bluuebunny/crossref_metadata_2025 huggingface dataset:
Features in chemical kinetics. II. A self-emerging definition of slow manifolds
Authors: Nicolini Paolo , Frezzato Diego
Published: June 2013

In the preceding paper of this series (Part I [P. Nicolini and D. Frezzato, J. Chem. Phys. 138, 234101 (2013)]10.1063/1.4809592) we have unveiled some ubiquitous features encoded in the systems of polynomial differential equations normally applied in the description of homogeneous and isothermal chemical kinetics (mass-action law). Here we proceed by investigating a deeply related feature: the appearance of so-called slow manifolds (SMs) which are low-dimensional hyper-surfaces in the neighborhood of which the slow evolution of the reacting system occurs after an initial fast transient. Indeed a geometrical definition of SM, devoid of subjectivity, “naturally” follows in terms of a specific sub-dimensional domain embedded in the peculiar region of the concentrations phase-space that in Part I we termed as “attractiveness region.” Numerical inspections on simple low-dimensional model cases are presented, including the benchmark case of Davis and Skodje [J. Chem. Phys. 111, 859 (1999)]10.1063/1.479372 and the preliminary analysis of a simplified model mechanism of hydrogen combustion.
Effects of surface modification with reactive mesogen on the anchoring strength of liquid crystals
Authors: Moon Yeon-Kyu , Lee You-Jin , In Jo Soo , Kim Youngsik , Uk Heo Jeong , Baek Ji-Ho , Kang Sung-Gon , Yu Chang-Jae , Kim Jae-Hoon
Published: June 2013

We studied the effects of polymer chain ordering in the alignment layer and resulting molecular interactions on the surface anchoring energy by introducing a reactive mesogen (RM) coating to the alignment layer. Directionally polymerized RMs on the rubbed alignment layer decrease the steric repulsion and increase the electronic interaction with liquid crystal molecules, and, as a result, the surface anchoring energy is enhanced in both the out-of plane and in-plane directions. We also demonstrated that this enhanced surface anchoring energy can be used to improve the response time characteristics of liquid crystal displays.
Nonlinear dynamics of spherical particles in Poiseuille flow under creeping-flow condition
Authors: Reddig S. , Stark H.
Published: June 2013

We study the nonlinear dynamics of spherical colloids under the influence of a pressure driven flow at vanishing Reynolds number. The colloids are confined between two parallel planar walls with a distance comparable to the particle diameter and they interact hydrodynamically via the solvent. We show that the bounded Poiseuille flow gives rise to new classes of trajectories resulting in cross-streamline migration. Two particles moving on these new trajectories exhibit either bound or unbound states. In the first case they oscillate on closed trajectories in the center-of-mass frame. In the second case, they exhibit cross-swapping trajectories in addition to swapping trajectories which were already observed in unbounded or bounded linear shear flow. The different classes of trajectories occur depending on the initial positions of the two particles and their size. We present state diagrams in the lateral positions, where we categorize the trajectories and color code the oscillation frequencies of the bound states. Finally we discuss how the results on the two-particle system help to understand the stability of particle trains composed of several particles.
Thermodynamic scaling of dynamics in polymer melts: Predictions from the generalized entropy theory
Authors: Xu Wen-Sheng , Freed Karl F.
Published: June 2013

Many glass-forming fluids exhibit a remarkable thermodynamic scaling in which dynamic properties, such as the viscosity, the relaxation time, and the diffusion constant, can be described under different thermodynamic conditions in terms of a unique scaling function of the ratio ργ/T, where ρ is the density, T is the temperature, and γ is a material dependent constant. Interest in the scaling is also heightened because the exponent γ enters prominently into considerations of the relative contributions to the dynamics from pressure effects (e.g., activation barriers) vs. volume effects (e.g., free volume). Although this scaling is clearly of great practical use, a molecular understanding of the scaling remains elusive. Providing this molecular understanding would greatly enhance the utility of the empirically observed scaling in assisting the rational design of materials by describing how controllable molecular factors, such as monomer structures, interactions, flexibility, etc., influence the scaling exponent γ and, hence, the dynamics. Given the successes of the generalized entropy theory in elucidating the influence of molecular details on the universal properties of glass-forming polymers, this theory is extended here to investigate the thermodynamic scaling in polymer melts. The predictions of theory are in accord with the appearance of thermodynamic scaling for pressures not in excess of ∼50 MPa. (The failure at higher pressures arises due to inherent limitations of a lattice model.) In line with arguments relating the magnitude of γ to the steepness of the repulsive part of the intermolecular potential, the abrupt, square-well nature of the lattice model interactions lead, as expected, to much larger values of the scaling exponent. Nevertheless, the theory is employed to study how individual molecular parameters affect the scaling exponent in order to extract a molecular understanding of the information content contained in the exponent. The chain rigidity, cohesive energy, chain length, and the side group length are all found to significantly affect the magnitude of the scaling exponent, and the computed trends agree well with available experiments. The variations of γ with these molecular parameters are explained by establishing a correlation between the computed molecular dependence of the scaling exponent and the fragility. Thus, the efficiency of packing the polymers is established as the universal physical mechanism determining both the fragility and the scaling exponent γ.
Anomalous viscosity effect in the early stages of the ion-assisted adhesion/fusion event between lipid bilayers: A theoretical and computational study
Authors: Raudino Antonio , Marrink Siewert J. , Pannuzzo Martina
Published: June 2013

The effect of viscosity on the encounter rate of two interacting membranes was investigated by combining a non-equilibrium Fokker-Planck model together with extensive Molecular Dynamics (MD) calculations. The encounter probability and stabilization of transient contact points represent the preliminary steps toward short-range adhesion and fusion of lipid leaflets. To strengthen our analytical model, we used a Coarse Grained MD method to follow the behavior of two charged palmitoyl oleoyl phosphatidylglycerol membranes embedded in a electrolyte-containing box at different viscosity regimes. Solvent friction was modulated by varying the concentration of a neutral, water-soluble polymer, polyethylene glycol, while contact points were stabilized by divalent ions that form bridges among juxtaposed membranes. While a naïve picture foresees a monotonous decrease of the membranes encounter rate with solvent viscosity, both the analytical model and MD simulations show a complex behavior. Under particular conditions, the encounter rate could exhibit a maximum at a critical viscosity value or for a critical concentration of bridging ions. These results seem to be confirmed by experimental observations taken from the literature.
Stimulated Raman back scattering of extraordinary electromagnetic waves from periodically magnetized nanoparticle lattice
Authors: Chakhmachi A.
Published: June 2013

Stimulated Raman back scattering of extraordinary electromagnetic waves from the nanoparticle lattice is investigated in the presence of the static magnetic field. In the context of macroscopic theory, dispersion relation and growth rate of extraordinary mode for different values of static magnetic field and lattice parameters are derived and analyzed. It is found that when the static magnetic field is off, dispersion relation has two branches. These branches are related to the plasmonic and body wave branches of the plane polarized wave. Low frequency branch of the pump wave is not involved in the instability while the other branch is not stable, and the growth rate of Raman back scattered wave has one peak. If the electrons have cyclotron frequency by static magnetic field, dispersion has three branches. These branches are related to the plasmonic and body wave branches of left and right hand circularly polarized waves. In this situation, it is found that low frequency lower branch of the pump wave is stable while other branches are not stable, and the growth rate of Raman back scattered wave has three peaks. Numerical study of growth rate in various cyclotron frequencies shows that the growth rate increases and the instability band width decreases with increasing static magnetic field.
High-pressure Raman scattering study of defect chalcopyrite and defect stannite ZnGa2Se4
Authors: Vilaplana R. , Gomis O. , Pérez-González E. , Ortiz H. M. , Manjón F. J. , Rodríguez-Hernández P. , Muñoz A. , Alonso-Gutiérrez P. , Sanjuán M. L. , Ursaki V. V. , Tiginyanu I. M.
Published: June 2013

High-pressure Raman scattering measurements have been carried out in ZnGa2Se4 for both tetragonal defect chalcopyrite and defect stannite structures. Experimental results have been compared with theoretical lattice dynamics ab initio calculations and confirm that both phases exhibit different Raman-active phonons with slightly different pressure dependence. A pressure-induced phase transition to a Raman-inactive phase occurs for both phases; however, the sample with defect chalcopyrite structure requires slightly higher pressures than the sample with defect stannite structure to fully transform into the Raman-inactive phase. On downstroke, the Raman-inactive phase transforms into a phase that could be attributed to a disordered zincblende structure for both original phases; however, the sample with original defect chalcopyrite structure compressed just above 20 GPa, where the transformation to the Raman-inactive phase is not completed, returns on downstroke mainly to its original structure but shows a new peak that does not correspond to the defect chalcopyrite phase. The pressure dependence of the Raman spectra with this new peak and those of the disordered zincblende phase is also reported and discussed.
Ultrasonic near-field optical microscopy using a plasmonic nanofocusing probe
Authors: Ahn Phillip , Zhang Zhen , Sun Cheng , Balogun Oluwaseyi
Published: June 2013

Ultrasonic waves are sensitive to the elastic properties of solids and have been applied in a variety of nondestructive materials characterization and metrology applications. The spatial resolution of established ultrasound techniques is limited to the order of the ultrasound wavelength, which is insufficient for nanomechanical characterization and imaging of nanoscale aspects of a material microstructure. Here, we report of an ultrasonic near-field optical microscopy (UNOM) technique that enables local mapping of ultrasound with deep sub-optical wavelength spatial resolution. In this technique, ultrasonic waves generated by a pulsed laser are detected by a scanning near-field optical probe over a broad frequency bandwidth. The scanning probe features a plasmonic nano-focusing lens that concentrates light to a strongly localized focal spot at the tip of the probe. The plasmonic probe enhances the scattering of evanescent light at the probe-tip and enables reliable measurement of the dynamic motion of a vibrating surface. The measurements made by the UNOM are purely optical; therefore, it is independent of mechanical coupling between the probe and the sample, which is one of the limitations of force based scanning probe microscopy methods. The UNOM technique allows for spatially and temporally resolved optical measurements of ultrasound with greater penetration depth, and it combines the benefits of local sensitivity to elastic and optical properties. Experimental results are presented, which demonstrate the potential of the technique for local mapping of subsurface optical absorbers in a soft material with high spatial resolution.
Robust stabilization for a class of nonlinear systems via a single input control applicable to chaotic systems and its circuit implementation
Authors: Sun Yeong-Jeu , Wu Yu-Biaw , Wang Ching-Cheng
Published: June 2013

In this study, the concept of global exponential ε-stabilization is introduced and the robust stabilization for a class of nonlinear systems with single input is investigated. Based on Lyapunov-like Theorem with differential and integral inequalities, a feedback control is proposed to realize the global stabilization of such nonlinear systems with any pre-specified exponential convergence rate. The guaranteed exponential convergence rate can be also correctly estimated. This result can be straightforwardly applicable to some famous chaotic systems. Besides, it will be proven that a single and linear control, with lower dimensions than that of the states, can realize the global exponential stability of some famous chaotic systems. Finally, comparisons of our main results with recently published results as well as numerical examples with circuit realization are provided to show the effectiveness and superiority of the obtained results.
Scanning tunneling microscopy of hundred-nanometer thick Nafion polymer covered Pt and highly ordered pyrolytic graphite
Authors: Zhou Juanjuan , Zhou Xiangyang
Published: June 2013

The atom-scale structure and properties of the interface between polymer electrolyte and electronic conductor are of great interest for novel electrochemical power sources including fuel cell, lithium batteries, and supercapacitors. Scanning tunneling microscopy, a well-known tool for imaging electronically conducting surface, is used to investigate Nafion polymer electrolyte coated Pt or highly ordered pyrolytic graphite. Periodic atom-scale patterns at the interface between Nafion and highly ordered pyrolytic graphite are obtained. In addition, in situ, real-time visualization of the atom-scale interface structure is realized upon changing the electrochemical potential of the substrates. The results suggest that a highly convergent resonant tunneling electron wave can penetrate a thick (200-1000 nm) recast Nafion (polymer electrolyte) coating and reach the substrates. A theory based on electron resonant tunneling is established to explain this phenomenon. It is expected that this method can be applied for real-time atom-scale visualization of other polymer/conductor interfaces.
Indirect laser-induced breakdown of transparent thin gel layer for sensitive trace element detection
Authors: Xiu Junshan , Bai Xueshi , Negre Erwan , Motto-Ros Vincent , Yu Jin
Published: June 2013

Optical emissions from major and trace elements embodied in a transparent gel prepared from cooking oil were detected when the gel was spread in thin film on a metallic substrate and a plasma was induced on the substrate surface using nanosecond infrared pulsed laser. Such emissions are due to indirect breakdown of the coating layer. The generated plasma, a mixture of substances from the substrate, the layer, and the ambient gas, was characterized using emission spectroscopy. Temperature higher than 15 000 K determined in the plasma allows considering sensitive detection of trace elements in liquids, gels, biological samples, or thin films.
Tuning the charge carriers in epitaxial graphene on SiC(0001) from electron to hole via molecular doping with C60F48
Authors: Tadich A. , Edmonds M. T. , Ley L. , Fromm F. , Smets Y. , Mazej Z. , Riley J. , Pakes C. I. , Seyller Th. , Wanke M.
Published: June 2013

We demonstrate that the intrinsic electron doping of monolayer epitaxial graphene on SiC(0001) can be tuned in a controlled fashion to holes via molecular doping with the fluorinated fullerene C60F48. In situ angle-resolved photoemission is used to measure an upward shift of (0.6 ± 0.05) eV in the Dirac point from −0.43 eV to +0.17 eV relative to the Fermi level. The carrier density is observed to change from n ∼ (1 × 1013 ± 0.1 × 1013) cm−2 to p ∼ (2 × 1012 ± 1 × 1012) cm−2. We introduce a doping model employing Fermi-Dirac statistics which explicitly takes temperature and the highly correlated nature of molecular orbitals into account. The model describes the observed doping behaviour in our experiment and readily explains why net p-type doping was not achieved in a previous study [Coletti et al., Phys. Rev. B 81, 8 (2010)] which used tetrafluorotetra-cyanoquinodimethane (F4-TCNQ).
Electrically controlled reversible and hysteretic magnetic domain evolution in nickel film/Pb(Mg1/3Nb2/3)O3]0.68-[PbTiO3]0.32 (011) heterostructure
Authors: Hockel J. L. , Pollard S. D. , Wetzlar K. P. , Wu T. , Zhu Y. , Carman G. P.
Published: June 2013

We report direct Lorentz microscopy observations of electrically induced magnetic domain motion in a nickel film/Pb(Mg1/3Nb2/3)O3]0.68-[PbTiO3]0.32 (PMN-PT (011)) heterostructure. The 0.5 mm-thick PMN-PT substrate contains a 10 μm-wide, 60 nm-thick Ni/Pt electron-permeable observation region. Stress from the substrate creates magnetoelastic anisotropy of up to 4 kJ m−3 in the nickel film resulting in reversible magnetization rotation as well as non-reversible domain wall jumps (i.e., Barkhausen jumps). The observed magnetization of the film is directly related to the local strain gradient as computed by the finite element method, providing strong evidence of the effectiveness of the strain-mediated magnetoelectric approach for device applications.
Modeling and simulation of carbon nanotube-semiconductor heterojunction vertical field effect transistors
Authors: Chen Wenchao , Rinzler Andrew G. , Guo Jing
Published: June 2013

The scaling behavior of carbon nanotube (CNT)-organic semiconductor heterojunction enabled vertical field effect transistors are comprehensively examined by two-dimensional consistent device simulations. Tunneling current is modeled by introducing tunneling induced carrier generation into the current continuity equation. Modulation of both the CNT-semiconductor Shottky barrier height and thickness are examined. The tunneling current and thermionic current dominate at on-state and off-state, respectively. Barrier height modulation plays an important role and improves the on-off current ratio and sub-threshold swing considerably. Small diameter CNT is preferred for enhancing the gate control on the CNT-channel barrier height. Reducing the effective gate oxide thickness by either a thin oxide or a high-κ gate insulator gives improvement of device performance, but the former one works more efficiently. The channel length and CNT spacing should be carefully engineered due to the trade-off between device characteristics in the sub-threshold and above-threshold region.
A kinetic Monte Carlo model with improved charge injection model for the photocurrent characteristics of organic solar cells
Authors: Kipp Dylan , Ganesan Venkat
Published: June 2013

We develop a kinetic Monte Carlo model for photocurrent generation in organic solar cells that demonstrates improved agreement with experimental illuminated and dark current-voltage curves. In our model, we introduce a charge injection rate prefactor to correct for the electrode grid-size and electrode charge density biases apparent in the coarse-grained approximation of the electrode as a grid of single occupancy, charge-injecting reservoirs. We use the charge injection rate prefactor to control the portion of dark current attributed to each of four kinds of charge injection. By shifting the dark current between electrode-polymer pairs, we align the injection timescales and expand the applicability of the method to accommodate ohmic energy barriers. We consider the device characteristics of the ITO/PEDOT/PSS:PPDI:PBTT:Al system and demonstrate the manner in which our model captures the device charge densities unique to systems with small injection energy barriers. To elucidate the defining characteristics of our model, we first demonstrate the manner in which charge accumulation and band bending affect the shape and placement of the various current-voltage regimes. We then discuss the influence of various model parameters upon the current-voltage characteristics.
Critical phenomena and estimation of the spontaneous magnetization by a magnetic entropy analysis in Mn0.96Nb0.04CoGe alloy
Authors: Debnath J. C. , Strydom A. M. , Shamba P. , Wang J. L. , Dou S. X.
Published: June 2013

Magnetic and magnetocaloric properties of the alloy Mn0.96Nb0.04CoGe have been investigated. According to the mean-field theory prediction, the relationship between ΔSM ∝ (H/TC)2/3 has been confirmed in the temperature region near TC for that system. To investigate the nature of the magnetic phase transition, a detailed critical exponent study has been performed. The critical components, γ, β, and δ determined using the Kouvel-Fisher method, the modified Arrott plot, as well as the critical isotherm analysis agree well. Moreover, these critical exponents are confirmed by the Widom scaling law and the validity of the calculated critical exponents was also confirmed by the scaling theory. The values deduced for the critical exponents are close to the theoretical prediction of the mean-field model values, thus indicating that long range interactions dominate the critical behavior in the Mn0.96Nb0.04CoGe system. It is also speculated that the competition between the localized Mn-Mn magnetic interactions should be responsible for the critical behavior in this system. Moreover, an excellent agreement is found between the spontaneous magnetization determined from the entropy change (−ΔSM vs. M2) and the classical extrapolation from the Arrott curves (H/M vs. M2), thus confirming that the magnetic entropy change is a valid approach to estimate the spontaneous magnetization in this system.
Radiative cooling by light down conversion of InGaN light emitting diode bonded to a Si wafer
Authors: Malyutenko V. K. , Bogatyrenko V. V. , Malyutenko O. Yu.
Published: June 2013

Using the recently proposed process of radiative cooling by light down conversion, we demonstrate cooling of about 5 K for InGaN light emitting diode (39 mg thermal load) that is self-heated up to 450 K and bonded to a cooler, a 15 × 15 × 4 mm3 Si wafer pumped with an above bandgap excitation from a 1.09-μm diode laser. Cooling occurs due to the enhancement of thermal emission in an initially transparent Si wafer when the overall energy of multiple (about 20) below bandgap photons escaping the wafer exceeds the energy of the single pumped photon. The cooling efficiency amounts to 93%.
Electrons trajectories around a bubble regime in intense laser plasma interaction
Authors: Lu Ding , Zhao Xue-Yan , Xie Bai-Song , Ali Bake Muhammad , Sang Hai-Bo , Wu Hai-Cheng
Published: June 2013

Some typical electrons trajectories around a bubble regime in intense laser plasma interaction are investigated theoretically. By considering a modification of the fields and ellipsoid bubble shape due to the presence of residual electrons in the bubble regime, we study in detail the electrons nonlinear dynamics with or without laser pulse. To examine the electron dynamical behaviors, a set of typical electrons, which locate initially at the front of the bubble, on the transverse edge and at the bottom of the bubble respectively, are chosen for study. It is found that the range of trapped electrons in the case with laser pulse is a little narrower than that without laser pulse. The partial phase portraits for electrons around the bubble are presented numerically and their characteristic behaviors are discussed theoretically. Implication of our results on the high quality electron beam generation is also discussed briefly.
Ultrasensitive food toxin biosensor using frequency based signals of silicon oxide nanoporous structure
Authors: Ghosh H. , RoyChaudhuri C.
Published: June 2013

We report an electrochemically fabricated silicon oxide nanoporous structure for ultrasensitive detection of AfB1 in food by shift in peak frequency corresponding to maximum sensitivity. It has been observed that the impedance sensitivity changes from 19% to 40% (which is only twice) where as the peak frequency shifts from 500 Hz to 50 kHz, for a change in concentration from 1 fg/ml to 1 pg/ml. This has been attributed to the combined effect of the significant pore narrowing with increasing AfB1 concentration and the opposing nature of impedance change within the nanopores and the conducting substrate immediately below the nanoporous layer.
Effect of the thickness of BiFeO3 layers on the magnetic and electric properties of BiFeO3/La0.7Sr0.3MnO3 heterostructures
Authors: Wang Le , Wang Zhen , Jin Kui-juan , Li Jian-qi , Yang Huai-xin , Wang Can , Zhao Rui-qiang , Lu Hui-bin , Guo Hai-zhong , Yang Guo-zhen
Published: June 2013

BiFeO3 layers with various thicknesses were fabricated on La0.7Sr0.3MnO3 covered SrTiO3 substrates by a laser molecular-beam epitaxy system. The ferromagnetic transition temperature (Tc) and magnetic coercive field (Hc) of BiFeO3/La0.7Sr0.3MnO3 heterostructures are larger than those of the La0.7Sr0.3MnO3 film. With increasing the thickness of the BiFeO3 layer, Tc, Hc, and ferroelectric coercive field of the BiFeO3/La0.7Sr0.3MnO3 heterostructures decrease, while the dielectric permittivity, remanent polarization, and resistance ratio of the ON and OFF states increase. The variations of the magnetic and electric properties with the thickness could be due to the effects of the epitaxial strain and the interface layer.
Distinguishing spin pumping from spin rectification in a Pt/Py bilayer through angle dependent line shape analysis
Authors: Bai Lihui , Feng Z. , Hyde P. , Ding H. F. , Hu C.-M.
Published: June 2013

A pure spin current driven by spin pumping is converted to a DC voltage and detected electrically in a Py/Pt bilayer sample. This DC voltage mixes with a DC voltage produced through spin rectification. The ferromagnetic resonance line shape strongly depends on the microwave magnetic h field distribution. We have systematically studied the line shapes by changing the external magnetic field orientation in plane of a Pt/Py bilayer. A method is demonstrated which allows us to calculate the microwave h field vector distribution, and distinguish spin pumping from spin rectification.
Effect of sperm pretreatment with sodium hydroxide and dithiothreitol on the efficiency of bovine intracytoplasmic sperm injection
Authors: Arias M. E. , Sánchez R. , Risopatrón J. , Pérez L. , Felmer R.
Published: June 2013

The efficiency of intracytoplasmic sperm injection (ICSI) in bovines is lower than in other species due, in part, to a lack of optimal conditions for its implementation; this has hindered the achievement of high rates of embryonic development and the birth of live offspring. The aim of the present study was to evaluate the effects of pretreatment of bovine spermatozoa with NaOH and dithiothreitol (DTT) on the viability, plasma membrane integrity, DNA fragmentation and in vitro developmental potential of embryos generated by ICSI. Following pretreatment of spermatozoa with 5 mM DTT for 20 min and a low concentration of NaOH (1 mM for 60 min), there were fewer live and acrosome reacted spermatozoa (44% and 34%, respectively) than in the control group without treatment (82%). Spermatozoa subjected to higher alkali concentrations (10–50 mM) were mostly dead and reacted. However, pronuclear formation, cleavage, blastocyst rate and embryo quality did not differ between these pretreatment groups and the untreated control group. In conclusion, we have described, for the first time, the effects of NaOH treatment on bovine spermatozoa and subsequent in vitro embryonic development after ICSI, and have demonstrated that pretreatment of bovine spermatozoa with NaOH or DTT is not necessary for an appropriate in vitro embryo development in this species.
Regional variation in trophic ecology of adult female Australian sea lions inferred from stable isotopes in whiskers
Authors: Lowther A. D. , Harcourt R. G. , Goldsworthy S. D.
Published: June 2013

Context
The primary selective forces responsible for shaping life-history traits come from the physical and biological environment in which a species resides. Consequently, the limits of a species range may provide a useful measure of adaptive potential to environmental change. The proximity of foraging grounds to terrestrial nursing habitat constrains central-place foragers such as otariid seals in selecting breeding locations. The Australian sea lion (Neophoca cinerea) is an endangered otariid endemic to Australia, whose northern-range extent occurs at a temperate–tropical transition zone on the western coast of Western Australia (WA).

Aims
Currently, there is a complete absence of data on the foraging ecology of Australian sea lions in WA. We sought to address this critical knowledge gap and provide data on the foraging ecology of adult female Australian sea lions at three isolated breeding colonies in western WA.

Methods
We used stable-isotope ratios of carbon (δ13C) and nitrogen (δ15N) in the whiskers of pups as proxies to characterise feeding behaviour of 10–28% of all adult female Australian sea lions at each colony. We then compared these geographic data to (1) conspecifics at similar latitude in South Australia (SA) and (2) isotopic data collated from other studies on seabirds that inhabit the region, to place foraging behaviour of adult female Australian sea lions into context.

Key results
At the southernmost colonies in WA, individual animals were members of one of two distinct isotopic clusters that could be described by differences in δ15N and δ13C values. Individuals at the northernmost colony displayed δ15N values similar to those of seabirds in the same region. Across the study, isotope ratios of adult female Australian sea lions in western WA were between 3‰ and 5‰ lower than those observed at a colony at similar latitude in SA.

Conclusions
Gross differences in the physical oceanography between WA and SA may in part explain the differences in isotope ratios of individuals between the regions, with lower δ15N and δ13C values in WA probably reflecting the relatively depauperate conditions of the Leeuwin Current.

Implications
Potential regional differences in trophic structure should be considered when developing appropriate management plans for Australian sea lions and regional variation in the diet of Australian sea lion warrants further investigation.
On a pairing of Goldberg-Shahidi for even orthogonal groups
Authors: Li Wen-Wei
Published: June 2013

Let

π
⊗
σ

\pi \otimes \sigma

be a supercuspidal representation of

G
L

(
2
n
)
×

S
O

(
2
n
)

\mathrm {GL}(2n) \times \mathrm {SO}(2n)

over a

p
p

-adic field with

π
\pi

selfdual, where

S
O

(
2
n
)

\mathrm {SO}(2n)

stands for a quasisplit even special orthogonal group. In order to study its normalized parabolic induction to

S
O

(
6
n
)

\mathrm {SO}(6n)

, Goldberg and Shahidi defined a pairing

R
R

between the matrix coefficients of

π
\pi

and

σ
\sigma

which controls the residue of the standard intertwining operator. The elliptic part

R
ell

R_\text {ell}

of

R
R

is conjectured to be related to twisted endoscopic transfer. Based on Arthur’s endoscopic classification and Spallone’s improvement of Goldberg-Shahidi program, we will verify some of their predictions for general

n
n

, under the assumption that

π
\pi

does not come from

S
O

(
2
n
+
1
)

\mathrm {SO}(2n+1)

.
How the ESRF helps industry and how they help the ESRF
Authors: Malbet-Monaco Stéphanie , Leonard Gordon A. , Mitchell Edward P. , Gordon Elspeth J.
Published: June 2013

The ESRF has worked with, and provided services for, the pharmaceutical industry since the construction of its first protein crystallography beamline in the mid-1990s. In more recent times, industrial clients have benefited from a portfolio of beamlines which offer a wide range of functionality and beam characteristics, including tunability, microfocus and micro-aperture. Included in this portfolio is a small-angle X-ray scattering beamline dedicated to the study of biological molecules in solution. The high demands on throughput and efficiency made by the ESRF's industrial clients have been a major driving force in the evolution of the ESRF's macromolecular crystallography resources, which now include remote access, the automation of crystal screening and data collection, and a beamline database allowing sample tracking, experiment reporting and real-time at-a-distance monitoring of experiments. This paper describes the key features of the functionality put in place on the ESRF structural biology beamlines and outlines the major advantages of the interaction of the ESRF with the pharmaceutical industry.
Squeezing the most from every crystal: the fine details of data collection
Authors: Krojer Tobias , Pike Ashley C. W. , von Delft Frank
Published: June 2013

Modern synchrotron beamlines offer instrumentation of unprecedented quality, which in turn encourages increasingly marginal experiments, and for these, as much as ever, the ultimate success of data collection depends on the experience, but especially the care, of the experimenter. A representative set of difficult cases has been encountered at the Structural Genomics Consortium, a worldwide structural genomics initiative of which the Oxford site currently deposits three novel human structures per month. Achieving this target relies heavily on frequent visits to the Diamond Light Source, and the variety of crystal systems still demand customized data collection, diligent checks and careful planning of each experiment. Here, an overview is presented of the techniques and procedures that have been refined over the years and that are considered synchrotron best practice.
Collecting data in the home laboratory: evolution of X-ray sources, detectors and working practices
Authors: Skarzynski Tadeusz
Published: June 2013

While the majority of macromolecular X-ray data are currently collected using highly efficient beamlines at an ever-increasing number of synchrotrons, there is still a need for high-performance reliable systems for in-house experiments. In addition to crystal screening and optimization of data-collection parameters before a synchrotron trip, the home system allows the collection of data as soon as the crystals are produced to obtain the solution of novel structures, especially by the molecular-replacement method, and is invaluable in achieving the quick turnover that is often required for ligand-binding studies in the pharmaceutical industry. There has been a continuous evolution of X-ray sources, detectors and software developed for in-house use in recent years and a diverse range of tools for structural biology laboratories are available. An overview of the main directions of these developments and examples of specific solutions available to the macromolecular crystallography community are presented in this paper, showing that data collection `at home' is still an attractive proposition complementing the use of synchrotron beamlines.
X4‐tropic human immunodeficiency virus IIIB utilizes CXCR4 as coreceptor, as distinct from R5X4‐tropic viruses
Authors: Islam Salequl , Hoque Sheikh Ariful , Adnan Nihad , Tanaka Atsushi , Jinno‐Oue Atsushi , Hoshino Hiroo
Published: June 2013

Human immunodeficiency viruses initiate infections via CCR5 coreceptors and then change their tropism to C‐X‐C chemokine receptor type 4 (CXCR4), this change being associated with rapid disease progression. HIV‐1IIIB, a widely described pure X4‐tropic strain, is distinct from R5X4‐tropic viruses. In this study, the requirement for amino terminal regions (NTRs) of CXCR4 for entry of HIV‐1IIIB virus into host cells was examined and compared to that of R5X4‐tropic viruses. CXCR4 and its deletion mutant (CXCR4ΔNTR23; first 23 amino acids removed from NTR) were amplified to examine their coreceptor activities. NP‐2/CD4/CXCR4 and NP‐2/CD4/CXCR4ΔNTR23 cell lines were prepared accordingly. Indirect immune fluorescence assay (IFA), PCR, and reverse transcriptase (RT) activity were used to compare the process of infection of host cells by HIV‐1IIIB virus, one R5‐tropic and five other R5X4‐tropic viruses. All the R5X4‐tropic HIVs were found to utilize both CCR5 and CXCR4 but unable to use CXCR4ΔNTR23 as coreceptors. In contrast, X4‐tropic HIV‐1IIIB was found to preferentially infect through CXCR4ΔNTR23. Viral antigens in infected NP‐2/CD4/CXCR4ΔNTR23 cells were detected by IFA and confirmed by detection of proviral DNA and by performing RT assays on the spent cell‐supernatants. In dual tropic viruses, deletion of 23 amino acids from NTR abrogates the coreceptor activity of CXCR4. This observation demonstrates that NTR of CXCR4 have an obligatory coreceptor role for dual tropic viruses. However, HIV‐1IIIB may have different requirements for NTR than R5X4 viruses or may infect host cells independent of NTR of CXCR4.
Lipopolysaccharide accelerates collagen‐induced arthritis in association with rapid and continuous production of inflammatory mediators and anti‐type II collagen antibody
Authors: Tanaka Shinji , Toki Tadashi , Akimoto Toshihiko , Morishita Kaoru
Published: June 2013

Collagen‐induced arthritis (CIA) is an animal model for rheumatoid arthritis (RA). Lipopolysaccharide (LPS) is known to accelerate CIA; however, the pathogenetic mechanisms are not yet fully understood. In this study, type II collagen (CII)‐immunized mice were found to have marked increases in degree of expression of mRNA of inflammatory mediators such as tumor necrosis factor alpha (TNF‐α), interleukin (IL)‐1β, and macrophage inflammatory protein‐2 (MIP‐2) in their arthritic paws and of serum anti‐CII antibody concentration before the onset of arthritis induced by LPS injection. The gene expression was rapid and continuous after direct activation of nuclear factor κB. The amounts of mRNA of TNF‐α, IL‐1β, and MIP‐2, as well as of matrix metalloproteinases and the receptor activator of nuclear factor κB ligand, increased with the development of arthritis, correlated positively with clinical severity and corresponded with histopathological changes. Moreover, anti‐TNF‐α neutralizing antibody inhibited the development of LPS‐accelerated CIA and a single injection of recombinant mouse TNF‐α induced increases in anti‐CII antibody concentrations, suggesting TNF‐α may contribute to the development of arthritis by both initiation of inflammation and production of autoantibodies. These data suggest that exacerbation of RA by LPS is associated with rapid and continuous production of inflammatory mediators and autoantibodies.
FORUM: Sharing or sparing? How should we grow the world's cities?
Authors: Lin Brenda B. , Fuller Richard A.
Published: June 2013

There has long been a debate amongst conservation biologists about how agricultural land use should be distributed spatially. Advocates of land sparing argue that high‐intensity food production on small units of land will conserve more natural habitat than low‐intensity farming spread across larger areas. Others argue that less intensive production over a greater area of land will reduce the overall load of human stressors upon ecosystems.

Although agricultural and urban systems have traditionally been considered as different fields of research, there are strong parallels between the two landscapes in the patterns of their spatial configuration and the trade‐offs associated with their development. Continued and rapid urbanization, with associated losses in vegetation, highlights the need for a uniting spatial framework to assess the ecological impacts of urbanization. Here, we apply some of the thinking emerging from the agricultural land‐sparing debate to urbanization, review the similarities and differences between the two systems and set out a research agenda.

Intensification of urban systems to increase housing density leads to buildings being interspersed with small tracts of natural or semi‐natural habitat patches (e.g. forest patches, parks). Urban extensification, on the other hand, is characterized by sprawling suburbanization with less concentrated, more distributed green space, often predominantly in the form of backyard or streetscape vegetation. We argue that regional scale analyses are urgently needed to determine which of these patterns of urban growth has a lower overall impact on biodiversity and to explore the geographical and taxonomic variation in the most ecologically appropriate city layout.

Synthesis and applications. The spatial pattern of urban development will affect biodiversity conservation within and beyond a city's borders. We chart the early progress of empirical work on the land‐sparing debate in an urban context and suggest that to yield development patterns that minimize overall ecological impact, urban planners must work at the scale of at least the entire city rather than on a case‐by‐case basis.
Working alliance development in occupational therapy: A cross‐case analysis
Authors: Morrison Tricia L. , Smith J. David
Published: June 2013

Background

Despite reverence afforded the therapeutic relationship construct in occupational therapy, many occupational therapists feel ill equipped to use themselves therapeutically to enhance the relationship with their clients. Furthermore, although occupational therapists often link the strength of the therapeutic relationship to therapy outcomes, related occupational therapy specific research has been limited. According to the psychotherapy literature, the working alliance is one element of the therapeutic relationship which has in fact been linked to therapy outcomes.

Methods

A mixed‐methods, prospective, multiple case study approach was used to compare the experiences of the working alliance by both occupational therapists and clients across four therapeutic dyads.

Results

Several key elements were identified in this study's qualitative data as shaping the process of alliance development in occupational therapy including: the fostering of an interpersonal connection; the use of humour as therapeutic modality; an impetus to act that leads to functional enhancements; a shared sense of success and a positive feedback mechanism created through successfully attaining clearly delineated, client‐centred therapy goals.

Conclusions

By considering these identified elements, occupational therapists may focus upon tangible considerations towards enhanced therapeutic use‐of‐self in the development of sound working alliance with their clients potentially improving therapy outcomes.
Correspondence between the Objective and Subjective Economies: The Role of Personal Economic Circumstances
Authors: Fraile Marta , Pardos-Prado Sergi
Published: June 2013

The impact of sociotropic economic satisfaction on the vote has been thoroughly analysed. However, knowledge about how citizens acquire information about the economy and the degree of correspondence between objective macroeconomic changes and citizens' subjective economic perceptions is much more limited. While the effect of partisan rationalisation has recently received some attention, the role of objective personal economic conditions in assessing national economic conditions is still unclear. We suggest that macroeconomic changes have some impact on subjective economic satisfaction, especially among higher-income and socio-professional strata with higher risk aversion rates to negative macroeconomic shocks. The results are obtained via three-level hierarchical linear models using the cumulative file of the European Social Survey (2002–9) and confirm the relevance of citizens' personal economic circumstances as a filter to perceive the state of the economy.
Structural Group Leadership and Regime Effectiveness
Authors: Grundig Frank , Ward Hugh
Published: June 2013

Usually the provision of international environmental public goods cannot be secured by a single state. Rather, a group of major powers has to pool its resources to provide structural leadership in order to achieve an effective regime. Such a group of pushers uses its structural power to achieve its goal. However, it faces two challenges. First, it may have to overcome the opposition of a group of laggards that desires less environmental protection and may try to counter the pushers' efforts. We hypothesise that the regime will be more effective to the extent to which the pushers predominate over the laggards in terms of structural power. Second, both groups may have to overcome a collective action problem with regard to dispensing costly side-payments. We argue that social capital embedded in inter-state networks may help the groups to overcome such collective action problems. Thus we argue that the regime will be more effective to the extent to which pushers are predominant and also have more social capital than laggards. Empirical results support our hypotheses.
U.S. Latina/o Muslims Since 1920: From “Moors” to “Latino Muslims”
Authors: Bowen Patrick D.
Published: June 2013

This article provides a historical overview of the development of the U.S. Latina/o Muslim community. U.S. Latina/os have been converting to Islam since the 1920s. Early converts were primarily found in African‐American‐majority Islamic communities, though there were some others who entered Islam through ties to Muslim immigrants. In both cases, the U.S.'s racist social system had brought the two communities together. In New York City during the 1970s, however, a group of around a dozen Latina/o Muslims felt that neither the African‐American‐majority nor the immigrant‐majority communities sufficiently addressed Latina/os' particular culture, languages, social situations, and contributions to Islamic history. To correct this, they created the first known U.S. Latina/o Muslim organisation, the Alianza Islamica, a group which fostered a “Latino Muslim” identity. Since that time, due to the growing numbers of U.S. Latina/o Muslims, as well as a tendency to foster ties with Latina/o Muslims in countries outside of the U.S., U.S. Latina/o Muslims are more and more adopting the “Latino Muslim” identity, which is now being promoted by several organisations and prominent leaders.
Undercover Acolytes: Honganji, the Japanese Army, and Intelligence‐Gathering Operations
Authors: Boyd James
Published: June 2013

In the late nineteenth and early twentieth century, as the Japanese Army sought intelligence on the countries neighbouring Japan, the military made use of the Buddhist priesthood as a cover for intelligence gathering. In addition, elements of the Buddhist priesthood, in particular the Kyoto‐based Honganji sect, were happy to cooperate with the military in its intelligence gathering operations, either by allowing military officers to disguise themselves as monks or by having Buddhist monks gather military intelligence for the Japanese Army. This article examines the relationship between the Japanese Army and the Honganji sect following the 1868 Meiji Restoration, the activities of military officers who disguised themselves as Buddhist monks and the intelligence gathering activities of Buddhist monks, hoping to shed more light on the part that Japanese Buddhism played in Japan's imperial adventures.