bluuebunny/crossref_metadata_2025 huggingface dataset:
Neurocognition in Psychometrically Defined College Schizotypy Samples: We Are NOT Measuring the “Right Stuff”
Authors: Chun Charlotte A. , Minor Kyle S. , Cohen Alex S.
Published: March 2013

Although neurocognitive deficits are an integral characteristic of schizophrenia, there is inconclusive evidence as to whether they manifest across the schizophrenia-spectrum. We conducted two studies and a meta-analysis comparing neurocognitive functioning between psychometrically defined schizotypy and control groups recruited from a college population. Study One compared groups on measures of specific and global neurocognition, and subjective and objective quality of life. Study Two examined working memory and subjective cognitive complaints. Across both studies, the schizotypy group showed notably decreased subjective (d= 1.52) and objective (d= 1.02) quality of life and greater subjective cognitive complaints (d= 1.88); however, neurocognition was normal across all measures (d's < .35). Our meta-analysis of 33 studies examining neurocognition in at-risk college students revealed between-group differences in the negligible effect size range for most domains. The schizotypy group demonstrated deficits of a small effect size for working memory and set-shifting abilities. Although at-risk individuals report relatively profound neurocognitive deficits and impoverished quality of life, neurocognitive functioning assessed behaviorally is largely intact. Our data suggest that traditionally defined neurocognitive deficits do not approximate the magnitude of subjective complaints associated with psychometrically defined schizotypy. (JINS, 2013,19, 1–14)
Tri-track: Free Software for Large-Scale Particle Tracking
Authors: Vallotton Pascal , Olivier Sandra
Published: March 2013

The ability to correctly track objects in time-lapse sequences is important in many applications of microscopy. Individual object motions typically display a level of dynamic regularity reflecting the existence of an underlying physics or biology. Best results are obtained when this local information is exploited. Additionally, if the particle number is known to be approximately constant, a large number of tracking scenarios may be rejected on the basis that they are not compatible with a known maximum particle velocity. This represents information of a global nature, which should ideally be exploited too. Some time ago, we devised an efficient algorithm that exploited both types of information. The tracking task was reduced to a max-flow min-cost problem instance through a novel graph structure that comprised vertices representing objects from three consecutive image frames. The algorithm is explained here for the first time. A user-friendly implementation is provided, and the specific relaxation mechanism responsible for the method's effectiveness is uncovered. The software is particularly competitive for complex dynamics such as dense antiparallel flows, or in situations where object displacements are considerable. As an application, we characterize a remarkable vortex structure formed by bacteria engaged in interstitial motility.
The Role of Emotions in the Process of Making Choices about Welfare Services: The Experiences of Disabled People in England
Authors: Baxter Kate , Glendinning Caroline
Published: March 2013

Choice is central to developments in many areas of welfare. Making choices, for example about health, social care, employment and housing, can be very emotional. This article draws on theories from experimental psychology and behavioural economics to analyse empirical evidence from a longitudinal, qualitative study of support-related choices. It argues that if people are expected to make emotion-laden choices, and to minimise negative aspects associated with the process of making a choice, they need to be supported in doing so. It contributes to the limited evidence and debate to date about the process costs to individuals of choice.
Die traumatische Milzruptur
Authors: Müller Thomas S. , Sommer Christoph
Published: March 2013

In den vergangenen drei Jahrzehnten kam es in der Behandlung des stumpfen Abdominaltraumas mit Milzverletzung zu einem grundlegenden Paradigma-Wechsel. Während das penetrierende Abdominaltrauma sowie der hämodynamisch instabile Patient mit stumpfem Bauchtrauma eine klare Indikation zur Notfalllaparotomie darstellen, hat sich die Behandlung der hämodynamisch stabilen Patienten entscheidend verändert. Heutzutage werden 80 – 95 % der Patienten erfolgreich mit einem nicht operativen Management (engmaschige Überwachung und allenfalls selten, angiographischer Embolisation) behandelt.
Torsional electric dipole moment functions calculated for HOOH and ClOOCl
Authors: McGrath Mark P.
Published: March 2013

The periodic torsional, electric dipole moment (EDM) functions μ(ϕ) = ∑m = 0pmcos (m + 1/2)ϕ, of the atmospherically significant molecules HOOH and ClOOCl, have been derived from calculations at the CCSD(T) (coupled-cluster singles and doubles model, plus a noniterative triples correction) level of electronic-structure theory with augmented, correlation-consistent basis sets extrapolated to the approximate complete basis set limit. The μ(ϕ) of HOOH, defined by {pm} = {3.0979, −0.0301, −0.0058} D, is used to calculate squared transition EDMs that compare well with those previously derived using the experimental torsional line intensities. The μ(ϕ) of ClOOCl, defined by μ(ϕ) = {1.1935, 0.1163, 0.1341, −0.0040, −0.0099} D, requires a longer Fourier expansion because, in the range of dihedral angles from the cis (ϕ = 0) to the trans (ϕ = π) transition structures, three inflection points are found for ClOOCl, but only one for HOOH. The permanent EDM calculated for HOOH, 1.754 D, is in close agreement with the value deduced from experiment. Compared to HOOH, the permanent EDM vector calculated for ClOOCl is directed analogously, but has a significantly smaller magnitude, 0.700 D.
Extension of the KLI approximation toward the exact optimized effective potential
Authors: Iafrate G. J. , Krieger J. B.
Published: March 2013

The integral equation for the optimized effective potential (OEP) is utilized in a compact form from which an accurate OEP solution for the spin-unrestricted exchange-correlation potential, Vxcσ, is obtained for any assumed orbital-dependent exchange-correlation energy functional. The method extends beyond the Krieger-Li-Iafrate (KLI) approximation toward the exact OEP result. The compact nature of the OEP equation arises by replacing the integrals involving the Green's function terms in the traditional OEP equation by an equivalent first-order perturbation theory wavefunction often referred to as the “orbital shift” function. Significant progress is then obtained by solving the equation for the first order perturbation theory wavefunction by use of Dalgarno functions which are determined from well known methods of partial differential equations. The use of Dalgarno functions circumvents the need to explicitly address the Green's functions and the associated problems with “sum over states” numerics; as well, the Dalgarno functions provide ease in dealing with inherent singularities arising from the origin and the zeros of the occupied orbital wavefunctions. The Dalgarno approach for finding a solution to the OEP equation is described herein, and a detailed illustrative example is presented for the special case of a spherically symmetric exchange-correlation potential. For the case of spherical symmetry, the relevant Dalgarno function is derived by direct integration of the appropriate radial equation while utilizing a user friendly method which explicitly treats the singular behavior at the origin and at the nodal singularities arising from the zeros of the occupied states. The derived Dalgarno function is shown to be an explicit integral functional of the exact OEP Vxcσ, thus allowing for the reduction of the OEP equation to a self-consistent integral equation for the exact exchange-correlation potential; the exact solution to this integral equation can be determined by iteration with the natural zeroth order correction given by the KLI exchange-correlation potential. Explicit analytic results are provided to illustrate the first order iterative correction beyond the KLI approximation. The derived correction term to the KLI potential explicitly involves spatially weighted products of occupied orbital densities in any assumed orbital-dependent exchange-correlation energy functional; as well, the correction term is obtained with no adjustable parameters. Moreover, if the equation for the exact optimized effective potential is further iterated, one can obtain the OEP as accurately as desired.
A poly(dimethylsiloxane) based prism for surface plasmon resonance imaging system and its application for gas detection
Authors: Zhang L. L. , Chen X. , Sun J. H. , Cai H. Y. , Li H. , Chao Y. P. , Cui D. F.
Published: March 2013

This paper presents a surface plasmon resonance (SPR) imaging system based on a low-cost, convenient poly(dimethylsiloxane) (PDMS) prism featured with a close contact with the gold film. Compared to conventional glass prism, both numerical simulations and experimental studies indicated a deeper but wider absorption peak with a higher coupling angle for the PDMS based prism. System repeatability was quantified by the cycled detection of helium and air, with the effect of the flow rate investigated. Furthermore, five types of gases (nitrogen, air, oxygen, hydrogen, and helium) were detected and differentiated by the SPR system, with a calculated sensitivity of 5 × 10−6 RIU.
Localized saddle-point search and application to temperature-accelerated dynamics
Authors: Shim Yunsic , Callahan Nathan B. , Amar Jacques G.
Published: March 2013

We present a method for speeding up temperature-accelerated dynamics (TAD) simulations by carrying out a localized saddle-point (LSAD) search. In this method, instead of using the entire system to determine the energy barriers of activated processes, the calculation is localized by only including a small chunk of atoms around the atoms directly involved in the transition. Using this method, we have obtained N-independent scaling for the computational cost of the saddle-point search as a function of system size N. The error arising from localization is analyzed using a variety of model systems, including a variety of activated processes on Ag(100) and Cu(100) surfaces, as well as multiatom moves in Cu radiation damage and metal heteroepitaxial growth. Our results show significantly improved performance of TAD with the LSAD method, for the case of Ag/Ag(100) annealing and Cu/Cu(100) growth, while maintaining a negligibly small error in energy barriers.
Pressure induced dimer to ionic insulator and metallic structural changes in Al2Br6
Authors: Yao Yansun , Klug Dennis D.
Published: March 2013

High-pressure phase transitions in Al2Br6 were theoretically investigated using first principles density functional methods. A structural transformation from the initial molecular solid phase to a planar polymeric phase is predicted near 0.4 GPa that is accompanied with a substantial volume drop. A unique feature of this phase transition is that the hcp lattice of Br atoms remains unchanged during the transition, whereas the Al atoms are displaced from the original tetrahedral sites to the octahedral sites. The calculated phonon spectra indicate that the predicted phase is mechanically stable at 1 atm, and therefore it may be quench-recovered to ambient conditions and exist as a metastable form. A second structural transformation is predicted to occur at around 80 GPa, and also at this point, the AlBr3 reaches a metallic state. The electronic structure of the metallic phase features soft phonon modes and Fermi surface nesting in the Brillouin zone, which leads to localized electron-phonon coupling. By comparing with the experimental data available for high-pressure BI3, the superconducting critical temperature Tc for the metallic phase of AlBr3 is estimated to be at 0.5 K or above.
Spin filtering in molecular junction: Magnetoresistance evaluation from wave-function calculations
Authors: Vérot Martin , Borshch Serguei A. , Robert Vincent
Published: March 2013

The conductance of magnetic molecules opens new ways to probe the electronic structure of correlated systems. Based on a 2-electron/2-molecular orbital prototype system, the current-potential characteristics is inspected as a function of the differential magnetization of the electrodes sandwiching the molecule within a multideterminantal framework. The bias-dependent magnetoresistance effect along the junction reflects the nature and energetics of the different multiplets, obtained within the multiconfigurational wave-function approach. From the wave-function description, a modulation of the magnetoresistance ratio is anticipated and both direct and inverse regimes are observed depending on the electronic structure of the junction.
Rate coefficients and kinetic isotope effects of the X + CH4 → CH3 + HX (X = H, D, Mu) reactions from ring polymer molecular dynamics
Authors: Li Yongle , Suleimanov Yury V. , Li Jun , Green William H. , Guo Hua
Published: March 2013

The thermal rate coefficients and kinetic isotope effects have been calculated using ring polymer molecular dynamics (RPMD) for the prototypical reactions between methane and several hydrogen isotopes (H, D, and Mu). The excellent agreement with the theoretical rate coefficients of the H + CH4 reaction obtained previously from a multi-configuration time-dependent Hartree calculation on the same potential energy surface provides strong evidence for the accuracy of the RPMD approach. These quantum mechanical rate coefficients are also in good agreement with the results obtained previously using the transition-state theory with semi-classical tunneling corrections for the H/D + CH4 reactions. However, it is shown that the RPMD rate coefficients for the ultralight Mu reaction with CH4 are significantly smaller than the experimental data, presumably suggesting inaccuracies in the potential energy surface and/or experimental errors. Significant discrepancies between the RPMD and transition-state theory results have also been found for this challenging system.
Disorder-tuned charge transport in organic semiconductors
Authors: Xu Feng , Qiu Dong , Yan Dadong
Published: March 2013

We propose that the polaron transport in organic semiconductors is remarkably tuned by the fluctuation of polarization energy. The tuning effect of energetic fluctuation not only causes a continuous transition from non-Arrhenius to Arrhenius temperature activated charge transport with increasing moderate disorder strengths but also results in a band-like conduction in the low disorder regime which benefits from the enhanced mobilities in shallow trap states. As a result, a unified description of polaron transport is obtained for a set of typical organic semiconductors.
Mixing of equations of state for xenon-deuterium using density functional theory
Authors: Magyar Rudolph J. , Mattsson Thomas R.
Published: March 2013

We report on a theoretical study of equation of state (EOS) properties of fluid and dense plasma mixtures of xenon and deuterium to explore and illustrate the basic physics of the mixing of a light element with a heavy element. Accurate EOS models are crucial to achieve high-fidelity hydrodynamics simulations of many high-energy-density phenomena, for example inertial confinement fusion and strong shock waves. While the EOS is often tabulated for separate species, the equation of state for arbitrary mixtures is generally not available, requiring properties of the mixture to be approximated by combining physical properties of the pure systems. Density functional theory (DFT) at elevated-temperature is used to assess the thermodynamics of the xenon-deuterium mixture at different mass ratios. The DFT simulations are unbiased as to elemental species and therefore provide comparable accuracy when describing total energies, pressures, and other physical properties of mixtures as they do for pure systems. The study focuses on addressing the accuracy of different mixing rules in the temperature range 1000–40 000 K for pressures between 100 and 600 GPa (1–6 Mbar), thus, including the challenging warm dense matter regime of the phase diagram. We find that a mix rule taking into account pressure equilibration between the two species performs very well over the investigated range.
Coherent synchrotron radiation for broadband terahertz spectroscopy
Authors: Barros J. , Evain C. , Manceron L. , Brubach J.-B. , Tordeux M.-A. , Brunelle P. , Nadolski L. , Loulergue A. , Couprie M.-E. , Bielawski S. , Szwaj C. , Roy P.
Published: March 2013

We present the first high resolution (10−3 cm−1) interferometric measurements in the 200–750 GHz range using coherent synchrotron radiation, achieved with a low momentum compaction factor. The effect of microbunching on spectra is shown, depending on the bunch current. A high signal-to-noise ratio is reached thanks to an artifact correction system based on a double detection scheme. Combined to the broad emitted spectral range and high flux (up to 105 times the incoherent radiation), this study demonstrates that coherent synchrotron radiation can now be used for stability-demanding applications, such as gas-phase studies of unstable molecules.
Effect of stoichiometry on the dielectric properties and soft mode behavior of strained epitaxial SrTiO3 thin films on DyScO3 substrates
Authors: Lee Che-Hui , Skoromets Volodymyr , Biegalski Michael D. , Lei Shiming , Haislmaier Ryan , Bernhagen Margitta , Uecker Reinhard , Xi Xiaoxing , Gopalan Venkatraman , Martí Xavier , Kamba Stanislav , Kužel Petr , Schlom Darrell G.
Published: March 2013

The effect of stoichiometry on the dielectric properties and soft mode behavior of strained epitaxial Sr1+xTiO3+δ films grown on DyScO3 substrates is reported. Direct comparisons between nominally stoichiometric and non-stoichiometric films have been performed through measurements of lattice parameters, temperature-dependent permittivities, second harmonic generation, and terahertz dielectric spectra. The nominally stoichiometric film shows dispersion-free low-frequency permittivity with a sharp maximum and pronounced soft mode behavior. Our results suggest that strained perfectly stoichiometric SrTiO3 films should not show relaxor behavior and that relaxor behavior emerges from defect dipoles that arise from non-stoichiometry in the highly polarizable strained SrTiO3 matrix.
Electrical modulation of emissivity
Authors: Vassant S. , Moldovan Doyen I. , Marquier F. , Pardo F. , Gennser U. , Cavanna A. , Pelouard J. L. , Greffet J. J.
Published: March 2013

We demonstrate that it is possible to modulate the thermal emission through an electrical modulation of the emissivity. The basic idea is to design a device where absorption is due to a resonant phenomenon. If the resonance can be electrically controlled, then absorption and, therefore, thermal emission can be controlled. We demonstrate this general concept using THz resonant absorption by surface phonon polaritons coupled through a gold grating. In our device, absorption is mostly due to a surface phonon mode confined in a single quantum well (QW). The THz emissivity is electrically controlled by controlling the quantum well refractive index using a gate voltage to modulate the electron density. This paves the way to electrically modulated incandescent sources.
Integrated photonics on silicon with wide bandgap GaN semiconductor
Authors: Vico Triviño N. , Dharanipathy U. , Carlin J.-F. , Diao Z. , Houdré R. , Grandjean N.
Published: March 2013

We report on GaN self-supported photonic structures consisting in freestanding waveguides coupled to photonic crystal waveguides and cavities operating in the near-infrared. GaN layers were grown on Si (111) by metal organic vapor phase epitaxy. E-beam lithography and dry etching techniques were employed to pattern the GaN layer and undercut the substrate. The combination of low-absorption in the infrared range and improved etching profiles results in cavities with quality factors as high as ∼5400. The compatibility with standard Si technology should enable the development of low cost photonic devices for optical communications combining wide-bandgap III-nitride semiconductors and silicon.
Non-specular reflections in a macroscopic system with wave-particle duality: Spiral waves in bounded media
Authors: Langham Jacob , Barkley Dwight
Published: March 2013

Spiral waves in excitable media possess both wave-like and particle-like properties. When resonantly forced (forced at the spiral rotation frequency) spiral cores travel along straight trajectories, but may reflect from medium boundaries. Here, numerical simulations are used to study reflections from two types of boundaries. The first is a no-flux boundary which waves cannot cross, while the second is a step change in the medium excitability which waves do cross. Both small-core and large-core spirals are investigated. The predominant feature in all cases is that the reflected angle varies very little with incident angle for large ranges of incident angles. Comparisons are made to the theory of Biktashev and Holden. Large-core spirals exhibit other phenomena such as binding to boundaries. The dynamics of multiple reflections is briefly considered.
Tunneling field-effect transistor with Ge/In0.53Ga0.47As heterostructure as tunneling junction
Authors: Guo Pengfei , Yang Yue , Cheng Yuanbing , Han Genquan , Pan Jisheng , Ivana  , Zhang Zheng , Hu Hailong , Xiang Shen Ze , Kean Chia Ching , Yeo Yee-Chia
Published: March 2013

High quality epitaxial germanium (Ge) was successfully grown on In0.53Ga0.47As substrate using a metal-organic chemical vapor deposition tool. The valence band offset ΔEV between the Ge layer and In0.53Ga0.47As determined by high-resolution x-ray photoelectron spectroscopy was found to be 0.5 ± 0.1 eV, suggesting the Ge/In0.53Ga0.47As heterojunction has a staggered band alignment at the interface. This makes the Ge/In0.53Ga0.47As heterojunction a promising tunneling junction for application in tunneling field-effect transistor (TFET). Lateral TFET with in situ doped p+ Ge-source In0.53Ga0.47As-channel using a gate-last process was demonstrated for the first time. The temperature dependence of the TFET transfer characteristics was investigated. The TFET with gate length (LG) of 8 μm exhibits an on-state tunneling current (ION) of 380 nA/μm at VGS = VDS = 2 V. The subthreshold swing (S) at the steepest part of the transfer characteristics of this device is ∼177 mV/decade. It was found that the off-state leakage current (IOFF) was determined by the Shockley-Read-Hall generation-recombination current in the Ge-source region. The temperature dependence of ION was mainly due to the change of the band gap with temperature. Furthermore, S was found to be limited by the trap-assisted tunneling at the Ge/In0.53Ga0.47As tunneling junction. The low ION and poor S can be enhanced by improving the source/channel profile and optimizing Ge epitaxial growth process.
Electrostrictive and relaxor ferroelectric behavior in BiAlO3-modified BaTiO3 lead-free ceramics
Authors: Zheng Shaoying , Odendo Erika , Liu Laijun , Shi Danping , Huang Yanming , Fan Longlong , Chen Jun , Fang Liang , Elouadi Brahim
Published: March 2013

The crystal structure of (1−x)BaTiO3-xBiAlO3 (x = 0, 0.02, 0.05, 0.08, and 0.1) ceramics was determined using X-ray diffraction and Raman spectroscopy at room temperature, which revealed a phase transition from tetragonal to rhombohedral with increasing x. The dielectric properties were studied as a function of temperature at different frequencies, which indicated that the phase transition temperature (Tm) decreased with increasing x. The relaxor behavior was observed by frequency and temperature dependent dielectric permittivity. The Lorenz-type quadratic law was used to characterize the dielectric permittivity peaks near Tm of high-temperature slopes at 1 MHz. The temperatures Tm of dielectric permittivity peaks fit very well with the Vogel-Fulcher law in x = 0.05 and x = 0.1. The polarization hysteresis loops and electrostrictive were displayed at room temperature. The sample for x = 0.1 exhibits a slim loop with negligible hysteresis and a subtle linear feature, which is a promising transducer material for use as an active element.
Terahertz nonlinear superconducting metamaterials
Authors: Zhang Caihong , Jin Biaobing , Han Jiaguang , Kawayama Iwao , Murakami Hironaru , Wu Jingbo , Kang Lin , Chen Jian , Wu Peiheng , Tonouchi Masayoshi
Published: March 2013

We investigate the nonlinear effect of a planar superconducting metamaterial made from niobium nitride (NbN) at terahertz frequencies. As the variation of the incident intense terahertz field alters the intrinsic conductivity in the NbN, a consequent giant amplitude modulation is observed due to the strong nonlinearities. The high sensitivity of the chosen metamaterial even allows observing the nonlinear behaviors at various temperatures, but the resonance modulation induced by the nonlinear effect was distinct from that induced by the heating effect. The presented results illustrate a clever implementation of strongly enhanced nonlinearities and thus may bring nonlinear metamaterials into novel applications.
Relationship of microstructure properties to oxygen impurities in nanocrystalline silicon photovoltaic materials
Authors: Xu H. , Wen C. , Liu H. , Li Z. P. , Shen W. Z.
Published: March 2013

We have fully investigated the correlation of microstructure properties and oxygen impurities in hydrogenated nanocrystalline silicon photovoltaic films. The achievement has been realized through a series of different hydrogen dilution ratio treatment by plasma enhanced chemical vapor deposition system. Raman scattering, x-ray diffraction, and ultraviolet-visible transmission techniques have been employed to characterize the physical structural characterization and to elucidate the structure evolution. The bonding configuration of the oxygen impurities was investigated by x-ray photoelectron spectroscopy and the Si-O stretching mode of infrared-transmission, indicating that the films were well oxidized in SiO2 form. Based on the consistence between the proposed structure factor and the oxygen content, we have demonstrated that there are two dominant disordered structure regions closely related to the post-oxidation contamination: plate-like configuration and clustered microvoids.
Entropic depletion of DNA in triangular nanochannels
Authors: Reinhart Wesley F. , Tree Douglas R. , Dorfman Kevin D.
Published: March 2013

Using Monte Carlo simulations of a touching-bead model of double-stranded DNA, we show that DNA extension is enhanced in isosceles triangular nanochannels (relative to a circular nanochannel of the same effective size) due to entropic depletion in the channel corners. The extent of the enhanced extension depends non-monotonically on both the accessible area of the nanochannel and the apex angle of the triangle. We also develop a metric to quantify the extent of entropic depletion, thereby collapsing the extension data for circular, square, and various triangular nanochannels onto a single master curve for channel sizes in the transition between the Odijk and de Gennes regimes.
Effects of deep-level dopants on the electronic potential of thin Si pn junctions observed by Kelvin probe force microscope
Authors: Nowak Roland , Moraru Daniel , Mizuno Takeshi , Jablonski Ryszard , Tabe Michiharu
Published: March 2013

Electronic potential measurements performed by low-temperature Kelvin probe force microscopy on silicon-on-insulator lateral nanoscale pn junctions are presented. The electronic potential landscape contains a region of enhanced potential induced by interdiffused dopants with deeper ground-state levels compared to bulk. The discrete dopant distribution can be observed in specific line profiles. In most line profiles, time-dependent potential fluctuations due to charging and discharging of dopants give rise to a localized-noise area corresponding to the depletion region.
Resistive switching characteristics of Pt/TaOx/HfNx structure and its performance improvement
Authors: Zhou Qigang , Zhai Jiwei
Published: March 2013

The refractory transition metal nitride (TMN) film Hafnium nitride (HfNx) was successfully prepared on silicon-based substrates as bottom electrodes for resistive random access memory (RRAM) cells in Pt (top)/metal oxide/ HfNx (bottom) sandwich structure. The reproducible resistive switching (RS) characteristics of the memory cells were studied systematically for RRAM applications. The advantages of adopting HfNx instead of Pt as bottom electrode material were demonstrated, including the improvement of the low resistive state value, the RS endurance and the uniformity of RS parameters. The composition and chemical bonding states of the prepared HfNx was analyzed by X-ray photoelectron spectroscopy (XPS) technique. The nitrogen content in the HfNx and the Gibbs free energy of the corresponding metal oxide formation has great influences on the RS properties. The oxygen reservoir ability and diffusion barrier effect of the HfNx play a key role in the RS performance improvement of the RRAM devices.
Thermoelectric properties of chalcogenide based Cu2+xZnSn1−xSe4
Authors: Raju Ch. , Falmbigl M. , Rogl P. , Yan X. , Bauer E. , Horky J. , Zehetbauer M. , Chandra Mallik Ramesh
Published: March 2013

Quaternary chalcogenide compounds Cu2+xZnSn1−xSe4 (0 ≤ x ≤ 0.15) were prepared by solid state synthesis. Rietveld powder X-ray diffraction (XRD) refinements combined with Electron Probe Micro Analyses (EPMA, WDS-Wavelength Dispersive Spectroscopy) and Raman spectra of all samples confirmed the stannite structure (Cu2FeSnS4-type) as the main phase. In addition to the main phase, small amounts of secondary phases like ZnSe, CuSe and SnSe were observed. Transport properties of all samples were measured as a function of temperature in the range from 300 K to 720 K. The electrical resistivity of all samples decreases with an increase in Cu content except for Cu2.1ZnSn0.9Se4, most likely due to a higher content of the ZnSe. All samples showed positive Seebeck coefficients indicating that holes are the majority charge carriers. The thermal conductivity of doped samples was high compared to Cu2ZnSnSe4 and this may be due to the larger electronic contribution and the presence of the ZnSe phase in the doped samples. The maximum zT = 0.3 at 720 K occurs for Cu2.05ZnSn0.95Se4 for which a high-pressure torsion treatment resulted in an enhancement of zT by 30% at 625 K.
Loss of ALS-associated TDP-43 in zebrafish causes muscle degeneration, vascular dysfunction, and reduced motor neuron axon outgrowth
Authors: Schmid Bettina , Hruscha Alexander , Hogl Sebastian , Banzhaf-Strathmann Julia , Strecker Katrin , van der Zee Julie , Teucke Mathias , Eimer Stefan , Hegermann Jan , Kittelmann Maike , Kremmer Elisabeth , Cruts Marc , Solchenberger Barbara , Hasenkamp Laura , van Bebber Frauke , Van Broeckhoven Christine , Edbauer Dieter , Lichtenthaler Stefan F. , Haass Christian
Published: March 2013

Mutations in the Tar DNA binding protein of 43 kDa (TDP-43; TARDBP) are associated with amyotrophic lateral sclerosis (ALS) and frontotemporal lobar degeneration with TDP-43+inclusions (FTLD-TDP). To determine the physiological function of TDP-43, we knocked out zebrafish Tardbp and its paralogue Tardbp (TAR DNA binding protein-like), which lacks the glycine-rich domain where ALS- and FTLD-TDP–associated mutations cluster.tardbpmutants show no phenotype, a result of compensation by a unique splice variant oftardbplthat additionally contains a C-terminal elongation highly homologous to the glycine-rich domain oftardbp. Double-homozygous mutants oftardbpandtardbplshow muscle degeneration, strongly reduced blood circulation, mispatterning of vessels, impaired spinal motor neuron axon outgrowth, and early death. In double mutants the muscle-specific actin binding protein Filamin Ca is up-regulated. Strikingly,Filamin Cis similarly increased in the frontal cortex of FTLD-TDP patients, suggesting aberrant expression in smooth muscle cells and TDP-43 loss-of-function as one underlying disease mechanism.
Military business and the business of the military in the Kivus
Authors: Verweijen Judith
Published: March 2013

Contrary to dominant approaches that locate the causes for military entrepreneurialism in eastern Democratic Republic of the Congo predominantly in criminal military elites, this article highlights the importance of the Congolese military's (FARDC) civilian context for understanding military revenue-generation. It analyses how the latter is shaped by structures of domination, signification and legitimisation that drive and are driven by the FARDC's governance, private protection and security practices. It argues that these practices contribute to bestowing a degree of legitimacy on both the FARDC's position of power and some of its revenue-generation activities. Furthermore, by emphasising that the FARDC's regulatory and protection practices are partly the product of popular demands and the routine actions of civilians, the article contends that the causes of military revenue-generation are co-located in the military's civilian environment. In this manner, it offers a more nuanced conceptualisation of military entrepreneurialism, thus opening up new perspectives on policy interventions in this area.

[Les affaires militaires et les affaires des militaires dans le Kivu]. Contrairement aux approches dominantes qui trouvent les causes de l'entrepreneuriat des militaires dans l'est de la RDC essentiellement dans les élites militaires criminelles, cet article met en exergue l'importance du contexte civil de l'armée congolaise (FARDC) pour comprendre les pratiques militaires génératrices de revenus. Il analyse comment ces dernières sont influencées par les structures de domination, de signification et de légitimation qui conduisent et sont conduites par les pratiques de gouvernance, de protection privée et de sécurité des FARDC. L'article soutient que ces pratiques contribuent à l'attribution d'un degré de légitimité tant sur la position du pouvoir des FARDC que sur certaines de leurs activités de génération de revenus. En outre, en insistant sur le fait que les pratiques de protection et de régulation des FARDC résultent en partie des demandes populaires et des actions de routine des civils, l'article soutient que les origines des activités de génération de revenus des militaires sont co-localisés dans l'environnement civil des militaires. De cette manière, l'article offre une conceptualisation de l'entreprenariat militaire plus nuancé, ouvrant ainsi de nouvelles perspectives pour les interventions des bailleurs de fonds dans ce domaine.

Mots-clés : Armée congolaise ; Kivu ; militarisation ; économies informelles ; réforme de l'armée
God and Caesar in the Democratic Republic of Congo: negotiating church–state relations through the management of school fees in Kinshasa's Catholic schools
Authors: Titeca Kristof , De Herdt Tom , Wagemakers Inge
Published: March 2013

This article argues that state (re)construction and functioning involves negotiated governance between both state and non-state actors, in which power relations between local actors are not just implicitly present or co-influencing policies but are of uttermost importance to the formation of policy and state. One of the main non-state actors in African service delivery is the church. State and church are two major poles of power which determine – through negotiation – large domains of service delivery, such as education. We discuss a major attempt by the Catholic Church to reform the school-fee system in Kinshasa (DRC). The attempt largely failed, but its analysis reveals the political capabilities of different actors involved. The arrangements of state and non-state actors largely evolve in a roundabout way, not at all along the lines of an explicit negotiation process, and are very much determined by local-level governance instead of higher-level policies.

[Dieu et César dans la République Démocratique du Congo : les négociations des relations entre l'église et l'état à travers l'administration des frais de scolarité dans les écoles Catholiques de Kinshasa.] Cet article soutient que la (re)construction de l'État et son fonctionnement impliquent une gouvernance négociée tant entre les acteurs étatiques et non-étatiques, et dans laquelle les relations de pouvoir ne sont pas seulement présentes implicitement ou ne font pas qu'influencer conjointement les politiques, mais sont d'importance capitale à la formation de la politique et de l'État. Un des acteurs non-étatiques principaux dans la fourniture de service en Afrique est l'Église. L'État et l'Église sont deux pôles importants de pouvoir qui déterminent - par la négociation - les grands domaines de fourniture de services, comme l'éducation. Cette étude examine une tentative de réforme majeure du système des frais scolaires à Kinshasa (RDC) par l'Église catholique. La tentative a échoué en grande partie, mais son analyse révèle les capacités politiques des différents acteurs impliqués. Les accords des acteurs étatiques et non-étatiques se développent majoritairement d'une manière détournée, pas du tout dans le sens d'un processus de négociation explicite, et sont très largement déterminées par la gouvernance au niveau local à défaut de politiques d'un niveau supérieur.

Mots-clés : République Démocratique du Congo ; l'État ; l'Église ; gouvernance ; secteur éducatif
Is the Relationship between Pattern Recall and Decision-Making Influenced by Anticipatory Recall?
Authors: Gorman Adam D. , Abernethy Bruce , Farrow Damian
Published: March 2013

The present study compared traditional measures of pattern recall to measures of anticipatory recall and decision-making to examine the underlying mechanisms of expert pattern perception and to address methodological limitations in previous studies where anticipatory recall has generally been overlooked. Recall performance in expert and novice basketball players was measured by examining the spatial error in recalling player positions both for a target image (traditional recall) and at 40-ms increments following the target image (anticipatory recall). Decision-making performance was measured by comparing the participant's response to those identified by a panel of expert coaches. Anticipatory recall was observed in the recall task and was significantly more pronounced for the experts, suggesting that traditional methods of spatial recall analysis may not have provided a completely accurate determination of the full magnitude of the experts' superiority. Accounting for anticipatory recall also increased the relative contribution of recall skill to decision-making accuracy although the gains in explained variance were modest and of debatable functional significance.
ChIP-PED enhances the analysis of ChIP-seq and ChIP-chip data
Authors: Wu George , Yustein Jason T. , McCall Matthew N. , Zilliox Michael , Irizarry Rafael A. , Zeller Karen , Dang Chi V. , Ji Hongkai
Published: March 2013

Motivation: Although chromatin immunoprecipitation coupled with high-throughput sequencing (ChIP-seq) or tiling array hybridization (ChIP-chip) is increasingly used to map genome-wide–binding sites of transcription factors (TFs), it still remains difficult to generate a quality ChIPx (i.e. ChIP-seq or ChIP-chip) dataset because of the tremendous amount of effort required to develop effective antibodies and efficient protocols. Moreover, most laboratories are unable to easily obtain ChIPx data for one or more TF(s) in more than a handful of biological contexts. Thus, standard ChIPx analyses primarily focus on analyzing data from one experiment, and the discoveries are restricted to a specific biological context.

Results: We propose to enrich this existing data analysis paradigm by developing a novel approach, ChIP-PED, which superimposes ChIPx data on large amounts of publicly available human and mouse gene expression data containing a diverse collection of cell types, tissues and disease conditions to discover new biological contexts with potential TF regulatory activities. We demonstrate ChIP-PED using a number of examples, including a novel discovery that MYC, a human TF, plays an important functional role in pediatric Ewing sarcoma cell lines. These examples show that ChIP-PED increases the value of ChIPx data by allowing one to expand the scope of possible discoveries made from a ChIPx experiment.

Availability:  http://www.biostat.jhsph.edu/∼gewu/ChIPPED/

Contact:  hji@jhsph.edu

Supplementary information:  Supplementary data are available at Bioinformatics online.
Resolving Whistleblowing Disputes in the Public Interest: Is Tribunal Adjudication the Best that Can be Offered?
Authors: Lewis David
Published: March 2013

This article argues that employment tribunal adjudication may be both a difficult and ineffective mechanism for resolving whistleblowing disputes. The author asserts that, if disclosures of serious wrongdoing are to be encouraged, both the law and dispute resolution mechanisms need to be improved. Ideally, employers should have whistleblowing procedures which provide for conciliation, mediation and arbitration as alternative forms of redress for those who feel that their disclosures have not been dealt with properly or have allegedly suffered retaliation. Recognising that a legal obligation to have effective whistleblowing arrangements is unlikely to be imposed by law, the author suggests that alternative dispute resolution mechanisms should be made available where whistleblowing claims are lodged with employment tribunals.
Hardness Changes and Endosperm Modification During Sorghum Malting in Grains of Varying Hardness and Malt Quality
Authors: Chiremba Constance , Siwela Muthulisi , Rooney Lloyd W. , Taylor John R. N.
Published: March 2013

This study examined the interaction between sorghum grain hardness and sorghum malt quality in terms of diastatic power and free amino nitrogen with endosperm modification during malting. The changes in kernel hardness during malting of four commercial sorghum cultivars of differing quality in terms of endosperm texture and potential malt quality were measured using tests for hardness and density, and endosperm modification was followed by scanning electron microscopy. The general pattern of modification during sorghum malting was confirmed to start at the endosperm–scutellum interface and then continue into the floury endosperm toward the kernel distal end. Significantly, a cultivar of intermediate hardness and low malting quality remained harder and modified more slowly than a harder cultivar of high malting quality. It appeared that intrinsic grain hardness and malt amylase and protease activity both affected malt hardness and endosperm modification, but amylase and protease activity had a greater effect because of their degradation of endosperm starch and protein. Of the hardness and density tests studied, the tangential abrasive dehulling device (TADD) gave the best measure of hardness throughout malting; maximum range was 24–100% kernel removed over five days of malting. Also, the data agreed with the observed malt modification rates. Thus, the TADD may have application as a simple and rapid test for estimating sorghum malt quality.
The RNase Protection Assay
Authors: Carey Michael F. , Peterson Craig L. , Smale Stephen T.
Published: March 2013

The RNase protection assay is a sensitive method for transcription start-site localization. It begins with an RNA probe that is uniformly labeled by incorporation of one [α-32P]NTP, usually [α-32P]UTP. The RNA probe is synthesized by bacteriophage RNA polymerase (SP6, T7, or T3), which initiates transcription from specific phage promoters that have been engineered into a number of common plasmid vectors. The plasmid template contains a genomic DNA fragment spanning the region thought to contain the transcription start site for the gene of interest. This genomic fragment is subcloned into the plasmid downstream of the phage promoter in the antisense orientation, so that a portion of the 5′ end of the resulting RNA probe will be complementary to the mRNA of interest. The radiolabeled probe is annealed to cytoplasmic or total cellular mRNA purified from the cells of interest, with the hybridization reaction proceeding for several hours or overnight. RNase A and/or RNase T1 is then added to the hybridization reactions. These nucleases digest the single-stranded overhang regions of RNA molecules, but RNA–RNA hybrids are resistant to cleavage. This resistance forms the conceptual basis for the procedure; the region of the probe that anneals to the specific mRNA will be resistant to digestion. The length of the resistant region of the probe will correspond to the distance from the 5′ end of the probe to the transcription start site. The size of the resistant fragment can be determined by electrophoresis on a high-resolution, denaturing polyacrylamide gel.
Nuclear Microinjection to Assess How Heterologously Expressed Proteins Impact Ca2+ Signals in Xenopus Oocytes
Authors: Lin-Moshier Yaping , Marchant Jonathan S.
Published: March 2013

The Xenopus oocyte is frequently used for heterologous expression and for studying the spatiotemporal patterning of Ca2+ signals. Here, we outline a protocol for nuclear microinjection of the Xenopus oocyte for the purpose of studying how subsequently expressed proteins impact intracellular Ca2+ signals evoked by inositol trisphosphate (InsP3). Injected oocytes can easily be identified by reporter technologies and the impact of heterologously expressed proteins on the generation and properties of InsP3-evoked Ca2+ signals can be resolved using caged InsP3 and fluorescent Ca2+ indicators.
Imaging Retinal Progenitor Lineages in Developing Zebrafish Embryos
Authors: Jusuf Patricia , Harris William A. , Poggi Lucia
Published: March 2013

In this protocol, we describe how to make and analyze four dimensional (4D) movies of retinal lineage in the zebrafish embryo in vivo. 4D consists of three spatial dimensions (3D) reconstructed from stacks of confocal planes plus one time dimension. Our imaging is performed on transgenic cells that express fluorescent proteins under the control of cell-specific promoters or on cells that transiently express such reporters in specific retinal cell progenitors. An important aspect of lineage tracing is the ability to follow individual cells as they undergo multiple cell divisions, final migration, and differentiation. This may mean many hours of 4D imaging, requiring that cells be kept healthy and maintained under conditions suitable for normal development. The longest movies we have made are ∼50 h. By analyzing these movies, we can see when a specific cell was born and who its sister was, allowing us to reconstruct its retinal lineages in vivo.
Detecting RNA–Protein Interactions by Photocross-Linking Using RNA Molecules Containing Uridine Analogs
Authors: Nilsen Timothy W.
Published: March 2013

Various cross-linking techniques form covalent attachments between proteins and RNAs. Straight ultraviolet (UV) cross-linking using short-wavelength UV light is inherently very inefficient. Therefore, it is often desirable to increase the efficiency of cross-linking. The uridine analogs 4-thiouridine and halogenated uridine (5-bromouridine or 5-iodouridine) are much more photoreactive than uridine. Accordingly, RNAs substituted with these bases are quite effective for cross-linking applications. This protocol describes the detection of RNA–protein interactions by photocross-linking using RNA molecules containing 4-thiouridine, but identical procedures apply to using 5-bromouridine or 5-iodouridine. Fully substituted RNAs are useful in determining whether any proteins interact with the RNA of interest. However, it may be preferable to use site-specifically substituted RNA if one has foreknowledge of critical regions in the RNA of interest. For any cross-linking application using substituted RNA, it is essential to remember that the uridine analogs are activated at a wavelength >304 nm (312 nm) than is used for short-wavelength (254 nm) cross-linking.