bluuebunny/crossref_metadata_2025 huggingface dataset:
Timing estimation algorithm for OFDM‐based wireless systems
Authors: Suresh Madhan Nanchan , Ananthi Govindasamy , Thiruvengadam Sundarrajan Jayaraman , Abhaikumar Varadhan
Published: October 2016

Orthogonal frequency division multiplexing (OFDM) is a promising technique for wireless system due to its high spectral efficiency and its capability to counteract frequency selective fading channels. However, OFDM system is highly vulnerable to timing offset. This study proposes a novel timing estimation algorithm for downlink OFDM systems. A novel training sequence structure using Chu sequence is proposed. A new property of the inverse discrete Fourier transform of Chu sequence is derived. This property is used to obtain channel impulse response to estimate start of the OFDM symbol. The mean square error and timing detection performance of the proposed algorithm are shown to be better than the existing methods.
Investigation of the behaviour of electronic resistive switching memory based on MoSe2-doped ultralong Se microwires
Authors: Zhou Guangdong , Sun Bai , Yao Yanqing , Zhang Huihui , Zhou Ankun , Alameh Kamal , Ding Baofu , Song Qunliang
Published: October 2016

MoSe2-doped ultralong Se microwires of length/diameter ratio in the order of ∼240 are synthesized by hydrothermal method. An electronic resistive switching memory (ERSM) device using a single MoSe2-doped ultralong Se microwire is attained. The ERSM exhibits stable resistance ratio of ∼102 for 5000 s, highly stable performance during 500 stressing cycles, and excellent immunity to the frequency of the driving voltage. By investigating the dynamic processes of trap filling, de-trapping, and free-charge migration, trap-controlled space-charge-limited current mechanism is found to dominate the observed ERSM behaviour.
Peculiarities of thermal expansion of quasi-two-dimensional organic conductor κ-(BEDT–TTF)2Cu[N(CN)2]Cl
Authors: Dolbin A. V. , Khlistuck M. V. , Eselson V. B. , Gavrilko V. G. , Vinnikov N. A. , Basnukaeva R. M. , Danchuk V. V. , Konstantinov V. A. , Nakazawa Y.
Published: October 2016

Linear coefficient of thermal expansion α(T) of single crystal (BEDT–TTF)2Cu[N(CN)2]C1 was studied along the crystal layers using the method of precise capacitive dilatometry in the temperature range 2–285 K. It is positive in this direction over the entire temperature range. Anomalies of thermal expansion were observed at 29–30 K and 74–80 K. The anomaly near 30 K is, apparently, due to the transition between the paramagnetic phase and the antiferromagnetic insulator state. Peak of α(T) at 78 K corresponds to a phase transition related to orientational disordering of ethylene groups in dimers of BEDT–TTF. A broad maximum of α(T) in the temperature range 40–70 K, is apparently explained by fluctuations of charge within the dimers, and by spin fluctuations, which first increase with increasing temperature, and then decrease in process of thermal disordering of dimers.
Hybrid-impurity resonance in a quantum wire placed in a magnetic field
Authors: Karpunin V. V. , Margulis V. A.
Published: October 2016

An analytical expression for the absorption coefficient of electromagnetic radiation in a quantum wire is obtained. We consider the case of a field lying in the plane perpendicular to the wire axis. The calculation is performed using second-order perturbation theory with consideration of electron scattering by ionized impurities. We demonstrate the resonant character of the absorption and find the position of resonance frequencies in the dependence on the magnitude and direction of the magnetic field.
Point-contact function of the electron–phonon interaction in zirconium
Authors: Bobrov N. L. , Rybaltchenko L. F. , Fisun V. V. , Khotkevich A. V.
Published: October 2016

Experimental study of the electron–phonon interaction (EPI) spectra of zirconium was carried out using Yanson's point-contact (PC) spectroscopy. The EPI spectral function and constant were determined. Both homocontacts (Zr–Zr) and heterocontacts (Zr–Cu, Zr–Ag, and Zr–Au) were studied. No contribution by copper, silver or gold to the heterocontact spectra was detected. The positions of five phonon features of the EPI function were observed at energies 5–6, 9–11, 13–15, 18–20, and 27–29 meV. The observed diversity of the PC spectra was attributed to the anisotropy of Zr.
Density-fitted open-shell symmetry-adapted perturbation theory and application to π-stacking in benzene dimer cation and ionized DNA base pair steps
Authors: Gonthier Jérôme F. , Sherrill C. David
Published: October 2016

Symmetry-Adapted Perturbation Theory (SAPT) is one of the most popular approaches to energy component analysis of non-covalent interactions between closed-shell systems, yielding both accurate interaction energies and meaningful interaction energy components. In recent years, the full open-shell equations for SAPT up to second-order in the intermolecular interaction and zeroth-order in the intramolecular correlation (SAPT0) were published [P. S. Zuchowski et al., J. Chem. Phys. 129, 084101 (2008); M. Hapka et al., ibid. 137, 164104 (2012)]. Here, we utilize density-fitted electron repulsion integrals to produce an efficient computational implementation. This approach is used to examine the effect of ionization on π-π interactions. For the benzene dimer radical cation, comparison against reference values indicates a good performance for open-shell SAPT0, except in cases with substantial charge transfer. For π stacking between hydrogen-bonded pairs of nucleobases, dispersion interactions still dominate binding, in spite of the creation of a positive charge.
Highly tuneable hole quantum dots in Ge-Si core-shell nanowires
Authors: Brauns Matthias , Ridderbos Joost , Li Ang , van der Wiel Wilfred G. , Bakkers Erik P. A. M. , Zwanenburg Floris A.
Published: October 2016

We define single quantum dots of lengths varying from 60 nm up to nearly half a micron in Ge-Si core-shell nanowires. The charging energies scale inversely with the quantum dot length between 18 and 4 meV. Subsequently, we split up a long dot into a double quantum dot with a separate control over the tunnel couplings and the electrochemical potential of each dot. Both single and double quantum dot configurations prove to be very stable and show excellent control over the electrostatic environment of the dots, making this system a highly versatile platform for spin-based quantum computing.
The behavior of active diffusiophoretic suspensions: An accelerated Laplacian dynamics study
Authors: Yan Wen , Brady John F.
Published: October 2016

Diffusiophoresis is the process by which a colloidal particle moves in response to the concentration gradient of a chemical solute. Chemically active particles generate solute concentration gradients via surface chemical reactions which can result in their own motion — the self-diffusiophoresis of Janus particles — and in the motion of other nearby particles — normal down-gradient diffusiophoresis. The long-range nature of the concentration disturbance created by a reactive particle results in strong interactions among particles and can lead to the formation of clusters and even coexisting dense and dilute regions often seen in active matter systems. In this work, we present a general method to determine the many-particle solute concentration field allowing the dynamic simulation of the motion of thousands of reactive particles. With the simulation method, we first clarify and demonstrate the notion of “chemical screening,” whereby the long-ranged interactions become exponentially screened, which is essential for otherwise diffusiophoretic suspensions would be unconditionally unstable. Simulations show that uniformly reactive particles, which do not self-propel, form loosely packed clusters but no coexistence is observed. The simulations also reveal that there is a stability threshold — when the “chemical fuel” concentration is low enough, thermal Brownian motion is able to overcome diffusiophoretic attraction. Janus particles that self-propel show coexistence, but, interestingly, the stability threshold for clustering is not affected by the self-motion.
Surface roughness stabilizes the clustering of self-propelled triangles
Authors: Ilse Sven Erik , Holm Christian , de Graaf Joost
Published: October 2016

Self-propelled particles can spontaneously form dense phases from a dilute suspension in a process referred to as motility-induced phase separation. The properties of the out-of-equilibrium structures that are formed are governed by the specifics of the particle interactions and the strength of the activity. Thus far, most studies into the formation of these structures have focused on spherical colloids, dumbbells, and rod-like particles endowed with various interaction potentials. Only a few studies have examined the collective behavior of more complex particle shapes. Here, we increase the geometric complexity and use molecular dynamics simulations to consider the structures formed by triangular self-propelled particles with surface roughness. These triangles either move towards their apex or towards their base, i.e., they possess a polarity. We find that apex-directed triangles cluster more readily, more stably, and have a smoother cluster interface than their base-directed counterparts. A difference between the two polarities is in line with the results of Wensink et al. [Phys. Rev. E 89, 010302 (2014)]; however, we obtain the reversed result when it comes to clustering, namely, that apex-directed triangles cluster more successfully. We further show that reducing the surface roughness negatively impacts the stability of the base-directed structures, suggesting that their formation is in large part due to surface roughness. Our results lay a solid foundation for future experimental and computational studies into the effect of roughness on the collective dynamics of swimmers.
Low-temperature high magnetic field powder x-ray diffraction setup for field-induced structural phase transition studies from 2 to 300 K and at 0 to 8-T field
Authors: Shahee Aga , Sharma Shivani , Kumar Dhirendra , Yadav Poonam , Bhardwaj Preeti , Ghodke Nandkishor , Singh Kiran , Lalla N. P. , Chaddah P.
Published: October 2016

A low-temperature and high magnetic field powder x-ray diffractometer (XRD) has been developed at UGC-DAE CSR (UGC: University Grant Commission, DAE: Department of Atomic Energy, and CSR: Consortium for scientific research), Indore, India. The setup has been developed around an 18 kW rotating anode x-ray source delivering Cu-Kα x-rays coming from a vertical line source. It works in a symmetric θ-2θ parallel beam geometry. It consists of a liquid helium cryostat with an 8 T split-pair Nb-Ti superconducting magnet comprising two x-ray windows each covering an angular range of 65°. This is mounted on a non-magnetic type heavy duty goniometer equipped with all necessary motions along with data collection accessories. The incident x-ray beam has been made parallel using a parabolic multilayer mirror. The scattered x-ray is detected using a NaI detector through a 0.1° acceptance solar collimator. To control the motions of the goniometer, a computer programme has been developed. The wide-angle scattering data can be collected in a range of 2°–115° of 2θ with a resolution of ∼0.1°. The whole setup is tightly shielded for the scattered x-rays using a lead hutch. The functioning of the goniometer and the artifacts arising possibly due to the effect of stray magnetic field on the goniometer motions, on the x-ray source, and on the detector have been characterized by collecting powder XRD data of a National Institute of Standards and Technology certified standard reference material LaB6 (SRM-660b) and Si powder in zero-field and in-field conditions. Occurrence of field induced structural-phase transitions has been demonstrated on various samples like Pr0.5Sr0.5MnO3, Nd0.49Sr0.51MnO3−δ and La0.175Pr0.45Ca0.375MnO3 by collecting data in zero field cool and field cool conditions.
A novel set-up to investigate the low-frequency spectra of aqueous solutions at high hydrostatic pressure
Authors: Knake L. , Vondracek H. , Havenith M.
Published: October 2016

We present a novel setup to investigate the low frequency (THz/FIR) spectra of an aqueous solution under high hydrostatic pressure (HHP). By integration of a diamond anvil cell into a THz Fourier transform spectrometer, we are able to record the absorption of bulk water in the pressure range from 1 bar to 10 kbar. The difference in intensity can directly be compared to the difference in extinction coefficients. The spectroscopic data reveal a blue shift of the H-bond stretch vibration at 180 cm−1, which is evidence of changes in the H-bond network dynamics.
Effect of magnetic field topology on quasi-stationary equilibrium, fluctuations, and flows in a simple toroidal device
Authors: Kumar Umesh , Thatipamula Shekar G , Ganesh R. , Saxena Y. C. , Raju D.
Published: October 2016

In a simple toroidal device, the plasma profiles and properties depend on toroidal magnetic field topology. For example, the toroidal connection length crucially controls the adiabatic or non-adiabatic nature of electron dynamics, which in turn governs the nature of instabilities, fluctuations, and transport, the latter of which governs the plasma mean profiles. We present the results of extensive experiments in a simple toroidal device obtained by controlling the mean parallel connection length L¯c, by application of external vertical component of magnetic field Bv, where Bv≤2% of toroidal magnetic field BT. Interestingly, for nearly closed field lines, which are characterized by large values of L¯c, it is found that flute like coherent modes are observed to be dominant and is accompanied by large poloidal flows. For small values of L¯c, the mean density on the high field side is seen to increase and the net poloidal flow reduces while a turbulent broad band in fluctuation spectrum is observed. Upon a gradual variation of L¯c from large to small values, continuous changes in mean plasma potential and density profiles, fluctuation, and poloidal flows demonstrate that in a simple toroidal device there exists a strong relationship between Lc, flows, and fluctuations. The net flow measured is found independent of the direction of Bv, but an asymmetry in the magnitude of the flow is found. The observed imbalance between the mean flow, fluctuation driven flow, and net flow is also discussed.
Darboux transformation and multi-soliton solutions of the Camassa-Holm equation and modified Camassa-Holm equation
Authors: Xia Baoqiang , Zhou Ruguang , Qiao Zhijun
Published: October 2016

In this paper, we propose a new approach to calculate multi-soliton solutions of Camassa-Holm (CH) equation and modified Camassa-Holm (MCH) equation with the aid of Darboux transformation (DT). The new approach simplifies the approach presented by Li and Zhang [Proc. R. Soc. London, Ser. A 460, 2617–2627 (2004)]. We first map the CH and MCH equation to a negative order KdV (NKdV) equation by a reciprocal transformation. Then we proceed to apply the DT to solve the NKdV equation in the usual way. Finally we invert the reciprocal transformation to recover the solutions of the CH equation and MCH equation.
Numerical simulation of a helical shape electric arc in the external axial magnetic field
Authors: Urusov R. M. , Urusova I. R.
Published: October 2016

Within the frameworks of non-stationary three-dimensional mathematical model, in approximation of a partial local thermodynamic equilibrium, a numerical calculation was made of characteristics of DC electric arc burning in a cylindrical channel in the uniform external axial magnetic field. The method of numerical simulation of the arc of helical shape in a uniform external axial magnetic field was proposed. This method consists in that that in the computational algorithm, a “scheme” analog of fluctuations for electrons temperature is supplemented. The “scheme” analogue of fluctuations increases a weak numerical asymmetry of electrons temperature distribution, which occurs randomly in the course of computing. This asymmetry can be “picked up” by the external magnetic field that continues to increase up to a certain value, which is sufficient for the formation of helical structure of the arc column. In the absence of fluctuations in the computational algorithm, the arc column in the external axial magnetic field maintains cylindrical axial symmetry, and a helical form of the arc is not observed.
Reducing parametric backscattering by polarization rotation
Authors: Barth Ido , Fisch Nathaniel J.
Published: October 2016

When a laser passes through underdense plasmas, Raman and Brillouin Backscattering can reflect a substantial portion of the incident laser energy. This is a major loss mechanism, for example, in employing lasers in inertial confinement fusion. However, by slow rotation of the incident linear polarization, the overall reflectivity can be reduced significantly. Particle in cell simulations show that, for parameters similar to those of indirect drive fusion experiments, polarization rotation reduces the reflectivity by a factor of 5. A general, fluid-model based analytical estimation for the reflectivity reduction agrees with simulations. However, in identifying the source of the backscatter reduction, it is difficult to disentangle the rotating polarization from the frequency separation based approach used to engineer the beam's polarization. Although the backscatter reduction arises similarly to other approaches that employ frequency separation, in the case here, the intensity remains constant in time.
A current-driven resistive instability and its nonlinear effects in simulations of coaxial helicity injection in a tokamak
Authors: Hooper E. B. , Sovinec C. R.
Published: October 2016

An instability observed in whole-device, resistive magnetohydrodynamic simulations of the driven phase of coaxial helicity injection in the National Spherical Torus eXperiment is identified as a current-driven resistive mode in an unusual geometry that transiently generates a current sheet. The mode consists of plasma flow velocity and magnetic field eddies in a tube aligned with the magnetic field at the surface of the injected magnetic flux. At low plasma temperatures (∼10–20 eV), the mode is benign, but at high temperatures (∼100 eV) its amplitude undergoes relaxation oscillations, broadening the layer of injected current and flow at the surface of the injected toroidal flux and background plasma. The poloidal-field structure is affected and the magnetic surface closure is generally prevented while the mode undergoes relaxation oscillations during injection. This study describes the mode and uses linearized numerical computations and an analytic slab model to identify the unstable mode.
Determination of nuclear quadrupolar parameters using singularities in field-swept NMR patterns
Authors: Ichijo Naoki , Takeda Kazuyuki , Yamada Kazuhiko , Takegoshi K.
Published: October 2016

We propose a simple data-analysis scheme to determine the coupling constant and the asymmetry parameter of nuclear quadrupolar interactions in field-swept nuclear magnetic resonance (NMR) for static powder samples. This approach correlates the quadrupolar parameters to the positions of the singularities, which can readily be found out as sharp peaks in the field-swept pattern. Moreover, the parameters can be determined without quantitative acquisition and elaborate calculation of the overall profile of the pattern. Since both experimental and computational efforts are significantly reduced, the approach presented in this work will enhance the power of the field-swept NMR for yet unexplored quadrupolar nuclei. We demonstrate this approach in 33S in α-S8 and 35Cl in chloranil. The accuracy of the obtained quadrupolar parameters is also discussed.
Plastic deformation mechanisms of ultrafine-grained copper in the temperature range of 4.2–300 K
Authors: Isaev N. V. , Grigorova T. V. , Mendiuk O. V. , Davydenko O. A. , Polishchuk S. S. , Geidarov V. G.
Published: October 2016

Main microstructural features of ultrafine-grained (UFG) polycrystalline oxygen-free copper (Cu–OF) obtained by direct and equal-channel angular hydrostatic extrusion were studied by EBSD and XRD methods. The effect of microstructure on the temperature dependences of the yield stress and strain rate sensitivity of the deforming stress was investigated using tensile and stress relaxation tests in the insufficiently studied temperature range of 4.2–300 K. Using thermal activation analysis it was established that in the range 77–200 K the rate of plastic deformation is controlled by the thermally activated mechanism of crossing the forest dislocations and its empirical parameters were obtained. The experimental anomalies below 77 K unaccountable by the forest crossing mechanism were explained by the inertial properties of dislocations revealed under conditions of high effective stress and low dynamic friction. The inversion of the temperature dependences of the activation volume observed above 200 K was attributed to the thermally activated detachment of dislocations from local pinning centers within the grain boundaries.
Optical anisotropy of InGaAs quantum wire arrays on vicinal (111)B GaAs
Authors: Kawazu Takuya
Published: October 2016

We studied the optical anisotropy of InGaAs quantum wire (QWR) arrays on vicinal (111)B GaAs. Polarized photoluminescence (PL) studies showed that the PL is polarized preferentially along [1–10], where the polarization degree ρ is about 9.4%. We also theoretically investigated the electronic states of the InGaAs QWR arrays to clarify how the optical anisotropy is affected by (1) the corrugated structure, (2) the strain effect including piezoelectricity, and (3) the thickness difference of the InGaAs layers on the two facets of the corrugated structure. While ρ for the corrugated structure is almost the same as that for a flat quantum well structure, the strain effects and the thickness difference result in the increases of ρ by about 1.9 and 2.5 times. The calculated results were compared to the experimental data. It was found that the effects of the strain and the thickness difference are important to explain the optical anisotropy of the InGaAs QWR arrays.
A thin-film cryotron suitable for use as an ultra-low-temperature switch
Authors: Lowell Peter J. , Mates John A. B. , Doriese W. Bertrand , Hilton Gene C. , Morgan Kelsey M. , Swetz Daniel S. , Ullom Joel N. , Schmidt Daniel R.
Published: October 2016

Low-temperature superconducting circuits have become important for many scientific applications. However, there are presently no high current-capacity switches (∼1 mA) with low power dissipation for sub-Kelvin operation. One candidate for a sub-Kelvin switch is the cryotron, a device in which the superconductivity of a wire is suppressed with a magnetic field. Here, we demonstrate a cryotron switch suitable for sub-Kelvin temperatures. In the closed state, the maximum device current is about 900 μA. The device is switched to its open state with 2 mA of control current and has a leakage of approximately 500 nA. The transition between the closed and open states of the device is faster than 200 ns, where the measurement is limited by the speed of our measurement apparatus. We also discuss low-temperature applications for our cryotron such as a single-pole, double-throw switch.
Influence of the Cu Content in Cu2ZnSn(S,Se)4 solar cell absorbers on order-disorder related band gap changes
Authors: Lang Mario , Renz Tobias , Mathes Niklas , Neuwirth Markus , Schnabel Thomas , Kalt Heinz , Hetterich Michael
Published: October 2016

We investigate the electronic structure and the radiative recombination in wet-chemically fabricated Cu2ZnSn(S,Se)4 solar cell absorbers utilizing photoluminescence (PL) and photoluminescence excitation (PLE) spectroscopy, focusing especially on the effects of varying Cu content. This includes the impact of the latter on the band gap energy and the change in band gap energy related to the order-disorder transition. Characteristic PL and PLE parameters like the energetic position of the PL maximum and the PL yield as a function of the excitation power as well as the PLE tailing parameter do not depend on composition indicating that the nature of the radiative transition is not altered by the Cu content. However, the band gap energy Eg significantly increases as a function of decreasing Cu content. This increase is more pronounced in the disordered than in the ordered atomic arrangement of Cu and Zn atoms in the Cu–Zn planes of the kesterite crystal structure.
A new study on the penetration of reactive species in their mass transfer processes in water by increasing the electron energy in plasmas
Authors: Jiang Jixiang , Tan Zhenyu , Shan Chunhong , Pan Jie , Pan Guangsheng , Liu Yadi , Chen Xinxian , Wang Xiaolong
Published: October 2016

In this work, the mass transfer of the reactive species from the plasmas in the water layer has been investigated by means of the numerical simulation based on the one-dimensional drift-diffusion model. The depth distributions of five main reactive species, OH, O3, HO2, O2−, and H2O2, have been presented, when considering the dissociative electron attachment (DEA) to the water molecule by increasing electron energy in the plasmas. The present work shows that the DEA to the water molecule plays an important role in the penetration of the species OH, O3, and HO2. With the increase in electron energy, HO2 quenches after the penetration depth of a few micrometers, becoming a short-living species, but the penetration depths of O3 and OH increase evidently, up to a few tens micrometers, which is of significance for the application of cold atmospheric-pressure plasmas in biomedical engineering. In addition, the contribution of each dominative reaction to production or loss of OH has also been calculated and analyzed under the different electron energies because of the importance of OH in the inactivation of biomolecules and in order to have a good knowledge of the mechanisms of OH production as well as its penetration in the water layer. The present work is a first effort toward the goal of increasing the different types of the reactive species that may interact with cellular components after the mass transfer of the plasmas in the water layer, by changing the discharge parameters of the plasmas.
Oxygen vacancy-driven evolution of structural and electrical properties in SrFeO3−δ thin films and a method of stabilization
Authors: Enriquez Erik , Chen Aiping , Harrell Zach , Lü Xujie , Dowden Paul , Koskelo Nicholas , Janoschek Marc , Chen Chonglin , Jia Quanxi
Published: October 2016

Epitaxial SrFeO3−δ (SFO) thin films have been grown on various substrates by pulsed laser deposition. The structural and electrical properties of SFO thin films are monitored with time in different atmospheres at room temperature, showing time-dependent crystal structure and electrical conductivity. The increased out-of-plane lattice parameter and resistivity over time are associated with the increased oxygen vacancies density in SFO thin films. The epitaxial strain plays an important role in determining the initial resistivity, and the sample environment determines the trend of resistivity change over time. An amorphous Al2O3 passivation layer has been found to be effective in stabilizing the structure and electrical properties of SFO thin films. This work explores time dependent structure and properties variation in oxide films and provides a way to stabilize thin film materials that are sensitive to oxygen vacancies.
Fabry-Pérot interference in a triple-gated quantum point contact
Authors: Maeda S. , Miyamoto S. , Fauzi M. H. , Nagase K. , Sato K. , Hirayama Y.
Published: October 2016

We demonstrated that a triple-gated GaAs quantum point contact, which has an additional surface gate between a pair of split gates to strengthen the lateral confinement, produces the well-defined quantized conductance and Fabry-Pérot-type (FP-type) oscillations on it even using a relatively low mobility wafer. A one-dimensional phenomenological model potential was developed to explain the oscillatory behavior. By combining the model calculations and dc bias spectroscopy, we obtained a detailed information about the energy scales of the oscillatory structures. The relationships between the FP-type oscillations and the anomaly below the first plateau will be addressed.
Ferromagnetic resonance study of composite Co/Ni - FeCoB free layers with perpendicular anisotropy
Authors: Devolder T. , Liu E. , Swerts J. , Couet S. , Lin T. , Mertens S. , Furnemont A. , Kar G. , De Boeck J.
Published: October 2016

We study the properties of composite free layers with perpendicular anisotropy. The free layers are made of a soft FeCoB layer ferromagnetically coupled by a variable spacer (Ta, W, Mo) to a very anisotropic [Co/Ni] multilayer embodied in a magnetic tunnel junction meant for spin torque memory applications. For this we use broadband ferromagnetic resonance to follow the field dependence of the acoustical and optical excitation of the composite free layer in both in-plane and out-of-plane applied fields. The modeling provides the interlayer exchange coupling, the anisotropies, and the damping factors. The popular Ta spacer is outperformed by W and even more by Mo, which combines the strongest interlayer exchange coupling without sacrificing anisotropies, damping factors, and transport properties.
Seasonal variation in gonorrhoea incidence among men who have sex with men
Authors: Li Bin , Bi Peng , Chow Eric P. F. , Donovan Basil , McNulty Anna , Ward Alison , Bell Charlotte , Fairley Christopher K.
Published: October 2016

Background
After reviewing urethral gonorrhoea cases among men who have sex with men (MSM) at the South Australia Specialist Sexual Health (SASSH) in Adelaide, Australia, we noticed peaks of gonorrhoea among MSM occurred predominantly in the first quarter of the year (January–March). The aim of this study was to formally test this hypothesis against data from a similar period at three sexual health services, one each in Adelaide, Melbourne and Sydney. Methods: This study was a retrospective analysis of computerised records at the three Australian sexual health services. Potential risk factors for urethral gonorrhoea among MSM were also reviewed at the SASSH. Results: More peaks of gonorrhoea cases were observed in the first quarter of the year in Adelaide and Sydney and in the second and fourth quarter in Melbourne. Factors independently associated with urethral gonorrhoea at the SASSH were being a young MSM, especially those aged 25–29 (odds ratio (OR) 2.66, 95% confidence interval (CI): 2.00–3.54), having more than one sexual partner (OR 1.71, 95% CI: 1.43–2.04), having had sex interstate and overseas (OR 1.52, 95% CI: 1.06–2.17), and presenting in the first quarter (OR 1.30, 95% CI: 1.10–1.55). Conclusion: Our data suggest that gonorrhoea among MSM occurs in a seasonal pattern, particularly late summer into early autumn. This has implications for the provision of health services over the year and for the timing of health promotion activities.
Superantigens hyperinduce inflammatory cytokines by enhancing the B7-2/CD28 costimulatory receptor interaction
Authors: Levy Revital , Rotfogel Ziv , Hillman Dalia , Popugailo Andrey , Arad Gila , Supper Emmanuelle , Osman Farhat , Kaempfer Raymond
Published: October 2016

Significance

Superantigens—bacterial virulence factors—cause toxic shock by hyperinducing inflammatory cytokines. T-cell activation is mediated both by antigen and by interaction between principal costimulatory receptors B7-2 and CD28. Superantigens must bind CD28 to elicit cytokine overexpression through a hitherto unknown mechanism. We show that, by binding not only CD28 but also its coligand B7-2 directly, superantigens potently enhance the B7-2/CD28 interaction, thereby inducing T-cell hyperactivation. Superantigens engage B7-2 and CD28 at their homodimer interfaces, far from where the receptors interact, demonstrating the regulatory properties of these interfaces. B7-2 dimer interface peptides attenuate cytokine overexpression and prevent superantigen lethality by blocking costimulatory receptor engagement by superantigen. Thus, bacterial superantigens induce a pathogenic “cytokine storm” by strongly enhancing formation of the B7-2/CD28 costimulatory axis.
Interfibrillar stiffening of echinoderm mutable collagenous tissue demonstrated at the nanoscale
Authors: Mo Jingyi , Prévost Sylvain F. , Blowes Liisa M. , Egertová Michaela , Terrill Nicholas J. , Wang Wen , Elphick Maurice R. , Gupta Himadri S.
Published: October 2016

Significance

Collagen plays crucial biomechanical roles in a wide array of animal tissues, but its mechanical properties remain largely static over short timescales. However, echinoderms (sea cucumbers, starfish) are striking exceptions to this rule, having “mutable collagenous tissue” with changeable mechanical properties, enabling complex locomotion, postural maintenance, defense, and reproductive strategies. Using a high-resolution X-ray probe that measures how the building blocks—fibrils—of echinoderm connective tissue stretch, slide, or reorient in real time, we show that sea cucumbers achieve this remarkable property by changing the stiffness of the matrix between individual fibrils, rather than the properties of the fibrils themselves. Understanding the mechanisms of mutability in this unique tissue may help design novel mechanically tunable synthetic biomaterials.
The Architecture of
Trypanosoma brucei
editosomes
Authors: McDermott Suzanne M. , Luo Jie , Carnes Jason , Ranish Jeff A. , Stuart Kenneth
Published: October 2016

Significance

Trypanosoma brucei
is a deadly kinetoplastid parasite that causes the human and veterinarian diseases African sleeping sickness and nagana. We combine chemical cross-linking and mass spectrometry, structural modeling, genetics, and biochemistry to define the global architecture of RNA editing “editosome” complexes in these parasites. Editosomes are unique to kinetoplastids, which also include
Trypanosoma cruzi
and
Leishmania
parasites that cause Chagas disease and Leishmaniases, respectively. Editosomes are essential for parasite viability and are promising drug targets. This work creates a comprehensive, highly detailed map of editosome protein proximities and interactions, and furthers our understanding of editosome protein function in
T. brucei
and other kinetoplastids, thus aiding the potential development of new therapeutics for the treatment of several different parasitic diseases.
Generation of an inducible colon-specific Cre enzyme mouse line for colon cancer research
Authors: Tetteh Paul W. , Kretzschmar Kai , Begthel Harry , van den Born Maaike , Korving Jeroen , Morsink Folkert , Farin Henner , van Es Johan H. , Offerhaus G. Johan A. , Clevers Hans
Published: October 2016

Significance

A major limitation of current mouse models of colorectal cancer (CRC) is that the cancer that develops is often significantly different from human colon cancer in terms of latency, intestinal location, or molecular signature. Carbonic anhydrase I (
Car1
) is a gene expressed by colonic epithelial cells. We generated an inducible
Car1

CreER

mouse model with Cre expression in the cecum and proximal colon. Mutations of genes that drive human CRC with our
Car1
CreER
mouse yielded tumors exclusively in the cecum and proximal colon. Differentiated colonic cells in the proximal colon with
Apc/Kras
mutations initiate tumors supporting a top-down model of intestinal tumorigenesis. The inducible
Car1
CreER
will be a useful model in studying human intestinal cancers originating from the proximal colon.
One-dimensional nanowires of pseudoboehmite (aluminum oxyhydroxide γ-AlOOH)
Authors: Iijima Sumio , Yumura Takashi , Liu Zheng
Published: October 2016

Significance

Pseudoboehmite (PB) is a poorly crystallized variant of boehmite, but its crystal structure and morphology have not been clearly understood. In particular, PB gel crystals are formed in an aqueous solution, so the interface between the crystalline surface and water is of crucial importance for understanding its properties and growth mechanism. Here we report the detailed structures of fibrous PB crystals obtained from high-resolution transmission electron microscopy and electron diffraction patterns. Some of the fibers consist of only two layers of an Al–O octahedral double-sheet ribbon structure, which is really a 1D structure. The findings will broaden the understandings in classical but important fields of colloid science and clay mineralogy.
Insulin resistance and diabetes caused by genetic or diet-induced KBTBD2 deficiency in mice
Authors: Zhang Zhao , Turer Emre , Li Xiaohong , Zhan Xiaoming , Choi Mihwa , Tang Miao , Press Amanda , Smith Steven R. , Divoux Adeline , Moresco Eva Marie Y. , Beutler Bruce
Published: October 2016

Significance

We report an essential regulator of insulin sensitivity. Mutations affecting this protein, KBTBD2, cause severe insulin-resistant diabetes, lipodystrophy, hepatic steatosis, and growth retardation. KBTBD2 is the substrate recognition subunit of a ubiquitin ligase, and its essential molecular target is p85α, the regulatory subunit of phosphoinositol-3-kinase. KBTBD2 is highly conserved among vertebrates and expressed in liver, brain, muscle, and adipocytes. In the absence of KBTBD2, p85α levels rise 30-fold in adipocytes, interrupting the insulin signal, which is fully restored by p85α knockout. Transfer of KBTBD2-sufficient adipose tissue to KBTBD2-deficient animals rescues insulin-resistant hyperglycemia. Within adipocytes, KBTBD2 expression is markedly down-regulated in response to a high-fat diet. This appears to be an important cause of the insulin resistance caused by obesity.
Depth psychology through the lens of Classical Yoga: a reconsideration of Jung’s ontic reality
Authors: Whitney Leanne
Published: October 2016

Jung, a self-proclaimed empiricist, resisted all metaphysical claims. Nevertheless his depth psychology hypothesized an unconscious agent, which we can never know directly. As a means of healing he implores us to loosen our resistance to the unconscious, for when ego-consciousness develops and maintains a relationship to the unconscious, human beings make the Creator conscious of His creation. Although not explicit in his theories, both the ego and the unconscious are more than psychological concepts for Jung; they are ontically real. Looking at Jung through the lens of Classical Yoga this paper invites a reconsideration of the Jungian ontic reality.
Regulation of GPCR expression through an interaction with CCT7, a subunit of the CCT/TRiC complex
Authors: Génier Samuel , Degrandmaison Jade , Moreau Pierrick , Labrecque Pascale , Hébert Terence E. , Parent Jean-Luc
Published: October 2016

Mechanisms that prevent aggregation and promote folding of nascent G protein–coupled receptors (GPCRs) remain poorly understood. We identified chaperonin containing TCP-1 subunit eta (CCT7) as an interacting partner of the β-isoform of thromboxane A2receptor (TPβ) by yeast two-hybrid screening. CCT7 coimmunoprecipitated with overexpressed TPβ and β2-adrenergic receptor (β2AR) in HEK 293 cells, but also with endogenous β2AR. CCT7 depletion by small interfering RNA reduced total and cell-surface expression of both receptors and caused redistribution of the receptors to juxtanuclear aggresomes, significantly more so for TPβ than β2AR. Interestingly, Hsp90 coimmunoprecipitated with β2AR but virtually not with TPβ, indicating that nascent GPCRs can adopt alternative folding pathways. In vitro pull-down assays showed that both receptors can interact directly with CCT7 through their third intracellular loops and C-termini. We demonstrate that Trp334in the TPβ C-terminus is critical for the CCT7 interaction and plays an important role in TPβ maturation and cell-surface expression. Of note, introducing a tryptophan in the corresponding position of the TPα isoform confers the CCT7-binding and maturation properties of TPβ. We show that an interaction with a subunit of the CCT/TCP-1 ring complex (TRiC) chaperonin complex is involved in regulating aggregation of nascent GPCRs and in promoting their proper maturation and expression.
Cultural Adaptation of Preventive Interventions in Hispanic Youth
Authors: St. George Sara M. , Parra-Cardona J. Rubén , Vidot Denise C. , Molleda Lourdes M. , Quevedo Terán Ana , Castillo Onetto Daniela , Benitez Gibbons Javiera , Prado Guillermo
Published: October 2016

Hispanics experience significant physical and behavioral health disparities compared to their racial and ethnic counterparts. To combat these health disparities, evidence-based interventions (EBIs) that prevent risk and promote protective factors within the broader context of culture must be systematically developed and disseminated. The purpose of this chapter is to describe key concepts related to the content and process of developing culturally relevant preventive interventions. The continuum of approaches for developing culturally relevant preventive interventions, including strengths and limitations, practical considerations, and recommendations for overcoming existing challenges, are discussed. Two exemplar preventive interventions targeting Hispanic youth and families, Criando con Amor: Promoviendo Armonia y Superación and Familias Unidas, are also highlighted. The approaches described in this chapter may maximize intervention effects and improve health outcomes for underrepresented minority groups, such as Hispanics.
Political Parties and Campaign Finance Networks
Authors: Herrnson Paul S. , Kirkland Justin H.
Published: October 2016

This chapter argues that to accurately gauge the impact of political parties on elections, it is necessary to look beyond traditional party committees and consider these organizations’ impact on the thousands of other groups that participate in the financing of campaigns. Using social network analysis and federal campaign finance data, the chapter demonstrates the existence of two distinctive hierarchical extended party networks, each comprising formal party organizations, campaign committees associated with members of Congress and congressional candidates, and PACs allied with one party. It also provides evidence suggesting party organizations’ influence over hundreds of millions of dollars in contributions and expenditures that flow within their networks. The chapter’s results have implications for party and interest group development and behavior, as well as legislative and electoral politics.
Human Rights and Transnational Advocacy Networks
Authors: Murdie Amanda , Polizzi Marc
Published: October 2016

Human rights advocates have been argued to be working as part of a larger “network” of actors supporting the respect and security of individuals. However, until recently, much scholarship in this area has used “network” as a synonym for “connected actors” instead of examining the network characteristics of advocacy actors and the ways in which the nature of the advocacy network could influence human rights outcomes. This chapter examines the growing literature that focuses on human rights advocacy using network theory and methodologies. It outlines both global and local data collection efforts and the state of the literature and addresses how this literature has drawn on the larger political networks literature. It concludes with a call for future work on how the network characteristics of advocacy actors influences both which human rights issues receive international attention and whether this attention translates into improvements in human rights practices on the ground.
Institutions and Policy Networks in Europe
Authors: Fischer Manuel
Published: October 2016

This chapter reviews the European literature on institutions and policy networks. Institutions provide actors with opportunities and constraints for negotiation and cooperation and thus influence the structure of policy networks. The chapter first presents studies on the influence of country- and sector-level institutions on the structure of policy networks. The respective literature deals with the influence of consensual democracy versus majoritarian democracy, corporatist systems of interest intermediation, multiple levels of governance, degrees of European Union integration, processes of liberalization and democratization, and policy-process-specific venues on policy networks. The chapter then discusses the positions and roles of state actors in policy networks. Due to their formal decision-making power, state actors are either networking targets or play a key role in terms of network integration, brokerage, or network management. The review concludes with a short discussion of commonalities and directions for future research.
The Imperative for Strategy Implementation
Authors: Hitt Michael A. , Jackson Susan E. , Carmona Salvador , Bierman Leonard , Shalley Christina E. , Wright Douglas Michael
Published: October 2016

Most of the research and writing in strategic management focuses on the formulation of the most appropriate strategies. Selecting the best strategy for firms to follow is very important to achieve and maintain a competitive advantage. However, many strategies fail not because they are improperly formulated, but because they are poorly implemented. Despite the importance of effectively implementing strategies, there is little research strategy implementation. Outside of the implementation of specific strategy types, such as mergers and acquisitions, perhaps the most prominent focus of strategy implementation research has been on matching the organizational structure to the strategy chosen. This handbook contributes to our understanding of strategy implementation and identifies considerable opportunities for future research on this important process, with a focus on resources, governance, human capital, and accounting-based control systems.
Organizational Design and Control Choices
Authors: Hofmann Christian , van Lent Laurence
Published: October 2016

Building on new insights from organizational economics, management accounting researchers have highlighted how incentive contracts and performance measure choices complement structural arrangements in firms. We discuss how “slow-moving” elements in organizational design, such as the allocation of decision rights to local managers and interdependencies between different parts of the production function, affect the working of incentives and performance measures. We pay attention to the empirical challenges that researchers face in this area and argues that mixed-method approaches in which economic models are combined with empirical evidence can help to build a body of evidence that is robust and admits cross-study accumulation of knowledge. Finally, we illustrate how recent economic models that incorporate other-regarding preferences can help to bridge the gap between economics-based research in management accounting and more traditional approaches that rely on the behavioral sciences.
Managing Human Capital
Authors: Ketchen David J. , Crook T. Russell , Todd Samuel Y. , Combs James G. , Woehr David J.
Published: October 2016

This article explores human resource (HR) management and its interrelationship with strategic human capital and performance. Drawing on data from 158 studies of human capital, the authors consider how synchronized systems of HR management practices affect human capital and how individual practices impact performance. The authors also look at the impact of synchronized systems of practices on performance in relation to human capital and existing resources. The authors describe resource-based theory that explains performance differences and how firms manage their strategic resources to enhance performance. Finally, the work compares the direct and indirect effects of HR practices and systems on performance.