bluuebunny/crossref_metadata_2025 huggingface dataset:
Multi-wavelength study of star formation properties in barred galaxies
Authors: Zhou Zhi-Min , Cao Chen , Wu Hong
Published: July 2013

Stellar bars are important internal drivers of the secular evolution of disk galaxies. Using a sample of nearby barred galaxies with weak and strong bars, we evaluate the correlations between star formation properties in different galactic structures and their associated bars, and try to interpret the complex process of bar-driven secular evolution. We find that weaker bars tend to associate with lower concentrical star formation activities, while stronger bars appear to have large scatter in the distribution of the global star formation activities. In general, the star formation activities in early- and late-type galaxies have different behavior, with similar star formation rate density distributions. In addition, there are only weak trends toward increased star formation activities in bulges and galaxies with stronger bars, which is consistent with previous works. Our results suggest that the different stages of the evolutionary sequence and many factors besides bars may contribute to the complexity of this process. Furthermore, significant correlations are found between the star formation activities in different galactic structures, in which barred galaxies with intense star formation in bulges tend to also have active star formation in their bars and disks. Most bulges have higher star formation densities than their associated bars and disks, indicating the presence of bar-driven evolution. Therefore, we derived a possible criterion (Figure 1) to quantify the different stages of a bar-driven evolutionary sequence. Future work is needed to improve on the uncertainties of this study.
Origin and Ionization of the Warm Ionized Gas in Massive Early-type Galaxies
Authors: Yan Renbin , Blanton Michael R.
Published: July 2013

Most early-type galaxies are not devoid of cold and warm gas. The origin and ionization of this gas reveal the intriguing ongoing evolution of these galaxies. In most cases, the warm ionized gas shows emission-line spectra similar to low-ionization nuclear emission-line regions (LINERs). Their ionization mechanism has been hotly debated. We will present evidence from line ratio gradient that rules out AGN and shocks as the dominant ionization mechanism, and suggests the ionizing sources follow the stellar density profile. Hot evolved stars are the favorite candidates but bring new puzzles.

This finding allows us to obtain a gas-phase metallicity calibration in these early-type galaxies, using the line emission. We will show how the metallicity of the warm gas depends on stellar mass and stellar age, and what it tells us about the origin of the warm gas in these galaxies.
Modelling the formation of today's massive ellipticals
Authors: Naab Thorsten
Published: July 2013

The discovery of a population of massive, compact and quiescent early-type galaxies has changed the view on plausible formation scenarios for the present day population of elliptical galaxies. Traditionally assumed formation histories dominated by 'single events' like early collapse or major mergers appear to be incomplete and have to be embedded in the context of hierarchical cosmological models with continuous gas accretion and the merging of small stellar systems (minor mergers). Once these processes are consistently taken into account the hierarchical models favor a two-phase assembly process and are in much better shape to capture the observed trends. We review some aspects of recent progress in the field.
The Effects of Focal Epileptic Activity on Regional Sensory-Evoked Neurovascular Coupling and Postictal Modulation of Bilateral Sensory Processing
Authors: Harris Sam , Bruyns-Haylett Michael , Kennerley Aneurin , Boorman Luke , Overton Paul G , Ma Hongtao , Zhao Mingrui , Schwartz Theodore H , Berwick Jason
Published: July 2013

While it is known that cortical sensory dysfunction may occur in focal neocortical epilepsy, it is unknown whether sensory-evoked neurovascular coupling is also disrupted during epileptiform activity. Addressing this open question may help to elucidate both the effects of focal neocortical epilepsy on sensory responses and the neurovascular characteristics of epileptogenic regions in sensory cortex. We therefore examined bilateral sensory-evoked neurovascular responses before, during, and after 4-aminopyridine (4-AP, 15 mmol/L, 1 μL) induced focal neocortical seizures in right vibrissal cortex of the rat. Stimulation consisted of electrical pulse trains (16 seconds, 5 Hz, 1.2 mA) presented to the mystacial pad. Consequent current-source density neural responses and epileptic activity in both cortices and across laminae were recorded via two 16-channel microelectrodes bilaterally implanted in vibrissal cortices. Concurrent two-dimensional optical imaging spectroscopy was used to produce spatiotemporal maps of total, oxy-, and deoxy-hemoglobin concentration. Compared with control, sensory-evoked neurovascular coupling was altered during ictal activity, but conserved postictally in both ipsilateral and contralateral vibrissal cortices, despite neurovascular responses being significantly reduced in the former, and enhanced in the latter. Our results provide insights into sensory-evoked neurovascular dynamics and coupling in epilepsy, and may have implications for the localization of epileptogenic foci and neighboring eloquent cortex.
Designing tensile ductility in metallic glasses
Authors: Sarac Baran , Schroers Jan
Published: July 2013

Effectiveness of a second phase in metallic glass heterostructures to improve mechanical properties varies widely. Unfortunately, methods to fabricate such heterostructures like foams and composites do not allow controlled variation of structural features. Here we report a novel strategy, which allows us to vary heterostructural features independently, thereby enabling a systematic and quantitative study. Our approach reveals the optimal microstructural architecture for metallic glass heterostructures to achieve tensile ductility. Critical design aspect is a soft second phase, which is most effective when spacing between the second phase assumes the critical crack length of the metallic glass. This spacing should coincide with the second phase’s size, and beyond, the specific second phase morphology of the heterostructure is crucial. These toughening strategies are only effective in samples that are large compared with the spacing of the second phase. The identified design aspects provide guidance in designing tensile ductility into metallic glasses.
Forecasting large aftershocks within one day after the main shock
Authors: Omi Takahiro , Ogata Yosihiko , Hirata Yoshito , Aihara Kazuyuki
Published: July 2013

Forecasting the aftershock probability has been performed by the authorities to mitigate hazards in the disaster area after a main shock. However, despite the fact that most of large aftershocks occur within a day from the main shock, the operational forecasting has been very difficult during this time-period due to incomplete recording of early aftershocks. Here we propose a real-time method for efficiently forecasting the occurrence rates of potential aftershocks using systematically incomplete observations that are available in a few hours after the main shocks. We demonstrate the method's utility by retrospective early forecasting of the aftershock activity of the 2011 Tohoku-Oki Earthquake of M9.0 in Japan. Furthermore, we compare the results by the real-time data with the compiled preliminary data to examine robustness of the present method for the aftershocks of a recent inland earthquake in Japan.
Floquet bound states in the continuum
Authors: Longhi Stefano , Valle Giuseppe Della
Published: July 2013

Quantum mechanics predicts that certain stationary potentials can sustain bound states with an energy buried in the continuous spectrum of scattered states, the so-called bound states in the continuum (BIC). Originally regarded as mathematical curiosities, BIC have found an increasing interest in recent years, particularly in quantum and classical transport of matter and optical waves in mesoscopic and photonic systems where the underlying potential can be judiciously tailored. Most of our knowledge of BIC is so far restricted to static potentials. Here we introduce a new kind of BIC, referred to as Floquet BIC, which corresponds to a normalizable Floquet state of a time-periodic Hamiltonian with a quasienergy embedded into the spectrum of Floquet scattered states. We discuss the appearance of Floquet BIC states in a tight-binding lattice model driven by an ac field in the proximity of the dynamic localization regime.
Dynamics of cavitation clouds within a high-intensity focused ultrasonic beam
Authors: Lu Yuan , Katz Joseph , Prosperetti Andrea
Published: July 2013

In this experimental study, we generate a 500 kHz high-intensity focused ultrasonic beam, with pressure amplitude in the focal zone of up to 1.9 MPa, in initially quiescent water. The resulting pressure field and behavior of the cavitation bubbles are measured using high-speed digital in-line holography. Variations in the water density and refractive index are used for determining the spatial distribution of the acoustic pressure nonintrusively. Several cavitation phenomena occur within the acoustic partially standing wave caused by the reflection of sound from the walls of the test chamber. At all sound levels, bubbly layers form in the periphery of the focal zone in the pressure nodes of the partial standing wave. At high sound levels, clouds of vapor microbubbles are generated and migrate in the direction of the acoustic beam. Both the cloud size and velocity vary periodically, with the diameter peaking at the pressure nodes and velocity at the antinodes. A simple model involving linearized bubble dynamics, Bjerknes forces, sound attenuation by the cloud, added mass, and drag is used to predict the periodic velocity of the bubble cloud, as well as qualitatively explain the causes for the variations in the cloud size. The analysis shows that the primary Bjerknes force and drag dominate the cloud motion, and suggests that the secondary Bjerknes force causes the oscillations in the cloud size.
The effect of interface movement and viscosity variation on the stability of a diffusive interface between aqueous and gaseous CO2
Authors: Meulenbroek Bernard , Farajzadeh Rouhollah , Bruining Hans
Published: July 2013

Carbon dioxide injected in an aquifer rises quickly to the top of the reservoir and forms a gas cap from where it diffuses into the underlying water layer. Transfer of the CO2 to the aqueous phase below is enhanced due to the high density of the carbon dioxide containing aqueous phase. This paper investigates the behavior of the diffusive interface in an enclosed space in which initially the upper part is filled with pure carbon dioxide and the lower part with liquid. Our analysis differs from a conventional analysis as we take the movement of the diffusive interface due to mass transfer and the composition dependent viscosity in the aqueous phase into account. The same formalism can also be used to describe the situation when an oil layer is underlying the gas cap. Therefore we prefer to call the lower phase the liquid phase. In this paper we include these two effects into the stability analysis of a diffusive interface between CO2 and a liquid in the gravity field. We identify the relevant bifurcation parameter as q = εRa, where ε is the width of the interface. This implies the (well known) scaling of the critical time ∼Ra−2 and wavelength ∼Ra−1(The critical time tc and critical wavelength kc are defined as follows: σ(k) ⩽ 0 ∀t ⩽ tc; equality only holds for t = tc and k = kc). Inclusion of the interface upward movement leads to earlier destabilization of the system. Increasing viscosity for increasing CO2 concentration stabilizes the system. The theoretical results are compared to bulk flow visual experiments using the Schlieren technique to follow finger development in aquifer sequestration of CO2. In the appendix, we include a detailed derivation of the dispersion relation σ(k) in the Hele-Shaw case [C. T. Tan and G. M. Homsy, Phys. Fluids 29, 3549–3556 (1986)]10.1063/1.865832 which is nowhere explicitly given.
Novel in situ cell for Raman diagnostics of lithium-ion batteries
Authors: Gross T. , Giebeler L. , Hess C.
Published: July 2013

A novel in situ cell for Raman diagnostics of working lithium-ion batteries is described. The design closely mimics that of standard battery testing cells and therefore allows to obtain Raman spectra under representative electrochemical conditions. Both cathode and anode materials can be studied. First results on the intercalation of a Li1−xCoO2 cathode material demonstrate the potential of the experimental approach for structural studies and underline the importance of studying lithium-ion batteries at work.
Analyzing the uniformity of the generated magnetic field by a practical one-dimensional Helmholtz coils system
Authors: Beiranvand R.
Published: July 2013

Using the Helmholtz coils system is one of the most suitable approaches which have been introduced for generating uniform magnetic fields. In this paper, uniformity of the generated magnetic field by a practical one-dimensional (1D) Helmholtz coils system has been analyzed, mathematically. For this purpose, relationships between the magnetic field uniformity and different practical unavoidable mismatches have been extracted. The theoretical analysis clearly demonstrates the effect of assembly misalignments and manufacturing mismatches on the magnetic field achieved by a practical 1D Helmholtz coils system. The given analyses have been confirmed by the experimental results which are in good agreement with the calculated values. This analysis and the experimental results illustrate that to achieve a very high uniform magnetic field, practical assembly misalignments, and manufacturing mismatches must be as small as possible, and the background magnetic field distortion must be avoided, too. The results of this work are important in the design of instruments and systems where Helmholtz coils are used.
Miniature environmental chamber enabling in situ scanning probe microscopy within reactive environments
Authors: Nonnenmann Stephen S. , Bonnell Dawn A.
Published: July 2013

Developments in solid oxide fuel cells (SOFCs) continue to be one of the most intensely studied areas involving energy-producing systems, in an attempt to partially alleviate rapidly growing energy concerns. Direct, experimental observation of the governing electrochemical processes have remained largely elusive, due to high operating temperatures in the range of 400 °C–1000 °C. Here we outline the design and development of a miniature environmental chamber that enables a standard atomic force microscopes access to realistic SOFC operating conditions (T = 600 °C) for direct interrogation of electrochemical phenomena within SOFC cross-sections.
A joint theoretical/experimental study of the structure, dynamics, and Li+ transport in bis([tri]fluoro[methane]sulfonyl)imide [T]FSI-based ionic liquids
Authors: Solano C. J. F. , Jeremias S. , Paillard E. , Beljonne D. , Lazzaroni R.
Published: July 2013

The structure and dynamics of N-butyl-N-methyl pyrrolidinium+ bis([tri]fluoro[methane]sulfonyl)imide− (\documentclass[12pt]{minimal}\begin{document}${\rm PYR}_{14}^+$\end{document} PYR 14+-[T]FSI−) ionic liquids doped with Li(T)FSI are investigated by combining experimental measurements to molecular dynamics simulations. The polarizable force field calculations indicate that the lithium cations are coordinated by (T)FSI anion oxygens forming lithium adducts stabilized over a large temperature range by strong Li–O bonds. Lithium aggregation is found to be negligible at the doping level considered here (10% mole fraction), and Li+ diffusion occurs primarily by exchanging the (T)FSI anions in their first coordination shell. The resulting calculated transport properties are in good agreement with the corresponding nuclear magnetic resonance data.
Influence of adsorption kinetics on stress evolution in magnetron-sputtered SiO2 and SiNx films
Authors: Li Jingping , Fang Ming , He Hongbo , Shao Jianda , Li Zhaoyang
Published: July 2013

An in situ multi-beam optical sensor system was used to monitor and analyze the force per unit width (F/w) and stress evolution during several stages in magnetron-sputtered SiO2 and SiNx films. Stress was observed to relieve quickly after interrupt and recover rapidly after growth resumption in both films. Stress relief was reversible in SiO2 film but partial reversible in SiNx film. Stress relief results from both physical and chemical adsorption. Stress recovery is caused by physical desorption. And chemical adsorption results in an irreversible stress relief component. No chemical adsorption occurs in SiO2 film because of the stable chemical structure. The relationship between adsorption kinetics and films' mechanical behavior is revealed.
Tunable dielectric and ferroelectric properties in heteroepitaxial PbZr0.52Ti0.48O3/La0.625Ca0.375MnO3 thin films
Authors: Yang Shengwei , Dong Sining , Liu Yukuai , Yao Yiping , Yin Yuewei , Li Xiaoguang
Published: July 2013

In this work, the PbZr0.52Ti0.48O3/La0.625Ca0.375MnO3 (PZT/LCMO) thin films show a large magnetodielectric effect up to 52% at 3 MHz in a field of 0.8 T near the ferromagnetic Curie temperature Tc of LCMO. According to the equivalent RC-circuit fitting, the large magnetodielectric effect is found to be closely related to the interface behaviors between PZT and LCMO, which exhibits impressive magnetodielectric and magnetoresistance effects. Meanwhile, the extrinsic change of the ferroelectric coercive field Ec and remnant polarization Pr can be explained by the variations of voltage drop and space-charge related polarization. These findings improve our comprehension of magnetoelectric coupling in multiferroic heterostructure, and may provide potential application for multifunctional devices in spintronics.
Millimeter-wave photoresponse due to excitation of two-dimensional plasmons in InGaAs/InP high-electron-mobility transistors
Authors: Nader Esfahani N. , Peale R. E. , Buchwald W. R. , Fredricksen C. J. , Hendrickson J. R. , Cleary J. W.
Published: July 2013

A polarized photoresponse to mm-wave radiation over the frequency range of 40 to 108 GHz is demonstrated in a grating-gated high electron mobility transistor (HEMT) formed by an InGaAs/InP heterostructure. The photoresponse is observed within the plasmon resonance absorption band of the HEMT, whose gate consists of a 9 μm period grating that couples incident radiation to plasmons in the 2D electron gas. Gate-bias changes the channel carrier concentration, causing a corresponding change in photoresponse in agreement with theoretical expectations for the shift in the plasmon resonance band. The noise equivalent power is estimated to be 235 pW/Hz1/2.
Study of magnetization reversal in LaCr1−xFexO3 compounds
Authors: Bora Tribedi , Ravi S.
Published: July 2013

Single phase samples of LaCr1−xFexO3 for x = 0–0.50 were prepared and their magnetic properties were studied to understand the magnetization reversal. Magnetization reversal was observed even for 5 at. % of Fe doping and it persisted up to x = 0.15. Ferromagnetic like behavior with a large coercive field of the order of 0.5 T was observed in the intermediate composition range of x = 0.20–0.40. However, for x = 0.45 and 0.50, magnetization reversal was again observed. Magnetization reversal was studied in detail by carrying out field cooled magnetization measurements for different applied magnetic fields. The mechanism of magnetization reversal for low Fe concentrations (x = 0.05–0.15) is basically due to the paramagnetic behavior of doped Fe ions under the influence of negative internal field arising from the antiferromagnetically ordered Cr3+ ions. The value of maximum negative internal field was estimated to be −3.5 kOe. On the other hand, the mechanism of magnetization reversal for x = 0.45 and 0.50 samples is found to be quite different. They could be quantitatively analyzed based on the model, where the competition between single ion anisotropy and Dzyaloshinsky–Moriya interaction is taken into account.
Positional dependence of energy gap on line defect in armchair graphene nanoribbons: Two-terminal transport and related issues
Authors: Dutta Paramita , Maiti Santanu K. , Karmakar S. N.
Published: July 2013

The characteristics of energy band spectrum of armchair graphene nanoribbons in the presence of line defect are analyzed within a simple non-interacting tight-binding framework. In metallic nanoribbons, an energy gap may or may not appear in the band spectrum depending on the location of the defect line, while in semiconducting ribbons, the gaps are customized, yielding the potential applicabilities of graphene nanoribbons in nanoscale electronic devices. With a more general model, we also investigate two-terminal electron transport using Green's function formalism.
Optoelectronic properties of p-i-n heterojunctions based on germanium nanocrystals
Authors: Parola S. , Quesnel E. , Muffato V. , Xie L. , Leifer K. , Coignus J. , Slaoui A.
Published: July 2013

We investigated the possibility of using physical vapour deposited Ge nanocrystals (NCs) in optoelectronic devices such as solar cells. We have prepared p-i-n heterojunctions based on p+-doped Si substrate/undoped Ge NCs/ZnO:Al layer stacks and their optoelectronic properties were characterised. Under light, the generation of photo-carriers from the Ge NCs themselves was demonstrated. The photovoltaic behaviour of the p-i-n structure was also highlighted, with a measured Voc of 224 mV compared to 580 mV in theory. The discrepancy between theory and experiment was discussed on the basis of TEM observations, optical and carrier generation measurements as well as modelling.
Wavelength tuning and thermal dynamics of continuous-wave mid-infrared distributed feedback quantum cascade lasers
Authors: Tombez Lionel , Cappelli Francesco , Schilt Stéphane , Di Domenico Gianni , Bartalini Saverio , Hofstetter Daniel
Published: July 2013

We report on the wavelength tuning dynamics in continuous-wave distributed feedback quantum cascade lasers (QCLs). The wavelength tuning response for direct current modulation of two mid-IR QCLs from different suppliers was measured from 10 Hz up to several MHz using ro-vibrational molecular resonances as frequency-to-intensity converters. Unlike the output intensity, which can be modulated up to several gigahertz, the frequency-modulation bandwidth was found to be on the order of 200 kHz, limited by the laser thermal dynamics. A non-negligible roll-off and a significant phase shift are observed above a few hundred hertz already and explained by a thermal model.
Successive phase transformation in stoichiometric glassy Li2Ge4O9: Isothermal and nonisothermal study
Authors: Takahashi Yoshihiro , Kunitomo Jun , Miyazaki Takamichi , Osada Minoru , Fujiwara Takumi
Published: July 2013

Stoichiometric glassy germanate is an important material in geophysics and materials science. Despite the binary Li2O−GeO2 system being primitive, its crystallization mechanism remains undetermined. In this study, we investigated crystallization and structural ordering in glassy ferroelectric Li2Ge4O9. Using isothermally and nonisothermally prepared samples, we demonstrated that the glassy Li2Ge4O9 shows no direct structural change to the stoichiometric phase; it rather forms α-GeO2 nanocrystals, i.e., it undergoes successive phase transformation. The results suggest that the metastable immiscibility is related to the ordering that occurs prior to crystallization of the stoichiometric phase.
Temperature dependent optical properties of silver from spectroscopic ellipsometry and density functional theory calculations
Authors: Sundari S. Tripura , Chandra Sharat , Tyagi A. K.
Published: July 2013

A detailed analysis of temperature dependence of optical constants of silver thin film measured by spectroscopic ellipsometry in the energy range 1.4 to 5 eV for temperatures ranging from 300 K to 650 K in steps of 50 K is presented in this paper. A microstructure modeling based on Bruggeman effective medium approximation is carried out on the temperature dependent optical constants. A red shift of ∼300 meV accompanied by a broadening of the interband transition is observed and an additional weak absorption edge emerges from the lower energy side of main interband absorption transition at 550 K. Drude model is applied to perform the analysis of dielectric function in the low energy region. The energy loss function −Im(1/ε) shows large damping with increasing temperature and this is a consequence of increasing magnitude of ε2 resulting from the composite transition in the region where ε1 is very small. These experimental results are corroborated with first principles electronic structure calculations using the full potential linearized augmented plane wave method within the frame-work of density functional theory.
High-throughput formation and control of monodisperse liquid crystals droplets driven by an alternating current electric field in a microfluidic device
Authors: Belloul M. , Bartolo J.-F. , Ziraoui B. , Coldren F. , Taly V. , El Abed A. I.
Published: July 2013

We investigate the effect of an applied ac high voltage on a confined stable nematic liquid crystal (LC) in a microfluidic device and show that this actuation leads to the formation of highly monodisperse microdroplets with an unexpected constant mean size over a large interval of the forcing frequency F and with a droplets production frequency f≃2F. We show also that despite the nonlinear feature of the droplets formation mechanism, droplets size, and size distribution are governed simply by the LC flow rate Qd and the forcing frequency F.
Band alignment study of lattice-matched InAlP and Ge using x-ray photoelectron spectroscopy
Authors: Owen Man Hon Samuel , Guo Cheng , Chen Shu-Han , Wan Cheng-Tien , Cheng Chao-Ching , Wu Cheng-Hsien , Ko Chih-Hsin , Wann Clement H. , Ivana  , Zhang Zheng , Sheng Pan Ji , Yeo Yee-Chia
Published: July 2013

Lattice-matched In0.48Al0.52P was grown on a p-type Ge(100) substrate by metal-organic chemical vapor deposition, and the band-alignment of In0.48Al0.52P on Ge substrate was obtained by high resolution x-ray photoelectron spectroscopy. The valence band offset for the InAlP/Ge(100) interface was found to be 0.86 eV, with a corresponding conduction band offset of 0.84 eV. From the values obtained, the energy band diagram of InAlP/Ge interface is found to be of type I.
Pseudomorphic GeSn/Ge(001) quantum wells: Examining indirect band gap bowing
Authors: Tonkikh Alexander A. , Eisenschmidt Christian , Talalaev Vadim G. , Zakharov Nikolay D. , Schilling Joerg , Schmidt Georg , Werner Peter
Published: July 2013

A study of the bandgap character of compressively strained GeSn0.060-0.091/Ge(001) quantum wells grown by molecular beam epitaxy is reported. The built-in strain in GeSn wells leads to an increased separation between L and Γ conduction band minima. The prevalent indirect interband transitions in GeSn were probed by photoluminescence spectroscopy. As a result we could simulate the L-valley bowing parameter in GeSn alloys, bL = 0.80 ± 0.06 eV at 10 K. From this we conclude that even compressively strained GeSn/Ge(001) alloys could become direct band gap semiconductors at the Sn-fraction higher than 17.0 at. %.
Microsphere-coupled organic waveguides: Preparation, remote excitation of whispering gallery modes and waveguiding property
Authors: Chikkaraddy Rohit , Dasgupta Arindam , Dutta Gupta S. , Pavan Kumar G. V.
Published: July 2013

In this letter, we show how organic molecular waveguides of 1,5-diaminoanthraquinone molecules can be grown on a silica microsphere to obtain microsphere-coupled organic waveguides (MOWs). Using such MOWs, we remotely excite and detect whispering gallery modes (WGMs) of the attached microsphere. Interestingly, these WGMs showed mode-splitting and mode-mixing due to broken azimuthal symmetry of the microsphere. Furthermore, the waveguiding characteristics of MOWs showed a quadrupole intensity pattern as a function of input polarization. The presented geometry can be an excellent test-bed to study fundamental aspects of coupled resonant systems, and their properties can be harnessed in nano- and bio-photonics.
Experimental and first-principles study of ferromagnetism in Mn-doped zinc stannate nanowires
Authors: Deng Rui , Zhou Hang , Li Yong-Feng , Wu Tom , Yao Bin , Qin Jie-Ming , Wan Yu-Chun , Jiang Da-Yong , Liang Qing-Cheng , Liu Lei
Published: July 2013

Room temperature ferromagnetism was observed in Mn-doped zinc stannate (ZTO:Mn) nanowires, which were prepared by chemical vapor transport. Structural and magnetic properties and Mn chemical states of ZTO:Mn nanowires were investigated by X-ray diffraction, superconducting quantum interference device (SQUID) magnetometry and X-ray photoelectron spectroscopy. Manganese predominantly existed as Mn2+ and substituted for Zn (MnZn) in ZTO:Mn. This conclusion was supported by first-principles calculations. MnZn in ZTO:Mn had a lower formation energy than that of Mn substituted for Sn (MnSn). The nearest neighbor MnZn in ZTO stabilized ferromagnetic coupling. This observation supported the experimental results.
Broad defect depth distribution in germanium substrates induced by CF4 plasma
Authors: Kusumandari  , Taoka N. , Takeuchi W. , Fukudome M. , Sakashita M. , Nakatsuka O. , Zaima S.
Published: July 2013

The effects of Ar and CF4 plasma on defect formation in Sb-doped Ge substrates were investigated using deep-level transient spectroscopy. Whereas the Ar plasma was found to induce defects with an energy level of 0.31 eV below the conduction band minimum, the CF4 plasma gave rise to many different electron and hole traps. The electron trap with the broadest depth distribution was associated with Sb and interstitials, which extended to a depth of about 3 μm from the Ge surface. These results strongly suggest that the appropriate choice of gas is important during plasma etching of Ge etching in order to reduce plasma-induced damage.
Superparamagnetic response of Fe-coated W tips in spin-polarized scanning tunneling microscopy
Authors: Phark Soo-hyon , Fischer Jeison A. , Corbetta Marco , Sander Dirk , Kirschner Jürgen
Published: July 2013

We performed spin-polarized scanning tunneling spectroscopy on biatomic-layer-high Co nanoislands grown on Cu(111) in magnetic fields oriented normal to the sample surface, with Fe-coated W tips. Increasing the temperature from 10 to 30 K, we observe a reduced slope of the differential conductance around zero field. A quantitative analysis of the field- and temperature-dependent differential conductance data in the framework of superparamagnetism as described by a Langevin function gives an excellent description of the experimental results. The analysis suggests that a Fe nano-apex at the W tip, which is composed of 220–300 Fe atoms, determines the magnetic response of the tip.
Evolution of a health navigator model of care within a primary care setting: a case study
Authors: Doolan-Noble Fiona , Smith Danielle , Gauld Robin , Waters Debra L. , Cooke Anthony , Reriti Helen
Published: July 2013

Objective.
Patient navigation originated as an approach for reducing disparities in cancer care and consequent health outcomes. Over time navigator models have evolved and been used to address various health issues in differing contexts. This case study outlines the evolution, purpose and effects of a lay-led health navigator model in a deprived, sparsely populated, New Zealand rural setting, where primary care services are frequently understaffed and routinely overstretched.

Methods.
Routinely collected service utilisation data, survey results and health navigator interview data were utilised to illustrate the client group the service works with, why primary care refer to the service, as well as lessons learned from implementation to ongoing service provision.

Results.
Those referred to the navigator service generally represented the most vulnerable in the community. Survey respondents, overall, were highly satisfied with the service. Navigators identified barriers and facilitators to implementation, as well as ongoing obstacles and enablers to service provision.

Conclusions.
This lay-led navigator service provided support to a group of unwell individuals, with few resources and multiple barriers to negotiate, and has effectively engaged with health and social care services, while overcoming various barriers and obstacles to its establishment and ongoing operation.

What is known about the topic?
Patient navigation models of care were first employed in the 1990s, as a strategy to increase the uptake of cancer screening among disadvantaged women. They have since expanded across the cancer care continuum, but despite favourable findings, information regarding their potential in other settings is limited.

What does this paper add?
This paper provides a perspective on lay-led navigation services within a rural New Zealand primary care setting. The views of primary care professionals regarding the role and value of the service are provide, as is a summary of the key lessons learnt over the implementation, establishment and ongoing service delivery phases of the programme.

What are the implications for practitioners?
This case study proposes that lay-led navigation services can provide practical support to primary care; assisting it to meet the needs of patients living with multiple chronic conditions and social challenges.
Utilisation of Large White × Mong Cai crossbred sows and Duroc and stress negative Piétrain boars for the production of fattening pigs under household conditions in northern Vietnam
Authors: Luc D. D. , Clinquart A. , Ton V. D. , Binh D. V. , Leroy P. , Farnir F.
Published: July 2013

The objective of this study was to compare the effects of Duroc (DU) and stress-negative Piétrain (PI) as terminal sires mated to F1(Large White × Mong Cai) sows (F1) on productivity, carcass characteristics, meat quality, and meat chemical composition under household conditions in Hai Duong province, Vietnam. The reproduction performances were based on 74 litters of 42 F1 sows from 12 households and the semen from 11 Duroc and 10 Piétrain boars. Data on production and carcass traits were collected from 76 DU × F1 and 67 PI × F1 crossbred fattening pigs. Longissimus dorsi samples from 55 DU × F1 and 37 PI × F1 were analysed to determine meat quality and meat chemical composition. The results show that household affected production, carcass, and meat quality traits (P < 0.05) as well as reproduction (weights at birth and weaning, P < 0.01). In contrast, boar breed did not influence (P > 0.06) reproduction traits (except individual weight of pigs born alive and weaned pigs, P < 0.01), production traits, meat chemical composition, or meat quality (except pH at 4 days post mortem, P < 0.05). Lean meat percentage of Piétrain-sired pigs was higher than that of Duroc-sired pigs (P < 0.05). The use of Piétrain boars does not affect reproduction performance, growth rate, or meat quality but does improve lean meat percentage compared with Duroc boars. This suggests that the use of stress-negative Piétrain boars as terminal sires would improve lean meat percentage under household conditions in North Vietnam.
Repeatability and frequency of in-paddock sheep walk-over weights: implications for flock-based management
Authors: Brown D. J. , Savage D. B. , Hinch G. N.
Published: July 2013

The ability to monitor average liveweight of a sheep flock provides livestock managers the opportunity to nutritionally manage their flock for higher productivity. Mob-based walk-over weighing (MBWOW) is a remote weighing concept for sheep flocks whereby liveweights are collected as the animals pass freely over a strategically placed weighing platform. We tested the hypothesis that the repeatability and frequency of MBWOW data are sufficient to generate sheep flock average liveweight estimates with a 95% confidence interval (CI) of <2 kg over a 5-day time period. These criteria were considered reasonable, in terms of accuracy and timeliness, for application in a commercial context. Radio frequency-identified WOW data were obtained from four sheep flocks in south-eastern New South Wales, representing a mix of age and breeds, as sheep traversed a remote weighing platform to and from some form of incentive. The repeatability and frequency of three forms of radio frequency-identified WOW data, being raw (unfiltered), course-filtered (filtered to remove all sheep weights outside the flock weight range) and fine-filtered (filtered to remove all sheep weights outside a 25% range of a recent flock average reference weight), were used in a simulation to test the 95% CI of 1- and 5-day MBWOW liveweight capture periods (samples). All data-filtering approaches over a 5-day sample generated flock average liveweight estimates with 95% CI of <2 kg, thus meeting the hypothesis criteria. One-day samples generated flock average liveweight estimates with 95% CI of >2 kg and data filtering, although reducing the 95% CI, did not bring it below the hypothesis criteria. Thus, when the appropriate data handling technique is used, MBWOW may provide information suitable for sheep management decision-making in a commercial context.
Iridium(III) Complexes Containing 1,10-Phenanthroline and Derivatives: Synthetic, Stereochemical, and Structural Studies, and their Antimicrobial Activity
Authors: Pandrala Mallesh , Li Fangfei , Wallace Lynne , Steel Peter J. , Moore II Barry , Autschbach Jochen , Collins J. Grant , Keene F. Richard
Published: July 2013

A convenient synthetic strategy is reported for the series of complexes [Ir(pp)3]3+ (where pp = phen, Me2phen and Me4phen) through the intermediacy of the appropriate [Ir(pp)2(CF3SO3)2]+ species. In the case of [Ir(phen)3]3+, the cation was resolved into its enantiomeric forms, for which the absolute configurations were determined by X-ray diffraction. The availability for the first time of the CD spectra allowed comparison with computed CD spectra. Measurement of the antimicrobial activity of the [Ir(pp)3]3+ species {and the [Ir(pp)2X2]+ (X = Cl–, CF3SO3–) precursors involved in their synthesis}, as well as cell uptake studies with the four bacterial strains S. aureus, methicillin-resistant S. aureus (MRSA), E. coli, and P. aeruginosa, indicated that they showed little activity compared with their Ru(ii) analogues. The results suggest that it is unfavourable for an individual metal centre with a 3+ charge to pass across the bacterial cell membrane.
Patterns of new versus recycled primary production in the terrestrial biosphere
Authors: Cleveland Cory C. , Houlton Benjamin Z. , Smith W. Kolby , Marklein Alison R. , Reed Sasha C. , Parton William , Del Grosso Stephen J. , Running Steven W.
Published: July 2013

Nitrogen (N) and phosphorus (P) availability regulate plant productivity throughout the terrestrial biosphere, influencing the patterns and magnitude of net primary production (NPP) by land plants both now and into the future. These nutrients enter ecosystems via geologic and atmospheric pathways and are recycled to varying degrees through the plant–soil–microbe system via organic matter decay processes. However, the proportion of global NPP that can be attributed to new nutrient inputs versus recycled nutrients is unresolved, as are the large-scale patterns of variation across terrestrial ecosystems. Here, we combined satellite imagery, biogeochemical modeling, and empirical observations to identify previously unrecognized patterns of new versus recycled nutrient (N and P) productivity on land. Our analysis points to tropical forests as a hotspot of new NPP fueled by new N (accounting for 45% of total new NPP globally), much higher than previous estimates from temperate and high-latitude regions. The large fraction of tropical forest NPP resulting from new N is driven by the high capacity for N fixation, although this varies considerably within this diverse biome; N deposition explains a much smaller proportion of new NPP. By contrast, the contribution of new N to primary productivity is lower outside the tropics, and worldwide, new P inputs are uniformly low relative to plant demands. These results imply that new N inputs have the greatest capacity to fuel additional NPP by terrestrial plants, whereas low P availability may ultimately constrain NPP across much of the terrestrial biosphere.
Kv7.1 ion channels require a lipid to couple voltage sensing to pore opening
Authors: Zaydman Mark A. , Silva Jonathan R. , Delaloye Kelli , Li Yang , Liang Hongwu , Larsson H. Peter , Shi Jingyi , Cui Jianmin
Published: July 2013

Voltage-gated ion channels generate dynamic ionic currents that are vital to the physiological functions of many tissues. These proteins contain separate voltage-sensing domains, which detect changes in transmembrane voltage, and pore domains, which conduct ions. Coupling of voltage sensing and pore opening is critical to the channel function and has been modeled as a protein–protein interaction between the two domains. Here, we show that coupling in Kv7.1 channels requires the lipid phosphatidylinositol 4,5-bisphosphate (PIP
2
). We found that voltage-sensing domain activation failed to open the pore in the absence of PIP
2
. This result is due to loss of coupling because PIP
2
was also required for pore opening to affect voltage-sensing domain activation. We identified a critical site for PIP
2
-dependent coupling at the interface between the voltage-sensing domain and the pore domain. This site is actually a conserved lipid-binding site among different K
+
channels, suggesting that lipids play an important role in coupling in many ion channels.
A cantilever-free approach to dot-matrix nanoprinting
Authors: Brown Keith A. , Eichelsdoerfer Daniel J. , Shim Wooyoung , Rasin Boris , Radha Boya , Liao Xing , Schmucker Abrin L. , Liu Guoliang , Mirkin Chad A.
Published: July 2013

Scanning probe lithography (SPL) is a promising candidate approach for desktop nanofabrication, but trade-offs in throughput, cost, and resolution have limited its application. The recent development of cantilever-free scanning probe arrays has allowed researchers to define nanoscale patterns in a low-cost and high-resolution format, but with the limitation that these are duplication tools where each probe in the array creates a copy of a single pattern. Here, we report a cantilever-free SPL architecture that can generate 100 nanometer-scale molecular features using a 2D array of independently actuated probes. To physically actuate a probe, local heating is used to thermally expand the elastomeric film beneath a single probe, bringing it into contact with the patterning surface. Not only is this architecture simple and scalable, but it addresses fundamental limitations of 2D SPL by allowing one to compensate for unavoidable imperfections in the system. This cantilever-free dot-matrix nanoprinting will enable the construction of surfaces with chemical functionality that is tuned across the nano- and macroscales.
Rho GTPase–independent regulation of mitotic progression by the RhoGEF Net1
Authors: Menon Sarita , Oh Wonkyung , Carr Heather S. , Frost Jeffrey A.
Published: July 2013

Neuroepithelial transforming gene 1 (Net1) is a RhoA-subfamily–specific guanine nucleotide exchange factor that is overexpressed in multiple human cancers and is required for proliferation. Molecular mechanisms underlying its role in cell proliferation are unknown. Here we show that overexpression or knockdown of Net1 causes mitotic defects. Net1 is required for chromosome congression during metaphase and generation of stable kinetochore microtubule attachments. Accordingly, inhibition of Net1 expression results in spindle assembly checkpoint activation. The ability of Net1 to control mitosis is independent of RhoA or RhoB activation, as knockdown of either GTPase does not phenocopy effects of Net1 knockdown on nuclear morphology, and effects of Net1 knockdown are effectively rescued by expression of catalytically inactive Net1. We also observe that Net1 expression is required for centrosomal activation of p21-activated kinase and its downstream kinase Aurora A, which are critical regulators of centrosome maturation and spindle assembly. These results identify Net1 as a novel regulator of mitosis and indicate that altered expression of Net1, as occurs in human cancers, may adversely affect genomic stability.
Matching with Couples: Stability and Incentives in Large Markets*
Authors: Kojima Fuhito , Pathak Parag A. , Roth Alvin E.
Published: July 2013

Accommodating couples has been a long-standing issue in the design of centralized labor market clearinghouses for doctors and psychologists, because couples view pairs of jobs as complements. A stable matching may not exist when couples are present. This article’s main result is that a stable matching exists when there are relatively few couples and preference lists are sufficiently short relative to market size. We also discuss incentives in markets with couples. We relate these theoretical results to the job market for psychologists, in which stable matchings exist for all years of the data, despite the presence of couples.
Efficacy and Safety of Rabeprazole in Children (1–11 Years) With Gastroesophageal Reflux Disease
Authors: Haddad Ibrahim , Kierkus Jaroslaw , Tron Eduardo , Ulmer April , Hu Peter , Sloan Sheldon , Silber Steven , Leitz Gerhard
Published: July 2013

Objective:

Evaluate the efficacy and safety of rabeprazole in children, 1 to 11 years old, with endoscopically/histologically proven gastroesophageal reflux disease (GERD).

Methods:

Children were randomized to 0.5‐ or 1.0‐mg/kg rabeprazole granule formulation for 12 weeks. The dose was further determined by weight: children 6 to 14.9 kg (low‐weight cohort) received 5 or 10 mg and children ≥15 kg (high‐weight cohort) received 10 or 20 mg. The primary endpoint was endoscopic/histologic healing at week 12 (defined as grade 0 on the Hetzel‐Dent classification scale and/or grade 0 on the Histological Features of Reflux Esophagitis scale).

Results:

Overall, 81% (87/108) achieved endoscopic/histologic healing at week 12 with higher healing in the low‐weight cohort (82% [5‐mg dose], 94% [10‐mg dose]) compared with high‐weight cohort (76% [10‐mg dose], 78% [20‐mg dose]). There was a significant (P < 0.001) decrease in the mean Total GERD Symptoms and Severity score from 19.7 points (baseline) to 8.6 points (week 12), with 26% fewer children reporting GERD symptoms at week 12. The average frequency of symptoms per child decreased from 7.7 (week 1) to 4.7 (week 12). The GERD Symptom Relief score showed that 71% of children felt better, 81% were rated “good to excellent” on the Global Treatment Satisfaction scale by the investigator; 77% were rated “good to excellent” on the Clinical Global Impressions‐Improvement scale by the parent/caregiver. The most common (>10%) treatment‐emergent adverse events included cough and vomiting (14% each), abdominal pain (12%), and diarrhea (11%).

Conclusions:

Rabeprazole was effective and safe in 1‐ to 11‐year‐old children with GERD.