bluuebunny/crossref_metadata_2025 huggingface dataset:
Digital differential protection technique of transmission line using instantaneous active current: theory, simulation and experiment
Authors: Deng Xiangtian , Yuan Rongxiang , Li Timing , Liu Wang , Shen Yangwu , Xiao Zhenfeng
Published: May 2015

Current differential protection is widely used as the main protection in UHV/EHV (Ultra/Extra High Voltage) transmission lines with advantages of simple principle, high reliability and inherent phase‐selection capacity. However, as the voltage level and line length increase, the performance of the current differential protection is severely restricted by distributed capacity current. Aimed at this problem, a rapid extraction method of single‐phase active current is proposed in this paper. The method first uses single PLL (phase‐locked loop) to track the phase of the corresponding fundamental voltage. Then the current signal is transformed from the abc static coordinate system to the pq rotating coordinate through transformation matrix. By filtering out the high‐frequency AC signal on p axis with low‐pass filter, the active current component remaining being in the same direction with voltage phase can be obtained. On this basis, a novel active current differential protection method is proposed, with the advantages of high sensitivity and strong capacity of enduring transition resistance without requirement for the acquisition of line impedance parameters. Finally, the proposed method is tested by a series of dynamic simulations through PSCAD and experiment. The simulation results show that the method has merits of effectiveness, robustness and rapidity.
Patterns of use, perceived benefits and reported effects of access to navigation support systems: an inter‐European field operational test
Authors: Karlsson I.C. MariAnne , Skoglund Tor , Wallgren Pontus , Alonso María , Guidotti Leandro , Martin Oscar , May Andrew
Published: May 2015

The study presents findings regarding drivers’ patterns of use, attitude towards, and reported effects of access to mature nomadic navigation support systems. Three different systems were tested by 582 drivers in four‐field operational tests for a period of six months. A majority of the participants used the support system for trips where the route/destination was unfamiliar but there were also other use scenarios. The main benefits entailed convenience and comfort. Reported effects involved increased possibilities to choose the route according to preferences; a decrease in the time it took to reach destinations and in the distance covered to reach the destination. One in four reported a decrease in fuel consumption attributed an increased compliance with speed limits and/or that driving around and searching for the correct route to reach the desired destination could be avoided. A majority reported ‘no change’ regarding the number of journeys made by car. Reported effects (whether increases or decreases) were however smaller than expected before the trial.
Multi‐domain analysis of photovoltaic impacts via integrated spatial and probabilistic modelling
Authors: Rowley Paul , Leicester Philip , Palmer Diane , Westacott Paul , Candelise Chiara , Betts Thomas , Gottschalg Ralph
Published: May 2015

replace with: Currently, the impacts of wide‐scale implementation of photovoltaic (PV) technology are evaluated in terms of such indicators as rated capacity, energy output or return on investment. However, as PV markets mature, consideration of additional impacts (such as electricity transmission and distribution infrastructure or socio‐economic factors) is required to evaluate potential costs and benefits of wide‐scale PV in relation to specific policy objectives. This study describes a hybrid GIS spatio‐temporal modelling approach integrating probabilistic analysis via a Bayesian technique to evaluate multi‐scale/multi‐domain impacts of PV. First, a wide‐area solar resource modelling approach utilising GIS‐based dynamic interpolation is presented and the implications for improved impact analysis on electrical networks are discussed. Subsequently, a GIS‐based analysis of PV deployment in an area of constrained electricity network capacity is presented, along with an impact analysis of specific policy implementation upon the spatial distribution of increasing PV penetration. Finally, a Bayesian probabilistic graphical model for assessment of socio‐economic impacts of domestic PV at high penetrations is demonstrated. Taken together, the results show that integrated spatio‐temporal probabilistic assessment supports multi‐domain analysis of the impacts of PV, thereby providing decision makers with a tool to facilitate deliberative and systematic evidence‐based policy making incorporating diverse stakeholder perspectives.
Design and construction of TiO2 nanotubes in microarray using two‐step anodic oxidation for application of cardiovascular implanted devices
Authors: Xiang Li‐jie , Li Jing‐an , He Zi‐kun , Wu Jue‐jue , Yang Ping , Huang Nan
Published: May 2015

In recent years, the surface modification of biomaterials has become a hot scientific topic and has rapidly generated huge research interest in several technological areas. The fabrication of titanium dioxide (TiO2) films and their modification for the purpose of excellent biocompatibility have been widely researched and gradually applied for cardiovascular implanted devices. In this reported work, to obtain a novel TiO2 film that possesses anticoagulant, anti‐hyperplasia and pro‐endothelialisation properties simultaneously, TiO2 nanotubes with 100 nm diameter were prepared on the microarray using a two‐step anodic oxidation method. The topography of the micro/nanocomposite TiO2 film was investigated by scanning electron microscopy. Whole‐blood experiments on the film were conducted. The number, morphology and functional factors release of endothelial cells (ECs) on the film were evaluated, and the number of smooth muscle cells (SMCs) on the film was counted. The experimental results demonstrated that the micro/nanocomposite TiO2 film possessed excellent blood compatibility, EC, compatibility and SMC compatibility, thus suggesting potential application for cardiovascular implanted devices.
A compact and low-weight sputtering unit for in situ investigations of thin film growth at synchrotron radiation beamlines
Authors: Walter P. , Dippel A.-C. , Pflaum K. , Wernecke J. , van den Hurk J. , Blume J. , Klemradt U.
Published: May 2015

In this work, we report on a highly variable, compact, and light high-vacuum sputter deposition unit designed for in situ experiments using synchrotron radiation facilities. The chamber can be mounted at various synchrotron beamlines for scattering experiments in grazing incidence geometry. The sample position and the large exit window allow to perform x-ray experiments up to large q values. The sputtering unit is easy to mount on existing experimental setups and can be remote-controlled. In this paper, we describe in detail the design and the performance of the new sputtering chamber and present the installation of the apparatus at different 3rd generation light sources. Furthermore, we describe the different measurement options and present some selected results. The unit has been successfully commissioned and is now available for users at PETRA III at DESY.
Fracture strength of micro- and nano-scale silicon components
Authors: DelRio Frank W. , Cook Robert F. , Boyce Brad L.
Published: May 2015

Silicon devices are ubiquitous in many micro- and nano-scale technological applications, most notably microelectronics and microelectromechanical systems (MEMS). Despite their widespread usage, however, issues related to uncertain mechanical reliability remain a major factor inhibiting the further advancement of device commercialization. In particular, reliability issues related to the fracture of MEMS components have become increasingly important given continued reductions in critical feature sizes coupled with recent escalations in both MEMS device actuation forces and harsh usage conditions. In this review, the fracture strength of micro- and nano-scale silicon components in the context of MEMS is considered. An overview of the crystal structure and elastic and fracture properties of both single-crystal silicon (SCS) and polycrystalline silicon (polysilicon) is presented. Experimental methods for the deposition of SCS and polysilicon films, fabrication of fracture-strength test components, and analysis of strength data are also summarized. SCS and polysilicon fracture strength results as a function of processing conditions, component size and geometry, and test temperature, environment, and loading rate are then surveyed and analyzed to form overarching processing-structure-property-performance relationships. Future studies are suggested to advance our current view of these relationships and their impacts on the manufacturing yield, device performance, and operational reliability of micro- and nano-scale silicon devices.
Optimizing the emission, propagation, and focusing of an intense electron beam
Authors: Pepitone K. , Gardelle J. , Modin P.
Published: May 2015

Intense electron beams can be used to study the dynamical response of materials under shocks in order to adjust the models developed for hydrodynamics simulations. We present in this paper a characterization of beams produced in a field emission diode coupled to the generator RKA at CEA/CESTA. Cherenkov emission, produced by the beam interacting in a fused silica disk, was observed by fast optical cameras to estimate beam homogeneity. GEANT4 simulations were performed to estimate the transfer function of the silica target and to optimize the anode foil. First, we chose the best cathode material available among the most common materials used in field emission systems. In addition, we found that by optimization of the anode thickness, we could improve the spatial homogeneity of the beam which is of prime importance for computing the interaction of the beam with materials. Next, we changed the beam fluence by increasing the beam current and by reducing the beam radius. Finally, we studied the propagation and focusing of the electron beam in low pressure gases and observed that we could use self-magnetic field focusing in order to increase beam fluence at the target location. The experimental results are in good agreement with PIC simulations.
Spreading of a ferrofluid core in three-stream micromixer channels
Authors: Wang Zhaomeng , Varma V. B. , Xia Huan Ming , Wang Z. P. , Ramanujan R. V.
Published: May 2015

Spreading of a water based ferrofluid core, cladded by a diamagnetic fluid, in three-stream micromixer channels was studied. This spreading, induced by an external magnetic field, is known as magnetofluidic spreading (MFS). MFS is useful for various novel applications where control of fluid-fluid interface is desired, such as micromixers or micro-chemical reactors. However, fundamental aspects of MFS are still unclear, and a model without correction factors is lacking. Hence, in this work, both experimental and numerical analyses were undertaken to study MFS. We show that MFS increased for higher applied magnetic fields, slower flow speed of both fluids, smaller flow rate of ferrofluid relative to cladding, and higher initial magnetic particle concentration. Spreading, mainly due to connective diffusion, was observed mostly near the channel walls. Our multi-physics model, which combines magnetic and fluidic analyses, showed, for the first time, excellent agreement between theory and experiment. These results can be useful for lab-on-a-chip devices.
Designing pH induced fold switch in proteins
Authors: Baruah Anupaul , Biswas Parbati
Published: May 2015

This work investigates the computational design of a pH induced protein fold switch based on a self-consistent mean-field approach by identifying the ensemble averaged characteristics of sequences that encode a fold switch. The primary challenge to balance the alternative sets of interactions present in both target structures is overcome by simultaneously optimizing two foldability criteria corresponding to two target structures. The change in pH is modeled by altering the residual charge on the amino acids. The energy landscape of the fold switch protein is found to be double funneled. The fold switch sequences stabilize the interactions of the sites with similar relative surface accessibility in both target structures. Fold switch sequences have low sequence complexity and hence lower sequence entropy. The pH induced fold switch is mediated by attractive electrostatic interactions rather than hydrophobic-hydrophobic contacts. This study may provide valuable insights to the design of fold switch proteins.
Basic knowledge on radiative and transport properties to begin in thermal plasmas modelling
Authors: Cressault Y.
Published: May 2015

This paper has for objectives to present the radiative and the transport properties for people beginning in thermal plasmas. The first section will briefly recall the equations defined in numerical models applied to thermal plasmas; the second section will particularly deal with the estimation of radiative losses; the third part will quickly present the thermodynamics properties; and the last part will concern the transport coefficients (thermal conductivity, viscosity and electrical conductivity of the gas or mixtures of gases). We shall conclude the paper with a discussion about the validity of these results the lack of data for some specific applications, and some perspectives concerning these properties for non-equilibrium thermal plasmas.
Threshold photoelectron spectroscopy of unstable N-containing compounds: Resolution of ΔK subbands in HNCO+ and vibrational resolution in NCO+
Authors: Holzmeier Fabian , Lang Melanie , Fischer Ingo , Tang Xiaofeng , Cunha de Miranda Barbara , Romanzin Claire , Alcaraz Christian , Hemberger Patrick
Published: May 2015

The threshold photoelectron spectra (TPES) of two unstable nitrogen-containing species, HNCO and NCO, were recorded utilizing vacuum ultraviolet synchrotron radiation. Both are intermediates in combustion processes and play a role in the removal of nitrogen oxides from exhaust gases. The rovibronic structure of the first band in the TPES of HNCO+ was analyzed within the framework of an orbital ionization model, and the resolved structure of the origin band was assigned to ΔK subbands. An ionization energy of 11.602 ± 0.005 eV was determined and the vibrational structure of the cationic ground state was analyzed by a Franck-Condon fit. Low lying electronically excited states of HNCO+ were also observed. In a second series of experiments, the NCO radical was generated by flash pyrolysis from chlorine isocyanate. The ionization energy to the X+ 3Σ− ground state was determined to be 11.76 ± 0.02 eV, while for the a+ 1Δ state, a value of 12.93 ± 0.02 eV was obtained. Vibrational structure was observed for both states, and bands were assigned by Franck-Condon simulations.
Charge-carrier dynamics in polycrystalline thin-film CuIn1−xGaxSe2 photovoltaic devices after pulsed laser excitation: Interface and space-charge region analysis
Authors: Kuciauskas Darius , Li Jian V. , Kanevce Ana , Guthrey Harvey , Contreras Miguel , Pankow Joel , Dippo Pat , Ramanathan Kannan
Published: May 2015

We used time-resolved photoluminescence (TRPL) spectroscopy to analyze time-domain and spectral-domain charge-carrier dynamics in CuIn1−xGaxSe2 (CIGS) photovoltaic (PV) devices. This new approach allowed detailed characterization for the CIGS/CdS buffer interface and for the space-charge region. We find that dynamics at the interface is dominated by diffusion, where the diffusion rate is several times greater than the thermionic emission or interface recombination rate. In the space-charge region, the electric field of the pn junction has the largest effect on the carrier dynamics. Based on the minority-carrier (electron) drift-rate dependence on the electric field strength, we estimated drift mobility in compensated CuIn1−xGaxSe2 (with x ≈ 0.3) as 22 ± 2 cm2(Vs)−1. Analysis developed in this study could be applied to evaluate interface and junction properties of PV and other electronic devices. For CIGS PV devices, TRPL spectroscopy could contribute to understanding effects due to absorber compositional grading, which is one of the focus areas in developing record-efficiency CIGS solar cells.
The comprehensive study and the reduction of contact resistivity on the n-InGaAs M-I-S contact system with different inserted insulators
Authors: Liao M.-H. , Lien C.
Published: May 2015

Five different kinds of insulators including BaTiO3, TiO2, Al2O3, CdO and ZnO on the n-type InGaAs metal-insulator-semiconductor (M-I-S) ohmic contact structure are studied. The effect for the dielectric constant (ε) of inserted insulator and the conduction band offset (CBO) between an insulator and semiconductor substrate is analyzed by a unified M-I-S contact model. Based on the theoretical model and experimental data, we demonstrates that the inserted ZnO insulator with the high electron affinity and the low CBO (∼0.1 eV) to the InGaAs substrate results in ∼10 times contact resistivity reduction, even the ε of ZnO is not pretty high (∼10).
Visualizing ferromagnetic domains in magnetic topological insulators
Authors: Wang Wenbo , Yang Fang , Gao Chunlei , Jia Jinfeng , Gu G. D. , Wu Weida
Published: May 2015

We report a systematic study of ferromagnetic domains in both single-crystal and thin-film specimens of magnetic topological insulators Cr doped (Bi0.1Sb0.9)2Te3 using magnetic force microscopy (MFM). The temperature and field dependences of MFM and in situ resistance data are consistent with previous bulk transport and magnetic characterization. Bubble-like ferromagnetic domains were observed in both single crystals and thin films. Significantly, smaller domain size (∼500 nm) with narrower domain wall (∼150 − 300 nm) was observed in thin films of magnetic topological insulators, likely due to vertical confinement effect. These results suggest that thin films are more promising for visualization of chiral edge states.
Optical phonon modes in rhombohedral boron monosulfide under high pressure
Authors: Cherednichenko Kirill A. , Sokolov Petr S. , Kalinko Aleksandr , Le Godec Yann , Polian Alain , Itié Jean-Paul , Solozhenko Vladimir L.
Published: May 2015

Raman spectra of rhombohedral boron monosulfide (r-BS) were measured under pressures up to 34 GPa at room temperature. No pressure-induced structural phase transition was observed, while strong pressure shift of Raman bands towards higher wavenumbers has been revealed. IR spectroscopy as a complementary technique has been used in order to completely describe the phonon modes of r-BS. All experimentally observed bands have been compared with theoretically calculated ones and modes assignment has been performed. r-BS enriched by 10B isotope was synthesized, and the effect of boron isotopic substitution on Raman spectra was observed and analyzed.
Graphene nanoribbons: Relevance of etching process
Authors: Simonet P. , Bischoff D. , Moser A. , Ihn T. , Ensslin K.
Published: May 2015

Most graphene nanoribbons in the experimental literature are patterned using plasma etching. Various etching processes induce different types of defects and do not necessarily result in the same electronic and structural ribbon properties. This study focuses on two frequently used etching techniques, namely, O2 plasma ashing and O2 + Ar reactive ion etching (RIE). O2 plasma ashing represents an alternative to RIE physical etching for sensitive substrates, as it is a more gentle chemical process. We find that plasma ashing creates defective graphene in the exposed trenches, resulting in instabilities in the ribbon transport. These are probably caused by more or larger localized states at the edges of the ashed device compared to the RIE defined device.
Radio frequency substrate biasing effects on the insulator-metal transition behavior of reactively sputtered VO2 films on sapphire (001)
Authors: Azhan Nurul Hanis , Su Kui , Okimura Kunio , Sakai Joe
Published: May 2015

Comprehensive studies have been performed on the effects of radio frequency (rf) substrate biasing on insulator–metal transition (IMT) properties of VO2 thin films grown on Al2O3 (001) substrates. As the rf substrate bias power increased, the ion energy during deposition increased, inducing a strong in-plane stress conversion and a modification of the rutile c-axis (cR-axis) length in the VO2 films. The reduced cR-axis length significantly lowered the IMT temperature. Increased IMT sharpness via improved crystallinity was obtained with rf substrate biasing at an appropriate power. Temperature coefficient of resistance at room temperature was comparable with reported values for impurity-doped VO2 films. Thus, the rf substrate biasing during reactive sputtering has great potential to control stress in thin films, which could finally control the IMT in oriented VO2 films.
On the importance of collective excitations for thermal transport in graphene
Authors: Gill-Comeau Maxime , Lewis Laurent J.
Published: May 2015

We use equilibrium molecular dynamics (MD) simulations to study heat transport in bulk single-layer graphene. Through a modal analysis of the MD trajectories employing a time-domain formulation, we find that collective excitations involving flexural acoustic (ZA) phonons, which have been neglected in the previous MD studies, actually dominate the heat flow, generating as much as 78% of the flux. These collective excitations are, however, much less significant if the atomic displacements are constrained in the lattice plane. Although relaxation is slow, we find graphene to be a regular (non-anomalous) heat conductor for sample sizes of order 40 μm and more.
Spin-crossover molecule based thermoelectric junction
Authors: Ghosh Dibyajyoti , Parida Prakash , Pati Swapan K.
Published: May 2015

Using ab-initio numerical methods, we explore the spin-dependent transport and thermoelectric properties of a spin-crossover molecule (i.e., iron complex of 2-(1H-pyrazol-1-yl)-6-(1H-tetrazole-5-yl)pyridine) based nano-junction. We demonstrate a large magnetoresistance, efficient conductance-switching, and spin-filter activity in this molecule-based two-terminal device. The spin-crossover process also modulates the thermoelectric entities. It can efficiently switch the magnitude as well as spin-polarization of the thermocurrent. We find that thermocurrent is changed by ∼4 orders of magnitude upon spin-crossover. Moreover, it also substantially affects the thermopower and consequently, the device shows extremely efficient spin-crossover magnetothermopower generation. Furthermore, by tuning the chemical potential of electrodes into a certain range, a pure spin-thermopower can be achieved for the high-spin state. Finally, the reasonably large values of figure-of-merit in the presence and absence of phonon demonstrate a large heat-to-voltage conversion efficiency of the device. We believe that our study will pave an alternative way of tuning the transport and thermoelectric properties through the spin-crossover process and can have potential applications in generation of spin-dependent current, information storage, and processing.
Formation of a silicon terminated (100) diamond surface
Authors: Schenk Alex , Tadich Anton , Sear Michael , O'Donnell Kane M. , Ley Lothar , Stacey Alastair , Pakes Chris
Published: May 2015

We report the preparation of an ordered silicon terminated diamond (100) surface with a two domain 3 × 1 reconstruction as determined by low energy electron diffraction. Based on the dimensions of the surface unit cell and on chemical information provided by core level photoemission spectra, a model for the structure is proposed. The termination should provide a homogeneous, nuclear, and electron spin-free surface for the development of future near-surface diamond quantum device architectures.
The role of contact resistance in GeTe and Ge2Sb2Te5 nanowire phase change memory reset switching current
Authors: Hwang Inchan , Cho Yong-Jun , Lee Myoung-Jae , Jo Moon-Ho
Published: May 2015

Nanowire (NW) structures offer a model system for investigating material and scaling properties of phase change random access memory (PCRAM) at the nanometer scale. Here, we investigate the relationship between nanowire device contact resistance and reset current (Ireset) for varying diameters of NWs. Because the reset switching current directly affects possible device density of PCRAM NWs, it is considered one of the most important parameters for PCRAM. We found that the reset switching current, Ireset, was inversely proportional to the contact resistance of PCRAM NW devices decreasing as NW diameter was reduced from 250 nm to 20 nm. Our observations suggest that the reduction of power consumption of PCRAM in the sub-lithographic regime can be achieved by lowering the contact resistance.
Alginate-Coated Fe3O4 Hollow Microspheres for Drug Delivery
Authors: Dong Li-juan , Jin Gu
Published: May 2015

Novel hollow Fe3O4 nanoparticles for drug delivery were synthesized via a one-step template-free approach. These nanoparticles were obtained by modifing the Fe3O4 nanoparticles with 3-aminopropyltrimethoxy silane, and then grafting alginate onto the surface of amine magnetic. The hollow structure of Fe3O4 spheres was characterized by TEM, XRD, and XPS. The M-H hysteresis loop indicated that the magnetic spheres exhibit superparamagnetic characteristics at room temperature. Daunorubicin acting as a model drug was loaded into the carrier, and the maximum percent of envelop and load were 28.4% and 14.2% respectively. The drug controlled releasing behaviors of the carriers were compared in different pH media.
Effect of Calcined Temperature on Coke Deposition for Autothermal Reforming of Methane with Ni-Cu Catalyst
Authors: Cai Xiu-lan , Li Guang-yan , Lin Wei-ming
Published: May 2015

Ni-Cu/ZrO2-CeO2-Al2O3 catalysts were prepared by co-precipitation method at pH=9 and using Na2CO3 as the precipitant. The Ni loading (mass fraction) of the catalysts was 10%. The catalysts were characterized by X-ray diffraction, temperature-programmed oxidation (TPO), scanning electron microscope (SEM), and X-ray photoelectron spectroscopy (XPS). The effects of calcined temperature of support on coke deposition were studied. TPO, SEM and XPS results indicated there was no peak of higher temperature oxygen consumption on Ni-Cu/ZrO2-CeO2-Al2O3 catalyst (support was calcined at 800 °C), which could lead to the deactivation of the catalyst. The carbon species were carbonate and inactive carbon (filamentous carbon species) on the surface of catalyst reacting for 40 h which perhaps led to the deactivation of the catalyst.
Synthesis and Photoluminescence of Amorphous Silicon Oxycarbide Nanowires
Authors: Wang Qiu-shi , Zhang Wei , Zhong Min , Ma Jin-wen , Wu Zhi-ying , Wang Gui-qiang
Published: May 2015

Synthesis of amorphous SiCO nanowires was carried out by means of direct current arc discharge. Free-standing SiCO nanowires were deposited on the surface of a graphite crucible without any catalyst and template. The SiCO nanowires were analyzed by XRD, SEM, TEM, XPS, and FTIR. The SiCO nanowires were typically 20–100 μm in length and 10–100 nm in diameter as measured by SEM and TEM. The XPS and FTIR spectroscopy analysis confirmed that the Si atoms share bonds with O and C atoms in mixed SiCO units. The PL spectrum of the SiCO nanowires showed strong and stable white emissions at 454 and 540 nm. A plasma-assisted vapor-solid growth mechanism is proposed to be responsible for the formation of the SiCO nanowires.
High Pressure Phase Stability of Ti with Self-consistent ab initio Lattice Dynamics Approach
Authors: Zeng Zhao-yi , Hu Cui-e , Liu Xun , Wei Zhang , Cai Ling-cang
Published: May 2015

The traditional quasiharmonic approximation cannot predict the phase diagram of Ti accurately, due to the well-known soften phonon modes of the β-Ti. By means of self-consistent ab initio lattice dynamics (SCAILD) method, in which the effects of phonon-phonon interactions are considered, the phonon dispersion relations at finite temperature for Ti are calculated. From the phonon dispersions, we extrapolat the acoustic velocities and harmonic elastic constants. The dynamical stable regions and phase diagram of Ti are also predicted successfully. The results show that SCAILD method can be designed to work for strongly anharmonic systems where the QHA fails.
Backlash in the London suburbs: the local-strategic tension in multilevel governance
Authors: Holman Nancy , Thornley Andy
Published: May 2015

In this paper we explore the tensions in metropolitan-level governance between strategic planning and desires for political decentralisation. We do this through a three-part analysis. First, we focus on the 2008 election strategy of Boris Johnson to become Mayor of London, with its aim of gaining suburban votes and giving more autonomy to the local borough level. We then look at the impacts of this campaign on electoral results; and, finally, we look at the outcome of the Outer London Commission, which was set up by the Mayor after the election to deal with strategic issues concerning London's suburbs. We find that a strategic intent to benefit suburban residents and the decentralisation of power to the boroughs are contradictory and have led to a policy stalemate.
Variation potential induces decreased PSI damage and increased PSII damage under high external temperatures in pea
Authors: Sukhov Vladimir , Surova Lyubov , Sherstneva Oksana , Bushueva Albina , Vodeneev Vladimir
Published: May 2015

Local burning of a leaf induces a unique electrical signal in plants: variation potential (VP), which can cause numerous functional responses, including changes in photosynthesis. The influences of VP on damage to photosynthetic machinery and thermal resistance of whole plant with heating were investigated in pea (Pisum sativum L.). Under high external temperature (53°C), VP induction was found to cause accelerated initial lowering of photosynthetic parameters, reduced transpiration rate, decreased PSI damage, and increased PSII damage. Increased PSI resistance was in good accordance with our previous data, but VP-induced stimulation of PSII damage under heating required further analysis. The magnitudes of leaf heating in experiments and controls were found to be different (~46−48°C after VP and ~44−45°C without it) under identical external temperatures and were connected with different transpiration rates under these conditions. Also PSII damage and the magnitude of leaf heating were strongly correlated. As a result, it was supposed that leaf temperature contributed to VP-induced stimulation of PSII damage with heating. Investigation of VP’s influence on pea growth after heating showed that the electrical signal decreased plant growth suppression after heating (i.e. VP-induced increases in PSII damage did not noticeably influence thermal resistance in the whole plant).
In vitro culture of stem-like cells derived from somatic cell nuclear transfer bovine embryos of the Korean beef cattle species, HanWoo
Authors: Kim Daehwan , Park Sangkyu , Jung Yeon-Gil , Roh Sangho
Published: May 2015

We established and maintained somatic cell nuclear transfer embryo-derived stem-like cells (SCNT-eSLCs) from the traditional Korean beef cattle species, HanWoo (Bos taurus coreanae). Each SCNT blastocyst was placed individually on a feeder layer with culture medium containing three inhibitors of differentiation (3i). Primary colonies formed after 2–3 days of culture and the intact colonies were passaged every 5–6 days. The cells in each colony showed embryonic stem cell-like morphologies with a distinct boundary and were positive to alkaline phosphatase staining. Immunofluorescence and reverse transcription–polymerase chain reaction analyses also confirmed that these colonies expressed pluripotent markers. The colonies were maintained over 50 passages for more than 270 days. The cells showed normal karyotypes consisting of 60 chromosomes at Passage 50. Embryoid bodies were formed by suspension culture to analyse in vitro differentiation capability. Marker genes representing the differentiation into three germ layers were expressed. Typical embryonal carcinoma was generated after injecting cells under the testis capsule of nude mice, suggesting that the cultured cells may also have the potential of in vivo differentiation. In conclusion, we generated eSLCs from SCNT bovine embryos, using a 3i system that sustained stemness, normal karyotype and pluripotency, which was confirmed by in vitro and in vivo differentiation.
Comparison of different fertilisation media for an in vitro maturation–fertilisation–culture system using flow-cytometrically sorted X chromosome-bearing spermatozoa for bovine embryo production
Authors: Ferré Luis B. , Bogliotti Yanina , Chitwood James L. , Fresno Cristóbal , Ortega Hugo H. , Kjelland Michael E. , Ross Pablo J.
Published: May 2015

High demand exists among commercial cattle producers for in vitro-derived bovine embryos fertilised with female sex-sorted spermatozoa from high-value breeding stock. The aim of this study was to evaluate three fertilisation media, namely M199, synthetic oviductal fluid (SOF) and Tyrode’s albumin–lactate–pyruvate (TALP), on IVF performance using female sex-sorted spermatozoa. In all, 1143, 1220 and 1041 cumulus–oocyte complexes were fertilised in M199, SOF and TALP, respectively. There were significant differences among fertilisation media (P < 0.05) in cleavage rate (M199 = 57%, SOF = 71% and TALP = 72%), blastocyst formation (M199 = 9%, SOF = 20% and TALP = 19%), proportion of Grade 1 blastocysts (M199 = 15%, SOF = 52% and TALP = 51%), proportion of Grade 3 blastocysts (M199 = 58%, SOF = 21% and TALP = 20%) and hatching rates (M199 = 29%, SOF = 60% and TALP = 65%). The inner cell mass (ICM) and trophectoderm (TE) cells of Day 7 blastocysts were also affected by the fertilisation medium. Embryos derived from SOF and TALP fertilisation media had higher numbers of ICM, TE and total cells than those fertilised in M199. In conclusion, fertilisation media affected cleavage rate, as well as subsequent embryo development, quality and hatching ability. SOF and TALP fertilisation media produced significantly more embryos of higher quality than M199.
Plasma and Kidney Angiotensin Peptides: Importance of the Aminopeptidase A/Angiotensin III Axis
Authors: Wysocki Jan , Ye Minghao , Batlle Daniel
Published: May 2015

BACKGROUND

The renin-angiotensin system is a complex regulatory hormonal network with a main biological peptide and therapeutic target, angiotensin (Ang) II (1–8). There are other potentially important Ang peptides that have not been well evaluated.

METHODS

Liquid chromatography–tandem mass spectrometry (LC-MS/MS) was used for concurrent evaluation of multiple Angs downstream of Ang I (1–10) and Ang II (1–8) in kidney and plasma from wild-type (WT) mice. Angiotensin converting enzyme 2 knockout (ACE2KO) was also used as a way to examine the Angs profile in the absence of ACE2, an enzyme that cleaves both Ang I (1–10) and Ang II (1–8).

RESULTS

In plasma from both WT and ACE2KO, levels of Ang I (1–10), Ang III (2–8), and Ang (2–10) were the highest of all the renin-angiotensin system (RAS) peptides. The latter two peptides are products of aminopeptidase A cleavage of Ang II (1–8) and Ang I (1–10), respectively. In contrast, plasma levels of Ang II (1–8), and Ang (1–7), the product of Ang II (1–8) cleavage by ACE2, were low. In kidney from both WT and ACE2KO, Ang II (1–8) levels were high as compared to plasma levels. In the ACE2KO mice, a significant increase in either Ang II (1–8) or a decrease in Ang (1–7) was not observed in plasma or in the kidney.

CONCLUSION

RAS-focused peptidomic approach revealed major differences in Ang peptides between mouse plasma and kidney. These Ang peptide profiles show the dominance of the aminopeptidase A/Ang (2–10) and aminopeptidase A/Ang III (2–8) pathways in the metabolism of Ang I (1–10) and Ang II (1–8) over the ACE2/Ang (1–7) axis. Ang III (2–8) and other peptides formed from aminopeptidase A cleavage may be important therapeutic RAS targets.
Measuring in situ krill tilt orientation by stereo photogrammetry: examples for Euphausia superba and Meganyctiphanes norvegica
Authors: Kubilius Rokas , Ona Egil , Calise Lucio
Published: May 2015

The natural body orientation adopted by krill is a crucial parameter for understanding and estimating the acoustic backscattering from these animals. Published data are scarce and are usually acquired with single camera systems that provide suboptimal control over the measurement accuracy. Here, we describe a stereo photo camera application for accurate krill measurements in situ, based on several Euphausia superba and Meganyctiphanes norvegica datasets. Body tilt orientation, body length, and school volume density from scattered and schooling krill are presented. Some challenges to the practical implementation of the method are discussed, including practical limits on krill body yaw angles for obtaining useful measurement accuracy and how to account accurately for the true vertical. Calibration and measurement accuracy is discussed together with a practical definition of krill body orientation. Krill sizes determined from stereo images are compared with those measured from trawl samples. The krill body tilt measurements yielded mean estimates of positive (head-up) or negative tilt of 9–17° with rather large spread for scattered aggregations of M. norvegica (SD = 30–37°) and about half of that for polarized schools of E. superba (SD = 14–17°). The measured krill body orientation distributions were also used to calculate krill acoustic target strength as predicted by the stochastic distorted wave Born approximation (SDWBA) model.
Two intertidal, non-calcifying macroalgae (Palmaria palmata and Saccharina latissima) show complex and variable responses to short-term CO2 acidification
Authors: Nunes Joana , McCoy Sophie J. , Findlay Helen S. , Hopkins Frances E. , Kitidis Vassilis , Queirós Ana M. , Rayner Lucy , Widdicombe Stephen
Published: May 2015

Ocean acidification, the result of increased dissolution of carbon dioxide (CO2) in seawater, is a leading subject of current research. The effects of acidification on non-calcifying macroalgae are, however, still unclear. The current study reports two 1-month studies using two different macroalgae, the red alga Palmaria palmata (Rhodophyta) and the kelp Saccharina latissima (Phaeophyta), exposed to control (pHNBS = ∼8.04) and increased (pHNBS = ∼7.82) levels of CO2-induced seawater acidification. The impacts of both increased acidification and time of exposure on net primary production (NPP), respiration (R), dimethylsulphoniopropionate (DMSP) concentrations, and algal growth have been assessed. In P. palmata, although NPP significantly increased during the testing period, it significantly decreased with acidification, whereas R showed a significant decrease with acidification only. S. latissima significantly increased NPP with acidification but not with time, and significantly increased R with both acidification and time, suggesting a concomitant increase in gross primary production. The DMSP concentrations of both species remained unchanged by either acidification or through time during the experimental period. In contrast, algal growth differed markedly between the two experiments, in that P. palmata showed very little growth throughout the experiment, while S. latissima showed substantial growth during the course of the study, with the latter showing a significant difference between the acidified and control treatments. These two experiments suggest that the study species used here were resistant to a short-term exposure to ocean acidification, with some of the differences seen between species possibly linked to different nutrient concentrations between the experiments.
Essential competencies in palliative medicine for neuro-oncologists
Authors: Thomas Alissa A. , Carver Alan
Published: May 2015

Palliative care is an approach to practicing medicine that addresses symptom management, alleviation of pain, assessment of psychosocial and spiritual distress or suffering, and practical support for patients and their caregivers with a goal of improving quality of life for patients with serious and life-threatening illnesses. Although palliative care has gained acceptance as an important part of comprehensive cancer care at the end of life, early integration of palliative care is less common. Patients with high-grade malignant gliomas have an invariably poor prognosis and high morbidity. With short survival times and complex neurological and systemic symptoms, these patients require palliative care from the time of diagnosis. In this review, we highlight the palliative care needs of neuro-oncology patients at diagnosis, during treatment, and at the end of life. We identify some of the barriers to incorporation of palliative care in standard neuro-oncology practice and equate competency in neuro-oncology with competency in the basic tenets of palliative medicine.
Antiretroviral Effects on Host Lipoproteins Are Associated With Changes in Hepatitis C Virus (HCV) RNA Levels in Human Immunodeficiency Virus/HCV Coinfected Individuals
Authors: Naggie Susanna , Patel Keyur , Yang Lan-Yan , Chow Shein-Chung , Johnson Victoria , Guyton John R. , Muir Andrew J. , Sulkowski Mark , Hicks Charles
Published: May 2015

We evaluated the impact of antiretroviral-induced dyslipidemia on hepatitis C virus (HCV) biogenesis in human immunodeficiency virus (HIV)/HCV coinfected patients. This study used serum samples from antiretroviral-naive HIV/HCV patients initiating their first regimen as part of AIDS Clinical Trials Group study protocols (A5142, A5202). Initiation of antiretrovirals increased most lipoproteins and apolipoproteins. In the multivariable model, changes in apolipoproteins were associated with changes in log10 HCV RNA from baseline to week-24 of therapy. Off-target lipogenic changes need to be considered in the context of liver and other metabolic disease in HIV/HCV patients.
Effect of Switching to Travoprost Preserved With SofZia in Glaucoma Patients With Chronic Superficial Punctate Keratitis While Receiving BAK-preserved Latanoprost
Authors: Aihara Makoto , Ikeda Yoko , Mizoue Shiro , Arakaki Yoshikuni , Kita Naofumi , Kobayashi Satoshi
Published: May 2015

Purpose:

To assess the effect of switching 1 eye to topical travoprost 0.004% preserved with SofZia (TRAVATAN Z solution) in patients who had chronic superficial punctate keratitis (SPK) in both eyes treated with benzalkonium chloride–preserved latanoprost 0.005% (XALATAN).

Methods:

This was a prospective, randomized, controlled, multicenter, open-label, comparative 3-month follow-up study. Patients with open-angle glaucoma or ocular hypertension who received XALATAN monotherapy for at least 3 months and had SPK in both eyes were enrolled at 9 facilities. For each patient, 1 eye was randomly selected and switched to TRAVATAN Z solution (T-group); the contralateral control eye was treated with XALATAN (X-group). SPK in 5 corneal regions, conjunctival hyperemia, tear breakup time (TBUT), and intraocular pressure (IOP) were examined in a masked manner at baseline, 1 month, and 3 months. Changes in SPK, hyperemia, TBUT, and IOP were compared within treatment groups and between treatment groups.

Results:

Fifty-six patients completed the study. The frequency of SPK significantly decreased from baseline in the T-group and the X-group at 1 and 3 months (T-group, P<0.001; X-group, P<0.05). In the T-group, SPK scores were significantly improved in 4 corneal regions, excluding the superior region, at 1 and 3 months (all P<0.05), whereas in the X-group, SPK scores were significantly improved only in the temporal region at 1 month and in the inferior region at 3 months (P<0.05 for both). The total SPK score at 1 and 3 months in the T-group was significantly lower compared with the score in the X-group (P=0.0023 and 0.0102, respectively). The SPK score for the superior and central corneal region at 3 months in the T-group was significantly lower compared with the score in the X-group (P=0.0212 and 0.022, respectively). There were no substantial intergroup or intragroup differences in changes from baseline for hyperemia scores, TBUT, or IOP reduction.

Conclusions:

Switching therapy from benzalkonium chloride–preserved latanoprost to travoprost preserved with SofZia ameliorated chronic SPK. There were no clinically relevant changes in hyperemia, TBUT, or IOP.
Superior abstract-concept learning by Clark's nutcrackers (
Nucifraga columbiana
)
Authors: Magnotti John F. , Katz Jeffrey S. , Wright Anthony A. , Kelly Debbie M.
Published: May 2015

The ability to learn abstract relational concepts is fundamental to higher level cognition. In contrast to item-specific concepts (e.g. pictures containing trees versus pictures containing cars), abstract relational concepts are not bound to particular stimulus features, but instead involve the relationship between stimuli and therefore may be extrapolated to novel stimuli. Previous research investigating the same/different abstract concept has suggested that primates might be specially adapted to extract relations among items and would require fewer exemplars of a rule to learn an abstract concept than non-primate species. We assessed abstract-concept learning in an avian species, Clark's nutcracker (
Nucifraga columbiana
), using a small number of exemplars (eight pairs of the
same
rule, and 56 pairs of the
different
rule) identical to that previously used to compare rhesus monkeys, capuchin monkeys and pigeons. Nutcrackers as a group (
N
= 9) showed more novel stimulus transfer than any previous species tested with this small number of exemplars. Two nutcrackers showed full concept learning and four more showed transfer considerably above chance performance, indicating partial concept learning. These results show that the Clark's nutcracker, a corvid species well known for its amazing feats of spatial memory, learns the same/different abstract concept better than any non-human species (including non-human primates) yet tested on this same task.
The molecular correlates of organ loss: the case of insect Malpighian tubules
Authors: Jing Xiangfeng , White Thomas A. , Yang Xiaowei , Douglas Angela E.
Published: May 2015

Malpighian tubules play an essential role in excretion, osmoregulation and immunity of most insects. Exceptionally, aphids lack Malpighian tubules, providing the opportunity to investigate the fate of genes expressed in an organ that has undergone evolutionary reduction and loss. Making use of the sequenced genomes of
Drosophila melanogaster
and the pea aphid
Acyrthosiphon pisum
, we demonstrated that more than 50% of
Drosophila
genes expressed specifically in the Malpighian tubules had orthologues in the pea aphid genome and that most of the pea aphid orthologues with detectable expression were identified in the gut transcriptome. Relative to the whole genome, genes functioning in amino acid metabolism are significantly over-represented among the pea aphid orthologues of Malpighian tubule genes, likely reflecting the central importance of amino acid acquisition and metabolism in aphids. This study demonstrates that the evolutionary loss of a key insect organ, the Malpighian tubules, has not been associated with the coupled loss of molecular functions.