bluuebunny/crossref_metadata_2025 huggingface dataset:
Free carrier distribution profiling of 4H-SiC substrates using a commercial optical scanner
Authors: Caldwell Joshua D. , Glembocki Orest J. , Prokes Sharka M. , Glaser Evan R. , Hobart Karl D. , Hansen Darren M. , Chung Gilyong , Bolotnikov Alexander V. , Sudarshan Tangali S.
Published: May 2007

Presented here is an explanation for the use of a commercial optical scanner for the mapping of doping density (ND) within SiC substrates and as a local probe for ND variations. This method provides a fast and cost effective method for determining ND homogeneity, examining local electrical characteristics, and recognizing defect sites including areas of different polytypes or polycrystallinity. Hall effect and micro-Raman spectroscopy were used to calibrate the transmission amplitude, integrated area and scanner red, green, blue (RGB) luminance values with ND. It is shown that features presented in the calculated ND maps strongly correlate to those observed in Lehighton resistivity maps.
Anisotropic rotational diffusion and transient nonlinear responses of rigid macromolecules in a strong external electric field
Authors: Kalmykov Yuri P. , Titov Sergey V.
Published: May 2007

Nonlinear transient responses of polar polarizable particles (macromolecules) diluted in a nonpolar solvent to a sudden change in magnitude of a strong external dc field are evaluated using the anisotropic noninertial rotational diffusion model. The relaxation functions and relaxation times appropriate to the transient dynamic Kerr effect and nonlinear dielectric relaxation are calculated by solving the infinite hierarchy of differential-recurrence equations for statistical moments (ensemble averages of the Wigner D functions). The calculations involve matrix continued fractions, which ultimately yield the exact solution of the infinite hierarchy of differential-recurrence relations for the first- and second-order transient responses.
Shock wave structure in a lattice gas
Authors: Broadwell James E. , Han Donghee
Published: May 2007

The motion and structure of shock and expansion waves in a simple particle system, a lattice gas and cellular automaton, are determined in an exact computation. Shock wave solutions, also exact, of a continuum description, a model Boltzmann equation, are compared with the lattice results. The comparison demonstrates that, as proved by Caprino et al. [“A derivation of the Broadwell equation,” Commun. Math. Phys. 135, 443 (1991)] only when the lattice processes are stochastic is the model Boltzmann description accurate. In the strongest shock wave, the velocity distribution function is the bimodal function proposed by Mott-Smith.
Quantitative phase retrieval in transmission hard x-ray microscope
Authors: Yin Gung-Chian , Chen Fu-Rong , Hwu Yeukuang , Shieh Han-Ping D. , Liang Keng S.
Published: May 2007

Quantitative phase retrieval with a sub-100-nm resolution is achieved from micrographs of a zone plate based transmission x-ray microscope. A plastic zone plate containing objects of sizes from micrometers down to tens of nanometers is used as a test sample to quantify the retrieved phase. Utilizing the focal serial images in the image plane, the phase information is retrieved quantitatively across the entire range of sizes by combining the transport intensity equation and self-consistent wave propagation methods in this partial coherence system. The study demonstrates a solution to overcome the deficiency encountered in the two phase retrieval approaches.
Artificial fluid properties for large-eddy simulation of compressible turbulent mixing
Authors: Cook Andrew W.
Published: May 2007

An alternative methodology is described for large-eddy simulation (LES) of flows involving shocks, turbulence, and mixing. In lieu of filtering the governing equations, it is postulated that the large-scale behavior of a LES fluid, i.e., a fluid with artificial properties, will be similar to that of a real fluid, provided the artificial properties obey certain constraints. The artificial properties consist of modifications to the shear viscosity, bulk viscosity, thermal conductivity, and species diffusivity of a fluid. The modified transport coefficients are designed to damp out high wavenumber modes, close to the resolution limit, without corrupting lower modes. Requisite behavior of the artificial properties is discussed and results are shown for a variety of test problems, each designed to exercise different aspects of the models. When combined with a tenth-order compact scheme, the overall method exhibits excellent resolution characteristics for turbulent mixing, while capturing shocks and material interfaces in a crisp fashion.
Effective interaction parameter of linear/star polymer blends and comparison with that of linear/linear and star/star blends
Authors: Theodorakis P. E. , Avgeropoulos A. , Freire J. J. , Kosmas M. , Vlahos C.
Published: May 2007

The authors present a detailed study of the microscopic parameters, which control the miscibility in binary linear/star polymer blends. The effective interactions of linear/star polymer blends are studied by means of Monte Carlo simulations and comparison is made with linear/linear and star/star blends, which they also determined. Using the bond fluctuation model on a simple cubic lattice, the authors are able to simulate symmetric linear/linear, star/star, and, for the first time, linear/star blends with a moderate number of arms. The simulations were performed at a volume fraction of occupied lattice sites φ=0.5, which corresponds to dense polymer mixtures for this algorithm. In particular, we study star/star blends with 4, 8, and 12 arms and the respective linear/linear blends as well as linear/star blends, all having the same total number of units equal to 73 and 121. The authors find that linear/star blends are more miscible than the corresponding linear/linear blends, which is in agreement with recent experimental and theoretical results. They find that linear/star mixtures are less miscible than star/star blends, a result which is also verified by theoretical findings.
Effect of the continuity of the π conjugation on the conductance of ruthenium-octene-ruthenium molecular junctions
Authors: Ning Jing , Qian Zekan , Li Rui , Hou Shimin , Rocha A. R. , Sanvito S.
Published: May 2007

The conductance of a family of ruthenium-octene-ruthenium molecular junctions with different π conjugation are investigated using a fully self-consistent ab initio approach which combines the nonequilibrium Green’s function formalism with density functional theory. Our calculations demonstrate that the continuity of the π conjugation in the contact region as well as along the molecular backbone affects the junction conductance significantly, showing the advantage of using the ruthenium-carbon double bond as the linkage of conjugated organic molecules.
40% efficient metamorphic GaInP∕GaInAs∕Ge multijunction solar cells
Authors: King R. R. , Law D. C. , Edmondson K. M. , Fetzer C. M. , Kinsey G. S. , Yoon H. , Sherif R. A. , Karam N. H.
Published: May 2007

An efficiency of 40.7% was measured and independently confirmed for a metamorphic three-junction GaInP∕GaInAs∕Ge cell under the standard spectrum for terrestrial concentrator solar cells at 240 suns (24.0W∕cm2, AM1.5D, low aerosol optical depth, 25°C). This is the initial demonstration of a solar cell with over 40% efficiency, and is the highest solar conversion efficiency yet achieved for any type of photovoltaic device. Lattice-matched concentrator cells have now reached 40.1% efficiency. Electron-hole recombination mechanisms are analyzed in metamorphic GaxIn1−xAs and GaxIn1−xP materials, and fundamental power losses are quantified to identify paths to still higher efficiencies.
Development of a sum-over-states density functional theory for both electric and magnetic static response properties
Authors: Autschbach Jochen , Seth Michael , Ziegler Tom
Published: May 2007

It is shown that it is possible to formulate a sum-over-states (SOS) response theory for static perturbations based directly on the Kohn-Sham formulation of density functional theory (DFT). The SOS-DFT response theory affords expressions analogous to those obtained from the classical Raleigh-Schrödinger perturbation theory, where use is made of a complete set of ground and excited state energies and wave functions. The static SOS-DFT response theory is applicable for both real and imaginary perturbations. The theory is established by making use of time-dependent DFT taken to zero frequency with the use of the adiabatic approximation. In the SOS-DFT formulation the expression for electric (e.g., polarization) and magnetic (e.g., magnetization) response properties are symmetrical.
Effect of Mg content on structural, electrical, and optical properties of Li-doped Zn1−xMgxO thin films
Authors: Qiu M. X. , Ye Z. Z. , He H. P. , Zhang Y. Z. , Gu X. Q. , Zhu L. P. , Zhao B. H.
Published: May 2007

The authors have grown Li-doped p-type ZnMgO films on glass substrates with different Mg contents (11–28at.%) by pulsed laser deposition. Hall measurements suggest that the resistivity increases with Mg concentration. Acceptor levels related to LiZn located at about 150 and 174meV above the valence band maximum were discriminated in photoluminescence spectra for Li-doped Zn0.89Mg0.11O and Zn0.72Mg0.28O films, respectively. The conversion of donor-acceptor pair to a free-to-neutral-acceptor (e,A0) transition was also observed in Zn0.89Mg0.11O:Li film. The optical band gap and the acceptor binding energy increase with increase of Mg content in the films, which leads to reduction in the hole concentration and increase in the resistivity.
Direct quantitative tomographic reconstruction for weakly absorbing homogeneous phase objects
Authors: Arhatari B. D. , De Carlo F. , Peele A. G.
Published: May 2007

We examine a direct filtered back projection approach that is suitable for the reconstruction of weakly absorbing homogeneous phase objects. Like recent similar approaches this method needs only one intensity image in each projection without the requirement for an intermediate step of phase retrieval. We tested the method using simulation and experimental results. Simulation results show good quantitative reconstruction which includes the correct refractive index value and distribution of the sample. However, experimental result still indicates the presence of artifacts.
Enhanced responsivity in membrane isolated split-grating-gate plasmonic terahertz detectors
Authors: Shaner E. A. , Wanke M. C. , Grine A. D. , Lyo S. K. , Reno J. L. , Allen S. J.
Published: May 2007

A 50-fold increase in responsivity of plasmon resonant detectors is achieved by thermally isolating the detector on a thin membrane. Terahertz radiation is resonantly absorbed in the grating-gated channel while temperature modulation is sensed by the resistance of a narrow center region biased to pinch off. Thermal isolation enhances the temperature rise on absorption. Detectors with and without the additional thermal isolation demonstrate a linear power dependence.
Effects of carbon residue in atomic layer deposited HfO2 films on their time-dependent dielectric breakdown reliability
Authors: Cho Moonju , Kim Jeong Hwan , Hwang Cheol Seong , Ahn Hyo-Shin , Han Seungwu , Won Jeong Yeon
Published: May 2007

The effect of the carbon residue on the reliability of HfO2 thin films was investigated. HfO2 films were deposited on Si wafers by atomic layer deposition at a wafer temperature of 250°C using Hf[N(CH3)2]4 and O3 oxidant with two different densities (160 and 390g∕m3). The films deposited at the higher O3 density contained a lower concentration of carbon impurities. The leakage current density was lower and the time-dependent dielectric breakdown was improved in the higher O3 density films. First principles calculations confirmed that trap sites were generated in the band gap of HfO2 when carbon was interstitially or substitutionally present.
Femtosecond filamentation and supercontinuum generation in silver-nanoparticle-doped water
Authors: Wang Chen , Fu Yuxi , Zhou Zenghui , Cheng Ya , Xu Zhizhan
Published: May 2007

The authors report the investigation of filament and supercontinuum generation by focusing a femtosecond laser beam into water doped with silver nanoparticles. The silver nanoparticles enhance the nonlinear optical response of water, leading to broadening of supercontinuum spectra in self-focused femtosecond filaments. During the propagation of the supercontinuum light in the filament, the silver nanoparticles preferentially scatter the short-wavelength light near the plasmon resonant wavelength peak, followed by the scattering of the long-wavelength light. Thus, a side view of the filament shows a full-color spectrum in the visible range, which is herein called “rainbow filament.”
Improvement of reproducible hysteresis and resistive switching in metal-La0.7Ca0.3MnO3-metal heterostructures by oxygen annealing
Authors: Dong R. , Xiang W. F. , Lee D. S. , Oh S. J. , Seong D. J. , Heo S. H. , Choi H. J. , Kwon M. J. , Chang M. , Jo M. , Hasan M. , Hwang Hyunsang
Published: May 2007

Materials showing reversible resistance switching between high-resistance state and low-resistance state at room temperature are attractive for today’s semiconductor technology. In this letter, the improvement of reproducible hysteresis and resistive switching characteristics of metal-La0.7Ca0.3MnO3-metal (M-LCMO-M) heterostructures is demonstrated. The fabrication of the M-LCMO-M heterostructures is compatible with the standard complementary metal-oxide semiconductor process. The effect of oxygen annealing on the improvement of the hysteresis and resistive switching is discussed. The good retention characteristics are exhibited in the M-LCMO-M heterostructures by the accurate controlling of the preparation parameters.
Synthesis and nanoscale thermal encoding of phase-change nanowires
Authors: Sun Xuhui , Yu Bin , Meyyappan M.
Published: May 2007

Low-dimensional phase-change nanostructures provide a valuable research platform for understanding the phase-transition behavior and thermal properties at nanoscale and their potential in achieving superdense data storage. Ge2Sb2Te5 nanowires have been grown using a vapor-liquid-solid technique and shown to exhibit distinctive properties that may overcome the present data storage scaling barrier. Local heating of an individual nanowire with a focused electron beam was used to shape a nano-bar-code on a Ge2Sb2Te5 nanowire. The data encoding on Ge2Sb2Te5 nanowire may promote novel device concepts to implement ultrahigh density, low energy, high speed data storage using phase-change nanomaterials with diverse thermal-programing strategies.
Capacitively induced high mobility two-dimensional electron gas in undoped Si∕Si1−xGex heterostructures with atomic-layer-deposited dielectric
Authors: Lu T. M. , Liu J. , Kim J. , Lai K. , Tsui D. C. , Xie Y. H.
Published: May 2007

The authors demonstrate that a high mobility two-dimensional electron gas can be capacitively induced in an undoped Si∕Si1−xGex heterostructure using atomic-layer-deposited Al2O3 as the dielectric. The density is tuned up to 4.2×1011∕cm2, limited by the gate leakage current. The mobility increases with the density rapidly and reaches 5.5×104cm2∕Vs at the highest density. The observation of well developed quantum Hall states and two-dimensional metal-insulator transition shows that the devices are suitable for two-dimensional electron physics studies.
Real-time monitoring of organic vapor-phase deposition of molecular thin films using high-pressure reflection high-energy electron diffraction
Authors: Lunt Richard R. , Benziger Jay B. , Forrest Stephen R.
Published: May 2007

The crystalline thin film growth of the organic material, copper phthalocyanine (CuPc), by organic vapor-phase deposition (OVPD) is studied using high-pressure reflection high-energy electron diffraction (HP-RHEED). In situ growth of this material was monitored, in real time, on both highly oriented pyrolytic graphite and native SiO2 on Si(100) substrates. The growth of the first several monolayers on both substrates was found to be independent of the growth conditions; however, the crystalline texture of thicker films was controlled through changes in the substrate temperature and deposition rate. Higher substrate temperatures lead to an increase in crystalline ordering for growth on both substrates. This work shows that HP-RHEED is a powerful tool for real-time monitoring of growth morphology in the low-vacuum OVPD environment, ultimately leading to in situ control of thin film crystalline order.
Bridging domain mechanism for phase coexistence in morphotropic phase boundary ferroelectrics
Authors: Rao Wei-Feng , Wang Yu U.
Published: May 2007

Computer modeling and simulation reveals a bridging domain mechanism that explains the phase coexistence commonly observed around the morphotropic phase boundaries of ferroelectric solid solutions. The simulation takes into account the important role of coupled ferroelectric and ferroelastic domain microstructures in phase coexistence phenomenon. It shows that minor domains of metastable phase spontaneously coexist with and bridge major domains of stable phase to reduce total system free energy, including bulk free energy, domain wall energy, and long-range electrostatic and elastostatic energies. The existence of bridging domains also explains the enhanced piezoelectric response in the vicinity of morphotropic phase boundaries.
Low refractive index Si nanopillars on Si substrate
Authors: Lin Gong-Ru , Chang Ya-Chung , Liu En-Shao , Kuo Hao-Chung , Lin Huang-Shen
Published: May 2007

Low refractive index of a stalagmitelike high-aspect-ratio Si nanopillar array on Si dry etched using a self-aggregated Ni nanodot mask is demonstrated, which exhibits two minimum reflectances of 1.23 and 1.4 with corresponding refractive indices of 1.25 and 1.48 at 400 and 1200nm, respectively. Angular dependency of the transverse electrical mode reflectance at 632.8nm of the surface roughened Si nanopillar array is released, and the Brewster angle of 63° with equivalent refractive index of 1.5 is determined.
Thermal behavior of localized surface plasmon resonance of Au∕TiO2 core/shell nanoparticle arrays
Authors: Zheng Yue Bing , Huang Tony Jun , Desai Amit Yogesh , Wang Shi Jie , Tan Lee Kheng , Gao Han , Huan Alfred Cheng Hon
Published: May 2007

The authors investigate the thermal behavior of localized surface plasmon resonance (LSPR) of Au∕TiO2 core/shell nanoparticle arrays. Thermal annealing is carried out in three different routes, i.e., pre-TiO2 annealing, post-TiO2 annealing, and combinational annealing. It is found that the pre-TiO2 annealing causes a blueshift in LSPR, the combinational annealing results in a redshift, and the post-TiO2 annealing leads to an initial blueshift, followed by a redshift, and finally reverts to a blueshift. These resonance shifts correlate well with morphologic changes in Au cores and crystallization of TiO2 shells revealed by atomic force microscopy, x-ray diffraction, and x-ray photoemission spectroscopy.
Low-voltage and high-tunability interdigital capacitors employing lead zinc niobate thin films
Authors: Lee Young Chul , Hong Young Pyo , Ko Kyung Hyun
Published: May 2007

Employing high-tunability PbO–ZnO–Nb2O5 thin film dielectrics, low-voltage and high-tunability interdigital capacitors (IDCs) were implemented on a silicon substrate. In order to reduce the bias voltage of the IDC and increase its tunability, its electrodes were fully embedded into the thin film dielectrics to confine fringing electric fields within them. At 4V, the tunability of the IDCs was analyzed in terms of the electrode width and spacing by measuring reflection coefficients at 1GHz. The fabricated IDC with width and spacing of 1.5 and 1.8μm, respectively, achieved tunability of 26% and a Q factor of 10 at 5.5V.
Shape-induced ultraviolet absorption of CuO shuttlelike nanoparticles
Authors: Chen X. Y. , Cui H. , Liu P. , Yang G. W.
Published: May 2007

Homogeneous shuttlelike nanoparticles of CuO are synthesized using pulsed-laser induced liquid-solid interface reaction. The shape-induced ultraviolet absorption (258nm) is observed in the ultraviolet absorption spectrum of CuO shuttlelike nanoparticles. Theoretical calculations on the basis of discrete dipole approximation are employed to pursue the physical origin of the anomalous UV absorption peak. Both experiments and theories show that the shape of nanoparticles has a great influence on the optical properties.
Influence of vacancies on metallic nanotube transport properties
Authors: Neophytou Neophytos , Ahmed Shaikh , Klimeck Gerhard
Published: May 2007

The electronic behavior of metallic carbon nanotubes under the influence of atomistic vacancy defects present in the channel is theoretically investigated using non-equilibrium Green’s function method self-consistently coupled with three-dimensional electrostatics. A nearest neighbor tight binding model based on a single pz orbital is used for the device Hamiltonian. A single vacancy defect in the channel of a small diameter metallic carbon nanotube can decrease its conductance by a factor of 2. More than one vacancy in the channel can further drastically decrease the conductance. Larger diameter nanotubes suffer less from the presence of vacancy defects.
Smart optical microscanner with piezoelectric resonator, sensor, and tuner using Pb(Zr,Ti)O3 thin film
Authors: Kobayashi Takeshi , Maeda Ryutaro , Itoh Toshihiro , Sawada Renshi
Published: May 2007

The present study describes the design, fabrication, and demonstration of the optical microscanner with a piezoelectric resonator, sensor, and tuner: a smart optical microscanner. Pb(Zr,Ti)O3 thin film is deposited not only on the resonators but also on the hinges to act as the sensor or tuner. dc voltage applied to the tuner has shifted the resonant frequency and the sensor has successfully detected the shift of the resonant frequency. Though the frequency shift is only 1Hz∕V and the signal from the sensor is noisy, the results indicate the potential of the smart optical microscanner.
Magnetoelasticity of Tb0.3Dy0.7Fe1.95 alloys in a multiaxial stress-magnetic field space
Authors: Pei Yongmao , Fang Daining , Feng Xue
Published: May 2007

The simultaneous measurements of magnetization and magnetostriction have been carried out for Tb0.3Dy0.7Fe1.95 alloys subjected to the multiaxially magnetomechanical loading. The saturated magnetization and magnetostriction both decrease with the increase of the angle between the applied stress and magnetic filed. The magnetostriction goes up to a climax and then decreases as the applied magnetic field increases, which should remain saturated in the case of the specimen only subjected to the axial magnetic field. On the other hand, magnetization reaches saturation without any decrease in the same region of multiaxial magnetic-stress space. The unsaturated magnetostriction can be explained well by the magnetoelastic anisotropy. Such an investigation is important to validate theoretical approaches on the magnetomechanical behavior of giant magnetostrictive materials.
Automatization of nanotomography
Authors: Dietz C. , Röper S. , Scherdel S. , Bernstein A. , Rehse N. , Magerle R.
Published: May 2007

An approach for automated nanotomography, a layer-by-layer imaging technique based on scanning probe microscopy (SPM), is presented. Stepwise etching and imaging is done in situ in a liquid cell of an SPM. The flow of etching and rinsing solutions after each etching step is controlled with solenoid valves which allow for an automated measuring protocol. The thermal drift and the drift of the piezo scanner is corrected by applying offsets calculated from the cross correlation coefficients between successive images. As an example, we have imaged human bone with ∼10nm resolution using tapping mode SPM and successive etching with hydrochloric acid.
Incipient plasticity in metallic thin films
Authors: Soer W. A. , De Hosson J. Th. M. , Minor A. M. , Shan Z. , Syed Asif S. A. , Warren O. L.
Published: May 2007

The authors have compared the incipient plastic behaviors of Al and Al–Mg thin films during indentation under load control and displacement control. In Al–Mg, solute pinning limits the ability of dislocations to propagate into the crystal and thus substantially affects the appearance of plastic instabilities as compared to pure Al. Displacement control allows for a more sensitive detection of such instabilities, as it does not require collective dislocation motion to the extent required by load-controlled indentation in order to resolve a yield event. This perception is supported by in situ transmission electron microscopy observations.
Formation of Si clusters in AlGaN: A study of local structure
Authors: Somogyi A. , Martinez-Criado G. , Homs A. , Hernandez-Fenollosa M. A. , Vantelon D. , Ambacher O.
Published: May 2007

In this study, the authors report on the application of synchrotron radiation x-ray microprobe to the study of Si impurities in plasma-induced molecular beam epitaxy grown Al0.32Ga0.68N. Elemental maps obtained by μ-x-ray fluorescence spectrometry show inhomogeneous distributions of Si, Al, and Ga on the micron scale. X-ray absorption near-edge structure spectra taken at the Si and Al K edges provided information about their local chemical environment and revealed the change of the spectral features as depending on the position compared to the sample surface and on the concentration of Si.
Effects of strained InGaN interlayer on contact resistance between p-GaN and indium tin oxide
Authors: Lee Chi-Ling , Lee Wei-I
Published: May 2007

Indium tin oxide (ITO), with its transparency and strong adhesion to GaN, has been used as a replacement for Ni∕Au as a contact on p-GaN. However, ITO suffers from high contact resistance on p-GaN. In this work, low contact resistance between ITO and the p-GaN layer was consistently achieved using various strained InGaN layers as the interface layers between ITO and p-GaN layer. The doping of InGaN, whether n type or p type, has a relatively weak effect on the contact resistance as long as the thickness of the InGaN layer is adequately controlled. The secondary-ion-mass spectroscopy depth profile reveals that the n-type InGaN strained contact layer was also heavily doped with Mg. Results of this study demonstrate that the piezoelectric field between InGaN and p-GaN is important in reducing the barrier height of Ohmic contact.
Ferromagnetism in Ge nanostructures
Authors: Liou Y. , Su P. W. , Shen Y. L.
Published: May 2007

Room-temperature ferromagnetism was observed in Ge nanostructures deposited on polystyrene nanospheres. Various Ge layers (3, 5, 10, and 20nm) were deposited on different nanospheres (20, 30, 50, and 100nm in diameter). The magnetization in Ge nanostructures was influenced by both the thickness of Ge layers and the size of nanospheres. Maximum magnetization (360emu∕g) and magnetic moment (4.7μB∕Ge) were observed in the sample with a 5nm thick Ge layer on nanospheres with a diameter of 20nm. The ferromagnetism in Ge nanostructures was attributed to both the quantum size effect and the junctions among nanostructures.
Area-Specific Attentional Effect in the Delboeuf Illusion
Authors: Kawahara Jun-Ichiro , Nabeta Tomohiro , Hamada Jiro
Published: May 2007

In the Delboeuf illusion, a circle judged initially has a weaker effect of size induction than a circle judged subsequently (the judgment-order effect). This effect has been attributed to differential allocation of visual attention (Hamada et al, 2002 Japanese Journal of Psychology73 58–63, in Japanese). To establish the influence of attention, in experiment 1 we examined whether the effect occurred mandatorily once the outer circle was attended to, or whether it was necessary to direct attention specifically to the size of the area of the outer circle. Observers trisected the circumference of the outer circle thus attending to the outer circle in terms of its circumference, but ignoring its area. The illusion was stronger when the inner-circle area estimation was followed by the outer-circle area estimation than when the inner-circle area estimation was followed by the trisection task. In experiment 2 this result was replicated by using diameter judgment, instead of the size of the area. These findings indicate that mere allocation of attention to the outer circle contour is not sufficient to produce the judgment-order effect. Rather, attention must be specific to the task-relevant dimension, in this instance the visual area, to be effective.
Increased Abundance of Proteins Involved in Phytosiderophore Production in Boron-Tolerant Barley
Authors: Patterson John , Ford Kris , Cassin Andrew , Natera Siria , Bacic Antony
Published: May 2007

Boron (B) phytotoxicity affects cereal-growing regions worldwide. Although B-tolerant barley (Hordeum vulgare) germplasm is available, molecules responsible for this tolerance mechanism have not been defined. We describe and use a new comparative proteomic technique, iTRAQ peptide tagging (iTRAQ), to compare the abundances of proteins from B-tolerant and -intolerant barley plants from a ‘Clipper’ × ‘Sahara’ doubled-haploid population selected on the basis of a presence or absence of two B-tolerance quantitative trait loci. iTRAQ was used to identify three enzymes involved in siderophore production (Iron Deficiency Sensitive2 [IDS2], IDS3, and a methylthio-ribose kinase) as being elevated in abundance in the B-tolerant plants. Following from this result, we report a potential link between iron, B, and the siderophore hydroxymugineic acid. We believe that this study highlights the potency of the iTRAQ approach to better understand mechanisms of abiotic stress tolerance in cereals, particularly when applied in conjunction with bulked segregant analysis.
Food anaphylaxis
Authors: Wang Julie , Sampson Hugh A.
Published: May 2007

Anaphylaxis is a life‐threatening allergic reaction, and food is one of the most common responsible allergens in the outpatient setting. The prevalence of food‐induced anaphylaxis has been steadily rising. Education regarding food allergen avoidance is crucial as most of the fatal reactions occurred in those with known food allergies. The lack of a consensus definition for anaphylaxis has made its diagnosis difficult. Symptoms affect multiple organ systems and include pruritus, urticaria, angioedema, vomiting, diarrhoea, abdominal cramps, respiratory difficulty, wheezing, hypotension, and shock. Prompt recognition of anaphylaxis is essential as delayed treatment has been associated with fatalities. Although epinephrine is accepted as the treatment of choice, timely administration does not always occur, partly due to a lack of awareness of the diagnostic criteria. Several novel tools are currently being investigated, which will potentially aid in the diagnosis and treatment of food‐induced anaphylaxis.
Lower airways inflammation in allergic rhinitics: a comparison with asthmatics and normal controls
Authors: Brown J. L. , Behndig A. F. , Sekerel B. E. , Pourazar J. , Blomberg A. , Kelly F. J. , Sandström T. , Frew A. J. , Wilson S. J.
Published: May 2007

Background
Allergic rhinitis (AR) and asthma represent a continuum of atopic disease. AR is believed to pre‐dispose an individual to asthma. Compared with asthmatics and normal controls, the inflammatory response in the lower airways of rhinitics is not fully elucidated. To test the hypothesis that the inflammatory response in the airways of subjects with AR is at a level intermediate between that in normal controls and asthmatics, we have characterized bronchial inflammation and cytokine mRNA levels in non‐asthmatic allergic rhinitics and compared it with subjects with allergic asthma and with normal controls.

Methods
Endobronchial mucosal biopsies were obtained at bronchoscopy from 14 allergic rhinitics, 16 asthmatics and 21 normal controls. Biopsies were embedded into glycol methacrylate resin for immunohistochemical analysis of cellular inflammation and snap frozen for semi‐quantitative PCR analysis of cytokine mRNA levels.

Results
Airway inflammation in rhinitic subjects was characterized by an increase in submucosal eosinophils, mast cells and the mRNA expression of TNF‐α, at an intermediate level between healthy and asthmatics. In addition, CD3+ and CD8+ lymphocytes in the epithelium, the endothelial expression of vascular adhesion molecule‐1 and IL‐1β mRNA were higher in the allergic rhinitics compared with both normal controls and asthmatics, whereas growth‐related oncogene α‐mRNA was decreased in AR compared with both healthy and asthmatics. Airway inflammation in the asthmatic group was characterized by higher numbers of eosinophils and mast cells, together with an increase in TNF‐α‐mRNA compared with both healthy and rhinitics. IFN‐γ mRNA was the highest in normal controls and lowest in the asthmatics.

Conclusions
In individuals with AR the present data suggest an intermediate state of airway inflammation between that observed in normal individuals and subjects with clinical asthma. It is also indicated that IFN‐γ production by CD8+ T lymphocytes could be protective against the development of airway hyperresponsiveness. Further work is needed to evaluate this hypothesis.
The association between infant feeding practices and subsequent atopy among children with a family history of asthma
Authors: Mihrshahi S. , Ampon R. , Webb K. , Almqvist C. , Kemp A. S. , Hector D. , Marks G. B. ,   for the CAPS Team
Published: May 2007

Background
Although longer duration of breastfeeding and later introduction of solid foods are both recommended for the prevention of asthma and allergic disease, evidence to support these recommendations is controversial.

Objective
To examine the relation between infant feeding practices and the risk of asthma and allergic disease at age 5 years.

Methods
A cohort of children with a family history of asthma in Sydney, Australia, was followed from birth to age 5 years. Data on infant feeding practices and on early manifestations of eczema were collected prospectively. The presence of eczema, asthma and atopy (positive allergen skin prick tests) were determined at age 5 years.

Results
In 516 children evaluated at age 5 years, there was no significant association between the duration of breastfeeding or timing of introduction of solid foods and protection against asthma or other allergic disease, after adjustment for confounding factors. However, breastfeeding for 6 months or more and introduction of solid foods after 3 months were both associated with an increased risk of atopy at age 5 years (P=0.02 and 0.01, respectively). There was no significant association between the presence of eczema at 4 weeks and at 3 months and continued breastfeeding beyond those times.

Conclusion
Longer duration of breastfeeding and later introduction of solid foods did not prevent the onset of asthma, eczema or atopy by age 5 years.
Interaction of maternal atopy, CTLA‐4 gene polymorphism and gender on antenatal immunoglobulin E production
Authors: Yang K. D. , Ou C.‐Y. , Hsu T.‐Y. , Chang J.‐C. , Chuang H. , Liu C.‐A. , Liang H.‐M. , Kuo H.‐C. , Chen R.‐F. , Huang E.‐Y.
Published: May 2007

Background
Genetic heritability and maternal atopy have been correlated to antenatal IgE production, but very few studies have studied gene–maternal atopy interaction on antenatal IgE production. This study investigated the interaction of CTLA‐4 polymorphism with prenatal factors on the elevation of cord blood IgE (CBIgE).

Methods
Pregnant women were antenatally recruited for collection of prenatal environmental factors by a questionnaire. Umbilical cord blood samples were collected for CBIgE detection by fluorescence‐linked enzyme assay and CTLA‐4 polymorphism measurement by restriction fragment length polymorphism.

Results
A total of 1104 pregnant women initially participated in this cohort study, and 898 of them completed cord blood collection. 21.4% of the newborns had elevation of CBIgE (0.5 kU/L). The CTLA‐4+49A allele (P=0.021), maternal atopy (P<0.001) and gender (P=0.034), but not the CTLA‐4+49G allele, −318C allele, −318T allele, parental smoking or paternal atopy, were significantly correlated with the CBIgE elevation in multivariate analysis. A dichotomous analysis of gene–maternal atopy interactions identified maternal atopy and CTLA‐4+49A allele had an additive effect on the CBIgE elevation, especially prominent in male newborns; and in the absence of maternal atopy, CTLA‐4+49GG genotype had a protective effect on CBIgE elevation in female newborns.

Conclusions
Maternal but not paternal atopy has significant impacts on CBIgE elevation depending on gender and CTLA‐4+49A/G polymorphism of newborns. Control of maternal atopy and modulation of CTLA‐4 expression in the prenatal stage may be a target for the early prevention of perinatal allergy sensitization.
Up‐regulation of CCL17, CCL22 and CCR4 in drug‐induced maculopapular exanthema
Authors: Tapia B. , Morel E. , Martín‐Díaz M.‐Á. , Díaz R. , Alves‐Ferreira J. , Rubio P. , Padial A. , Bellón T.
Published: May 2007

Background
Maculopapular exanthema has been reported to be the most frequently drug‐induced cutaneous reaction. Although T lymphocytes are involved in the pathomechanism of this disease, little is know about the recruitment of these cells to the skin.

Objective
The aim of this work is to study the role of the chemokines TARC/CCL17 and MDC/CCL22 in the lymphocyte trafficking to affected skin in drug‐induced exanthemas.

Methods
Real‐time PCR was performed to quantify gene expression levels of CCL17, CCL22 and their receptor CCR4 in lesional skin biopsies and in peripheral blood mononuclear cells from patients. CCL27 and CCL22 proteins were detected in the skin by immunochemistry. Protein expression of CCR4 was determined by flow cytometry in peripheral blood lymphocytes. Functional migration assays to CCL17 and CCL22 were assessed to compare the migratory responses of peripheral blood lymphocytes from patients and healthy subjects.

Results
CCL17 and CCL22 were up‐regulated in maculopapular exanthema‐affected skin. CCR4 mRNA levels and protein expression were increased in peripheral blood mononuclear cells during the acute phase of the disease. The increased expression of the receptor was consistent with a higher response of peripheral blood lymphocytes to CCL17 and CCL22 compared with the migratory response in healthy donors.

Conclusion
TARC/CCL17 and MDC/CCL22 might cooperate in attracting T lymphocytes to skin in drug‐induced maculopapular exanthemas.
Understanding the potential role of mobile phone‐based monitoring on asthma self‐management: qualitative study
Authors: Pinnock H. , Slack R. , Pagliari C. , Price D. , Sheikh A.
Published: May 2007

Background
National and international healthcare policy increasingly seeks technological solutions to the challenge of providing care for people with long‐term conditions. Novel technologies, however, have the potential to change the dynamics of disease monitoring and self‐management. We aimed to explore the opinions and concerns of people with asthma and primary care clinicians on the potential role of mobile phone monitoring technology (transmitting symptoms and peak flows, with immediate feedback of control and reminder of appropriate actions) in supporting asthma self‐management.

Methods
This qualitative study recruited 48 participants (34 adults and teenagers with asthma, 14 asthma nurses and doctors) from primary care in Lothian (Central Scotland) and Kent (South East England). Thirty‐nine participated in six focus groups, which included a demonstration of the technology; nine gave in‐depth interviews before and after a 4‐week trial of the technology.

Results
Participants considered that mobile phone‐based monitoring systems can facilitate guided self‐management although, paradoxically, may engender dependence on professional/technological support. In the early phases, as patients are learning to accept, understand and control their asthma, this support was seen as providing much‐needed confidence. During the maintenance phase, when self‐management predominates, patient and professionals were concerned that increased dependence may be unhelpful, although they appreciated that maintaining an on‐going record could facilitate consultations.

Conclusion
Mobile phone‐based monitoring systems have the potential to support guided self‐management by aiding transition from clinician‐supported early phases to effective self‐management during the maintenance phase. Continuing development, adoption and formal evaluation of these systems should take account of the insights provided by our data.
A proof‐of‐concept study to assess the putative dose response to topical corticosteroid in persistent allergic rhinitis using adenosine monophosphate challenge
Authors: Barnes M. L. , Menzies D. , Nair A. R. , Hopkinson P. J. , Lipworth B. J.
Published: May 2007

Introduction
The aim of this proof‐of‐concept study was to assess whether nasal adenosine monophosphate (AMP) challenge may be used to quantify dose response to topical fluticasone propionate (FP) in persistent allergic rhinitis (PER).

Methods
Eligible subjects with PER entered a randomized double‐blind crossover study of 2 weeks of intranasal FP at 100 μg or 400 μg daily, with a 2‐week placebo washout period before each randomized treatment. Measurements after each washout or treatment comprised: peak nasal inspiratory flow (PNIF) response to nasal AMP (the primary outcome), domiciliary PNIF, the mini rhinoconjunctivitis quality of life questionnaire (miniRQLQ), symptom scores, nasal nitric oxide levels and overnight urinary cortisol:creatinine ratios.

Results
Thirteen patients completed per protocol. Maximal PNIF response to AMP was attenuated 0.9% (95% confidence interval −7.1 to 9.0, P=NS) by FP 100 μg, and 12.9% (4.8–20.9, P=0.009) by FP 400 μg. The 400–100 μg difference was 12.0% U (2.6–21.3, P=0.049). None of the other outcomes were responsive enough to detect any significant treatment effects. The standardized response means to FP 400 μg were 81% for AMP challenge, 54% for domiciliary PNIF, 53% for miniRQLQ, 24% for symptom scores and 18% for nasal nitric oxide. No adrenal suppression was detected at either dose.

Conclusion
FP exhibited dose‐related suppression of nasal airway hyperresponsiveness to AMP challenge, but without associated detectable adrenal suppression at the higher dose. Moreover, the AMP response demonstrated the highest signal to noise ratio compared with other outcome measures in PER.
Number of allergens to be tested to assess allergenic sensitization in epidemiologic studies: results of the European Community Respiratory Health Survey I
Authors: Bousquet P.‐J. , Hooper R. , Kogevinas M. , Jarvis D. , Burney P.
Published: May 2007

Background
Many clinical and epidemiological studies have measured the prevalence of IgE sensitization using skin tests and/or serum‐specific IgE. Most of them have been done in only one country using a battery of selected allergens relevant to that country. In multi‐centre studies, the number of tested allergens is often limited by the cost. It is therefore difficult to compare prevalence of sensitized subjects between studies.

Objective
To define the number and the type of allergen that should be tested in order to characterize a person as sensitized.

Method
Subjects were selected from the European Community Respiratory Health Survey I. All subjects underwent skin prick tests to nine of the most common allergens. In addition, two local allergens were tested in some centres.

Result
Using nine allergens, 35.6% of the 11 355 subjects were sensitized. The prevalence of sensitization increased with the number of tested allergens. Seven allergens enabled the identification of almost all sensitized subjects, adding another one inducing, in most countries, an increase of prevalence under 0.5%. Adding one local allergen to the battery of tests increased the overall estimated prevalence by only 1%. This increase was not seen in Ireland and was less marked in the United Kingdom (0.3%) but was greater in France (2.6%), Australia (2.5%) and Belgium (1.9%).

Conclusion
Seven selected allergens (Dermatophagoides pteronyssinus, cat, grass, birch, olive pollen, Alternaria and Cladosporium) allow the identification of almost all sensitized subjects in epidemiologic studies. Inclusion of local allergen should be considered in a standard panel for international studies.
Clinical pharmacology of buprenorphine in healthy, lactating goats
Authors: INGVAST‐LARSSON C. , SVARTBERG K. , HYDBRING‐SANDBERG E. , BONDESSON U. , OLSSON K.
Published: May 2007

The pharmacokinetics and the effects of the opioid buprenorphine on behavior, cardiovascular parameters, plasma concentrations of cortisol and vasopressin were studied in the goat. After intravenous injection at a dosage of 0.02 mg/kg bw, the terminal half‐life was 73.8 ± 19.9 min (mean ± SD), the apparent volume of distribution 5.22 ± 1.01 L/kg, and total body clearance 79.1 ± 18.5 mL/min/kg. After intramuscular administration of buprenorphine at the same dosage, bioavailability was complete and clearance was 54.7 ± 16.6 mL/min/kg. Heart rate, blood pressure and concentrations of cortisol and vasopressin in plasma increased after drug administration. The goats became agitated and stopped ruminating. The effects were more pronounced the first time the animals received the drug, especially the influence on the hormone levels. The concentrations of cortisol and vasopressin in plasma remained unaffected after the second dose despite a wash‐out period of 3–6 weeks. Buprenorphine may be an unsuitable drug in goats because of the profound inhibition of rumination and the agitation it causes. The short half‐life of buprenorphine may limit its use if long‐term analgesia is required but be advantageous if a short acting drug is desirable.
Can Trade Help Poor People? The Role of Trade, Trade Policy and Market Access in Tanzania
Authors: Duygan Burcu , Bump Jesse B.
Published: May 2007

Many development economists prescribe trade as a poverty‐reducing formula. But how is this elixir supposed to work? This article contributes to the lively debate on this topic with household evidence from Tanzania — a poor country even within sub‐Saharan Africa, the poorest region. About 81% of the poor work in agriculture, which accounts for 88% of the export bundle. The article describes existing poverty and then evaluates the poverty‐reduction potential of trade, trade policy and market access. The article extends the analysis by simulating tariff changes and four switching scenarios that swap some poor households into trade‐related sectors, such as cash cropping or tourism, to project national poverty reductions of up to 5.6% and household income increases of up to 21.5%.
Market‐based Price‐risk Management for Coffee Producers
Authors: Mohan Sushil
Published: May 2007

Coffee is characterised by high levels of price fluctuation, which exposes producers to price risk. Its wide trading in international commodity futures markets offers scope for producers to manage the risk by hedging on these markets, the mechanism for which is based on the use of put options. This article uses historical data of actual put‐options contracts to estimate the costs of the mechanism, the benefits being inferred from field evidence. It emerges that the costs are relatively low and outweighed by the benefits for most producers. The article then looks at the operational feasibility of the mechanism for producers and compares it with other hedging mechanisms.
KIERKEGAARD ON TAKING AN OUTING TO DEER PARK
Authors: MORRIS T. F.
Published: May 2007

I offer an exegesis of a few pages of the Concluding Unscientific Postscript and explain how going to Deer Park religiously fits into the general structure of Kierkegaard's thought. Because desiring God requires passion, and passion requires energy, there is a limit to how long any individual person can maintain a continuous desire for God. Kierkegaard discusses how a person who is at that limit can maintain a less intense love of God as he allows himself to desire temporal things.