bluuebunny/crossref_metadata_2025 huggingface dataset:
Exploring Culture: Audience Predispositions and Consequent Effects on Audience Behavior in a Mass-Gathering Setting
Authors: Hutton Alison , Brown Steve , Verdonk Naomi
Published: March 2013

Introduction

The purpose of this critical review is to look at the current literature regarding mass gatherings and to create further understanding of this area with a particular focus on what the audience brings with them to the event, particularly in a planned event with a cultural theme or focus. Through an understanding of these predispositions and consequent effects on audience behavior in a mass-gathering setting, a more complete understanding of motivation factors of crowds and audiences can also be found.

Methods

A critical review of mass-gathering literature was undertaken by searching various online academic databases. Peer-reviewed scholarly articles relevant to the cultural aspects associated with religious, sporting and music mass gatherings were also analyzed.

Results

Results from the review show that the word “culture” is often used to explain what happens at the event without reflecting how the motivations or behaviors of audiences at an event are influenced by the cultural predispositions of the audience.

Conclusions

By understanding the cultural predispositions of the audience, event planners and designers, event risk managers and event safety personnel are able to better understand the motivation of the audience and how this might impact on audience behavior at the event. Further work needs to be done, however, to investigate the broader range of predispositions. The ultimate aim of developing this understanding is to better inform the health promotion and public health messages that can be developed for a particular type of event based on the likely composition of the audience in attendance.

HuttonA, BrownS, VerdonkN. Exploring culture: audience predispositions and consequent effects on audience behavior in a mass-gathering setting. Prehosp Disaster Med. 2013;28(3):1-6.
CAN EDUCATION BE GOOD FOR BOTH GROWTH AND THE ENVIRONMENT?
Authors: Prieur Fabien , Bréchet Thierry
Published: March 2013

We develop an overlapping-generations model of growth and the environment in relation to public policy on education. Beyond the traditional mechanisms through which knowledge, growth, and the environment interplay, we stress the role played by education in environmental awareness. Assuming first that environmental awareness is constant, we show the existence of a balanced-growth path (BGP) along which environmental quality increases continually. Then, if education enhances environmental awareness, the equilibrium properties are modified: the economy can reach a steady state or converge to an asymptotic BGP. Therefore, education does not necessarily promote sustained and sustainable growth.
DYNAMIC EFFECTS OF OIL PRICE SHOCKS AND THEIR IMPACT ON THE CURRENT ACCOUNT
Authors: Schubert Stefan F.
Published: March 2013

We study the dynamic effects of an oil price shock on key economic variables and on the current account of a small open economy. We introduce time-nonseparable preferences into a standard model of a small open economy, where imported oil is used both as an intermediate input in production and as a consumption good. Using a plausible calibration of the model, we show that the changes in output and employment are quite small, and that the current account exhibits the J-curve property, both being in line with recent empirical evidence. After an oil price increase, employment falls and the current account first deteriorates. Over time, with gradually falling expenditures, the trade balance improves sufficiently to turn the current account into a surplus. The model thus provides a plausible explanation of recent empirical findings.
A LOGIC OF JUSTIFICATION AND TRUTHMAKING
Authors: GIORDANI ALESSANDRO
Published: March 2013

In the present paper we propose a system of propositional logic for reasoning about justification, truthmaking, and the connection between justifiers and truthmakers. The logic of justification and truthmaking is developed according to the fundamental ideas introduced by Artemov. Justifiers and truthmakers are treated in a similar way, exploiting the intuition that justifiers provide epistemic grounds for propositions to be considered true, while truthmakers provide ontological grounds for propositions to be true. This system of logic is then applied both for interpreting the notorious definition of knowledge as justified true belief and for advancing a new solution to Gettier counterexamples to this standard definition.
A SAHLQVIST THEOREM FOR SUBSTRUCTURAL LOGIC
Authors: SUZUKI TOMOYUKI
Published: March 2013

In this paper, we establish the first-order definability of sequents with consistent variable occurrence on bi-approximation semantics by means of the Sahlqvist–van Benthem algorithm. Then together with the canonicity results in Suzuki (2011), this allows us to establish a Sahlqvist theorem for substructural logic. Our result is not limited to substructural logic but is also easily applicable to other lattice-based logics.
Patterns of placental pathology in preterm premature rupture of membranes
Authors: Armstrong-Wells J. , Post M. D. , Donnelly M. , Manco-Johnson M. J. , Fisher B. M. , Winn V. D.
Published: March 2013

Inflammation is associated with preterm premature rupture of membranes (PPROM) and adverse neonatal outcomes. Subchorionic thrombi, with or without inflammation, may also be a significant pathological finding in PPROM. Patterns of inflammation and thrombosis may give insight into mechanisms of adverse neonatal outcomes associated with PPROM. To characterize histologic findings of placentas from pregnancies complicated by PPROM at altitude, 44 placentas were evaluated for gross and histological indicators of inflammation and thrombosis. Student's t-test (or Mann–Whitney U-test), χ2 analysis (or Fisher's exact test), mean square contingency and logistic regression were used when appropriate. The prevalence of histologic acute chorioamnionitis (HCA) was 59%. Fetal-derived inflammation (funisitis and chorionic plate vasculitis) was seen at lower frequency (30% and 45%, respectively) and not always in association with HCA. There was a trend for Hispanic women to have higher odds of funisitis (OR = 5.9; P = 0.05). Subchorionic thrombi were seen in 34% of all placentas. The odds of subchorionic thrombi without HCA was 6.3 times greater that the odds of subchorionic thrombi with HCA (P = 0.02). There was no difference in gestational age or rupture-to-delivery interval, with the presence or absence of inflammatory or thrombotic lesions. These findings suggest that PPROM is caused by or can result in fetal inflammation, placental malperfusion, or both, independent of gestational age or rupture-to-delivery interval; maternal ethnicity and altitude may contribute to these findings. Future studies focused on this constellation of PPROM placental findings, genetic polymorphisms and neonatal outcomes are needed.
Borneo in Fragments: Geology, Biota, and Contraband in Trans-national Circuits
Authors: Tagliacozzo Eric
Published: March 2013

In the second half of the nineteenth century, Borneo – supposedly one of the most isolated islands on the planet – became a trans-national site of growing importance. Instead of being imagined as a site of endless forests, inaccessible mountains, and undisturbed nature, Borneo became a place to extract and move objects, many of them spinning off into international circuits. The British and Dutch, who became the dual colonial overlords of the island, became the primary actors in facilitating these movements. Yet Asian actors – such as the Chinese, Malays, and various Dayak peoples – also were heavily involved in these transits. The first part of this essay looks at the role of geology and minerals in effecting these transitions. The second part of the paper examines the movement of biota, especiallyvis-a-visChinese networks, in connecting Borneo to other shores. Finally, the third part of the essay looks at contraband cargoes of diverse origins in also facilitating these connections. I argue that far from being an isolated and ‘off-the-beaten-track’ locale, Borneo became central to new ideas of trans-national connection in Southeast Asia, linking people, commodities, and trade circuits into an ever-tightening embrace.
Feeding requirements of white sharks may be higher than originally thought
Authors: Semmens J. M. , Payne N. L. , Huveneers C. , Sims D. W. , Bruce B. D.
Published: March 2013

Quantifying the energy requirements of animals in nature is critical for understanding physiological, behavioural and ecosystem ecology; however, for difficult-to-study species such as large sharks, prey intake rates are largely unknown. Here, we use metabolic rates derived from swimming speed estimates to suggest that feeding requirements of the world's largest predatory fish, the white shark (Carcharodon carcharias), are several times higher than previously proposed. Further, our estimates of feeding frequency identify a clear benefit in seasonal selection of pinniped colonies - a white shark foraging strategy seen across much of their range.
Moving Into the 21st Century With Therapy Documentation
Authors: Morgan Ruth
Published: March 2013

It is very important that speech-language pathologists in the school system make decisions based on evidence-based practice. Because all speech-language pathologists are responsible for collecting data, in this article I will touch on some of the differences in data collection systems with evolving technology and then focus primarily on using Google forms and spreadsheets in the school therapy setting. There are strengths and drawbacks with most of the systems.
Commercial Music: What Every SLP Should Know
Authors: Muckala Jennifer C.
Published: March 2013

In this article, I discuss the component of the commercial music field that focuses on the recording music industry and the artists participating in it. There are myriad genres of music that are involved in the business of commercial music. Technological advances are a driving force in what is considered the musical “norm” in the development of any artist. Although speech-language pathologists that treat this population are not required to have all of the answers, in this article I lay the groundwork for discussion of the challenges and strategies on how to assist this patient group best.
Robust detection of dynamic community structure in networks
Authors: Bassett Danielle S. , Porter Mason A. , Wymbs Nicholas F. , Grafton Scott T. , Carlson Jean M. , Mucha Peter J.
Published: March 2013

We describe techniques for the robust detection of community structure in some classes of time-dependent networks. Specifically, we consider the use of statistical null models for facilitating the principled identification of structural modules in semi-decomposable systems. Null models play an important role both in the optimization of quality functions such as modularity and in the subsequent assessment of the statistical validity of identified community structure. We examine the sensitivity of such methods to model parameters and show how comparisons to null models can help identify system scales. By considering a large number of optimizations, we quantify the variance of network diagnostics over optimizations (“optimization variance”) and over randomizations of network structure (“randomization variance”). Because the modularity quality function typically has a large number of nearly degenerate local optima for networks constructed using real data, we develop a method to construct representative partitions that uses a null model to correct for statistical noise in sets of partitions. To illustrate our results, we employ ensembles of time-dependent networks extracted from both nonlinear oscillators and empirical neuroscience data.
Preparation of (FexNi1−x)4N (0.5 ≤ x ≤ 0.8) compounds and evaluation of their magnetic and microwave absorbing properties
Authors: Pan Haoshuai , Cheng Xiaoqiang , Gong Chunhong , Yu Laigui , Zhang Jingwei , Zhang Zhijun
Published: March 2013

(FexNi1−x)4N (0.5 ≤ x ≤ 0.8) compounds were prepared by combining a simple reduction route with nitridation process under flowing ammonia gas at various temperatures. The microstructure as well as magnetic and microwave absorbing properties of as-prepared products was investigated. The reflection loss of (FexNi1−x)4N-paraffin composites with a filler mass fraction of 50% was calculated from permittivity and permeability, and the magnetization hysteresis loops of the composites were measured at 300 K. It has been found that the saturation magnetization value of as-prepared products increases as x rises from 0.50 to 0.80. Particularly, the reflection loss of (Fe0.67Ni0.33)4N-paraffin composite (x = 0.67) with a matching thickness of 2 mm is −17.5 dB at 12.0 GHz, lower than that of the composites with x = 0.50, 0.75, and 0.80. Moreover, (Fe0.67Ni0.33)4N-paraffin composite with a matching thickness of 2 mm has the reflection loss exceeding −10 dB in a maximum frequency range of 10.5–14.0 GHz, which is ascribed to its proper match of electromagnetic parameters and large magnetic loss. In one word, (Fe0.67Ni0.33)4N has great potential as a thin broadband microwave absorbent.
A simplified approach to calculate atomic partition functions in plasmas
Authors: D'Ammando Giuliano , Colonna Gianpiero , Capitelli Mario
Published: March 2013

A simplified method to calculate the electronic partition functions and the corresponding thermodynamic properties of atomic species is presented and applied to C(I) up to C(VI) ions. The method consists in reducing the complex structure of an atom to three lumped levels. The ground level of the lumped model describes the ground term of the real atom, while the second lumped level represents the low lying states and the last one groups all the other atomic levels. It is also shown that for the purpose of thermodynamic function calculation, the energy and the statistical weight of the upper lumped level, describing high-lying excited atomic states, can be satisfactorily approximated by an analytic hydrogenlike formula. The results of the simplified method are in good agreement with those obtained by direct summation over a complete set (i.e., including all possible terms and configurations below a given cutoff energy) of atomic energy levels. The method can be generalized to include more lumped levels in order to improve the accuracy.
Intrinsic nanofilamentation in resistive switching
Authors: Wu Xing , Cha Dongkyu , Bosman Michel , Raghavan Nagarajan , Migas Dmitri B. , Borisenko Victor E. , Zhang Xi-Xiang , Li Kun , Pey Kin-Leong
Published: March 2013

Resistive switching materials are promising candidates for nonvolatile data storage and reconfiguration of electronic applications. Intensive studies have been carried out on sandwiched metal-insulator-metal structures to achieve high density on-chip circuitry and non-volatile memory storage. Here, we provide insight into the mechanisms that govern highly reproducible controlled resistive switching via a nanofilament by using an asymmetric metal-insulator-semiconductor structure. In-situ transmission electron microscopy is used to study in real-time the physical structure and analyze the chemical composition of the nanofilament dynamically during resistive switching. Electrical stressing using an external voltage was applied by a tungsten tip to the nanosized devices having hafnium oxide (HfO2) as the insulator layer. The formation and rupture of the nanofilaments result in up to three orders of magnitude change in the current flowing through the dielectric during the switching event. Oxygen vacancies and metal atoms from the anode constitute the chemistry of the nanofilament.
X-ray irradiation of soda-lime glasses studied in situ with surface plasmon resonance spectroscopy
Authors: Serrano A. , Gálvez F. , Rodríguez de la Fuente O. , García M. A.
Published: March 2013

We present here a study of hard X-ray irradiation of soda-lime glasses performed in situ and in real time. For this purpose, we have used a Au thin film grown on glass and studied the excitation of its surface plasmon resonance (SPR) while irradiating the sample with X-rays, using a recently developed experimental setup at a synchrotron beamline [Serrano et al., Rev. Sci. Instrum. 83, 083101 (2012)]. The extreme sensitivity of the SPR to the features of the glass substrate allows probing the modifications caused by the X-rays. Irradiation induces color centers in the soda-lime glass, modifying its refractive index. Comparison of the experimental results with simulated data shows that both, the real and the imaginary parts of the refractive index of soda-lime glasses, change upon irradiation in time intervals of a few minutes. After X-ray irradiation, the effects are partially reversible. The defects responsible for these modifications are identified as non-bridging oxygen hole centers, which fade by recombination with electrons after irradiation. The kinetics of the defect formation and fading process are also studied in real time.
Liquid film drag out in the presence of molecular forces
Authors: Schmidhalter I. , Cerro R. L. , Giavedoni M. D. , Saita F. A.
Published: March 2013

From a practical as well as a conceptual point of view, one of the most interesting problems of physicochemical hydrodynamics is the drag out of a liquid film by a moving solid out of a pool of liquid. The basic problem, sometimes denoted the Landau-Levich problem [L. Landau and B. Levich, “Dragging of a liquid by a moving plate,” Acta Physicochim. USSR 17, 42–54 (1942)], involves an interesting blend of capillary and viscous forces plus a matching of the static solution for capillary rise with a numerical solution of the film evolution equation, neglecting gravity, on the downstream region of the flow field. The original solution describes experimental data for a wide range of Capillary numbers but fails to match results for large and very small Capillary numbers. Molecular level forces are introduced to create an augmented version of the film evolution equation to show the effect of van der Waals forces at the lower range of Capillary numbers. A closed form solution for static capillary rise, including molecular forces, was matched with a numerical solution of the augmented film evolution equation in the dynamic meniscus region. Molecular forces do not sensibly modify the static capillary rise region, since film thicknesses are larger than the range of influence of van der Waals forces, but are determinant in shaping the downstream dynamic meniscus of the very thin liquid films. As expected, a quantitatively different level of disjoining pressure for different values of molecular constants remains in the very thin liquid film far downstream. Computational results for a wide range of Capillary numbers and Hamaker constants show a clear transition towards a region where the film thickness becomes independent of the coating speed.
Chemically functionalized graphene for bipolar electronics
Authors: Matis Bernard R. , Bulat Felipe A. , Friedman Adam L. , Houston Brian H. , Baldwin Jeffrey W.
Published: March 2013

We report using chemical functionalization to control local carrier type and density in graphene. Low frequency transport measurements demonstrate independent carrier types and densities within adjacent graphene and hydrogenated graphene regions. Measurements of the Hall coefficient confirm that the charge carriers change sign about the charge neutrality point, that the graphene carrier density retains its linear dependence on a back gate voltage, and that the hydrogenated graphene carrier density deviates from a linear relationship. Transport measurements across the bipolar interface reveal an increasing interface resistance for higher hydrogen concentrations and a source of constant resistance for lower hydrogen concentrations.
Surface directed spinodal decomposition at TiAlN/TiN interfaces
Authors: Knutsson A. , Schramm I. C. , Asp Grönhagen K. , Mücklich F. , Odén M.
Published: March 2013

In contrast to the monolithic c-Ti1−xAlxN, the isostructural spinodal decomposition to c-AlN and c-TiN in c-Ti1−xAlxN/TiN multilayers has almost the same onset temperature for the compositions x = 0.50 and 0.66. Differential scanning calorimetry also shows that the decomposition initiates at a lower temperature compared to the monoliths with the same Al-content. Z-contrast scanning transmission electron microscopy imaging reveals a decomposed structure of the multilayers at temperatures where the monoliths remain in solid solution. In the multilayers, the decomposition is initiated at the internal interfaces. The formation of an AlN-rich layer followed by a TiN-rich area parallel to the interface in the decomposed Ti0.34Al0.66N/TiN coating, as observed in atom probe tomography, is consistent with surface directed spinodal decomposition. Phase field simulations predict this behavior both in terms of microstructure evolution and kinetics. Here, we note that surface directed spinodal decomposition is affected by the as-deposited elemental fluctuations, coherency stresses, and alloy composition.
Drifting electron excitation of acoustic phonons: Cerenkov-like effect in n-GaN
Authors: Rodrigues Clóves G. , Vasconcellos Áurea R. , Luzzi Roberto
Published: March 2013

The process of generation of acoustic phonons by way of drifting electron excitation in polar semiconductors is considered. Similarly to what is present in LO phonons, the emergence of a condensation of the pumped energy in modes around an off-center region of the Brillouin zone is evidenced. The phonons are emitted within a lobe-like distribution with an axis along the direction of the electric field. A numerical calculation for the case of GaN is done, which shows that the phenomenon can be largely enhanced at high carrier densities and in strong piezoelectric materials.
Three dimensional force detection of gold nanoparticles using backscattered light detection
Authors: Huang Lu , Guo Honglian , Li Kunlong , Chen Yuhui , Feng Baohua , Li Zhi-Yuan
Published: March 2013

We demonstrate three-dimensional position and force detection of single gold nanosphere (GNP) and gold nanorod (GNR) particles in optical trap by combining backscattered light detection and dark field imaging. The trapping stiffness of the GNPs and GNRs for all three dimensions is measured. The results show that the spring constants in the propagation direction of the trapping laser are somewhat weaker than in other two directions for GNPs. While for GNRs, the spring constants in the polarization direction of the trapping laser are a little weaker than in other two directions. The effect of trapping laser polarization on the particles yields different spring constants in the transverse plane which is perpendicular to the propagation direction. And this effect is larger on GNRs than GNPs.
Investigation of the gate oxide leakage current of low temperature formed hafnium oxide films
Authors: Verrelli E. , Tsoukalas D.
Published: March 2013

In this work, low temperature physically deposited hafnium oxide films are investigated in terms of their electrical properties through measurements and analysis of leakage currents in order to understand the defect's behavior in this dielectric material. Two extreme conditions will be presented and discussed: the first one concerns the use of a nearly trap-free hafnium oxide layer, while the second one concerns the use of a hafnium oxide film with a very large amount of electrically active traps. Particular emphasis is given to the detection and comparison of the shallow and deep traps that are responsible for the room temperature leakage of these films. It is shown that by modifying the amount of traps in the hafnium oxide layer, achieved by changing the deposition conditions, the trap's energy location is heavily influenced. The nearly trap-free sample exhibits Ohmic conduction at low fields (with activation energies in the range 16–33 meV for low temperatures and 0.13–0.14 eV for higher than ambient temperatures), Poole-Frenkel conduction at high fields (trap depth in the range 0.23–0.38 eV), while at low temperatures and high fields, the Fowler-Nordheim tunneling is identified (estimated barrier height of 1.9 eV). The charge-trap sample on the other hand exhibits Ohmic conduction at low fields (activation energies in the range 0.26–0.32 eV for higher than ambient temperatures), space charge limited current conduction at intermediate fields (exponent n = 3), while at high fields the Poole-Frenkel conduction appears (trap depth in the range 1.63–1.70 eV).
Optical bistability via dual electromagnetically induced transparency in a coupled quantum-well nanostructure
Authors: Wang Zhiping , Yu Benli
Published: March 2013

We investigate optical bistability (OB) behavior in an asymmetric three-coupled quantum well structure inside a unidirectional ring cavity. By controlling the assisting coherent driven field and the frequency detunings of the two control laser fields, we find that the appearance and disappearance of OB can easily be controlled by adjusting the positions of the dual electromagnetically induced transparency windows. Analysis in the dressed-state picture is also given. Our scheme may be used for building more efficient all-optical switches and logic-gate devices for optical computing and quantum information processing.
Investigation of the transport shortfall in Alcator C-Mod L-mode plasmas
Authors: Howard N. T. , White A. E. , Greenwald M. , Reinke M. L. , Walk J. , Holland C. , Candy J. , Görler T.
Published: March 2013

A so-called “transport shortfall,” where ion and electron heat fluxes and turbulence are underpredicted by gyrokinetic codes, has been robustly identified in DIII-D L-mode plasmas for ρ>0.55 [T. L. Rhodes et al., Nucl. Fusion 51(6), 063022 (2011); and C. Holland et al., Phys. Plasmas 16(5), 052301 (2009)]. To probe the existence of a transport shortfall across different tokamaks, a dedicated scan of auxiliary heated L-mode discharges in Alcator C-Mod are studied in detail with nonlinear gyrokinetic simulations for the first time. Two discharges, only differing by the amount of auxiliary heating are investigated using both linear and nonlinear simulation of the GYRO code [J. Candy and R. E. Waltz, J. Comput. Phys. 186, 545 (2003)]. Nonlinear gyrokinetic simulation of the low and high input power discharges reveals a discrepancy between simulation and experiment in only the electron heat flux channel of the low input power discharge. However, both discharges demonstrate excellent agreement in the ion heat flux channel, and the high input power discharge demonstrates simultaneous agreement with experiment in both the electron and ion heat flux channels. A summary of linear and nonlinear gyrokinetic results and a discussion of possible explanations for the agreement/disagreement in each heat flux channel is presented.
Note: Dynamic analysis of a robotic fish motion with a caudal fin with vertical phase differences
Authors: Yun Dongwon , Kim Kyung-Soo , Kim Soohyun , Kyung Jinho , Lee Sunghwi
Published: March 2013

In this paper, a robotic fish with a caudal fin with vertical phase differences is studied, especially focusing on the energy consumption. Energies for thrusting a conventional robotic fish and one with caudal fin with vertical phase differences are obtained and compared each other. It is shown that a robotic fish with a caudal fin with vertical phase differences can save more energy, which implies the efficient thrusting via a vertically waving caudal fin.
Chirp structure measurement of a supercontinuum pulse based on transient lens effect in tellurite glass
Authors: Zhang Hang , Zhou Zhiguang , Lin Aoxiang , Cheng Jun , Yan Lihe , Si Jinhai , Chen Feng , Hou Xun
Published: March 2013

We demonstrated the controllable acquisition of optical gated spectra from a chirped supercontinuum (SC) pulse based on ultrafast transient lens (TrL) effect. Comparing with CS2, the gated spectra had much narrower spectral bandwidths using tellurite glass (Te glass) as the nonlinear medium due to its ultrafast nonlinear response. Experimental results showed that the chirp structure of the SC pulse measured by TrL method was quite accordant with that measured by femtosecond optical Kerr gate method.
Dielectric properties of Ge2Sb2Te5 phase-change films
Authors: Prokhorov E. , Gervacio-Arciniega J. J. , Luna-Bárcenas G. , Kovalenko Y. , Espinoza-Beltrán F. J. , Trápaga G.
Published: March 2013

The static (εs) and high-frequency (ε∞) dielectric constants of amorphous and NaCl-type crystalline Ge2Sb2Te5 were measured and the relaxation effects in films were studied using impedance spectroscopy. On the basis of a simple method that allows obtaining the dielectric constant in the low resistivity planar structure, static and high frequency dielectric constants and their temperature dependencies were calculated in both phases. A surprising value of εs ≈ 750 in crystalline films was obtained, but the effective dielectric constant, εeff, estimated from the Maxwell-Wagner effective medium model, is significantly lower (εeff ≈ 34.9). Such a high value of εs obtained by electrical impedance measurements has been explained by Maxwell-Wagner relaxation, the separation of charges at the interface between grains and grain boundaries. Additionally, three relaxation processes (alpha, beta, and Ohmic relaxation) were observed in the amorphous phase and four relaxations (dipolar relaxation of grains, Ohmic relaxation of grains, dipolar relaxation of grain boundaries, and Maxwell-Wagner relaxation) were observed in the crystalline phase. From these results, a new rule for the selection of materials for optical phase-change data storage is proposed: polycrystalline films must have a high volume fraction of grain boundaries. This requirement increases the effective dielectric constant and the reflectance contrast between amorphous and crystalline phases.
Giant magnetoelectric effect in mechanically mediated composite structure of TbFe2 alloy and Pb(Zr,Ti)O3 ceramics
Authors: Bi K. , Zhou J. , Wu W. , Hong H.
Published: March 2013

Magnetoelectric (ME) effect has been studied in a simple composite structure made up of TbFe2 and Pb(Zr,Ti)O3. The working principal has also been analyzed. The ME coupling is achieved by end bonding instead of interface bonding. The influence of the bias magnetic field and the magnetic field frequency on ME coupling is discussed. The ME voltage coefficient depends strongly on the piezomagnetic coupling. The ME voltage coefficient and resonance frequencies for these composites are influenced by structural parameters. A large ME voltage coefficient as high as 14.1 V cm−1 Oe−1 is obtained. The large ME coefficient makes these structures possible for applications in sensors, actuators, and transducers.
Investigation of skutterudite MgyCo4Sb12: High pressure synthesis and thermoelectric properties
Authors: Yang Jianqing , Zhang Long , Liu Yadi , Chen Chen , Li Jianghua , Yu Dongli , He Julong , Liu Zhongyuan , Tian Yongjun , Xu Bo
Published: March 2013

The filling behavior of Mg atoms into CoSb3 lattice voids under pressure was investigated theoretically, revealing ambient-pressure-inaccessible Mg-filled CoSb3 can be stabilized under high pressure. Inspired by this result, we synthesized Mg-filled CoSb3 using high pressure synthesis. The synthetic samples show Im3¯ symmetry of skutterudite structure, with Mg filling fraction as high as 0.4. Thermoelectric measurements indicated a significant reduction in thermal conductivity and a limited enhancement of power factor after Mg filling, which may connect with the relatively high electronegativity of Mg. The highest ZT of 0.33 was achieved in Mg0.4Co4Sb12 at 620 K. Compared with the traditional solid state reaction method, high pressure synthesis can substantially shorten the reaction duration and extend fillable elements, thus providing us an effective pathway for thermoelectric materials fabrication.
Model of the boundary layer of a vacuum-arc magnetic filter
Authors: Minotti F. , Giuliani L. , Grondona D. , Della Torre H. , Kelly H.
Published: March 2013

A model is developed to describe the electrostatic boundary layer in a positively biased magnetic filter in filtered arcs with low collisionality. The set of equations used includes the electron momentum equation, with an anomalous collision term due to micro-instabilities leading to Bohm diffusion, electron mass conservation, and Poisson equation. Analytical solutions are obtained, valid for the regimes of interest, leading to an explicit expression to determine the electron density current to the filter wall as a function of the potential of the filter and the ratio of electron density at the plasma to that at the filter wall. Using a set of planar and cylindrical probes it is verified experimentally that the mentioned ratio of electron densities remains reasonably constant for different magnetic field values and probe bias, which allows to obtain a closed expression for the current. Comparisons are made with the experimentally determined current collected at different sections of a positively biased straight filter.
P-type InGaN across the entire alloy composition range
Authors: Wang K. , Araki T. , Yu K. M. , Katsuki T. , Mayer M. A. , Alarcon-Llado E. , Ager J. W. , Walukiewicz W. , Nanishi Y.
Published: March 2013

A systematic investigation on Mg doped and undoped InGaN epilayers grown by plasma-assisted molecular beam epitaxy has been conducted. Single phase InGaN alloys across the entire composition range were synthesized and Mg was doped into InxGa1−xN (0.1 ≤ x ≤ 0.88) epilayers up to ∼1020/cm3. Hall effect, thermopower, and electrochemical capacitance voltage experimental results demonstrate the realization of p-type InGaN across the entire alloy composition range for properly Mg doped InGaN. Hole densities have been measured or estimated to be in the lower ∼1018/cm3 range when the net acceptor concentrations are in the lower ∼1019/cm3 range across the composition range.
First observation of magnetoelectric effect in M-type hexaferrite thin films
Authors: Mohebbi Marjan , Ebnabbasi Khabat , Vittoria Carmine
Published: March 2013

The magnetoelectric (ME) effect in M-type hexaferrite thin films is reported. Prior to this work, the ME effect in hexaferrite materials was observed only in bulk polycrystalline materials. Thin films of SrCo2Ti2Fe8O19 were grown on sapphire (0001) using pulsed laser deposition. The thin films were characterized by X-ray diffractometer, scanning electron microscope, energy-dispersive spectroscopy, vibrating sample magnetometer, and ferromagnetic resonance. We measured saturation magnetization of 1250 G, g-factor of 2.66, and coercive field of 20 Oe for these magnetoelectric M-type hexaferrite thin films. The magnetoelectric effect was confirmed by monitoring the change rate in remanence magnetization with the application of DC voltage at room temperature and it gave rise to changes in remanence in the order of 12.8% with the application of only 1 V (DC voltage). We deduced a magnetoelectric coupling, α, of 6.07 × 10−9 s m–1 in SrCo2Ti2Fe8O19 thin films.
All-optically induced currents resulting from frequency-modulated coherent polarization
Authors: Priyadarshi Shekhar , Pierz Klaus , Bieler Mark
Published: March 2013

We employ polarization-shaped ultrafast optical pulses to generate photocurrents, which only arise if the optically induced coherent polarization is frequency modulated. This frequency modulation is obtained via detuned excitation of light-hole excitons in (110)-oriented GaAs quantum wells. The observed photocurrents vanish for resonant excitation of excitons and reverse their direction with a change of the sign of detuning. Moreover, the currents do not exist for continuous-wave excitation. Our work reveals the existence of a new class of photocurrents and visualizes the complexity of current response tensors. This is helpful for the better understanding of optically induced microscopic transport in semiconductors.
Effect of magnetic fluctuations on the confinement and dynamics of runaway electrons in the HT-7 tokamak
Authors: Zhou R. J. , Hu L. Q. , Li E. Z. , Xu M. , Zhong G. Q. , Xu L. Q. , Lin S. Y.
Published: March 2013

The nature of runaway electrons is such that the confinement and dynamics of the electrons can be strongly affected by magnetic fluctuations in plasma. Experimental results in the HT-7 tokamak indicated significant losses of runaway electrons due to magnetic fluctuations, but the loss processes did not only rely on the fluctuation amplitude. Efficient radial runaway transport required that there were no more than small regions of the plasma volume in which there was very low transport of runaways. A radial runaway diffusion coefficient of Dr≈10 m2s-1 was derived for the loss processes, and diffusion coefficient near the resonant magnetic surfaces and shielding factor ϒ=0.8 were deduced. Test particle equations were used to analyze the effect of magnetic fluctuations on runaway dynamics. It was found that the maximum energy that runaways can gain is very sensitive to the value of αs (i.e., the fraction of plasma volume with reduced transport). αs=(0.28−0.33) was found for the loss processes in the experiment, and maximum runaway energy could be controlled in the range of E=(4 MeV-6 MeV) in this case. Additionally, to control the maximum runaway energy below 5 MeV, the normalized electric field needed to be under a critical value Dα=6.8, and the amplitude normalized magnetic fluctuations b̃ needed to be at least of the order of b̃≈3×10−5.
Electrical properties of thermoelectric cobalt Ca3Co4O9 epitaxial heterostructures
Authors: Guo Haizhong , Wang Shufang , Wang Le , Jin Kui-juan , Chen Shanshan , Fu Guangsheng , Ge Chen , Lu Huibin , Wang Can , He Meng , Yang Guozhen
Published: March 2013

Heterostructures fabricated from layered cobalt oxides offer substantial advantages for thermoelectric applications. C-axis-oriented Ca3Co4O9 (CCO) thin films on SrTiO3 substrates and Ca3Co4O9/SrTi0.993Nb0.007O3 p-n heterojunctions were fabricated by pulsed laser deposition. The measurements of in-plane resistivity, thermopower, and magnetic properties performed on the Ca3Co4O9 thin films were found to be comparable to ab-plane those of the single crystals due to good orientation of the films. The temperature dependence of the electrical transport properties of Ca3Co4O9/SrTi0.993Nb0.007O3 p-n heterojunction was also investigated. The junction shows two distinctive transport mechanisms at different temperature regimes under forward bias: tunneling across the Schottky barrier in the temperature range of 100-380 K, and tunneling mechanism at low bias and thermal emission mechanism at high bias between 10 and 100 K. However, for the case of low reverse bias, the trap assisted tunneling process should be considered for the leakage current. Negative magnetoresistance effect is observed at low temperatures, related to the electron spin-dependent scattering and the interface resistance of the heterostructures.
Roles of hydrogenation, annealing and field in the structure and magnetic entropy change of Tb-based bulk metallic glasses
Authors: Luo Qiang , Schwarz Björn , Mattern Norbert , Shen Jun , Eckert Jürgen
Published: March 2013

The reduction of open-volume regions in Tb-based metallic glass (MG) by annealing and hydrogen charging was found to rearrange the atomic structure and tune the magnetic behaviors. After crystallization, the magnetic structure and magnetic entropy change (MEC) alters due to the structural transformation, and a plateau-like-MEC behavior can be obtained. The hydrogen concentration after charging at 1mA/cm2 for 576 h reaches as high as 3290 w-ppm. The magnetization behavior and the MEC change due to the modification of the exchange interaction and the random magnetic anisotropy (RMA) upon hydrogenation. At low temperatures, irreversible positive MEC was obtained, which is related to the internal entropy production. The RMA-to-exchange ratio acts as a switch to control the irreversible entropy production channel and the reversible entropy transfer channel. The field dependence of the MEC is discussed in term of the competition among Zeeman energy, exchange interaction and RMA.
Evaluating spectral indices and spectral mixture analysis for assessing fire severity, combustion completeness and carbon emissions
Authors: Veraverbeke Sander , Hook Simon J.
Published: March 2013

We used a Landsat Thematic Mapper (TM) image from the 2011 Wallow fire in Arizona, USA, in combination with field data to assess different methods for determining fire severity. These include the normalised burn ratio (NBR), the differenced NBR (dNBR), the relative dNBR (RdNBR) and the burned fraction (BF) estimated by spectral mixture analysis (SMA). The Geo Composite Burn Index (GeoCBI) and vegetation mortality data were used as ground truth. Of all the remotely sensed measures evaluated the dNBR had the best performance (GeoCBI–dNBR R2=0.84), which supports the operational use of the dNBR for post-fire management. Of the other remotely sensed measures, the SMA-derived BF also had moderately high correlations with the GeoCBI (R2=0.66). Both approaches demonstrated their usefulness for refining modelled CC values, however, the SMA approach has the advantage of providing transferable quantitative estimates without the need for calibration with field data. The carbon emission estimates that included fire severity were more than 50% lower than the estimate derived from modelling alone. These results suggest that for certain fire types, especially mixed-severity fires, current emission estimates are significantly overestimated, which will affect global carbon emission estimates from wildfires.
An algorithmic approach for breakage-fusion-bridge detection in tumor genomes
Authors: Zakov Shay , Kinsella Marcus , Bafna Vineet
Published: March 2013

Breakage-fusion-bridge (BFB) is a mechanism of genomic instability characterized by the joining and subsequent tearing apart of sister chromatids. When this process is repeated during multiple rounds of cell division, it leads to patterns of copy number increases of chromosomal segments as well as fold-back inversions where duplicated segments are arranged head-to-head. These structural variations can then drive tumorigenesis. BFB can be observed in progress using cytogenetic techniques, but generally BFB must be inferred from data such as microarrays or sequencing collected after BFB has ceased. Making correct inferences from this data is not straightforward, particularly given the complexity of some cancer genomes and BFB’s ability to generate a wide range of rearrangement patterns. Here we present algorithms to aid the interpretation of evidence for BFB. We first pose the BFB count-vector problem: given a chromosome segmentation and segment copy numbers, decide whether BFB can yield a chromosome with the given segment counts. We present a linear time algorithm for the problem, in contrast to a previous exponential time algorithm. We then combine this algorithm with fold-back inversions to develop tests for BFB. We show that, contingent on assumptions about cancer genome evolution, count vectors and fold-back inversions are sufficient evidence for detecting BFB. We apply the presented techniques to paired-end sequencing data from pancreatic tumors and confirm a previous finding of BFB as well as identify a chromosomal region likely rearranged by BFB cycles, demonstrating the practicality of our approach.
Primary aldosteronism and impaired natriuresis in mice underexpressing TGFβ1
Authors: Kakoki Masao , Pochynyuk Oleh M. , Hathaway Catherine M. , Tomita Hirofumi , Hagaman John R. , Kim Hyung-Suk , Zaika Oleg L. , Mamenko Mykola , Kayashima Yukako , Matsuki Kota , Hiller Sylvia , Li Feng , Xu Longquan , Grant Ruriko , Bertorello Alejandro M. , Smithies Oliver
Published: March 2013

To uncover the potential cardiovascular effects of human polymorphisms influencing transforming growth factor β1 (TGFβ1) expression, we generated mice with
Tgfb1
mRNA expression graded in five steps from 10% to 300% normal. Adrenal expression of the genes for mineralocorticoid-producing enzymes ranged from 50% normal in the hypermorphs at age 12 wk to 400% normal in the hypomorphs accompanied with proportionate changes in plasma aldosterone levels, whereas plasma volumes ranged from 50% to 150% normal accompanied by marked compensatory changes in plasma angiotensin II and renin levels. The aldosterone/renin ratio ranged from 0.3 times normal in the 300% hypermorphs to six times in the 10% hypomorphs, which have elevated blood pressure. Urinary output of water and electrolytes are markedly decreased in the 10% hypomorphs without significant change in the glomerular filtration rate. Renal activities for the Na
+
, K
+
-ATPase, and epithelial sodium channel are markedly increased in the 10% hypomorphs. The hypertension in the 10% hypomorphs is corrected by spironolactone or amiloride at doses that do not change blood pressure in wild-type mice. Thus, changes in
Tgfb1
expression cause marked progressive changes in multiple systems that regulate blood pressure and fluid homeostasis, with the major effects being mediated by changes in adrenocortical function.
Vps35 loss promotes hyperresorptive osteoclastogenesis and osteoporosis via sustained RANKL signaling
Authors: Xia Wen-Fang , Tang Fu-Lei , Xiong Lei , Xiong Shan , Jung Ji-Ung , Lee Dae-Hoon , Li Xing-Sheng , Feng Xu , Mei Lin , Xiong Wen-Cheng
Published: March 2013

Receptor activator of NF-κB (RANK) plays a critical role in osteoclastogenesis, an essential process for the initiation of bone remodeling to maintain healthy bone mass and structure. Although the signaling and function of RANK have been investigated extensively, much less is known about the negative regulatory mechanisms of its signaling. We demonstrate in this paper that RANK trafficking, signaling, and function are regulated by VPS35, a major component of the retromer essential for selective endosome to Golgi retrieval of membrane proteins. VPS35 loss of function altered RANK ligand (RANKL)–induced RANK distribution, enhanced RANKL sensitivity, sustained RANKL signaling, and increased hyperresorptive osteoclast (OC) formation. Hemizygous deletion of the Vps35 gene in mice promoted hyperresorptive osteoclastogenesis, decreased bone formation, and caused a subsequent osteoporotic deficit, including decreased trabecular bone volumes and reduced trabecular thickness and density in long bones. These results indicate that VPS35 critically deregulates RANK signaling, thus restraining increased formation of hyperresorptive OCs and preventing osteoporotic deficits.
The Endophytic Lifestyle of Escherichia coli O157:H7: Quantification and Internal Localization in Roots
Authors: Wright Kathryn M. , Chapman Sean , McGeachy Kara , Humphris Sonia , Campbell Emma , Toth Ian K. , Holden Nicola J.
Published: March 2013

The foodborne pathogen Escherichia coli O157:H7 is increasingly associated with fresh produce (fruit and vegetables). Bacterial colonization of fresh produce plants can occur to high levels on the external tissue but bacteria have also been detected within plant tissue. However, questions remain about the extent of internalization, its molecular basis, and internal location of the bacteria. We have determined the extent of internalization of E. coli O157:H7 in live spinach and lettuce plants and used high-resolution microscopy to examine colony formation in roots and pathways to internalization. E. coli O157:H7 was found within internal tissue of both produce species. Colonization occurred within the apoplast between plant cells. Furthermore, colonies were detected inside the cell wall of epidermal and cortical cells of spinach and Nicotiana benthamiana roots. Internal colonization of epidermal cells resembled that of the phytopathogen Pectobacterium atrosepticum on potato. In contrast, only sporadic cells of the laboratory strain of E. coli K-12 were found on spinach, with no internal bacteria evident. The data extend previous findings that internal colonization of plants appears to be limited to a specific group of plant-interacting bacteria, including E. coli O157:H7, and demonstrates its ability to invade the cells of living plants.