bluuebunny/crossref_metadata_2025 huggingface dataset:
Pathogenesis of solute-free water retention in experimental ascitic cirrhosis: is vasopressin the only culprit?
Authors: Sansoè Giovanni , Aragno Manuela , Mastrocola Raffaella , Parola Maurizio
Published: October 2015

Catecholamines trigger proximal tubular fluid retention and reduce renal excretion of solute-free water. In advanced cirrhosis, non-osmotic hypersecretion of vasopressin (antidiuretic hormone or ADH) is considered the cause of dilutional hyponatraemia, but ADH V2 receptor antagonists are not beneficial in long-term treatment of ascites. To test the hypothesis that water retention in experimental ascitic cirrhosis might depend primarily on adrenergic hyper-function, hormonal status, renal function and tubular free-water reabsorption (TFWR) were assessed in six groups of rats with ascitic cirrhosis: rats with cirrhosis due to 13-week CCl4 (carbon tetrachloride) administration (group G1); cirrhotic rats receiving daily diuretics (0.5 mg/kg furosemide plus 2 mg/kg K+-canrenoate) from the 11th to the 13th week of CCl4 (G2), diuretics associated with guanfacine oral prodrug (α2A-adrenergic receptor agonist and sympatholytic agent) at 2 (G3), 7 (G4) or 10 (G5) mg/kg, or with SSP-004240F1 (V2 receptor antagonist) at 1 mg/kg (G6). Natriuresis was lower in G1 than in G2, G4 and G6 (all P<0.05). Guanfacine, added to diuretics (i.e. G3 compared with G2), reduced serum noradrenaline from 423±22 to 211±41 ng/l (P<0.05), plasma renin activity (PRA) from 35±8 to 9±2 ng/ml/h (P<0.05) and TFWR from 45±8 to 20±6 μl/min (P<0.01). TFWR correlated with plasma aldosterone (r=0.51, P<0.01) and urinary potassium excretion (r=0.90, P<0.001). In ascitic cirrhosis, reduced volaemia, use of diuretics (especially furosemide) and adrenergic hyper-function cause tubular retention of water. Suitable doses of sympatholytic agents are effective aquaretics.
Distance‐based large margin classifier suitable for integrated circuit implementation
Authors: Torres L.C.B. , Castro C.L. , Coelho F. , Sill Torres F. , Braga A.P.
Published: October 2015

A new learning method for classification problems that is suitable for integrated circuit implementation is presented. The method, which outperforms current approaches in many data sets, is based on a structural description of the learning set represented by a planar graph. The final classification function is composed of a hierarchical mixture of local experts, which yields a large margin classifier for the whole learning set. Since it is based only on distance calculations, on‐chip learning can also be executed. The method is also appropriate for online and incremental learning, since model parameters are obtained directly from the data set, without need of user interaction for learning.
Optimal Byzantine attack strategy for distributed localisation with M‐ary quantised data
Authors: Chen Huifang , Xie Lei , Shen Congqi
Published: November 2015

The distributed localisation with M‐ary quantised data at sensor nodes is investigated in the presence of Byzantines from the attacker's perspective. The Byzantine nodes attack the network by transmitting falsified data to the fusion centre (FC) to deteriorate the performance of the distributed target localisation, where the independent and probabilistic Byzantine attack model is considered. By making the determinant of Fisher information matrix be zero, the optimal Byzantine attack strategy, which makes the FC incapable of estimating target location using the data at sensor nodes, is found. Numerical results show that the security performance of the distributed localisation improves sharply as the number of quantisation bits increases. Moreover, the security performance also increases tremendously as the attack probability decreases. Hence, the Byzantine attacker faces a trade‐off between the performance damage and the hazard to be identified.
Directional dual‐band slotted semi‐circular inverted‐F antenna for WLAN applications
Authors: Chen Wei , Yin Jungang , Li Meiju , Li Fuhai , Yang Jian
Published: October 2015

A simple and compact directional dual‐band semi‐circular inverted‐F antenna for wireless local area network applications is reported. Two pairs of semi‐circular slots as well as a pair of arms are employed to generate the dual resonances in the 2.4–2.48 and 5.2–5.8 GHz bands. The measured results show that the proposed antenna can provide two 10 dB impedance bandwidths of 160 MHz (2.40–2.56 GHz) and 900 MHz (4.95–5.85 GHz). Nearly constant directivities (about 4.7 dBi) are observed in the lower band, while directivities in the upper band vary between 6.3 and 8.6 dBi.
Improved high‐frequency output equivalent circuit modelling for MOSFETs
Authors: Hong Seoyoung , Lee Seonghearn
Published: October 2015

An improved MOSFET output equivalent circuit model is proposed to greatly reduce the Y22‐parameter error of a conventional one in the high‐frequency range more than 10 GHz. In this model, a new parallel RC network is connected in series with the drain–source capacitance to model the ac current crowding phenomenon due to the vertically distributed RC effect in the saturation region. Its accuracy is clearly validated by finding much better agreement up to 40 GHz between measured and modelled Y22‐parameter than the conventional one.
Two‐step multi‐stage incremental ADC
Authors: Chen Chia‐Hung , Zhang Yi , He Tao , Temes Gabor C.
Published: October 2015

Multi‐stage noise‐shaping (MASH) is a useful technique for the design of stable high‐order ΔΣ modulators. A two‐step MASH incremental ADC (IADC) is proposed. In the first step it performs a third‐order coarse quantisation. Using the same hardware, in the second step the circuit performs fine quantisation as a second‐order IADC. Thus, it achieves fifth‐order noise shaping with only three amplifiers. For an oversampling ratio OSR = 32, the signal‐to‐noise ratio can be boosted by about 30 dB. The scheme is suitable for wide bandwidth applications.
Three‐octave band in‐phase power divider using loosely coupled microstrip lines and microstrip to slotline transitions
Authors: Ahmed U.T. , Abbosh A.M.
Published: October 2015

A planar microwave in‐phase power divider operating over three‐octave frequency band is presented. The proposed device is composed of two main parts. The first one is a pair of microstrip–slotline–microstrip transitions introduced to match the impedances at the input port. The second one is a pair of loosely coupled microstrip lines with two isolation resistors to provide improved isolation performance at the output ports over a wide range of frequency band. The device has a compact area of 40 × 40 mm using the substrate RO4003C (dielectric constant of 3.38 and thickness of 0.406 mm). The simulated and experimental results of the developed device show three‐octave bandwidths (155% fractional bandwidth) with isolation >15 dB across the investigated band from 1 to 8 GHz. In addition, the device provides a <±2° differential phase between the in‐phase output ports across the whole frequency band.
Compact multi‐band polarisation‐insensitive metamaterial absorber
Authors: Chaurasiya Devkinandan , Ghosh Saptarshi , Bhattacharyya Somak , Bhattacharya Anamiya , Srivastava Kumar Vaibhav
Published: October 2015

In this study, a novel multi‐band metamaterial absorber has been proposed which is ultra‐thin, compact, polarisation‐insensitive and wide‐angle absorptive. The proposed structure comprises two concentric metallic rings printed on a dielectric substrate which is backed by a metal ground plane. The proposed structure exhibits four distinct absorption peaks at 4.11, 7.91, 10.13 and 11.51 GHz with peak absorptivities of 98.81, 99.68, 99.98 and 99.34%, respectively, under normal incidence. The designed absorber is polarisation insensitive due to four‐fold symmetry, which has been confirmed by simulation and measurement studies. Moreover, the structure shows high absorption (over 90%) for oblique incident angles up to 45° for both transverse‐electric and transverse‐magnetic polarisations. The surface current distributions at the four absorption frequencies have been illustrated to explain the absorption mechanism of the structure. In addition, several parametric variations are performed to observe the effects of the geometrical dimensions on the absorption performance. The free space measurement method has been utilised to measure the responses of the fabricated structure, which are in good agreement with the simulated results. The proposed ultra‐thin (∼0.013λ0 thin corresponding to lowest absorption frequency) absorber is anticipated to be useful in various potential applications like stealth technology, electromagnetic interference, electromagnetic compatibility and wireless communication.
Unconditionally stable finite‐difference time‐domain algorithm for analysing composite right‐/left‐handed transmission line
Authors: Afrooz Kambiz
Published: October 2015

An unconditionally stable finite‐difference time‐domain method to analyse the composite right/left handed (CRLH) transmission lines (TLs) is proposed. The conventional algorithm presented to analyse the CRLH TLs is not capable of analysing special case of the CRLH TLs such as pure left‐handed TLs due to numerical stability problem. The proposed unconditionally stable algorithm removes the numerical instability and can analyse all the CRLH and pure left‐handed TLs. Amplification matrix of the proposed algorithm is calculated and numerical stability of the presented algorithm is studied. The proposed algorithm is applied to some examples and results are verified by the results of the conventional algorithm and results of Agilent ADS software. The results indicate that the CPU time of the proposed algorithm is reduced about 99% than that of the conventional algorithm by using the complex phasor method and unconditionally stable algorithm.
Three‐wire bipolar high‐voltage direct current line using an existing single‐circuit high‐voltage alternating current line for integrating renewable energy sources in multiterminal DC networks
Authors: Elserougi Ahmed , Massoud Ahmed Mohamed , Abdel‐Khalik Ayman Samy , Ahmed Shehab
Published: November 2015

When compared with conventional point‐to‐point high‐voltage direct current (HVDC) systems, multiterminal HVDC (MTDC) systems are more economical and flexible. MTDC systems can tie distributed high power renewable energy sources (such as offshore wind energy and high‐power photovoltaic systems) into AC grid(s). To save in the required infrastructure for DC line installations, existing high‐voltage alternating current (HVAC) lines can be converted into DC links. The bipole HVDC concept can be used easily for converting the HVAC lines into DC links, but with a limited transmission capacity. Alternatively, three‐wire bipole structure (TWBS) can be used, yet it requires a power electronics‐based converter connected in series with one of the wires (modulating wire), which affects the system reliability and adds more complexity. In this study, a new configuration is proposed for converting the HVAC lines into DC links with enhanced power capability compared with the two‐wire bipole HVDC system. The proposed approach provides a lower power enhancement compared with that provided by TWBS. However, a higher reliability can be guaranteed as it avoids the series‐connected converters. Analytical and simulation studies using Matlab/Simulink platform have been presented in this study to validate the proposed concept.
Doppler spectra of medium grazing angle sea clutter; part 2: model assessment and simulation
Authors: Watts Simon , Rosenberg Luke , Bocquet Stephen , Ritchie Matthew
Published: November 2015

This study is concerned with the assessment of models of Doppler spectra, derived from high range resolution X‐band radar sea clutter observed from an airborne platform over the range of grazing angles, 15–45°. When looking up or downwind these models represent the strong correlation between mean Doppler shift and local spectrum intensity. When combined with random fluctuations of spectrum width, these characteristics give the spectra a temporal and spatial variability. The models are used to predict clutter spectrum statistics as a function of Doppler frequency and these are compared with statistics derived from the original data. It is also shown how realistic range‐varying coherent clutter returns can be simulated using the models.
Multi‐scale feature‐based fuzzy‐support vector machine classification using radar range profiles
Authors: Liu Jia , Fang Ning , Xie Yong Jun , Wang Bao Fa
Published: November 2015

High resolution range profile possesses great significance in automatic target recognition (ATR) research and application due to its efficiency superiority. Feature extraction is one of the major ATR research directions. Existing feature extraction techniques only concern the range profile in original scale, which constrains the cognitive level of classifiers. This study goes beyond this limitation and introduces scale space theory in the feature extraction of range profiles. The edge points of range profiles are extracted and a novel multi‐scale target classification method based on fuzzy‐support vector machine classifier is proposed. Range profiles of three aircraft models are selected to validate the classification method. Experiment results demonstrate that the addition of edge points is favourable to enhance range profile samples’ separability. Comparison of classification performance between original and multiple scales validates multi‐scale technique's feasibility in range profile classification problem. The weighting factor developed according to the quadratic entropy optimises range profile samples’ membership degree distribution and brings further promotion on classification performance.
Autologous Fat Transfer for Esthetic Contouring of Face in Posttraumatic Nonfunctional Maxillofacial Deformities
Authors: Agrawal Kapil S. , Bachhav Manoj , Naik Charudatta S. , Tanwar Harshwardhan , Sankhe Shilpa S.
Published: November 2015

The transfer of autologous fat has been performed since the 1890s; however, its popularity has increased owing to better understanding of fat harvesting and processing techniques. In this article, fat grafting procedure has been used to correct posttraumatic facial deformities in 25 cases. As healing of grafted fat is unpredictable, we have used longer follow-up of 2 years. Evaluation was performed using facial photographs and MRI scans. Scientific literature describes an absorption rate ranging from 20 to 90%. High fat graft resorption rates have been attributed to traumatic handling of the graft during harvest, processing, and injection. Various processing techniques have been suggested. The goal of these techniques is to obtain greater adipocyte cell survival and, consequently, more reliable clinical results. In our study, we have used syringe aspiration and low-speed centrifuge for processing of fat which has resulted in good clinical outcomes.
Vortex dynamics in thin elliptic ferromagnetic nanodisks
Authors: Wysin G. M.
Published: October 2015

Vortex gyrotropic motion in thin ferromagnetic nanodisks of elliptical shape is described here for a pure vortex state and for a situation with thermal fluctuations. The system is analyzed using numerical simulations of the Landau–Lifshitz–Gilbert (LLG) equations, including the demagnetization field calculated with a Green's function approach for thin film problems. At finite temperature the thermalized dynamics is found using a second order Heun algorithm for a magnetic Langevin equation based on the LLG equations. The vortex state is stable only within a limited range of ellipticity, outside of which a quasi-single-domain becomes the preferred minimum energy state. A vortex is found to move in an elliptical potential, whose force constants along the principal axes are determined numerically. The eccentricity of vortex motion is directly related to the force constants. Elliptical vortex motion is produced spontaneously by thermal fluctuations. The vortex position and velocity distributions in thermal equilibrium are Boltzmann distributions. The results show that vortex motion in elliptical disks can be described by a Thiele equation.
Scattering of high-energy magnons off a magnetic skyrmion
Authors: Schroeter Sarah , Garst Markus
Published: October 2015

We discuss the scattering of high-energy magnons off a single magnetic skyrmion within the field-polarized ground state of a two-dimensional chiral magnet. For wavevectors larger than the inverse skyrmion radius, krs ≫ 1 the magnon scattering is dominated by an emerging magnetic field whose flux density is essentially determined by the topological charge density of the skyrmion texture. This leads to skew and rainbow scattering characterized by an asymmetric and oscillating differential cross section. We demonstrate that the transversal momentum transfer to the skyrmion is universal due to the quantization of the total emerging flux while the longitudinal momentum transfer is negligible in the high-energy limit. This results in a magnon-driven skyrmion motion approximately antiparallel to the incoming magnon current and a universal relation between current and skyrmion-velocity.
Two-stage radio-frequency interferometer sensors
Authors: Osterberg Jeffrey , Wang Pingshan
Published: October 2015

We show that simple radio-frequency (RF) interferometers can have slow-wave positive group delay (PGD) or negative group delay (NGD), as well as superluminal propagation (SP) regions, due to a destructive interference process. These properties are easily tunable, which makes RF interferometers unique among systems that have NGD and SP regimes. A two-stage interferometer arrangement, which includes a first stage interferometer in the material-under-test path of a second stage, has significantly improved sensitivity in comparison with a one-stage reference interferometer. With a power divider based first stage and at its maximum NGD frequency, the frequency sensitivity improvement is as high as 7 times. With a quadrature based first stage, the sensitivity is increased by as much as 20 times. Sensitivity improvements are also observed at PGD and SP frequency regions.
Bonding and structure in dense multi-component molecular mixtures
Authors: Meyer Edmund R. , Ticknor Christopher , Bethkenhagen Mandy , Hamel Sebastien , Redmer Ronald , Kress Joel D. , Collins Lee A.
Published: October 2015

We have performed finite-temperature density functional theory molecular dynamics simulations on dense methane, ammonia, and water mixtures (CH4:NH3:H2O) for various compositions and temperatures (2000 K ≤ T ≤ 10 000 K) that span a set of possible conditions in the interiors of ice-giant exoplanets. The equation-of-state, pair distribution functions, and bond autocorrelation functions (BACF) were used to probe the structure and dynamics of these complex fluids. In particular, an improvement to the choice of the cutoff in the BACF was developed that allowed analysis refinements for density and temperature effects. We note the relative changes in the nature of these systems engendered by variations in the concentration ratios. A basic tenet emerges from all these comparisons that varying the relative amounts of the three heavy components (C,N,O) can effect considerable changes in the nature of the fluid and may in turn have ramifications for the structure and composition of various planetary layers.
Cavitation erosion: Using the target material as a pressure sensor
Authors: Roy Samir Chandra , Franc Jean-Pierre , Fivel Marc
Published: October 2015

Numerical prediction of mass loss due to cavitation erosion requires the knowledge of the hydrodynamic impact loads generated by cavitation bubble collapses. Experimental measurements of such impact loads using conventional pressure sensors are not reliable (if not impossible) due to the micron size and the very small duration of the loading. In this paper, a new method to estimate these loading conditions is proposed based on cavitation pitting tests and an iterative inverse finite element modeling. The principle of the method is as follows. First, numerous pits corresponding to localized plastically deformed regions are identified from a cavitation test performed in a dedicated tunnel. Then each pit is numerically reproduced by finite element simulations of the material response to a representative Gaussian pressure field supposed to mimic a single bubble collapse. This gives the size and pressure distribution of the bubble impacts. The prime objective of this study is to find out if the target material itself could be used as a pressure sensor or not, i.e., if the cavitation pits left on the surface of the tested specimen could provide the characteristics of the cavitating flow in terms of pressure fields independently of the target material. Pitting tests were done on three materials, namely, 7075 Aluminum alloy (Al-7075), 2205 duplex stainless steel (A-2205), and Nickel-Aluminum Bronze (NAB) at three different flow conditions and the impact loads have been estimated for each identified pit. Very interestingly, a statistical analysis shows that the estimated impact loads are material independent at all flow conditions, provided the material properties are characterized properly. It is also shown that for some materials, the constitutive parameters obtained from compression tests are not satisfactory.
A comparative density functional study on electrical properties of layered penta-graphene
Authors: Yu Zhi Gen , Zhang Yong-Wei
Published: October 2015

We present a comparative study of the influence of the number of layers, the biaxial strain in the range of −3% to 3%, and the stacking misalignments on the electronic properties of a new 2D carbon allotrope, penta-graphene (PG), based on hybrid-functional method within the density functional theory (DFT). In comparison with local exchange-correlation approximation in the DFT, the hybrid-functional provides an accurate description on the degree of pz orbitals localization and bandgap. Importantly, the predicted bandgap of few-layer PG has a weak layer dependence. The bandgap of monolayer PG is 3.27 eV, approximately equal to those of GaN and ZnO; and the bandgap of few-layer PG decreases slowly with the number of layers (N) and converge to 2.57 eV when N ≥ 4. Our calculations using HSE06 functional on few-layer PG reveal that bandgap engineering by stacking misalignment can further tune the bandgap down to 1.37 eV. Importantly, there is no direct-to-indirect bandgap transition in PG by varying strain, layer number, and stacking misalignment. Owing to its tunable, robustly direct, and wide bandgap characteristics, few-layer PG is promising for optoelectronic and photovoltaic applications.
Effects of MnO doping on the electronic properties of zinc oxide: 406 GHz electron paramagnetic resonance spectroscopy and Newman superposition model analysis
Authors: Yüksel Price Berat , Hardal Gökhan , Açıkgöz Muhammed , Repp Sergej , Erdem Emre
Published: November 2015

MnO-doped ZnO ceramics have been synthesized through the conventional ceramic processing route. Mn2+ ions have been incorporated into the ZnO lattice within the limits of solid solubility. By using X-band-frequency and high-field electron paramagnetic resonance (EPR), we have resolved some of the main electronic transitions for the S = 5/2, I = 5/2 high-spin system and have determined accurately the EPR spin-Hamiltonian parameters. By combining data from crystallographic X-ray diffraction and EPR with the semi-empirical Newman superposition model, we have found the local configurational position of Mn2+ and have confirmed the symmetry of the lattice. The results presented in this contribution indicate that Mn ions substitute at Zn sites in ZnO. The effect of Mn2+ ions on the intrinsic defects becomes remarkable, thus the vacancy related intrinsic defect signals cannot be visible in the EPR spectrum. MnO doping affects the band gap energy of ZnO system which was confirmed via UV-Vis spectroscopy.
Manipulation of Dy-Mn coupling and ferrielectric phase diagram of DyMn2O5: The effect of Y substitution of Dy
Authors: Zhao Z. Y. , Wang Y. L. , Lin L. , Liu M. F. , Li X. , Yan Z. B. , Liu J.-M.
Published: November 2015

DyMn2O5 is an extraordinary example in the family of multiferroic manganites and it accommodates both the 4f and 3d magnetic ions with strong Dy-Mn (4f-3d) coupling. The electric polarization origin is believed to arise not only from the Mn spin interactions but also from the Dy-Mn coupling. Starting from proposed scenario on ferrielectricity in DyMn2O5 where the exchange-strictions associated with the Mn3+-Mn4+-Mn3+ blocks and Dy3+-Mn4+-Dy3+ blocks generate the two ferroelectric sublattices, we perform a set of characterizations on the structure, magnetism, and electric polarization of Dy1-xYxMn2O5 in order to investigate the roles of Dy-Mn coupling in manipulating the ferrielectricity. It is revealed that the non-magnetic Y substitution of Dy suppresses gradually the Dy3+ spin ordering and the Dy-Mn coupling. Consequently, the ferroelectric sublattice generated by the exchange striction associated with the Dy3+-Mn4+-Dy3+ blocks is destabilized, but the ferroelectric sublattice generated by the exchange striction associated with the Mn3+-Mn4+-Mn3+ blocks remains less perturbed, enabling the ferrielectricity-ferroelectricity transitions with the Y substitution. A phenomenological ferrielectric domain model is suggested to explain the polarization reversal induced by the Y substitution. The present work presents a possible scenario of the multiferroic mechanism in not only DyMn2O5 but probably also other RMn2O5 members with strong 4f-3d coupling.
The effect of ultraviolet irradiation on the ultra-thin HfO2 based CO gas sensor
Authors: Karaduman Irmak , Barin Özlem , Yıldız Dilber Esra , Acar Selim
Published: November 2015

In this work, an effort has been made to fabricate ultrathin HfO2/Al2O3 sample by atomic layer deposition method for the fast detection of CO gas at room temperature. The effect of the operating temperature and the UV light on the gas sensing characteristics has been studied. We investigated the optimum operating temperature for the sample by sensing 25 ppm CO and CO2 gases from room temperature to 150 °C for 10 °C steps. The maximum response was obtained at 150 °C for both gases in the measurement temperature range. Also, the photoresponse measurements clearly show the effect of UV light on the sample. At room temperature, sensor showed superior response (14%) for 5 ppm CO gas. The response time of sensor is 6 s to 5 ppm CO gas concentration. The ultrathin HfO2 based sample shows acceptable gas sensitivity for 5 ppm CO gas at room temperature under UV light irradiation.
Ferrohydrodynamic modeling of magnetic nanoparticle harmonic spectra for magnetic particle imaging
Authors: Dhavalikar Rohan , Maldonado-Camargo Lorena , Garraud Nicolas , Rinaldi Carlos
Published: November 2015

Magnetic Particle Imaging (MPI) is an emerging imaging technique that uses magnetic nanoparticles as tracers. In order to analyze the quality of nanoparticles developed for MPI, a Magnetic Particle Spectrometer (MPS) is often employed. In this paper, we describe results for predictions of the nanoparticle harmonic spectra obtained in a MPS using three models: the first uses the Langevin function, which does not take into account finite magnetic relaxation; the second model uses the magnetization equation by Shliomis (Sh), which takes into account finite magnetic relaxation using a constant characteristic time scale; and the third model uses the magnetization equation derived by Martsenyuk, Raikher, and Shliomis (MRSh), which takes into account the effect of magnetic field magnitude on the magnetic relaxation time. We make comparisons between these models and with experiments in order to illustrate the effects of field-dependent relaxation in the MPS. The models results suggest that finite relaxation results in a significant drop in signal intensity (magnitude of individual harmonics) and in faster spectral decay. Interestingly, when field dependence of the magnetic relaxation time was taken into account, through the MRSh model, the simulations predict a significant improvement in the performance of the nanoparticles, as compared to the performance predicted by the Sh equation. The comparison between the predictions from models and experimental measurements showed excellent qualitative as well as quantitative agreement up to the 19th harmonic using the Sh and MRSh equations, highlighting the potential of ferrohydrodynamic modeling in MPI.
Stretchable conducting gold films prepared with composite MWNT/PDMS substrates
Authors: Manzoor M. U. , Lemoine P. , Dixon D. , Hamilton J. W. J. , Maguire P. D.
Published: October 2015

Novel stretchable conducting films were prepared by depositing gold layers onto polymer nano-composites substrates formed by in-situ crosslinking of polydimethylsiloxane (PDMS) in the presence of multiwall carbon nanotubes (MWNT). The MWNT content interferes with the PDMS cure reaction giving variations in thermal degradation, solvent swelling, mechanical and electrical properties. Tensile cycling experiments were carried out on the gold-coated PDMS and nano-composite substrates SEM analysis and electrical measurements demonstrated that the crack widening and increased electrical resistance observed during strain cycling were reversible. The inclusion of 8 % MWNT into PDMS brought more micro-cracking in the gold layer yet reduced the electrical resistance of the gold-coated samples by 172X at 5 % strain, 38X at 10 % strain and 19X at 20 %. Hence, this improvement in conduction is attributed to assisted-conduction through the MWNT loaded substrate. This mechanism results in a more stable and reproducible electrical behaviour, making electrical conduction less critically dependent on defects in the gold layer.
The island coalescence problem: Scaling of reconnection in extended fluid models including higher-order moments
Authors: Ng Jonathan , Huang Yi-Min , Hakim Ammar , Bhattacharjee A. , Stanier Adam , Daughton William , Wang Liang , Germaschewski Kai
Published: November 2015

As modeling of collisionless magnetic reconnection in most space plasmas with realistic parameters is beyond the capability of today's simulations, due to the separation between global and kinetic length scales, it is important to establish scaling relations in model problems so as to extrapolate to realistic scales. Recently, large scale particle-in-cell simulations of island coalescence have shown that the time averaged reconnection rate decreases with system size, while fluid systems at such large scales in the Hall regime have not been studied. Here, we perform the complementary resistive magnetohydrodynamic (MHD), Hall MHD, and two fluid simulations using a ten-moment model with the same geometry. In contrast to the standard Harris sheet reconnection problem, Hall MHD is insufficient to capture the physics of the reconnection region. Additionally, motivated by the results of a recent set of hybrid simulations which show the importance of ion kinetics in this geometry, we evaluate the efficacy of the ten-moment model in reproducing such results.
Perfect electromagnetic absorption at one-atom-thick scale
Authors: Li Sucheng , Duan Qian , Li Shuo , Yin Qiang , Lu Weixin , Li Liang , Gu Bangming , Hou Bo , Wen Weijia
Published: November 2015

We experimentally demonstrate that perfect electromagnetic absorption can be realized in the one-atom thick graphene. Employing coherent illumination in the waveguide system, the absorbance of the unpatterned graphene monolayer is observed to be greater than 94% over the microwave X-band, 7–13 GHz, and to achieve a full absorption, >99% in experiment, at ∼8.3 GHz. In addition, the absorption characteristic manifests equivalently a wide range of incident angle. The experimental results agree very well with the theoretical calculations. Our work accomplishes the broadband, wide-angle, high-performance absorption in the thinnest material with simple configuration.
Granular crystals: Nonlinear dynamics meets materials engineering
Authors: Porter Mason A. , Kevrekidis Panayotis G. , Daraio Chiara
Published: October 2015

The freedom to choose the size, stiffness, and spatial distribution of macroscopic particles in a lattice makes granular crystals easily tailored building blocks for shock-absorbing materials, sound-focusing devices, acoustic switches, and other exotica.
The Tacoma Narrows Bridge collapse
Authors: Olson Donald W. , Wolf Steven F. , Hook Joseph M.
Published: October 2015

Many physicists and physics students have seen videos of the famous bridge disaster that occurred 75 years ago this month. Some of what they saw was misleading.
Diversity of sharp-wave–ripple LFP signatures reveals differentiated brain-wide dynamical events
Authors: Ramirez-Villegas Juan F. , Logothetis Nikos K. , Besserve Michel
Published: November 2015

Significance

Sharp-wave–ripple (SPW-R) episodes observed in the electrical activity of mammalian hippocampus are traditionally associated to memory consolidation during sleep but have been recently observed during active behavior. Their involvement in various cognitive functions suggests the existence of SPW-R subtypes engaged in distinct neuronal activity patterns at multiple scales. We use concurrent electrophysiological and functional MRI (fMRI) recordings in macaque monkeys to investigate this hypothesis. We discover several subtypes of SPW-R with distinct electrophysiological properties. Importantly, fMRI recordings reveal differences between the large-scale signatures of SPW-R subtypes, indicating differentiated interactions with neocortex, and contributions of neuromodulatory pathways to the SPW-R phenomenon. Understanding the detailed properties of hippocampal SPW-Rs at multiple scales will provide new insights on the function of memory systems.
‘I am a paramount chief, this land belongs to my ancestors’: the reconfiguration of rural authority after Zimbabwe's land reforms
Authors: Mkodzongi Grasian
Published: November 2015

This article explores the reconfiguration of rural authority in the aftermath of Zimbabwe's Fast Track Land Reform Programme, particularly the way the programme has allowed local chiefs to deploy ancestral autochthony as a way of contesting state hegemony over the countryside. It argues that chiefs cannot simply be viewed as undemocratic remnants of colonial rule; instead, a nuanced understanding of their role in rural governance is required.
The “Savvy Interpreter”: Performance and Interpretation in Pindar’s Victory Odes
Authors: Felson Nancy , Parmentier Richard J.
Published: November 2015

Pindar’s epinikia challenge their original audiences to play the role of the “savvy interpreters” of these complex choral praise poems. Their interpretive skillfulness enables them to overcome obstacles purposively set by the poet. The ideal interpretation, an “entextualized” and overarching “metapragmatic interpretant,” is not static since these odes invite their hearers to vicariously travel alongside the deictically calibrated narrative ego and, equipped with insight drawn from interwoven exemplary myths and gnomic maxims, to insure that momentary praise for victors leads to their widespread if not immortal “glory” (kleos). The central argument of the article is that the odes develop an extended analogy between athletic prowess/victory and poetic excellence/performance that links the generation of kleos with the potential for recontextualized reperformances. This semiotically mediated “pragmatic” process is originally modelled by the poetic ego and then sequentially constructed and enacted/performed by savvy interpreters, including later readers.
Bayesian inference with historical data-based informative priors improves detection of differentially expressed genes
Authors: Li Ben , Sun Zhaonan , He Qing , Zhu Yu , Qin Zhaohui S.
Published: October 2015

Motivation: Modern high-throughput biotechnologies such as microarray are capable of producing a massive amount of information for each sample. However, in a typical high-throughput experiment, only limited number of samples were assayed, thus the classical ‘large p, small n’ problem. On the other hand, rapid propagation of these high-throughput technologies has resulted in a substantial collection of data, often carried out on the same platform and using the same protocol. It is highly desirable to utilize the existing data when performing analysis and inference on a new dataset.

Results: Utilizing existing data can be carried out in a straightforward fashion under the Bayesian framework in which the repository of historical data can be exploited to build informative priors and used in new data analysis. In this work, using microarray data, we investigate the feasibility and effectiveness of deriving informative priors from historical data and using them in the problem of detecting differentially expressed genes. Through simulation and real data analysis, we show that the proposed strategy significantly outperforms existing methods including the popular and state-of-the-art Bayesian hierarchical model-based approaches. Our work illustrates the feasibility and benefits of exploiting the increasingly available genomics big data in statistical inference and presents a promising practical strategy for dealing with the ‘large p, small n’ problem.

Availability and implementation: Our method is implemented in R package IPBT, which is freely available from https://github.com/benliemory/IPBT.

Contact:  yuzhu@purdue.edu; zhaohui.qin@emory.edu

Supplementary information:  Supplementary data are available at Bioinformatics online.
Probing cosmology with weak lensing selected clusters. II. Dark energy and f(R) gravity models
Authors: Shirasaki Masato , Hamana Takashi , Yoshida Naoki
Published: October 2015

Ongoing and future wide-field galaxy surveys can be used to locate a number of clusters of galaxies with cosmic shear measurement alone. We study constraints on cosmological models using statistics of weak lensing selected galaxy clusters. We extend our previous theoretical framework to model the statistical properties of clusters in variants of cosmological models as well as in the standard ΛCDM model. Weak lensing selection of clusters does not rely on conventional assumptions such as the relation between luminosity and mass and/or hydrostatic equilibrium, but a number of observational effects compromise robust identification. We use a large set of realistic mock weak lensing catalogs as well as analytic models to perform a Fisher analysis and make a forecast for constraining two competing cosmological models, the wCDM model and f(R) model proposed by Hu and Sawicki (2007, Phys. Rev. D, 76, 064004), with our lensing statistics. We show that weak lensing selected clusters are excellent probes of cosmology when combined with cosmic shear power spectrum even in the presence of galaxy shape noise and masked regions. With the information from weak lensing selected clusters, the precision of cosmological parameter estimates can be improved by a factor of ∼1.6 and ∼8 for the wCDM model and f(R) model, respectively. The Hyper Suprime-Cam survey with sky coverage of 1250 degrees squared can constrain the equation of state of dark energy w0 with a level of Δw0 ∼ 0.1. It can also constrain the additional scalar degree of freedom in the f(R) model with a level of |fR0| ∼ 5 × 10−6, when constraints from cosmic microwave background measurements are incorporated. Future weak lensing surveys with sky coverage of 20000 degrees squared will place tighter constraints on w0 and |fR0| even without cosmic microwave background measurements.
What’s New in the Orthopaedic Treatment of Cerebral Palsy
Authors: Aversano Michael W. , Sheikh Taha Abdel M. , Mundluru Surya , Otsuka Norman Y.
Published: October 2015

Background:

The orthopaedic treatment of the patient with cerebral palsy (CP) is complex and must take into account the heterogeneity and natural history of the condition. Although the goals of management are for the most part universal, the specific interventions and outcome measures used to reach these goals are wide ranging. This update serves to summarize some of the recent publications in the field of pediatric orthopaedics that have made important contributions to our understanding and care of the patient with CP.

Methods:

We searched the PubMed database using the following terms: “cerebral palsy” AND “orthopedic.” The results were then filtered to include only review papers or clinical trials published in English from 2010 to 2014. The obtained list of references was then reviewed for publications in the fields of lower extremity muscle imbalance, foot and ankle deformities, hip and acetabular dysplasia, and advances in orthopaedic-related technology.

Results:

Updates in the field of pediatric orthopaedics are constant and the current level of evidence for the effectiveness of specific treatment modalities in patients with CP was reviewed. The search method yielded 153 publications, of which 31 papers were identified as having contributed important new findings.

Conclusions:

Our understanding of orthopaedic treatments for children with CP continues to grow and expand. The studies reviewed illustrate just some of the strides we have taken in utilizing evidence-based surgical decision making in practice. Nevertheless, there remains a paucity of randomized controlled trials and higher evidence research, which may contribute to the variability in current practices among providers. By elucidating these gaps we can more purposefully delegate our time and resources into targeted areas of research.

Level of Evidence:

Level 4—literature review.
Utility of the AAOS Appropriate Use Criteria (AUC) for Pediatric Supracondylar Humerus Fractures in Clinical Practice
Authors: Ibrahim Talal , Hegazy Abdelsalam , Abulhail Safa I.S. , Ghomrawi Hassan M.K.
Published: October 2015

Background:

The American Academy of Orthopaedic Surgeons (AAOS) recently developed an Appropriate Use Criteria (AUC) for pediatric supracondylar humerus fractures (PSHF). The AUC is intended to improve quality of care by informing surgeon decision making. The aim of our study was to cross-reference the management of operatively treated PSHF with the AAOS-published AUC.

Methods:

The AUC for PSHF include 220 patient scenarios, based on different combinations of 6 factors. For each patient scenario, 8 treatment options are evaluated as “appropriate,” “maybe appropriate,” and “rarely appropriate.” We retrospectively reviewed the medical charts and radiographs of all operatively treated PSHF at our hospital from January 2013 to December 2014 and determined the appropriateness of the treatment.

Results:

Over the study period, 94 children (mean age: 5.2 y; 51 male, 43 female) were admitted with PSHF and underwent a surgical procedure (type IIA: 7, type IIB: 14, type III: 70, flexion type: 3). Only 8 of the 220 scenarios were observed in our patient cohort. The most frequent scenario was represented by a type III fracture, palpable distal pulse, no nerve injury, closed soft-tissue envelope, no radius/ulna fracture, and typical swelling. Of the 94 fractures, the AUC was “appropriate” for 84 cases and “maybe appropriate” for 9 cases. There was only 1 case of “rarely appropriate” management. Closed reduction with lateral pinning and immobilization was the most prevalent treatment option (58.5%). The rate of appropriateness was not affected by the operating surgeon. However, the definition of a case as emergent had a significant impact on the rate of appropriateness.

Conclusions:

Application of the AUC to actual clinical data was relatively simple. The majority of operatively treated PSHF (89.4%) were managed appropriately. With the introduction of electronic medical charts, an AUC application becomes attractive and easy for orthopaedic surgeons to utilize in clinical practice. However, validity studies of the AUC in different clinical settings are still required.

Level of Evidence:

Level IV.
Clinical Outcomes of Patients With Gastrointestinal Malignancies Participating in Phase I Clinical Trials
Authors: Denson Aaron , Burke Nancy , Wapinsky Georgine , Bertels Barbara , Juan Tzu-Hua , Lee Jae , Springett Gregory M. , Strosberg Jonathan R. , Kim Richard D. , Sullivan Dan M. , Mahipal Amit
Published: October 2015

Objectives:

Early-phase clinical trials play a pivotal role in drug development. However, limited data are available on outcomes of gastrointestinal (GI) cancer patients enrolled in phase I clinical trials. Here, we evaluated the characteristics associated with survival in GI cancer patients participating in phase I clinical trials and attempted to validate previously established prognostic models.

Materials and Methods:

All consecutive patients with advanced GI tumors who participated in phase I clinical trials at our institution from January 2007 to December 2013 and received at least 1 dose of the study drug were included. Cox regression models were used to estimate multivariable-adjusted hazard ratio (HR) and 95% confidence interval.

Results:

In 243 study patients (median age, 62 y [range, 26 to 82 y]; 55% male), treatment included chemotherapy only (14%), targeted therapy (41%), chemotherapy+targeted therapy (42%), and others (2%) for the following disease types: pancreatic (42%), colorectal (34%), gastroesophageal (10%), hepatobiliary (13%), and others (2%). Response rate was 4%, with 38% achieving stable disease and 42% having progressive disease. Median survival was 5.8 months (range, 0.2 to 52.4 mo). Our multivariable Cox regression analyses included the following as predictors of survival: Eastern Cooperative Oncology Group performance score ≥1 (HR=1.76), prior systemic therapies ≥2 (HR=1.63), lactate dehydrogenase >618 IU/L (HR=1.85), sodium >135 mmol/L (HR=0.46), and white blood count >6×109/L (HR=1.5). Our data set was consistent with previous prognostic scores.

Conclusions:

This is the largest study to assess clinical outcomes in this patient population. Phase I trials provide clinical benefit to patients with advanced GI malignancies and should be recommended as a treatment option in appropriate patients.
Predictors of the Health-Promoting Behaviors of Nepalese Migrant Workers
Authors: Bhandari Pratibha , Kim MiYoung
Published: October 2015

Background:

Health-promoting behaviors assist individuals to prevent disease, promote health, increase longevity, and enjoy a better quality of life. A number of interpersonal, social, and environmental factors have been shown to influence health-promoting behaviors. Little empirical evidence exists about the predictors of health-promoting behaviors among migrant workers.

Purpose:

This study uses Pender’s health promotion model to describe and identify the predictors of health-promoting behaviors in Nepalese migrant workers in Korea.

Methods:

A cross-sectional research design was used. Nepalese migrants who had been working in South Korea (n = 169) for over 6 months were surveyed between July and December 2012. Self-efficacy was measured using the Perceived Health Competence Scale, the Health-Promoting Lifestyle Profile II was used to measure health-promoting lifestyle behaviors, and perceived health status was measured using a single-item question. Descriptive statistics, correlation analysis, and multiple regression analysis were used to analyze data.

Results:

Spiritual activity was the highest reported health-promoting behavior, whereas physical activity was the least practiced behavior. Self-efficacy was the only significant predictor of health-promoting behavior.

Conclusions:

The results of this study suggest that future health-promoting interventions should enhance the self-efficacy of target populations for individual health behaviors. Factors such as working conditions, culture, and economic background that may affect the health-promoting behaviors of migrant workers must be considered when planning nursing interventions. Multicultural nursing structures and policies are needed to reach out proactively to all adult migrant groups.