bluuebunny/crossref_metadata_2025 huggingface dataset:
A framework for design engineering education in a global context
Authors: Wodehouse Andrew J. , Grierson Hilary J. , Breslin Caroline , Eris Ozgur , Ion William J. , Leifer Larry J. , Mabogunje Ade
Published: July 2010

This paper presents a framework for teaching design engineering in a global context using innovative technologies to enable distributed teams to work together effectively across international and cultural boundaries. The Digital Libraries for Global Distributed Innovative Design, Education, and Teamwork (DIDET) Framework represents the findings of a 5-year project conducted by the University of Strathclyde, Stanford University, and Olin College that enhanced student learning opportunities by enabling them to partake in global, team-based design engineering projects, directly experiencing different cultural contexts and accessing a variety of digital information sources via a range of innovative technology. The use of innovative technology enabled the formalization of design knowledge within international student teams as did the methods that were developed for students to store, share, and reuse information. Coaching methods were used by teaching staff to support distributed teams and evaluation work on relevant classes was carried out regularly to allow ongoing improvement of learning and teaching and show improvements in student learning. Major findings of the 5-year project include the requirement to overcome technological, pedagogical, and cultural issues for successful eLearning implementations. The DIDET Framework encapsulates all the conclusions relating to design engineering in a global context. Each of the principles for effective distributed design learning is shown along with relevant findings and suggested metrics. The findings detailed in the paper were reached through a series of interventions in design engineering education at the collaborating institutions. Evaluation was carried out on an ongoing basis and fed back into project development, both on the pedagogical and the technological approaches.
Uncertain outcomes: adjusting for misclassification in antimalarial efficacy studies
Authors: PORTER K. A. , BURCH C. L. , POOLE C. , JULIANO J. J. , COLE S. R. , MESHNICK S. R.
Published: July 2010

Evaluation of antimalarial efficacy is difficult because recurrent parasitaemia can be due to recrudescence or re-infection. PCR is used to differentiate between recrudescences and re-infections by comparing parasite allelic variants before and after treatment. However, PCR-corrected results are susceptible to misclassification: false positives, due to re-infection by the same variant present in the patient before treatment; and false negatives, due to variants that are present but too infrequent to be detected in the pre-treatment PCR, but are then detectable post-treatment. This paper aimed to explore factors affecting the probability of false positives and proposes a Monte Carlo uncertainty analysis to account for both types of misclassification. Higher levels of transmission intensity, increased multiplicity of infection, and limited allelic variation resulted in more false recrudescences. The uncertainty analysis exploits characteristics of study data to minimize bias in the estimate of efficacy and can be applied to areas of different transmission intensity.
Rediscovery of the Honduran Emerald Amazilia luciae in western Honduras: insights on the distribution, ecology, and conservation of a ’Critically Endangered’ hummingbird
Authors: ANDERSON DAVID L. , HOUSE PAUL , HYMAN ROBERT E. , STEINER RICARDO , HAWKINS H. ROSS , THORN SHERRY , REY MANUEL J. , ESPINAL MARIO R. , MARINEROS LEONEL E.
Published: July 2010

The Honduran Emerald Amazilia luciae is endemic to dry forests of Honduras and currently recognised as ‘Critically Endangered.’ Here we present the first modern assessment of its distribution, ecology, and conservation, based partly on our rediscovery of the species in western Honduras and on our observations in three Honduran departments. We found that dry forests inhabited by the emerald differed in structure and species composition between eastern and western Honduras, where we observed emeralds in open-canopied deciduous thorn forests and closed-canopied semi-deciduous woodlands, respectively. We interpret these differences in light of the geological and anthropogenic origins of dry forests in Honduras, and discuss the implications of such origins for the conservation of dry forests. Although our findings expand the known distribution and population size of the species, its status as ‘Critically Endangered’ is warranted due to its restricted distribution in dry forest fragments and increasing human pressures on this habitat.
RAMSEY’S TEST, ADAMS’ THESIS, AND LEFT-NESTED CONDITIONALS
Authors: DIETZ RICHARD , DOUVEN IGOR
Published: July 2010

Adams famously suggested that the acceptability of any indicative conditional whose antecedent and consequent are both factive sentences amounts to the subjective conditional probability of the consequent given the antecedent. The received view has it that this thesis offers an adequate partial explication of Ramsey’s test, which characterizes graded acceptability for conditionals in terms of hypothetical updates on the antecedent. Some results in van Fraassen (1976) may raise hope that this explicatory approach to Ramsey’s test is extendible to left-nested conditionals, that is, conditionals whose antecedent is itself conditional in form. We argue that this interpretation of van Fraassen’s results is to be rejected. Specifically, we provide an argument from material inadequacy against a generalization of Adams’ thesis for left-nested conditionals.
Mantle structure beneath the western United States and its implications for convection processes
Authors: Xue Mei , Allen Richard M.
Published: July 2010

We present tomographic images of the mantle structure beneath the western United States. Our Dynamic North America Models of P and S velocity structure (DNA07‐P and DNA07‐S) use teleseismic body waves recorded at ∼600 seismic stations provided by the Earthscope Transportable Array and regional networks. DNA07‐P and ‐S benefit from the unprecedented aperture of the network while maintaining a dense station distribution providing high‐resolution body wave imaging of features through the transition zone and into the lower mantle. The main features imaged include (1) the Juan de Fuca subduction system that bottoms at ∼400 km beneath Oregon, implying interaction with the Yellowstone anomaly; (2) a low‐velocity conduit beneath Yellowstone National Park that bottoms at 500 km and dips toward the northwest; (3) shallow low‐velocity anomalies (upper 200 km) beneath the eastern Snake River Plain (ESRP) and the High Lava Plains, and a deep low‐velocity anomaly (>600 km) beneath the ESRP but not Newberry; (4) a low‐velocity “slab gap” to ∼400 km depth immediately south of the Mendocino Triple Junction and south of the Gorda slab; and (5) high‐velocity “drips” beneath the Transverse Ranges, the southern Central Valley/Sierra Nevada, and central Nevada. These observations reveal extremely heterogeneous mantle structure for the western United States and suggest that we are only just beginning to image the complex interactions between geologic objects. The transportable array allows for analysis of the relationships between these anomalies in an internally consistent single tomographic model. The DNA velocity models are available for download and slicing at http://dna.berkeley.edu.
Volcano monitoring using GPS: Developing data analysis strategies based on the June 2007 Kīlauea Volcano intrusion and eruption
Authors: Larson Kristine M. , Poland Michael , Miklius Asta
Published: July 2010

The global positioning system (GPS) is one of the most common techniques, and the current state of the art, used to monitor volcano deformation. In addition to slow (several centimeters per year) displacement rates, GPS can be used to study eruptions and intrusions that result in much larger (tens of centimeters over hours‐days) displacements. It is challenging to resolve precise positions using GPS at subdaily time intervals because of error sources such as multipath and atmospheric refraction. In this paper, the impact of errors due to multipath and atmospheric refraction at subdaily periods is examined using data from the GPS network on Kīlauea Volcano, Hawai'i. Methods for filtering position estimates to enhance precision are both simulated and tested on data collected during the June 2007 intrusion and eruption. Comparisons with tiltmeter records show that GPS instruments can precisely recover the timing of the activity.
Reply [to “Comments on ‘Base‐Flow Recessions—A Review’ by Francis R. Hall”]
Authors: Hall Francis R.
Published: July 2010

I appreciate receiving the comments by Dr. Snyder, and I agree that his method does allow separation of flow components on a time basis without any inference as to source. I do see a possible problem, however, in that the method requires the availability of considerable data as well as a fairly complex analysis. Therefore it is probably more suitable for well‐instrumented experimental watersheds than for ordinary gaged basins. Nevertheless this type of approach offers great potential, and I look forward to seeing the results of its application, particularly in conjunction with hydrogeologic studies.
On locally and nonlocally related potential systems
Authors: Cheviakov Alexei F. , Bluman George W.
Published: July 2010

For any partial differential equation (PDE) system, a local conservation law yields potential equations in terms of some potential variable, which normally is a nonlocal variable. The current paper examines situations when such a potential variable is a local variable, i.e., is a function of the independent and dependent variables of a given PDE system, and their derivatives. In the case of two independent variables, a simple necessary and sufficient condition is presented for the locality of such a potential variable, and this is illustrated by several examples. As a particular example, two-dimensional reductions of equilibrium equations for fluid and plasma dynamics are considered. It is shown that such reductions with respect to helical, axial, and translational symmetries have conservation laws which yield local potential variables. This leads to showing that the well-known Johnson–Frieman–Kruskal–Oberman (JFKO) and Bragg–Hawthorne (Grad–Shafranov) equations are locally related to the corresponding helically and axially symmetric PDE systems of fluid/plasma dynamics. For the axially symmetric case, local symmetry classifications and arising invariant solutions are compared for the original PDE system and the Bragg–Hawthorne (potential) equation. The potential equation is shown to have additional symmetries, denoted as restricted symmetries. Restricted symmetries leave invariant a family of solutions of a given PDE system but not the whole solution manifold, and hence are not symmetries of the given PDE system. Corresponding reductions are shown to yield solutions, which are not obtained as invariant solutions from local symmetry reduction.
O
2
reduction by lithium on Au(111) and Pt(111)
Authors: Xu Ye , Shelton William A.
Published: July 2010

Lithium-oxygen has one of the highest specific energies among known electrochemical couples and holds the promise of substantially boosting the specific energy of portable batteries. Mechanistic information of the oxygen reduction reaction by Li (Li-ORR) is scarce, and the factors limiting the discharge and charge efficiencies of the Li-oxygen cathode are not understood. To shed light on the fundamental surface chemistry of Li-ORR, we have performed periodic density functional theory calculations in conjunction with thermodynamic modeling for two metal surfaces, Au(111) and Pt(111). On clean Au(111) initial O2 reduction via superoxide (LiO2) formation has a low reversible potential of 1.51 V. On clean Pt(111), the dissociative adsorption of O2 is facile and the reduction of atomic O has a reversible potential of 1.97 V, whereas the associative channel involving LiO2 is limited by product stability versus O to 2.04 V. On both surfaces O2 lithiation significantly weakens the O–O bond, so the product selectivity of the Li-ORR is monoxide (LixO), not peroxide (LixO2). Furthermore, on both surfaces LixO species are energetically driven to form (LixO)n aggregates, and the interface between (LixO)n and the metal surfaces are active sites for forming and dissociating LiO2. Given that bulk Li2O(s) is found to be globally the most stable phase up to 2.59 V, the presence of available metal sites may allow the cathode to access the bulk Li2O phase across a wide range of potentials. During cycling, the discharge process (oxygen reduction) is expected to begin with the reduction of chemisorbed atomic O instead of gas-phase O2. On Au(111) this occurs at 2.42 V, whereas the greater stability of O on Pt(111) limits the reversible potential to 1.97 V. Therefore, the intrinsic reactivity of Pt(111) renders it less effective for Li-ORR than Au(111).
Self-clustering phenomenon of epitaxial FeSi nanoislands on Si(001)
Authors: Chen Shu-Fang , Chung Hung-Chin , Liu Chuan-Pu
Published: July 2010

This study investigates the evolution in the growth of FeSi nanoislands on Si(001). Under proper growth conditions, nanoislands spontaneously cluster into groups on rectangular FeSi terraces depending on both substrate temperature and deposition coverage. This study discussed the self-clustering mechanism in the context of strain relaxation and mass transportation between nanoislands and terraces.
Turbulence without Richardson–Kolmogorov cascade
Authors: Mazellier N. , Vassilicos J. C.
Published: July 2010

We investigate experimentally wind tunnel turbulence generated by multiscale/fractal grids pertaining to the same class of low-blockage space-filling fractal square grids. These grids are not active but nevertheless produce very much higher turbulence intensities u′/U and Reynolds numbers Reλ than higher blockage regular grids. Our hot wire anemometry confirms the existence of a protracted production region where turbulence intensity grows followed by a decay region where it decreases, as first reported by Hurst and Vassilicos [“Scalings and decay of fractal-generated turbulence,” Phys. Fluids 19, 035103 (2007)]. We introduce the wake-interaction length scale x⋆ and show that the peak of turbulence intensity demarcating these two regions along the centerline is positioned at about 0.5x⋆. The streamwise evolutions on the centerline of the streamwise mean flow and of various statistics of the streamwise fluctuating velocity all scale with x⋆. Mean flow and turbulence intensity profiles are inhomogeneous at streamwise distances from the fractal grid smaller than 0.5x⋆, but appear quite homogeneous beyond 0.5x⋆. The velocity fluctuations are highly non-Gaussian in the production region but approximately Gaussian in the decay region. Our results confirm the finding of Seoud and Vassilicos [“Dissipation and decay of fractal-generated turbulence,” Phys. Fluids 19, 105108 (2007)] that the ratio of the integral length-scale Lu to the Taylor microscale λ remains constant even though the Reynolds number Reλ decreases during turbulence decay in the region beyond 0.5x⋆. As a result, the scaling Lu/λ∼Reλ, which follows from the u′3/Lu scaling of the dissipation rate in boundary-free shear flows and in usual grid-generated turbulence, does not hold here. This extraordinary decoupling is consistent with a noncascading and instead self-preserving single-length scale type of decaying homogeneous turbulence proposed by George and Wang [“The exponential decay of homogeneous turbulence,” Phys. Fluids 21, 025108 (2009)], but we also show that Lu/λ is nevertheless an increasing function of the inlet Reynolds number Re0. Finally, we offer a detailed comparison of the main assumption and consequences of the George and Wang theory against our fractal-generated turbulence data.
A numerical test of a high-penetrability approximation for the one-dimensional penetrable-square-well model
Authors: Fantoni Riccardo , Giacometti Achille , Malijevský Alexandr , Santos Andrés
Published: July 2010

The one-dimensional penetrable-square-well fluid is studied using both analytical tools and specialized Monte Carlo simulations. The model consists of a penetrable core characterized by a finite repulsive energy combined with a short-range attractive well. This is a many-body one-dimensional problem, lacking an exact analytical solution, for which the usual van Hove theorem on the absence of phase transition does not apply. We determine a high-penetrability approximation complementing a similar low-penetrability approximation presented in previous work. This is shown to be equivalent to the usual Debye–Hückel theory for simple charged fluids for which the virial and energy routes are identical. The internal thermodynamic consistency with the compressibility route and the validity of the approximation in describing the radial distribution function is assessed by a comparison against numerical simulations. The Fisher–Widom line separating the oscillatory and monotonic large-distance behaviors of the radial distribution function is computed within the high-penetrability approximation and compared with the opposite regime, thus providing a strong indication of the location of the line in all possible regimes. The high-penetrability approximation predicts the existence of a critical point and a spinodal line, but this occurs outside the applicability domain of the theory. We investigate the possibility of a fluid-fluid transition by the Gibbs ensemble Monte Carlo techniques, not finding any evidence of such a transition. Additional analytical arguments are given to support this claim. Finally, we find a clustering transition when Ruelle’s stability criterion is not fulfilled. The consequences of these findings on the three-dimensional phase diagrams are also discussed.
Domain dynamics and fractal growth analysis in thin ferroelectric films
Authors: Roy Manas K. , Paul Jaita , Dattagupta Sushanta
Published: July 2010

In this article we consider the nonlinear dynamics of domain growth and dynamics under the influence of an external electric field and an intrinsic pinning field due to disorder. The theoretical framework is based on a finite time-difference method as applied to a time-dependent Ginzburg–Landau–Devonshire equation. The domain growth is seen to be of fractal nature, the fractal dimension of which is in good agreement with experiments. When it comes to dynamics we compute the areal velocity of the domain growth as a function of the applied field and find different regions of the nonlinearities that are also in qualitative agreement with experiments.
Quality analysis of selective microparticle deposition on electrically programmable surfaces
Authors: Wagner J. , Löffler F. , König K. , Fernandez S. , Nesterov-Müller A. , Breitling F. , Bischoff F. R. , Stadler V. , Hausmann M. , Lindenstruth V.
Published: July 2010

Image processing and pattern analysis can evaluate the deposition quality of triboelectrically charged microparticles on charged surfaces. The image processing method presented in this paper aims at controlling the quality of peptide arrays generated by particle based solid phase Merrifield combinatorial peptide synthesis. Incorrectly deposited particles are detected before the amino acids therein are coupled to the growing peptide. The calibration of the image acquisition is performed in a supervised training step in which all parameters of the quality analyzing algorithm are learnt given one representative image. Then, the correct deposition pattern is determined by a linear support vector machine. Knowing the pattern, contaminated areas can be detected by comparing the pattern with the actual deposition. Taking into account the resolution of the image acquisition system and its magnification factor, the number and size of contaminating particles can be calculated out of the number of connected foreground pixels.
Temperature effect on the lasing from a dye-doped two-dimensional hexagonal photonic crystal made of holographic polymer-dispersed liquid crystals
Authors: Luo D. , Sun X. W. , Dai H. T. , Demir H. V. , Yang H. Z. , Ji W.
Published: July 2010

Temperature dependent lasing was demonstrated in a dye-doped two-dimensional hexagonal photonic crystal made of holographic polymer-dispersed liquid crystals (LCs) along ΓM direction in TE polarization. A redshift in lasing peaks was observed as the temperature increased from 25 to 45 °C. The downward movement of photonic band of TE polarization, majorly caused by the decrease in the anisotropy of LC droplets with the increase in temperature, is responsible for the redshift in lasing peaks.
Enhancement of a laminar premixed methane/oxygen/nitrogen flame speed using femtosecond-laser-induced plasma
Authors: Yu Xin , Peng Jiangbo , Yang Peng , Sun Rui , Yi Yachao , Zhao Yongpeng , Chen Deying , Yu Junhua
Published: July 2010

We first investigate the effects of femtosecond-laser-induced plasma on the flame speed of a laminar premixed methane/oxygen/nitrogen flame with a wide range of the equivalence ratios (0.8–1.05) at atmospheric pressure. It is experimentally found that the flame speed increases 20.5% at equivalence ratios 1.05. The self-emission spectra from the flame and the plasma are studied and an efficient production of active radicals under the action of femtosecond (fs)-laser pulses has been observed. Based on the experimental data obtained, the presence of oxygen atom and hydrocarbon radicals is suggested to be a key factor enhancing flame speed.
Magnetization reversal and Yb3+/Cr3+ spin ordering at low temperature for perovskite YbCrO3 chromites
Authors: Su Yuling , Zhang Jincang , Feng Zhenjie , Li Li , Li Beizhan , Zhou Yun , Chen Zhenping , Cao Shixun
Published: July 2010

The temperature dependence of the dc magnetization and the specific heat capacity are systematically investigated for the perovskite YbCrO3 chromites. The results show that there exist two complex sequences of magnetic transitions with the characteristics of magnetization reversal and Yb3+/Cr3+ spin ordering at different temperature, respectively. The antiferromagneticlike transition around TN=118 K is attributed to the antiferromagnetic ordering of the Cr3+ spins and a negative magnetization, accompanied with a tendency to the plateau below 10 K caused by the Yb3+ ordering. We obtain the Weiss constant of −197.0 K and an effective moment of 5.99μB for the sum of the free ion values of 4.53μB for Yb3+ and 3.87μB for high-spin Cr3+ from the experiments, which shows an antiferromagnetic interaction and the existence of weak canted antiferromagnetic (CAFM) characteristics. Corresponding to the magnetic phase transition in the Cr sublattice, the specific heat capacity under zero fields exhibits a sharp λ-shape peak near temperature TN, which is depressed and broadened smoothly with the increase in the magnetic field. And a shoulder-shaped Schottky-type anomaly below 12 K is observed in the specific heat capacity curves. This can be interpreted by accounting for the molecular field approximation by assuming that the induced polarization of the paramagnetic ytterbium ions is opposite to the ferromagnetic moment of the chromium ions. According to the results of the zero fields cooling and the field cooling magnetization, the possible existence of spin ordering for the Yb3+ moments can be predicted.
RASOR: An advanced instrument for soft x-ray reflectivity and diffraction
Authors: Beale T. A. W. , Hase T. P. A. , Iida T. , Endo K. , Steadman P. , Marshall A. R. , Dhesi S. S. , van der Laan G. , Hatton P. D.
Published: July 2010

We report the design and construction of a novel soft x-ray diffractometer installed at Diamond Light Source. The beamline endstation RASOR is constructed for general users and designed primarily for the study of single crystal diffraction and thin film reflectivity. The instrument is comprised of a limited three circle (θ, 2θ, and χ) diffractometer with an additional removable rotation (ϕ) stage. It is equipped with a liquid helium cryostat, and post-scatter polarization analysis. Motorized motions are provided for the precise positioning of the sample onto the diffractometer center of rotation, and for positioning the center of rotation onto the x-ray beam. The functions of the instrument have been tested at Diamond Light Source, and initial test measurements are provided, demonstrating the potential of the instrument.
Hybrid conjugated polymer solar cells using patterned GaAs nanopillars
Authors: Mariani Giacomo , Laghumavarapu Ramesh B. , Tremolet de Villers Bertrand , Shapiro Joshua , Senanayake Pradeep , Lin Andrew , Schwartz Benjamin J. , Huffaker Diana L.
Published: July 2010

In this work, we study hybrid solar cells based on poly(3-hexylthiophene)-coated GaAs nanopillars grown on a patterned GaAs substrate using selective-area metal organic chemical vapor deposition. The hybrid solar cells show extremely low leakage currents (I≅45 nA @−1V) under dark conditions and an open circuit voltage, short circuit current density, and fill factor of 0.2 V, 8.7 mA/cm2, and 32%, respectively, giving a power conversion efficiency of η=0.6% under AM 1.5 G illumination. Surface passivation of the GaAs results in further improvement, yielding η=1.44% under AM 1.5 G illumination. External quantum efficiency measurements of these polymer/inorganic solar cells are also presented.
Comparison of ultraviolet- and charge-induced degradation phenomena in blue fluorescent organic light emitting diodes
Authors: Seifert Ruben , Scholz Sebastian , Lüssem Björn , Leo Karl
Published: July 2010

We compare the degradation of organic light emitting diodes (OLEDs) by UV light and by electrical driving. We prove that the exponential dependence of the half-lifetime on the current density known from electrical aging is also valid for UV-degradation. The influence of excitons on the degradation of OLEDs is determined and we experimentally distinguish between the influence of singlet and triplet excitons. We conclude that singlet excitons are the main cause of degradation for Spiro-DPVBi(2,2′,7,7′-tetrakis(2,2-diphenylvinyl)spiro-9,9′-bifluorene)-based OLEDs by a comparison of the degradation of electrically driven and UV-excited OLEDs.
On the inverse field dependence of conductivity in disordered organic materials
Authors: Ikrelef N. , Bourbie D. , Driss-Khodja K.
Published: July 2010

Recently the change in temperature dependence of conductivity observed in polymer memory device prepared from polythiophene, has been attributed to a field-induced transition from a charge-injection-limited current to a trap controlled current. Under a high electrical field, the conductivity becomes independent on temperature and depends exponentially on the inverse of the applied field. In this paper we present a theoretical interpretation of this behavior in the framework of hopping mechanism, where the physical feature is the field effect on the tunneling probability.
Importance of impurity diffusion for early stage degradation in AlGaN/GaN high electron mobility transistors upon electrical stress
Authors: Ťapajna M. , Mishra U. K. , Kuball M.
Published: July 2010

Early stage degradation of AlGaN/GaN high electron mobility transistors (HEMTs) submitted to off- and on-state voltage bias stress was studied using UV light-assisted drain current trapping characteristics. Besides electronic traps generated underneath the gate during off-state stress, both stress conditions lead to trap generation in the transistor access region close to the drain side of the gate edge. UV light-assisted trapping analysis strongly indicates these traps to be located in the AlGaN subsurface layer of the AlGaN/GaN HEMT. Trap evolution during off-state stress performed at base plate temperatures from room temperature to 150 °C was found to exhibit an activation energy of 0.26 eV, consistent with impurity diffusion along dislocations.
High-quality nanocrystalline cubic silicon carbide emitter for crystalline silicon heterojunction solar cells
Authors: Miyajima Shinsuke , Irikawa Junpei , Yamada Akira , Konagai Makoto
Published: July 2010

We developed a highly transparent n-type hydrogenated nanocrystalline cubic silicon carbide (nc-3C–SiC:H) emitter for crystalline silicon (c-Si) heterojunction solar cells. A low emitter saturation current density (J0e) of 1.4×101 fA/cm2 was obtained under optimal deposition conditions. A c-Si heterojunction solar cell fabricated on a p-type c-Si wafer without texturing showed an active area efficiency of 17.9% [open-circuit voltage (Voc)=0.668 V, short-circuit current density (Jsc)=36.7 mA/cm2, fill factor=0.731]. The high Jsc value is associated with excellent quantum efficiencies at short wavelengths (<500 nm).
Impact of applied strain on the electron transport through ferroelectric tunnel junctions
Authors: Luo Xin , Lin S. P. , Wang Biao , Zheng Yue
Published: July 2010

Combining nonequilibrium Green’s functions with density-functional theory, we have investigated the effect of external strain field on the tunneling electroresistance (TER) of ferroelectric material sandwiched between Pt electrodes. The results show that the strain induced para/ferroelectric phase transitions play an important role in the electronic transport properties of the junction. Sizable enhancements in the resistance are found for the strained ferroelectric junctions with a TER ratio of 9000%. Detail analyses show that the Ti–O displacements along the transport direction in ferroelectric barrier change the effective potential profile, resulting in a giant piezoelectric resistance in the ferroelectric tunnel junctions.
Tailoring magnetic vortices in nanostructures
Authors: Garcia F. , Westfahl H. , Schoenmaker J. , Carvalho E. J. , Santos A. D. , Pojar M. , Seabra A. C. , Belkhou R. , Bendounan A. , Novais E. R. P. , Guimarães A. P.
Published: July 2010

Tailoring the properties of magnetic vortices through the preparation of structured multilayers is discussed. The dependence of the vortex core radius r on the effective anisotropy is derived within a simple model, which agrees with our simulations. As the perpendicular anisotropy increases, r also increases until a perpendicular magnetization appears in the disk rim. Co/Pt multilayer disks were studied; x-ray microscopy confirms qualitatively the predicted behavior. This is a favorable system for implementing vortex-based spin-transfer nano-oscillator devices, with enhanced rf power resulting both from the increase in the core size and synchronization afforded by the coupling of the Co layers.
Nonlinear pH sensitivity of molecular modified transistors
Authors: Einati Hila , Novitski Roman , Shacham-Diamand Yosi
Published: July 2010

The integration of organic self-assembled monolayers (SAMs) in electronic devices is very attractive since they offer high flexibility in design and applications. This paper models the operation of functionalized field effect transistor with a liquid gate. The model explains the nonlinear response to pH variations in SAM-field effect devices. The organic monolayers have low density of sites in comparison to inorganic layers; furthermore, the transistor sensitivity to pH is low and dramatically influenced by the Helmholtz capacitance. It was proven that the dissociation constants have a strong effect on the characteristics of organic field effect device.
100 W peak-power 1 GHz repetition picoseconds optical pulse generation using blue-violet GaInN diode laser mode-locked oscillator and optical amplifier
Authors: Koda Rintaro , Oki Tomoyuki , Miyajima Takao , Watanabe Hideki , Kuramoto Masaru , Ikeda Masao , Yokoyama Hiroyuki
Published: July 2010

We have generated single-transverse-mode optical pulses with 100 W peak power and 3 ps duration at 1 GHz repetition from a blue-violet GaInN mode-locked laser diode (MLLD) and a semiconductor optical amplifier (SOA) without the use of any pulse compression. The generation of clean optical pulses without subpulse components from the MLLD and the reduction in amplified spontaneous emission in the SOA by incorporating a flare waveguide structure resulted in effective amplification of optical pulses to produce over 100 W peak power.
Characteristics of a band edge p-channel metal-oxide-semiconductor field effect transistors fabricated with a high-k /WAlx/TiSiN gate stack
Authors: Park Chang Seo , Hussain Muhamad M. , Bersuker Gennadi , Kirsch Paul D. , Jammy Raj
Published: July 2010

A metal/high-k gate stack with a p-type band edge effective work function (EWF) of about 5.0 eV is demonstrated using a thin WAlx capping layer. The WAlx stack exhibits a lower threshold voltage (higher flatband voltage) value and better equivalent oxide thickness scalability than previously reported high EWF gate stacks using an AlOx cap. The WAlx cap p-channel metal-oxide-semiconductor field-effect transistors (pMOSFETs) show significantly improved negative bias temperature instability (NBTI) characteristics than AlOx-capped pMOSFETs, which is attributed to negligible diffusion of Al into the interfacial oxide layer adjacent to the Si substrate.
Psychotic Speech: A Neurolinguistic Perspective
Authors: Anand Amit , Wales Roger J.
Published: July 2010

The existence of an aphasia-like language disorder in psychotic speech has been the subject of much debate. This paper argues that a discrete language disorder could be an important cause of the disturbance seen in psychotic speech. A review is presented of classical clinical descriptions and experimental studies that have explored the similarities between psychotic language impairment and aphasic speech. The paper proposes neurolinguistic tasks which may be used in future studies to elicit subtle language impairments in psychotic speech. The usefulness of a neurolinguistic model for further research in the aetiology and treatment of psychosis is discussed.
Career Choice and Experience of Distress Amongst Interns: A Survey of New South Wales Internship 1987–1990
Authors: Hume Frank , Wilhelm Kay
Published: July 2010

Successive cohorts of interns assigned to a Sydney teaching hospital since 1987 were interviewed at the beginning and end of their intern year to document factors influencing career choice and psychological morbidity, with comparisons between the graduates of the three NSW medical faculties. Intellectual challenge and altruism were the two most reported motivating factors in choosing Medicine. Many interns expressed regret at their career choice. Apart from anger, self-reported psychological morbidity during internship was low. Interns' evaluation of the relevance of their undergraduate training declined during internship, except for Newcastle graduates. Increased “hands on” clinical experience during undergraduate years, career guidance, assertive-ness training, and time management skills should be included in the undergraduate curriculum. More registrar teaching, frequent performance feedback, regular grievance sessions and decreased clerical activities contribute to more enriching intern experiences.
Mental Health Law: Institutionalised Discrimination
Authors: Campbell Tom D.
Published: July 2010

The aim of the paper is to propose that special mental health laws be replaced by generic protection and prevention legislation. The arguments used for the detention and compulsory treatment of persons with mental illnesses are analysed, and found not to justify protection and prevention rules which apply only to persons with mental illnesses. Two separate systems of legal intervention should be established to deal with (1) all persons in need of compulsory care and (2) all persons who require to be detained for the prevention of harm to others.
The Influence of Illness Duration on Syndrome Clarity and Stability in Functional Psychosis: Does the Diagnosis Emerge and Stabilise with Time?
Authors: McGorry Patrick D.
Published: July 2010

This review aims to examine the relationship between phase and duration of illness and the clarity and stability of syndromes in psychotic illness. Originating from clinical experience with first episode psychosis, where Neo-Kraepelinian templates and the underlying model have felt especially awkward and ill-fitting, a hypothesis that the clinical picture of functional psychosis might become clearer over time and stabilise in individual patients is proposed which involves the notion of differentiation.

A broad range of psychopathological studies and historical papers which refer directly or indirectly to the evolution of the clinical picture in psychosis over time are reviewed. The findings are difficult to interpret, since few studies have focused directly on the issue; however there is evidence of evolution over time of the clinical picture, particularly within the schizophrenia spectrum, and instability beyond this. Further research is needed to clarify the longitudinal patterns of psychopathology in psychotic illness. The capacity for evolution and instability and consequent scope for reclassification of patients has important implications for research and psychoeducation in early psychosis.
Demographic and Readmission Data in a Therapeutic Community for Black Psychiatric Patients in South Africa
Authors: Pillay Anthony L. , Vawda Naseema B.M. , Pollock Leslie R. , du Plessis Wynand F.
Published: July 2010

Therapeutic communities have an important role in adult psychiatric care. Such a hospital unit is described within a Black psychiatric hospital in South Africa. However, owing to apartheid very few Black clinical psychologists have been trained. Translators frequently have to be used in the therapeutic context, which is an unorthodox approach. Nevertheless, various therapeutic groups are conducted. Demographic and clinical data for a 3 year period are presented, showing most of the patients to be male, unmarried and around 30 years of age. Schizophrenic conditions were the most common diagnoses, with problems of self-care and low self-esteem predominating. Although a readmission rate of 22.1% was noted the lack of adequate control measures in this study must be taken into consideration.
The role of taste and oral somatosensation in olfactory localization
Authors: Stevenson Richard J. , Oaten Megan J. , Mahmut Mehmet K.
Published: July 2010

Although there is only one set of olfactory receptors, odours are experienced as smells when sniffing things (e.g., sniffing a wine's bouquet) and as flavours when the olfactory stimulus is present in the mouth (e.g., drinking wine). How this location binding—external versus internal environment—is achieved is poorly understood. Experiment 1 employed a new procedure to study localization, which was then used to explore whether localization is primarily dependent upon simultaneous oral somatosensation. Experiment 2, using solutions of varying viscosity, and Experiment 3, using oral movement of varying vigour, revealed that sniffed odours are not localized to the mouth by somatosensation alone. Instead, Experiment 4 demonstrated that a tastant needs to be present and that increasing tastant concentration generates increasing oral localization. Experiment 5 found that this reliance upon gustation reflects the previously observed “confusion” that people show for taste and smell stimuli in the mouth. We suggest that this “confusion” reflects the gustatory system's superior ability to suppress olfactory attention, thus assisting flavour binding.
David Pellman: Grasping the geometry of cancer
Authors: Sedwick Caitlin
Published: July 2010

David Pellman investigates the constraints and advantages that alteration of chromosome number places on dividing cells.
The phospholipase complex PAFAH Ib regulates the functional organization of the Golgi complex
Authors: Bechler Marie E. , Doody Anne M. , Racoosin Esther , Lin Lin , Lee Kelvin H. , Brown William J.
Published: July 2010

We report that platelet-activating factor acetylhydrolase (PAFAH) Ib, comprised of two phospholipase A2 (PLA2) subunits, α1 and α2, and a third subunit, the dynein regulator lissencephaly 1 (LIS1), mediates the structure and function of the Golgi complex. Both α1 and α2 partially localize on Golgi membranes, and purified catalytically active, but not inactive α1 and α2 induce Golgi membrane tubule formation in a reconstitution system. Overexpression of wild-type or mutant α1 or α2 revealed that both PLA2 activity and LIS1 are important for maintaining Golgi structure. Knockdown of PAFAH Ib subunits fragments the Golgi complex, inhibits tubule-mediated reassembly of intact Golgi ribbons, and slows secretion of cargo. Our results demonstrate a cooperative interplay between the PLA2 activity of α1 and α2 with LIS1 to facilitate the functional organization of the Golgi complex, thereby suggesting a model that links phospholipid remodeling and membrane tubulation to dynein-dependent transport.
Mps1 directs the assembly of Cdc20 inhibitory complexes during interphase and mitosis to control M phase timing and spindle checkpoint signaling
Authors: Maciejowski John , George Kelly A. , Terret Marie-Emilie , Zhang Chao , Shokat Kevan M. , Jallepalli Prasad V.
Published: July 2010

The spindle assembly checkpoint (SAC) in mammals uses cytosolic and kinetochore-based signaling pathways to inhibit anaphase. In this study, we use chemical genetics to show that the protein kinase Mps1 regulates both aspects of the SAC. Human MPS1-null cells were generated via gene targeting and reconstituted with either the wild-type kinase (Mps1wt) or a mutant version (Mps1as) sensitized to bulky purine analogues. Mps1 inhibition sharply accelerated anaphase onset, such that cells completed mitosis in 12 min, and prevented Cdc20’s association with either Mad2 or BubR1 during interphase, i.e., before the appearance of functional kinetochores. Furthermore, intramitotic Mps1 inhibition evicted Bub1 and all other known SAC transducers from the outer kinetochore, but contrary to a recent study, did not perturb aurora B–dependent phosphorylation. We conclude that Mps1 has two complementary roles in SAC regulation: (1) initial cytoplasmic activation of Cdc20 inhibitors and (2) recruitment of factors that promote sustained anaphase inhibition and chromosome biorientation to unattached kinetochores.
The cell biology of hearing
Authors: Schwander Martin , Kachar Bechara , Müller Ulrich
Published: July 2010

Mammals have an astonishing ability to sense and discriminate sounds of different frequencies and intensities. Fundamental for this process are mechanosensory hair cells in the inner ear that convert sound-induced vibrations into electrical signals. The study of genes that are linked to deafness has provided insights into the cell biological mechanisms that control hair cell development and their function as mechanosensors.
Limit distributions of the minimax of independent identically distributed random variables
Authors: Chernoff Herman , Teicher Henry
Published: July 2010

The class of limiting distributions of the normalized minimax (or maximin) of independent identically distributed random variables is obtained and the domains of attraction of the three limiting types are characterized. Asymptotic independence of the minimax and maximin is also demonstrated.
On the domain of normality of an attractive fixpoint
Authors: Bhattacharyya P.
Published: July 2010

It is proved that an entire function of order less than12\frac {1}{2}has no unbounded immediate domains of attraction for any of its fixpoints. Estimates for the growth of functions with large infinite domains of attraction (e.g. including half planes) are obtained. It is shown that an entire function mapping an infinite domain into itself has polynomial growth in such domains.
Principal homogeneous spaces and group scheme extensions
Authors: Waterhouse William C.
Published: July 2010

Suppose

G
G

is a finite commutative group scheme over a ring

R
R

. Using Hopf-algebraic techniques, S. U. Chase has shown that the group of principal homogeneous spaces for

G
G

is isomorphic to

Ext
⁡
(

G
′

,

G
m

)

\operatorname {Ext} (G’,{G_m})

, where

G
′

G’

is the Cartier dual to

G
G

and the Ext is in a specially-chosen Grothendieck topology. The present paper proves that the sheaf

Ext
⁡
(

G
′

,

G
m

)

\operatorname {Ext} (G’,{G_m})

vanishes, and from this derives a more general form of Chase’s theorem. Our Ext will be in the usual (fpqc) topology, and we show why this gives the same group. We also give an explicit isomorphism and indicate how it is related to the existence of a normal basis.
A generalized dual for a 𝐶*-algebra
Authors: Halpern Herbert
Published: July 2010

Let

A

\mathcal {A}

be a

C
∗

{C^ \ast }

-algebra, let

B

\mathcal {B}

be its enveloping von Neumann algebra, and let

F

\mathcal {F}

be the center of

B

\mathcal {B}

. Let

B

∼

{\mathcal {B}_ \sim }

be the set of all

σ
\sigma

-weakly continuous

F

\mathcal {F}

-module homomorphisms of the

F

\mathcal {F}

-module

B

\mathcal {B}

into

F

\mathcal {F}

and let

A

∼

{\mathcal {A}^ \sim }

be the set of all restrictions to

A

\mathcal {A}

of elements of

B

∼

{\mathcal {B}_ \sim }

. Then

A

\mathcal {A}

is classified as CCR, GCR, and NGCR in terms of certain naturally occurring topologies on

A

∼

{\mathcal {A}^ \sim }

.
Ordered inverse semigroups
Authors: Saitô Tôru
Published: July 2010

In this paper, we consider two questions: one is to characterize the structure of ordered inverse semigroups and the other is to give a condition in order that an inverse semigroup is orderable. The solution of the first question is carried out in terms of three types of mappings. Two of these consist of mappings of an

R

\mathcal {R}

-class onto an

R

\mathcal {R}

-class, while one of these consists of mappings of a principal ideal of the semilattice

E
E

constituted by idempotents onto a principal ideal of

E
E

. As for the second question, we give a theorem which extends a well-known result about groups that a group

G
G

with the identity

e
e

is orderable if and only if there exists a subsemigroup

P
P

of

G
G

such that

P
∪

P

−
1

=
G
,
P
∩

P

−
1

=
{
e
}

P \cup {P^{ - 1}} = G,P \cap {P^{ - 1}} = \{ e\}

and

x
P

x

−
1

⫅
P

xP{x^{ - 1}} \subseteqq P

for every

x
∈
G

x \in G

.
On higher-dimensional fibered knots
Authors: Andrews J. J. , Sumners D. W.
Published: July 2010

The geometrical properties of a fibration of a knot complement over

S
1

{S^1}

are used to develop presentations for the homotopy groups as modules over the fundamental group. Some homotopy groups of spun and twist-spun knots are calculated.
The structure of pseudocomplemented distributive lattices. I. Subdirect decomposition
Authors: Lakser H.
Published: July 2010

In this paper all subdirectly irreducible pseudocomplemented distributive lattices are found. This result is used to establish a Stone-like representation theorem conjectured by G. Grätzer and to find all equational subclasses of the class of pseudocomplemented distributive lattices.
Convex hulls of some classical families of univalent functions
Authors: Brickman L. , MacGregor T. H. , Wilken D. R.
Published: July 2010

Let S denote the functions that are analytic and univalent in the open unit disk and satisfy

f
(
0
)
=
0

f(0) = 0

and

f
′

(
0
)
=
1

f’(0) = 1

. Also, let K, St,

S
R

{S_R}

, and C be the subfamilies of S consisting of convex, starlike, real, and close-to-convex mappings, respectively. The closed convex hull of each of these four families is determined as well as the extreme points for each. Moreover, integral formulas are obtained for each hull in terms of the probability measures over suitable sets. The extreme points for each family are particularly simple; for example, the Koebe functions

f
(
z
)
=
z

/

(
1
−
x
z

)
2

,

|

x

|

=
1

f(z) = z/{(1 - xz)^2},|x| = 1

, are the extreme points of cl co St. These results are applied to discuss linear extremal problems over each of the four families. A typical result is the following: Let J be a “nontrivial” continuous linear functional on the functions analytic in the unit disk. The only functions in St. that satisfy

Re

J
(
f
)
=
max

{
Re

J
(
g
)
:
g
∈
S
t
}

\operatorname {Re} \,J(f) = \max \;\{ \operatorname {Re} \;J(g):g \in St\}

are Koebe functions and there are only a finite number of them.