bluuebunny/crossref_metadata_2025 huggingface dataset:
The influence of landform on the understory plant community in a temperate Beech forest in northern Iran
Authors: Fazlollahi Mohammadi Maryam , Jalali Seyed Gholamali , Kooch Yahya , Theodose Theresa A.
Published: December 2014

Understanding the factors that determine the distribution of understory plants is important because they represent the largest component of temperate forest plant diversity. We examined the influence of topographic gradients on the distribution of understory plants in Mazandaran Province, northern Iran. Our objective was to determine how the topography of the landscape influenced the composition of understory plant species (cover, diversity, richness, and evenness). We investigated two catena landscape shapes (Λ and V), several different slope positions and their subsequent effects on the composition of the understory herb layer. We established 120 plots that spanned six catenas that varied in shape and slope position (i.e, summit, shoulder, back slope, foot slope and toe slope). We measured the composition of understory plant species populations and calculated diversity using several indices. We found that plant distribution and abundance was strongly related to both catena shape and slope position. Statistical analyses revealed that plant species diversity and richness varied significantly with slope position of the catena, but only diversity varied with catena shape. In addition, significant interactions were found for both diversity and richness. Neither shape nor slope position had a significant effect on evenness alone. We concluded that catena shape and slope position both influence plant distribution, abundance, and biodiversity of the herb layer in these forests by affecting both understory light intensity and soil factors. Our results suggest that the herb layer on Λ‐shaped catenas and V‐shaped landforms were mostly controlled by topography and soil features, respectively.
Parental attitude toward deviance as a predictor of delinquency: Making the connection via perception and cognition
Authors: Walters Glenn D.
Published: December 2014

This study tested a core postulate of social cognitive theory: i.e., that perception precedes cognition in the development of behavior. Using data from four of the first five waves of the 1725‐member (918 males, 807 females) National Youth Survey (NYS), youth perception of parental attitude toward deviance and youth attitude toward deviance at Waves 2 and 3 were tested as possible mediators of the relationship between Wave 1 parental attitude toward deviance and self‐reported delinquency at Wave 5. The target chain was both significant and significantly stronger than the reverse chain and there was no evidence that age, race, or sex moderated this mediated relationship. These results support the presence of a chaining process in which proximal social, perceptual, and cognitive events link to distal behavioral outcomes like delinquency.
Argo and Zero Dark Thirty: Film, Government, and Audiences
Authors: Pautz Michelle C.
Published: December 2014

With the prevalence and accessibility of film today, we must wonder how film affects its audience. In particular, how does film influence an audience’s perceptions of the government? Regardless of the content, research demonstrates that film has the power to shape perceptions of its moviegoers on a range of subjects. In this study, two recent films,ArgoandZero Dark Thirty, were chosen as case studies to explore how Hollywood portrays the intelligence community in film and shapes opinions about the government more broadly. This research found that about 25% of viewers of the two films changed their opinion about the government after watching one of the movies. Additionally, many of those changes are reflected in an improvement in the sentiments about the government and its institutions. This exploratory research provokes interesting discussions about the ability of film to influence the perceptions of an audience.
Assembly of tetrameric dimethyltin-functionalized selenotungstates: from nanoclusters to one-dimensional chains
Authors: Chen Wei-Chao , Qin Chao , Li Yang-Guang , Zang Hong-Ying , Shao Kui-Zhan , Su Zhong-Min , Wang En-Bo , Liu Hong-Sheng
Published: December 2014

The first dimethyltin-functionalized selenotungstates have been isolated: nanocluster {Sn7Se8W54} exhibiting photocatalytic H2 evolution activity and chain {Sn16Se11W56} contain {β-Se2W15} and {γ-Se2W14} building blocks, respectively.
Synthesis of ultra-small BaLuF5:Yb3+,Er3+@BaLuF5:Yb3+ active-core–active-shell nanoparticles with enhanced up-conversion and down-conversion luminescence by a layer-by-layer strategy
Authors: Zhang Yongling , Liu Xiaohui , Lang Yanbo , Yuan Zhen , Zhao Dan , Qin Guanshi , Qin Weiping
Published: December 2014

Ultra-small luminescent nanoparticles (NPs) are quite desirable for optoelectronic and biomedical applications.
Charge injection promoted electrohydrodynamic instabilities in poly(3-hexylthiophene) thin films
Authors: Ye Zhi , Cui Huina , Yang Xiubao , Qiu Feng
Published: December 2014

Electrohydrodynamic instabilities in poly(3-hexylthiophene) thin films are able to induce uniformly distributed, micrometer scale columns each composed of a spherulite.
Ambipolar charge-transport properties in 4,10-dihalogenated anthanthrone crystals: a theoretical study
Authors: Tu Zeyi , Huang Xuri , Yi Yuanping
Published: December 2014

Good ambipolar charge-transport characteristics have been revealed for the halogenated anthanthrone crystals by DFT and MD calculations.
How “Proficient” Is Proficient? Bilingual Listeners' Recognition of English Words in Noise
Authors: Shi Lu-Feng
Published: December 2014

Purpose

Shi (2011, 2013) obtained sensitivity/specificity measures of bilingual listeners' English and relative proficiency ratings as the predictor of English word recognition in quiet. The current study investigated how relative proficiency predicted word recognition in noise.

Method

Forty-two monolingual and 168 bilingual normal-hearing listeners were included. Bilingual listeners rated their proficiency in listening, speaking, and reading in English and in the other language using an 11-point scale. Listeners were presented with 50 English monosyllabic words in quiet at 45 dB HL and in multitalker babble with a signal-to-noise ratio of +6 and 0 dB.

Results

Data in quiet confirmed Shi's (2013) finding that relative proficiency with or without dominance predicted well whether bilinguals performed on par with the monolingual norm. Predicting the outcome was difficult for the 2 noise conditions. To identify bilinguals whose performance fell below the normative range, dominance per se or a combination of dominance and average relative proficiency rating yielded the best sensitivity/specificity and summary measures, including Youden's index.

Conclusion

Bilinguals' word recognition is more difficult to predict in noise than in quiet; however, proficiency and dominance variables can predict reasonably well whether bilinguals may perform at a monolingual normative level.
Tinnitus and Hearing Survey: A Screening Tool to Differentiate Bothersome Tinnitus From Hearing Difficulties
Authors: Henry James A. , Griest Susan , Zaugg Tara L. , Thielman Emily , Kaelin Christine , Galvez Gino , Carlson Kathleen F.
Published: December 2014

Purpose

Individuals complaining of tinnitus often attribute hearing problems to the tinnitus. In such cases some (or all) of their reported “tinnitus distress” may in fact be caused by trouble communicating due to hearing problems. We developed the Tinnitus and Hearing Survey (THS) as a tool to rapidly differentiate hearing problems from tinnitus problems.

Method

For 2 of our research studies, we administered the THS twice (mean of 16.5 days between tests) to 67 participants who did not receive intervention. These data allow for measures of statistical validation of the THS.

Results

Reliability of the THS was good to excellent regarding internal consistency (α = .86–.94), test–retest reliability (
r
= .76–.83), and convergent validity between the Tinnitus Handicap Inventory (Newman, Jacobson, & Spitzer, 1996; Newman, Sandridge, & Jacobson, 1998) and the A (Tinnitus) subscale of the THS (
r
= .78). Factor analysis confirmed that the 2 subscales, A (Tinnitus) and B (Hearing), have strong internal structure, explaining 71.7% of the total variance, and low correlation with each other (
r
= .46), resulting in a small amount of shared variance (21%).

Conclusion

These results provide evidence that the THS is statistically validated and reliable for use in assisting patients and clinicians in quickly (and collaboratively) determining whether intervention for tinnitus is appropriate.
Electromagnetic band-gap structure design using the auxetic unit-structure for easily controllable tunability
Authors: Lim Heeseung , Shin Dongheok , Kim Kyoungsik , Yoo Jeonghoon
Published: December 2014

Tunable electromagnetic band-gap structures for matching an intended band-gap range have more potential for various applications than ordinary electromagnetic band-gap structures with a fixed or non-linearly variable band-gap range. However, there has not been much progress on the study of the appropriate shape of the structure. To obtain a controllable and tunable electromagnetic band-gap, we propose a new design concept employing a unit-structure with a negative Poisson's ratio close to −1 to realize an approximately linear band-gap shift according to the variation of the shape of the structure. We used a structural optimization procedure based on the phase field method to obtain the design of the unit-structure. We investigated the relation between the auxetic unit-structure deformation and the change in the band-gap range through numerical simulations and also evaluated the possibility to realize the design experimentally in the radio frequency range.
Mechanostability of cohesin-dockerin complexes in a structure-based model: Anisotropy and lack of universality in the force profiles
Authors: Wojciechowski Michał , Thompson Damien , Cieplak Marek
Published: December 2014

We use a structure-based coarse grained model to elucidate stretching of three cohesin-dockerin complexes that are found in the cellulosome. The average strength of mechanostability is comparable to that of the I27 domain of titin, but the force profiles depend on the pulling direction and anisotropy effects can be substantial. Even though the force profiles for individual cohesins and dockerins are similar, those for their complexes are visibly distinct for any pulling direction.
Electric field induced spin and valley polarization within a magnetically confined silicene channel
Authors: Liu Yiman , Zhou Xiaoying , Zhou Ma , Long Meng-Qiu , Zhou Guanghui
Published: December 2014

We study the electronic structure and transport properties of Dirac electrons along a channel created by an exchange field through the proximity of ferromagnets on a silicene sheet. The multiple total internal reflection induces localized states in the channel, which behaves like an electron waveguide. An effect of spin- and valley-filtering originating from the coupling between valley and spin degrees is predicted for such a structure. Interestingly, this feature can be tuned significantly by locally applying electric and exchange fields simultaneously. The parameter condition for observing fully spin- and valley-polarized current is obtained. These findings may be observable in todays' experimental technique and useful for spintronic and valleytronic applications based on silicene.
Modeling nonlinear viscoelasticity in dynamic acoustoelasticity
Authors: Trarieux Chloé , Callé Samuel , Moreschi Hélène , Renaud Guillaume , Defontaine Marielle
Published: December 2014

Dynamic Acoustoelastic Testing (DAET) has been developed to non-invasively assess the nonlinear viscoelastic properties of fluids and solids. We propose a phenomenologically motivated model for harmonic regime to identify nonlinear viscoelastic parameters from DAET experiments. The nonlinear elastic and viscous parameters are derived from the real and imaginary components of the Taylor series expansion of the complex longitudinal modulus. The model is applied to Newtonian fluids that exhibit classical elastic nonlinearities and glass beads saturated with water that exhibit nonclassical viscoelastic nonlinearities. Hysteresis, asymmetry, and DC offset are well accounted for in the model.
A complex guided spectral transform Lanczos method for studying quantum resonance states
Authors: Yu Hua-Gen
Published: December 2014

A complex guided spectral transform Lanczos (cGSTL) algorithm is proposed to compute both bound and resonance states including energies, widths, and wavefunctions. The algorithm comprises of two layers of complex-symmetric Lanczos iterations. A short inner layer iteration produces a set of complex formally orthogonal Lanczos polynomials. They are used to span the guided spectral transform function determined by a retarded Green operator. An outer layer iteration is then carried out with the transform function to compute the eigen-pairs of the system. The guided spectral transform function is designed to have the same wavefunctions as the eigenstates of the original Hamiltonian in the spectral range of interest. Therefore, the energies and/or widths of bound or resonance states can be easily computed with their wavefunctions or by using a root-searching method from the guided spectral transform surface. The new cGSTL algorithm is applied to bound and resonance states of HO2, and compared to previous calculations.
Low-order modeling of wind farm aerodynamics using leaky Rankine bodies
Authors: Araya Daniel B. , Craig Anna E. , Kinzel Matthias , Dabiri John O.
Published: December 2014

We develop and characterize a low-order model of the mean flow through an array of vertical-axis wind turbines (VAWTs), consisting of a uniform flow and pairs of potential sources and sinks to represent each VAWT. The source and sink in each pair are of unequal strength, thereby forming a “leaky Rankine body” (LRB). In contrast to a classical Rankine body, which forms closed streamlines around a bluff body in potential flow, the LRB streamlines have a qualitatively similar appearance to a separated bluff body wake; hence, the LRB concept is used presently to model the VAWT wake. The relative strengths of the source and sink are determined from first principles analysis of an actuator disk model of the VAWTs. The LRB model is compared with field measurements of various VAWT array configurations measured over a 3-yr campaign. It is found that the LRB model correctly predicts the ranking of array performances to within statistical certainty. Furthermore, by using the LRB model to predict the flow around two-turbine and three-turbine arrays, we show that there are two competing fluid dynamic mechanisms that contribute to the overall array performance: turbine blockage, which locally accelerates the flow; and turbine wake formation, which locally decelerates the flow as energy is extracted. A key advantage of the LRB model is that optimal turbine array configurations can be found with significantly less computational expense than higher fidelity numerical simulations of the flow and much more rapidly than in experiments.
Laterally inherently thin amorphous-crystalline silicon heterojunction photovoltaic cell
Authors: Chowdhury Zahidur R. , Kherani Nazir P.
Published: December 2014

This article reports on an amorphous-crystalline silicon heterojunction photovoltaic cell concept wherein the heterojunction regions are laterally narrow and distributed amidst a backdrop of well-passivated crystalline silicon surface. The localized amorphous-crystalline silicon heterojunctions consisting of the laterally thin emitter and back-surface field regions are precisely aligned under the metal grid-lines and bus-bars while the remaining crystalline silicon surface is passivated using the recently proposed facile grown native oxide–plasma enhanced chemical vapour deposited silicon nitride passivation scheme. The proposed cell concept mitigates parasitic optical absorption losses by relegating amorphous silicon to beneath the shadowed metallized regions and by using optically transparent passivation layer. A photovoltaic conversion efficiency of 13.6% is obtained for an untextured proof-of-concept cell illuminated under AM 1.5 global spectrum; the specific cell performance parameters are VOC of 666 mV, JSC of 29.5 mA-cm−2, and fill-factor of 69.3%. Reduced parasitic absorption, predominantly in the shorter wavelength range, is confirmed with external quantum efficiency measurement.
Rotation commensurate echo of asymmetric molecules—Molecular fingerprints in the time domain
Authors: Chesnokov E. N. , Kubarev V. V. , Koshlyakov P. V.
Published: December 2014

Using the pulses of terahertz free electron laser and ultra-fast Schottky diode detectors, we observed the coherent transients within a free induction decay of gaseous nitrogen dioxide NO2. The laser excited different sub-bands of rotation spectra of NO2 containing about 50–70 lines. The free induction signal continued more than 30 ns and consisted of many echo-like bursts duration about 0.2 ns. Unlike the similar effect observed previously for linear and symmetric top molecules, the sequence of echo bursts is not periodic. The values for delay of individual echo are stable, and the set of these delays can be considered as a “molecular fingerprint” in the time domain.
Observation of mid-infrared intersubband absorption in non-polar m-plane AlGaN/GaN multiple quantum wells
Authors: Kotani Teruhisa , Arita Munetaka , Arakawa Yasuhiko
Published: December 2014

Mid-infrared (4.20–4.84 μm) intersubband absorption in non-polar m-plane Al0.5Ga0.5N/GaN multiple-quantum wells is observed at room temperature. 10 period Al0.5Ga0.5N/GaN multiple-quantum wells were grown on free-standing m-plane GaN substrates by metalorganic chemical vapor deposition (MOCVD), and the high-quality structural and optical properties are revealed by x-ray diffraction and photoluminescence studies. Through this we have demonstrated that MOCVD grown non-polar m-plane AlGaN/GaN quantum wells are a promising material for mid-infrared intersubband devices.
Temperature dependence of the acoustoelectric current in graphene
Authors: Bandhu L. , Nash G. R.
Published: December 2014

The acoustoelectric current in graphene has been investigated as a function of temperature, surface acoustic wave (SAW) intensity, and frequency. At high SAW frequencies, the measured acoustoelectric current decreases with decreasing temperature, but remains positive, which corresponds to the transport of holes, over the whole temperature range studied. The current also exhibits a linear dependence on the SAW intensity, consistent with the interaction between the carriers and SAWs being described by a relatively simple classical relaxation model. At low temperatures and SAW frequencies, the measured acoustoelectric current no longer exhibits a simple linear dependence on the SAW intensity, and the direction of the acoustoelectric current is also observed to reverse under certain experimental conditions.
Nonlinear phase field model for electrodeposition in electrochemical systems
Authors: Liang Linyun , Chen Long-Qing
Published: December 2014

A nonlinear phase-field model has been developed for describing the electrodeposition process in electrochemical systems that are highly out of equilibrium. Main thermodynamic driving forces for the electrode-electrolyte interface (EEI) evolution are limited to local variations of overpotential and ion concentration. Application of the model to Li-ion batteries describes the electrode interface motion and morphology change caused by charge mass transfer in the electrolyte, an electrochemical reaction at the EEI and cation deposition on the electrode surface during the charging operation. The Li electrodeposition rate follows the classical Butler-Volmer kinetics with exponentially and linearly depending on local overpotential and cation concentration at the electrode surface, respectively. Simulation results show that the Li deposit forms a fiber-like shape and grows parallel to the electric field direction. The longer and thicker deposits are observed both for higher current density and larger rate constant where the surface reaction rate is expected to be high. The proposed diffuse interface model well captures the metal electrodeposition phenomena in plenty of non-equilibrium electrochemical systems.
Reversible order-disorder related band gap changes in Cu2ZnSn(S,Se)4 via post-annealing of solar cells measured by electroreflectance
Authors: Krämmer Christoph , Huber Christian , Zimmermann Christian , Lang Mario , Schnabel Thomas , Abzieher Tobias , Ahlswede Erik , Kalt Heinz , Hetterich Michael
Published: December 2014

We report on order–disorder related band gap changes in Cu2ZnSn(S,Se)4 solar cells which are induced by post-annealing. The band gap changes of the absorber are detected utilizing electroreflectance and analyzed by comparison with predictions of the stochastic Vineyard model. This yields a critical temperature of TC=195 °C above which the Cu2ZnSn(S,Se)4 absorber layer is entirely disordered within the Cu–Zn layers of the kesterite unit cell. The temporal evolution of the band gap during annealing shows that the equilibrium value is reached on a timescale in the order of hours, depending on the annealing temperature. In contrast to other experimental techniques, electroreflectance precisely measures the band gap and is not influenced by defect-mediated radiative recombination.
Mechanism of multiple grating formation in high-energy recording of holographic sensors
Authors: Yetisen Ali K. , Montelongo Yunuen , Farandos Nicholas M. , Naydenova Izabela , Lowe Christopher R. , Yun Seok Hyun
Published: December 2014

We report numerical analyses of Bragg diffraction by Denisyuk reflection holograms recorded by a high-energy pulsed laser. An intensity threshold must be passed to pattern a multilayer reflection and transmission hologram, which exhibits a nonlinear fringe structure. Numerical evaluations are provided for the laser light intensity, readout diffraction offset angle, transmission of the layer, and thickness of the polymer matrix during hologram recording. A non-sinusoidal surface pattern is formed at the top of the multilayer structure, and its effect on the diffraction properties of the structure becomes significant when the recording tilt angle is increased. Experimental results show that the angle of the diffracted light increases nonlinearly according to the tilt geometry in grating formation.
Hypericin-mediated selective photomodification of connective tissues
Authors: Hovhannisyan V. , Hovhannisyan A. , Ghukasyan V. , Guo H. W. , Chen Y. F. , Dong C. Y.
Published: December 2014

Controllable modification of biological molecules and supramolecular components of connective tissue are important for biophysical and biomedical applications. Through the use of second harmonic generation imaging, two-photon fluorescence microscopy, and spectrofluorimetry, we found that hypericin, a natural pigment, induces photosensitized destruction of collagen fibers but does not affect elastic fibers and lipids in chicken tendon, skin, and blood vessels. We demonstrated the dynamics and efficiency of collagen photomodification and investigated mechanisms of this processes. Our results suggest that hypericin–mediated photoprocesses in biological tissues may be useful in biomedical applications that require selective modification of connective tissues.
Low-temperature operation of junctionless nanowire transistors: Less surface roughness scattering effects and dominant scattering mechanisms
Authors: Jeon Dae-Young , Park So Jeong , Mouis Mireille , Barraud Sylvain , Kim Gyu-Tae , Ghibaudo Gérard
Published: December 2014

The less surface roughness scattering effects, owing to the unique operation principle, in junctionless nanowire transistors (JLT-NW) were shown by low-temperature characterization and 2D numerical simulation results. This feature could allow a better current drive under a high gate bias. In addition, the dominant scattering mechanisms in JLT-NW, with both a short (LM = 30 nm) and a long channel (LM = 10 μm), were investigated through an in-depth study of the temperature dependence of transconductance (gm) behavior and compared to conventional inversion-mode nanowire transistors.
Measurement of the hot electron mean free path and the momentum relaxation rate in GaN
Authors: Suntrup Donald J. , Gupta Geetak , Li Haoran , Keller Stacia , Mishra Umesh K.
Published: December 2014

We present a method for measuring the mean free path and extracting the momentum relaxation time of hot electrons in GaN using the hot electron transistor (HET). In this device, electrons are injected over a high energy emitter barrier into the base where they experience quasi-ballistic transport well above the conduction band edge. After traversing the base, high energy electrons either surmount the base-collector barrier and become collector current or reflect off the barrier and become base current. We fabricate HETs with various base thicknesses and measure the common emitter transfer ratio (α) for each device. The mean free path is extracted by fitting α to a decaying exponential as a function of base width and the relaxation time is computed using a suitable injection velocity. For devices with an injection energy of ∼1 eV, we measure a hot electron mean free path of 14 nm and calculate a momentum relaxation time of 16 fs. These values are in agreement with theoretical calculations where longitudinal optical phonon scattering is the dominant momentum relaxation mechanism.
Gating of high-mobility InAs metamorphic heterostructures
Authors: Shabani J. , McFadden A. P. , Shojaei B. , Palmstrøm C. J.
Published: December 2014

We investigate the performance of gate-defined devices fabricated on high mobility InAs metamorphic heterostructures. We find that heterostructures capped with In0.75Ga0.25As often show signs of parallel conduction due to proximity of their surface Fermi level to the conduction band minimum. Here, we introduce a technique that can be used to estimate the density of this surface charge that involves cool-downs from room temperature under gate bias. We have been able to remove the parallel conduction under high positive bias, but achieving full depletion has proven difficult. We find that by using In0.75Al0.25As as the barrier without an In0.75Ga0.25As capping, a drastic reduction in parallel conduction can be achieved. Our studies show that this does not change the transport properties of the quantum well significantly. We achieved full depletion in InAlAs capped heterostructures with non-hysteretic gating response suitable for fabrication of gate-defined mesoscopic devices.
Beam paths of flexural Lamb waves at high frequency in the first band within phononic crystal-based acoustic lenses
Authors: Zhao J. , Bonello B. , Boyko O.
Published: December 2014

This work deals with an analytical and numerical study of the focusing of the lowest order anti-symmetric Lamb wave in gradient index phononic crystals. Computing the ray trajectories of the elastic beam allowed us to analyze the lateral dimensions and shape of the focus, either in the inner or behind the phononic crystal-based acoustic lenses, for frequencies within a broad range in the first band. We analyzed and discussed the focusing behaviors inside the acoustic lenses where the focalization at sub-wavelength scale was achieved. The focalization behind the gradient index phononic crystal is shown to be efficient as well: we report on FMHM = 0.63λ at 11MHz.
Integration of atomic layer deposited high-k dielectrics on GaSb via hydrogen plasma exposure
Authors: Ruppalt Laura B. , Cleveland Erin R. , Champlain James G. , Bennett Brian R. , Prokes Sharka M.
Published: December 2014

In this letter we report the efficacy of a hydrogen plasma pretreatment for integrating atomic layer deposited (ALD) high-k dielectric stacks with device-quality p-type GaSb(001) epitaxial layers. Molecular beam eptiaxy-grown GaSb surfaces were subjected to a 30 minute H2/Ar plasma treatment and subsequently removed to air. High-k HfO2 and Al2O3/HfO2 bilayer insulating films were then deposited via ALD and samples were processed into standard metal-oxide-semiconductor (MOS) capacitors. The quality of the semiconductor/dielectric interface was probed by current-voltage and variable-frequency admittance measurements. Measurement results indicate that the H2-plamsa pretreatment leads to a low density of interface states nearly independent of the deposited dielectric material, suggesting that pre-deposition H2-plasma exposure, coupled with ALD of high-k dielectrics, may provide an effective means for achieving high-quality GaSb MOS structures for advanced Sb-based digital and analog electronics.
Optical temperature sensing by upconversion luminescence of Er doped Bi5TiNbWO15ferroelectric materials
Authors: Zou Hua , Wang Xusheng , Hu Yifeng , Zhu Xiaoqin , Sui Yongxing , Song Zhitang
Published: December 2014

The Er3+ doped Bi5TiNbWO15 ceramics have been synthesized using conventional solid-state reaction techniques. The crystal structure, ferroelectric properties, UC emission properties and especially the temperature sensing behaviors were systematically studied. With increasing Er3+ content, the investigation of XRD pattern, the ferroelectric loop and the UC emission indicated that the Er3+ ions dopants preferentially substituted the A sites of Bi3TiNbO9 and then Bi2WO6. Based on fluorescence intensity ratio (FIR) technique, the observed results implied the ceramics were promising candidates for temperature sensors in the temperature range of 175 K −550 K. More importantly, this study provided a contrast of temperature sensitivity between emission from the same part (Bi3TiNbO9) in bismuth layered-structure and emission from the different part (Bi3TiNbO9 and Bi2WO6) in bismuth layered-structure for the first time.
Online metrics show who’s saying what about scientists’ research
Authors: Matthews Jermey N. A.
Published: December 2014

Journal websites are now highlighting their articles’ likes, shares, and tweets, but information scientists still aren’t sure what the numbers really mean.
China carves out larger role in underground science
Authors: Feder Toni
Published: December 2014

As it is doing in so many areas of science, China is racing onto the world stage of underground astroparticle physics.
DOE takes another step toward exascale computing
Authors: Kramer David
Published: December 2014

New supercomputers will allow more detailed simulations for nuclear weapons research and a range of scientific applications.
INK4
locus of the tumor-resistant rodent, the naked mole rat, expresses a functional p15/p16 hybrid isoform
Authors: Tian Xiao , Azpurua Jorge , Ke Zhonghe , Augereau Adeline , Zhang Zhengdong D. , Vijg Jan , Gladyshev Vadim N. , Gorbunova Vera , Seluanov Andrei
Published: December 2014

Significance

The naked mole rat is a longest lived and cancer-resistant rodent. Tumor resistance in the naked mole rat is mediated by signals from the extracellular matrix component hyaluronan triggering the induction of
INK4
(inhibitors of cyclin dependent kinase 4) locus expression. The human and mouse
INK4
locus encodes three critical tumor-suppressor proteins, p15
INK4b
, ARF (alternate reading frame), and p16
INK4a
, which are among the most frequently mutated in cancer. Furthermore, p16
INK4a
is implicated in aging and senescence. Here, we show that the naked mole rat
INK4
locus encodes an additional product, a hybrid between p15
INK4b
and p16
INK4a
. The novel product, named pALT
INK4a/b
, may contribute to tumor resistance and longevity of the naked mole rat. Understanding the regulation of the
INK4
locus is critical for cancer and aging research.
The chemistry of negotiation: Rhythmic, glycan-driven acidification in a symbiotic conversation
Authors: Schwartzman Julia A. , Koch Eric , Heath-Heckman Elizabeth A. C. , Zhou Lawrence , Kremer Natacha , McFall-Ngai Margaret J. , Ruby Edward G.
Published: December 2014

Significance

The chemical dialog through which a host promotes long-term symbioses with particular microbial partners remains largely unexplored, especially within complex consortia like the human microbiota. Natural, monospecific associations, including that between bobtail squid andVibrio fischeri, have proved useful for discovering shared strategies, such as rhythmic microbial signaling and symbiosis-induced development, subsequently found in mammalian associations. Here, we demonstrate that symbiont metabolism is driven by a diel provision of a squid-derived glycan, resulting in tissue acidification. This event alters bacterial physiology, favoring the cyclic production of bioluminescence, the functional basis of the symbiosis. More generally, studies of this association can help reveal mechanisms by which other hosts modulate the chemistry of symbiosis to regulate microbial community function.
Tracking heavy water (D
2
O) incorporation for identifying and sorting active microbial cells
Authors: Berry David , Mader Esther , Lee Tae Kwon , Woebken Dagmar , Wang Yun , Zhu Di , Palatinszky Marton , Schintlmeister Arno , Schmid Markus C. , Hanson Buck T. , Shterzer Naama , Mizrahi Itzhak , Rauch Isabella , Decker Thomas , Bocklitz Thomas , Popp Jürgen , Gibson Christopher M. , Fowler Patrick W. , Huang Wei E. , Wagner Michael
Published: December 2014

Significance

Measuring activity patterns of microbes in their natural environment is essential for understanding ecosystems and the multifaceted interactions of microorganisms with eukaryotes. In this study, we developed a technique that allows fast and nondestructive activity measurements of microbial communities on a single-cell level. Microbial communities were amended with heavy water (D
2
O), a treatment that does not change the available substrate pool. After incubation, physiologically active cells are rapidly identified with Raman microspectroscopy by measuring cellular D incorporation. Using this approach, we characterized the activity patterns of two dominant microbes in mouse cecum samples amended with different carbohydrates and discovered previously unidentified bacteria stimulated by mucin and/or glucosamine by combining Raman microspectroscopy and optical tweezer-based sorting.
The polarity of myxobacterial gliding is regulated by direct interactions between the gliding motors and the Ras homolog MglA
Authors: Nan Beiyan , Bandaria Jigar N. , Guo Kathy Y. , Fan Xue , Moghtaderi Amirpasha , Yildiz Ahmet , Zusman David R.
Published: December 2014

Significance

The bacterium
Myxococcus xanthus
moves on surfaces by directed gliding motility. MglA, a Ras family GTPase, regulates cell polarity in
M. xanthus
; However, little is known about how MglA establishes cell polarity during gliding, because gliding motors move simultaneously in opposite directions. We found that MglA interacts with the gliding motors directly and is localized in a decreasing intracellular gradient. Furthermore, the motors tend to reverse their moving direction at locations where the activity of MglA is high. Our data suggest that biased reversals along the MglA gradient make the motors moving toward the lagging cell poles less likely to reverse, generating stronger forward propulsion. Thus, bacterial cells, like eukaryotic cells, can use Ras homolog localization to establish cellular polarity.
Inhibition of soluble epoxide hydrolase modulates inflammation and autophagy in obese adipose tissue and liver: Role for omega-3 epoxides
Authors: López-Vicario Cristina , Alcaraz-Quiles José , García-Alonso Verónica , Rius Bibiana , Hwang Sung H. , Titos Esther , Lopategi Aritz , Hammock Bruce D. , Arroyo Vicente , Clària Joan
Published: December 2014

Significance

Our study demonstrates that stabilization of cytochrome P-450 epoxides derived from omega-3 polyunsaturated fatty acids through inhibition of the inactivating enzyme soluble epoxide hydrolase (sEH) exerts beneficial actions in counteracting metabolic disorders associated with obesity. In addition, our study sheds more light on the role of sEH in cellular homeostasis by providing evidence that omega-3 epoxides and sEH inhibition regulate autophagy and endoplasmic reticulum stress in insulin-sensitive tissues, especially the liver. Therefore, administration of a sEH inhibitor is a promising strategy to prevent obesity-related comorbidities.
Nitric oxide negatively regulates abscisic acid signaling in guard cells by S-nitrosylation of OST1
Authors: Wang Pengcheng , Du Yanyan , Hou Yueh-Ju , Zhao Yang , Hsu Chuan-Chih , Yuan Feijuan , Zhu Xiaohong , Tao W. Andy , Song Chun-Peng , Zhu Jian-Kang
Published: December 2014

Significance

Drought stress induces the accumulation of the plant stress hormone abscisic acid (ABA). ABA then quickly activates the protein kinase OST1/SnRK2.6 to phosphorylate a number of proteins in guard cells, resulting in stomatal closure to reduce transpirational water loss. How SnRK2.6 is deactivated and how ABA signaling may be desensitized are unclear. This study found that nitric oxide (NO) resulting from ABA signaling causes S-nitrosylation of SnRK2.6 at a cysteine residue close to the kinase catalytic site, which blocks the kinase activity. Dysfunction of S-nitrosoglutathione (GSNO) reductase causes GSNO overaccumulation in guard cells and ABA insensitivity in stomatal regulation. This work thus reveals how ABA-induced NO functions in guard cells to inactivate SnRK2.6 to negatively feedback regulate ABA signaling.
Appearance and disappearance of the mRNA signature characteristic of T
reg
cells in visceral adipose tissue: Age, diet, and PPARγ effects
Authors: Cipolletta Daniela , Cohen Paul , Spiegelman Bruce M. , Benoist Christophe , Mathis Diane
Published: December 2014

Significance

A unique population of Foxp3
+
CD4
+
regulatory T (T
reg
) cells resides in visceral adipose tissue of lean mice. VAT T
regs
are important regulators of local and systemic inflammation and metabolism. Here, we show that the VAT T
reg
signature is imposed early in life, well before the typical age-dependent expansion of the adipose-tissue T
reg
population. VAT T
regs
in obese mice lose the signature typical of lean individuals but gain an additional set of over- and underrepresented transcripts. In striking parallel to a pathway recently elucidated in adipocytes, the obese mouse VAT T
reg
signature depends on phosphorylation of a specific residue of PPARγ. These findings are important to consider in designing drugs to target type 2 diabetes and other features of the “metabolic syndrome.”
Development and Outcomes of a Text Messaging Tobacco Cessation Intervention with Urban Adolescents
Authors: Mason Michael J. , Campbell Leah , Way Thomas , Keyser-Marcus Lori , Benotsch Eric , Mennis Jeremy , Zhang Jing , King Laura , May James , Stembridge Daniel R.
Published: December 2014

Background

This paper describes the development of an urban adolescent text messaging tobacco cessation intervention and preliminary findings from a randomized, controlled trial. The authors successfully adapted a face-to-face intervention into a personalized, automated, and interactive 5-day texting protocol.

Methods

Respondent-driven sampling was used beginning at a community substance abuse facility. Seventy-two tobacco-dependent adolescents were randomized into an automated computer texting program that delivered either the experimental condition of 30 motivational interviewing– and social network counseling–based personalized messages or the attention control condition consisting of a texting program covering general (non–smoking-related) health habits. All teens were provided smartphones for the study and were assessed at baseline and at 1, 3, and 6 months post intervention. Analyses examined condition × time interactions.

Results

At 6 months, the experimental condition decreased the number of cigarettes smoked in the past 30 days, increased intentions not to smoke in the future, and increased peer social support compared with controls. Effect sizes were moderate to large.

Conclusions

These findings are unique, as they target urban adolescents with a mobile health format and add to the growing literature on the efficacy of text-delivered interventions.
Proximate Composition of Bioflocs in Culture Systems Containing Hybrid Red Tilapia Fed Diets with Varying Levels of Vegetable Meal Inclusion
Authors: López-Elías José Antonio , Moreno-Arias Angélica , Miranda-Baeza Anselmo , Martínez-Córdova Luis Rafael , Rivas-Vega Martha Elisa , Márquez-Ríos Enrique
Published: December 2014

Biofloc culture systems, which are based on the development of microorganisms that recycle inorganic nutrients and organic matter, may contribute to the nutrition of some farmed species. Juvenile red tilapia (Nile Tilapia Oreochromis niloticus × Mozambique Tilapia O. mossambicus) cultured in saltwater were fed pelleted diets in which 0, 33, 67, or 100% of the fish meal was substituted with a vegetable meal mix (corn, wheat, and sorghum meals). The proximate composition of the biofloc produced in the culture systems was evaluated. Four experimental diets and one control diet (isocaloric and isoproteic) were randomly assigned to 15 experimental tanks. Samples of biofloc were periodically collected to measure the total suspended solids, organic matter, and ash content and to determine the protein, lipid, and carbohydrate contents. At the end of the study, variables describing red tilapia production were determined. The biofloc volume, total suspended solids, ash, and organic matter showed significant differences among treatments, but carbohydrate (33.0–39.0%), lipid (2.6–3.5%), and protein (23.7–25.4%) levels were similar. No significant differences were observed in red tilapia survival, final biomass, or feed conversion ratio. We conclude that the substitution of fish meal with vegetable meal in the pelleted feed had no adverse effect on the production response of saltwater-cultured red tilapia.
A note on the transitive Hurwitz action on decompositions of parabolic Coxeter elements
Authors: Baumeister Barbara , Dyer Matthew , Stump Christian , Wegener Patrick
Published: December 2014

In this note, we provide a short and self-contained proof that the braid group on 

n
n

strands acts transitively on the set of reduced factorizations of a Coxeter element in a Coxeter group of finite rank 

n
n

into products of reflections. We moreover use the same argument to also show that all factorizations of an element in a parabolic subgroup of 

W
W

also lie in this parabolic subgroup.
Valley excitons in two-dimensional semiconductors
Authors: Yu Hongyi , Cui Xiaodong , Xu Xiaodong , Yao Wang
Published: December 2014

Monolayer group-VIB transition-metal dichalcogenides have recently emerged as a new class of semiconductors in the two-dimensional limit. The attractive properties include the visible range direct band gap ideal for exploring optoelectronic applications; the intriguing physics associated with spin and valley pseudospin of carriers which implies potentials for novel electronics based on these internal degrees of freedom; the exceptionally strong Coulomb interaction due to the two-dimensional geometry and the large effective masses. The physics of excitons, the bound states of electrons and holes, has been one of the most actively studied topics on these two-dimensional semiconductors, where the excitons exhibit remarkably new features due to the strong Coulomb binding, the valley degeneracy of the band edges and the valley-dependent optical selection rules for interband transitions. Here, we give a brief overview of the experimental and theoretical findings on excitons in two-dimensional transition-metal dichalcogenides, with focus on the novel properties associated with their valley degrees of freedom.
Risk Factors for Developing Active Tuberculosis After the Treatment of Latent Tuberculosis in Adults Infected With Human Immunodeficiency Virus
Authors: Amoakwa Kojo , Martinson Neil A. , Moulton Lawrence H. , Barnes Grace L. , Msandiwa Reginah , Chaisson Richard E.
Published: December 2014

Tuberculosis is the leading cause of death among adults infected with human immunodeficiency virus (HIV), and rates of tuberculosis remain high even after preventive therapy. Among 908 HIV-infected adults in a trial of preventive treatment, we found self-reported alcohol consumption, low baseline CD4 count, high baseline viral load, and tuberculin skin test size >15 mm as independent risk factors for incident tuberculosis.
Surgeon Procedure Volume and Complication Rates in Anterior Cervical Discectomy and Fusions
Authors: Cole Tyler , Veeravagu Anand , Zhang Michael , Ratliff John K.
Published: December 2014

Study Design:

Retrospective study using the MarketScan longitudinal database (2006–2010).

Objective:

Compare complication rates between groups of patients undergoing anterior cervical discectomy and fusion (ACDF) procedures performed by surgeons with high versus low mean annual ACDF volume.

Summary of Background Data:

Over the past decade the volume of ACDFs performed has increased, concurrent with greater appreciation of potential for associated complications. The effect of surgeon procedure volume on adverse events occurrence in the postoperative period has not been described.

Materials and Methods:

We evaluated the relationship between surgeon procedure volume and postoperative incidence of any complication using a multivariate logistic regression model. A total of 24,461 patients undergoing single and multiple level ACDFs were identified in the MarketScan database by Current Procedural Terminology coding. Annual surgeon volume was determined by tracking of anonymized surgeon identification numbers, with high-volume surgeons defined as those performing an average of at least 30 ACDF procedures annually.

Results:

Over 50% of unique surgeon identifiers reported <9 ACDF operations per year, whereas the highest decile reported a range of 44–101. High surgeon volume was protective for any complication [odds ratio (OR), 72; 95% confidence interval, 0.65–0.81; P<0.0001], with an adjusted number needed to harm of 44. Patients treated by high-volume physicians specifically had lower odds of dysphagia (2.22% vs. 3.08%; OR, 0.71; P<0.0013), neurological complications (0.33% vs. 0.64%; OR, 0.52; P<0.0107), new diagnosis of chronic pain (0.48% vs. 0.82%; OR, 0.58; P<0.0119), pulmonary complications (1.10% vs. 1.58%; OR, 0.69; P<0.0138), and other wound complications (0.06% vs. 0.22%; OR, 0.28; P<0.0242).

Conclusions:

We demonstrate a possible association between higher surgeon procedure volume and decreased postoperative complications after ACDF. There was no difference observed in need for revision surgery or readmission rates.