bluuebunny/crossref_metadata_2025 huggingface dataset:
New Games, New Rules: Big Data and the Changing Context of Strategy
Authors: Constantiou Ioanna D , Kallinikos Jannis
Published: September 2014

Big data and the mechanisms by which it is produced and disseminated introduce important changes in the ways information is generated and made relevant for organizations. Big data often represents miscellaneous records of the whereabouts of large and shifting online crowds. It is frequently agnostic, in the sense of being produced for generic purposes or purposes different from those sought by big data crunching. It is based on varying formats and modes of communication (e.g., texts, image and sound), raising severe problems of semiotic translation and meaning compatibility. Crucially, the usefulness of big data rests on their steady updatability, a condition that reduces the time span within which this data is useful or relevant. Jointly, these attributes challenge established rules of strategy making as these are manifested in the canons of procuring structured information of lasting value that addresses specific and long-term organizational objectives. The developments underlying big data thus seem to carry important implications for strategy making, and the data and information practices with which strategy has been associated. We conclude by placing the understanding of these changes within the wider social and institutional context of longstanding data practices and the significance they carry for management and organizations.
Microjet formation and hard x-ray production from a liquid metal target irradiated by intense femtosecond laser pulses
Authors: Lar'kin A. , Uryupina D. , Ivanov K. , Savel'ev A. , Bonnet T. , Gobet F. , Hannachi F. , Tarisien M. , Versteegen M. , Spohr K. , Breil J. , Chimier B. , Dorchies F. , Fourment C. , Leguay P.-M. , Tikhonchuk V. T.
Published: September 2014

By using a liquid metal as a target one may significantly enhance the yield of hard x-rays with a sequence of two intense femtosecond laser pulses. The influence of the time delay between the two pulses is studied experimentally and interpreted with numerical simulations. It was suggested that the first arbitrary weak pulse produces microjets from the target surface, while the second intense pulse provides an efficient electron heating and acceleration along the jet surface. These energetic electrons are the source of x-ray emission while striking the target surface. The microjet formation is explained based on the results given by both optical diagnostics and hydrodynamic modeling by a collision of shocks originated from two distinct zones of laser energy deposition.
Plasmons in molecules: Microscopic characterization based on orbital transitions and momentum conservation
Authors: Krauter Caroline M. , Schirmer Jochen , Jacob Christoph R. , Pernpointner Markus , Dreuw Andreas
Published: September 2014

In solid state physics, electronic excitations are often classified as plasmons or single-particle excitations. The former class of states refers to collective oscillations of the electron density. The random-phase approximation allows for a quantum-theoretical treatment and a characterization on a microscopic level as a coherent superposition of a large number of particle-hole transitions with the same momentum transfer. However, small systems such as molecules or small nanoclusters lack the basic properties (momentum conservation and uniform exchange interaction) responsible for the formation of plasmons in the solid-state case. Despite an enhanced interest in plasmon-based technologies and an increasing number of studies regarding plasmons in molecules and small nanoclusters, their definition on a microscopic level of theory remains ambiguous. In this work, we analyze the microscopic properties of molecular plasmons in comparison with the homogeneous electron gas as a model system. Subsequently, the applicability of the derived characteristics is validated by analyzing the electronic excitation vectors with respect to orbital transitions for two linear polyenes within second order versions of the algebraic diagrammatic construction scheme for the polarization propagator.
Investigation of sensitizer ions tunable-distribution in fluoride nanoparticles for efficient accretive three-center energy transfer
Authors: Guo Hui , Yu Hua , Lao Aiqing , Chang Lifen , Gao Shaohua , Zhang Haoxiong , Zhou Taojie , Zhao Lijuan
Published: September 2014

Cooperative upconversion luminescence of Yb3+-Yb3+ couples and three-center energy transfer mechanisms have been deeply investigated in Yb3+ doped and Yb3+-Tb3+ co-doped β-PbF2 nanoparticles. As sensitizer ions, the distribution of Yb3+ ions, which is a key factor that affects the cooperative upconversion luminescence and three-center energy transfer processes, can be tuned by the structure of nanoparticles. Based on the three-center distributions in tetragonal PbYbxTb1−xF5 nanoparticles, two different energy transfer models, Cooperative Energy Transfer (CET) and Accretive Energy Transfer (AET) mechanisms were established. Especially, AET model is observed and verified in this work for the first time. Experimental results obtained from photoluminescence spectroscopy study are in agreement with the theoretical calculations by applying rate equations in these models, strongly supporting the proposed three-center energy transfer mechanisms. The sensitization between Yb3+ ions only existing in AET process can greatly improve the energy transfer rates, further to enhance the quantum efficiency. The results that the calculated luminescence quantum efficiency in AET quantum cutting process is much higher than that in CET process (134% and 104%, respectively), can benefit for further increasing the conversion efficiency of c-Si solar cells.
Laboratory-size three-dimensional x-ray microscope with Wolter type I mirror optics and an electron-impact water window x-ray source
Authors: Ohsuka Shinji , Ohba Akira , Onoda Shinobu , Nakamoto Katsuhiro , Nakano Tomoyasu , Miyoshi Motosuke , Soda Keita , Hamakubo Takao
Published: September 2014

We constructed a laboratory-size three-dimensional water window x-ray microscope that combines wide-field transmission x-ray microscopy with tomographic reconstruction techniques, and observed bio-medical samples to evaluate its applicability to life science research fields. It consists of a condenser and an objective grazing incidence Wolter type I mirror, an electron-impact type oxygen Kα x-ray source, and a back-illuminated CCD for x-ray imaging. A spatial resolution limit of around 1.0 line pairs per micrometer was obtained for two-dimensional transmission images, and 1-μm scale three-dimensional fine structures were resolved.
A systematic approach to vertically excited states of ethylene using configuration interaction and coupled cluster techniques
Authors: Feller David , Peterson Kirk A. , Davidson Ernest R.
Published: September 2014

A systematic sequence of configuration interaction and coupled cluster calculations were used to describe selected low-lying singlet and triplet vertically excited states of ethylene with the goal of approaching the all electron, full configuration interaction/complete basis set limit. Included among these is the notoriously difficult, mixed valence/Rydberg 1B1u V state. Techniques included complete active space and iterative natural orbital configuration interaction with large reference spaces which led to variational spaces of 1.8 × 109 parameters. Care was taken to avoid unintentionally biasing the results due to the widely recognized sensitivity of the V state to the details of the calculation. The lowest vertical and adiabatic ionization potentials to the 2B3u and 2B3 states were also determined. In addition, the heat of formation of twisted ethylene 3A1 was obtained from large basis set coupled cluster theory calculations including corrections for core/valence, scalar relativistic and higher order correlation recovery.
Theoretical spectroscopic characterization at low temperatures of S-methyl thioformate and O-methyl thioformate
Authors: Senent M. L. , Puzzarini C. , Hochlaf M. , Domínguez-Gómez R. , Carvajal M.
Published: September 2014

Highly correlated ab initio methods are employed to determine spectroscopic properties at low temperatures of two S-analogs of methyl formate: S-methyl thioformate CH3-S-CHO (MSCHO) and O-methyl thioformate CH3-O-CHS (MOCHS). Both species are detectable and they are expected to play an important role in Astrochemistry. Molecular properties are compared with those of the O-analog, methyl formate. Both isomers present two conformers cis and trans. cis-CH3-S-CHO represents the most stable structure lying 4372.2 cm−1 below cis-CH3-O-CHS. The energy difference between the cis and trans forms is drastically lower for MSCHO (1134 cm−1) than for MOCHS (1963.6 cm−1). Harmonic and anharmonic fundamentals and the corresponding intensities, as well as the rotational constants for the ground vibrational and first excited torsional states and the centrifugal distortions constants, are provided. Low torsional energy levels have been obtained by solving variationally a two dimensional Hamiltonian expressed in terms of the two torsional degrees of freedom. The corresponding 2D potential energy surfaces have been computed at the CCSD(T)/aug-cc-pVTZ level of theory. The methyl torsional barriers V3(cis) are determined to be 139.7 cm−1 (CH3-S-CHO) and 670.4 cm−1 (CH3-O-CHS). The A/E splitting of ground torsional state has been estimated to be 0.438 cm−1 for CH3-S-CHO and negligible for CH3-O-CHS.
Generation and structural characterization of aluminum cyanoacetylide
Authors: Cabezas Carlos , Barrientos Carmen , Largo Antonio , Guillemin Jean-Claude , Cernicharo José , Peña Isabel , Alonso José L.
Published: September 2014

Combined spectroscopy measurements and theoretical calculations bring to light a first investigation of a metallic cyanoacetylide, AlC3N, using laser ablation molecular beam Fourier transform microwave spectroscopy. This molecule was synthesized in a supersonic expansion by the reaction of aluminum vapour with C3N, produced from solid aluminum rods and BrCCCN in a newly constructed ablation-heating nozzle device. A set of accurate rotational and 27Al and 14N nuclear quadrupole coupling constants have been determined from the analysis of the rotational spectrum and compared with those predicted in a high-level ab initio study, conducting to the assignment of the observed species to linear AlCCCN. We have searched for this species towards the carbon-rich evolved star IRC + 10216 but only an upper limit to its abundance has been obtained.
Molecular simulation study of role of polymer–particle interactions in the strain-dependent viscoelasticity of elastomers (Payne effect)
Authors: Chen Yulong , Li Ziwei , Wen Shipeng , Yang Qingyuan , Zhang Liqun , Zhong Chongli , Liu Li
Published: September 2014

The strain-amplitude dependence of viscoelastic behavior of model crosslinked elastomers containing various concentrations of spherical nanoparticles (NPs) was studied by non-equilibrium molecular dynamics simulation. All the filler NPs were in monodispersed state and the interactions between these particles were purely repulsive. The polymer–particle interactions were attractive and their interaction energies were tuned in a broad range. Through the computational study, many important features of the behavior of particle-reinforced elastomers observed in experiments, including the Payne effect, were successfully reproduced. It was shown that the magnitude of the Payne effect was found to depend on the polymer–particle interaction and the filler loading. By examining the microstructures of the simulation systems and their evolution during oscillatory shear, four different mechanisms for the role of the polymer–particle interactions in the Payne effect were revealed that consist of the debonding of polymer chains from NP surfaces, the breakage of polymer-shell-bridged NP network, the rearrangement of the NPs in the network into different layers and the shear-induced yielding of the rigid polymer shell in-between neighboring NPs.
Simple Harish-Chandra modules over super Schrödinger algebra in (1+1) dimensional spacetime
Authors: Zhang Xiufu , Cai Yan-an , Wang Yongjie
Published: September 2014

The N = 1 super Schrödinger algebra \documentclass[12pt]{minimal}\begin{document}$\mathcal {S}(1|1)$\end{document}S(1|1) in (1+1) dimensional spacetime contains a subalgebra isomorphic to \documentclass[12pt]{minimal}\begin{document}$\mathfrak {osp}(1|2)$\end{document}osp(1|2)-module. Let V be a simple weight module for the N = 1 super Schrödinger algebra \documentclass[12pt]{minimal}\begin{document}$\mathcal {S}(1|1)$\end{document}S(1|1) but not a simple \documentclass[12pt]{minimal}\begin{document}$\mathfrak {osp}(1|2)$\end{document}osp(1|2)-module. Let ω ∈ supp(V). If V is neither a highest weight module nor a lowest weight module for \documentclass[12pt]{minimal}\begin{document}$\mathcal {S}(1|1)$\end{document}S(1|1), we prove that \documentclass[12pt]{minimal}\begin{document}$\mathrm{supp}(V)=\omega +\mathbb {Z}$\end{document} supp (V)=ω+Z, and all non-trivial weight spaces of V have the same dimension. We prove that if V is a Harish-Chandra module, then it is a highest weight module, or lowest weight module, or a twisted localization of a highest weight module.
Effect of external flow velocity on momentum transfer of dielectric barrier discharge plasma actuators
Authors: Pereira Ricardo , Ragni Daniele , Kotsonis Marios
Published: September 2014

An experimental study is performed towards identifying cross-talk effects between DBD plasma actuators and external flow. An actuator is positioned in a boundary layer operated in a range of free stream velocities from 0 to 60 m/s, and tested both in counter-flow and co-flow forcing configurations. Electrical measurements are used for estimating the power consumption and the discharge formation is visualized using a CCD camera. The actuator's force is measured using a sensitive load cell. Results show the power consumption is constant for different flow velocities and actuator configurations. The plasma light emission is constant for co-flow forcing but shows a trend of increasing intensity with counter-flow forcing for increasing free stream velocities. The measured force is constant for free stream velocities larger than 20 m/s, with same magnitude and opposite direction for the counter-flow and co-flow configurations. In quiescent conditions, the measured force is smaller due to the change in wall shear force by the induced wall-jet. An analytical model is presented to estimate the influence of external flow on the actuator force. It is based on conservation of momentum through the ion-neutral collisional process while including the contribution of the wall shear force. Satisfactory agreement is found between the prediction of the model and experimental data at different external flow velocities.
Neutral particle effects on the spin-dependent electron scattering in dense plasmas
Authors: Lee Gyeong Won , Jung Young-Dae
Published: September 2014

The influence of neutral particle collisions on the spin-channel preference for spin-asymmetry scattering is investigated in dense plasmas. The effective electron-electron interaction potential taking into account the electron-neutral collision effects is employed to obtain the scattering cross sections for the spin-triplet and singlet states and spin-asymmetry scattering parameter. It is found that the electron-neutral collision effect enhances the spin-asymmetry scattering parameter as well as the preference for the spin-singlet scattering channel. It is also shown that the preference for the spin-singlet scattering channel increases with an increase of the thermal energy. In addition, it is found that the angular averaged spin-asymmetry parameter decreases with increasing collision frequency and thermal energy. The variations of the spin-singlet and spin-triplet scattering channels are also discussed.
Giant planar Hall effect in reactive sputtered epitaxial CrxFe3–xO4 films
Authors: Li P. , Cui W. Y. , Jin C. , Bai H. L.
Published: September 2014

The epitaxial CrxFe3-xO4 films were fabricated by dc reactive sputtering on MgO (001) substrates. The longitudinal resistivity ρxx was enhanced 3 orders of magnitude with the increase of Cr content x from 0 to 0.87. The tunneling magnetoresistance like planar Hall effect in the CrxFe3-xO4 films was observed while the angle between ⟨100⟩ in (001) oriented films and the direction of magnetic field is 45° and 135°, respectively. Both the phase relation of angular dependent planar Hall resistivity ρxy and the numeral relation of ρxy with longitudinal resistivity difference ρ//−ρ⊥ cannot be understood by the planar Hall effect expression in isotropic magnetic medium. The largest planar Hall resistivity was ∼105 μΩ cm for x = 0.71, which is one, two, and six orders of magnitude larger than that in Fe3O4, GaMnAs, and ferromagnetic metals, respectively. The giant planar Hall resistivity ρxy is weak saturated at high fields and increases with the magnetic field. This giant planar Hall effect in the highly resistive CrxFe3-xO4 films is closely correlated to the longitudinal resistivity and antiphase boundaries.
A signature for turbulence driven magnetic islands
Authors: Agullo O. , Muraglia M. , Poyé A. , Benkadda S. , Yagi M. , Garbet X. , Sen A.
Published: September 2014

We investigate the properties of magnetic islands arising from tearing instabilities that are driven by an interchange turbulence. We find that such islands possess a specific signature that permits an identification of their origin. We demonstrate that the persistence of a small scale turbulence maintains a mean pressure profile, whose characteristics makes it possible to discriminate between turbulence driven islands from those arising due to an unfavourable plasma current density gradient. We also find that the island poloidal turnover time, in the steady state, is independent of the levels of the interchange and tearing energy sources. Finally, we show that a mixing length approach is adequate to make theoretical predictions concerning island flattening in the island rotation frame.
Dual-mode on-demand droplet routing in multiple microchannels using a magnetic fluid as carrier phase
Authors: Kim Jitae , Won June , Song Simon
Published: September 2014

We present dual-mode, on-demand droplet routing in a multiple-outlet microfluidic device using an oil-based magnetic fluid. Magnetite (Fe3O4) nanoparticle-contained oleic acid (MNOA) was used as a carrier phase for droplet generation and manipulation. The water-in-MNOA droplets were selectively distributed in a curved microchannel with three branches by utilizing both a hydrodynamic laminar flow pattern and an external magnetic field. Without the applied magnetic field, the droplets travelled along a hydrodynamic centerline that was displaced at each bifurcating junction. However, in the presence of a permanent magnet, they were repelled from the centerline and diverted into the desired channel when the repelled distance exceeded the minimum offset allocated to the channel. The repelled distance, which is proportional to the magnetic field gradient, was manipulated by controlling the magnet's distance from the device. To evaluate routing performance, three different sizes of droplets with diameters of 63, 88, and 102 μm were directed into designated outlets with the magnet positioned at varying distances. The result demonstrated that the 102-μm droplets were sorted with an accuracy of ∼93%. Our technique enables on-demand droplet routing in multiple outlet channels by simply manipulating magnet positions (active mode) as well as size-based droplet separation with a fixed magnet position (passive mode).
Masked-backlighter technique used to simultaneously image x-ray absorption and x-ray emission from an inertial confinement fusion plasma
Authors: Marshall F. J. , Radha P. B.
Published: September 2014

A method to simultaneously image both the absorption and the self-emission of an imploding inertial confinement fusion plasma has been demonstrated on the OMEGA Laser System. The technique involves the use of a high-Z backlighter, half of which is covered with a low-Z material, and a high-speed x-ray framing camera aligned to capture images backlit by this masked backlighter. Two strips of the four-strip framing camera record images backlit by the high-Z portion of the backlighter, while the other two strips record images aligned with the low-Z portion of the backlighter. The emission from the low-Z material is effectively eliminated by a high-Z filter positioned in front of the framing camera, limiting the detected backlighter emission to that of the principal emission line of the high-Z material. As a result, half of the images are of self-emission from the plasma and the other half are of self-emission plus the backlighter. The advantage of this technique is that the self-emission simultaneous with backlighter absorption is independently measured from a nearby direction. The absorption occurs only in the high-Z backlit frames and is either spatially separated from the emission or the self-emission is suppressed by filtering, or by using a backlighter much brighter than the self-emission, or by subtraction. The masked-backlighter technique has been used on the OMEGA Laser System to simultaneously measure the emission profiles and the absorption profiles of polar-driven implosions.
Impact of strain on electronic defects in (Mg,Zn)O thin films
Authors: Schmidt Florian , Müller Stefan , von Wenckstern Holger , Benndorf Gabriele , Pickenhain Rainer , Grundmann Marius
Published: September 2014

We have investigated the impact of strain on the incorporation and the properties of extended and point defects in (Mg,Zn)O thin films by means of photoluminescence, X-ray diffraction, deep-level transient spectroscopy (DLTS), and deep-level optical spectroscopy. The recombination line Y2, previously detected in ZnO thin films grown on an Al-doped ZnO buffer layer and attributed to tensile strain, was exclusively found in (Mg,Zn)O samples being under tensile strain and is absent in relaxed or compressively strained thin films. Furthermore a structural defect E3′ can be detected via DLTS measurements and is only incorporated in tensile strained samples. Finally it is shown that the omnipresent deep-level E3 in ZnO can only be optically recharged in relaxed ZnO samples.
Wall heat transfer effects on the hydro/thermal behaviour of Poiseuille flow in micro/nanochannels
Authors: Akhlaghi Hassan , Roohi Ehsan , Balaj Mojtaba , Dadzie S. Kokou
Published: September 2014

We investigate effects of wall heat transfer on the structure of pressure driven flow in micro/nanochannels using the Direct Simulation Monte Carlo method. The effects of non-zero wall heat flux on the pressure distribution, velocity profiles, heat flow patterns, and the mass flow rate are reported. The simulation results show that cooling decreases slip at the wall and pressure along the channel. Cooling changes the heat flow direction along the channel while heating does not. At higher degree of rarefaction, the direction of the heat flow is mainly axial along the channel. An existence of cold-to-hot heat transfer process is demonstrated in the cooling wall case. Cooling can also create a heat singularity point in the domain. There is a critical Knudsen number about unity for which heating or cooling does not affect the mass flow rate through the channel. Below the critical Knudsen number, heating decreases and cooling increases the mass flow rate. Above it, heating increases and cooling decreases the mass flow rate.
The effect of electron-electron interaction induced dephasing on electronic transport in graphene nanoribbons
Authors: Kahnoj Sina Soleimani , Touski Shoeib Babaee , Pourfath Mahdi
Published: September 2014

The effect of dephasing induced by electron-electron interaction on electronic transport in graphene nanoribbons is theoretically investigated. In the presence of disorder in graphene nanoribbons, wavefunction of electrons can set up standing waves along the channel and the conductance exponentially decreases with the ribbon's length. Employing the non-equilibrium Green's function formalism along with an accurate model for describing the dephasing induced by electron-electron interaction, we show that this kind of interaction prevents localization and transport of electrons remains in the diffusive regime where the conductance is inversely proportional to the ribbon's length.
Band alignment study of lattice-matched In0.49Ga0.51P and Ge using x-ray photoelectron spectroscopy
Authors: Owen Man Hon Samuel , Zhou Qian , Gong Xiao , Zhang Zheng , Pan Ji Sheng , Loke Wan Khai , Wicaksono Satrio , Yoon Soon Fatt , Tok Eng Soon , Yeo Yee-Chia
Published: September 2014

Lattice-matched In0.49Ga0.51P was grown on a p-type Ge(100) substrate with a 10° off-cut towards the (111) by low temperature molecular beam epitaxy, and the band-alignment of In0.49Ga0.51P on Ge substrate was obtained by high resolution x-ray photoelectron spectroscopy. The valence band offset for the InGaP/Ge(100) interface was found to be 0.64 ± 0.12 eV, with a corresponding conduction band offset of 0.60 ± 0.12 eV. The InGaP/Ge interface is found to be of the type I band alignment.
A unified physical model of Seebeck coefficient in amorphous oxide semiconductor thin-film transistors
Authors: Lu Nianduan , Li Ling , Sun Pengxiao , Banerjee Writam , Liu Ming
Published: September 2014

A unified physical model for Seebeck coefficient was presented based on the multiple-trapping and release theory for amorphous oxide semiconductor thin-film transistors. According to the proposed model, the Seebeck coefficient is attributed to the Fermi-Dirac statistics combined with the energy dependent trap density of states and the gate-voltage dependence of the quasi-Fermi level. The simulation results show that the gate voltage, energy disorder, and temperature dependent Seebeck coefficient can be well described. The calculation also shows a good agreement with the experimental data in amorphous In-Ga-Zn-O thin-film transistor.
Roles of superthermal electrons and positrons on positron-acoustic solitary waves and double layers in electron–positron–ion plasmas
Authors: Alam M. S. , Uddin M. J. , Masud M. M. , Mamun A. A.
Published: September 2014

Positron-acoustic (PA) solitary waves (SWs) and double layers (DLs) in four-component plasmas consisting of immobile positive ions, mobile cold positrons, and superthermal (kappa distributed) hot positrons and electrons are investigated both numerically and analytically by deriving Korteweg–de Vries (K-dV), modified K-dV (mK-dV), and Gardner equations along with their DLs solutions using the reductive perturbation method. It is examined that depending on the plasma parameters, the K-dV SWs, Gardner SWs, and DLs support either compressive or rarefactive structures, whereas mK-dV SWs support only compressive structure. It is also found that the presence of superthermal (kappa distributed) hot positrons and hot electrons significantly modify the basic features of PA SWs as well as PA DLs. Besides, the critical number density ratio of hot positrons and cold positrons play an important role in the polarity of PA SWs and DLs. The implications of our results in different space as well as laboratory plasma environments are briefly discussed.
Improved magnetoelectric performance of the Ni-P/Ni/Pb(Zr,TiO)3 cylindrical layered composites
Authors: Pan D. A. , Wang J. , Zuo Z. J. , Zhang S. G. , Liu B. , Volinsky A. A. , Qiao L. J.
Published: September 2014

The Ni-P/Ni/Pb(Zr,TiO)3 (PZT) cylindrical layered magnetoelectric (ME) composites have been prepared by electroless deposition and electrodeposition. The ME effect in the axial mode was researched in this paper. Compared with that of the Ni/PZT and Ni-P/PZT composites, the Ni-P/Ni/PZT composites have both lower optimal magnetic field and higher ME voltage coefficient. The reason for the ME improvement can be ascribed to the flux concentration effect and the compressive stress in the Ni layers induced by the high permeability Ni-P layers. These results open up a suitable way to enhance the sensitivity and optimize the design of ME devices for practical application.
Touch sensors based on planar liquid crystal-gated-organic field-effect transistors
Authors: Seo Jooyeok , Lee Chulyeon , Han Hyemi , Lee Sooyong , Nam Sungho , Kim Hwajeong , Lee Joon-Hyung , Park Soo-Young , Kang Inn-Kyu , Kim Youngkyoo
Published: September 2014

We report a tactile touch sensor based on a planar liquid crystal-gated-organic field-effect transistor (LC-g-OFET) structure. The LC-g-OFET touch sensors were fabricated by forming the 10 μm thick LC layer (4-cyano-4′-pentylbiphenyl - 5CB) on top of the 50 nm thick channel layer (poly(3-hexylthiophene) - P3HT) that is coated on the in-plane aligned drain/source/gate electrodes (indium-tin oxide - ITO). As an external physical stimulation to examine the tactile touch performance, a weak nitrogen flow (83.3 μl/s) was employed to stimulate the LC layer of the touch device. The LC-g-OFET device exhibited p-type transistor characteristics with a hole mobility of 1.5 cm2/Vs, but no sensing current by the nitrogen flow touch was measured at sufficiently high drain (VD) and gate (VG) voltages. However, a clear sensing current signal was detected at lower voltages, which was quite sensitive to the combination of VD and VG. The best voltage combination was VD = −0.2 V and VG = −1 V for the highest ratio of signal currents to base currents (i.e., signal-to-noise ratio). The change in the LC alignment upon the nitrogen flow touch was assigned as the mechanism for the present LC-g-OFET touch sensors.
Direct measurement of the dielectrophoresis forces acting on micro-objects using optical tweezers and a simple microfluidic chip
Authors: Park In Soo , Park Se Hee , Yoon Dae Sung , Lee Sang Woo , Kim Beop-Min
Published: September 2014

We constructed a reliable frequency-dependent dielectrophoretic (DEP) force measurement system based on optical tweezers and a microfluidic chip. Using this system, we directly measured the frequency-dependent DEP forces acting on polystyrene beads while varying various parameters, which were all verified by theoretical simulations. We also investigated the DEP characteristics of non-functionalized and carboxyl-functionalized polystyrene beads in solutions with different conductivities by associating the measured crossover frequencies with a theoretical DEP model. This system can be used as a quantifying tool for surface conductance assays by characterizing the DEP forces acting on micro-objects in various experimental conditions.
Large piezoresistive effect in surface conductive nanocrystalline diamond
Authors: Janssens S. D. , Drijkoningen S. , Haenen K.
Published: September 2014

Surface conductivity in hydrogen-terminated single crystal diamond is an intriguing phenomenon for fundamental reasons as well as for application driven research. Surface conductivity is also observed in hydrogen-terminated nanocrystalline diamond although the electronic transport mechanisms remain unclear. In this work, the piezoresistive properties of intrinsic surface conductive nanocrystalline diamond are investigated. A gauge factor of 35 is calculated from bulging a diamond membrane of 350 nm thick, with a diameter of 656 μm and a sheet resistance of 1.45 MΩ/sq. The large piezoresistive effect is reasoned to originate directly from strain-induced changes in the resistivity of the grain boundaries. Additionally, we ascribe a small time-dependent fraction of the piezoresistive effect to charge trapping of charge carriers at grain boundaries. In conclusion, time-dependent piezoresistive effect measurements act as a tool for deeper understanding the complex electronic transport mechanisms induced by grain boundaries in a polycrystalline material or nanocomposite.
Down-regulation of adipogenesis of mesenchymal stem cells by oscillating high-gradient magnetic fields and mechanical vibration
Authors: Zablotskii V. , Lunov O. , Novotná B. , Churpita O. , Trošan P. , Holáň V. , Syková E. , Dejneka A. , Kubinová Š.
Published: September 2014

Nowadays, the focus in medicine on molecular genetics has resulted in a disregard for the physical basis of treatment even though many diseases originate from changes in cellular mechanics. Perturbations of the cellular nanomechanics promote pathologies, including cardiovascular disease and cancer. Furthermore, whilst the biological and therapeutic effects of magnetic fields are a well-established fact, to date the underlying mechanisms remain obscure. Here, we show that oscillating high-gradient magnetic field (HGMF) and mechanical vibration affect adipogenic differentiation of mesenchymal stem cells by the transmission of mechanical stress to the cell cytoskeleton, resulting in F-actin remodelling and subsequent down-regulation of adipogenic genes adiponectin, PPARγ, and AP2. Our findings propose an insight into the regulation of cellular nanomechanics, and provide a basis for better controlled down-regulation of stem cell adipogenesis by HGMF, which may facilitate the development of challenging therapeutic strategies suitable for the remote control of biological systems.
Degenerate resistive switching and ultrahigh density storage in resistive memory
Authors: Lohn Andrew J. , Mickel Patrick R. , James Conrad D. , Marinella Matthew J.
Published: September 2014

We show that in tantalum oxide resistive memories, activation power provides a multi-level variable for information storage that can be set and read separately from the resistance. These two state variables (resistance and activation power) can be precisely controlled in two steps: (1) the possible activation power states are selected by partially reducing resistance, then (2) a subsequent partial increase in resistance specifies the resistance state and the final activation power state. We show that these states can be precisely written and read electrically, making this approach potentially amenable for ultra-high density memories. We provide a theoretical explanation for information storage and retrieval from activation power and experimentally demonstrate information storage in a third dimension related to the change in activation power with resistance.
Implementing a working together model for Aboriginal patients with acute coronary syndrome: an Aboriginal Hospital Liaison Officer and a specialist cardiac nurse working together to improve hospital care
Authors: Daws Karen , Punch Amanda , Winters Michelle , Posenelli Sonia , Willis John , MacIsaac Andrew , Rahman Muhammad Aziz , Worrall-Carter Linda
Published: September 2014

Acute coronary syndrome (ACS) contributes to the disparity in life expectancy between Aboriginal and non-Aboriginal Australians. Improving hospital care for Aboriginal patients has been identified as a means of addressing this disparity. This project developed and implemented a working together model of care, comprising an Aboriginal Hospital Liaison Officer and a specialist cardiac nurse, providing care coordination specifically directed at improving attendance at cardiac rehabilitation services for Aboriginal Australians in a large metropolitan hospital in Melbourne. A quality improvement framework using a retrospective case notes audit evaluated Aboriginal patients’ admissions to hospital and identified low attendance rates at cardiac rehabilitation services. A working together model of care coordination by an Aboriginal Hospital Liaison Officer and a specialist cardiac nurse was implemented to improve cardiac rehabilitation attendance in Aboriginal patients admitted with ACS to the cardiac wards of the hospital. A retrospective medical records audit showed that there were 68 Aboriginal patients admitted to the cardiac wards with ACS from 1 July 2008 to 30 June 2011. A referral to cardiac rehabilitation was recorded for 42% of these. During the implementation of the model of care, 13 of 15 patients (86%) received a referral to cardiac rehabilitation and eight of the 13 (62%) attended. Implementation of the working together model demonstrated improved referral to and attendance at cardiac rehabilitation services, thereby, has potential to prevent complications and mortality. What is known about the topic? Aboriginal Australians experience disparities in access to recommended care for acute coronary syndrome. This may contribute to the life expectancy gap between Aboriginal and non-Aboriginal Australians. What does this paper add? This paper describes a model of care involving an Aboriginal Hospital Liaisons Officer and a specialist cardiac nurse working together to improve hospital care and attendance at cardiac rehabilitation services for Aboriginal Australians with acute coronary syndrome. What are the implications for practitioners? The working together model of care could be implemented across mainstream health services where Aboriginal people attend for specialist care.
Resources and strategies for implementation of genomic selection in breeding of forage species
Authors: Forster J. W. , Hand M. L. , Cogan N. O. I. , Hayes B. J. , Spangenberg German C. , Smith K. F.
Published: September 2014

Forage species provide the major feed-base for livestock grazing industries supporting production of dairy products, red meat and animal fibres. Because of the complex, multifactorial and highly environmentally sensitive nature of many key breeders’ traits for forage crops, implementation of genomic selection (GS) is a particularly attractive option. Although basic strategies for GS implementation have been devised, forage species display a broad range of biological factors that may influence the precise design of GS-based programs. These factors are described and exemplified by reference to several temperate and warm-season grass and legume species. Current knowledge with respect to such factors, along with the availability of suitable genomic resources and prospects for future activities, is described for several representative species (white clover, tall fescue and phalaris). Generic issues and benefits associated with GS implementation in forage breeding are also assessed.
Australian school canteens: menu guideline adherence or avoidance?
Authors: Woods Julie , Bressan Alex , Langelaan Corrina , Mallon Angela , Palermo Claire
Published: September 2014

Issue addressed

Since 2005, all states and territories across Australia have progressively introduced policy guidelines to promote nutritious food sales in school canteens. This study aimed to assess the compliance of school canteens with their state or territory canteen guidelines.

Methods

School canteen menus from a convenience sample of online government school websites were assessed for compliance with guidelines for the inclusion of foods meeting the criteria for ‘red’ (‘not recommended’ or ‘only occasional – no more than twice per term’), ‘amber’ (‘select carefully’) and ‘green’ (‘always on the menu’, ‘everyday’, ‘fill the menu’ or ‘plenty’). The costs of a salad and a regular pie were also collected where present.

Results

A total of 263 school menus were sourced and assessed (4% of government schools). Western Australia was the most compliant, with 62% of menus adhering to the state guidelines; compliance in other jurisdictions ranged from 5–35%. Compared with primary schools, a higher proportion of secondary schools offered ‘red’ items on the menu (P < 0.05). The mean cost of a regular pie (A$3.17 ± 0.51) was significantly cheaper than the cost of a salad (A$4.25 ± 0.82) (P < 0.001). A range of discretionary food items were present on a large proportion of menus.

Conclusion

This study found that the majority of school canteens were not complying with relevant state or territory guidelines, particularly those schools in which no monitoring or enforcement of the guidelines was conducted.

So what?

Monitoring and enforcement by those responsible for the policy, together with efforts to build the capacity for schools and manufacturers to improve the food supply, may increase compliance.
An exploratory study identifying where local government public health decision makers source their evidence for policy
Authors: Stoneham Melissa , Dodds James
Published: September 2014

Issue addressed

The Western Australian (WA) Public Health Bill will replace the antiquated Health Act 1911. One of the proposed clauses of the Bill requires all WA local governments to develop a Public Health Plan. The Bill states that Public Health Plans should be based on evidence from all levels, including national and statewide priorities, community needs, local statistical evidence, and stakeholder data.

Methods

This exploratory study, which targeted 533 WA local government officers, aimed to identify the sources of evidence used to generate the list of public health risks to be included in local government Public Health Plans.

Results

The top four sources identified for informing local policy were: observation of the consequences of the risks in the local community (24.5%), statewide evidence (17.6%), local evidence (17.6%) and coverage in local media (16.2%).

Conclusions

This study confirms that both hard and soft data are used to inform policy decisions at the local level. Therefore, the challenge that this study has highlighted is in the definition or constitution of evidence.

So what?

Evidence is critical to the process of sound policy development. This study highlights issues associated with what actually constitutes evidence in the policy development process at the local government level. With the exception of those who work in an extremely narrow field, it is difficult for local government officers, whose role includes policymaking, to read the vast amount of information that has been published in their area of expertise. For those who are committed to the notion of evidence‐based policymaking, as advocated within the WA Public Health Bill, this presents a considerable challenge.
Reattendance and chlamydia retesting rates at 12 months among young people attending Australian general practice clinics 2007–10: a longitudinal study
Authors: Weaver Emma R. , Bowring Anna L. , Guy Rebecca , van Gemert Caroline , Hocking Jane S. , Boyle Douglas I. , Merritt Tony , Heal Clare , Lau Phyllis M. , Donovan Basil , Hellard Margaret E.
Published: September 2014

Background Clinical guidelines commonly recommend annual chlamydia (Chlamydia trachomatis) testing in young people. General practice (GP) clinics can play an important role in annual testing, as a high proportion of young people attend these clinics annually; however, little is known about the timing of attendance and testing in this setting. Methods: The Australian Collaboration for Coordinated Enhanced Sentinel Surveillance of Sexually Transmitted Infections and Blood-Borne Viruses system extracted consultation and pathology data on 16–29-year-olds attending 25 GP clinics in 2007–10. We calculated the proportion of individuals with an initial negative test that reattended at 12 months (±3 months) and retested at 12 months (±3 months). Individuals with an initial positive test were excluded, as guidelines recommend retesting at 3 months. Results: Among 3852 individuals who had an initial negative test, 2201 (57.1%) reattended at ~12 months; reattendance was higher among females (60.8%) than males (44.1%; P < 0.001) and higher among 16–19-year-olds (64.2%) than 25–29-year-olds (50.8%; P < 0.001). Of 2201 individuals who reattended at 12 months, 377 had a chlamydia test (retesting rate of 9.8%); retesting was higher among females (10.8%) than males (6.1%; P < 0.01) and higher among 16–19-year-olds (13.3%) than 25–29-year-olds (7.5%; P < 0.001). Conclusion: Although over half of young people reattended their GP clinic ~1 year after a negative chlamydia baseline test, only 9.8% were retested at this visit. Strategies are needed to promote regular attendance and testing to both patients and clinicians.
Novel INHAT Repressor (NIR) is required for early lymphocyte development
Authors: Ma Chi A. , Pusso Antonia , Wu Liming , Zhao Yongge , Hoffmann Victoria , Notarangelo Luigi D. , Fowlkes B. J. , Jain Ashish
Published: September 2014

Significance

Novel inhibitor of histone acetyltransferase repressor (NIR) is a transcriptional corepressor that can bind to p53 at promoters and suppress p53-transcriptional activity by inhibiting histone acetylation. We found that lymphoid-restricted deletion of NIR resulted in the absence of mature B and T lymphocytes, which is partially, but not completely, rescued by the combined deletion of p53 with NIR. Thus, NIR cooperates with p53 to impose a checkpoint for the generation of mature B and T lymphocytes in vivo. Further delineation of additional protein interactions with NIR may lead to the better understanding of the mechanisms that regulate cell-cycle regulation, apoptosis, and lymphocyte differentiation.
Tyrosine phosphorylation of GluK2 up-regulates kainate receptor-mediated responses and downstream signaling after brain ischemia
Authors: Zhu Qiu-Ju , Kong Fan-Shu , Xu Hao , Wang Yi , Du Cai-Ping , Sun Chang-Cheng , Liu Yong , Li Ting , Hou Xiao-Yu
Published: September 2014

Significance

Glutamate is the principal excitatory neurotransmitter in the brain. Kainate receptors, a subfamily of the ionotropic glutamate receptors, mediate the pre- and postsynaptic actions of glutamate. Overactivation of postsynaptic kainate receptors plays an important role in neurodegeneration after ischemic stroke. Because Src kinases show increased activity after brain ischemia, we evaluated their roles in regulating kainate receptor function after brain ischemia. Our results demonstrate that Src kinases bind to and phosphorylate GluK2 at Y590 and facilitate kainate-evoked whole-cell currents and calcium influx. Furthermore, long-term kainate stimulation promotes apoptosis through the endocytosis of GluK2 subunits and activation of JNK3–c-Jun signaling. In summary, our results demonstrate that Src phosphorylation of GluK2 regulates kainate receptor activity and downstream excitatory signaling.
Common genetic variants associated with cognitive performance identified using the proxy-phenotype method
Authors: Rietveld Cornelius A. , Esko Tõnu , Davies Gail , Pers Tune H. , Turley Patrick , Benyamin Beben , Chabris Christopher F. , Emilsson Valur , Johnson Andrew D. , Lee James J. , Leeuw Christiaan de , Marioni Riccardo E. , Medland Sarah E. , Miller Michael B. , Rostapshova Olga , van der Lee Sven J. , Vinkhuyzen Anna A. E. , Amin Najaf , Conley Dalton , Derringer Jaime , van Duijn Cornelia M. , Fehrmann Rudolf , Franke Lude , Glaeser Edward L. , Hansell Narelle K. , Hayward Caroline , Iacono William G. , Ibrahim-Verbaas Carla , Jaddoe Vincent , Karjalainen Juha , Laibson David , Lichtenstein Paul , Liewald David C. , Magnusson Patrik K. E. , Martin Nicholas G. , McGue Matt , McMahon George , Pedersen Nancy L. , Pinker Steven , Porteous David J. , Posthuma Danielle , Rivadeneira Fernando , Smith Blair H. , Starr John M. , Tiemeier Henning , Timpson Nicholas J. , Trzaskowski Maciej , Uitterlinden André G. , Verhulst Frank C. , Ward Mary E. , Wright Margaret J. , Davey Smith George , Deary Ian J. , Johannesson Magnus , Plomin Robert , Visscher Peter M. , Benjamin Daniel J. , Cesarini David , Koellinger Philipp D.
Published: September 2014

Significance

We identify several common genetic variants associated with cognitive performance using a two-stage approach: we conduct a genome-wide association study of educational attainment to generate a set of candidates, and then we estimate the association of these variants with cognitive performance. In older Americans, we find that these variants are jointly associated with cognitive health. Bioinformatics analyses implicate a set of genes that is associated with a particular neurotransmitter pathway involved in synaptic plasticity, the main cellular mechanism for learning and memory. In addition to the substantive contribution, this work also serves to show a proxy-phenotype approach to discovering common genetic variants that is likely to be useful for many phenotypes of interest to social scientists (such as personality traits).