ways. First, it advances a new construct – network-based IC – in the context of the online academic social networks. Second, it proposes a research model for addressing the network-based IC from a competitive advantage perspective.