bluuebunny/crossref_metadata_2025 huggingface dataset:
Genocide and the Psychology of Perpetrators, Bystanders, and Victims
Authors: Thalhammer Kristina E.
Published: May 2012

We live in a world laced with forms of political violence. Kristen Renwick Monroe's latest work develops an interesting social psychological account of the conduct of victims, perpetrators, and bystanders of the most extreme form of violence—genocide. It also employs an interesting narrative approach that contributes to broad methodological discussions in political science about the ways in which subjective experience can best be understood. We have thus invited a diverse group of political scientists and historians to comment on the book's analysis of political violence and on its broader approach to the study of politics.—Jeffrey C. Isaac, Editor
Genocide and the Psychology of Perpetrators, Bystanders, and Victims
Authors: Tronto Joan C.
Published: May 2012

We live in a world laced with forms of political violence. Kristen Renwick Monroe's latest work develops an interesting social psychological account of the conduct of victims, perpetrators, and bystanders of the most extreme form of violence—genocide. It also employs an interesting narrative approach that contributes to broad methodological discussions in political science about the ways in which subjective experience can best be understood. We have thus invited a diverse group of political scientists and historians to comment on the book's analysis of political violence and on its broader approach to the study of politics.—Jeffrey C. Isaac, Editor
Daytime additional F layer stratification over low‐midlatitude station of the Indian sector under geomagnetic disturbed conditions
Authors: Yadav Sneha , Upadhayaya A. K. , Das Rupesh M.
Published: May 2012

In this paper, the observations of additional F layer stratification are presented in a region which is situated at the outer edge of equatorial ionization anomaly (EIA) zone. The digital ionosonde data observed over Delhi (28.6° N, 77.2° E, dip 42.44° N) during March–April, 2001 has been used to carry out the present work. The observational period was geomagnetically disturbed and represents the high solar activity phase of 23rd solar cycle. The additional transient cusp is frequently observed in the considered months before the noon hours; however, in this paper only five prominent cases are presented. From the analysis of ionograms, it is observed that the transient additional cusp is formed between the pre‐existing F1 and F2 layer; hence, named as the cusp of F1.5. Study reveals that the Traveling Atmospheric Disturbances (TADs) along with the vertical expansion of F layer provides the necessary condition for the existence of this transient feature. The intensification of F1 layer along with increased altitude immediately after the disappearance of additional stratification remains one of the fascinating features of the present results. The present investigation demonstrates that the daytime F1 and F2 region over low‐midlatitude station is strongly modulated by the passage of TIDs, originating at high latitudes or by atmospheric disturbances of local origin during the high solar activity period. The concurrent presence of TADs and the associated disturbance composition appears to be plausible reason behind the present observations.
Investigation of land ice‐ocean interaction with a fully coupled ice‐ocean model: 2. Sensitivity to external forcings
Authors: Goldberg D. N. , Little C. M. , Sergienko O. V. , Gnanadesikan A. , Hallberg R. , Oppenheimer M.
Published: May 2012

A coupled ice stream‐ice shelf‐ocean cavity model is used to assess the sensitivity of the coupled system to far‐field ocean temperatures, varying from 0.0 to 1.8°C, as well as sensitivity to the parameters controlling grounded ice flow. A response to warming is seen in grounding line retreat and grounded ice loss that cannot be inferred from the response of integrated melt rates alone. This is due to concentrated thinning at the ice shelf lateral margin, and to processes that contribute to this thinning. Parameters controlling the flow of grounded ice have a strong influence on the response to sub‐ice shelf melting, but this influence is not seen until several years after an initial perturbation in temperatures. The simulated melt rates are on the order of that observed for Pine Island Glacier in the 1990s. However, retreat rates are much slower, possibly due to unrepresented bedrock features.
High precision U/Pb zircon dating of the Chaltén Plutonic Complex (Cerro Fitz Roy, Patagonia) and its relationship to arc migration in the southernmost Andes
Authors: Ramírez de Arellano Cristobal , Putlitz Benita , Müntener Othmar , Ovtcharova Maria
Published: May 2012

We report new high‐precision U/Pb ages and geochemical data from the Chaltén Plutonic Complex to better understand the link between magmatism and tectonics in Southern Patagonia. This small intrusion located in the back‐arc region east of the Patagonian Batholith provides important insights on the role of arc migration and subduction erosion. The Chaltén Plutonic Complex consists of a suite of calc‐alkaline gabbroic to granitic rocks, which were emplaced over 530 kyr between 16.90 ± 0.05 Ma and 16.37 ± 0.02 Ma. A synthesis of age and geochemical data from other intrusions in Patagonia reveals (a) striking similarities between the Chaltén Plutonic Complex and the Neogene intrusions of the batholith and differences to other back‐arc intrusions such as Torres del Paine (b) a distinct E‐W trend of calc‐alkaline magmatic activity between 20 and 17 Ma. We propose that this trend reflects the eastward migration of the magmatic arc, and the consistent age pattern between the subduction segments north and south of the Chile triple junction suggests a causal relation with a period of fast subduction of the Farallón‐Nazca plate during the Early Miocene. Previously proposed flat slab models are not consistent with the present location and morphology of the Southern Patagonian Batholith. We advocate, alternatively, that migration of the magmatic arc is caused by subduction erosion due to the increasing subduction velocities during the Early Miocene.
Clinical Relevance of Biomarkers for Traumatic Brain Injury
Authors: Bettermann Kerstin , Slocomb Julia E.
Published: May 2012

Approximately 1.4 million people in the United States sustain a traumatic brain injury (TBI) each year, resulting in more than 235 000 hospitalizations and 50 000 deaths. An estimated 5.3 million Americans have current long-term disabilities as a result of TBI, which results in an estimated $60 billion in healthcare expenditures. Mild TBI (mTBI), which accounts for 80% to 90% of all cases, is the most prevalent form of brain injury in athletes. Many of these traumas still remain undetected, as they are difficult to diagnose. New biomarkers of TBI may allow more rapid diagnosis of TBI, improving early identification and treatment, and could help to predict clinical outcome. The field of TBI biomarkers is rapidly evolving. This chapter will discuss some of the most clinically relevant biomarkers for TBI that have been recently studied in human subjects.
Mitochondrial Dysfunctions and Markers of Spinal Cord Injury
Authors: Panov Alexander V.
Published: May 2012

In patients with spinal cord injury (SCI), the primary or mechanical trauma seldom causes total transection, even though functional loss may be complete. The primary injury is immediately followed by various systemic and local pathological events, known as secondary injury mechanisms, which within a few hours may turn an incomplete injury into complete injury of the traumatized spinal cord. Analysis of the literature has revealed to date only two reliable biomarkers, namely S100β and neuron-specific enolase (NSE), that change with time and reflect SCI severity. S100β marks the process of demyelination and NSE the death of neurons in the traumatized region. Mitochondria play the decisive role in excitotoxic cell death, which occurs within 4 to 12 hours after SCI. The time line of neurodegeneration and appearance of markers depend on severity of the secondary injury mechanisms. S100β and NSE, as markers of acute stage SCI, have little use for clinicians, but have utility in understanding experimental SCI. Mitochondria are vital for survival of neurons; therefore, it is necessary to search for markers that would characterize the state of these organelles as well as being useful for clinicians.
Protein S100B in Traumatic Brain Injury
Authors: Åstrand Ramona , Undén Johan , Romner Bertil
Published: May 2012

Protein S100B is a small calcium-binding protein expressed in astroglial cells in the central nervous system. Its concentration increases in cerebrospinal fluid and blood after traumatic brain injury. There are several commercially available methods for analyzing serum S100B. The clinical use of serum S100B is mainly in minor head injury, as a complement to existing guidelines in order to help clinicians to determine who could safely be discharged without a previous CT scan. S100B in severe TBI is still being studied as a marker for secondary neurological complications, but has not yet had an impact in this specific area. Recent research on the clinical use of S100B in pediatric TBI has shown promising results, and the introduction of S100B in minor head injuries could have even greater impact than for adults. However, more research needs to be done before a biomarker can be clinically used in pediatric TBI.
Towards Biomolecular Simulations with Explicit Inclusion of Polarizability: Development of a CHARMM Polarizable Force Field based on the Classical Drude Oscillator Model
Authors: Baker C. M. , Darian E. , MacKerell Jr A. D.
Published: May 2012

Molecular dynamics simulations, based on molecular mechanics force fields, have been instrumental in increasing our understanding of a range of biomolecular systems. Most of the force fields commonly used for the simulation of biomolecules, however, represent electrostatic properties by a set of fixed partial atomic charges and are referred to as additive force fields. This approach is problematic because it does not explicitly include polarizability, an important component of the electrostatic interaction arising from the response of the molecular dipoles to an external electric field.

To overcome this problem, multiple efforts are currently underway to develop force fields including an explicit representation of polarizability: one such effort is the CHARMM Drude polarizable force field. In this chapter, we begin by discussing the development and implementation of the theory associated with the Drude model, as well as a robust scheme for parameter optimization. This is followed by discussion of the way in which these tools are being used to optimize a polarizable force field for the simulation of biomolecules. The primary focus has been the development of parameters for small molecule analogues of functional groups present within biomolecules, but is shifting to the optimization of covalent connections between these small molecules, and testing of the resulting parameters in fully hydrated biomolecules. For the nucleic acids a case study is presented, illustrating that the polarizable force field already reveals atomic-level details not observed with an additive force field.
Integral Equation Theory of Biomolecules and Electrolytes
Authors: Luchko Tyler , Joung In Suk , Case David A.
Published: May 2012

The so-called three-dimensional version (3D-RISM) can be used to describe the interactions of solvent components (here we treat water and ions) with a chemical or biomolecular solute of arbitrary size and shape. Here we give an overview of the current status of such models, describing some aspects of “pure” electrolytes (water plus simple ions) and of ionophores, proteins and nucleic acids in the presence of water and salts. Here we focus primarily on interactions with water and dissolved salts; as a practical matter, the discussion is mostly limited to monovalent ions, since studies of divalent ions present many difficult problems that have not yet been addressed. This is not a comprehensive review, but covers a few recent examples that illustrate current issues.
Computing Reaction Rates in Bio-molecular Systems Using Discrete Macro-states
Authors: Darve Eric , Ryu Ernest
Published: May 2012

We discuss different techniques to calculate reaction rates in biomolecular systems. We first review historically the first approaches based on reactive flux, which make certain simplifying assumptions in order to derive relatively simple formulas to estimate rates. Then we discuss a series of methods that attempt to do a more direct calculation based on path sampling, and related techniques such as transition interface sampling, forward flux sampling, and milestoning. Another set of approaches is based on the concept of metastability and includes techniques like conformational dynamics and recently developed methods such as Markov state models that are based on these concepts. Some recent methods attempt to combine the macro-state division of space used in Markov state models with transition path sampling in order to deal with systems exhibiting long memory, for which Markovian models are not sufficiently accurate. Such methods include weighted ensemble Brownian dynamics and non-equilibrium umbrella sampling. Finally, we include a numerical analysis of Markov state models to understand systematic and statistical errors and their behavior, along with some numerical benchmarks to illustrate the results.
Challenges in Applying Monte Carlo Sampling to Biomolecular Systems
Authors: Mezei M.
Published: May 2012

The aim of this chapter is, instead of reviewing the considerable progress made so far, to discuss the obstacles that prevent the wider use of the Monte Carlo method for macromolecular simulations. Successful adoption of the Monte Carlo method for conformational sampling of macromolecular assemblies requires solution(s) to the following problems: (1) convince investigators that it is worth it; (2) devise move sets that generate large enough correlated changes that can be accepted with reasonable probability; (3) develop efficient treatment of non-pairwise additive potentials; (4) develop efficient treatment of long-range contributions to the system's energy; and (5) the efficient parallelization of the algorithm. In the remainder of this chapter these issues will be treated one by one.
Generalised Multi-level Coarse-grained Molecular Simulation and its Application to Myosin-V Movement
Authors: Taylor William R. , Katsimitsoulia Zoe
Published: May 2012

In this chapter, we will give an overview of a new generalised coarse-grained simulation method that we have developed with a view to simulating the motion of large macromolecular systems and, in particular, molecular motors.
Modelling Nucleic Acid Structure and Flexibility: From Atomic to Mesoscopic Scale
Authors: Lankaš Filip
Published: May 2012

This chapter surveys some of the recent developments in coarse-grained modelling of nucleic acids. We first discuss models based on pseudoatoms, effective spherical particles representing groups of atoms. A major part of the chapter is devoted to models in which bases or base pairs are represented as independent, interacting rigid bodies. Two popular definitions of internal coordinates, as implemented in the programs 3DNA and Curves+, are outlined from a common perspective. Recently developed rigid base and basepair models with nonlocal quadratic interactions are presented. A statistical mechanical description of the models on their full phase space yields exact relations between model parameters and expected values of some state functions. We estimated shape and stiffness parameters for nonlocal rigid base and basepair models of a DNA oligomer containing A-tract. The parameterization is based on atomic-resolution molecular dynamics simulation data. We found that the rigid base model is consistent with a local interaction pattern, while interactions in the rigid basepair model are visibly non-local, in agreement with earlier findings. Differences in shape and stiffness parameters obtained using Curves+ and 3DNA coordinates are found to be small for structures within the B-DNA family. Anharmonic effects, coarser models, and other approaches to describe nucleic acid structure and flexibility are discussed.
Intrinsic Motions of DNA Polymerases Underlie Their Remarkable Specificity and Selectivity and Suggest a Hybrid Substrate Binding Mechanism
Authors: Foley Meredith C. , Arora Karunesh , Schlick Tamar
Published: May 2012

DNA polymerases have essential roles in DNA replication and repair. Deciphering the subtle details of the dynamical motion of different polymerases may help in identifying common features of polymerase mechanisms. Here, we analyze by principal component and covariance analyses the essential motions of several X-family DNA polymerases (β, λ, X, and µ) bound to correct and incorrect nucleotides as well as mutant and misaligned DNA complexes bound to the correct nucleotide. Results reveal distinct trends in subdomain/active-site residue motions before correct and incorrect nucleotide insertion that correlate with misinsertion efficiency. For example, correct/incorrect nucleotides enhance/reduce certain correlated motions that impact proper assembly of the active site for catalysis. In like manner, pol λ aligned and misaligned DNA complexes show nearly identical correlated motions, which agrees with pol λ's efficient correct nucleotide insertion within both substrates. Moreover, mutations in pol β's regions of correlated motions have been shown to affect substrate binding, function, and fidelity. Such correlated motion of DNA polymerases can be useful in identifying potential mutations that impair polymerase function and fidelity. It also suggests a ligand-binding mechanism that merges induced-fit with conformational sampling and could assist in the development of therapeutic agents for DNA repair-related diseases.
Monte Carlo Simulations of Nucleosome Chains to Identify Factors that Control DNA Compaction and Access
Authors: Rippe Karsten , Stehr Rene , Wedemann Gero
Published: May 2012

Despite extensive research over the last three decades, the spatial organization of the nucleosome chain in chromatin is still only partially understood, although the nucleosome structure as its basic building block is known at atomic resolution. Here, we discuss the application of Monte Carlo simulations to investigate the conformational flexibility of the nucleosome chain in a systematic manner. Its folding into compacted structures provides an additional layer for regulating access to the DNA sequence information. The contributions of nucleosome positioning, local nucleosome geometry, nucleosome-nucleosome and histone octamer-DNA interactions into MC models are considered. It is discussed how relatively minor local variations of the nucleosome structure can translate into large changes of the overall conformation of the nucleosome chain.
Humanitarian Audiology: Overview and Report of an Indian Experience
Authors: Miller Sharon , Rao Aparna
Published: May 2012

Today, audiologists are traveling to various parts of the world to provide humanitarian services. While these experiences provide ample opportunity for professional and personal growth, it is important to remember that these missions involve certain professional obligations. Professionals interested in such missions should equip themselves with as much information as possible before embarking on the trip and try to arrange for follow-up services for those served. The authors discuss some ways to achieve these two crucial goals. This is followed by the first author's experiences on a humanitarian trip to India completed in January 2010.
Analytic gradient for second order Møller-Plesset perturbation theory with the polarizable continuum model based on the fragment molecular orbital method
Authors: Nagata Takeshi , Fedorov Dmitri G. , Li Hui , Kitaura Kazuo
Published: May 2012

A new energy expression is proposed for the fragment molecular orbital method interfaced with the polarizable continuum model (FMO/PCM). The solvation free energy is shown to be more accurate on a set of representative polypeptides with neutral and charged residues, in comparison to the original formulation at the same level of the many-body expansion of the electrostatic potential determining the apparent surface charges. The analytic first derivative of the energy with respect to nuclear coordinates is formulated at the second-order Møller-Plesset (MP2) perturbation theory level combined with PCM, for which we derived coupled perturbed Hartree-Fock equations. The accuracy of the analytic gradient is demonstrated on test calculations in comparison to numeric gradient. Geometry optimization of the small Trp-cage protein (PDB: 1L2Y) is performed with FMO/PCM/6-31(+)G(d) at the MP2 and restricted Hartree-Fock with empirical dispersion (RHF/D). The root mean square deviations between the FMO optimized and NMR experimental structure are found to be 0.414 and 0.426 Å for RHF/D and MP2, respectively. The details of the hydrogen bond network in the Trp-cage protein are revealed.
Determination of maximum power transfer conditions of bimorph piezoelectric energy harvesters
Authors: Ahmad Mahmoud Al , Elshurafa A. M. , Salama K. N. , Alshareef H. N.
Published: May 2012

In this paper, a method to find the maximum power transfer conditions in bimorph piezoelectric-based harvesters is proposed. Explicitly, we derive a closed form expression that relates the load resistance to the mechanical parameters describing the bimorph based on the electromechanical, single degree of freedom, analogy. Further, by taking into account the intrinsic capacitance of the piezoelectric harvester, a more descriptive expression of the resonant frequency in piezoelectric bimorphs was derived. In interest of impartiality, we apply the proposed philosophy on previously published experimental results and compare it with other reported hypotheses. It was found that the proposed method was able to predict the actual optimum load resistance more accurately than other methods reported in the literature.
High thermal conductivity epoxy-silver composites based on self-constructed nanostructured metallic networks
Authors: Pashayi Kamyar , Fard Hafez Raeisi , Lai Fengyuan , Iruvanti Sushumna , Plawsky Joel , Borca-Tasciuc Theodorian
Published: May 2012

We demonstrate epoxy-silver nanoparticle composites with high thermal conductivity κ enabled by self-constructed nanostructured networks (SCNN) forming during the curing process at relatively low temperatures (150 °C). The networks formation mechanism involves agglomeration of the polyvinylpyrrolidone (PVP) coated nanoparticles, PVP removal, and sintering of the nanoparticles at suppressed temperatures induced by their small diameters (20–80 nm). Sintering and the SCNN formation are supported by differential scanning calorimetry and electron microscopy investigations. The formation of SCNN with high aspect ratio structures leads to enhancements in the measured thermal conductivity κ of the composite by more than two orders of magnitude versus the pure epoxy. However, κ enhancements are modest if microparticles (1.8–4.2 μm) are employed instead of PVP coated nanoparticles. The κ trends are qualitatively explained using a percolating threshold thermal conductivity model for the microcomposites. For the nanocomposites the measured κ is ∼14% of the upper limit value predicted by the Hashin and Shtrikman (H-S) theory for an ideally connected network, a measure of the non-ideal network inside the nanocomposites.
The electronic structure of free aluminum clusters: Metallicity and plasmons
Authors: Andersson Tomas , Zhang Chaofan , Tchaplyguine Maxim , Svensson Svante , Mårtensson Nils , Björneholm Olle
Published: May 2012

The electronic structure of free aluminum clusters with ∼3–4 nm radius has been investigated using synchrotron radiation-based photoelectron and Auger electron spectroscopy. A beam of free clusters has been produced using a gas-aggregation source. The 2p core level and the valence band have been probed. Photoelectron energy-loss features corresponding to both bulk and surface plasmon excitation following photoionization of the 2p level have been observed, and the excitation energies have been derived. In contrast to some expectations, the loss features have been detected at energies very close to those of the macroscopic solid. The results are discussed from the point of view of metallic properties in nanoparticles with a finite number of constituent atoms.
Scrape-off layer tokamak plasma turbulence
Authors: Bisai N. , Singh R. , Kaw P. K.
Published: May 2012

Two-dimensional (2D) interchange turbulence in the scrape-off layer of tokamak plasmas and their subsequent contribution to anomalous plasma transport has been studied in recent years using electron continuity, current balance, and electron energy equations. In this paper, numerically it is demonstrated that the inclusion of ion energy equation in the simulation changes the nature of plasma turbulence. Finite ion temperature reduces floating potential by about 15% compared with the cold ion temperature approximation and also reduces the radial electric field. Rotation of plasma blobs at an angular velocity about 1.5×105 rad/s has been observed. It is found that blob rotation keeps plasma blob charge separation at an angular position with respect to the vertical direction that gives a generation of radial electric field. Plasma blobs with high electron temperature gradients can align the charge separation almost in the radial direction. Influence of high ion temperature and its gradient has been presented.
Comment on “Electron acceleration by a short laser beam in the presence of a long-wavelength electromagnetic wave” [J. Appl. Phys. 102, 056106 (2007)]
Authors: Yuan C. J. , Huang S. J. , Wang J. X. , Wang P. X.
Published: May 2012

Gupta et al. [J. Appl. Phys. 102, 056106 (2007)] investigated vacuum electron acceleration by a short laser beam in the presence of a long-wavelength electromagnetic wave. However, we consider that their simulation results to be questionable. We have investigated their simulation in detail and present our own simulation results, which do not match the good acceleration as theirs given in the original paper.
Analytic model of energy spectrum and absorption spectra of bilayer graphene
Authors: Chang C. P.
Published: May 2012

A model to obtain the analytical form of energy spectrum and eigenvectors of the Beranl bilayer graphene, with all the tight-binding parameters included, is proposed. The bonding and anti-bonding states, linked together by a coupling term, are not completely decoupled through the chosen symmetrized wave functions. We show that such a coupling term, originating from the tight-binding parameter γ3, can be neglected and that the decoupled bonding and anti-bonding states are, respectively, described by a 2×2 matrix. The analytical energy spectrum and eigenvectors are obtained and applied to express the optical dipole matrix in a closed form, which determines the feature of optical absorption spectra. Four possible interband transitions, causing four sub-spectra, at zero temperature are allowed at chemical potential μ=0. The fine structures of total absorption spectra result form the superposition of four sub-spectra. Most importantly, comparison with the AA-stacking bilayer graphene exhibits that the energy spectra, eigenstates, and optical properties are strongly dependent on the stacking ordering.
Study of generalized magneto-optical ellipsometry measurement reliability
Authors: Arregi J. A. , Gonzalez-Diaz J. B. , Bergaretxe E. , Idigoras O. , Unsal T. , Berger A.
Published: May 2012

We present an experimental and theoretical study of the reliability of generalized magneto-optical ellipsometry measurements, investigate its dependence from data set acquisition geometries, as well as investigate the underlying physics of light reflection for magneto-optical materials to explain the observed behavior. Specifically, we compare the use of two different grids of data points and evaluate their reliability and repeatability in a comparative study. We find that the conventionally used square grid is actually not ideal for generalized magneto-optical ellipsometry (GME) measurements and that the also investigated diagonal lattice is clearly superior. These experimental results were reproduced in theoretical calculations of the detection process. The physical origin of this behavior was identified to be related to the “quality” of the individual data points that are included in the data analysis process, with the highest quality data being achieved near the crossed polarizer line, i.e., the region that is more prominently utilized in the diagonal grid approach presented here. These results will help to improve the precision and the data acquisition time of GME measurements.
Bright upconversion luminescence and increased Tc in CaBi2Ta2O9:Er high temperature piezoelectric ceramics
Authors: Peng Dengfeng , Wang Xusheng , Xu Chaonan , Yao Xi , Lin Jian , Sun Tiantuo
Published: May 2012

Er3+ doped CaBi2Ta2O9 (CBT) bismuth layered-structure high temperature piezoelectric ceramics were synthesized by the traditional solid state method. The upconversion (UC) emission properties of Er3+ doped CBT ceramics were investigated as a function of Er3+ concentration and incident pump power. A bright green upconverted emission was obtained under excitation 980 nm at room temperature. The observed strong green and weak red emission bands corresponded to the transitions from 4S3/2 and 4F9/2 to 4I15/2, respectively. The dependence of UC emission intensity on pumping power indicated that a three-photon process was involved in UC emissions. Studies of dielectric with temperature have also been carried out. Introduction of Er increased the Curie temperature of CBT, thus, making this ceramic suitable for sensor applications at higher temperatures. Because of its strong up-converted emission and increased Tc, the multifunctional high temperature piezoelectric ceramic may be useful in high temperature sensor, fluorescence thermometry, and optical-electro integration applications.
Enhanced room-temperature ferromagnetism in un-doped ZnO thin films by thermal annealing in a strong magnetic field
Authors: Zhan Peng , Wang Weipeng , Xie Qian , Li Zhengcao , Zhang Zhengjun
Published: May 2012

Room-temperature ferromagnetism was achieved in un-doped ZnO films by annealing the films in flowing argon at 650 °C. The ferromagnetic property of the ZnO films can be manipulated by applying an external magnetic field during annealing, with a maximum of 2.7 emu/g achieved at a field of 7 T, which is almost double that when no magnetic field was applied. The reason is that the magnetic field influenced greatly the involvement of oxygen defects which are origin of the ferromagnetism of these un-doped ZnO films.
High mobility In0.53Ga0.47As quantum-well metal oxide semiconductor field effect transistor structures
Authors: Yang Li , Cheng Cheng-Wei , Bulsara Mayank T. , Fitzgerald Eugene A.
Published: May 2012

In this paper, we demonstrate high electron mobility In0.53Ga0.47As quantum-well metal oxide semiconductor field effect transistor (MOSFET) structures. The Al2O3 (gate dielectric)/ In0.53Ga0.47As-In0.52Al0.48As (barrier)/In0.53Ga0.47As (channel) structures were fabricated, and the mobility was obtained by Hall measurements. The structures with in-situ chemical vapor deposition (CVD) Al2O3 displayed higher mobility than identical structures fabricated with in situ atomic layer deposition Al2O3, which indicates that CVD process resulted in a lower Al2O3/In0.53Ga0.47As interfacial defect density. A gate bias was applied to the structure with CVD Al2O3, and a peak mobility of 9243 cm2/V s at a carrier density of 2.7 × 1012 cm−2 was demonstrated for the structure with a 4 nm In0.53Ga0.47As-In0.52Al0.48As barrier. A model based on internal phonon scattering and interfacial defect coulomb scattering was developed to explain the experimental data and predict the mobility of In0.53Ga0.47As MOSFET structures.
Phase evolution and room-temperature photoluminescence in amorphous SiC alloy
Authors: Zhou H. P. , Xu M. , Wei D. Y. , Ong T. , Xiao S. Q. , Xu L. X. , Huang S. Y. , Guo Y. N. , Khan S. , Xu S.
Published: May 2012

Amorphous SiC thin films with varying phases and compositions have been synthesized using a low frequency inductively coupled high density plasma source in a hydrogen diluted methane (CH4) and silane (SiH4) mixture. The optical and electrical properties along with the microstructures of the thin films are systematically investigated. The feedstock gas ratio of CH4/SiH4 leads to the fluctuations of the optical bandgap, the carbon content, and the transition of Si–Si bonding structure from crystalline to intermediate phase and finally to amorphous phase. Room temperature photoluminescence (PL) with nearly fixed emission energy has been observed in the thin films. The underlying PL mechanism is explained in the framework of quantum confinement-luminescence center model. The photoexcitation process occurs in the nc-Si quantum dots embedded in the host SiC matrix, whereas the photoemission process occurs in the luminescence centers in the surrounding SiC or at SiC-Si interfaces. The PL evolution with the chemical composition in the films is analyzed in terms of the density of the Si quantum dots and the Si–C bond.
The recovery mechanism of the light-induced instability of the amorphous InGaZnO thin film transistors
Authors: Wang Chao-Lung , Cheng Huang-Chung , Wu Chun-Yu , Lee I-Che , Cheng Yu-Ting , Yang Po-Yu , Tsai Chih-Hung , Fang Chun-Hsiang , Lee Chung-Chun
Published: May 2012

The recovery mechanism of the light-induced instability of amorphous InGaZnO thin-film transistors was examined. Following light illumination, the bare devices displayed more dark recovery of the threshold voltage (Vth) shifts than the ones encapsulated in nitrogen ambient. This was attributed to the adsorption of more oxygen (O2) in the back channel of the bare devices. Further, much more recovery was also observed for the bare devices than the nitrogen-encapsulated ones under positive gate bias. This implied the recovery effect under gate bias could be further enhanced because the induced electrons could greatly increase the adsorption of more O2 for the bare devices.
High-speed metal-insulator transition in vanadium dioxide films induced by an electrical pulsed voltage over nano-gap electrodes
Authors: Leroy J. , Crunteanu A. , Bessaudou A. , Cosset F. , Champeaux C. , Orlianges J.-C.
Published: May 2012

We report the fabrication of VO2-based two terminal devices with ∼125-nm gaps between the two electrodes, using a simple, cost-effective method employing optical lithography and shadow evaporation. Current-voltage characteristics of the obtained devices show a main abrupt metal-insulator transition (MIT) in the VO2 film with voltage threshold values of several volts, followed by secondary MIT steps due to the nanostructured morphology of the layer. By applying to the two-terminal device a pulsed voltage over the MIT threshold, the measured switching time was as low as 4.5 ns and its value does not significantly change with device temperature, supporting the evidence of an electronically driven MIT.
Controlling photo-induced spectral changes in CdSe/ZnS quantum dots by tuning inter-dot energy transfer
Authors: Shcherbatyuk G. V. , Talbot P. , Ghosh S.
Published: May 2012

We study photo-induced spectral changes in films containing two sizes of chemically synthesized CdSe/ZnS quantum dots (QDs) using static and time-resolved spectroscopies. As the concentration of the smaller (donor) QDs is varied over two orders of magnitude relative to the larger (acceptor) dots, we find that with decreasing proportion of donors, the photo-oxidation rate increases in acceptors but slows down in donors. We conclude that these differences originate from the variations in the amount of inter-dot energy transfer from donors to acceptors, and this tunability can be used to enhance the shelf-life of QD based opto-electronic and photovoltaic devices.
Elasticity of two-dimensional crystals of polydisperse hard disks near close packing: Surprising behavior of the Poisson's ratio
Authors: Tretiakov Konstantin V. , Wojciechowski Krzysztof W.
Published: May 2012

The equation of state, elastic constants, and Poisson's ratio of a crystalline two-dimensional polydisperse hard disk system were determined in the close packing limit. Monte Carlo simulations in the NpT ensemble with variable shape of the periodic box reveal that the pressure and elastic constants grow with increasing polydispersity. The equation of state and the bulk modulus are well described by the free volume approximation. The latter approximation fails, however, for the shear modulus. The simulations also show that the introduction of any amount of size polydispersity in the hard disk systems causes a discontinuous “jump” of the Poisson's ratio in the close packing limit from the value νδ=0 = 0.1308(22), obtained for equidiameter hard disks, to νδ>0 ≈ 1, estimated for the polydisperse disks.
Resistive switching properties of amorphous Pr0.7Ca0.3MnO3 films grown on indium tin oxide/glass substrate using pulsed laser deposition method
Authors: Seong Tae-Geun , Bum Choi Kyu , Seo In-Tae , Oh Joon-Ho , Won Moon Ji , Hong Kwon , Nahm Sahn
Published: May 2012

Amorphous Pr0.7Ca0.3MnO3 (APCMO) films, which were grown on indium tin oxide (ITO)/glass at room temperature (RT), were n-type materials. The APCMO/ITO/glass device exhibited an average transparency of 77% in the visible range with a maximum transparency of 84% at a wavelength of 530 nm. The Pt/APCMO/ITO device showed stable bipolar resistive switching behavior over 200 cycles that did not degrade after 105 s at RT. The resistance of the APCMO film decreased in both low- and high-resistance states with increasing device area. The resistive switching behavior of the Pt/APCMO/ITO device can be explained by the trap-charged space-charge-limited current mechanism.
Near-field artifacts in tip-enhanced Raman spectroscopy
Authors: Ramos R. , Gordon M. J.
Published: May 2012

We demonstrate that near-field optical interactions encountered in tip-enhanced Raman spectroscopy (TERS) imaging of a nano-object can result in enhanced light scattering that is not caused by localized plasmonic excitations. The true TERS signal is shown to scale with the tip size; however, other tip-related artifacts can lead to spatial variations in Rayleigh and Raman scattering below the diffraction limit with decay lengths up to 250 nm. Such artifacts have been attributed to multiple scattering events involving the tip shaft; experimental considerations to alleviate these near-field artifacts and anomalous TERS signals are also discussed.
Knowing the people planning: measuring change in mental health services
Authors: Henneker Kim E. , Reed Kirk
Published: May 2012

This article describes the underlying philosophy of knowing the people planning (KPP) and gives an example of a practical approach to measure people’s recovery in terms of consumer identified outcomes leading to the improvement in the effectiveness of mental health and addiction services in Hawke’s Bay. KPP provided a valuable approach to planning service delivery by measuring key variables of service delivery based on consumer determined key features and a means to describe the quality improvements implemented in services in Hawke’s Bay. Practitioners were directly involved; the key was to identify gaps and work with stakeholders to create solutions to facilitate better and improved recovery outcomes.

What is known about the topic?
Outcomes specifically related to the effect of recovery oriented mental health services on the population, are not widely measured. Within the current health environment, it is essential outcomes are described and measured in terms of the effect on the population and the outcomes related to sustaining people’s recovery from mental illness. The purpose of the KPP approach is to provide evidence for change in service delivery and to determine if enhanced investment is making any differences to the end product experienced by consumers accessing services in terms of recovery outcomes. KPP outcome data are designed to enable services to effectively plan for and fund services to make a practical difference to those who access them.

What does this paper add?
KPP provides a framework and approach to measure consumer desired outcomes that make a practical difference to consumers lives such as paid employment; housing; social support; and access to primary healthcare. This article provides an example of KPP in action that led to significant changes which enabled services to better meet consumer needs.

What are the implications for practitioners?
KPP is a simple and effective tool that enables quantitative data to be collected and analysed. Practitioners contribute to data collection and the data can then be used to directly affect service design and investment. The KPP process allows practitioners to know the people they are working with and to identify and address consumer needs, which in turn leads to an improved service, creating a more satisfying working environment. KPP also develops a means to measure the effectiveness of practice.
Validity of anaesthetic complication coding data as a clinical indicator
Authors: Jones Andrew , Monagle John P. , Peel Susan , Coghlan Matthew W. , Malkoutzis Vangy , Groom Andrea
Published: May 2012

Clinical indicators using routinely collected International Statistical Classification of Diseases, Australian Modification (ICD–10–AM) data offer promise as tools for improvement of quality. The ICD–10–AM is the coding system used by Australian administrators to summarise information from the clinical record to describe a patient’s hospital encounter. The use of anaesthesia complications as coded by this system has been proposed by two jurisdictions as a monitor of the quality of anaesthetic services. We undertook a review of cases identified by such indicators in a large tertiary hospital. Our results indicate the anaesthesia indicator dataset proposed by the Victorian and Queensland Health departments appears to have little clinical or quality improvement relevance. What is known about the topic? Quality assurance relies on reviewing performance, highlighting issues and eliminating or minimising the identified risks. Case or risk identification in the medical arena relies heavily on self reporting, which has many flaws. A system not dependent on self reporting that was reliable would be a positive development in the pursuit of quality improvement. What does this paper add? ICD-AM-10 coding was used to identify complications attributable to anaesthesia as defined by the coding system. The cases identified were then reviewed for the clinical accuracy of this information. The clinical coding was accurate, but the clinical case load so identified did not accurately reflect real incidents of anaesthesia-related complications. The ICD AM 10 codes, as they relate to anaesthesia complications, do not provide a reliable method of identifying cases that contribute to anaesthetic quality assurance activities. What are the implications for practitioners? Anaesthesia quality assurance continues to be dependent on self reporting of relevant cases. Coded data do not provide an adequate substitute for the self reporting mechanisms.
Contrasts in Habitat Characteristics and Life History Patterns of Oncorhynchus mykiss in California's Central Coast and Central Valley
Authors: Sogard Susan M. , Merz Joseph E. , Satterthwaite William H. , Beakes Michael P. , Swank David R. , Collins Erin M. , Titus Robert G. , Mangel Marc
Published: May 2012

Oncorhynchus mykiss exhibit high plasticity in their life history patterns. Individual life history decisions are hypothesized to result from genetic thresholds shaped by local adaptation, with variation in environmental factors influencing the trajectories of growth and condition (e.g., Fulton's K, lipid content). We compared growth rates and life history patterns in two coastal creeks (Scott and Soquel) and two Central Valley (CV) rivers (American and Mokelumne) in California. The two regions differed markedly in habitat and physical factors, including hydrograph timing and amplitude, temperature regime, and food availability (measured as drift). Growth rates of coastal age‐0 fish averaged 0.1 mm/d in summer–fall and 0.2 mm/d in winter–spring. Growth rates of CV fish were up to 10 times faster than those of fish on the coast and had the opposite seasonal pattern, in which growth in summer–fall was faster than that in winter–spring. Fish growth also differed between CV rivers; the mean growth rates were 1.0 mm/d in summer–fall and 0.7 mm/d in winter–spring among American River fish and 0.7 mm/d in summer–fall and 0.5 mm/d in winter–spring among Mokelumne River fish. The life history expression and age structures of O. mykiss in the coastal creeks were similar, with populations being dominated by age‐0 fish but including mature residents up to age 6. The two CV populations were strikingly different in life history expression. In the American River, a single cohort was present and nearly all fish emigrated in the spring following their birth year. In the Mokelumne River, a broad diversity of ages (up to 4 years) was present, with a large proportion of presumed residents. The observed variation in life histories aligned with predictions based on state‐dependent life history models developed for the four streams, further demonstrating the adaptability of O. mykiss to contrasting rearing environments.
Deaf and hearing children's plural noun spelling
Authors: Breadmore Helen L. , Olson Andrew C. , Krott Andrea
Published: May 2012

The present study examines deaf and hearing children's spelling of plural nouns. Severe literacy impairments are well documented in the deaf, which are believed to be a consequence of phonological awareness limitations. Fifty deaf (mean chronological age 13;10 years, mean reading age 7;5 years) and 50 reading-age-matched hearing children produced spellings of regular, semiregular, and irregular plural nouns in Experiment 1 and nonword plurals in Experiment 2. Deaf children performed reading-age appropriately on rule-based (regular and semiregular) plurals but were significantly less accurate at spelling irregular plurals. Spelling of plural nonwords and spelling error analyses revealed clear evidence for use of morphology. Deaf children used morphological generalization to a greater degree than their reading-age-matched hearing counterparts. Also, hearing children combined use of phonology and morphology to guide spelling, whereas deaf children appeared to use morphology without phonological mediation. Therefore, use of morphology in spelling can be independent of phonology and is available to the deaf despite limited experience with spoken language. Indeed, deaf children appear to be learning about morphology from the orthography. Education on more complex morphological generalization and exceptions may be highly beneficial not only for the deaf but also for other populations with phonological awareness limitations.