bluuebunny/crossref_metadata_2025 huggingface dataset:
Forestation of boreal peatlands: Impacts of changing albedo and greenhouse gas fluxes on radiative forcing
Authors: Lohila Annalea , Minkkinen Kari , Laine Jukka , Savolainen Ilkka , Tuovinen Juha‐Pekka , Korhonen Lauri , Laurila Tuomas , Tietäväinen Hanna , Laaksonen Ari
Published: October 2010

We estimated the magnitude of the radiative forcing (RF) due to changes in albedo following the forestation of peatlands, and calculated the net RF by taking into account the changes in both the albedo and the greenhouse gas (GHG) fluxes during one forest rotation. Data on radiation, tree biomass, and soil GHG fluxes were combined with models for canopy cover, tree carbon accumulation, and the RF due to increased atmospheric GHG concentrations for four typical site cases in Finland covering two soil nutrient levels in the south and north of the country. We also studied the observed long‐term surface temperatures to detect any indications of drainage‐induced effects. The magnitude of the albedo‐induced RF was similar to that caused by the carbon sequestration of the growing trees. At three site cases out of four the drainage induced a cooling or negative RF, the tendency for cooling being higher at sites with a higher nutrient level. The differences in albedo‐induced RF mainly arose from the spring season due to (1) the different snow cover duration in the south versus the north, and (2) the different albedos of drained and undrained snow covered peatlands. An increase in the maximum daily temperatures was observed in April in southern Finland, where the most intensive drainage practices have taken place, suggesting that forestry drainage has potentially affected the local climate. Our results show that the decreasing albedo resulting from peatland forestation contributes significantly to the RF, balancing out or even exceeding the cooling effect due to the changing GHG fluxes.
Trichoplein/mitostatin regulates endoplasmic reticulum–mitochondria juxtaposition
Authors: Cerqua Cristina , Anesti Vassiliki , Pyakurel Aswin , Liu Dan , Naon Deborah , Wiche Gerhard , Baffa Raffaele , Dimmer Kai S , Scorrano Luca
Published: October 2010

Trichoplein/mitostatin (TpMs) is a keratin‐binding protein that partly colocalizes with mitochondria and is often downregulated in epithelial cancers, but its function remains unclear. In this study, we report that TpMs regulates the tethering between mitochondria and endoplasmic reticulum (ER) in a Mitofusin 2 (Mfn2)‐dependent manner. Subcellular fractionation and immunostaining show that TpMs is present at the interface between mitochondria and ER. The expression of TpMs leads to mitochondrial fragmentation and loosens tethering with ER, whereas its silencing has opposite effects. Functionally, the reduced tethering by TpMs inhibits apoptosis by Ca2+‐dependent stimuli that require ER–mitochondria juxtaposition. Biochemical and genetic evidence support a model in which TpMs requires Mfn2 to modulate mitochondrial shape and tethering. Thus, TpMs is a new regulator of mitochondria–ER juxtaposition.
The Influence of Emotional Intelligence on the Service Performance of Casino Frontline Employees
Authors: Prentice Catherine , King Brian
Published: October 2010

The concept of emotional intelligence (EI) has attracted substantial interest in the popular and organisational psychology literature. Although the predictive validity of EI is likely to depend on the context and focus of interest, researchers have identified a positive relationship between EI and job performance in the case of roles, which involve emotional labour, such as customer service. It offers the prospect of providing insights into job performance that have not been explained by traditional cognitive intelligence. This article explores the impact of EI on the service performance of frontline employees in the casino industry. The researchers test the hypothesis that EI is a predictor of the service performance of casino service representatives. A sample of 152 casino frontline employees in a large Australasia-based casino responded to a questionnaire-based survey, which considered EI, the five factors of personality and job performance. Based on multiple regression analysis, the results confirmed that EI is a significant predictor of the service performance of casino frontline employees for the high-roller market.
Toroidal charge exchange recombination spectroscopy measurements on MST
Authors: Magee R. M. , Den Hartog D. J. , Fiksel G. , Kumar S. T. A. , Craig D.
Published: October 2010

Charge exchange recombination spectroscopy measurements of the poloidal component of the C+6 temperature and flow in the Madison Symmetric Torus have been vital in advancing the understanding of the ion dynamics in the reversed field pinch. Recent work has expanded the diagnostic capability to include toroidal measurements. A new toroidal view overcomes a small signal-to-background ratio (5%–15%) to make the first localized measurements of the parallel component of the impurity ion temperature in the core of the reversed field pinch. The measurement is made possible through maximal light collection in the optical design and extensive atomic modeling in the fitting routine. An absolute calibration of the system allowed the effect of Poisson noise in the signal on line fitting to be quantified. The measurement is made by stimulating emission with a recently upgraded 50 keV hydrogen diagnostic neutral beam. Radial localization is ∼4 cm2, and good temporal resolution (100 μs) is achieved by making simultaneous emission and background measurements with a high-throughput double-grating spectrometer.
Optical measurements for turbulence characterization in RFX-mod edge
Authors: Agostini M. , Scarin P. , Cavazzana R. , Fassina A. , Alfier A. , Cervaro V.
Published: October 2010

The edge of the reversed field pinch experiment RFX-mod (R=2 m, a=0.46 m) is characterized by a complex magnetic topology and strong pressure gradients. A set of fast spectroscopic diagnostics has been designed to characterize both main plasma edge parameters and turbulence, including coherent structures (blobs) and radial profiles of the thermodynamic variables. Measurements of the edge radial profiles of electron density (ne), temperature (Te), and pressure (Pe) are obtained by a thermal helium beam diagnostic, which locally measures the ratios of the spectral lines emitted by a neutral He cloud puffed into hydrogen plasma discharges. A gas puff imaging system allows the high frequency (1 MHz bandwidth) measurement of the fluctuations of He I emissivity in the same positions. The system measures both the intermittent behavior of the edge turbulence and ne, Te, and Pe profiles of the corresponding coherent structures, with a resolution down to 6 μs. The optical diagnostics are complemented by a set of triaxial magnetic coils to simultaneously characterize the edge magnetic field.
Study of microscale hydraulic jump phenomenon for hydrodynamic trap-and-release of microparticles
Authors: Park Younggeun , Choi Yeonho , Mitra Debkishore , Kang Taewook , Lee Luke P.
Published: October 2010

Easy trap-and-release of microparticles is necessary to study biological cellular behavior. The hydraulic jump phenomenon inspired us to conceive a microfluidic device for the hydrodynamic trap-and-release of microparticles. A sudden height increase in a microfluidic channel leads to a dramatic decrease in flow velocity, allowing effective trapping of the microparticles by energy conversion. The trapped particles can be released by stronger inertial force based on simply increasing the flow velocity. We present a systematic, numerical study of trap-and-release of the microparticles using multiphase Navier–Stokes equations. Effect of geometry flow velocity, particle diameter, and adhesion force on trap-and-release was studied.
Design of dynamic Hohlraum opacity samples to increase measured sample density on Z
Authors: Nash T. J. , Rochau G. A. , Bailey J. E.
Published: October 2010

We are attempting to measure the transmission of iron on Z at plasma temperatures and densities relevant to the solar radiation and convection zone boundary. The opacity data published by us to date has been taken at an electron density about a factor of 10 below the 9×1022/cm3 electron density of this boundary. We present results of two-dimensional (2D) simulations of the heating and expansion of an opacity sample driven by the dynamic Hohlraum radiation source on Z. The aim of the simulations is to design foil samples that provide opacity data at increased density. The inputs or source terms for the simulations are spatially and temporally varying radiation temperatures with a Lambertian angular distribution. These temperature profiles were inferred on Z with on-axis time-resolved pinhole cameras, x-ray diodes, and bolometers. A typical sample is 0.3 μm of magnesium and 0.078 μm of iron sandwiched between 10 μm layers of plastic. The 2D LASNEX simulations indicate that to increase the density of the sample one should increase the thickness of the plastic backing.
A Pt–Ti–O gate Si-metal-insulator-semiconductor field-effect transistor hydrogen gas sensor
Authors: Usagawa Toshiyuki , Kikuchi Yota
Published: October 2010

A hydrogen gas sensor based on platinum–titanium–oxygen (Pt–Ti–O) gate silicon-metal-insulator-semiconductor field-effect transistors (Si-MISFETs) was developed. The sensor has a unique gate structure composed of titanium and oxygen accumulated around platinum grains on top of a novel mixed layer of nanocrystalline TiOx and superheavily oxygen-doped amorphous titanium formed on SiO2/Si substrates. The FET hydrogen sensor shows high reliability and high sensing amplitude (ΔVg) defined by the magnitude of the threshold voltage shift. ΔVg is well fitted by a linear function of the logarithm of air-diluted hydrogen concentration C (ppm), i.e., ΔVg(V)=0.355 log C(ppm)−0.610, between 100 ppm and 1%. This high gradient coefficient of ΔVg for the wide sensing range demonstrates that the sensor is suitable for most hydrogen-safety-monitoring sensor systems. The Pt–Ti–O structures of the sensor are typically realized by annealing Pt (15 nm)/Ti (5 nm)-gate Si-metal-oxide-semiconductor structures in air at 400 °C for 2 h. The Pt–Ti–O gate MIS structures were analyzed by transmission electron microscope (TEM), x-ray diffraction, Auger electron spectroscopy, and TEM energy dispersive x-ray spectroscopy. From the viewpoint of practical sensing applications, hydrogen postannealing of the Pt–Ti–O gate Si-MISFETs is necessary to reduce the residual sensing amplitudes with long tailing profiles.
Investigation of electronic configuration and plasmon loss spectra in Au-catalyzed silicon nanowire networks
Authors: Swain Bhabani S. , Swain Bibhu P. , Hwang Nong M.
Published: October 2010

The present study investigated the effect of a silane flow rate on chemical bonding structures of silicon nanowires (SiNWs) synthesized by atmospheric pressure chemical vapor deposition. The structural and chemical bonding structures were studied by Raman spectroscopy, Fourier transform infrared spectroscopy, and field emission scanning electron microscopy. The peak at 500 cm−1 in Raman spectra indicated the nanocrystalline SiNWs with outer matrix of a-Si/SiO2. X-ray photoelectron spectroscopy has been used to study the electronic structure and plasmon energy of SiNWs. The electronic environments of core orbital spectra of Si(2p) and O(1s) have been analyzed by the binding energy between constituent atoms. The plasmon spectra from different nanowires were estimated from curve fitting techniques with varying SiH4 flow rate. The peak at 17 eV is due to the Si plasmon in core SiNWs while the peak for interstitial Au appeared at ∼10 eV.
Integration of strained and relaxed silicon thin films on silicon wafers via engineered oxide heterostructures: Experiment and theory
Authors: Seifarth O. , Dietrich B. , Zaumseil P. , Giussani A. , Storck P. , Schroeder T.
Published: October 2010

Strained and relaxed single crystalline Si on insulator systems is an important materials science approach for future Si-based nanoelectronics. Layer transfer techniques are the dominating global integration approach over the whole wafer system but are difficult to scale down for local integration purposes limited to the area of the future device. In this respect, the heteroepitaxy approach by two simple subsequent epitaxial deposition steps of the oxide and the Si thin film is a promising way. We introduce tailored (Pr2O3)1−x(Y2O3)x oxide heterostructures on Si(111) as flexible heteroepitaxy concept for the integration of either strained or fully relaxed single crystalline Si thin films. Two different buffer concepts are explored by a combined experimental and theoretical study. First, the growth of fully relaxed single crystalline Si films is achieved by the growth of mixed PrYO3 insulators on Si(111) whose lattice constant is matched to Si. Second, isomorphic oxide-on-oxide epitaxy is exploited to grow strained Si films on lattice mismatched Y2O3/Pr2O3/Si(111) support systems. A thickness dependent multilayer model, based on Matthew’s approach for strain relaxation by misfit dislocations, is presented to describe the experimental data.
Peak effect of flux pinning in Sc5Ir4Si10 superconductors
Authors: Sun Y. , Shi Z. X. , Gu D. M. , Miura M. , Tamegai T.
Published: October 2010

Magnetic hysteresis loops (MHLs) have been comparatively measured on both textured and single crystalline Sc5Ir4Si10 superconductors. Critical current densities and flux pinning forces are calculated from MHLs by Bean model. Three kinds of peaks of the flux pinning force are found at low fields near zero, intermediated fields, and high fields near the upper critical field, respectively. The characters and origins of these peaks are studied in detail.
Screening of charged spheroidal colloidal particles
Authors: Álvarez Carlos , Téllez Gabriel
Published: October 2010

We study the effective screened electrostatic potential created by a spheroidal colloidal particle immersed in an electrolyte, within the mean field approximation, using Poisson–Boltzmann equation in its linear and nonlinear forms, and also beyond the mean field by means of Monte Carlo computer simulation. The anisotropic shape of the particle has a strong effect on the screened potential, even at large distances (compared to the Debye length) from it. To quantify this anisotropy effect, we focus our study on the dependence of the potential on the position of the observation point with respect with the orientation of the spheroidal particle. For several different boundary conditions (constant potential, or constant surface charge) we find that, at large distance, the potential is higher in the direction of the large axis of the spheroidal particle.
Particle motion between parallel walls: Hydrodynamics and simulation
Authors: Swan James W. , Brady John F.
Published: October 2010

The low-Reynolds-number motion of a single spherical particle between parallel walls is determined from the exact reflection of the velocity field generated by multipoles of the force density on the particle’s surface. A grand mobility tensor is constructed and couples these force multipoles to moments of the velocity field in the fluid surrounding the particle. Every element of the grand mobility tensor is a finite, ordered sum of inverse powers of the distance between the walls. These new expressions are used in a set of Stokesian dynamics simulations to calculate the translational and rotational velocities of a particle settling between parallel walls and the Brownian drift force on a particle diffusing between the walls. The Einstein correction to the Newtonian viscosity of a dilute suspension that accounts for the change in stress distribution due to the presence of the channel walls is determined. It is proposed how the method and results can be extended to computations involving many particles and periodic simulations of suspensions in confined geometries.
Nonparabolicity effects in InGaAs/GaAsSb double barrier resonant tunneling diodes
Authors: Silvano de Sousa J. , Detz H. , Klang P. , Nobile M. , Andrews A. M. , Schrenk W. , Gornik E. , Strasser G. , Smoliner J.
Published: October 2010

In this work, the electrons effective masses in double barrier resonant tunneling diodes fabricated on the InGaAs/GaAsSb material system are investigated by magnetotunneling experiments. It is found that due to the nonparabolic band structure in this material system, the electron effective masses increase significantly on samples with smaller well width and higher resonance energies. Surprisingly, a decreasing effective mass is observed with increasing Landau levels index. This mass decrease can be explained in terms of the quantum confined Stark effect influencing the resonant level positions inside the resonant tunneling diodes.
Performance of W4 theory for spectroscopic constants and electrical properties of small molecules
Authors: Karton Amir , Martin Jan M. L.
Published: October 2010

Accurate spectroscopic constants and electrical properties of small molecules are determined by means of W4 and post-W4 theories. For a set of 28 first- and second-row diatomic molecules for which very accurate experimental spectroscopic constants are available, W4 theory affords near-spectroscopic or better predictions. Specifically, the root-mean-square deviations (RMSDs) from experiment are 0.04 pm for the equilibrium bond distances (re), 1.03 cm−1 for the harmonic frequencies (ωe), 0.20 cm−1 for the first anharmonicity constants (ωexe), 0.10 cm−1 for the second anharmonicity constants (ωeye), and 0.001 cm−1 for the vibration-rotation coupling constants (αe). These RMSDs imply 95% confidence intervals of about 0.1 pm for re, 2.0 cm−1 for ωe, 0.4 cm−1 for ωexe, and 0.2 cm−1 for ωeye. We find that post-CCSD(T) contributions are essential to achieve such narrow confidence intervals for re and ωe, but have little effect on ωexe and αe, and virtually none on ωeye. Higher-order connected triples T̂3−(T) improve the agreement with experiment for the hydride systems, but their inclusion (in the absence of T̂4) tends to worsen the agreement with experiment for the nonhydride systems. Connected quadruple excitations T̂4 have significant and systematic effects on re, ωe, and ωexe, in particular they universally increase re (by up to 0.5 pm), universally reduce ωe (by up to 32 cm−1), and universally increase ωexe (by up to 1 cm−1). Connected quintuple excitations T̂5 are spectroscopically significant for ωe of the nonhydride systems, affecting ωe by up to 4 cm−1. Diagonal Born–Oppenheimer corrections have systematic and spectroscopically significant effects on re and ωe of the hydride systems, universally increasing re by 0.01–0.06 pm and decreasing ωe by 0.3–2.1 cm−1. Obtaining re and ωe of the pathologically multireference BN and BeO systems with near-spectroscopic accuracy requires large basis sets in the core-valence CCSD(T) step and augmented basis sets in the valence post-CCSD(T) steps in W4 theory. The triatomic molecules H2O, CO2, and O3 are also considered. The equilibrium geometries and harmonic frequencies (with the exception of the asymmetric stretch of O3) are obtained with near-spectroscopic accuracy at the W4 level. The asymmetric stretch of ozone represents a severe challenge to W4 theory, in particular the connected quadruple contribution converges very slowly with the basis set size. Finally, the importance of post-CCSD(T) correlation effects for electrical properties, namely, dipole moments (μ), polarizabilities (α), and first hyperpolarizabilities (β), is evaluated.
Graph approach to quantum systems
Authors: Pavičić Mladen , McKay Brendan D. , Megill Norman D. , Fresl Krešimir
Published: October 2010

Using a graph approach to quantum systems, we show that descriptions of 3-dim Kochen–Specker (KS) setups as well as descriptions of 3-dim spin systems by means of Greechie diagrams (a kind of lattice) that we find in the literature are wrong. Correct lattices generated by McKay-Megill-Pavicic (MMP) hypergraphs and Hilbert subspace equations are given. To enable future exhaustive generation of 3-dim KS setups by means of our recently found stripping technique, bipartite graph generation is used to provide us with lattices with equal numbers of elements and blocks (orthogonal triples of elements)—up to 41 of them. We obtain several new results on such lattices and hypergraphs, in particular, on properties such as superposition and orthoraguesian equations.
Metal-insulator transition characteristics of VO2 thin films grown on Ge(100) single crystals
Authors: Yang Z. , Ko C. , Ramanathan S.
Published: October 2010

Phase transitions exhibited by correlated oxides could be of potential relevance to the emerging field of oxide electronics. We report on the synthesis of high-quality VO2 thin films grown on single crystal Ge(100) substrates by physical vapor deposition and their metal-insulator transition (MIT) properties. Thermally triggered MIT is demonstrated with nearly three orders of magnitude resistance change across the MIT with transition temperatures of 67 °C (heating) and 61 °C (cooling). Voltage-triggered hysteretic MIT is observed at room temperature at threshold voltage of ∼2.1 V for ∼100 nm thickness VO2 films. Activation energies for electron transport in the insulating and conducting states are obtained from variable temperature resistance measurements. We further compare the properties of VO2 thin films grown under identical conditions on Si(100) single crystals. The VO2 thin films grown on Ge substrate show higher degree of crystallinity, slightly reduced compressive strain, larger resistance change across MIT compared to those grown on Si. Depth-dependent x-ray photoelectron spectroscopy measurements were performed to provide information on compositional variation trends in the two cases. These results suggest Ge could be a suitable substrate for further explorations of switching phenomena and devices for thin film functional oxides.
A comparative computational study of hydrogen and lithium-bonded complexes
Authors: McDowell Sean A. C. , Marcellin Rochelle C.
Published: October 2010

A computational study of hydrogen-bonded complexes of F3CH and C1H and of lithium-bonded complexes of F3CLi and CILi, with small molecules such as N2 and H2O was undertaken at the MP2/6-311++G(d,p) level of theory. Bond extensions and redshifts were obtained for the ClH bond in the ClH complexes, while bond contractions and blueshifts were obtained for the CH bond in the F3CH complexes. By contrast, bond extensions and blueshifts were obtained for all of the lithium-bonded species. These results were rationalized using a model derived from perturbation theory.
Photonic crystal slot nanobeam slow light waveguides for refractive index sensing
Authors: Wang Bowen , Dündar Mehmet A. , Nötzel Richard , Karouta Fouad , He Sailing , van der Heijden Rob W.
Published: October 2010

We present the design, fabrication, and photoluminescence experiment of InGaAsP photonic crystal slot nanobeam slow light waveguides with embedded InAs quantum dots. The strong confinement of electric field in the slot region is confirmed by the measured record high sensitivity of 7×102 nm per refractive index unit (RIU) to the refractive index change of the environment. A cavity, formed by locally deflecting the two beams toward each other, gives an even higher sensitivity of about 9×102 nm/RIU.
The susceptibility of α-helical secondary structure to steric strain: Coarse-grained simulation of dendronized polypeptides
Authors: Browne William , Geissler Phillip L.
Published: October 2010

The propensity of a peptide chain for adopting helical secondary structure can be modulated not only through the solvation properties of its side chains but also through their size and shape. Here we examine a coarse-grained model for dendronized polypeptides that focuses on the susceptibility of α-helical structure to the steric strain exerted by hydrophilic pendant groups. Undecorated molecules exhibit a pronounced transition from random coil to helix upon cooling [J. P. Kemp and J. Z. Y. Chen, Biomacromolecules 2, 389 (2001)]. As gauged by specific heat and by order parameters characterizing helicity at several length scales, this transition is quite robust to the introduction of first- and second-generation dendron side chains. More highly branched side chains, however, reduce the entropy of compact states so severely that helical ordering is undetectable over the entire temperature range accessible to our importance sampling methods. Consistent with experimental observations for side chains comparable to those of our model in volume-excluding size and shape, we find the backbone of these third-generation molecules to assume a distended rodlike state that is both stiff and achiral.
Highly temperature-stable modulation characteristics of multioxide-aperture high-speed 980 nm vertical cavity surface emitting lasers
Authors: Mutig A. , Lott J. A. , Blokhin S. A. , Wolf P. , Moser P. , Hofmann W. , Nadtochiy A. M. , Payusov A. , Bimberg D.
Published: October 2010

We present multioxide-aperture 980 nm-range vertical cavity surface emitting lasers (VCSELs) with highly temperature stable modulation characteristics operating error-free at 25 Gbit/s at 25 and 85 °C. We perform small signal modulation experiments and extract the fundamental physical parameters including relaxation resonance frequency, damping factor, parasitic cut-off frequency, D-factor, and K-factor, leading to identification of thermal processes and damping as the main factors that presently limit high speed device operation. We obtain very temperature-insensitive bandwidths around 13–15 GHz. Presented results clearly demonstrate the suitability of our VCSELs for practical and reliable optical data transmission systems.
Strain-driven phase transitions and associated dielectric/piezoelectric anomalies in BiFeO3 thin films
Authors: Huang C. W. , Chu Y. H. , Chen Z. H. , Wang Junling , Sritharan T. , He Q. , Ramesh R. , Chen Lang
Published: October 2010

Strain-driven phase transitions and related intrinsic polarization, dielectric, and piezoelectric properties for single-domain films were studied for BiFeO3 using phenomenological Landau–Devonshire theory. A stable and mixed structure between tetragonal and rhombohedral-like (monoclinic) phases is predicted at a compressive misfit strain of um=−0.0382 without an energy barrier. For a tensile misfit strain of um=0.0272, another phase transition between the monoclinic and orthorhombic phases was predicted with sharply high dielectric and piezoelectric responses.
Nonlocal viscosity of polymer melts approaching their glassy state
Authors: Puscasu R. M. , Todd B. D. , Daivis P. J. , Hansen J. S.
Published: October 2010

The nonlocal viscosity kernels of polymer melts have been determined by means of equilibrium molecular dynamics upon cooling toward the glass transition. Previous results for the temperature dependence of the self-diffusion coefficient and the value of the glass transition temperature are confirmed. We find that it is essential to include the attractive part of the interatomic potential in order to observe a strong glass transition. The width of the reciprocal space kernel decreases dramatically near the glass transition, being described by a deltalike function near and below the glass transition, leading to a very broad kernel in physical space. Thus, spatial nonlocality turns out to play an important role in polymeric fluids at temperatures near the glass transition temperature.
Coupled thermomechanics of single-wall carbon nanotubes
Authors: Scarpa F. , Boldrin L. , Peng H. X. , Remillat C. D. L. , Adhikari S.
Published: October 2010

The temperature-dependent transverse mechanical properties of single-walled nanotubes are studied using a molecular mechanics approach. The stretching and bond angle force constants describing the mechanical behavior of the sp2 bonds are resolved in the temperature range between 0 and 1600 K, allowing to identify a temperature dependence of the nanotubes wall thickness. We observe a decrease of the stiffness properties (axial and shear Young’s modulus) with increasing temperatures, and an augmentation of the transverse Poisson’s ratio, with magnitudes depending on the chirality of the nanotube. Our closed-form predictions compare well with existing molecular dynamics simulations.
Reduction of low-frequency 1/f noise in Al–AlOx–Al tunnel junctions by thermal annealing
Authors: Julin J. K. , Koppinen P. J. , Maasilta I. J.
Published: October 2010

We report that annealing Al–AlOx–Al tunnel junctions in a vacuum chamber at temperature of 400 °C reduces the characteristic 1/f noise in the junctions, in some cases by an order of magnitude. Both ultrahigh vacuum and high vacuum fabricated samples demonstrated a significant reduction in the 1/f noise level. Temperature dependence of the noise was studied between 4.2 and 340 K, with a linear dependence below 100 K, but a faster increase above. The results are consistent with a model where the density of charge trapping two level-systems within the tunneling barrier is reduced by the annealing process.
Electrical charging of Au nanoparticles embedded by streptavidin-biotin biomolecular binding in organic memory device
Authors: Jung Sung Mok , Kim Hyung-Jun , Kim Bong-Jin , Kim Yong-Sang , Yoon Tae-Sik , Lee Hyun Ho
Published: October 2010

In this study, electrical charging phenomena in an organic memory structure using Au nanoparticles (NPs) conjugated with a specific binding mechanism were demonstrated. Monolayer of streptavidin-passivated Au NPs was incorporated on biotin-coated SiO2 in structure of metal-pentacene-insulator-silicon (MPIS) device. Clockwise and counter-clockwise capacitance-voltage (C-V) hysteresis loops were measured depending on the oxide thickness. For 30 nm, a clockwise C-V hysteresis having memory window of 0.68 V was obtained under (+/−)12 V sweep range, while a counter-clockwise C-V hysteresis having memory window of 6.47 V was obtained under (+/−)7 V sweep range for 10 nm thick oxide.
Room-temperature photoresponse of Schottky photodiodes based on GaNxAs1−x synthesized by ion implantation and pulsed-laser melting
Authors: Yi Wei , Kim Taeseok , Shalish Ilan , Loncar Marko , Aziz Michael J. , Narayanamurti Venkatesh
Published: October 2010

The spectral responsivity for Schottky photodiodes based on the GaNxAs1−x alloys synthesized using nitrogen (N) ion implantation followed by pulsed-laser melting and rapid thermal annealing is presented. An N-induced redshift up to 250 meV (180 nm) in the photocurrent onset energy (wavelength) is observed. The N concentration dependence agrees with the values measured by photomodulated reflectance and ballistic electron emission microscopy, and with the calculation by the band anticrossing model for the splitting of the conduction band in GaNxAs1−x.
Revised Group Additivity Values for Enthalpies of Formation (at 298 K) of Carbon–Hydrogen and Carbon–Hydrogen–Oxygen Compounds
Authors: Cohen N.
Published: October 2010

A program has been undertaken for the evaluation and revision of group additivity values (GAVs) necessary for predicting, by means of Benson’s group additivity method, thermochemical properties of organic molecules. This review reports on the portion of that program dealing with GAVs for enthalpies of formation at 298.15 K (hereinafter abbreviated as 298 K) for carbon–hydrogen and carbon–hydrogen–oxygen compounds. A complete database of experimental data for gas, liquid, and crystal (solid) phase enthalpies of formation is presented. The GAVs, ring strain corrections, and non-nearest neighbor interactions derived from the database are presented in tabular form, together with a description of their evaluation and comments on reliability, uncertainties, and missing or questionable data.
The influence of goal-state access cost on planning during problem solving
Authors: Waldron Samuel M. , Patrick John , Duggan Geoffrey B.
Published: October 2010

Two problem-solving experiments investigated the relationship between planning and the cost of accessing goal-state information using the theoretical framework of the soft constraints hypothesis (Gray & Fu, 2004; Gray, Simms, Fu, & Schoelles, 2006). In Experiment 1, 36 participants were allocated to low, medium, and high access cost conditions and completed a problem-solving version of the Blocks World Task. Both the nature of planning (memory based or display based) and its timing (before or during action) changed with high goal-state access cost (a mouse movement and a 2.5-s delay). In this condition more planning before action was observed, with less planning during action, evidenced by longer first-move latencies, more moves per goal-state inspection, and more short (≤0.8 s) and long (>8 s) “preplanned” intermove latencies. Experiment 2 used an eight-puzzle-like transformation task and replicated the effect of goal-state access cost when more complex planning was required, also confirmed by sampled protocol data. Planning before an episode of move making increased with higher goal-state access cost, and planning whilst making moves increased with lower access cost. These novel results are discussed in the context of the soft constraints hypothesis.
The influence of expertise and of physical complexity on visual short-term memory consolidation
Authors: Sun Huiming , Zimmer Hubert D. , Fu Xiaolan
Published: October 2010

We investigated whether the expertise of a perceiver and the physical complexity of a stimulus influence consolidation of visual short-term memory (VSTM) in a S1–S2 (Stimulus 1–Stimulus 2) change detection task. Consolidation is assumed to make transient perceptual representations in VSTM more durable, and it is investigated by postexposure of a mask shortly after offset of the perceived stimulus (S1; 17 to 483 ms). We presented colours, Chinese characters, pseudocharacters, and novel symbols to novices (Germans) or experts of Chinese language (Chinese readers). Physical complexity was manipulated by the number of strokes. Unfamiliar material was remembered worse than familiar material (Experiments 1, 2, and 3). For novices the absolute VSTM performance was better for physically simple than for complex material, whereas for experts the complexity did not matter—Chinese readers memorized Chinese characters (Experiment 3). Articulatory suppression did not change these effects (Experiment 2). We always observed a strong effect of SOA, but this effect was influenced neither by physical complexity nor by expertise; only the length of the interstimulus interval between S1 and the mask was relevant. This was observed even with short stimulus onset asynchrony (SOA) of 100 ms (Experiment 2) and in comparing colours and characters (Experiment 5). However, masks impaired memory if they were presented at the locations of the to-be-memorized items, but not beside them—that is, interference was location-based (Experiment 6). We explain the effect of SOA by the assumption that it takes time to stop encoding of information presented at item locations with the offset of S1. The increasing resistance against interference by irrelevant material appears as consolidation of S1.
Impact of Crop Rotation and Bio-covers on Soybean Cyst Nematode
Authors: Wight Jason P. , Allen Fred L. , Donald Patricia A. , Tyler Don D. , Saxton Arnold M.
Published: October 2010

This research examined the effects of crop rotations and winter soil bio-covers on soybean cyst nematode (SCN) egg population density (EPD) under no-tillage. A field experiment with split-block treatments and four replications was conducted over three years with the whole-block treatments being rotations of corn (Zea mays L.), soybean [Glycine max (L.) Merr], and cotton (Gossypium hirsutum L.). Split-block treatments were bio-covers of winter wheat (Triticum aestivum L.), hairy vetch (Vicia villosa Roth), poultry litter, and fallow. Eggs were found in soybean-free sequences all four years, indicating potential residual viable SCN eggs in soil for seven years. Rotations with higher frequencies of soybean had significantly higher (P ≤ 0.01) SCN EPD than others, with continuous soybean being greatest. We did not observe a significant difference due to bio-cover on SCN EPD.

Accepted for publication 8 July 2011. Published 30 September 2011.
Growth of Pseudomonas putida F1 on styrene requires increased catechol-2,3-dioxygenase activity, not a new hydrolase
Authors: George Kevin W. , Kagle Jeanne , Junker Lauren , Risen Amy , Hay Anthony G.
Published: October 2010

Pseudomonas putidaF1 cannot grow on styrene despite being able to degrade it through the toluene degradation (tod) pathway. Previous work had suggested that this was because TodF, themeta-fission product (MFP) hydrolase, was unable to metabolize the styrene MFP 2-hydroxy-6-vinylhexa-2,4-dienoate. Here we demonstrate via kinetic and growth analyses that the substrate specificity of TodF is not the limiting factor preventing F1 from growing on styrene. Rather, we found that the metabolite 3-vinylcatechol accumulated during styrene metabolism and that micromolar concentrations of this intermediate inactivated TodE, the catechol-2,3-dioxygenase (C23O) responsible for its cleavage. Analysis of cells growing on styrene suggested that inactivation of TodE and the subsequent accumulation of 3-vinylcatechol resulted in toxicity and cell death. We found that simply overexpressing TodE on a plasmid (pTodE) was all that was necessary to allow F1 to grow on styrene. Similar results were also obtained by expressing a related C23O, DmpB fromPseudomonassp. CF600, in tandem with its plant-like ferredoxin, DmpQ (pDmpQB). Further analysis revealed that the ability of F1 (pDmpQB) and F1 (pTodE) to grow on styrene correlated with increased C23O activity as well as resistance of the enzyme to 3-vinylcatechol-mediated inactivation. Although TodE inactivation by 3-halocatechols has been studied before, to our knowledge, this is the first published report demonstrating inactivation by a 3-vinylcatechol. Given the ubiquity of catechol intermediates in aromatic hydrocarbon metabolism, our results further demonstrate the importance of C23O inactivation as a determinant of growth substrate specificity.
Characterization of T helper (Th)1‐ and Th2‐type immune responses caused by baculovirus‐expressed protein derived from the S2 domain of feline infectious peritonitis virus, and exploration of the Th1 and Th2 epitopes in a mouse model
Authors: Satoh Ryoichi , Kobayashi Hiroshige , Takano Tomomi , Motokawa Kenji , Kusuhara Hajime , Hohdatsu Tsutomu
Published: October 2010

Feline infectious peritonitis virus (FIPV) may cause a lethal infection in cats. Antibody‐dependent enhancement (ADE) of FIPV infection has been recognized, and cellular immunity is considered to play an important role in preventing the onset of feline infectious peritonitis. In the present study, whether or not the T helper (Th)1 epitope was present in the spike (S)2 domain was investigated, the ADE epitope being thought to be absent from this domain. Three kinds of protein derived from the C‐terminal S2 domain of S protein of the FIPV KU‐2 strain were developed using a baculovirus expression system. These expressed proteins were the pre‐coil region which is the N‐terminal side of the putative fusion protein (FP), the region from FP to the heptad repeat (HR)2 (FP‐HR2) region, and the inter‐helical region which is sandwiched between HR1 and HR2. The ability of three baculovirus‐expressed proteins to induce Th1‐ and Th2‐type immune responses was investigated in a mouse model. It was shown that FP‐HR2 protein induced marked Th1‐ and Th2‐type immune responses. Furthermore, 30 peptides derived from the FP‐HR2 region were synthesized. Five and 16 peptides which included the Th1 and Th2 epitopes, respectively, were identified. Of these, four peptides which included both Th1 and Th2 epitopes were identified. These findings suggest that the identification of Th1 epitopes in the S2 domain of FIPV has important implications in the cat.
Mechanisms of powdery mildew resistance in the Vitaceae family
Authors: FEECHAN ANGELA , KABBARA SAMUELA , DRY IAN B.
Published: October 2010

The cultivated grapevine, Vitis vinifera, is a member of the Vitaceae family, which comprises over 700 species in 14 genera. Vitis vinifera is highly susceptible to the powdery mildew pathogen Erysiphe necator. However, other species within the Vitaceae family have been reported to show resistance to this fungal pathogen, but little is known about the mechanistic basis of this resistance. Therefore, the frequency of successful E. necator penetration events, in addition to programmed cell death (PCD) responses, were investigated in a representative genotype from a range of different species within the Vitaceae family. The results revealed that penetration resistance and PCD‐associated responses, or combinations of both, are employed by the different Vitaceae genera to limit E. necator infection. In order to further characterize the cellular processes involved in the observed penetration resistance, specific inhibitors of the actin cytoskeleton and secretory/endocytic vesicle trafficking function were employed. These inhibitors were demonstrated to successfully break the penetration resistance in V. vinifera against the nonadapted powdery mildew E. cichoracearum. However, the use of these inhibitors with the adapted powdery mildew E. necator unexpectedly revealed that, although secretory and endocytic vesicle trafficking pathways play a crucial role in nonhost penetration resistance, the adapted powdery mildew species may actually require these pathways to successfully penetrate the plant host.
Characteristics of tumour vessels in cytological squash smears of astrocytic tumours
Authors: Sato S. , Sato Y. , Marutsuka K. , Takeshima H. , Asada Y.
Published: October 2010

S. Sato, Y. Sato, K. Marutsuka, H. Takeshima and Y. Asada

Characteristics of tumour vessels in cytological squash smears of astrocytic tumours

Objective:  Smear preparations are useful tools from which to diagnose brain tumours intraoperatively. Although vascular proliferation is histologically a key feature of high‐grade astrocytoma, the characteristics of tumour vessels in smear preparations have not been determined.

Methods:  We examined the density and morphological parameters (area, width, nuclear layer and branches of vessel wall) of tumour vessels in squash smears of 43 primary astrocytomas (grade II diffuse astrocytomas, n = 9; grade III anaplastic astrocytomas, n = 13; grade IV glioblastomas, n = 21) and normal brain tissues (n = 11).

Results:  Vessel density and all morphological parameters were significantly higher in grade IV than in the other grades of tumours and in normal brain tissue. Vessel area, width and nuclear layer were greater in grade III than in normal brain tissue. The sensitivity and specificity of these vessel parameters for astrocytomas were 75–100% and 82–100%, respectively.

Conclusions:  Tumour vessel evaluations from squash smears provide useful information for the intraoperative diagnosis and grading of astrocytic tumours.
Have jellyfish in the Irish Sea benefited from climate change and overfishing?
Authors: LYNAM C. P. , LILLEY M. K. S. , BASTIAN T. , DOYLE T. K. , BEGGS S. E. , HAYS G. C.
Published: October 2010

Climate change and overfishing may lead to ecosystem instability and may benefit nonexploited organisms such as jellyfish. In the Irish Sea, an increase in jellyfish abundance was evident (r2=0.29, P=0.03) in a 16‐year time‐series (1994–2009) collected during juvenile fish surveys. Jellyfish abundance correlated positively with sea surface temperature (SST) over the preceding 18 months (r=0.65, pACF<0.001) and copepod biomass in the previous year (r=0.56, pACF=0.03) and negatively with spring (February–May) precipitation (r=−0.57, pACF=0.02). Principal components regression indicated that climatic indices explained 68% of the interannual variability in jellyfish abundance (P=0.003), where the components were based on the North Atlantic Oscillation Index, SST and precipitation. The frequency of cnidarian material present in Continuous Plankton Recorder (CPR) samples has also increased since 1970, with a period of frequent outbreaks between 1982 and 1991. Before this period, the herring stock in the northern Irish Sea declined rapidly to a low level, potentially stimulating structural change in the ecosystem. In 1985, there was a step decrease in CPR copepod biomass and in 1989, a step increase in the phytoplankton colour index, suggesting a cascading regime shift during the 1980s. Subsequent overexploitation of gadids, coupled with warm temperatures and the poor recruitment of cod, led to the rapid decline in cod biomass from 1990. While the biomass of sprat has decreased in the last decade, the herring stock has recovered partially. Reductions in demersal fishing pressure since 2000, intended to stimulate cod recovery, appear to have facilitated further rises in haddock biomass. Since the 1980s regime shift, sea temperatures have increased, the fish community has altered and jellyfish abundance has risen such that jellyfish and haddock may now play an increasingly important role in the ecosystem.
Range‐wide population genetic structure of the European bitterling (Rhodeus amarus) based on microsatellite and mitochondrial DNA analysis
Authors: BRYJA J. , SMITH C. , KONEČNÝ A. , REICHARD M.
Published: October 2010

An understanding of recent evolutionary processes is essential for the successful conservation and management of contemporary populations, especially where they concern the introduction or invasion of species outside their natural range. However, the potentially negative implications of intraspecific introductions and invasions have attracted less attention, although they also represent a potential threat to biodiversity, and are commonly facilitated through human activities. The European bitterling (Rhodeus amarus) is a small cyprinid fish that decreased greatly in its distribution during the 1970s and 1980s and was subsequently included on many European conservation lists. This decline appears to have reversed, and the extent of its distribution now exceeds its former range. We used a combination of 12 microsatellite markers and cytochrome b sequences on a large data set (693 individuals) across the current range of the European bitterling to investigate possible scenarios for its colonization of Europe. We show that the inferred history of colonization of Europe was largely congruent between mitochondrial and nuclear markers. The most divergent mtDNA lineages occur in the Aegean region but probably are not reproductively isolated as the Aegean populations also displayed mtDNA haplotypes from other lineages and nuclear data indicated their close relationship to Danubian populations. Much of Europe is currently populated by descendants of two main lineages that came to natural secondary contact in western Europe. An approximate Bayesian computation analysis indicates different dates for admixture events among western and central European populations ranging from the last deglaciation (natural) to the last few centuries (human‐assisted translocations).