bluuebunny/crossref_metadata_2025 huggingface dataset:
Stokes shift dynamics in (non-dipolar ionic liquid + dipolar solvent) binary mixtures: A semi-molecular theory
Authors: Pal Tamisra , Biswas Ranjit
Published: October 2014

A semi-molecular theory for studying composition dependent Stokes shift dynamics of a dipolar solute in binary mixtures of (non-dipolar ionic liquid + common dipolar solvent) is developed here. The theory provides microscopic expressions for solvation response functions in terms of static and dynamic structure factors of the mixture components and solute-solvent static correlations. In addition, the theory provides a framework for examining the interrelationship between the time dependent solvation response in and frequency dependent dielectric relaxation of a binary mixture containing electrolyte. Subsequently, the theory has been applied to predict ionic liquid (IL) mole fraction dependent dynamic Stokes shift magnitude and solvation energy relaxation for a dipolar solute, C153, in binary mixtures of an ionic liquid, trihexyltetradecylphosphonium chloride ([P14,666][Cl]) with a common dipolar solvent, methanol (MeOH). In the absence of suitable experimental data, necessary input parameters have been obtained from approximate methods. Dynamic shifts calculated for these mixtures exhibit a linear increase with IL mole fraction for the most part of the mixture composition, stressing the importance of solute-IL dipole-ion interaction. Average solvation rates, on the other hand, show a nonlinear IL mole fraction dependence which is qualitatively similar to what has been observed for such binary mixtures with imidazolium (dipolar) ILs. These predictions should be re-examined in suitable experiments.
Tribological interaction between polytetrafluoroethylene and silicon oxide surfaces
Authors: Uçar A. , Çopuroğlu M. , Baykara M. Z. , Arıkan O. , Suzer S.
Published: October 2014

We investigated the tribological interaction between polytetrafluoroethylene (PTFE) and silicon oxide surfaces. A simple rig was designed to bring about a friction between the surfaces via sliding a piece of PTFE on a thermally oxidized silicon wafer specimen. A very mild inclination (∼0.5°) along the sliding motion was also employed in order to monitor the tribological interaction in a gradual manner as a function of increasing contact force. Additionally, some patterns were sketched on the silicon oxide surface using the PTFE tip to investigate changes produced in the hydrophobicity of the surface, where the approximate water contact angle was 45° before the transfer. The nature of the transferred materials was characterized by X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). XPS results revealed that PTFE was faithfully transferred onto the silicon oxide surface upon even at the slightest contact and SEM images demonstrated that stable morphological changes could be imparted onto the surface. The minimum apparent contact pressure to realize the PTFE transfer is estimated as 5 kPa, much lower than reported previously. Stability of the patterns imparted towards many chemical washing processes lead us to postulate that the interaction is most likely to be chemical. Contact angle measurements, which were carried out to characterize and monitor the hydrophobicity of the silicon oxide surface, showed that upon PTFE transfer the hydrophobicity of the SiO2 surface could be significantly enhanced, which might also depend upon the pattern sketched onto the surface. Contact angle values above 100° were obtained.
Solution of the Korteweg-de Vries equation on the line with analytic initial potential
Authors: Melnikov Andrey
Published: October 2014

We present a theory of Sturm-Liouville non-symmetric vessels, realizing an inverse scattering theory for the Sturm-Liouville operator with analytic potentials on the line. This construction is equivalent to the construction of a matrix spectral measure for the Sturm-Liouville operator, defined with an analytic potential on the line. Evolving such vessels we generate Korteweg-de Vries (KdV) vessels, realizing solutions of the KdV equation. As a consequence, we prove the theorem as follows: Suppose that q(x) is an analytic function on $\mathbb {R}$R. Then there exists a closed subset $\Omega \subseteq \mathbb {R}^2$Ω⊆R2 and a KdV vessel, defined on Ω. For each $x\in \mathbb {R}$x∈R one can find Tx > 0 such that {x} × [ − Tx, Tx]⊆Ω. The potential q(x) is realized by the vessel for t = 0. Since we also show that if q(x, t) is a solution of the KdV equation on $\mathbb {R}\times [0,t_0)$R×[0,t0), then there exists a vessel, realizing it, the theory of vessels becomes a universal tool to study this problem. Finally, we notice that the idea of the proof applies to a similar existence of a solution for evolutionary nonlinear Schrödinger and Boussinesq equations, since both of these equations possess vessel constructions.
Probing the elastic response of microalga Scenedesmus dimorphus in dry and aqueous environments through atomic force microscopy
Authors: Warren K. M. , Mpagazehe J. N. , LeDuc P. R. , Higgs C. F.
Published: October 2014

With the re-emergence of microalgae as a replacement feedstock for petroleum-derived oils, researchers are working to understand its chemical and mechanical behavior. In this work, the mechanical properties of microalgae, Scenedesmus dimorphus, were investigated at the subcellular level to determine the elastic response of cells that were in an aqueous and dried state using nano-scale indentation through atomic force microscopy. The elastic modulus of single-celled S. dimorphus cells increased over tenfold from an aqueous state to a dried state, which allows us to better understand the biophysical response of microalgae to stress.
Effect of intermolecular potential on compressible Couette flow in slip and transitional regimes
Authors: Weaver Andrew B. , Venkattraman A. , Alexeenko Alina A.
Published: October 2014

The effect of intermolecular potentials on compressible, planar flow in slip and transitional regimes is investigated using the direct simulation Monte Carlo method. Two intermolecular interaction models, the variable hard sphere (VHS) and the Lennard-Jones (LJ) models, are first compared for subsonic and supersonic Couette flows of argon at temperatures of 40, 273, and 1,000 K, and then for Couette flows in the transitional regime ranging from Knudsen numbers (Kn) of 0.0051 to 1. The binary scattering model for elastic scattering using the Lennard-Jones (LJ) intermolecular potential proposed recently [A. Venkattraman and A. Alexeenko, “Binary scattering model for Lennard-Jones potential: Transport coefficients and collision integrals for non-equilibrium gas flow simulations,” Phys. Fluids 24, 027101 (2012)] is shown to accurately reproduce both the theoretical collision frequency in an equilibrium gas as well as the theoretical viscosity variation with temperature. The use of a repulsive-attractive instead of a purely repulsive potential is found to be most important in the continuum and slip regimes as well as in flows with large temperature variations. Differences in shear stress of up to 28% between the VHS and LJ models is observed at Kn=0.0051 and is attributed to differences in collision frequencies, ultimately affecting velocity gradients at the wall. For Kn=1 where the Knudsen layer expands the entire domain, the effect of the larger collision frequency in the LJ model relative to VHS diminishes, and a 7% difference in shear stress is observed.
Direct observation of both contact and remote oxygen scavenging of GeO2 in a metal-oxide-semiconductor stack
Authors: Fadida S. , Shekhter P. , Cvetko D. , Floreano L. , Verdini A. , Nyns L. , Van Elshocht S. , Kymissis I. , Eizenberg M.
Published: October 2014

In the path to incorporating Ge based metal-oxide-semiconductor into modern nano-electronics, one of the main issues is the oxide-semiconductor interface quality. Here, the reactivity of Ti on Ge stacks and the scavenging effect of Ti were studied using synchrotron X-ray photoelectron spectroscopy measurements, with an in-situ metal deposition and high resolution transmission electron microscopy imaging. Oxygen removal from the Ge surface was observed both in direct contact as well as remotely through an Al2O3 layer. The scavenging effect was studied in situ at room temperature and after annealing. We find that the reactivity of Ti can be utilized for improved scaling of Ge based devices.
Lattice thermal conductivity of filled skutterudites: An anharmonicity perspective
Authors: Geng Huiyuan , Meng Xianfu , Zhang Hao , Zhang Jian
Published: October 2014

We report a phenomenological model to calculate the high-temperature lattice thermal conductivity of filled skutterudite antimonides. The model needs no phonon resonant scattering terms. Instead, we assume that umklapp processes dominate the high-temperature phonon scattering. In order to represent the anharmonicity introduced by the filling atom, we introduce a Gaussian term into the relaxation time of the umklapp process. The developed model agrees remarkably well with the experimental results of REfCo4Sb12 and REfFe4Sb12 (RE = Yb, Ba, and Ca) alloys. To further test the validity of our model, we calculate the lattice thermal conductivity of nanostructured or multi-filled skutterudites. The calculation results are also in good agreement with experiment, increasing our confidence in the developed anharmonicity model.
On thermonuclear ignition criterion at the National Ignition Facility
Authors: Cheng Baolian , Kwan Thomas J. T. , Wang Yi-Ming , Batha Steven H.
Published: October 2014

Sustained thermonuclear fusion at the National Ignition Facility remains elusive. Although recent experiments approached or exceeded the anticipated ignition thresholds, the nuclear performance of the laser-driven capsules was well below predictions in terms of energy and neutron production. Such discrepancies between expectations and reality motivate a reassessment of the physics of ignition. We have developed a predictive analytical model from fundamental physics principles. Based on the model, we obtained a general thermonuclear ignition criterion in terms of the areal density and temperature of the hot fuel. This newly derived ignition threshold and its alternative forms explicitly show the minimum requirements of the hot fuel pressure, mass, areal density, and burn fraction for achieving ignition. Comparison of our criterion with existing theories, simulations, and the experimental data shows that our ignition threshold is more stringent than those in the existing literature and that our results are consistent with the experiments.
Interface magnetism of Co2FeGe Heusler alloy layers and magnetoresistance of Co2FeGe/MgO/Fe magnetic tunnel junctions
Authors: Tanaka M. A. , Maezaki D. , Ishii T. , Okubo A. , Hiramatsu R. , Ono T. , Mibu K.
Published: October 2014

The interface magnetism between Co2FeGe Heusler alloy layers and MgO layers was investigated using 57Fe Mössbauer spectroscopy. Interface-sensitive samples, where the 57Fe isotope was used only for the interfacial atomic layer of the Co2FeGe layer on the MgO layer, were prepared using atomically controlled alternate deposition. The 57Fe Mössbauer spectra of the interface-sensitive samples at room temperature were found similar to those of the bulk-sensitive Co2FeGe films in which the 57Fe isotope was distributed throughout the films. On the other hand, the tunnel magnetoresistance effect of magnetic tunnel junctions with Co2FeGe layers as the ferromagnetic electrodes showed strong reduction at room temperature. These results indicate that the strong temperature dependence of the tunneling magnetoresistance of magnetic tunnel junctions using Heusler alloy electrodes cannot be attributed simply to the reduction of the magnetization at the interfaces between the Heusler alloy and insulator layers.
Irreversibility fields and critical current densities in strongly pinned YBa2Cu3O7-x films with BaSnO3 nanorods: The influence of segmented BaSnO3 nanorods
Authors: Matsumoto Kaname , Tanaka Isamu , Horide Tomoya , Mele Paolo , Yoshida Yutaka , Awaji Satoshi
Published: October 2014

We report irreversibility fields Birr and critical current densities Jc in YBa2Cu3O7-x thin films containing segmented BaSnO3 nanorods. Birr and Jc are systematically changed by selection of nanorod length and its spacing, and the variations are explained by the “harmonic oscillator” approach based on the Bose glass state. Analysis of pinning energies and Jc indicates that segmented nanorods behave as single columnar pin for B || c, in contrast, as nanoparticle pins for B || ab. The present results may help to further investigate anisotropy tuning of pinning structures.
Renormalization plasma shielding effects on scattering entanglement fidelity in dense plasmas
Authors: Lee Gyeong Won , Shim Jaewon , Jung Young-Dae
Published: October 2014

The influence of renormalization plasma screening on the entanglement fidelity for the elastic electron-atom scattering is investigated in partially ionized dense hydrogen plasmas. The partial wave analysis and effective interaction potential are employed to obtain the scattering entanglement fidelity in dense hydrogen plasmas as functions of the collision energy, the Debye length, and the renormalization parameter. It is found that the renormalization plasma shielding enhances the scattering entanglement fidelity. Hence, we show that the transmission of the quantum information can be increased about 10% due to the renormalization shielding effect in dense hydrogen plasmas. It is also found that the renormalization shielding effect on the entanglement fidelity for the electron-atom collision increases with an increase of the collision energy. In addition, the renormalization shielding function increases with increasing collision energy and saturates to the unity with an increase of the Debye length.
Qualifying composition dependent p and n self-doping in CH3NH3PbI3
Authors: Wang Qi , Shao Yuchuan , Xie Haipeng , Lyu Lu , Liu Xiaoliang , Gao Yongli , Huang Jinsong
Published: October 2014

We report the observation of self-doping in perovskite. CH3NH3PbI3 was found to be either n- or p-doped by changing the ratio of methylammonium halide (MAI) and lead iodine (PbI2) which are the two precursors for perovskite formation. MAI-rich and PbI2-rich perovskite films are p and n self-doped, respectively. Thermal annealing can convert the p-type perovskite to n-type by removing MAI. The carrier concentration varied as much as six orders of magnitude. A clear correlation between doping level and device performance was also observed.
Structural consequences of hydrogen intercalation of epitaxial graphene on SiC(0001)
Authors: Emery Jonathan D. , Wheeler Virginia D. , Johns James E. , McBriarty Martin E. , Detlefs Blanka , Hersam Mark C. , Kurt Gaskill D. , Bedzyk Michael J.
Published: October 2014

The intercalation of various atomic species, such as hydrogen, to the interface between epitaxial graphene (EG) and its SiC substrate is known to significantly influence the electronic properties of the graphene overlayers. Here, we use high-resolution X-ray reflectivity to investigate the structural consequences of the hydrogen intercalation process used in the formation of quasi-free-standing (QFS) EG/SiC(0001). We confirm that the interfacial layer is converted to a layer structurally indistinguishable from that of the overlying graphene layers. This newly formed graphene layer becomes decoupled from the SiC substrate and, along with the other graphene layers within the film, is vertically displaced by ∼2.1 Å. The number of total carbon layers is conserved during the process, and we observe no other structural changes such as interlayer intercalation or expansion of the graphene d-spacing. These results clarify the under-determined structure of hydrogen intercalated QFS-EG/SiC(0001) and provide a precise model to inform further fundamental and practical understanding of the system.
Design of 4-electrode optical device for application of vector electric fields to self-assembled quantum dot complexes
Authors: Zhou Xinran , Doty Matthew
Published: October 2014

Self-assembled InAs quantum dots (QDs) are of great interest as components of optoelectronic devices that can operate at the quantum limit. The charge configuration, interdot coupling, and symmetry of complexes containing multiple QDs can all be tuned with applied electric fields, but the magnitude and angle of the electric field required to control each of these parameters depend on the orientation of the QD complex. We present a 4-electrode device compatible with optical excitation and emission that allows application of electric fields with arbitrary magnitudes and angles relative to isolated QD complexes. We demonstrate the electric field tunability of this device with numerical simulations.
Nanoscale electro-mechanical dynamics of nano-crystalline platinum thin films: An in situ electrical nanoindentation study
Authors: Nili Hussein , Walia Sumeet , Bhaskaran Madhu , Sriram Sharath
Published: October 2014

Here, we present a detailed methodology for the study of nano-electromechanical properties of thin films through in situ electrical nanoindentation. The nanomechanical properties of nano-crystalline platinum thin films have been accurately evaluated via nullifying multiple phenomena and artefacts that can introduce errors in interpreting nanoindentation experimental data. To gain quantified insights from in situ electrical measurements, an empirical equation is introduced to model the resistance imposed by the conductive probe at the nanoscale contact as a function indentation depth and load. Using the empirical model, nanoscale electrical properties of nano-crystalline platinum films are quantitatively evaluated. It is observed that the resistivity of the platinum increases subject to high contact pressure, which is also associated with substantial structural deformations around the nano-contact area.
Suppression of the asymmetric competition mode in the relativistic Ku-band coaxial transit-time oscillator
Authors: Ling Junpu , He Juntao , Zhang Jiande , Jiang Tao , Wang Lei
Published: October 2014

A relativistic Ku-band coaxial transit-time oscillator has been proposed in our previous work. In the experiments, we find that the asymmetric competition mode in the device limits the microwave power with the increase of the input electric power. For solving such a problem, the methods for analysis and suppression of the asymmetric competition mode in the device are investigated theoretically and experimentally. It is shown that the structure and the material of the collector, the concentricity, and the electron emission uniformity play an important part in the suppression of the asymmetric competition mode in the relativistic Ku-band transit-time oscillator. In the subsequent experiments, the asymmetric mode was suppressed effectively. At a low guiding magnetic field of 0.7 T, a microwave pulse with power of 1 GW, frequency of 14.3 GHz close to the simulation one, and efficiency of 20% was generated.
Optical nonlinearities and carrier dynamics in Fe doped GaN single crystal
Authors: Fang Yu , Yang Junyi , Li Zhongguo , Yang Yong , Wu Xingzhi , Song Yinglin , Zhou Feng
Published: October 2014

Optical nonlinearities and transient dynamics of Fe doped GaN (GaN:Fe) were studied by Z-scan and pump-probe with phase object techniques under picosecond and nanosecond at 532 nm. From the pump-probe results, an additional decay pathway subsequent to two photon excitation was observed due to the carrier trapping of Fe3+/Fe2+ deep acceptors. The trapping state in the band gap results in a pronounced modulation to nonlinear responses of GaN:Fe compared to that of undoped GaN. With an effective three-level model as well as carrier trapping effect we described the photo-physical dynamics in GaN:Fe unambiguously.
Dark soliton based frequency dependent dielectric constant of ferroelectric materials
Authors: Giri Pradipta , Mandal M. K.
Published: October 2014

A model of one dimensional array of the slab domain of a ferroelectric crystal and its polarization with time and space is explained by nonlinear Klein Gorden (KG) equation. The present article has been shown the slower moving dark soliton and faster moving bright soliton both move in nonlinear system with dispersive frequency that has significant as characterized frequency of ferroelectric medium. It is also shown that the dark soliton has an important role to control the magnitude of dielectric constant of the medium. The frequency dependent dielectric constant is evaluated from the nonlinear Klein Gorden (NLKG) equation using characterized frequency and it matches with the experimental results.
Probabilistic Explanation
Authors: Strevens Michael
Published: October 2014

Explanations are often probabilistic or statistical in nature. This chapter explores the contexts in which such explanations occur and provides accounts of their structure. The inductive-statistical model and models invoking intrinsic probabilistic causation are described and criticized, and the uses of statistical explanation in science are discussed. The subsumption model of statistical explanation and some of its demands and results are explored along with proposals that causation is essential even to statistical explanation and that statistical explanations are founded on irreducible stochastic dispositions. Indeterminism is outlined, and the chapter suggests that a notion of “robustness” is a requirement of a probabilistic explanation.
“The Most Worthy of Women is a Mistress of Magic”: Women as Witches and Ritual Practitioners in 1 Enoch and Rabbinic Sources
Authors: Lesses Rebecca
Published: October 2014

Biblical, post-biblical, and rabbinic literature portray women as sorcerers, but as The chapter demonstrates, the traditions vary substantially depending on the rhetorical and ideological context of the texts in which they appear. The bible, for example, presents an ambivalent position on the sex of magic practitioners in pre-Exilic Israel. The chapter traces this ambivalence through second temple writings, such as 1 Enoch, and rabbinic literature to show that while some texts do seem to identify women (or nations personified as women) with sorcery and forbidden knowledge, other texts do not, concluding that the relationship between women and sorcery as presented in early Jewish sources resists reduction to a single charge of misogyny.
Equilibrium Statistical Mechanics of Long-Range Interactions
Authors: Campa A. , Dauxois T. , Fanelli D. , Ruffo S.
Published: October 2014

This chapter deals with the peculiarities that are present in the statistical mechanics treatment and in the equilibrium properties of system with long-range interactions. In dimension d they are characterized at large distance r by a decay slower than 1/rd. The important concepts of additivity and extensivity are analysed. It is shown that long-range systems are intrinsically nonadditive: the interaction energy between macroscopic subsystems is not negligible with respect to the total energy of the system. This can often give rise to ensemble inequivalence. In particular, also with the help of a simple model, the possibility to have convex regions in the entropy is demonstrated. These regions can cause a negative specific heat in the microcanonical ensemble, while in the canonical ensemble this quantity is always positive. A negative magnetic susceptibility is possible, as well, in the microcanonical ensemble.
The Large Deviations Method and Its Applications
Authors: Campa A. , Dauxois T. , Fanelli D. , Ruffo S.
Published: October 2014

This chapter is devoted to the study of a very useful mathematical tool for the computation of the entropy in long-range systems. The method is based on large deviation theory, and it is very well suited for purely mean-field systems, in which the interaction does not decay at all with the distance. However, it can be applied also to the other long-range systems. The three steps of the method are described: the expression of the energy in terms of global variables, the mean fields; the computation of the entropy of the macrostates, defined by given values of the mean fields; the computation of the entropy, maximizing on the macrostates. Finally, the method is illustrated by applying it to two simple models.
Solutions of Mean Field Models
Authors: Campa A. , Dauxois T. , Fanelli D. , Ruffo S.
Published: October 2014

In this chapter the theory and the tools described in the previous two chapters are applied to several simple mean-field models, computing both the microcanonical and the canonical partition functions. It is shown that in the first model, the Hamiltonian Mean Field model, ensembles are equivalent, while in the others, the generalized XY model, the phi-4 model and the Self-Gravitating Ring model, ensembles are nonequivalent, with the occurrence of negative specific heat or negative susceptibility in the microcanonical ensemble. A feature that can appear in long-range systems is presented, namely the occurrence of ergodicity breaking. Mentioned in chapter 2 as a consequence of the possibility to have not connected regions in the thermodynamic parameter space, it is here explicitly shown in the XY model. Ergodicity breaking clearly manifests itself in the dynamical behaviour.
Beyond Mean-Field Models
Authors: Campa A. , Dauxois T. , Fanelli D. , Ruffo S.
Published: October 2014

This chapter aims at showing that the features occurring in mean-field models, described in the previous chapters, can be found also in the other long-range systems. The first four sections are dedicated to generalizations of the models of chapter 4, in which either the mean-field interaction is augmented with a nearest neighbour interaction, or it is replaced by a slowly decaying interaction. It is shown that the long-range characteristics of the associated mean-field models are preserved, and in addition ensemble inequivalence, microcanonical negative specific heat and ergodicity breaking are induced in some cases. The final section introduces the dipolar interaction, a marginal long-range system. Dipolar systems are treated in details in chapter 15, and in this chapter few relevant properties are presented, focussing in particular on elongated ferromagnets and on ergodicity breaking.
Kinetic Theory of Long-Range Systems: Klimontovich, Vlasov and Lenard–Balescu Equations
Authors: Campa A. , Dauxois T. , Fanelli D. , Ruffo S.
Published: October 2014

This chapter describes the derivation of kinetic equations for long-range systems. This is done on the basis of the Klimontovich equation, following an approach which is alternative but equivalent to the BBGKY hierarchy. After the derivation of the Klimontovich equation, that mathematically is equivalent to the full equations of motion, the Vlasov and the Lenard-Balescu equations are obtained. The former approximates the interaction in the system with a mean-field force, and for this it is considered a collisionless approximation; the latter takes into account the collisional corrections to the Vlasov equation. In the last section, with the background of the general theory presented in chapter 2 and in this chapter, there is a description of the physical meaning of the Kac’s prescription, often used as a convenient tool for the study of long-range systems.
Dipolar Systems
Authors: Campa A. , Dauxois T. , Fanelli D. , Ruffo S.
Published: October 2014

This chapter is devoted to studying systems with magnetic dipolar interactions. After a general introduction, the origin of the so called demagnetized field arising in the interior of magnetized bodies, is discussed. Then, the existence of a thermodynamic limit for systems of dipoles coupled via a dipole-dipole interaction, is shown. Importantly, the free energy of the system is independent on the sample shape. The physical consequences of this result are thoroughly analyzed. Finally, recent experimental studies aimed at investigating both equilibrium and dynamical properties of dipolar systems are reviewed and discussed.
The cost-effectiveness of radiofrequency catheter ablation as
first-line treatment for paroxysmal atrial fibrillation: results from a
MANTRA-PAF substudy
Authors: Aronsson Mattias , Walfridsson Håkan , Janzon Magnus , Walfridsson Ulla , Nielsen Jens Cosedis , Hansen Peter Steen , Johannessen Arne , Raatikainen Pekka , Hindricks Gerhard , Kongstad Ole , Pehrson Steen , Englund Anders , Hartikainen Juha , Mortensen Leif Spange , Levin Lars-Åke
Published: October 2014

Aim

The aim of this prospective substudy was to estimate the cost-effectiveness of treating paroxysmal atrial fibrillation (AF) with radiofrequency catheter ablation (RFA) compared with antiarrhythmic drugs (AADs) as first-line treatment.

Methods and results

A decision-analytic Markov model, based on MANTRA-PAF (Medical Antiarrhythmic Treatment or Radiofrequency Ablation in Paroxysmal Atrial Fibrillation) study data, was developed to study long-term effects and costs of RFA compared with AADs as first-line treatment. Positive clinical effects were found in the overall population, a gain of an average 0.06 quality-adjusted life years (QALYs) to an incremental cost of €3033, resulting in an incremental cost-effectiveness ratio of €50 570/QALY. However, the result of the subgroup analyses showed that RFA was less costly and more effective in younger patients. This implied an incremental cost-effectiveness ratio of €3434/QALY in ≤50-year-old patients respectively €108 937/QALY in >50-year-old patients.

Conclusion

Radiofrequency catheter ablation as first-line treatment is a cost-effective strategy for younger patients with paroxysmal AF. However, the cost-effectiveness of using RFA as first-line therapy in older patients is uncertain, and in most of these AADs should be attempted before RFA (MANTRA-PAF ClinicalTrials.gov number; NCT00133211).
Chromosome conformation maps in fission yeast reveal cell cycle dependent sub nuclear structure
Authors: Grand Ralph S. , Pichugina Tatyana , Gehlen Lutz R. , Jones M. Beatrix , Tsai Peter , Allison Jane R. , Martienssen Robert , O'Sullivan Justin M.
Published: October 2014

Successful progression through the cell cycle requires spatial and temporal regulation of gene transcript levels and the number, positions and condensation levels of chromosomes. Here we present a high resolution survey of genome interactions in Schizosaccharomyces pombe using synchronized cells to investigate cell cycle dependent changes in genome organization and transcription. Cell cycle dependent interactions were captured between and within S. pombe chromosomes. Known features of genome organization (e.g. the clustering of telomeres and retrotransposon long terminal repeats (LTRs)) were observed throughout the cell cycle. There were clear correlations between transcript levels and chromosomal interactions between genes, consistent with a role for interactions in transcriptional regulation at specific stages of the cell cycle. In silico reconstructions of the chromosome organization within the S. pombe nuclei were made by polymer modeling. These models suggest that groups of genes with high and low, or differentially regulated transcript levels have preferred positions within the S. pombe nucleus. We conclude that the S. pombe nucleus is spatially divided into functional sub-nuclear domains that correlate with gene activity. The observation that chromosomal interactions are maintained even when chromosomes are fully condensed in M phase implicates genome organization in epigenetic inheritance and bookmarking.
A kinetic mechanism for cell sorting based on local variations in cell motility
Authors: Strandkvist Charlotte , Juul Jeppe , Baum Buzz , Kabla Alexandre J. , Duke Tom
Published: October 2014

Our current understanding of cell sorting relies on physical difference, either in the interfacial properties or motile force, between cell types. But is such asymmetry a prerequisite for cell sorting? We test this using a minimal model in which the two cell populations are identical with respect to their physical properties and differences in motility arise solely from how cells interact with their surroundings. The model resembles the Schelling model used in social sciences to study segregation phenomena at the scale of societies. Our results demonstrate that segregation can emerge solely from cell motility being a dynamic property that changes in response to the local environment of the cell, but that additional mechanisms are necessary to reproduce the envelopment behaviour observedin vitro. The time course of segregation follows a power law, in agreement with the scaling reported from experiment and in other models of motility-driven segregation.
Effects of molecular noise on bistable protein distributions in rod-shaped bacteria
Authors: Wettmann L. , Bonny M. , Kruse K.
Published: October 2014

The distributions of many proteins in rod-shaped bacteria are far from homogeneous. Often they accumulate at the cell poles or in the cell centre. At the same time, the copy number of proteins in a single cell is relatively small making the patterns noisy. To explore limits to protein patterns due to molecular noise, we studied a generic mechanism for spontaneous polar protein assemblies in rod-shaped bacteria, which are based on cooperative binding of proteins to the cytoplasmic membrane. For mono-polar assemblies, we find that the switching time between the two poles increases exponentially with the cell length and with the protein number. This feature could be beneficial to organelle maintenance in ageing bacteria.
Bayesian analyses of Yemeni mitochondrial genomes suggest multiple migration events with Africa and Western Eurasia
Authors: Vyas Deven N. , Kitchen Andrew , Miró-Herrans Aida T. , Pearson Laurel N. , Al-Meeri Ali , Mulligan Connie J.
Published: October 2014

Anatomically modern humans (AMHs) left Africa ˜60,000 years ago, marking the first of multiple dispersal events by AMH between Africa and the Arabian Peninsula. The southern dispersal route (SDR) out of Africa (OOA) posits that early AMHs crossed the Bab el-Mandeb strait from the Horn of Africa into what is now Yemen and followed the coast of the Indian Ocean into eastern Eurasia. If AMHs followed the SDR and left modern descendantsin situ, Yemeni populations should retain old autochthonous mitogenome lineages. Alternatively, if AMHs did not follow the SDR or did not leave modern descendants in the region, only young autochthonous lineages will remain as evidence of more recent dispersals. We sequenced 113 whole mitogenomes from multiple Yemeni regions with a focus on haplogroups M, N, and L3(xM,N) as they are considered markers of the initial OOA migrations. We performed Bayesian evolutionary analyses to generate time-measured phylogenies calibrated by Neanderthal and Denisovan mitogenome sequences in order to determine the age of Yemeni-specific clades in our dataset. Our results indicate that the M1, N1, and L3(xM,N) sequences in Yemen are the product of recent migration from Africa and western Eurasia. Although these data suggest that modern Yemeni mitogenomes are not markers of the original OOA migrants, we hypothesize that recent population dynamics may obscure any genetic signature of an ancient SDR migration.
The MaizeDWARF1Encodes a Gibberellin 3-Oxidase and Is Dual Localized to the Nucleus and Cytosol
Authors: Chen Yi , Hou Mingming , Liu Lijuan , Wu Shan , Shen Yun , Ishiyama Kanako , Kobayashi Masatomo , McCarty Donald R. , Tan Bao-Cai
Published: October 2014

The maize (Zea mays) gibberellin (GA)-deficient mutant dwarf1 (d1) displays dwarfism and andromonoecy (i.e. forming anthers in the female flower). Previous characterization indicated that the d1 mutation blocked three steps in GA biosynthesis; however, the locus has not been isolated and characterized. Here, we report that D1 encodes a GA 3-oxidase catalyzing the final step of bioactive GA synthesis. Recombinant D1 is capable of converting GA20 to GA1, GA20 to GA3, GA5 to GA3, and GA9 to GA4 in vitro. These reactions are widely believed to take place in the cytosol. However, both in vivo GFP fusion analysis and western-blot analysis of organelle fractions using a D1-specific antibody revealed that the D1 protein is dual localized in the nucleus and cytosol. Furthermore, the upstream gibberellin 20-oxidase1 (ZmGA20ox1) protein was found dual localized in the nucleus and cytosol as well. These results indicate that bioactive GA can be synthesized in the cytosol and the nucleus, two compartments where GA receptor Gibberellin-insensitive dwarf protein1 exists. Furthermore, the D1 protein was found to be specifically expressed in the stamen primordia in the female floret, suggesting that the suppression of stamen development is mediated by locally synthesized GAs.
Crystal structure of 1,1′-bis[1,7-dicarba-closo-dodecaborane(11)]
Authors: Elrick Lisa , Rosair Georgina M. , Welch Alan J.
Published: October 2014

In the title compound, C4H22B20, the two {1,7-closo-C2B10H11} cages are linked across a centre of inversion, with C—C = 1.5401 (16) Å. The position of the second non-linking cage C atom was established unambiguously by geometric and crystallographic methods and there is no evidence of C/B disorder.
Crystal structure of 1-[2,4-bis(4-methoxyphenyl)-3-azabicyclo[3.3.1]nonan-3-yl]ethanone
Authors: Shreevidhyaa Suressh V. , Sathya S. , Akila A. , Ponnuswamy S. , Usha G.
Published: October 2014

In the title compound, C24H29NO3, the azabicycle contains two six-membered rings,viz.a cyclohexane ring and a piperidine ring. The first adopts a chair conformation and the second a half-chair conformation. The dihedral angle between their mean planes is 86.21 (13)°, indicating that they are almost perpendicular to one another. The dihedral angle between the planes of the 4-methoxyphenyl rings is 17.51 (13)°, and they make dihedral angles of 81.9 (3) and 81.3 (3)° with the ethan-1-one group. In the crystal, molecules are linked by C—H...π interactions forming chains along [10-1].
Crystal structures of (RS)-N-[(1R,2S)-2-benzyloxy-1-(2,6-dimethylphenyl)propyl]-2-methylpropane-2-sulfinamide and (RS)-N-[(1S,2R)-2-benzyloxy-1-(2,4,6-trimethylphenyl)propyl]-2-methylpropane-2-sulfinamide: two related protected 1,2-amino alcohols
Authors: Carbone Matthew R. , Centola Garrick A. , Haas Adam , McClelland Kevin P. , Moskowitz Michael D. , Verderame Angelo M. , Olezeski Mikael S. , Papa Louis J. , Dorn Stephanie C. M. , Brennessel William W. , Weix Daniel J.
Published: October 2014

The title compounds, C22H31NO2S, (1), and C23H33NO2S, (2), are related protected 1,2-amino alcohols. They differ in the substituents on the benzene ring,viz.2,6-dimethylphenyl in (1) and 2,4,6-trimethylphenyl in (2). The plane of the phenyl ring is inclined to that of the benzene ring by 28.52 (7)° in (1) and by 44.65 (19)° in (2). In the crystal of (1), N—H...O=S and C—H...O=S hydrogen bonds link molecules, forming chains along [100], while in (2), similar hydrogen bonds link molecules into chains along [010]. The absolute structures of both compounds were determined by resonance scattering.
Crystal structure of potassium (1R)-D-ribit-1-ylsulfonate
Authors: Haines Alan H. , Hughes David L.
Published: October 2014

The title compound, K+·C5H11O8S−[systematic name: potassium (1R,2R,3R,4R)-1,2,3,4,5-pentahydroxypentane-1-sulfonate], formed by reaction of D-ribose with potassium hydrogen sulfite in water, crystallizes as colourless plates. The anion has an open-chain structure in which the S atom and the C atoms of the sugar chain, excepting that of the hydroxymethyl group, form an essentially all-transchain; the C atom of the hydroxymethyl group lies in agaucherelationship with the three contiguous C atoms. Through complex cation coordination (through seven oxygen atoms of six different anions) and intermolecular O—H...O hydrogen bonding, a three-dimensional bonding network exists in the crystal structure.
Crystal structure of zwitterionic 4-(ammoniomethyl)benzoate: a simple molecule giving rise to a complex supramolecular structure
Authors: Atria Ana María , Garland Maria Teresa , Baggio Ricardo
Published: October 2014

The asymmetric unit of the title compound, C8H9NO2·H2O consists of an isolated 4-(ammoniomethyl)benzoate zwitterion derived from 4-aminomethylbenzoic acid through the migration of the acidic proton, together with a water molecule of crystallization that is disordered over three sites with occupancy ratios (0.50:0.35:0.15). In the crystal structure, N—H...O hydrogen bonds together with π–π stacking of the benzene rings [centroid–centroid distance = 3.8602 (18) Å] result in a strongly linked, compact three-dimensional structure.
Crystal structure of (5-methylimidazo[1,2-a]pyridin-2-yl)methanol
Authors: Elaatiaoui Abdelmalik , Koudad Mohammed , Saddik Rafik , Benchat Noureddine , El Ammari Lahcen
Published: October 2014

In the title compound, C9H10N2O, the imidazo[1,2-a]pyridine moiety is approximately planar (r.m.s. deviation = 0.024 Å). The methanol group is nearly perpendicular to its mean plane as indicated by the C—C—C—O and N—C—C—O torsion angles of 80.04 (16) and −96.30 (17)°, respectively. In the crystal, molecules are linked by O—H...N hydrogen bonds, forming inversion dimers with anR22(10) ring motif. The dimers are likedviaC—H...O hydrogen bonds, enclosingR22(10) ring motifs and forming ribbons along [201]. The ribbons are linkedviaa number of π–π interactions [centroid–centroid distances vary from 3.4819 (8) to 3.7212 (8) Å], forming a three-dimensional structure.
Crystal structure of ethyl 6-(chloromethyl)-4-(4-chlorophenyl)-2-oxo-1,2,3,4-tetrahydropyrimidine-5-carboxylate
Authors: Bharanidharan S. , Saleem H. , Gunasekaran B. , Padusha M. Syed Ali , Suresh M.
Published: October 2014

In the title compound, C14H14Cl2N2O3, the chlorophenyl ring makes a dihedral angle of 87.08 (9)° with the tetrahydropyrimidine ring. There is a short intramolecular C—H...O contact present. In the crystal, molecules are linkedviapairs of N—H...O hydrogen bonds, forming inversion dimers with anR22(8) ring motif. The dimers are linkedviaa second pair of N—H...O hydrogen bonds, this time enclosing anR44(20) ring motif, forming ribbons along [100]. The ribbons are linkedviaC—H...O hydrogen bonds, forming sheets lying parallel to (001). The terminal ethyl group is disordered over two positions with an occupancy ratio of 0.654 (17):0.346 (17).
Crystal structure of 1,3-bis(2,6-diisopropylphenyl)-4,5-dimethyl-1H-imidazol-3-ium bromide dichloromethane disolvate
Authors: Berger Matthias , Auner Norbert , Bolte Michael
Published: October 2014

The title solvated salt, C29H41N2+·Br−·2CH2Cl2was obtained from the reaction of the Arduengo-type carbene 1,3-bis(2,6-diisopropylphenyl)-1,3-dihydro-4,5-dimethyl-2H-imidazol-2-ylidene with Si2Br6in dichloromethane. The complete cation is generated by a crystallographic mirror plane and the dihedral angle between the five-membered ring and the benzene ring is 89.8 (6)°; the dihedral angle between the benzene rings is 40.7 (2)°. The anion also lies on the mirror plane and both dichloromethane molecules are disordered across the mirror plane over two equally occupied orientations. In the crystal, the cations are linked to the anionsviaC—H...Br hydrogen bonds.
Crystal structure of 3-({[(morpholin-4-yl)carbonothioyl]sulfanyl}acetyl)phenyl benzoate
Authors: Ambekar Sachin P. , Mahesh Kumar K. , Shirahatti Arun Kumar M. , Kotresh O. , Anil Kumar G. N.
Published: October 2014

In the title compound, C20H19NO4S2, the morpholine ring adopts the expected chair conformation. The central phenyl ring makes dihedral angles of 67.97 (4) and 7.74 (3)°, respectively, with the benzoate phenyl ring and the morpholine mean plane. In the crystal, molecules are linked by C—H...O hydrogen bonds, forming zigzag chains along theb-axis direction. C—H...π interactions link centrosymmetrically related molecules, reinforcing the three-dimensional structure.
Crystallization, room-temperature X-ray diffraction and preliminary analysis of Kaposi's sarcoma herpesvirus LANA bound to DNA
Authors: Hellert Jan , Krausze Joern , Schulz Thomas F. , Lührs Thorsten
Published: October 2014

The latency-associated nuclear antigen (LANA) is the latent origin-binding protein and chromatin anchor of the Kaposi's sarcoma herpesvirus (KSHV/HHV-8) genome. Its C-terminal domain (CTD) binds sequence-specifically to the viral origin of replication, whereas the N-terminal domain links it to nucleosomes of cellular chromatin for long-term persistence in dividing host cells. Here, the crystallization and X-ray data acquisition of a mutant LANA CTD in complex with its wild-type target DNA LBS1 is described. This report describes the rational protein engineering for successful co-crystallization with DNA and X-ray diffraction data collection at room temperature on the high-brilliance third-generation synchrotron PETRA III at DESY, Germany.
Smart specialisation in the tangled web of European inter-regional trade
Authors: Gianelle Carlo , Goenaga Xabier , González Vázquez Ignacio , Thissen Mark
Published: October 2014

Purpose

– The purpose of this paper is to present a new methodology to assess the outward connectivity among regional economies in the European Union (EU) and derives policy lessons for the design of regional innovation and competitiveness-enhancing strategic frameworks, with particular reference to research and innovation strategies for smart specialisation (RIS3).

Design/methodology/approach

– The authors study the network of inter-regional trade flows in the EU25 in the year 2007. Trade data are taken from the PBL Netherlands Environmental Assessment Agency database and mapped onto weighted directed networks in which the nodes represent regions and the links are flows of goods. The authors measure several structural characteristics of the networks, both global properties and centrality indicators describing the position of individual regions within the system.

Findings

– European regions appear to be mostly integrated in the European single market. Strengths and weaknesses of individual regions are discussed based on rankings obtained from network centrality indicators. Specific policy implications in the context of RIS3 are derived in the case of the Spanish region of Andalusia.

Practical implications

– The authors show the potential of the methodology for providing a new family of indicators of the external connectivity of regional economies that can be used by regions wishing to develop their own RIS3 for 2014-2020, as required by the EU in the context of the new cohesion policy framework.

Originality/value

– The characteristics of a EU-wide inter-regional network of trade flows are obtained and thoroughly discussed for the first time. A unique and original instrument suitable for inter-regional comparison is developed and tested.
How has the French context shaped the organization of the Airbus Group?
Authors: Barmeyer Christoph , Mayrhofer Ulrike
Published: October 2014

Purpose

– The purpose of this paper is to examine whether characteristics of French organizations can be found in the Airbus Group, ancient European Aeronautic Defence and Space Company (EADS) Group, and how these characteristics have evolved over time in comparison to German ones.

Design/methodology/approach

– This article presents an in-depth case study by using a contextual approach, considering influential factors which are likely to influence the evolution of organizations.

Findings

– The analysis shows that the Airbus Group reflects characteristics of French organizations: the importance of strategy, the principle of honour, centralization of decision and power, the role of the state in the capital and its influence via professional networks of its elite coming from the Grandes Ecoles. These findings confirm a relative continuity of national peculiarities over time. The recent evolution of the company also highlights the German influence, notably in terms of shares and management positions.

Research limitations/implications

– The case study demonstrates that the Airbus Group has become a multinational company where contextual elements and organizational structures regulate intercultural relationships of interests, influence and power.

Originality/value

– Five contextual factors are proposed, which allow to understand and structure the peculiarities of French organizations, in comparison to German ones as well as power distribution within the Airbus Group.