bluuebunny/crossref_metadata_2025 huggingface dataset:
Laterality, hand control and scholastic performance: a British birth cohort study
Authors: Björk Tabita , Brus Ole , Osika Walter , Montgomery Scott
Published: March 2012

Objectives

To use simple measures of laterality and hand control that can identify a greater risk of poorer scholastic ability, potentially signalling suboptimal hemispheric lateralisation.

Design

Analysis of material from a birth cohort study.

Setting

Members of the National Child Development Study, a British birth cohort study following people born in 1958.

Participants

10 612 children who undertook tests at age 11 years.

Primary outcome measures

Teacher-administered tests of non-verbal general ability, verbal general ability, reading comprehension and mathematics.

Results

Linear regression produced associations (and 95% CIs) with tests of verbal general ability, non-verbal general ability, reading comprehension and mathematics scores for the lowest third (compared with highest) of a left-hand control test involving picking up matches of −1.21 (−1.73 to −0.68; p<0.001), −0.72 (−1.14 to −0.29; p=0.001), −0.70 (−1.06 to −0.35; p<0.001) and −1.32 (−1.90 to −0.73; p<0.001). Among those in the lowest third of the right-hand control test score, mixed-handedness compared with right-handedness was associated with poorer scholastic performance, with regression coefficients (and 95% CIs; p values) of 1.90 (−3.01 to −0.80; p=0.001), −1.25 (−2.15 to −0.35; p=0.007), −1.28 (2.04 to −0.53; p=0.001) and −1.33 (−2.53 to −0.13; p=0.030). The estimates are for a point change in the scholastic test scores, after adjustment for sex, left-hand motor function and social class. Statistically significant associations with mixed-handedness were only observed for the lowest third of right-hand motor function.

Conclusions

Measures involving poorer left-hand motor function may represent useful markers of reduced cognitive function possibly reflecting suboptimal hemispheric lateralisation. Crude measures of laterality such as reported non-right-handedness may be more useful for research when combined with measures of motor function.
Track and trigger in an emergency department: an observational evaluation study
Authors: Wilson Sarah J , Wong David , Clifton David , Fleming Susannah , Way Rob , Pullinger Richard , Tarassenko Lionel
Published: March 2012

Objective

To evaluate the utilisation of paper-based track and trigger (T&T) charts in a UK emergency department (ED).

Methods

A single-centre prospective observational cohort study was conducted in the ED of a medium-sized teaching hospital. Charted vital-sign data were collected from adults attending the resuscitation room, majors or observation ward. These data were examined in parallel with clinical notes to identify ‘escalation’ events. For each set of vital signs, the authors calculated the T&T score retrospectively.

Results

Data from 472 patient episodes (2965 sets of vital signs) were examined. 85.8% of patients had at least one full set of observations (CEM standard) and 60.6% had at least one T&T score documented. However, only 34.5% of observation sets had a corresponding T&T score. 20.6% of T&T score totals (1024) were incorrect, potentially preventing a ‘trigger’ from being recognised. 204 patient episodes had at least one recorded escalation. Physiological escalations were associated with vital-sign scores that met the triggering thresholds (98/104), while patients who had non-physiological escalations or no escalations were more likely to have scores below the triggering thresholds (88/100). Only 26.9% of physiological escalations were associated with a documented T&T score above the triggering threshold. Retrospective completion of the charts increased that figure to 94.2%.

Conclusion

T&T in the ED is challenged by poor completion rates and numerical errors made during score calculation. However the potential for recognition of a deteriorating patient should not be ignored. The future work of the authors intends to evaluate an electronic system for automatically calculating T&T scores within the ED environment.
A case of epididymitis associated with Panton–Valentine leukocidinStaphylococcus aureus
Authors: Raychaudhuri Malini , Chew Pei Ru
Published: March 2012

A new pattern of disease caused by Panton–Valentine leukocidin (PVL)-positive strains ofStaphylococcus aureusis emerging in the UK and worldwide. Community-associated methicillin-resistantS aureus(MRSA) is more likely to produce PVL, a pore-forming cytotoxin inducing leucocyte lysis, which often infects young healthy individuals. The worldwide emergence and continually increasing prevalence of community-acquired PVL–MRSA have recently attracted high-profile media attention and prompted concern regarding the transmissibility and virulence. This paper reports a case of genitourinary tract infection associated with PVL-positive community-associated MRSA in an immunocompetent young man.
CUNTZ–PIMSNER ALGEBRAS FOR SUBPRODUCT SYSTEMS
Authors: VISELTER AMI
Published: March 2012

In this paper we generalize the notion of Cuntz–Pimsner algebras of C*-correspondences to the setting of subproduct systems. The construction is justified in several ways, including the Morita equivalence of the operator algebras under suitable conditions and examples are provided to illustrate its naturality. We also demonstrate why some features of the Cuntz–Pimsner algebras of C*-correspondences fail to generalize to our setting, and discuss what we have instead.
ENTROPIC-GRAVITY DERIVATION OF MOND
Authors: KLINKHAMER F. R.
Published: March 2012

A heuristic entropic-gravity derivation has previously been given of the gravitational two-body force of modified Newtonian dynamics (MOND). Here, it is shown that another characteristic of MOND can also be recovered, namely, the external field effect (implying a violation of the Strong Equivalence Principle). In fact, the derivation gives precisely the modified Poisson equation which Bekenstein and Milgrom proposed as a consistent nonrelativistic theory of MOND.
BEYOND THE MINIMAL SUPERSYMMETRIC STANDARD MODEL: FROM THEORY TO PHENOMENOLOGY
Authors: FUKS BENJAMIN
Published: March 2012

Thanks to the latest development in the field of Monte Carlo event generators and satellite programs allowing for a straightforward implementation of any beyond the Standard Model theory in those tools, studying the property of any softly-broken supersymmetric theory is become an easy task. We illustrate this statement in the context of two nonminimal supersymmetric theories, namely the Minimal Supersymmetric Standard Model with R-parity violation and the Minimal R-symmetric Supersymmetric Standard Model and choose to probe interaction vertices involving a nonstandard color structure and the sector of the top quark. We show how to efficiently implement these theories in the MATHEMATICA package FEYNRULES and use its interfaces to Monte Carlo tools for phenomenological studies. For the latter, we employ the latest version of the MADGRAPH program.
SYNCHROTRON RADIATION INSIDE A DIELECTRIC CYLINDER
Authors: SAHARIAN A. A. , KOTANJYAN A. S.
Published: March 2012

We investigate the electromagnetic fields generated by a charged particle rotating inside a dielectric cylinder immersed into a homogeneous medium. The expressions for the bound modes of the radiation field are derived in both interior and exterior regions. The radiation intensity for the modes propagating inside the cylinder is evaluated by using two different ways: by evaluating the work done by the radiation field on the charge and by evaluating the energy flux through the cross-section of the cylinder. The relation between these two quantities is discussed. We investigate the relative contributions of the bound modes and the modes propagating at large distances from the cylinder to the total radiation intensity. Numerical examples are given for a dielectric cylinder in the vacuum. It is shown that the presence of the cylinder can lead to the considerable increase of the synchrotron radiation intensity.
MELTING CURVE OF SEMICONDUCTORS WITH DEFECTS: PRESSURE DEPENDENCE
Authors: HUNG VU VAN , THANH LE DAI
Published: March 2012

The high-pressure melting curve of semiconductors with defects has been studied using statistical moment method (SMM). In agreement with experiments and with DFT calculations we obtain a negative slope for the high-pressure melting curve. We have derived a new equation for the melting curve of the defect semiconductors. The melting was investigated at different high pressures, and the SMM calculated melting temperature of Si, AlP, AlAs and GaP crystals with defects being in good agreement with previous experiments.
TOPOLOGY OF ENTANGLEMENT EVOLUTION OF TWO QUBITS
Authors: ZHOU DONG , CHERN GIA-WEI , FEI JIANJIA , JOYNT ROBERT
Published: March 2012

The dynamics of a two-qubit system is considered with the aim of a general categorization of the different ways in which entanglement can disappear in the course of the evolution, e.g., entanglement sudden death. The dynamics is described by the function n(t), where n is the 15-dimensional polarization vector. This representation is particularly useful because the components of n are direct physical observables, there is a meaningful notion of orthogonality, and the concurrence C can be computed for any point in the space. We analyze the topology of the space S of separable states (those having C = 0), and the often lower-dimensional linear dynamical subspace D that is characteristic of a specific physical model. This allows us to give a rigorous characterization of the four possible kinds of entanglement evolution. Which evolution is realized depends on the dimensionality of D and of D∩S, the position of the asymptotic point of the evolution, and whether or not the evolution is "distance-Markovian", a notion we define. We give several examples to illustrate the general principles, and to give a method to compute critical points. We construct a model that shows all four behaviors.
KAPPA-DEFORMED RANDOM-MATRIX THEORY BASED ON KANIADAKIS STATISTICS
Authors: ABUL-MAGD A. Y. , ABDEL-MAGEED M.
Published: March 2012

We present a possible extension of the random-matrix theory, which is widely used to describe spectral fluctuations of chaotic systems. By considering the Kaniadakis non-Gaussian statistics, characterized by the index κ (Boltzmann–Gibbs entropy is recovered in the limit κ → 0), we propose the non-Gaussian deformations (κ ≠ 0) of the conventional orthogonal and unitary ensembles of random matrices. The joint eigenvalue distributions for the κ-deformed ensembles are derived by applying the principle maximum entropy to Kaniadakis entropy. The resulting distribution functions are base invariant as they depend on the matrix elements in a trace form. Using these expressions, we introduce a new generalized form of the Wigner surmise valid for nearly-chaotic mixed systems, where a basis-independent description is still expected to hold. We motivate the necessity of such generalization by the need to describe the transition of the spacing distribution from chaos to order, at least in the initial stage. We show several examples about the use of the generalized Wigner surmise to the analysis of the results of a number of previous experiments and numerical experiments. Our results suggest the entropic index κ as a measure for deviation from the state of chaos. We also introduce a κ-deformed Porter–Thomas distribution of transition intensities, which fits the experimental data for mixed systems better than the commonly-used gamma-distribution.
DATA SET MODELS AND EXPONENTIAL FAMILIES IN STATISTICAL PHYSICS AND BEYOND
Authors: NAUDTS JAN , ANTHONIS BEN
Published: March 2012

The exponential family of models is defined in a general setting, not relying on probability theory. Some results of information geometry are shown to remain valid. Exponential families both of classical and of quantum mechanical statistical physics fit into the new formalism. Other less obvious applications are predicted. For instance, quantum states can be modeled as points in a classical phase space and the resulting model belongs to the exponential family.
EXACT COLEMAN–DE LUCCIA INSTANTONS
Authors: KANNO SUGUMI , SODA JIRO
Published: March 2012

We present exact Coleman–De Luccia (CDL) instantons, which describe vacuum decay from Anti-de Sitter (AdS) space, de Sitter (dS) space and Minkowski space to AdS space. We systematically obtain these exact solutions by considering deformation of Hawking-Moss (HM) instantons. We analytically calculate the action of instantons and discuss a subtlety in calculation of decay rates.
DYNAMICS ON A HOLLING II PREDATOR–PREY MODEL WITH STATE-DEPENDENT IMPULSIVE CONTROL
Authors: LIU BING , TIAN YE , KANG BAOLIN
Published: March 2012

According to biological and chemical control strategy for pest control, a Holling II functional response predator–prey system concerning state-dependent impulsive control is investigated. We define the successor functions of semi-continuous dynamic system and give an existence theorem of order 1 periodic solution of such a system. By means of sequence convergence rules and qualitative analysis, we successfully get the conditions of existence and attractiveness of order 1 periodic solution. Our results show that our method used in this paper is more efficient and easier than the existing methods to prove the existence and attractiveness of order 1 periodic solution.
OPTIMAL CONTROL FOR A NONLINEAR n-DIMENSIONAL COMPETING SYSTEM WITH AGE-STRUCTURE
Authors: LUO ZHI-XUE , YANG JIAN-YU , LUO YA-JUAN
Published: March 2012

This paper is concerned with optimal harvesting control of a first order partial differential equation system representing a nonlinear n-dimensional competitive population model with age-structure. By the Ekeland's variational principle, the existence and unique characterization of the optimal control strategy are established. The optimality conditions for the control problem are obtained by the concept of the normal cone.
TRANSMISSION DYNAMICS AND OPTIMAL CONTROL OF AN INFLUENZA MODEL WITH QUARANTINE AND TREATMENT
Authors: SHI WEI-WEI , TAN YUAN-SHUN
Published: March 2012

We develop an influenza pandemic model with quarantine and treatment, and analyze the dynamics of the model. Analytical results of the model show that, if basic reproduction number [Formula: see text], the disease-free equilibrium (DFE) is globally asymptotically stable, if [Formula: see text], the disease is uniformly persistent. The model is then extended to assess the impact of three anti-influenza control measures, precaution, quarantine and treatment, by re-formulating the model as an optimal control problem. We focus primarily on controlling disease with a possible minimal the systemic cost. Pontryagin's maximum principle is used to characterize the optimal levels of the three controls. Numerical simulations of the optimality system, using a set of reasonable parameter values, indicate that the precaution measure is more effective in reducing disease transmission than the other two control measures. The precaution measure should be emphasized.
Crystallization Using Biomineralized Nickel Nanodots of Amorphous Silicon Thick Films Deposited by Chemical Vapor Deposition, Sputtering and Electron Beam Evaporation
Authors: Nishida Takashi , Fuse Kazushi , Furuta Mamoru , Ishikawa Yasuaki , Uraoka Yukiharu
Published: March 2012

The fabrication of polycrystalline silicon (poly-Si) films by metal-induced lateral crystallization (MILC) using biomineralized Ni nanodots was investigated. The dependence of film crystallinity on the deposition method for the amorphous Si precursor films, such as plasma-enhanced chemical vapor deposition (PECVD), sputtering deposition, or electron beam evaporation, was evaluated. The preparation of thick films and their crystallization are discussed. The poly-Si film obtained by CVD had a large residual stress (1.4 GPa). In contrast, the stress of the sputtered film was very low and had firm adherence to the substrate. Thus, Si films over 1 µm thick can be easily prepared by sputtering; however, the crystallite size in the films is very small because crystallization is prevented by a high-density of impurities in the sputtered films. Therefore, the preparation of poly-Si films with adhesion layers was attempted by CVD. Si films thicker than 100 nm without an adhesion layer were exfoliated from the substrates. Poly-Si films of 270 nm thick with large crystallite sizes above 20 µm were prepared with an adhesion layer using the CVD method, and the concentrations of impurities, such as carbon and Ni, in the obtained CVD film were very low.
Crystallization of Si Thin Film on Flexible Plastic Substrate by Blue Multi-Laser Diode Annealing
Authors: Okada Tatsuya , Mugiraneza Jean de Dieu , Shirai Katsuya , Suzuki Toshiharu , Noguchi Takashi , Matsushima Hideki , Hashimoto Takao , Ogino Yoshiaki , Sahota Eiji
Published: March 2012

Si thin film coated on a flexible polyimide (PI) substrate was successfully crystallized by blue multi-laser diode annealing (BLDA) in the CW mode. The precursor Si film of 50 nm thickness was stably deposited at room temperature using a radio-frequency (RF) sputtering machine. Subsequently, a blue (445 nm) laser beam of 1.1 W was irradiated onto the Si film at a scan speed of 500 mm/s. After irradiation, neither damage to the substrate nor degradation of the Si film surface was observed, and the Si surface was kept smooth within 4.2 nm (RMS). By Raman peak shift at 520 cm-1 and transmission electron microscope (TEM) observation, the crystalline fraction of 100% was estimated in spite of the presence of micro-grains of ∼50 nm in diameter. The BLDA allows the realization of ultra-low temperature polycrystalline silicon (poly-Si) and is suitable for the next-generation system on panel (SoP).
Surface Passivation of Crystalline Silicon by Combination of Amorphous Silicon Deposition with High-Pressure H2O Vapor Heat Treatment
Authors: Sameshima Toshiyuki , Nagao Tomokazu , Hasumi Masahiko , Shuku Asuka , Takahashi Eiji , Andoh Yasunori
Published: March 2012

A high minority carrier effective lifetime τeff of crystalline silicon was achieved by hydrogenated amorphous silicon (a-Si:H) films formed by a combination of plasma-enhanced chemical vapor deposition at 150 °C with high-pressure H2O vapor heat treatment. τeff was 1.6×10-4, 3.0×10-4, and 1.15×10-3 s for n-type silicon substrates coated with 3-, 10-, and 50-nm-thick a-Si:H films treated with 1.0×106 Pa H2O vapor heat treatment between 180 and 300 °C for 1 h. Light-induced passivation enhancement was demonstrated when 620-nm light was illuminated at the 50-nm-thick a-Si:H surface. τeff increased from 8.5×10-4 to 1.15×10-3 s probably caused by field effect passivation induced by hole trapping at the SiO
x
formed by H2O vapor heat treatment for 1 h. On the other hand, τeff was further increased to 1.2×10-3 s by 1.0×106 Pa H2O vapor heat treatment at 300 °C for 3 h for the sample formed with the 50-nm-thick a-Si:H film. However, no increase in τeff was observed by light illumination at the a-Si:H surface, probably because the SiO
x
clusters became stable and had no hole trapping property.
Large-Area Thin-Film Silicon: Synergy between Displays and Solar Cells
Authors: Schropp Ruud E. I.
Published: March 2012

Thin-film silicon technology has changed our society, owing to the rapid advance of its two major application fields in communication (thin-film displays) and sustainable energy (thin-film solar cells). Throughout its development, advances in these application fields have always benefitted each other. In the 1980s, display technology benefitted from the know-how on plasma deposition and equipment intended for solar cells. In the 2000s, thin-film solar technology benefitted from the scaled-up versions of plasma deposition equipment, and presently Gen5 or Gen5.5 is the most commonly used size for thin-film solar modules. Scaling has always been the major cost driver for displays. For solar cells, the cost per installed watt is another important factor, and therefore primary attention for sustained growth in photovoltaics should be given to cell efficiency.
Channel Shortening Phenomenon Due to Redox Reaction in a Lateral Direction on In–Ga–Zn–O Thin Film Transistors
Authors: Kitakado Hidehito , Katoh Sumio
Published: March 2012

We investigated low-resistivity regions in In–Ga–Zn–O layer formed by a redox reaction during post-passivation annealing. The low-resistivity regions formed inside the source and drain electrodes significantly affect the performance parameters of a thin film transistor (TFT), such as the electrically effective channel length and the external resistance of TFT channels. The TFT performance parameters depend on the gate voltage because the low-resistivity regions exhibit a gradual carrier distribution. We approximated the distributions using a function derived from the diffusion equation by fitting the calculated resistance to the measured resistance for several channel lengths. In addition, we acquired the diffusion coefficients for different annealing temperatures from distribution functions. The activation energy of the diffusion coefficients suggest that hydrogen diffusion results in the formation of the low-resistivity region by a reduction reaction in the In–Ga–Zn–O film.
Low-Operating-Voltage Solution-Processed InZnO Thin-Film Transistors Using High-k SrTa2O6
Authors: Lu Li , Miura Yuta , Nishida Takashi , Echizen Masahiro , Ishikawa Yasuaki , Uchiyama Kiyoshi , Uraoka Yukiharu
Published: March 2012

In this research, an InZnO channel layer and a high-k SrTa2O6 gate insulator were both fabricated using a solution process for the application of thin film transistors (TFTs). A low turn-on voltage of -1.2 V, a low threshold voltage of 0.8 V, a high on/off current ratio of 5×106 at a low voltage of 5 V, and a saturation mobility of 0.24 cm2/(V·s) were obtained. The diffusion of oxygen from the high-k SrTa2O6 gate insulator to the InZnO channel layer through the interface was effective for decreasing the concentration of impurities in solution-processed InZnO TFTs and subsequently enhancing mobility. Furthermore, a very low subthreshold swing value of 0.1 V/decade was obtained. This low value was due to the very smooth surface and the voltage-independent high dielectric constant of 36 for the SrTa2O6 thin film.
Fabrication of Defect-Free Ferroelectric Liquid Crystal Cells Using Alignment Films Rubbed in Antiparallel Direction
Authors: Furue Hirokazu , Abe Masamichi
Published: March 2012

The fabrication of operable surface-stabilized ferroelectric liquid crystals (SSFLCs) is often hampered by the occurrence of zigzag defects. In this study, we try to fabricate a defect-free SSFLC with antiparallel-rubbed films that exhibit different properties between two substrates for the energy condition in two types of chevron to be different. As a result, the occurrence of zigzag defects can be suppressed as the differences in anchoring strength and pretilt angle increase between two alignment films, and then in the case of the large differences in physical properties, zigzag defect-free SSFLCs can be obtained.
Size Control of ZnS Nanoparticles by Electro-Spray Deposition Method
Authors: Doe Takahiro , Ishikawa Yasuaki , Horita Masahiro , Nishida Takashi , Uraoka Yukiharu
Published: March 2012

Zinc sulfide (ZnS) semiconductor nanoparticles were prepared by electro-spray deposition (ESD) method. ESD method is a particle preparation process via the spray pyrolysis route, in which droplets are generated at the nozzle tip in combination with the evaporation of the solvent in the droplets. We fabricated nanoparticles whose sizes were controlled to the single-digit nanometer scale through precise control of the applied voltage and nozzle tip diameter. We successfully obtained nanoparticles whose sizes were 9.7 nm on average and with 3.1 nm full-width half-maximum of the distribution after optimizing the nozzle tip diameter and the applied voltage. We also confirmed that the obtained nanoparticles had the wurtzite structure of ZnS, and the inside consisted of a single crystal phase according to the X-ray diffraction measurements and the high-resolution transmission electron microscope images.
Threshold-Voltage-Shift Compensation and Suppression Method Using Hydrogenated Amorphous Silicon Thin-Film Transistors for Large Active Matrix Organic Light-Emitting Diode Displays
Authors: Oh Kyonghwan , Kwon Oh-Kyong
Published: March 2012

A threshold-voltage-shift compensation and suppression method for active matrix organic light-emitting diode (AMOLED) displays fabricated using a hydrogenated amorphous silicon thin-film transistor (TFT) backplane is proposed. The proposed method compensates for the threshold voltage variation of TFTs due to different threshold voltage shifts during emission time and extends the lifetime of the AMOLED panel. Measurement results show that the error range of emission current is from -1.1 to +1.7% when the threshold voltage of TFTs varies from 1.2 to 3.0 V.
Novel Driving Method for Two-Dimensional and Three-Dimensional Switchable Active Matrix Organic Light-Emitting Diode Displays for Emission and Programming Time Extension
Authors: In Hai-Jung , Kwon Oh-Kyong
Published: March 2012

A novel driving method for two-dimensional (2D) and three-dimensional (3D) switchable active matrix organic light-emitting diode (AMOLED) displays is proposed to extend emission time and data programming time during 3D display operation. The proposed pixel consists of six thin-film transistors (TFTs) and two capacitors, and the aperture ratio of the pixel is 45.8% under 40-in. full-high-definition television condition. By increasing emission time and programming time, the flicker problem can be reduced and the lifetime of AMOLED displays can be extended owing to the decrease in emission current density. Simulation results show that the emission current error range from -0.4 to 1.6% is achieved when the threshold voltage variation of driving TFTs is in the range from -1.0 to 1.0 V, and the emission current error is 1.0% when the power line IR-drop is 2.0 V.
High Hole Mobility in GaAs1-xBix Alloys
Authors: Kado Kosuke , Fuyuki Takuma , Yamada Kazuya , Oe Kunishige , Yoshimoto Masahiro
Published: March 2012

A hole mobility of ∼200 cm2 V-1 s-1 was demonstrated for GaAs1-x
Bi
x
(x ≤4%). This value is comparable to that of GaAs with the same hole concentration. The hole mobility of GaAs1-x
Bi
x
(x ≈5%) degrades, but is still larger than the reported values for GaAs1-x
Bi
x
. Despite concerns regarding the degradation of hole mobility in GaAs1-x
Bi
x
due to scattering at Bi-related localized states near the valence band, p-type GaAs1-x
Bi
x
was able to be obtained without degradation of hole mobility. This is probably owing to the surfactant effect of the bismuth atoms during growth.
Light Source Position Dependence of Evanescent Wave Coupling Effect in Narrow GaAs/AlGaAs Ridge Structure
Authors: Wang Xue-Lun , Takahashi Tokio
Published: March 2012

The light source position dependence of the evanescent wave coupling effect in a sub-wavelength-sized GaAs/AlGaAs ridge structure was investigated using the theoretical simulation and temperature-dependent emission pattern measurements. It was found that the evanescent wave coupling effect could be realized for a light source located at any position of the top-flat quantum well (QWL), although the emissions transformed from evanescent waves began to get emitted in directions that formed an increasingly larger angle with respect to the surface normal of the ridge flat facet when the light source was moved from the center to the edge of the flat QWL.
First-Principles Study on Intrinsic Point Defects in Rhombohedral LaAlO3 and Their Effects on Electrical Properties
Authors: Xie Xiaojun , Cheng Yonghong , Xiao Bing , Ohki Yoshimichi
Published: March 2012

Formation energies and energy levels of various neutral and charged defects in bulk rhombohedral LaAlO3 are calculated numerically in different equilibrium conditions under different oxygen partial pressures, using first-principles plane-wave calculations. The roles of such defects in electrical properties of LaAlO3 are also discussed. The results obtained by calculations show that the formation energy becomes low for oxygen interstitial if LaAlO3 is in an oxygen-rich condition. In contrast, an oxygen vacancy is easily formed in a condition where oxygen is deficient and metal elements are relatively rich, even if the oxygen partial pressure is high. These results explain well the concentration change of constituent elements in LaAlO3 under different treatment atmospheres. Furthermore, the calculations can interpret a large tunnelling current that is often observed in a metal–oxide–silicon structure using LaAlO3 as the oxide layer, since the O vacancy has an energy level near the valence band maximum of Si.
Low-Loss GaInAsP Wire Waveguide on Si Substrate with Benzocyclobutene Adhesive Wafer Bonding for Membrane Photonic Circuits
Authors: Lee Jieun , Maeda Yasuna , Atsumi Yuki , Takino Yuta , Nishiyama Nobuhiko , Arai Sigehisa
Published: March 2012

Low-power and compact optical interconnects can be realized using III–V membrane photonic integrated circuits fabricated from thin InP-based films bonded to a Si wafer using benzocyclobutene (BCB) adhesive wafer bonding method. However, the conditions of the bonding and fabrication process strongly affect the propagation loss of waveguides. This study investigated the process conditions during bonding and waveguide fabrication with a view to reducing the propagation loss. It was found that clean, large GaInAsP thin films without air voids or fractures could be obtained by using an appropriate solvent volatilization time of 20–30 min at 200 °C for BCB. Furthermore, by using a resist with high dry etching resistance and an SiO2 mask for the etching process, the sidewall roughness of the waveguide was significantly reduced, which finally afforded a waveguide propagation loss as low as 4 dB/cm.
Giant Field-Induced Distortion in Mn3SbN at Room Temperature
Authors: Takenaka Koshi , Shibayama Takashi , Kasugai Daiki , Shimizu Takeshi
Published: March 2012

The discovery of magnetostriction at room temperature in the antiperovskite Mn3SbN is reported herein. Mn3SbN undergoes a phase transition from a high-temperature (high-T) paramagnetic state to a low-Tferromagnetic (FM) state at the Curie temperature ofTC= 360 K, accompanied by a cubic-to-tetragonal structural deformation. In the tetragonally distorted FM phase, Mn3SbN exhibits large magnetostriction of up to 450 ppm, estimated from the linear thermal expansion under a magnetic field of 90 kOe while slowly reducing the temperature. The magnetostriction estimated by the same procedure is enhanced to 1000 ppm without reduction of the operating temperature by partial replacement of the constituent elements. The present results are examined in terms of ferromagnetic shape memory effects.
Electron Mobility Limited by Remote Charge Scattering in Thin (100)- and (110)-Oriented Silicon Body Double-Gated Metal–Oxide–Semiconductor Field-Effect Transistors with High-k Gate Dielectrics
Authors: Iijima Ryosuke , Edge Lisa F. , Paruchuri Vamsi , Takayanagi Mariko
Published: March 2012

We have investigated the electron mobility limited by the remote charge scattering, µRCS, in the thin silicon body (≤8 nm) double-gated metal–oxide–semiconductor field-effect transistors (MOSFETs), focusing on its dependency on the body thickness and the silicon surface orientation. In order to predict the µRCS in such an unprecedented MOSFET system, the adequacy of physical models used in the computation was verified by comparing the computational results with the experimentally determined µRCS from the actual bulk MOSFETs with high-k dielectric fabricated on the (100) and (110) silicon substrates. It has been discovered for the first time that the µRCS is dropped to less than half of the bulk device's µRCS when the body thickness is 5 nm and that the µRCS lowering derived from the body thickness reduction is more serious in the (110)-oriented surface than in the (100)-oriented surface. These mobility trends have been quantitatively explained by the effective mass difference between the two surfaces as well as by the carrier confinement in the metallurgically defined narrow silicon body. These observations indicate the great importance of the systematic reduction of charged traps in high-k gate dielectrics in the advanced devices.
Observation of Fine Lung Structure by Ultrahigh-Resolution Optical Coherence Tomography Using 800, 1060, and 1300 nm Supercontinua
Authors: Ishida Shutaro , Nishizawa Norihiko , Kitatsuji Masashi , Ohshima Hiroyoshi , Hasegawa Yoshinori , Matsushima Miyoko , Kawabe Tsutomu
Published: March 2012

Cross-sectional imaging of isolated rat lungs was demonstrated by ultrahigh-resolution optical coherence tomography using supercontinua at 800, 1060, and 1300 nm wavelengths. The detailed structure of the trachea, including cartilage, mucosa, and annular ligaments, were observed clearly. In the imaging of visceral pleura and alveoli, when phosphate-buffered saline was instilled into the lung, the penetration depth of imaging was improved, and clear images of the fine structure of the lung, including alveoli, were observed owing to the index-matching effect. The wavelength dependence of the light source was discussed for the observation of fine structure and imaging contrast.
X-ray Photoemission Spectroscopy Study of GaAs(111)B Substrate Nitridation using an RF-Radical Source
Authors: Naritsuka Shigeya , Mori Midori , Takeuchi Yoshitaka , Maruyama Takahiro
Published: March 2012

The mechanism of GaAs(111)B surface nitridation using an RF-radical source was studied while systematically changing the nitridation temperature. Atomic force microscopy and X-ray photoemission spectroscopy measurements indicated that the nitridation of the GaAs(111)B surface showed a similar dependence on nitridation temperature to that of a GaAs(001) surface. Both the degree of nitridation and the Ga adatom density increased with increasing nitridation temperature, and above 510 °C, Ga droplets were formed. Strong photoluminescence signals were obtained from the GaAs(111)B surfaces.
Morphodiversity, complexity and macroevolution: revealed by the megascopic life of the Palaeo-Neoproterozoic Vindhyan Supergroup, India
Authors: Srivastava Purnima
Published: March 2012

Evidence of past life found in the Vindhyan Supergroup exhibits extensive diversity and taxonomically unresolved morphological complexities indicating varied biological affinities, advanced life and macroevolutionary dynamics of evolving clades. The megascopic life of the supergroup documents possibly two macroevolutionary modes, demarcated as: (i) the Palaeo-Mesoproterozoic transitional period, which is represented by the fossil assemblages of the Semri and Rewa groups, and exhibits the domination of a diversified prokaryotic cyanobacterial community and moderately diversified megascopic life; (ii) the Neoproterozoic (Bhander groups, Uppermost Vindhyans), represented by the diversified and morphologically complex megascopic eukaryotes, and the emergence of multicellularity among plant and animal clades, viz. structures resembling bryophytes, sporophyte and Ediacara fauna. The overall Vindhyan fossils exhibit episodes of adaptive innovations and the emergence of complex morphologies in separate lineages of evolutionary history, resulting in extensive morphodiversity.

The present assemblage can be represented by that of prokaryotes, eukaryotes, possibly a symbiotic association, a
Jacutianema
-like Neoproterozoic form, specimens possibly of vaucheriacean affinity, mesoscopic intermediate forms inferred as transitional forms of microscopic–megascopic evolution, discs with process-like structures, the emergence of animal life (Ediacaran fauna) and a number of other complex morphologies that have no parallels in time and space. Traditionally and conventionally, the age of the Vindhyan Supergroup is considered to be that of Palaeoproterozoic–Neoproterozoic.
An overview of the Palaeoproterozoic geology of Peninsular India, and key stratigraphic and tectonic issues
Authors: Saha Dilip , Mazumder Rajat
Published: March 2012

The Archaean–Proterozoic rock successions in India have the potential to enrich the global database on Precambrian stratigraphic development, and to offer valuable clues to global tectonic reconstructions. Built over four distinct Archaean cratonic nuclei, the major Palaeoproterozoic supracrustal belts/cover sequences include the Dhanjori Group, the Singhbhum Group (including the Dalma volcanics and the Chandil Formation in eastern India), the Cuddapah Supergroup and the adjoining Nellore Schist Belt bordering the eastern Dharwar Craton, the Aravalli Supergroup in the Aravalli–Delhi Fold Belt in NW India, the lower Vindhyan (Semri Group) and the Mahakosal/Sausar/Betul belts close to the Central Indian Tectonic Zone (CITZ), and, possibly, the Dongargarh Supergroup in Bastar. A major erosional unconformity separates the Archaean tonalite–trondjhemite gneiss basement in these cratons from the overlying volcano-sedimentary successions. An overview of Palaeoproterozoic stratigraphic development in these cratonic blocks is presented to bring out the salient features for global comparison and to highlight issues requiring further attention. Multiple metamorphic, magmatic and deformation events are recorded in the fold belts at the join of the cratons or their margins, inviting application of the plate tectonic paradigm. However, a comprehensive tectonic model for the amalgamation of the Indian Archaean nuclei is yet to emerge, and is crucial for our understanding of Palaeoproterozoic supercontinent development.
Stability of chloritoid + biotite-bearing assemblages in some metapelites from the Palaeoproterozoic Singhbhum Shear Zone, eastern India and their implications
Authors: Sengupta Nandini
Published: March 2012

The arcuate Singhbhum Shear Zone (SSZ) of the East Indian Shield area, fringing the Archaean Singhbhum Craton, exposes a mélange-like ensemble of polymetamorphosed and highly tectonized siliciclastic sediments, mafic–ultramafic extrusive, tourmaline-rich rocks, magnetite–apatite rocks, granites and Cu–Fe–U sulphide ores of Meso- to Palaeoproterozoic age (1.5–1.77 Ga). Metapelites from two localities in the SSZ developed the enigmatic assemblage chloritoid–biotite–garnet–chlorite, which are the first reported from India and the eighth in world occurrence. Textural studies and algebraic analyses of the phase compositions in the KFMASH system indicate the operation of the reaction, chloritoid+biotite→garnet+chlorite+H
2
O and this reaction has a negative slope in pressure–temperature (
P
–
T
) space. Quantitative geothermobarometry and pseudosections in the NCMnKFMASHO system indicate that this reaction occurred during prograde metamorphism that culminated at 6.3±1 kbar and 490±40 °C. The stability of the chloritoid+biotite is also sensitive to the MnO content of the bulk rock, and to the chemical potential of H
2
O and oxygen (

μ

H

2

O

and

μ

O

2

, respectively), of the ambient fluid phase. Thrusting of continental crust in a collisional setting is invoked to explain the peak metamorphic temperatures and the clockwise
P
–
T
trajectory is construed from the petrological study of the chloritoid–biotite schist.
Preserving digital data
Authors: Goth Gregory
Published: March 2012

Scientific data is expanding at an unprecedented rate. While new tools are helping preserve this data, funding must be increased and policy coordination needs improvement.
Talking to machines
Authors: Geller Tom
Published: March 2012

Voice recognition programs like Siri are now capable of understanding spoken commands, recognizing a conversation's context, and answering questions in a personable manner.
Open for business
Authors: Hoffmann Leah
Published: March 2012

Should academic articles be available for free on the Web?
The network protocol battle
Authors: Neville-Neil George V.
Published: March 2012

A tale of hubris and zealotry.
Improving gender composition in computing
Authors: Ross Jill , Litzler Elizabeth , Cohoon J. McGrath , Sanders Lucy
Published: March 2012

Combining academic and industry representation, the NCWIT Pacesetters program works to increase the participation of girls and women in computing.
Future Tense: The deadline paradox
Authors: Clegg Brian
Published: March 2012

Future Tense, one of the revolving features on this page, presents stories and essays from the intersection of computational science and technological speculation, their boundaries limited only by our ability to imagine what could be.

Prepare for the past ahead of time.
Subcellular relocation of histone deacetylase 4 regulates growth plate chondrocyte differentiation through Ca2+/calmodulin-dependent kinase IV
Authors: Guan Yingjie , Chen Qian , Yang Xu , Haines Paul , Pei Ming , Terek Richard , Wei Xiaochun , Zhao Tingcun , Wei Lei
Published: March 2012

Regulatory mechanisms of chondrocyte differentiation in the growth plate are incompletely understood. Here, we find that histone deacetylase 4 (HDAC4) is located in the nucleus of chondrocytes in the proliferation zone and relocates to the cytoplasm of chondrocytes in the prehypertrophic zone in vivo. This suggests that the relocation of HDAC4 from the nucleus to the cytoplasm may play a role during chondrocyte differentiation. Expression of active CaMKIV in chondrocytes promotes HDAC4 relocation into cytoplasm in primary chondrocytes. Conversely, HDAC4 relocation is blocked by a Ca2+/calmodulin-dependent kinase IV (CaMKIV) inhibitor. This indicates that CaMKIV signaling plays an important role in regulating HDAC4 relocation. In addition, CaMKIV is required for HDAC4 phosphorylation, which is required for HDAC4 association with the cytoplasmic protein 14-3-3. Active CaMKIV also stimulates runt-related transcription factor-2 (RunX2) and type X collagen (Col X) promoter activities and overcomes repression of these promoter activities by HDAC4. Furthermore, CaMKIV increases gene expression of the chondrocyte differentiation markers Ihh and Col X. Our results demonstrate that CaMKIV induces chondrocyte differentiation through regulation of HDAC4 subcellular relocation, from the nucleus to the cytoplasm, which results in increased activity of RunX2 and transition of chondrocytes from the proliferative to the prehypertrophic stage. Thus, CaMKIV plays an important regulatory role during chondrocyte differentiation.
Downregulation of the CCK-B receptor in pancreatic cancer cells blocks proliferation and promotes apoptosis
Authors: Fino Kristin K. , Matters Gail L. , McGovern Christopher O. , Gilius Evan L. , Smith Jill P.
Published: March 2012

Gastrin stimulates the growth of pancreatic cancer cells through the activation of the cholecystokinin-B receptor (CCK-BR), which has been found to be overexpressed in pancreatic cancer. In this study, we proposed that the CCK-BR drives growth of pancreatic cancer; hence, interruption of CCK-BR activity could potentially be an ideal target for cancer therapeutics. The effect of CCK-BR downregulation in the human pancreatic adenocarcinoma cells was examined by utilizing specific CCK-BR-targeted RNA interference reagents. The CCK-BR receptor expression was both transiently and stably downregulated by transfection with selective CCK-BR small-interfering RNA or short-hairpin RNA, respectively, and the effects on cell growth and apoptosis were assessed. CCK-BR downregulation resulted in reduced cancer cell proliferation, decreased DNA synthesis, and cell cycle arrest as demonstrated by an inhibition of G1to S phase progression. Furthermore, CCK-BR downregulation increased caspase-3 activity, TUNEL-positive cells, and decreased X-linked inhibitor of apoptosis protein expression, suggesting apoptotic activity. Pancreatic cancer cell mobility was decreased when the CCK-BR was downregulated, as assessed by a migration assay. These results show the importance of the CCK-BR in regulation of growth and apoptosis in pancreatic cancer. Strategies to decrease the CCK-BR expression and activity may be beneficial for the development of new methods to improve the treatment for patients with pancreatic cancer.
Nesfatin-1 influences the excitability of neurons in the nucleus of the solitary tract and regulates cardiovascular function
Authors: Mimee Andrea , Smith Pauline M. , Ferguson Alastair V.
Published: March 2012

Nesfatin-1 has been identified as one of the most potent centrally acting anorexigenic peptides, and it has also been shown to play important roles in the control of cardiovascular function. In situ hybridization and immunohistochemical studies have revealed the expression of nesfatin-1 throughout the brain and, in particular, in the medullary autonomic gateway known as the nucleus of the solitary tract (NTS). The present study was thus undertaken to explore the cellular correlates and functional roles of nesfatin-1 actions in the medial NTS (mNTS). Using current-clamp electrophysiology recordings from mNTS neurons in slice preparation, we show that bath-applied nesfatin-1 directly influences the excitability of the majority of mNTS neurons by eliciting either depolarizing (42%, mean: 7.8 ± 0.8 mV) or hyperpolarizing (21%, mean: −8. 2 ± 1.0 mV) responses. These responses were observed in all electrophysiologically defined cell types in the NTS and were site specific and concentration dependent. Furthermore, post hoc single cell reverse transcriptase polymerase reaction revealed a depolarizing action of nesfatin-1 on NPY and nucleobindin-2-expressing mNTS neurons. We have also correlated these actions of nesfatin-1 on neuronal membrane potential with physiological outcomes, using in vivo microinjection techniques to demonstrate that nesfatin-1 microinjected into the mNTS induces significant increases in both blood pressure (mean AUC = 3354.1 ± 750.7 mmHg·s, n = 6) and heart rate (mean AUC = 164.8 ± 78.5 beats, n = 6) in rats. Our results provide critical insight into the circuitry and physiology involved in the profound effects of nesfatin-1 and highlight the NTS as a key structure mediating these autonomic actions.