bluuebunny/crossref_metadata_2025 huggingface dataset:
Sediment Thickness Map of the Indian Region 79°E - 86E, 2°S - 8°S Based on Satellite Gravity Interpretation
Authors: Tantrigoda Dhammika A. , Fernando M. M. P. M.
Published: October 2013

Satellite free air gravity anomalies over the Indian ocean region 79°E - 86°E, 2°S - 8°S were obtained from the website http://topex.ucsd.edu and a contour map was compiled. Five profiles of the anomaly have been interpreted in terms of two-dimensional structures in the ocean. Thickness of sediments lying on the oceanic crust determined from the interpretation of gravity profiles were used to compile an isopach map of the region 79°E-86°E, 2°S-8°S. This map in combination with one of the isopach maps compiled by previous workers, provides information regarding the thickness of sediments up to 6° S. According to this map sediment thickness varies from ∼600 m over the middle part of the region to ∼800 m further south, indicating that thinning of sediments in the middle part of the region is only localized. Information provided by this gravity study may be useful in planning detailed seismological studies to delimit the outer edge of the continental margin of Sri Lanka, defined according to the United Nations Convention of the Law of the Sea (UNCLOS).
Expression profiling of ETO2‐regulated miRNAs in erythroid cells: Possible influence on miRNA abundance
Authors: Fujiwara Tohru , Okitsu Yoko , Katsuoka Yuna , Fukuhara Noriko , Onishi Yasushi , Ishizawa Kenichi , Harigae Hideo
Published: October 2013

ETO2 is a component of a protein complex containing master regulators of hematopoiesis, including GATA‐1 and SCL/TAL1, and also has RNA binding properties. Although ETO2 has been reported to repress GATA‐1 target genes through histone deacetylation of the target gene loci in erythroid cells, little is known about the contribution of ETO2 to microRNA (miRNA) regulation. Here, we conducted miRNA profiling in ETO2‐overexpressing and ETO2‐silenced K562 cells. The analysis suggests that ETO2 positively regulates the abundance of mature miRNAs, including miR‐21, miR‐29b and let‐7e. Our data suggest a novel mode of ETO2‐mediated target gene repression via effects on miRNA expression.
Tracking Suicide Risk Factors Through Twitter in the US
Authors: Jashinsky Jared , Burton Scott H. , Hanson Carl L. , West Josh , Giraud-Carrier Christophe , Barnes Michael D. , Argyle Trenton
Published: October 2013

Background: Suicide is a leading cause of death in the United States. Social media such as Twitter is an emerging surveillance tool that may assist researchers in tracking suicide risk factors in real time. Aims: To identify suicide-related risk factors through Twitter conversations by matching on geographic suicide rates from vital statistics data. Method: At-risk tweets were filtered from the Twitter stream using keywords and phrases created from suicide risk factors. Tweets were grouped by state and departures from expectation were calculated. The values for suicide tweeters were compared against national data of actual suicide rates from the Centers for Disease Control and Prevention. Results: A total of 1,659,274 tweets were analyzed over a 3-month period with 37,717 identified as at-risk for suicide. Midwestern and western states had a higher proportion of suicide-related tweeters than expected, while the reverse was true for southern and eastern states. A strong correlation was observed between state Twitter-derived data and actual state age-adjusted suicide data. Conclusion: Twitter may be a viable tool for real-time monitoring of suicide risk factors on a large scale. This study demonstrates that individuals who are at risk for suicide may be detected through social media.
Electron energy distribution function control in gas discharge plasmas
Authors: Godyak V. A.
Published: October 2013

The formation of the electron energy distribution function (EEDF) and electron temperature in low temperature gas discharge plasmas is analyzed in frames of local and non-local electron kinetics. It is shown, that contrary to the local case, typical for plasma in uniform electric field, there is the possibility for EEDF modification, at the condition of non-local electron kinetics in strongly non-uniform electric fields. Such conditions “naturally” occur in some self-organized steady state dc and rf discharge plasmas, and they suggest the variety of artificial methods for EEDF modification. EEDF modification and electron temperature control in non-equilibrium conditions occurring naturally and those stimulated by different kinds of plasma disturbances are illustrated with numerous experiments. The necessary conditions for EEDF modification in gas discharge plasmas are formulated.
MuSTAR MD: Multi-scale sampling using temperature accelerated and replica exchange molecular dynamics
Authors: Yamamori Yu , Kitao Akio
Published: October 2013

A new and efficient conformational sampling method, MuSTAR MD (Multi-scale Sampling using Temperature Accelerated and Replica exchange Molecular Dynamics), is proposed to calculate the free energy landscape on a space spanned by a set of collective variables. This method is an extension of temperature accelerated molecular dynamics and can also be considered as a variation of replica-exchange umbrella sampling. In the MuSTAR MD, each replica contains an all-atom fine-grained model, at least one coarse-grained model, and a model defined by the collective variables that interacts with the other models in the same replica through coupling energy terms. The coarse-grained model is introduced to drive efficient sampling of large conformational space and the fine-grained model can serve to conduct more accurate conformational sampling. The collective variable model serves not only to mediate the coarse- and fine-grained models, but also to enhance sampling efficiency by temperature acceleration. We have applied this method to Ala-dipeptide and examined the sampling efficiency of MuSTAR MD in the free energy landscape calculation compared to that for replica exchange molecular dynamics, replica exchange umbrella sampling, temperature accelerated molecular dynamics, and conventional MD. The results clearly indicate the advantage of sampling a relatively high energy conformational space, which is not sufficiently sampled with other methods. This feature is important in the investigation of transition pathways that go across energy barriers. MuSTAR MD was also applied to Met-enkephalin as a test case in which two Gō-like models were employed as the coarse-grained model.
Fracture energy of polymer gels with controlled network structures
Authors: Akagi Yuki , Sakurai Hayato , Gong Jian Ping , Chung Ung-il , Sakai Takamasa
Published: October 2013

We have investigated the fracture behaviors of tetra-arm polyethylene glycol (Tetra-PEG) gels with controlled network structures. Tetra-PEG gels were prepared by AB-type crosslink-coupling of mutually reactive tetra-arm prepolymers with different concentrations and molecular weights. This series of controlled network structures, for the first time, enabled us to quantitatively examine the Lake-Thomas model, which is the most popular model predicting fracture energies of elastomers. The experimental data showed good agreement with the Lake-Thomas model, and indicated a new molecular interpretation for the displacement length (L), the area around a crack tip within which the network strands are fully stretched. L corresponded to the three times of end-to-end distance of network strands, regardless of all parameters examined. We conclude that the Lake-Thomas model can quantitatively predict the fracture energy of polymer network without trapped entanglements, with the enhancement factor being near 3.
Spontaneous electromagnetic fluctuations in unmagnetized plasmas. VI. Transverse, collective mode for arbitrary distribution functions
Authors: Felten T. , Schlickeiser R.
Published: October 2013

Using the general expressions for the magnetic fluctuation spectrum from uncorrelated plasma particles, it is shown that an isotropic, unmagnetized plasma with arbitrary momentum distribution function spontaneously emits an aperiodic, collective, transverse, damped mode. The collective mode with the dispersion relation γ(k) provides the strongest contribution to the magnetic field fluctuation spectrum. Its existence has been proven before for Maxwellian and Lorentzian plasma distribution functions. Here it is demonstrated that this collective aperiodic mode exists in any isotropic unmagnetized, irrespective of the explicit form of the momentum distribution of plasma particles.
Continuous critical current measurement of high-temperature superconductor tapes with magnetic substrates using magnetic-circuit method
Authors: Zou S. N. , Gu C. , Qu T. M. , Han Z.
Published: October 2013

The critical current (Ic) of high-temperature superconductor (HTS) tapes has to be examined not only for short samples, but also for the entire tape, because local weak points can possibly lead to the quenching of the whole HTS device. Some methods were reported for continuous Ic measurement along the length of a HTS tape, but few of them were applicable to tapes with magnetic substrates represented by \documentclass[12pt]{minimal}\begin{document}$\rm YBa_2Cu_3O_{7-\delta } (YBCO)$\end{document} YBa 2 Cu 3O7−δ( YBCO )-coated conductors based on Ni5W alloy substrate by rolling assisted bi-axially textured substrate process. We previously presented a contact-free method using magnetic circuits to measure Ic continuously of long HTS tapes, namely the magnetic-circuit (MC) method. This method has been previously applied with high speed and resolution to measure Ic of HTS tapes with non-magnetic substrates, due to its resistance to noise aroused by mechanical vibration. In this work, its ability to measure HTS tapes with magnetic substrates is demonstrated both theoretically and experimentally. A \documentclass[12pt]{minimal}\begin{document}$100 \rm m$\end{document}100m long commercial YBCO tape based on Ni5W alloy substrate was measured and regular Ic fluctuations were discovered. The MC method can be a powerful tool for quality control of HTS tapes, especially for tapes with magnetic substrates.
Spin polarization study of graphene on the Ni(111) surface by density functional theory calculations with a semiempirical long-range dispersion correction
Authors: Sun X. , Entani S. , Yamauchi Y. , Pratt A. , Kurahashi M.
Published: October 2013

The geometric and spin-resolved electronic structure of a graphene-adsorbed Ni(111) surface has been investigated by density functional theory (DFT) calculations without and with a semiempirical long-range dispersion correction (DFT-D). DFT calculations with generalized gradient approximation (GGA) functional cannot predict well about the adsorption properties of graphene to the Ni(111) surface. While DFT-D calculations with the same GGA functional give reasonable values of the adsorption energy and layer distance from graphene to the substrate. The geometry of top_fcc is the most energetically favorable in all geometries. Strong hybridization of graphene with the ferromagnetic Ni substrate induces significant shift partially in graphene π states towards the Fermi level yielding spin polarization. The spin polarization is positive at the shallow levels of modified π states and slightly negative at the deeper levels of fundamental π states, which is indicated by the calculated spin density distributions and plane-averaged density of states at the vacuum side. The opposite spin polarization is consistent with our experimental result of spin asymmetry obtained by spin-polarized metastable-atom de-excitation spectroscopy measurements.
Forward current transport mechanisms in Ni/Au-AlGaN/GaN Schottky diodes
Authors: Yan Dawei , Jiao Jinping , Ren Jian , Yang Guofeng , Gu Xiaofeng
Published: October 2013

The forward current transport mechanisms in Ni/Au-AlGaN/GaN Schottky diodes are studied by temperature dependent current-voltage (T-I-V) measurements from 298 to 473 K. The zero-bias barrier height qϕBn and ideality factor values determined based on the conventional thermionic-emission (TE) model are strong functions of temperature, which cannot be explained by the standard TE theory. Various transport models are considered to analyze the experimental I-V data. The fitting results indicate that the increased current at low bias is due to the trap-assisted tunneling with an effective trap density of about 8.8 × 106 cm−2, while the high-bias current flow is dominated by the TE transport mechanism, accompanied by a significant series resistance effect. By fitting the high-forward-bias I-V characteristics, the effective qϕBn values with a small negative temperature coefficient are obtained. The temperature dependence of the saturation tunneling current and qϕBn is finally explained by considering the thermally induced band gap shrinkage effect.
A first-principles based force-field for Li+ and OH− in ethanolic solution
Authors: Milek Theodor , Meyer Bernd , Zahn Dirk
Published: October 2013

We report on the development of force-field parameters for accurately modeling lithium and hydroxide ions in ethanol in solution. Based on quantum calculations of small molecular clusters mimicking the solvent structure of individual ions as well as the solvated LiOH dimer, significant improvements of off-the-shelf force-fields are obtained. The quality of our model is demonstrated by comparison to ab initio molecular dynamics of the bulk solution and to experimental data available for ethanol/water mixtures.
Superlattice-like Sb50Se50/Ga30Sb70 thin films for high-speed and high density phase change memory application
Authors: Hu Yifeng , Feng Xiaoyi , Li Simian , Lai Tianshu , Song Sannian , Song Zhitang , Zhai Jiwei
Published: October 2013

Multi-level phase change character of superlattice-like (SLL) Sb50Se50/Ga30Sb70 thin films was investigated through in-situ film resistance measurement. SLL structure of the thin films was confirmed by using transmission electron microscopy. Three resistance states were observed during heating process, and their thermal stability was also examined. A picosecond laser pump-probe system was used to measure phase-change time of the SLL Sb50Se50/Ga30Sb70 thin films. Phase change memory cells based on the SLL [SS(5 nm)/GS(10 nm)]3 thin films were fabricated to test and verify multi-level switch between set and reset states.
Universal scaling of correlated diffusion of colloidal particles near a liquid-liquid interface
Authors: Zhang Wei , Chen Song , Li Na , Zhang Jiazheng , Chen Wei
Published: October 2013

In this letter, we investigate the correlated diffusion of colloidal particles in quasi two-dimensional monolayer near an oil-water interface for different distance between the interface and the particle monolayer z. It is found that there is a transition in the behavior of the correlated diffusion from the bulk dominated to the interface dominated with decreasing z or increasing inter-particle separation r. With a scaling method proposed by us, the correlated diffusion can be scaled onto a master curve which captures the characters of this transition. The scale factors and the master curve allow the calculation of the distance z, which are in agreement with the one-particle measurements.
Magnetic geometry and physics of advanced divertors: The X-divertor and the snowflake
Authors: Kotschenreuther Mike , Valanju Prashant , Covele Brent , Mahajan Swadesh
Published: October 2013

Advanced divertors are magnetic geometries where a second X-point is added in the divertor region to address the serious challenges of burning plasma power exhaust. Invoking physical arguments, numerical work, and detailed model magnetic field analysis, we investigate the magnetic field structure of advanced divertors in the physically relevant region for power exhaust—the scrape-off layer. A primary result of our analysis is the emergence of a physical “metric,” the Divertor Index DI, which quantifies the flux expansion increase as one goes from the main X-point to the strike point. It clearly separates three geometries with distinct consequences for divertor physics—the Standard Divertor (DI = 1), and two advanced geometries—the X-Divertor (XD, DI > 1) and the Snowflake (DI < 1). The XD, therefore, cannot be classified as one variant of the Snowflake. By this measure, recent National Spherical Torus Experiment and DIIID experiments are X-Divertors, not Snowflakes.
Electric winds driven by time oscillating corona discharges
Authors: Drews Aaron M. , Cademartiri Ludovico , Whitesides George M. , Bishop Kyle J. M.
Published: October 2013

We investigate the formation of steady gas flows—so-called electric winds—created by point-plane corona discharges driven by time oscillating (ac) electric fields. By varying the magnitude and frequency of the applied field, we identify two distinct scaling regimes: (i) a low frequency (dc) regime and (ii) a high frequency (ac) regime. These experimental observations are reproduced and explained by a theoretical model describing the transport and recombination of ions surrounding the discharge and their contribution to the measured wind velocity. The two regimes differ in the spatial distribution of ions and in the process by which ions are consumed. Interestingly, we find that ac corona discharges generate strong electric forces localized near the tip of the point electrode, while dc corona discharges generate weaker forces distributed throughout the interelectrode region. Consequently, the velocity of the electric winds (>1 m/s) generated by ac discharges is largely independent of the position of the counter electrode. The unified theoretical description of dc and ac electric winds presented here reconciles previous observations of winds driven by dc corona and ac dielectric barrier discharges; insights from the model should also prove useful in the design of other plasma actuators.
Depolarization effects from nanoimprinted grating structures as measured by Mueller matrix polarimetry
Authors: Chen Xiuguo , Zhang Chuanwei , Liu Shiyuan
Published: October 2013

Mueller matrix polarimetry (MMP) is introduced to characterize nanoimprinted grating structures, and noticeable depolarization effects from measured data are observed. We demonstrate that these depolarization effects are mainly induced by the finite bandwidth and numerical aperture of the instrument, as well as the residual layer thickness variation of the measured sample. After incorporating the depolarization effects into the optical model, not only improved accuracy can be achieved for the line width, line height, and residual layer thickness measurement but also the residual layer thickness variation over the illumination spot can be directly determined by MMP.
Effect of V-defects on the performance deterioration of InGaN/GaN multiple-quantum-well light-emitting diodes with varying barrier layer thickness
Authors: Le L. C. , Zhao D. G. , Jiang D. S. , Li L. , Wu L. L. , Chen P. , Liu Z. S. , Yang J. , Li X. J. , He X. G. , Zhu J. J. , Wang H. , Zhang S. M. , Yang H.
Published: October 2013

The effect of quantum barrier (QB) thickness on performances of InGaN/GaN multiple-quantum-well light-emitting diodes (MQW LEDs) with relatively large barrier layer thicknesses has been investigated. It is found that the density and averaged size of V-defects increases with QB thickness, resulting in larger reverse- and forward-bias current in LEDs. Electroluminescence measurement shows that LED with thinner QB has higher internal quantum efficiency but lower efficiency droop-onset current density, which should be ascribed to the faster saturation of carrier leakage into V-defects. Correspondingly, above the droop-onset current density, severer Auger recombination and carrier overflow are induced by higher carrier density due to the less V-defect related carrier leakage, leading to the more serious droop phenomenon in LEDs with thinner QB.
Coulomb impurity effect on Dirac electron in graphene magnetic dot
Authors: Lee C. M. , Chan K. S.
Published: October 2013

Using the Dirac-Weyl model, we study the low-lying spectra of a massless Dirac electron bound to a positively charged Coulomb impurity in a graphene magnetic dot, for which the inhomogeneous magnetic field is created by different magnetic fields inside and outside the dot with a field ratio α. Numerical results show that the zero energy states, in the presence of the impurity, are converted into hole-like states. Additionally, for positive and negative α values, the states are, in general, located inside and outside the dot, respectively, causing the spectra to exhibit different features.
Effects of interface oxidation on the transport behavior of the two-dimensional-electron-gas in AlGaN/GaN heterostructures by plasma-enhanced-atomic-layer-deposited AlN passivation
Authors: Huang Sen , Wei Ke , Tang Zhikai , Yang Shu , Liu Cheng , Guo Lei , Shen Bo , Zhang Jinhan , Kong Xin , Liu Guoguo , Zheng Yingkui , Liu Xinyu , Chen Kevin J.
Published: October 2013

The effects of interface oxidation on the transport behavior of the 2-D electron gas (2DEG) in AlGaN/GaN heterostructures by plasma-enhanced-atomic-layer-deposited AlN (PEALD-AlN) passivation were investigated using temperature-dependent Hall-effect and X-ray photoelectron spectroscopy (XPS) characterizations. AlGaN/GaN heterostructure with a 4-nm-thick PEALD-AlN passivation exhibits good 2DEG transport behavior and stability at moderately high temperature (e.g., 275 °C). However, serious oxidation of the AlN/GaN (cap layer) interface occurs as the sample is heated up to 400 °C in low-pressure atmosphere, as verified by an increased Ga-O bond in Ga 3d core-level spectra. The oxidation leads to a significant reduction of 2.47 × 1012 cm−2 in the 2DEG density in the channel. A modified AlN passivation structure with Al2O3/AlN (10/4 nm) stack is shown to be able to effectively suppress the oxidation of the AlN/GaN interface, demonstrating an enhanced 2DEG density and high-temperature stability even when the sample is heated up to 500 °C. Based on XPS and 2DEG recovery experiments, it is suggested that acceptor-like deep levels have been generated in the near-surface region of AlGaN/GaN heterostructure because of the oxidation, and trapping of these deep levels results in significant depletion of the 2DEG in the channel. The effects of PEALD-AlN passivation on the strain in the AlGaN barrier of AlGaN/GaN heterostructures are also evaluated with high-resolution X-ray diffraction technique.
Si quantum dots with a high absorption coefficient: Analysis based on both intensive and extensive variables
Authors: Kitasako Takumi , Saitow Ken-ichi
Published: October 2013

Silicon quantum dots (Si-QDs) were produced by pulsed laser ablation in liquid. By measuring the absorption spectra and the concentration of the Si-QD solution, two extinction coefficients were obtained from UV to near IR region: the atomic molar extinction coefficient and the quantum dot molar extinction coefficient. The magnitude of the atomic molar extinction coefficient of the Si-QDs was found to be up to 30 and 270 times those of crystalline and amorphous Si, respectively, and up to 740 times that of previously fabricated Si-QDs. The Si-QDs remained stably dispersed in hydrocarbon and alcohol solvents for over 10 months.
Suppression of thermal degradation of InGaN/GaN quantum wells in green laser diode structures during the epitaxial growth
Authors: Li Zengcheng , Liu Jianping , Feng Meixin , Zhou Kun , Zhang Shuming , Wang Hui , Li Deyao , Zhang Liqun , Zhao Degang , Jiang Desheng , Wang Huaibing , Yang Hui
Published: October 2013

Local InGaN quantum well (QW) decomposition and resultant inhomogeneous luminescence in green laser diode (LD) epitaxial structures are investigated using micro-photoluminescence, Z-contrast scanning transmission electron microscopy, and high-resolution transmission electron microscopy. The local InGaN QW decomposition is found to happen during p-type layer growth due to too high thermal budget and may initiate at the InGaN/GaN QW upper interface probably due to the formation of In-rich InGaN clusters there. Reducing thermal budget and optimizing InGaN/GaN QW growth suppress the local InGaN QW decomposition, and green LD structures with homogeneous luminescence and bright electroluminescence (EL) intensity are obtained.
Tall-barrier terahertz quantum cascade lasers
Authors: Chan Chun Wang I. , Hu Qing , Reno John L.
Published: October 2013

A terahertz quantum cascade laser is presented in which selectively placed pure AlAs barriers are used to reduce parasitic leakage currents to the conduction band continuum. The design is demonstrated to have improved temperature performance over a regrowth of the current Tmax ∼ 200 K record holder (181 K vs. 175 K). Strangely, it fails to lase below ∼70 K, which we attribute to negative differential resistance (NDR) prior to threshold. A subsequent design using only AlAs barriers failed to lase, the reason for which we posit to be either early NDR or excessive interface roughness scattering.
Dielectric relaxations and magnetodielectric response in BiMn2O5 single crystal
Authors: Yin L. H. , Yuan B. , Chen J. , Zhang D. M. , Zhang Q. L. , Yang J. , Dai J. M. , Song W. H. , Sun Y. P.
Published: October 2013

Magnetic and dielectric properties have been investigated on BiMn2O5 single crystals. Magnetic measurements show that BiMn2O5 becomes antiferromagnetic below TN∼39 K, with short range magnetic correlation existing between TN and T∗∼100 K. Three thermally excited dielectric relaxations at temperatures TN<T<300 K and large intrinsic magnetodielectric effect due to the special arrangement of Mn3+/Mn4+ ions associated with electron hopping between them were observed. The low temperature anisotropic relaxation (TN<T<T∗) along the b-axis, which is insignificant along the c-axis, can be ascribed to electron hopping between the zigzag chains with short range magnetic correlation. The other two dielectric relaxations are also discussed.
Directionally controlled transfer printing using micropatterned stamps
Authors: Chen Hang , Feng Xue , Chen Ying
Published: October 2013

Kinetically controlled transfer printing based on rate-dependent adhesion is widely used to heterogeneously integrate micro/nano-devices. Through analysis of peeling stamps with grating-like micropatterns from the rigid substrate in different directions, the directionally dependent adhesion strength is investigated in detail. Experiments of peel test and picking up silicon ribbons from silicon-on-insulator wafer were conducted and consistent with the analytical prediction. The method and analytical results proposed in this Letter can guide the design of the micropatterns on stamp to realize a more effective transfer printing approach.
Note: Radial-thrust combo metal mesh foil bearing for microturbomachinery
Authors: Park Cheol Hoon , Choi Sang Kyu , Hong Doo Euy , Yoon Tae Gwang , Lee Sung Hwi
Published: October 2013

This Note proposes a novel radial-thrust combo metal mesh foil bearing (MMFB). Although MMFBs have advantages such as higher stiffness and damping over conventional air foil bearings, studies related to MMFBs have been limited to radial MMFBs. The novel combo MMFB is composed of a radial top foil, thrust top foils, and a ring-shaped metal mesh damper—fabricated by compressing a copper wire mesh—with metal mesh thrust pads for the thrust bearing at both side faces. In this study, the combo MMFB was fabricated in half-split type to support the rotor for a micro gas turbine generator. The manufacture and assembly process for the half-split-type combo MMFB is presented. In addition, to verify the proposed combo MMFB, motoring test results up to 250 000 rpm and axial displacements as a function of rotational speed are presented.
Thermoelectric properties of magnesium silicide fabricated using vacuum plasma thermal spray
Authors: Fu Gaosheng , Zuo Lei , Longtin Jon , Nie Chao , Gambino Richard
Published: October 2013

The thermoelectric properties of magnesium silicide samples prepared by Vacuum Plasma Spray (VPS) are compared with those made from the conventional hot press method using the same feedstock powder. Thermal conductivity, electrical conductivity, Seebeck coefficient, and figure of merit are characterized from room temperature to 700 K. X-ray diffraction and scanning electron microscopy of the samples are obtained to assess how phase and microstructure influence the thermoelectric properties. Carrier concentration and Hall mobility are obtained from Hall Effect measurements, which provide further insight into the electrical conductivity and Seebeck coefficient mechanisms. Low-temperature electrical conductivity measurements suggest a 3D variable range hopping effect in the samples. VPS samples achieved a maximum ZT = 0.16 at 700 K, which is around 30% of the hot press sample ZT = 0.55 at 700 K using the same raw powder. The results suggest that thermal spray is a potential deposition technique for thermoelectric materials.
Interstitial oxygen induced Fermi level pinning in the Al2O3-based high-k MISFET with heavy-doped n-type poly-Si gates
Authors: Yang Moon Young , Kamiya Katsumasa , Shiraishi Kenji
Published: October 2013

We study the origin of substantial threshold voltage (Vth) shifts observed in Al2O3-based MISFETs with n+poly-Si gate, by focusing on the effect of an interstitial oxygen (Oi) formation in Al2O3. We observed that the Oi level in Al2O3 is 1 eV above the valence band top of Al2O3 by first-principles calculation. Therefore, Oi formation and subsequent electron transfer from Fermi level to the Oi level allows the system to overcome the energy loss by the Oi formation, which depends on the position of Fermi level. In case of n+poly-Si gate, this electron transfer across the interface occurs and results in substantial Vth shifts. The proposed mechanism reproduces experimental result and provides a good understanding of nano-interfacial interactions.
Brass plasmoid in external magnetic field at different air pressures
Authors: Patel D. N. , Pandey Pramod K. , Thareja Raj K.
Published: October 2013

The behavior of expanding brass plasmoid generated by 266 nm wavelength of Nd:YAG laser in nonuniform magnetic field at different air pressures has been examined using optical emission spectroscopy and fast imaging of plasma plumes. The splitting of the plasma plumes and enhancement of intensity of Cu I at 510.5 nm in the presence of magnetic field at lower pressures are discussed. The threading and expulsion of the magnetic field lines through the plasmoid are correlated with the ambient pressure. The stoichiometry of the plasma plume is not significantly influenced by the magnetic field; however, the abundance of neutral to ionic species of Cu and Zn is greatly influenced by the magnetic field.
Gender agreement in L3 English by Basque/Spanish bilinguals
Authors: Agirre Ainara Imaz , García Mayo María del Pilar
Published: October 2013

This study investigates knowledge of the nominal agreement domain in L3 English by Basque/Spanish bilinguals. Gender agreement has been claimed to be an interpretable feature in English and could be claimed to be so for Basque, whereas Spanish shows uninterpretable gender agreement. Under current representational and computational accounts posited to explain variability in L2 learner production, interpretable features are acquirable. The participants in the present study (n=34) were Basque/Spanish bilinguals of two proficiency levels in English (intermediate and advanced) and a control group of English native speakers (n=17). They completed two oral production tasks (elicitation and picture narration tasks). Results from both tasks indicate that Basque/Spanish bilinguals seem to have acquired gender agreement in L3 English but still have production problems which could be explained on the basis of linguistic features (animacy) and gender attraction effects of the Spanish head noun as well as the different proficiency levels.
What’s so incomplete about incomplete acquisition?
Authors: Putnam Michael T. , Sánchez Liliana
Published: October 2013

Modeling the competence grammar of heritage speakers who exhibit low proficiency in their L1 represents a significant challenge for generative and experimental approaches to bilingual linguistic research. In this paper we revisit the core tenets of the incomplete acquisition hypothesis as developed in recent scholarship (in particular byMontrul (2002et seq.) andPolinsky (1997,2006)). Although we adopt many of these fundamental aspects of this research program, in this article we develop an alternative model that provides a more accurate depiction of the process that leads to what these scholars describe as the (later) effects of incomplete acquisition, thus improving the predictive power of this research program.
Breast‐Feeding and Weaning Practices in the DONALD Study
Authors: Foterek Kristina , Hilbig Annett , Alexy Ute
Published: October 2013

Objectives:

Besides influencing short‐ and long‐term health status, infant feeding practices are known to have an effect on later food preferences. This study aimed to identify present trends in breast‐feeding duration and weaning practices with special focus on preparation methods of complementary food (CF), that is, homemade and commercial CF.

Methods:

In total, 1419 three‐day weighed diet records collected between 2004 and 2012 from 366 children of the German DOrtmund Nutritional and Anthropometric Longitudinally Designed study ages 6 to 24 months were analysed. Full (n = 339) and total breast‐feeding duration (n = 344) was collected by questionnaire. To investigate age and time trends, logistic regression and polynomial mixed regression models were used.

Results:

Infants born between 2008 and 2012 were 3.3‐fold less likely to be fully breast‐fed for ≥4 months than those born before 2004 (P < 0.0001). Overall, 59.3% commercial, 21.1% homemade, and 19.6% combined CF was consumed by the study sample. Subjects with high commercial CF consumption (percentage of commercial CF > median 62%) were significantly older (P < 0.0001), showed shorter full and total breast‐feeding duration (P < 0.0001), and were more likely to have mothers with a lower educational status (P = 0.01). Both commercial and homemade CF showed opposing, nonlinear age trends. No time trends could be found.

Conclusions:

Decreasing duration of full breast‐feeding should encourage health care providers to further promote longer breast‐feeding duration. With the constantly high consumption of commercial CF at all ages, nutritional adequacy of both homemade and commercial CF needs to be investigated closer, as does their long‐term influence on health and dietary habits, for example, fruit and vegetable intake.
Disease Activity Is an Important Factor for Indeterminate Interferon‐γ Release Assay Results in Children With Inflammatory Bowel Disease
Authors: Hradsky Ondrej , Ohem Jan , Zarubova Kristyna , Mitrova Katarina , Durilova Marianna , Kotalova Radana , Nevoral Jiri , Zemanova Ilona , Dryak Pavel , Bronsky Jiri
Published: October 2013

Background:

Interferon‐γ release assay (IGRA) is widely used for screening of latent tuberculosis (TB) before and during biological therapy (BT). An indeterminate result of IGRA represents a limitation in the management of inflammatory bowel disease (IBD). Data on factors influencing IGRA results are scarce in children. The aim of the study was to identify factors influencing IGRA results in children with IBD.

Methods:

Seventy‐two children with IBD (59 Crohn disease, 11 ulcerative colitis, 2 IBD‐unclassified) indicated for BT were tested for TB infection (history, TB skin test, chest radiograph, IGRA; QuantiFERON—TB Gold in tube [QFT]) and consecutively retested using QFT in 1‐year intervals.

Results:

We recorded 165 results of QFT (3% positive, 87% negative, and 10% indeterminate results). During follow‐up we identified 4 conversions of negative QFT to positivity (3%) and 4 reversions (4%). Patients with indeterminate results of QFT had significantly lower actual weight‐for‐height z score (P = 0.022), higher platelet count (P = 0.00017), and lower levels of serum albumin (P = 0.015) compared with patients with positive or negative QFT. Indeterminate QFT was associated with corticosteroid treatment, BT, and disease activity, but not with treatment by immunomodulators. In a subanalysis of patients with Crohn disease alone, Pediatric Crohn's Disease Activity Index was identified as single independent risk factor for indeterminate results (P = 0.00037).

Conclusions:

Although corticosteroid treatment is traditionally considered to be the main risk factor for indeterminate results of IGRA, the disease activity of IBD has even more profound effects on the results.
Desulfatiferula berrensis sp. nov., a n-alkene-degrading sulfate-reducing bacterium isolated from estuarine sediments
Authors: Hakil Florence , Amin-Ali Oulfat , Hirschler-Réa Agnès , Mollex Damien , Grossi Vincent , Duran Robert , Matheron Robert , Cravo-Laureau Cristiana
Published: October 2013

A novel sulfate-reducing bacterium designated strain BE2801T was isolated from oil-polluted estuarine sediments (Berre Lagoon, France). Cells were Gram-stain-negative, motile, slightly curved or vibrioid rods. Optimal growth of strain BE2801T occurred at 30–32 °C, 0.5–1.5% NaCl (w/v) and pH 7.2–7.4. Strain BE2801T grew with C4 to C20 fatty acids or C12 to C20
n-alkenes as electron donors. Acetate and carbon dioxide were the oxidation products. The major cellular fatty acids were C16 : 0, C16 : 1ω7c and C18 : 1ω7. The DNA G+C content was 50.2 mol%. 16S rRNA and dsrAB gene sequence analysis indicated that strain BE2801T was a member of the family

Desulfobacteraceae

within the class

Deltaproteobacteria

. DNA–DNA hybridization with the most closely related taxon demonstrated 14.8 % relatedness. Based on phenotypic and phylogenetic evidence, strain BE2801T ( = DSM 25524T = JCM 18157T) is proposed to be a representative of a novel species of the genus

Desulfatiferula

, for which the name Desulfatiferula
berrensis sp. nov. is suggested.
Replication Protein A2c Coupled with Replication Protein A1c Regulates Crossover Formation during Meiosis in Rice
Authors: Li Xingwang , Chang Yuxiao , Xin Xiaodong , Zhu Chunmei , Li Xianghua , Higgins James D. , Wu Changyin
Published: October 2013

Replication protein A (RPA) is a conserved heterotrimeric protein complex comprising RPA1, RPA2, and RPA3 subunits involved in multiple DNA metabolism pathways attributable to its single-stranded DNA binding property. Unlike other species possessing a single RPA2 gene, rice (Oryza sativa) possesses three RPA2 paralogs, but their functions remain unclear. In this study, we identified RPA2c, a rice gene preferentially expressed during meiosis. A T-DNA insertional mutant (rpa2c) exhibited reduced bivalent formation, leading to chromosome nondisjunction. In rpa2c, chiasma frequency is reduced by ∼78% compared with the wild type and is accompanied by loss of the obligate chiasma. The residual ∼22% chiasmata fit a Poisson distribution, suggesting loss of crossover control. RPA2c colocalized with the meiotic cohesion subunit REC8 and the axis-associated protein PAIR2. Localization of REC8 was necessary for loading of RPA2c to the chromosomes. In addition, RPA2c partially colocalized with MER3 during late leptotene, thus indicating that RPA2c is required for class I crossover formation at a late stage of homologous recombination. Furthermore, we identified RPA1c, an RPA1 subunit with nearly overlapping distribution to RPA2c, required for ∼79% of chiasmata formation. Our results demonstrate that an RPA complex comprising RPA2c and RPA1c is required to promote meiotic crossovers in rice.
Improved protective efficacy of a chimeric Staphylococcus aureus vaccine candidate iron‐regulated surface determinant B (N126–P361)‐target of RNAIII activating protein in mice
Authors: Yu Liquan , Wang Ning , Ma Jinzhu , Tong Chunyu , Song Baifen , Chi Jiaqi , Ma Guoda , Zhu Zhanbo , Cui Yudong
Published: October 2013

The pathogen Staphylococcus aureus causes a wide range of serious infections, necessitating urgent development of a vaccine against this organism. However, currently developed vaccines are relatively ineffective because of the limited antigenic component that is contained in the vaccine formulations. To develop an effective S. aureus candidate vaccine, overlapping PCR was used to add the truncated immunodominant antigen iron‐regulated surface determinant B (IsdB)(N126–P361) (tIsdB) to the N‐terminal of intact antigen target of RNAIII activating protein (TRAP) and thus construct a tIsdB‐TRAP chimera. The humoral and cellular immune responses against tIsdB‐TRAP were compared with those against single or combined formulations. tIsdB‐TRAP elicited significantly stronger humoral responses in mice (P < 0.05). As to cellular immune responses in mice, the tIsdB‐TRAP group resulted in a greater IL‐4 response than did other groups (P < 0.05). Greater amounts of IL‐2 and IFN‐γ were found in the tIsdB‐TRAP group. Mouse challenge also showed that tIsdB‐TRAP provided better protection against S. aureus than did the control groups. These results suggest that this chimeric protein may be a promising pathogen target for further vaccine development.
Grazing alters insect visitation networks and plant mating systems
Authors: Vanbergen Adam J. , Woodcock Ben A. , Gray Alan , Grant Fiona , Telford Annika , Lambdon Phil , Chapman Dan S. , Pywell Richard F. , Heard Matt S. , Cavers Stephen
Published: October 2013

Many flowering plant species have a facultative or obligate dependence on insect pollination for reproductive success. Anthropogenic disturbance may alter these species interactions, but the extent to which structural changes to plant‐pollinator networks affect plant species mating systems is not well understood.

We used long‐term livestock grazing of a birch wood ecosystem to test whether disturbance of this semi‐natural habitat altered floral resources, the structure of plant–insect visitation networks and the mating system of a focal plant species, Cirsium palustre.

Grazed habitat had a higher species richness of floral resources for pollinators. Visitation networks in grazed habitats were larger, more diverse, with an increase in the number of pollinators per plant species. Controlling for sampling effects, however, showed networks in grazed habitats were less nested and revealed a positive correlation between network connectance and floral species richness.

Network connectance was negatively related to C. palustre outcrossing rate within grazed and ungrazed sites. However, on average, the effects of grazing, including greater mean connectance, produced higher overall outcrossing rates and more pollen donors compared with ungrazed habitat. The number of different pollen donors, spatial genetic structure and mating among close relatives were all correlated with greater extent of suitable C. palustre habitat in the landscape, consistent with the effects of increasing plant population size but limited seed dispersal.

Pre‐adaptation of C. palustre to disturbance coupled with a preponderance of highly dispersive flies attracted to the greater food resources in grazed habitat is a likely mechanism underpinning this increased pollen transport.

Habitat modification by long‐term mammalian grazing fundamentally shifted visitation network structure and the state of a plant mating system, indicating how ecosystem disturbance can cascade across levels of biological organization through altered interspecific interactions. Cirsium palustre retains flexibility to bias reproduction towards selfing where pollen donor diversity is limited; such reproductive flexibility may be an important mechanism structuring plant populations in human‐modified landscapes.
Adaptive maternal and paternal effects: gamete plasticity in response to parental stress
Authors: Jensen Natasha , Allen Richard M. , Marshall Dustin J.
Published: October 2013

Transgenerational phenotypic plasticity is increasingly recognized as an important buffer of environmental change – many studies show that mothers alter the phenotype of their offspring so as to maximize their performance in their local environment. Fewer studies have examined the capacity of parents to alter the phenotype of their gametes to cope with environmental change. In organisms that shed their gametes externally, gametes are extremely vulnerable to local stresses and transgenerational plasticity in the phenotypes of gametes seems likely in this group.

In a marine tubeworm, Hydroides diramphus, we manipulated the salinity environment that mothers and fathers experienced before reproduction and then examined the phenotype of their gametes, as well as the performance of those gametes and the resultant larvae in different salinities.

We found strong evidence for gamete plasticity – both mothers and fathers adaptively adjust the phenotype of their gametes to maximize the performance of those gametes in the salinity regime experienced by their parents. Parents were quite flexible in the phenotype of gametes that they produced: they could switch the salinity tolerance of their gametes back and forth depending on their most recent experience.

Gamete plasticity was not without risks, however. We observed strong trade‐offs in performance when gametes experienced an environment that did not match that of their parents. These effects of the parental environment persist for the duration of the larval phase such that larvae may not be able to disperse to environments that do not match their parents. Gamete plasticity may therefore represent an important source of phenotype–environment mismatches.

Gamete plasticity may represent an important mechanism for coping with environmental change and an important source of maternal and paternal effects in species with external fertilization. Studies that seek to predict the impacts of stresses that persist across generations (e.g. ocean acidification) should include parental exposures to the stress of interest.
Elevated maternal temperature enhances offspring disease resistance in Daphnia magna
Authors: Garbutt Jennie S. , Scholefield Jennifer A. , Vale Pedro F. , Little Tom J.
Published: October 2013

Maternal effects are increasingly recognized to impact upon infectious diseases. Stressful environmental conditions that coincide with high infection prevalence are potential cues for adaptive maternal effects on offspring resistance to infection.

We studied how maternal temperature (15 °C, 20 °C and 25 °C), as well as maternal food availability (high and low food) influenced the ability of the crustacean, Daphnia magna, to resist its bacterial parasite, Pasteuria ramosa.

Mothers held at a higher temperature and mothers fed a restricted diet produced offspring that were more resistant to P. ramosa infection.

Maternal temperature also influenced the progression of disease in infected offspring. Parasite spore production and host reproduction were affected by maternal temperature, but these effects differed in the two genotypes used.

As Daphnia populations experience regular summer epidemics of P. ramosa, temperature may be an environmental signal of infection risk. Thus, the enhanced resistance we observed under stressful food and temperature is conceivably an adaptation to looming epidemics.

Thus, this study identifies novel ways in which the maternal environment impacts upon disease resistance and indicates how phenotypic plasticity might both alter co‐evolution and mitigate epidemics driven by environmental change in a wide range of taxa.