bluuebunny/crossref_metadata_2025 huggingface dataset:
Sensitivity analysis of scanning microwave microscopy for nano-scale dopant measurements in Si
Authors: Torigoe Kazuhisa , Arita Makoto , Motooka Teruaki
Published: November 2012

We analyzed the sensitivity of scanning microwave microscopy (SMM) for doping concentration measurements in n-type Si based on the conventional equivalent-circuit model combined with numerical simulations of carrier distributions in metal-oxide-semiconductor capacitors. The minimum detectable change in capacitance was estimated to be 0.26 aF for the amplitude of the applied 17 GHz microwave voltage of 0.3 V. Possible measurable range of electron concentrations in Si was found to be 1015–1020 cm−3 with ∼10%–1% accuracy by using nano-scale flat-shaped tips for SMM measurements.
On the eddy-wave crossover and bottleneck effect in He III-B superfluid turbulence
Authors: Thiagalingam Ilango , Sagaut Pierre
Published: November 2012

An eddy damped quasi-normal Markovian closure model coupled to a differential approximation model suggested in L’vov, Nazarenko, and Rudenko [“Gradual eddy-wave crossover in superfluid turbulence,” J. Low Temp. Phys. 153, 140 (2008)10.1007/s10909-008-9844-0] is proposed to simulate the full unsteady dynamics of superfluid turbulence from large-scale hydrodynamic eddy motion to Kelvin waves that occur on quantized vortices in He III-B at very low temperature. The present model accounts for eddy-wave interactions over crossover scales, and coupling with the two existing models for the Kelvin wave cascade (L’vov and Nazarenko model [V. S L’vov and S. Nazarenko, “Spectrum of Kelvin wave turbulence in superfluids,” JETP Lett. 91, 428–434 (2010)10.1134/S002136401008014X] or Kozik and Svistunov model [E. Kozik and B. Svistunov, “Kelvin wave cascade and decay of superfluid turbulence,” Phys. Rev. Lett. 92, 035301 (2004)10.1103/PhysRevLett.92.035301]), are considered. Hydrodynamic kinetic energy spectrum and Kelvin wave energy spectrum are solved separately, allowing for a deep insight into flow physics. A detailed analysis of the bottleneck phenomena is performed thanks to a systematic investigation of the crossover region and the Kelvin cascade model. It is observed that both the shape and the width of the bottleneck region are governed by the eddy-wave interaction model. It is concluded that the bottleneck is robust in the sense that it is observed in all cases, but that a detailed description escapes both present direct numerical simulation and experimental capabilities.
The evolution of a localized nonlinear wave of the Kelvin–Helmholtz instability with gravity
Authors: Orazzo Annagrazia , Hoepffner Jérôme
Published: November 2012

At the interface between two fluids of different density and in the presence of gravity, there are well known periodic surface waves which can propagate for long distances with little attenuation, as it is for instance the case at the surface of the sea. If wind is present, these waves progressively accumulate energy as they propagate and grow to large sizes—this is the Kelvin–Helmholtz instability. On the other hand, we show in this paper that for a given wind strength, there is potential for the growth of a localized nonlinear wave. This wave can reach a size such that the hydrostatic pressure drop from top to bottom equals the stagnation pressure of the wind. This process for the disruption of the flat interface is localized and nonlinear. We study the properties of this wave using numerical simulations of the Navier–Stokes equations.
Large eddy simulation of controlled transition to turbulence
Authors: Sayadi Taraneh , Moin Parviz
Published: November 2012

Large eddy simulation of H- and K-type transitions in a spatially developing zero-pressure-gradient boundary layer at Ma∞ = 0.2 is investigated using several subgrid scale (SGS) models including constant coefficient Smagorinsky and Vreman models and their dynamic extensions, dynamic mixed scale-similarity, dynamic one-equation kinetic energy model, and global coefficient Vreman models. A key objective of this study is to assess the capability of SGS models to predict the location of transition and the skin friction throughout the transition process. The constant coefficient models fail to detect transition, but the dynamic procedure allows for a negligible turbulent viscosity in the early transition region. As a result, the “point” of transition is estimated correctly. However, after secondary instabilities set in and result in the overshoot in the skin friction profile, all models fail to produce sufficient subgrid scale shear stress required for the correct prediction of skin friction and the mean velocity profile. The same underprediction of skin friction persists into the turbulent region. Spatially filtered direct numerical simulation data in the same boundary layers are used to provide guidelines for SGS model development and validation.
Diffusion of water and selected atoms in DMPC lipid bilayer membranes
Authors: Hansen F. Y. , Peters G. H. , Taub H. , Miskowiec A.
Published: November 2012

Molecular dynamics simulations have been used to determine the diffusion of water molecules as a function of their position in a fully hydrated freestanding 1,2-dimyristoyl-sn-glycero-3-phosphorylcholine (DMPC) bilayer membrane at 303 K and 1 atm. The diffusion rate of water in a ∼10 Å thick layer just outside the membrane surface is reduced on average by a factor of ∼2 relative to bulk. For water molecules penetrating deeper into the membrane, there is an increasing reduction in the average diffusion rate with up to one order of magnitude decrease for those deepest in the membrane. A comparison with the diffusion rate of selected atoms in the lipid molecules shows that ∼6 water molecules per lipid molecule move on the same time scale as the lipids and may therefore be considered to be tightly bound to them. The quasielastic neutron scattering functions for water and selected atoms in the lipid molecule have been simulated and compared to observed quasielastic neutron scattering spectra from single-supported bilayer DMPC membranes.
Ab initio simulation of hydrogen bonding in ices under ultra-high pressure
Authors: Tian Linan , Kolesnikov Alexander I. , Li Jichen
Published: November 2012

In this article, as continuation of the previous publication (P. Zhang, L. Tian, Z. P. Zhang, G. Shao, and J. C. Li, J. Chem. Phys. 137, 044504 (2012))10.1063/1.4736853, we report a series of computational simulation results for ices using ab initio DFT methods. The results not only reproduced the main feature of inelastic neutron scattering spectra for ice Ih, but also other phases of ice such as VII and VIII. Furthermore, pressure dependent simulations for ice I and VIII have led us to obtain the spectra for the symmetrical structure of ice X. The transition from normal ice to the symmetrical form shows an extraordinary behaviour of H-bonding in term of vibrations associated with inter- and intra-molecular bonds, revealing a range of phenomena which was not seen before.
A combined crossed-beam and theoretical study of the reaction dynamics of O(3P) + C2H3 → C2H2 + OH: Analysis of the nascent OH products with the preferential population of the Π(A′) component
Authors: Park Min-Jin , Jang Su-Chan , Choi Jong-Ho
Published: November 2012

The gas-phase reaction dynamics of ground-state atomic oxygen [O(3P) from the photo-dissociation of NO2] with vinyl radicals [C2H3 from the supersonic flash pyrolysis of vinyl iodide, C2H3I] has been investigated using a combination of high-resolution laser-induced fluorescence spectroscopy in a crossed-beam configuration and ab initio calculations. Unlike the previous gas-phase bulk kinetic experiments by Baulch et al. [J. Phys. Chem. Ref. Data 34, 757 (2005)]10.1063/1.1748524, a new exothermic channel of O(3P) + C2H3 → C2H2 + OH (X 2Π: υ″ = 0) has been identified for the first time, and the population analysis shows bimodal nascent rotational distributions of OH products with low- and high-N″ components with a ratio of 2.4:1. No spin-orbit propensities were observed, and the averaged ratios of Π(A′)/Π(A″) were determined to be 1.66 ± 0.27. On the basis of computations at the CBS-QB3 theory level and comparison with prior theory, the microscopic mechanisms responsible for the nascent populations can be understood in terms of two competing dynamical pathways: a direct abstraction process in the low-N″ regime as the major pathway and an addition-complex forming process in the high-N″ regime as the minor pathway. Particularly, during the bond cleavage process of the weakly bound van der Waals complex C2H2—OH, the characteristic pathway from the low dihedral-angle geometry was consistent with the observed preferential population of the Π(A′) component in the nascent OH products. A molecular-level discussion of the reactivity, mechanism, and dynamical features of the title reaction are presented together with a comparison to gas-phase oxidation reactions of a series of prototypical hydrocarbon radicals.
Local order and dynamic properties of liquid AuxSi1−x alloys by molecular dynamics simulations
Authors: Jakse N. , Nguyen T. L. T. , Pasturel A.
Published: November 2012

Molecular dynamics simulations are performed to examine structural and dynamic properties of liquid Au–Si alloys around the eutectic composition, with interactions described via a modified embedded-atom model suitable for the liquid properties. The local structure as defined by the partial pair-correlation functions, coordination numbers, and partial structure factors is found to display a strong evolution with composition. In addition, a structural study using a three-dimensional pair-analysis technique evidences a strong evolution of the icosahedral short-range order over the range of concentrations, 0 < xSi < 0.5. In examining the dynamic properties of these alloys, we show a strong interplay between the structural changes and the evolution of the self-diffusion coefficients as a function of composition.
Anisotropic transport properties of zinc-blend ZnTe/CrTe heterogeneous junction nanodevices
Authors: Yao Wei , Yao K. L. , Gao G. Y. , Zhu S. C. , Fu H. H.
Published: November 2012

Motivated by the molecular-beam epitaxial growth of zinc-blend-type CrTe thin films on ZnTe, we present a theoretical study on the spin-polarized transport properties of ZnTe/CrTe p-n junction as spin diode and CrTe/ZnTe/CrTe magnetic tunnel junction for (001) and (011) surfaces. Both ZnTe(001)/CrTe(001) and ZnTe(011)/CrTe(011) p-n junctions show excellent spin diode effect, the majority spin current of positive voltage is much larger than that of negative voltage and the minority spin current is absolutely inhibited. The ZnTe(001)/CrTe(001) p-n junction has lower “turn off” current and higher rectification ratio (about 105) than the ZnTe(011)/CrTe(011) which shows obvious anisotropy. We also find that the tunneling magneto resistance ratio of the CrTe/ZnTe/CrTe magnetic tunnel junction is up to about 4 × 109%.
Nanotwins and stacking faults in high-strength epitaxial Ag/Al multilayer films
Authors: Bufford D. , Bi Z. , Jia Q. X. , Wang H. , Zhang X.
Published: November 2012

Epitaxial Ag/Al multilayer films have high hardness (up to 5.5 GPa) in comparison to monolithic Ag and Al films (2 and 1 GPa). High-density nanotwins and stacking faults appear in both Ag and Al layers, and stacking fault density in Al increases sharply with decreasing individual layer thickness, h. Hardness increases monotonically with decreasing h, with no softening. In comparison, epitaxial Cu/Ni multilayers reach similar peak hardness when h ≈ 5 nm, but soften at smaller h. High strength in Ag/Al films is primarily a result of layer interfaces, nanotwins, and stacking faults, which are strong barriers to dislocation transmission.
Power-law and logarithmic relaxations of hydrated proteins: A molecular dynamics simulations study
Authors: Kämpf K. , Klameth F. , Vogel M.
Published: November 2012

We use molecular dynamics simulations to study anomalous internal protein dynamics observed for the backbone atoms of hydrated elastin and hydrated myoglobin in the picoseconds and nanoseconds regimes. The anomalous dynamics manifests itself in a sublinear increase of the atomic mean square displacements and in a power-law or logarithmic-like decay of correlation functions. We find that several, but not all, observations can be described in the frameworks of rugged potential-energy landscape and fractional Fokker-Planck approaches, in particular, a fractional Ornstein-Uhlenbeck process. Furthermore, mode-coupling theory allows us to rationalize findings at ambient temperatures, but there are deviations between theoretical predictions and simulation results related to the anomalous dynamics at cryogenic temperatures. We argue that the observations are consistent with a scenario where a broad β-relaxation peak shifts through the picoseconds and nanoseconds regimes when cooling from 300 to 200 K, say. Inspection of trajectories of consecutive nitrogen atoms along the protein backbone reveals that correlated forward-backward jumps, which exhibit a substantial degree of cooperativity, are a key feature of the anomalous dynamics.
Surface concentration dependent structures of iodine on Pd(110)
Authors: Göthelid Mats , Tymczenko Michael , Chow Winnie , Ahmadi Sareh , Yu Shun , Bruhn Benjamin , Stoltz Dunja , von Schenck Henrik , Weissenrieder Jonas , Sun Chenghua
Published: November 2012

We use photoelectron spectroscopy, low energy electron diffraction, scanning tunneling microscopy, and density functional theory to investigate coverage dependent iodine structures on Pd(110). At 0.5 ML (monolayer), a c(2 × 2) structure is formed with iodine occupying the four-fold hollow site. At increasing coverage, the iodine layer compresses into a quasi-hexagonal structure at 2/3 ML, with iodine occupying both hollow and long bridge positions. There is a substantial difference in electronic structure between these two iodine sites, with a higher electron density on the bridge bonded iodine. In addition, numerous positively charged iodine near vacancies are found along the domain walls. These different electronic structures will have an impact on the chemical properties of these iodine atoms within the layer.
Guided-mode quantum efficiency: A novel optoelectronic characterization technique
Authors: Dissanayake D. M. N. M. , Ashraf A. , Pang Y. , Eisaman M. D.
Published: November 2012

We demonstrate a novel, multi-purpose optoelectronic characterization technique to quantify light trapping and photoinduced charge generation and extraction in photovoltaics and other multilayer thin-film optoelectronic devices. The technique measures the photogenerated current created via the selective evanescent coupling of incident light into each of the guided modes of an optoelectronic device. In analogy to the internal quantum efficiency commonly used to characterize photovoltaics (the ratio of photogenerated electrons extracted from the device to photons absorbed by the device for normally incident light), we define the guided-mode internal quantum efficiency (GIQE) as the ratio of photogenerated electrons extracted from the device to the photons absorbed by the device for a specific guided mode. We complement the measurement of GIQE with computational modeling to calculate the electromagnetic field distribution within the various layers of the device, enabling us to separate the contribution to the GIQE of the absorption in the photoactive layer from parasitic absorption in other layers. By separately quantifying the quantum efficiency of each guided mode, this technique enables improved optimization and design of optoelectronic devices, including photovoltaics that utilize waveguiding and light-trapping. Additionally, since the electromagnetic field of each guided mode has a unique spatial distribution within the photoactive layer, this technique also provides insight into the spatial distributions of charge-carrier extraction, regions of disorder, trap states, and defects within the photoactive layer.
Outer synchronization between two complex dynamical networks with discontinuous coupling
Authors: Sun Yongzheng , Li Wang , Zhao Donghua
Published: November 2012

In this paper, we study the outer synchronization between two complex networks with discontinuous coupling. Sufficient conditions for complete outer synchronization and generalized outer synchronization are obtained based on the stability theory of differential equations. The theoretical results show that two networks can achieve outer synchronization even if two networks are switched off sometimes and the speed of synchronization is proportional to the on-off rate. Finally, numerical examples are examined to illustrate the effectiveness of the analytical results.
Convergence time and speed of multi-agent systems in noisy environments
Authors: Sun Yongzheng , Li Wang , Zhao Donghua
Published: November 2012

In this paper, the finite-time consensus problem of noise-perturbed multi-agent systems with fixed and switching undirected topologies is investigated. A continuous non-Lipschitz protocol for realizing stochastic consensus in a finite time is proposed. Based on the finite-time stability theory of stochastic differential equations, sufficient conditions are obtained to ensure finite-time stochastic consensus of multi-agent systems. An analytical upper bound for the convergence time is given. The effects of control parameters and noise intensity on convergence speed and time are also analyzed. Furthermore, numerical examples are provided to illustrate the effectiveness of the theoretical results.
Kinetic description of electron plasma waves with orbital angular momentum
Authors: Mendonça J. T.
Published: November 2012

We describe the kinetic theory of electron plasma waves with orbital angular momentum or twisted plasmons. The conditions for a twisted Landau resonance to exist are established, and this concept is introduced for the first time. Expressions for the kinetic dispersion relation and for the electron Landau damping are derived. The particular case of a Maxwellian plasma is examined in detail. The new contributions to wave dispersion and damping due the orbital angular momentum are discussed. It is shown that twisted plasmons can be excited by rotating electron beams.
L- and M-shell absorption measurements of radiatively heated Fe plasma
Authors: Zhang Jiyan , Li Hang , Zhao Yang , Xiong Gang , Yuan Zheng , Zhang Haiying , Yang Guohong , Yang Jiamin , Liu Shenye , Jiang Shaoen , Ding Yongkun , Zhang Baohan , Zheng Zhijian , Xu Yan , Meng Xujun , Yan Jun
Published: November 2012

Measurements of iron-plasma absorption spectrum over 150–1200 eV photon energy range were reported at temperature T = (72 ± 4) eV. The electron temperature was diagnosed with the absorption spectrum of aluminum mixed with iron. The density was not diagnosed directly but obtained from a radiative hydrodynamic simulation with the Multi-1D code. The broad photon energy range enables simultaneous observation of the L-shell and M-shell transitions that dominate the radiation transport at this temperature. The spectrally resolved transmission data were compared to the detailed-configuration-accounting model calculations and reasonable agreement was found.
Propagation of surface hybrid modes on metallic cylindrical nanoshells
Authors: Bahari Ali , Amraie Elhame
Published: November 2012

Propagation of surface hybrid modes on a system consisting of metal-air-metal cylinder has been investigated theoretically. The effect of increasing the interwall spacing between two metals on plasmon dispersion relation is shown. The dispersion relation can lead to a simple equation for m = 0. Calculations show that the plasmon energy of this structure depends on the interwall spacing between two metals.
Artificial neural networks based prediction of performance and exhaust emissions in direct injection engine using castor oil biodiesel-diesel blends
Authors: Shojaeefard M. H. , Etghani M. M. , Akbari M. , Khalkhali A. , Ghobadian B.
Published: November 2012

In this study, the performance and emission characteristics of a direct injection diesel engine using castor oil biodiesel (COB)-diesel blended fuels were investigated experimentally and then predicted by artificial neural networks. For this aim, castor oil was converted to its biodiesel via transesterification approach. Then, the effects of the biodiesel percentage in blend, engine load, and speed on brake power, brake specific fuel consumption (BSFC), nitrogen oxides (NOx), carbon dioxide (CO2), carbon monoxide (CO), and particle matter (PM) have been considered. Fuel blends with various percentages of biodiesel (0%, 5%, 10%, 15%, 20%, 25%, and 30%) at various engine speeds and loads were tested. The results indicated that blends of COB with diesel fuel provide admissible engine performance; on the other side, emissions decreased so much. Two types of neural networks, a group method of data handling (GMDH) and feed forward were used for modeling of the diesel engine to predict brake power, BSFC, and exhaust emissions such as CO, CO2, NOx, and PM values. The comparison results demonstrate the superiority of the feed forward neural network models over GMDH type models in terms of the statistical measures in the training and testing data but in the number of hidden neurons and model simplicity, GMDH models are preferred.
Communication: Oscillated band gaps of B/N-codoped α-graphyne
Authors: Deng Xiaohui , Si Mingsu , Dai Jiayu
Published: November 2012

The physical mechanism for the electronic structures tuning and band gap opening of α-graphyne are investigated from the first principles calculations. The pathway of using B and N atoms to codope into graphyne is proposed. After codoping, B atom plays a role of hole doping and N atom acts as electron doping. In codoped graphyne, the Fermi energy returns around the Dirac point and a gap is introduced. Interestingly, the opened gaps oscillate periodically with the increasing distances between B and N atoms with the gap from 0.07 eV to 0.50 eV, which is caused by the breaking sublattice symmetry.
A common rule for decision making in animal collectives across species
Authors: Arganda Sara , Pérez-Escudero Alfonso , de Polavieja Gonzalo G.
Published: November 2012

A diversity of decision-making systems has been observed in animal collectives. In some species, choices depend on the differences of the numbers of animals that have chosen each of the available options, whereas in other species on the relative differences (a behavior known as Weber’s law), or follow more complex rules. We here show that this diversity of decision systems corresponds to a single rule of decision making in collectives. We first obtained a decision rule based on Bayesian estimation that uses the information provided by the behaviors of the other individuals to improve the estimation of the structure of the world. We then tested this rule in decision experiments using zebrafish (
Danio rerio
), and in existing rich datasets of argentine ants (
Linepithema humile
) and sticklebacks (
Gasterosteus aculeatus
), showing that a unified model across species can quantitatively explain the diversity of decision systems. Further, these results show that the different counting systems used by animals, including humans, can emerge from the common principle of using social information to make good decisions.
Priming with real motion biases visual cortical response to bistable apparent motion
Authors: Zhang Qing-fang , Wen Yunqing , Zhang Deng , She Liang , Wu Jian-young , Dan Yang , Poo Mu-ming
Published: November 2012

Apparent motion quartet is an ambiguous stimulus that elicits bistable perception, with the perceived motion alternating between two orthogonal paths. In human psychophysical experiments, the probability of perceiving motion in each path is greatly enhanced by a brief exposure to real motion along that path. To examine the neural mechanism underlying this priming effect, we used voltage-sensitive dye (VSD) imaging to measure the spatiotemporal activity in the primary visual cortex (V1) of awake mice. We found that a brief real motion stimulus transiently biased the cortical response to subsequent apparent motion toward the spatiotemporal pattern representing the real motion. Furthermore, intracellular recording from V1 neurons in anesthetized mice showed a similar increase in subthreshold depolarization in the neurons representing the path of real motion. Such short-term plasticity in early visual circuits may contribute to the priming effect in bistable visual perception.
Diversity, religiosity, and spirituality in the workplace
Authors: Schaeffer Charles B. , Mattis Jacqueline S.
Published: November 2012

In this paper, we consider the ways in which attention to diversity and to the sociopolitical conditions that lead to discrimination and marginalization would complicate extant discourses about workplace spirituality. We posit that critical attention to differences in social identity,
social location, and attendant power relationships would force scholars in this area of study to reconsider several foundational questions: first, attention to the lived experience of people from diverse backgrounds and histories would force us to broaden our view and definition of work. Second,
we would be compelled to think more broadly and more critically about what we define as workplaces. Third, attending in critical ways to matters of diversity would compel us to think about religiosity and spirituality as landscapes of diversity. Finally, we would be compelled to consider theoretical
approaches that would allow us to explore the reality that the workplace is a space in which the complex sociohistorical and sociopolitical dynamics of race, gender, class, immigrant status, sexuality, and other identity statuses are reproduced, and to understand the ways that individuals
and institutions use religion and spirituality to engage, cope with, or obscure those complexities. We address each of these issues in turn, and we conclude with a brief set of recommendations for future work in the field.
Zen and the creative management of dilemmas
Authors: Low Albert , Purser Ronald
Published: November 2012

The management of dilemmas can be enhanced by learning from Zen Buddhism, particularly the meditative practice of working on koans. Zen koans are the recorded sayings, teachings, and encounter dialogs between Buddhist masters and students. The paper begins by first examining the nature of dilemmas and how various modes of thinking differ in their effectiveness in achieving a creative reconciliation. Next, Zen koan practice is explored as a means of providing insights into the human capacities required to perceive and resolve organizational dilemmas. The state of the mind required to resolve Zen koans is only different in degree from the mental capacities managers need to develop for reconciling organizational dilemmas. Next, the capacities of mind required to reconcile dilemmas is examined, which involves a new logic of ambiguity that is the basis of creative insight. Finally, the Zen koan pedagogy and Zen training are discussed in terms of its implications for research and management education.
Methods for Rearing Golden Shiner Fry in a Recirculating Aquaculture System
Authors: Tye Marc
Published: November 2012

Golden Shiners Notemigonus crysoleucas are one of the most popular baitfishes in the United States. Many states have seasonal shortages of Golden Shiners due to fish importation laws, short growing seasons, disputes over wetland usage, and harvesting laws regarding waters containing nonnative invasive species. Limited supply, favorable wholesale price, and certain biological characteristics of Golden Shiners make this species a potentially economically viable candidate for growing commercially in a recirculating aquaculture system (RAS). If effective procedures can be developed, Golden Shiners could be produced in-state without risking the threat of bringing in nonnative invasive species or potentially hazardous infectious diseases, while supplying fishermen with sought-after bait 12 months of the year. Golden Shiner eggs were placed into four separate tanks in a RAS and fed nonhatching decapsulated brine shrimp cysts. The number of newly hatched fry were counted daily, starting on day 6 postfertilization; this provided a base for survival rates calculated at the end of the study. Survival rates after the 32-d experiment for the four tanks were 100%, 89%, 96%, and 70%. These results suggest that similar survival rates can be achieved in a large-scale production system, and thus provide pond culturists with fry earlier in the growing season or support grow-out operations for Golden Shiner production.
Rapid communication: Selective cues to forget can fail to cause forgetting
Authors: Storm Benjamin C. , Koppel Rebecca H. , Wilson Brittany M.
Published: November 2012

Recent research has found that individuals can selectively forget a subset of items through directed forgetting. The goal of the present study was to replicate this selective directed forgetting effect and elucidate its underlying mechanisms. Unfortunately, results from four experiments failed to find any evidence of selective directed forgetting. Participants failed to forget any items when instructed to forget a subset of items from a first list before learning a second list. Participants were only successful in forgetting items from the first list when they were instructed to forget all items from the first list before learning the second list.
Vibrational Spectra and Quantum Calculations of Ethylbenzene
Authors: Wang Jian , Qiu Xue-jun , Wang Yan-mei , Zhang Song , Zhang Bing
Published: November 2012

Normal vibrations of ethylbenzene in the first excited state have been studied using resonant two-photon ionization spectroscopy. The band origin of ethylbenzene of S1←S0 transition appeared at 37586 cm−1. A vibrational spectrum of 2000 cm−1 above the band origin in the first excited state has been obtained. Several chain torsions and normal vibrations are obtained in the spectrum. The energies of the first excited state are calculated by the time-dependent density function theory and configuration interaction singles (CIS) methods with various basis sets. The optimized structures and vibrational frequencies of the S0 and S1 states are calculated using Hartree-Fock and CIS methods with 6-311++G(2d,2p) basis set. The calculated geometric structures in the S0 and S1 states are gauche conformations that the symmetric plane of ethyl group is perpendicular to the ring plane. All the observed spectral bands have been successfully assigned with the help of our calculations.
Solvent Effects on Spectral Property and Dipole Moment of the Lowest Excited State of Coumarin 343 Dye
Authors: Jiang Li-lin , Liu Wei-long , Song Yun-fei , He Xing , Wang Yang , Wu Hong-lin , Yang Yan-qiang
Published: November 2012

Steady-state absorption and fluorescence spectra, and time-resolved fluorescence spectra of coumarin 343 (C343) were measured in different solvents. The effect of the solvent on the spectral properties and dipole moment of the lowest excited state of C343 were investigated. It was found that the absorption and fluorescence spectra red-shifted slightly and strongly with increasing solvent polarity, respectively, because the charge distribution of the excited state leaded to the increasing difference between the absorption and fluorescence spectra with increasing solvent polarity. The dipole moment of the lowest excited state of C343 was determined from solvatochromic measurements and the quantum chemical calculation, and the results obtained from these two methods were fully consistent. Investigations of the time-resolved fluorescence of C343 in different solvents indicated that the fluorescence lifetimes increased nearly linearly with increasing solvent polarity from 3.09 ns in toluene to 4.45 ns in water. This can be ascribed to the intermolecular hydrogen bonding interactions between C343 and hydrogen donating solvents.
Continuous Flow Reactor for Hydroxylation of Benzene to Phenol by Hydrogen Peroxide
Authors: Zhang Li , Liu Hui-hui , Li Gui-ying , Hu Chang-wei
Published: November 2012

The direct hydroxylation of benzene to phenol catalyzed by activated carbon-supported Fe (Fe/AC) in acetonitrile using H2O2 as the oxidant was studied in a continuous flow reactor. Results showed that the continuous operation could obtain high phenol yield of 28.1%, coupled with the turnover frequency of 3 h−1, and high selectivity of 98% under mild condition. The catalyst was characterized by N2 adsorption/desorption, Boehm titration, X-ray photoelectron spectra, and Fourier transform infrared spectroscopy. It was observed that iron may interact with the carboxyl group forming iron-carboxylate like species, which act as the active phase. The apparent activation energy obtained by fitting an Arrhenius model to the experimental data was 13.4 kJ/mol. The reaction order was calculated to be about 1, 0.2 for benzene and 0.7 for H2O2.
Lensing and dynamics in two simple steps
Authors: Agnello A. , Auger M. W. , Evans N. W.
Published: November 2012

We present a ready-to-use method to constrain the density distribution in spherically symmetric early-type galaxy lenses. Assuming a power-law density profile, then joint use of the virial theorem and the lens equation yields simple formulae for the power-law index (or logarithmic density gradient). Any dependence on orbital anisotropy can be tightly constrained or even erased completely. Our results rely just on surface brightnesses and line-of-sight kinematics, making deprojection unnecessary. We revisit three systems that have already been examined in the literature (the Cosmic Horseshoe, the Jackpot and B1608+656) and provide our estimates. Finally, we show that the method yields a good approximation for the density profile even when the true profile is a broken power law, albeit with a mild bias towards isothermality.
Nematode-Induced Endoreduplication in Plant Host Cells: Why and How?
Authors: de Almeida Engler Janice , Gheysen Godelieve
Published: November 2012

Plant-parasitic root-knot and cyst nematodes have acquired the ability to induce remarkable changes in host cells during the formation of feeding sites. Root-knot nematodes induce several multinucleate giant cells inside a gall whereas cyst nematodes provoke the formation of a multinucleate syncytium. Both strategies impinge on the deregulation of the cell cycle, involving a major role for endoreduplication. This review will first describe the current knowledge on the control of normal and aberrant cell cycles. Thereafter, we will focus on the role of both cell-cycle routes in the transformation process of root cells into large and highly differentiated feeding sites as induced by the phytoparasitic root-knot and cyst nematodes.
Focus on Molecular Plant-Nematode and Plant-Insect Interactions
Authors: Hogenhout Saskia , Mitchum Melissa , Smant Geert
Published: November 2012

Sedentary plant-parasitic nematodes engage in a long-lasting and intimate relationship with their host plant. This interaction starts in the soil when freshly hatched infective juveniles are attracted to specific parts of a host plant root system. Little is known of what determines the attractiveness of host plant roots, but a mix of biochemical and structural cues from specific host tissues in the roots likely triggers invasive behavior in nematodes. Similarly to nematodes, phloem-feeding aphids and other piercing-sucking (hemipteran) insects must establish close associations with their host plants in order to modulate plant cellular processes to promote feeding and reproduction. This focus issue on molecular interactions between plants and different representatives of the animal kingdom sheds light on recent developments and offers a platform for exciting new data in this field. We are grateful to all the authors for their diverse contributions and for making this focus issue possible.

Click on Next Article or Table of Contents above to view the articles in this Focus Issue. (From the Mobile site, go to the MPMI January 2013 issue.)
Steady dark solitary flexural gravity waves
Authors: Milewski Paul A. , Vanden-Broeck Jean-Marc , Wang Zhan
Published: November 2012

The nonlinear Schrödinger (NLS) equation describes the modulational limit of many surface water wave problems. Dark solitary waves of the NLS equation asymptote to a constant in the far field and have a localized decrease to zero amplitude at the origin, corresponding to water wave solutions that asymptote to a uniform periodic Stokes wave in the far field and decreasing oscillations near the origin. It is natural to ask whether these dark solitary waves can be found in the irrotational Euler equations. In this paper, we find such solutions in the context of flexural-gravity waves, which are often used as a model for waves in ice-covered water. This is a situation in which the NLS equation predicts
steadily
travelling dark solitons. The solution branches of dark solitons are continued, and one branch leads to fully localized solutions at large amplitudes.
In situsynchrotron wide-angle X-ray diffraction investigation of fatigue cracks in natural rubber
Authors: Rublon Pierre , Huneau Bertrand , Saintier Nicolas , Beurrot Stéphanie , Leygue Adrien , Verron Erwan , Mocuta Cristian , Thiaudière Dominique , Berghezan Daniel
Published: November 2012

Natural rubber exhibits remarkable mechanical fatigue properties usually attributed to strain-induced crystallization. To investigate this phenomenon, an original experimental set-up that couples synchrotron radiation with a homemade fatigue machine has been developed. Diffraction-pattern recording is synchronized with cyclic loading in order to obtain spatial distributions of crystallinity in the sample at prescribed times of the mechanical cycles. Then, real-time measurement of crystallinity is permitted during uninterrupted fatigue experiments. First results demonstrate the relevance of the method: the set-up is successfully used to measure the crystallinity distribution around a fatigue crack tip in a carbon black filled natural rubber for different loading conditions.
Social influence and job choice decisions
Authors: Kulkarni Mukta , Nithyanand Siddharth
Published: November 2012

Purpose

Past research has largely portrayed job choice as a relatively rational and goal‐directed behavior where applicants make decisions contingent on organizational recruitment activities, or evaluations of job and organizational attributes. Research now informs us that job choice decisions may also be based on social comparisons and social influence. The purpose of this paper is to add to this body of knowledge by examining reasons why social influence is a key factor in job choice decisions of relatively young job seekers.

Design/methodology/approach

The study is based on in‐depth interview data from graduating seniors at an elite business school in India.

Findings

Respondents did not see themselves as acting based on social influence as much as they perceivedothersaround them to be. Reasons they noted forothers’ socially influenced job choice decisions were: peers and seniors are seen as more accessible and trustworthy than organizations; organizations do not share all and/or objective data, driving job seekers to other sources; job seekers are clueless and hence follow a “smart” herd; and job seekers make decisions for social status signaling. Respondents pointed to socially influenced job choices as being rational behaviors under certain conditions.

Research limitations/implications

Generalizability of findings may be limited to young job seekers or to the Indian context, and the authors encourage replication. The authors also acknowledge the importance of individual difference variables in job choice decisions, a factor not considered in the present research.

Practical implications

Given that job seekers rally around others’ notion of an attractive job or an organization, the paper outlines several implications for managerial practice.

Originality/value

This study, in a yet unexamined cultural context, points to the simultaneous and combined importance of normative and informational social determinants of job choice, bias blind spots in one's own job choice perceptions and decisions, gender specific socialization influences on job choices, and the notion of job fit in terms of fitment with expectations of important reference groups.
Evaluating the environments of residential care settings
Authors: Moos Rudolf H.
Published: November 2012

Purpose

The purpose of this paper is to review some research on the environmental characteristics of residential care settings.

Design/methodology/approach

The paper's approach is an integrative overview and formulation of a conceptual framework to understand and measure the key environmental domains of residential care programs.

Findings

The five major domains that comprise the characteristics of residential program are the institutional context, physical and architectural features, policies and services, aggregate resident and staff characteristics, and the social climate. The multiphasic environmental assessment procedure (MEAP), which systematically assesses these domains, shows that, for example, programs with better physical features tend to have better policy and program characteristics, more functionally able residents, more varied and experienced staff, and a more cohesive social climate.

Practical implications

The conceptual framework and assessment procedures can be used to provide useful information to help prospective residents and staff select appropriate residential care settings, to identify characteristics of settings most amenable to change, decide what changes would benefit residents and staff, and, by providing systematic feedback, help guide program improvement; and identify environmental features most closely associated with residents' quality of life and functional maintenance or improvement.

Originality/value

The paper presents a unique and innovative conceptualization of the environmental domains of residential care settings, along with a validated procedure to measure these domains.
A rural/urban comparison of psychiatric inpatient admissions in Ireland
Authors: Morrissey Karyn , Daly Antoinette , Clarke Graham , O'Donoghue Cathal , Ballas Dimitris
Published: November 2012

Purpose

There is a body of evidence that indicates mental illnesses are more prevalent in urban settings. However, to date no research has been carried out on the urban/rural incidence of mental illness in Ireland. This paper seeks to examine the micro level determinants of admissions to psychiatric hospitals between urban and rural areas.

Design/methodology/approach

Data from the National Psychiatric In‐patient Reporting System (NPIRS) and multivariate regression models are used.

Findings

Results from this analysis found that, in Ireland, rural residents had a higher probability of being admitted to a psychiatric hospital for schizophrenia and depression compared to urban residents.

Research limitations/implications

The results presented here are only applicable to individuals that have been admitted to a psychiatric hospital. Findings cannot be extrapolated to the general population. Future research will involve the simulation of mental health characteristics for the entire Irish population.

Originality/value

The analysis presented in the paper contributes to the current understanding of the social and spatial profile of psychiatric admissions in Ireland, whilst providing additional research to the international debate regarding urban/rural differentials in acute psychiatric hospital admissions.
Evaluating stress in natural populations of vertebrates: total CORT is not good enough
Authors: Breuner Creagh W. , Delehanty Brendan , Boonstra Rudy
Published: November 2012

Our goal in this review is to discuss how measures beyond simple quantification of total glucocorticoid levels are needed in comparative studies of stress. We need to measure corticosteroid binding globulin – CBG – and further downstream performance metrics to properly evaluate the significance and impact of stress in wild populations. We briefly cover the current literature, discuss methods that may enable detection of chronic stress and point to directions for future research to continue to clarify this field.

CBG may regulate access of hormones to tissues, but disagreement remains as to the functional importance of total vs. free vs. bound hormone in the plasma. Here we focus on recent studies providing solid evidence supporting the free hormone hypothesis. These studies unequivocally indicate that the biologically active fraction consists only of the portion that is free (not total levels in the blood). We also present the ‘reservoir hormone hypothesis’, indicating the relevance of CBG‐bound hormone in the plasma.

The vast majority of physiological studies on stress in natural populations only measure blood corticosterone or its faecal metabolites. However, downstream metrics (e.g. immune function, oxidative stress and body mass changes) can assess the physiological impact of the changes in corticosterone and CBG and ultimately of the adaptiveness of these changes. Here we will discuss some of the most promising factors that can be measured downstream of the plasma and the rationale for their measurement, how to do it, and an introduction to the evidence.

Although we draw on biomedical findings for some of this insight, we recognized that findings from a few mammalian laboratory species (primarily rats and mice) may not apply to the vast diversity of vertebrate species from fish to birds. In large measure we are still in the natural history phase of the accumulation of fundamental knowledge in terms of trying to extract general principles in the stress biology of natural populations. Our review outlines what is needed to lay the foundation for these principles.
Female ornaments revisited – are they correlated with offspring quality?
Authors: Nordeide Jarle T. , Kekäläinen Jukka , Janhunen Matti , Kortet Raine
Published: November 2012

The evolution and signalling content of female ornamentation has remained an enduring challenge to evolutionary biologists, despite the fact that secondary sexual characters are widespread in females. While females usually invest significant amounts of their resources, including carotenoids, in offspring, all the resources allocated to elaborate ornamentation reduce resources available for other purposes. This may in turn constrain female fitness leading to dishonest female signalling.

We review the literature for empirical studies on mutually ornamented species with conventional sex roles, by focusing on the association between female ornaments and quality of their offspring.

We found 43 papers where 33 (77%) are bird‐studies, nine (21%) are on fishes, and one (2%) is a lizard‐study. Nine of these report negative, 14 non‐existing, and 20 positive associations between female ornament and offspring quality. Eighteen of the bird studies (55%) show a positive association between the two traits investigated, whereas five (15%) of the studies report a negative association. The number of fish studies, although few, is skewed in the opposite direction with two (22%) and four (44%) studies supporting positive and negative association, respectively. A minority of studies on carotenoids‐based ornaments reports a positive association (4 of 18 studies, or 22%) between the traits, which is low compared to studies on non‐carotenoids‐based ornaments (16 of 25 studies, or 64%).

The above‐mentioned relative large number of studies with negative association, especially common in studies on fishes and in carotenoids‐based‐ornaments, challenges the generality of the direct selection hypothesis to account for female fineries. This is important because this hypothesis seems to have strong support in recent literature on the topic. In the present paper, we also propose possible explanations for the observed differences between taxa and suggest directions and ideas for future research on the evolution of female ornamentation.