bluuebunny/crossref_metadata_2025 huggingface dataset:
Compact Uwb Multilayer 3 Db Directional Coupler Design And Analysis on Coupler Performances
Authors: Abang Zaidel Dyg Norkhairunnisa , Abdul Rahim Sharul Kamal , Seman Norhudah , Adam Ashraf Abdulrahman , Rahman Tharek Abdul , Hall Peter S.
Published: June 2013

An extended works of a diamond shaped 3 dB coupler design that is operating in ultra‐wideband frequency range is presented in this article. The proposed design is accomplished by using multilayer technology in which the structure is formed by three layers of conductors and interleaved by a layer of substrate between each one of the conductor layer. The proposed designed coupler simulation result shows that the design exhibits a coupling of 3 dB return loss and isolation better than 22 and 21 dB, respectively. Whereas, the phase difference performance is in the range of 90° ± 2° over the designated band. The coupler is fabricated and measured. Analysis studies on the parametric value are presented and discussed to observe the effect of the dimension of the patch to the performance of the coupler. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:2214–2219, 2013
A Novel Modeling of Millimeter‐Wave Al0.27Ga0.73N/AlN/GaN Hemt Based on Artificial Neural Network
Authors: Cheng Zhi‐qun , Wang Xi , Zhang Qi‐qun
Published: June 2013

An artificial neural network (ANN) was used for modeling millimeter‐wave Al0.27Ga0.73N/AlN/GaN high electron mobility transistor (HEMT) with multi‐biases in this article. Millimeter‐wave Al0.27Ga0.73N/AlN/GaN HEMT with gate width of 2 × 75 µm and gate length of 0.3 µm was designed and fabricated at first, and then its performance was measured for modeling. NeuroModelerPlus_V2.1E software was trained to learn the input‐output relationship from the data about DC and AC performances of proposed device. ANN DC model and AC model were set up and embedded in software of ADS together to form a model of millimeter‐wave Al0.27Ga0.73N/AlN/GaN HEMT, which can be used in circuit design. The results of the simulation of the model showed that it corresponded with the measurement results. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:2124–2127, 2013
Discrete Green's Function Approach for The Analysis of A Dual Band‐Notched Uwb Antenna
Authors: Mirhadi Salma , Soleimani Mohammad , Abdolali Ali
Published: June 2013

A novel UWB monopole antenna with trident feeding and dual band‐notched characteristics is proposed. The antenna consists of two bottom corner notches for improvement of impedance matching and two U‐shaped slots for rejection of WLAN and WiMAX bands. Discrete Green's function approach has been utilized to numerically achieve time‐domain current distribution on the antenna. A good agreement between simulation and experimental results is observed. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:2168–2174, 2013
Synthesis of novel hyperbranched polymers featuring oxazoline linear units and their application in fast‐drying solvent‐borne coating formulations
Authors: Cheng Ge , Greenland Barnaby W. , Lampard Chris , Williams Neal , Bahra Malkit S. , Hayes Wayne
Published: June 2013

Novel acid‐terminated hyperbranched polymers (HBPs) containing adipic acid and oxazoline monomers derived from oleic and linoleic acid have been synthesized via a bulk polymerization procedure. Branching was achieved as a consequence of an acid‐catalyzed opening of the oxazoline ring to produce a trifunctional monomer in situ which delivered branching levels of >45% as determined by 1H and 13C NMR spectroscopy. The HBPs were soluble in common solvents, such as CHCl3, acetone, tetrahydrofuran, dimethylformamide, and dimethyl sulfoxide and were further functionalized by addition of citronellol to afford white‐spirit soluble materials that could be used in coating formulations. During end group modification, a reduction in branching levels of the HBPs (down to 12–24%) was observed, predominantly on account of oxazoline ring reformation and trans‐esterification processes under the reaction conditions used. In comparison to commercial alkyd resin paint coatings, formulations of the citronellol‐functionalized hyperbranched materials blended with a commercial alkyd resin exhibited dramatic decreases of the blend viscosity when the HBP content was increased. The curing characteristics of the HBP/alkyd blend formulations were studied by dynamic mechanical analysis which revealed that the new coatings cured more quickly and produced tougher materials than otherwise identical coatings prepared from only the commercial alkyd resins. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013, 51, 3964–3974
Selective peptide inhibitors of bifunctional thymidylate synthase‐dihydrofolate reductase from Toxoplasma gondii provide insights into domain–domain communication and allosteric regulation
Authors: J. Landau Mark , Sharma Hitesh , Anderson Karen S.
Published: June 2013

The bifunctional enzyme thymidylate synthase–dihydrofolate reductase (TS–DHFR) plays an essential role in DNA synthesis and is unique to several species of pathogenic protozoans, including the parasite Toxoplasma gondii. Infection by T. gondii causes the prevalent disease toxoplasmosis, for which TS–DHFR is a major therapeutic target. Here, we design peptides that target the dimer interface between the TS domains of bifunctional T. gondii TS–DHFR by mimicking β‐strands at the interface, revealing a previously unknown allosteric target. The current study shows that these β‐strand mimetic peptides bind to the apo‐enzyme in a species‐selective manner to inhibit both the TS and distal DHFR. Fluorescence spectroscopy was used to monitor conformational switching of the TS domain and demonstrate that these peptides induce a conformational change in the enzyme. Using structure‐guided mutagenesis, nonconserved residues in the linker between TS and DHFR were identified that play a key role in domain–domain communication and in peptide inhibition of the DHFR domain. These studies validate allosteric inhibition of apo‐TS, specifically at the TS–TS interface, as a potential target for novel, species‐specific therapeutics for treating T. gondii parasitic infections and overcoming drug resistance.
Extension of metal oxide laser ionization mass spectrometry to analytes with varied chemical functionalities
Authors: McAlpin Casey R. , Voorhees Kent J.
Published: June 2013

RATIONALE

Applications of metal oxide laser ionization mass spectrometry (MOLI MS) have been limited to compounds that provide protons for ionization upon adsorption to a metal oxide surface. The addition of a small molecule, which can act as a proton source and extend MOLI MS applications to a wider variety of analytes, was investigated.

METHODS

Mass spectrometric measurements were made with a PerSeptive Biosystems Voyager DE‐STR MALDI mass spectrometer, using NiO‐based MOLI to generate ions. NiO was pretreated in this study with a number of small molecules to act as proton sources during ionization. Peptides, monosaccharides, and a crude oil sample were analyzed with pretreated and untreated NiO.

RESULTS

Candidate small molecule proton donors were evaluated based on their effect on signal‐to‐noise ratio and peak intensity for tristearin. The best performing proton source was used for subsequent analyses. The analysis of monosaccharides, peptides and compounds in heavy crude oil was enhanced by the use of proton source treated NiO for MOLI MS. Proton/cation exchange following ionization was observed.

CONCLUSIONS

Addition of a proton source to NiO enhanced the MOLI MS response for peptides, carbohydrates, and compounds in a crude oil sample. Efficient ionization of these samples effectively extended applications of MOLI MS beyond lipid analytes containing esters. Copyright © 2013 John Wiley & Sons, Ltd.
On the Crystal Chemistry of Alkaline Earth‐ and Rare Earth‐Oxocobaltates
Authors: Müller‐Buschbaum Hanskarl
Published: June 2013

A review on the crystal chemistry of oxocobaltates of alkaline earth and rare earth metals is presented according to the formula of the compounds, based on increasing metal and oxygen content. The well‐known structures of perowskites and K2NiF4‐type compounds and their higher homologues have been ignored and cross‐referred to older publications. Cobalt shows mainly the oxidation states Co2+ and Co3+. In many cases it exhibits integer valences like Co2.28+, Co2.5+, Co2.54+, Co2.8+, Co3.5, and Co3.6+, referred in the ICSD database. The dominant coordination polyhedra are CoO4‐tetrahedra and CoO6‐oktahedra. In two cases a trigonal prismatic CoO6‐coordination is observed. Composition, crystal structure, and oxidation state of cobalt often depend on the preparation conditions. In contrast to the alkaline oxides, the alkaline earth and rare earth oxides used for preparations are less reactive. Therefore the necessary reaction temperatures are much higher. In these cases single crystals for x‐ray investigation were prepared by plasma‐burner and CO2‐LASER techniques.
Updated global analysis of Higgs couplings
Authors: Ellis John , You Tevong
Published: June 2013

Abstract

There are many indirect and direct experimental indications that the new particle H discovered by the ATLAS and CMS Collaborations has spin zero and (mostly) positive parity, and that its couplings to other particles are correlated with their masses. To a high degree of confidence, it is a Higgs boson, and here we examine the extent to which its couplings resemble those of the single Higgs boson of the Standard Model. Our global analysis of its couplings to fermions and massive bosons determines that they have the same relative sign as in the Standard Model. We also show directly that these couplings are highly consistent with a dependence on particle masses that is linear to within a few %, and scaled by the conventional electroweak symmetry-breaking scale to within 10%. We also give constraints on loop-induced couplings, on the total Higgs decay width, and on possible invisible decays of the Higgs boson under various assumptions.
Complex between α-bungarotoxin and an α7 nicotinic receptor ligand-binding domain chimaera
Authors: Huang Sun , Li Shu-Xing , Bren Nina , Cheng Kevin , Gomoto Ryan , Chen Lin , Sine Steven M.
Published: June 2013

To identify high-affinity interactions between long-chain α-neurotoxins and nicotinic receptors, we determined the crystal structure of the complex between α-btx (α-bungarotoxin) and a pentameric ligand-binding domain constructed from the human α7 AChR (acetylcholine receptor) and AChBP (acetylcholine-binding protein). The complex buries ~2000 Å2 (1 Å=0.1 nm) of surface area, within which Arg36 and Phe32 from finger II of α-btx form a π-cation stack that aligns edge-to-face with the conserved Tyr184 from loop-C of α7, while Asp30 of α-btx forms a hydrogen bond with the hydroxy group of Tyr184. These inter-residue interactions diverge from those in a 4.2 Å structure of α-ctx (α-cobratoxin) bound to AChBP, but are similar to those in a 1.94 Å structure of α-btx bound to the monomeric α1 extracellular domain, although compared with the monomer-bound complex, the α-btx backbone exhibits a large shift relative to the protein surface. Mutational analyses show that replacing Tyr184 with a threonine residue abolishes high-affinity α-btx binding, whereas replacing with a phenylalanine residue maintains high affinity. Comparison of the α-btx complex with that coupled to the agonist epibatidine reveals structural rearrangements within the binding pocket and throughout each subunit. The overall findings highlight structural principles by which α-neurotoxins interact with nicotinic receptors.
Scaling of maximum velocity, body force, and power consumption of dielectric barrier discharge plasma actuators via particle image velocimetry
Authors: Murphy J. P. , Kriegseis J. , Lavoie P.
Published: June 2013

This study presents Particle Image Velocimetry (PIV) measurements of the induced flow characteristics generated by single dielectric barrier discharge (DBD) actuators in quiescent conditions. The primary aim is to establish accurate empirical trends for model development on both the maximum induced velocity and body force with voltage and consumed power. The results reveal a power law variation for the maximum velocity at low voltages which is followed by an asymptotic behavior. In contrast, the body force is characterized by two power law regions. The power law exponent is shown to be a function of the dielectric thickness, frequency and dielectric constant. Reducing the former or increasing the latter two result in a higher coefficient and lower voltage at which the trend changes. The onset of the second region occurs at a Re ∼ 100 (based on the maximum velocity, um, and corresponding half height, y1/2) and is characterized by a velocity profile which no longer agrees with the laminar profile of Glauert whilst moving increasingly towards the turbulent case. Phase locked PIV measurements show that as the voltage increases the peak momentum transfer shifts from the middle of the AC cycle to the latter end of the forward stroke. Lissajous plots of umϕ against the corresponding x location and plasma length Δx demonstrate that the peak momentum transfer remains relatively fixed in space as the voltage and plasma length increase.
Current-voltage characteristics of low-resistance tunnel structures ferromagnet-insulator-superconductor Co2CrAl–I–Pb
Authors: Rudenko E. M. , Shlapak Yu. V. , Korotash I. V. , Dyakin M. V.
Published: June 2013

A physical model of tunneling processes leading to a nonequilibrium superconducting state in ferromagnet-superconductor junctions is proposed and confirmed experimentally. The model is based on the analysis of experimental current-voltage characteristics and the determination of junction voltage dependences of the energy gap, the effective chemical potential and the effective temperature of quasiparticles in the modified energy distribution of quasiparticles as well as on taking into account the change in the density of electron states due to destruction of the Cooper pairs, caused by the proximity effect.
Nonlinear dynamics and solitons of a chain with spherical magnetic nanoparticles
Authors: Dzyan S. A. , Ivanov B. A.
Published: June 2013

Free-moving magnetic particles in the presence of a magnetic dipole interaction between their magnetic moments can be arranged in dense phases, the simplest of which is a linear chain. The nonlinear dynamics associated with the displacement of particles in such a chain is studied with taking into account the magnetic dipole interaction and the molecular Van der Waals interaction. It is shown that this chain has interesting properties of a nonlinear dynamical system. For it one can construct exact solutions which describe propagating nonlinear waves of a constant amplitude with a wavelength comparable with a distance between particles, as well as soliton solutions. A role of the nonlinearity of oscillations turns out to be very important for a problem of stability of a chain with respect to the transition to a dense three-dimensional cluster.
The mechanics of 2D crystals: A change from the atomic-lattice description to equations of the elasticity theory
Authors: Natsik V. D. , Smirnov S. N.
Published: June 2013

A two-dimensional (2D) crystal formed by a system of identical atoms with a pair centrosymmetric interaction between them is considered. It is assumed that in the initial state of equilibrium atoms occupy sites of a flat translation-symmetrical mesh, and the deformed state appears as a result of their displacements in the crystal plane (longitudinal deformations) and in the direction perpendicular to it (flexural deformations). It is shown that in the continuum description an infinitely thin anisotropic film with a finite mass density, which is capable of elastic longitudinal and flexural deformations, corresponds to this crystal. In the framework of classical mechanics we derive the basic relations and equations for atomic displacements and corresponding to them equations of the elasticity theory, describing both modes of deformation of a 2D crystal in the linear approximation as well as with taking into account anharmonicities. The explicit expressions which relates moduli of linear and nonlinear elasticity of the crystal with the potential of interatomic interaction and geometrical characteristics of the flat crystal lattice are obtained.
Relaxation phenomena in cryogenic electrolytes
Authors: Shikin V. , Chikina I. , Nazin S.
Published: June 2013

Proposed is a scenario for the development of observed relaxation phenomena in a cryogenic electrolyte with the structure of “liquid hydrogen + injected ions.” Ions of one sign are generated in the bulk of liquid hydrogen in the presence of external field E⊥ by a stationary radioactive source of ± ions at the bottom of a vessel. After accumulation near the free surface of the liquid with a finite density ns the ions can break its stability producing a pulse of ion current to the collector located above the liquid surface. The outlined process is periodically repeated. Its period contains information on the ion mobility and, which is most interesting, on dissociation (association) processes occurring in a system of charged particles placed in an external field. The cryogenic problem is a good model for dissociation in the presence of external field occurring in normal electrolytes without any external ion sources.
Functional derivatives of meta-generalized gradient approximation (meta-GGA) type exchange-correlation density functionals
Authors: Zahariev F. , Leang S. S. , Gordon Mark S.
Published: June 2013

Meta-generalized gradient approximation (meta-GGA) exchange-correlation density functionals depend on the Kohn-Sham (KS) orbitals through the kinetic energy density. The KS orbitals in turn depend functionally on the electron density. However, the functional dependence of the KS orbitals is indirect, i.e., not given by an explicit expression, and the computation of analytic functional derivatives of meta-GGA functionals with respect to the density imposes a challenge. The practical solution used in many computer implementations of meta-GGA density functionals for ground-state calculations is abstracted and generalized to a class of density functionals that is broader than meta-GGAs and to any order of functional differentiation. Importantly, the TDDFT working equations for meta-GGA density functionals are presented here for the first time, together with the technical details of their computer implementation. The analysis presented here also uncovers the implicit assumptions in the practical solution to computing functional derivatives of meta-GGA density functionals. The connection between the approximation that is invoked in taking functional derivatives of density functionals, the non-uniqueness with respect to the KS orbitals, and the non-locality of the resultant potential is also discussed.
Quadrupole phases and phase transitions in uniaxial magnets with tensor interactions
Authors: Shapovalov I. P.
Published: June 2013

Uniaxial magnets with spin one, single-ion anisotropy, and anisotropic biquadratic exchange interaction are investigated in the absence of magnetic field. Possible types of quadrupole ordering in the system are discussed for the case in which the anisotropy of biquadratic exchange interaction has the most general form compatible with the axial symmetry. Besides the two phases with the stationary planes of quadrupole ordering (QOZ and QOX phases), there may appear a phase (QO< phase) in which the orientation of the quadrupolar-ordering plane changes continuously as the Hamiltonian parameters are varied. For the QOX phase, two branches of spin excitations have been found, one of which includes the Goldstone mode. The QO< phase boundary with the other two quadrupolar phases at finite temperatures has been determined, the expression for the QO<–QOZ phase boundary has been derived analytically.
Improvement of range precision in laser detection and ranging system by using two Geiger mode avalanche photodiodes
Authors: Kim Tae Hoon , Kong Hong Jin , Jo Sung Eun , Jeon Byoung Goo , Oh Min Seok , Heo Ayoung , Park Dong Jo
Published: June 2013

In this paper, the improvement of range precision in a laser detection and ranging (LADAR) system by using two Geiger mode avalanche photodiodes (GmAPDs) is described. The LADAR system is implemented by using two GmAPDs with a beam splitter and applying comparative process to their ends. Then, the timing circuit receives the electrical signals only if each GmAPDs generates electrical signals simultaneously. Though this system decreases the energy of a laser-return pulse scattered from the target, it is effective in reducing the range precision. The experimental results showed that the average value of standard deviation of time of flights was improved from 61 mm to 37 mm when the pulse energy is 0.6 μJ. When the time bin width is 0.5 ns, the single-shot precision error of the LADAR system was also improved from 280 mm to 67 mm.
In-line interferometric femtosecond stimulated Raman scattering spectroscopy
Authors: Dobner Sven , Groß Petra , Fallnich Carsten
Published: June 2013

We present in-line interferometric femtosecond stimulated Raman scattering (II-FSRS), a new method to measure the spectral Raman intensity and phase over a broad spectral range, potentially in a single shot. An analytic model is developed, that excellently reproduces the measured spectra. Additionally, the performance of II-FSRS is directly compared in experiments to two established techniques, namely femtosecond stimulated Raman scattering and femtosecond Raman induced Kerr-effect spectroscopy.
Spatial heterogeneous distribution of SiOx → SiOx±1 reactions in silica liquid
Authors: Hung P. K. , Ha N. T. T. , Lan M. T. , Hong N. V.
Published: June 2013

We have numerically studied the diffusion mechanism in silica liquid following an approach where the diffusion rate is evaluated via the SiOx → SiOx±1 reaction rate υreact and the mean square displacement of particles dreact as a reaction happens. Five models at pressure up to 25 GPa and at a temperature of 3000 K have been constructed by molecular dynamic simulation. When applying pressure to the liquid, υreact increases monotonously because the Si–O bond becomes weaker with pressure. Meanwhile dreact attains a maximum near the point of 10 GPa despite the particles move in a significantly smaller volume. Furthermore, the SiOx → SiOx±1 reactions are spatially heterogeneously distributed in the liquid. Upon low pressure, most reactions happen with a small number of Si particles. This reaction localization causes the diffusion anomaly and dynamics heterogeneity in the liquid. With increasing pressure the diffusion mechanism changes from the heterogeneous spatial distribution of reactions to homogeneous one. The simulation also reveals two distinguished regions with quite different coordination environments where the reaction rate significantly differs from each other. These sets of Si particles migrate in space over time and form regions with so-called “fast” and “slow” Si particles. The result obtained here indicates the coexistence of low- and high-density regions, and supports the concept of polymorphism in silica liquid.
Correlation of doping, structure, and carrier dynamics in a single GaN nanorod
Authors: Zhou Xiang , Lu Ming-Yen , Lu Yu-Jung , Gwo Shangjr , Gradečak Silvija
Published: June 2013

We report the nanoscale optical investigation of a single GaN p-n junction nanorod by cathodoluminescence (CL) in a scanning transmission electron microscope. CL emission characteristic of dopant-related transitions was correlated to doping and structural defect in the nanorod, and used to determine p-n junction position and minority carrier diffusion lengths of 650 nm and 165 nm for electrons and holes, respectively. Temperature-dependent CL study reveals an activation energy of 19 meV for non-radiative recombination in Mg-doped GaN nanorods. These results directly correlate doping, structure, carrier dynamics, and optical properties of GaN nanostructure, and provide insights for device design and fabrication.
Donor-acceptor pair luminescence in B and P compensated Si co-doped with Ga
Authors: Tajima Michio , Tanaka Koji , Forster Maxime , Toyota Hiroyuki , Ogura Atsushi
Published: June 2013

The electrical activity of Ga impurities in a high concentration range in B and P highly compensated Si co-doped with Ga for photovoltaic applications has been investigated through the analysis of donor-acceptor pair luminescence. We have identified the fine structure due to the pair luminescence between P-donors and Ga-acceptors based on a comparison with a theoretical spectrum using their generally accepted ionization energies in low concentration ranges in uncompensated Si. The fine structure showed no dependence on dopant concentrations in the P and Ga concentration ranges from 7 × 1016 to 4 × 1017 cm−3 and from 5 × 1016 to 3 × 1017 cm−3, respectively, which leads us to suggest that both P and Ga impurities act as isolated donors and acceptors without noticeable reduction of ionization energies due to high doping.
Note: Photodissociation of CH3COCN at 308 nm by time-resolved Fourier-transform infrared emission spectroscopy: Is CO a primary or secondary product?
Authors: Tsai Po-Yu , Lin King-Chuen
Published: June 2013

This Note aims to clarify the source of CO in photodissociation of acetyl cyanide (CH3COCN) at 308 nm. From the theoretical aspects, a new pathway via isomerization transition state (TS) at 391 ± 8 kJ/mol is found leading to the CO + CH3NC products. An amount of 60% reactant molecules at 300 K is estimated to successfully surpass the average TS barrier lying above the excitation energy by 3.5 kJ/mol. Further, a prior distribution method is conducted to characterize the vibrational energy distribution of CO on a statistical basis. The pathway to CH3NC + CO yields a vibrational branching ratio (v = 0:v = 1:v = 2:v = 3∼0.63:0.25:0.093:0.032) in excellent agreement with the observation (0.62:0.25:0.09:0.05).
Characterization of the thermal properties for Si-implanted Sb2Te3 phase change material
Authors: Zhang Zhonghua , Song Sannian , Song Zhitang , Cheng Yan , Gu Yifeng , Chen Bomy
Published: June 2013

The microstructure and thermal properties of Si-implanted Sb2Te3 were investigated. Crystalline Si-implanted Sb2Te3 film with relatively uniform composition depth profile was fabricated, which consists of Si4−x (0 < x < 1) ions and crystalline Sb2Te3. No separated Te phase was found. The crystallization activation energies of crystallization increase with Si dose from 5 × 1015 to 2.16 × 1016 Si-ions/cm2. The crystallization temperatures of the films are 149, 168, and 174 °C with 5 × 1015, 1 × 1016, and 2.16 × 1016 Si-ions/cm2 ion implantation, respectively. Furthermore, the Sb2Te3 film implanted with the dose of 1 × 1016 Si-ions/cm2 can maintain the data for 10 yr at 85 °C, which is comparable to Ge2Sb2Te5. The results indicate that the Si-implanted Sb2Te3 is a promising candidate for phase change memory application.
The microstructure, electronic, and magnetic characterization of highly ordered Co2MnSi thin films deposited on MgO substrate
Authors: Yang F. J. , Chen X. Q.
Published: June 2013

Co2MnSi thin films are usually deposited on Cr-buffered MgO substrate. In this work, Co2MnSi thin films were deposited directly on MgO substrate and annealed at 350 °C to 650 °C to investigate the evolution of microstructure, electronic, and magnetic properties. Due to nearly perfect B2-ordering and very good L21-ordering, the Ms increases to 1029 emu/cc and Hc decreases to 27 Oe, respectively, after annealing at 650 °C. The large residual resistance ratio (RRR = 2.40) and small magnetic damping constant (α = 0.0039) further demonstrates that nearly perfect B2-ordering, good L21 ordering, and nearly perfect film quality have been achieved.
Evaluation of Methicillin-Resistant Staphylococcus aureus Skin and Soft-Tissue Infection Prevention Strategies at a Military Training Center
Authors: Morrison Stephanie M. , Blaesing Carl R. , Millar Eugene V. , Chukwuma Uzo , Schlett Carey D. , Wilkins Kenneth J. , Tribble David R. , Ellis Michael W.
Published: June 2013

Military trainees are at high risk for skin and soft-tissue infections (SSTIs), especially those caused by methicillin-resistant Staphylococcus aureus (MRSA). A multicomponent hygiene-based SSTI prevention strategy was implemented at a military training center. After implementation, we observed 30% and 64% reductions in overall and MRSA-associated SSTI rates, respectively.
GeneScissors: a comprehensive approach to detecting and correcting spurious transcriptome inference owing to RNA-seq reads misalignment
Authors: Zhang Zhaojun , Huang Shunping , Wang Jack , Zhang Xiang , Pardo Manuel de Villena Fernando , McMillan Leonard , Wang Wei
Published: June 2013

Motivation: RNA-seq techniques provide an unparalleled means for exploring a transcriptome with deep coverage and base pair level resolution. Various analysis tools have been developed to align and assemble RNA-seq data, such as the widely used TopHat/Cufflinks pipeline. A common observation is that a sizable fraction of the fragments/reads align to multiple locations of the genome. These multiple alignments pose substantial challenges to existing RNA-seq analysis tools. Inappropriate treatment may result in reporting spurious expressed genes (false positives) and missing the real expressed genes (false negatives). Such errors impact the subsequent analysis, such as differential expression analysis. In our study, we observe that ∼3.5% of transcripts reported by TopHat/Cufflinks pipeline correspond to annotated nonfunctional pseudogenes. Moreover, ∼10.0% of reported transcripts are not annotated in the Ensembl database. These genes could be either novel expressed genes or false discoveries.

Results: We examine the underlying genomic features that lead to multiple alignments and investigate how they generate systematic errors in RNA-seq analysis. We develop a general tool, GeneScissors, which exploits machine learning techniques guided by biological knowledge to detect and correct spurious transcriptome inference by existing RNA-seq analysis methods. In our simulated study, GeneScissors can predict spurious transcriptome calls owing to misalignment with an accuracy close to 90%. It provides substantial improvement over the widely used TopHat/Cufflinks or MapSplice/Cufflinks pipelines in both precision and F-measurement. On real data, GeneScissors reports 53.6% less pseudogenes and 0.97% more expressed and annotated transcripts, when compared with the TopHat/Cufflinks pipeline. In addition, among the 10.0% unannotated transcripts reported by TopHat/Cufflinks, GeneScissors finds that >16.3% of them are false positives.

Availability: The software can be downloaded at http://csbio.unc.edu/genescissors/

Contact:  weiwang@cs.ucla.edu

Supplementary information:  Supplementary data are available at Bioinformatics online.
Abnormal protein turnover and anabolic resistance to exercise in sarcopenic obesity
Authors: Nilsson Mats I. , Dobson Justin P. , Greene Nicholas P. , Wiggs Michael P. , Shimkus Kevin L. , Wudeck Elyse V. , Davis Amanda R. , Laureano Marissa L. , Fluckey James D.
Published: June 2013

Obesity may impair protein synthesis rates and cause anabolic resistance to growth factors, hormones, and exercise, ultimately affecting skeletal muscle mass and function. To better understand muscle wasting and anabolic resistance with obesity, we assessed protein 24‐h fractional synthesis rates (24‐h FSRs) in selected hind‐limb muscles of sedentary and resistance‐exercised lean and obese Zucker rats. Despite atrophied hind‐limb muscles (–28% vs. lean rats), 24‐h FSRs of mixed proteins were significantly higher in quadriceps (+18%) and red or white gastrocnemius (+22 or +38%, respectively) of obese animals when compared to lean littermates. Basal synthesis rates of myofibrillar (+8%) and mitochondrial proteins (–1%) in quadriceps were not different between phenotypes, while manufacture of cytosolic proteins (+12%) was moderately elevated in obese cohorts. Western blot analyses revealed a robust activation of p70S6k (+178%) and a lower expression of the endogenous mTOR inhibitor DEPTOR (–28%) in obese rats, collectively suggesting that there is an obesity‐induced increase in net protein turnover favoring degradation. Lastly, the protein synthetic response to exercise of mixed (–7%), myofibrillar (+6%), and cytosolic (+7%) quadriceps subfractions was blunted compared to the lean phenotype (+34, +40, and +17%, respectively), indicating a muscle‐ and subfraction‐specific desensitization to the anabolic stimulus of exercise in obese animals.—Nilsson, M. I., Dobson, J. P., Greene, N. P., Wiggs, M. P., Shimkus, K. L., Wudeck, E. V., Davis, A. R., Laureano, M. L., Fluckey, J. D., Abnormal protein turnover and anabolic resistance to exercise in sarcopenic obesity. FASEB J. 27, 3905–3916 (2013). www.fasebj.org
Evolutionary dynamics of bovine coronaviruses: natural selection pattern of the spike gene implies adaptive evolution of the strains
Authors: Bidokhti Mehdi R. M. , Tråvén Madeleine , Krishna Neel K. , Munir Muhammad , Belák Sándor , Alenius Stefan , Cortey Martí
Published: June 2013

Coronaviruses demonstrate great potential for interspecies transmission, including zoonotic outbreaks. Although bovine coronavirus (BCoV) strains are frequently circulating in cattle farms worldwide, causing both enteric and respiratory disease, little is known about their genomic evolution. We sequenced and analysed the full-length spike (S) protein gene of 33 BCoV strains from dairy and feedlot farms collected during outbreaks that occurred from 2002 to 2010 in Sweden and Denmark. Amino acid identities were >97 % for the BCoV strains analysed in this work. These strains formed a clade together with Italian BCoV strains and were highly similar to human enteric coronavirus HECV-4408/US/94. A high similarity was observed between BCoV, canine respiratory coronavirus (CRCoV) and human coronavirus OC43 (HCoV-OC43). Molecular clock analysis of the S gene sequences estimated BCoV and CRCoV diverged from a common ancestor in 1951, while the time of divergence from a common ancestor of BCoV and HCoV-OC43 was estimated to be 1899. BCoV strains showed the lowest similarity to equine coronavirus, placing the date of divergence at the end of the eighteenth century. Two strongly positive selection sites were detected along the receptor-binding subunit of the S protein gene: spanning amino acid residues 109–131 and 495–527. By contrast, the fusion subunit was observed to be under negative selection. The selection pattern along the S glycoprotein implies adaptive evolution of BCoVs, suggesting a successful mechanism for BCoV to continuously circulate among cattle and other ruminants without disappearance.
Software for Constructing and Verifying Pedigrees within Large Genealogies and an Application to the Old Order Amish of Lancaster County
Authors: Agarwala Richa , Biesecker Leslie G. , Hopkins Katherine A. , Francomano Clair A. , Schaffer Alejandro A.
Published: June 2013

This paper describes PedHunter, a software package that facilitates creation and verification of pedigrees within large genealogies. A frequent problem in medical genetics is to connect distant relatives with a pedigree. PedHunter uses methods from graph theory to solve two versions of the pedigree connection problem for genealogies as well as other pedigree analysis problems. The pedigrees are produced by PedHunter as files in LINKAGE format ready for linkage analysis. PedHunter uses a relational database of genealogy data, with tables in specified format, for all calculations. The functionality and utility ofPedHunter are illustrated by examples using the Amish Genealogy Database (AGDB), which was created for the Old Order Amish community of Lancaster County, Pennsylvania.
Graph theoretic approach for analysing the readiness of an organisation for adapting lean thinking
Authors: Gurumurthy Anand , Mazumdar Prasoon , Muthusubramanian Sowmiya
Published: June 2013

Purpose

A literature review revealed that in recent times, many companies have attempted organization‐wide change management through the philosophy and principles of Lean Thinking (LT). Although some organizations have transformed and reaped significant benefits in this endeavour, many organizations have failed in this attempt. One of the reasons can be attributed to the fact that not many organizations are attempting to “assess the organizational readiness” before implementing/adapting LT. This paper aims to address this issue.

Design/methodology/approach

Hence in this paper, an attempt has made to address this problem by presenting a hypothetical case study of an Indian organization to comprehensively assess organizational readiness of the case organisation using a graph theoretic approach (GTA), which has the ability to integrate and model multiple inter‐related factors.

Findings

From the obtained results, it was found that the case organization is not fully ready to embrace LT. It needs to work on different factors under the categories of suppliers, customers, etc. in addition to employees, organisation and top management for smooth and successful adaptation.

Originality/value

According to the authors' knowledge, no paper exists either in the literature of organizational analysis or in the field of LT literature that demonstrates the application of GTA, specifically for assessing the readiness of an organization in adapting LT. Furthermore, various factors which need to be considered were identified apart from modelling them by incorporating the relationship/dependency that exists between these factors, which is unique.
SOA implementation critical success factors in healthcare
Authors: Koumaditis Konstantinos , Themistocleous Marinos , Rupino Da Cunha Paulo
Published: June 2013

Purpose

Service oriented architecture (SOA) is increasingly adopted by many sectors, including healthcare. Due to the nature of healthcare systems, there is a need to increase SOA adoption success rates as the non‐integrated nature of healthcare systems is responsible for medical errors that cause the loss of tens of thousands of patients per year. Although numerous factors affect SOA success, these have not been explored and analysed yet, especially in the area of healthcare. This highlights a literature void and thus the purpose of this paper is to identify critical success factors (CSFs) influencing SOA implementation in healthcare.

Design/methodology/approach

The authors critically review the literature and identify individual factors that may form CSFs for SOA implementation in healthcare. In doing so, they synthesise and propose a conceptual model of SOA CSFs in healthcare. The conceptual model is tested in the practical arena using a qualitative research methodology that is based on a case study strategy.

Findings

The empirical findings verify the proposed model and reveal that an additional SOA CSF in healthcare does exist. It is also revealed that the proposed model helped the case organization to successfully implement an SOA solution.

Research limitations/implications

The implications that derive from this article are important for both theory and practice. At a practical level, the paper delivers a model that can be used as a decision‐making tool by professionals when they implement SOA solutions in healthcare. At a theoretical level, the proposed model extends the body of knowledge on this area and opens new avenues for research. From another point of view, it is suggested that further research is required on this area as the proposed conceptual model was tested only through a single case study. Thus, multiple case studies or other types of research strategies should be used to better test the proposed model.

Originality/value

This work is original and focuses on CSFs related to SOA implementations in healthcare organizations. The work can be considered as novel as it identifies and classifies SOA CSFs for solutions that have been developed in the area of healthcare.
Internet as an information source and social distance: any relationship?
Authors: S. Yilmaz Semih , D.A. Tasci Asli
Published: June 2013

Purpose

– Findings of previous research imply that virtual contact with other social groups, such as the internet, may have an impact on sociocultural dimensions such as social distance; however, there is a lack of empirical evidence supporting this implication. To fill this void in the literature, the purpose of this paper is to explore the relationship between social distance and the internet as an information source.

Design/methodology/approach

– A self-administered survey was conducted on tourists from several different European countries, through random sampling, in select popular tourist destinations of Turkey.

Findings

– A direct relationship between the use of the internet as an information source about the host community and social distance was not revealed within the scope of this study.

Originality/value

– There is limited research on the relationship between Internet and several sociocultural aspects in tourism. This study investigates the relationship between social distance and internet empirically.
The new customer-facing technology: mobile and the constantly-connected consumer
Authors: Anne Coussement Martha , J. Teague Thomas
Published: June 2013

Purpose

– The purpose of this paper is to argue that the use of technology by the “always connected” guest has changed the dynamics of the relationship between the hospitality entity and customer. Today's mobile customers have begun to create their own customized value with an organization. This transformation has caused a paradigm shift in a relationship once built on static, episodic periods of communication.

Design/methodology/approach

– This paper conceptualizes a framework to support the claim of technological change begun with the internet and migrating to the present use of mobile technology. This change has fundamentally altered both business and leisure lives of travellers. The design of the article pivots around customer-facing technology as the principal engagement factor in developing a new model for decision making by industry.

Findings

– Customers now access information as they need it; they are no longer tethered to a desktop device. This freedom has allowed the consumer to create value when and where he/she chooses. The duration of time for potential interaction has expanded, as the company can push information more frequently to their customers; however, the guest can still choose how often, when and where to pull the details. The customer has become his/her own “host” with the solutions provided by mobile technology.

Research limitations/implications

– With the accelerating adoption of customer-facing devices, the issues of privacy and security have gained greater importance. Another research extension of this paper includes the impact of customer-facing technology on the guest life cycle and the impact of location-based services and “Near Field” communications on the customer experience.

Practical implications

– Customers want their travel experience to be a seamless one; hospitality companies will need to begin a new customer-facing dialogue with their visitors. This industry can benefit from understanding the customer's greater power by comprehending the timing and duration of messages based on this mobile environment.

Originality/value

– Mobile technology has allowed the untethered, always available consumer, to have control over his experience and the ability to customize his experience. This paper demonstrates that as the hospitality industry has moved away from management-facing technology to the new customer-facing technology, this paradigm shift offers the industry enormous opportunity to continue its development of newer and better mobile technologies.
Summary of selected sessions from “The SEC Speaks in 2013”
Authors: Rubin Brian L. , Brun Carmen L. , Stewart Faulkner Jaliya , Freedman Michael K. , Lentz Kurt , Yoon Jae C.
Published: June 2013

Purpose

The purpose of this paper us to summarize the remarks of the Commissioners and participants in several panel sessions and workshops during the 2013 annual “SEC Speaks” conference held by the Practising Law Institute in cooperation with the US Securities and Exchange Commission, discussing the SEC's accomplishments in 2012 and its agenda for 2013.

Design/methodology/approach

The paper summarizes remarks by Chairman Walter and Commissioners Aguilar, Paredes, and Gallagher; provides highlights from panel sessions and workshops concerning the Division of Corporation Finance, the Division of Trading and Markets, the Division of Enforcement, the Division of Investment Management, the Office of Compliance Inspections and Examinations as well as highlights from the panel sessions relating to Accounting, Risk, Strategy and Financial Innovation. Judicial and Legislative Developments, and Ethics.

Findings

The summaries provide an overview of the SEC's most important current rulemaking, projects and policy priorities.

Originality/value

The paper presents current SEC issues and developments addressed by experienced SEC lawyers.
The proposed EU Financial Transaction Tax
Authors: Macleod Neil , Gaut Robert
Published: June 2013

Purpose

The purpose of this paper is to explain the background, scope, applications, criticisms, and UK legal challenge of the European Union's Financial Transaction Tax (FTT).

Design/methodology/approach

The paper explains the “enhanced cooperation” from the 11 member states implementing the FTT; revenue expected from the FTT; financial transactions, instruments, and institutions to which the FTT applies; territorial application of the FTT; chargeability and payment of the FTT; an anti‐abuse rule; a proposed implementation timetable; criticisms of the FTT; and the UK's legal challenge.

Findings

The UK is concerned that the FTT will have an adverse impact on its financial services sector and therefore has launched a legal challenge, increasing the likelihood that the tax will be changed before it is due to apply at the beginning of 2014.

Originality/value

The paper provides practical guidance by expert financial services and tax lawyers.
Foodscapes and wellbeing in the workplace: a university setting
Authors: Symonds C.R. , Martins A.C. , Hartwell H.J.
Published: June 2013

Purpose

Numerous factors can influence an individual's eating behaviour, including the environment where food is purchased and consumed; this has been termed the foodscape. Settings where meals are consumed by the same people habitually, such as that of workplaces, can significantly impact individuals' overall diets, highlighting an opportunity to improve their health. The aim of this study is to investigate the extent to which the foodscape within a university influences consumer food choice, both students and staff.

Design/methodology/approach

A case study approach was taken where ten interviews were conducted with staff (n=5) and students (n=5) in a university establishment. Interviews were transcribed and analysed thematically. Codes were sorted into overarching research categories bringing meaning to the data, which could then be used in conjunction with outlet mapping.

Findings

Results demonstrate that generally consumers were fairly healthy conscious; however, their behaviour did not reflect this. Personal factors were identified and it was also felt that the environment was not supportive or encouraging of healthy eating practices.

Originality/value

The study concluded that while consumers are ultimately responsible for the lifestyle behaviour they lead, the environment has a significant opportunity to encourage healthy behaviour, a fact that is not always embraced by employers. There are a number of underlying or embedded issues in subjects which surfaced during the interview stage of the study. This work, therefore, contributes towards the body of knowledge in the understanding of the role of the foodscape within a workplace setting.