bluuebunny/crossref_metadata_2025 huggingface dataset:
Linear and non-linear propagation of electrostatic positron-acoustic waves and envelope solitons in 4-component quantum plasma containing relativistically degenerate electrons and positrons
Authors: Ahmad Rashid , Gul Nabi , Adnan Muhammad , Tribeche Mouloud , Khattak Fida Younus
Published: April 2017

A hydrodynamic model is employed to investigate the linear and non-linear propagation of electrostatic positron acoustic waves (EPAWs) in a 4-component relativistic-degenerate electron-positron-ion plasma. The plasma constituents are cold positrons, hot relativistic-degenerate electrons and positrons, and cold static ions in the background. The hot electrons and positrons are treated as inertialess, and the cold positrons provide the inertia while the restoring force comes from the hot species. A dispersion relation for low-frequency EPAWs is derived. It is observed that an increase in the relative density of hot positrons to cold positrons and relativistic effects tend to reduce the speed of the EPAWs. Employing the standard Reductive Perturbation Technique, a Korteweg de Vries (KdV)-type equation is derived, and the existence of KdV solitons is demonstrated. In this case, an increase in the relative density of hot to cold positrons and relativistic effects decreases both the amplitude and width of the solitons. Furthermore, a Non-Linear Schrödinger (NLS) equation is also derived. The variation in the group velocity shows less change with the wavenumber for the higher concentration of positrons and also with the stronger relativistic effects. The interchange in the behaviour of group velocity with the positron concentration is observed for values k > 1. The growth rate of modulation instability is derived, and its dependence on the positron concentration and relativistic effects are discussed. The relativistic effects reduce the stability region while the growth rate is enhanced while moving from weak-relativistic to ultra-relativistic cases. The hot positron concentration makes the wave modulationally stable for an extended region of the wavenumber k. The solution of the NLS equation admits the existence of both bright and dark envelope solitons. The profiles of the envelope solitons show inverse dependence on the positron concentration and on the relativistic effects.
Study of plasma current effect on divertor power footprint widths through experiments and modeling in EAST L-mode plasmas
Authors: Deng G. Z. , Liu X. J. , Wang L. , Liu S. C. , Chen L. , Zhang H. , Xu J. C. , Feng W. , Liu J. B. , Liu H. , Gao X.
Published: April 2017

Integrated studies of the scaling of divertor power footprint widths with plasma current in Experimental Advanced Superconducting Tokamak (EAST) L-mode plasmas are carried out through experiments and modeling. The divertor power widths, which consist of the scrape-off layer power decay length λq and the heat spreading S, are calculated from the measurements of divertor Langmuir probes (div-LPs) and scrape-off layer plasma simulation (SOLPS). A strong inverse scaling of both λq (mm) and S (mm) from the div-LP with plasma current Ip (MA) is demonstrated, with the regressions being λq=4.37Ip−1.04±0.075 and S=2.31Ip−0.997±0.047. However, a much weaker inverse scaling of λq with Ip is shown by the measurement of outer mid-plane reciprocating probes, which gives λq,RP=6.56Ip−0.31±0.056. It indicates that the connection length may have played a stronger role in the negative scaling of λq with Ip than radial transport. A similar conclusion can also be drawn from a comparison of the simulation of the plasma current scan with a set of fixed radial transport and another set of coefficient modified by Ip. This indicates that plasma configuration with a longer connection length is a better L-mode operational scenario for diverted tokamaks.
Terahertz quantum cascade laser with an X-valley-based injector
Authors: Roy Mithun , Talukder Muhammad Anisuzzaman
Published: April 2017

We present a novel terahertz (THz) quantum cascade laser (QCL) design where Γ-valley states are used for lasing transition and X-valley states—in particular, Xz-states—are used as injector subbands. Since the lasing states in our proposed structure are populated and depopulated mainly through the interface roughness assisted Γ-Xz electron scattering, we present a model to describe this intervalley carrier transport. In the injector region of the proposed THz QCL, we use a quaternary AlGaAsP material to introduce tensile strain, which plays a crucial role in increasing the gain. To compensate the strain per period, we propose to grow the periodic heterostructure on a GaAs0.94P0.06 virtual substrate. To simulate the carrier transport and hence calculate the gain and lasing performance of the proposed THz QCL, we use a simplified density matrix formalism that considers resonant tunneling, dephasing, and the important intersubband scattering mechanisms. Since electron temperature significantly varies from lattice temperature for QCLs, we take their difference into account using the kinetic energy balance method. We show that the proposed structure is capable of lasing up to a maximum lattice temperature of ∼119 K at 4.8 THz. For future improvements of the device, we identify major performance-degrading factors of the proposed design.
Optimizing thermochromic VO2 by co-doping with W and Sr for smart window applications
Authors: Dietrich Marc K. , Kuhl Florian , Polity Angelika , Klar Peter J.
Published: April 2017

Smart windows possess the potential to contribute significantly to reducing the world-wide energy consumption in the future. The properties of the thermochromic metal oxide VO2 are closest to the material requirements set by economic considerations for the use as an active layer in thermochromic glazings. We show that the required parameters can be achieved by modifying VO2 on the atomic level, i.e., by simultaneous co-doping with Sr and W on the cation site. In particular, the transition temperature ϑc can be adjusted in the range between 15 and 68 °C by varying W contents, whereas the incorporation of Sr mainly increases the band gap yielding a greyish color of the films. Interestingly, the simultaneous presence of W and Sr enhances both effects. The co-doping leads to values of the luminous transmittance Tlum and the solar transmittance Tsol fulfilling the requirements set by application. The variation of the solar transmittance ΔTsol of the plain thin films on a glass substrate already is larger than 5% for all samples promising that the required value of ΔTsol=10% is achievable by using such thin films as part of an optically engineered multilayer system.
On the c-Si/SiO2 interface recombination parameters from photo-conductance decay measurements
Authors: Bonilla Ruy S. , Wilshaw Peter R.
Published: April 2017

The recombination of electric charge carriers at semiconductor surfaces continues to be a limiting factor in achieving high performance optoelectronic devices, including solar cells, laser diodes, and photodetectors. The theoretical model and a solution algorithm for surface recombination have been previously reported. However, their successful application to experimental data for a wide range of both minority excess carrier concentrations and dielectric fixed charge densities has not previously been shown. Here, a parametrisation for the semiconductor-dielectric interface charge Qit is used in a Shockley-Read-Hall extended formalism to describe recombination at the c-Si/SiO2 interface, and estimate the physical parameters relating to the interface trap density  Dit, and the electron and hole capture cross-sections σn and σp. This approach gives an excellent description of the experimental data without the need to invoke a surface damage region in the c-Si/SiO2 system. Band-gap tail states have been observed to limit strongly the effectiveness of field effect passivation. This approach provides a methodology to determine interface recombination parameters in any semiconductor-insulator system using macro scale measuring techniques.
Graphical analysis of current-voltage characteristics in memristive interfaces
Authors: Acha C.
Published: April 2017

A graphical representation of current-voltage (IV) measurements of typical memristive interfaces at constant temperature is presented. This is the starting point to extract relevant microscopic information of the parameters that control the electrical properties of a device based on a particular metal-oxide interface. The convenience of the method is illustrated presenting some examples where the IV characteristics were simulated in order to gain insight into the influence of the fitting parameters.
Interplay of delay and multiplexing: Impact on cluster synchronization
Authors: Singh Aradhana , Jalan Sarika , Boccaletti Stefano
Published: April 2017

Communication delays and multiplexing are ubiquitous features of real-world network systems. We here introduce a simple model where these two features are simultaneously present and report the rich phenomenology which is actually due to their interplay on cluster synchronization. A delay in one layer has non trivial impacts on the collective dynamics of the other layers, enhancing or suppressing synchronization. At the same time, multiplexing may also enhance cluster synchronization of delayed layers. We elucidate several nontrivial (and anti-intuitive) scenarios, which are of interest and potential application in various real-world systems, where the introduction of a delay may render synchronization of a layer robust against changes in the properties of the other layers.
A dry process for forming ultrathin silicon oxide film on gold nanoparticle
Authors: Akita Atsunobu , Fujiwara Keigo , Fujishima Musashi , Tada Hiroaki
Published: April 2017

A simple dry process for preparing an ultrathin SiO2 shell on gold nanoparticle (Au NP) has been developed. The adsorption and reaction of 1,3,5,7-tetramethylcyclotetrasiloxane on Au NP-loaded ZnO (Au/ZnO) from gas phase at 353 K yields a multilayer of polymethylsiloxane (PMS) on the Au surface, while a monolayer is formed on the ZnO surface. The postheating in the air at 773 K transforms the PMS layer to a uniform SiO2 layer with thickness (lSiO2) of ∼2 nm on the surface of every Au NP (Au@SiO2/ZnO). UV-visible absorption spectra show that the SiO2 shell enhances the localized surface plasmon resonance of Au NP with its peak redshifted from 530 nm to 571 nm. The 3D finite-difference time-domain calculations for Au@SiO2(lSiO2 = 2 nm)/ZnO indicate that a strong local electric field is generated at the Au-SiO2-ZnO three-phase interface along the peripheral edge of Au NP with an enhancement factor of ∼107.
Double Dirac cone in two-dimensional phononic crystals beyond circular cells
Authors: Dai Hongqing , Liu Tingting , Jiao Junrui , Xia Baizhan , Yu Dejie
Published: April 2017

A double Dirac cone plays a significant role in the design of zero-refractive-index metamaterials without phase variation and topological insulators with pseudospin states. We present a study on the formation of a double Dirac cone in two-dimensional phononic crystals consisting of either hexagonal or triangular columns in air. We arranged hexagonal and triangular columns separately in a honeycomb lattice to explore the influence of phononic crystal symmetry on the formation of the double Dirac cone. The results show that phononic crystals forming a honeycomb lattice with C6v or C6 symmetry induce an accidental degeneracy, but C3v and C3 cannot. We also demonstrate that by varying the filling ratio of the hexagonal columns, a topological phase transformation induced by energy band inversion with dipolar and quadrupolar states occurs near the double Dirac cone. Transmission properties for acoustic tunneling and waveform shaping are confirmed in two numerical simulation examples. A discussion is given on the formation of the double Dirac cone in different phononic crystal symmetries in a honeycomb lattice. The conclusions suggest a new route for designing topological and zero-refractive-index acoustic devices.
Structural and electrical transport properties of La2Mo2O9 thin films prepared by pulsed laser deposition
Authors: Paul T. , Ghosh A.
Published: April 2017

We have studied the structure and electrical properties of La2Mo2O9 thin films of different thicknesses prepared by the laser deposition technique at different substrate temperatures. The structural properties of the thin films have been investigated using XRD, XPS, AFM, TEM, SEM, and Raman spectroscopy. The electrical transport properties of the thin films have been investigated in wide temperature and frequency ranges. The cubic nature of the thin films has been confirmed from structural analysis. An enhancement of the oxygen ion conductivity of the films up to five orders of magnitude is obtained compared to that of the bulk La2Mo2O9, suggesting usefulness of the thin films as electrolytes in micro-solid oxide fuel cells. The enhanced dc ionic conductivity of the thin films has been interpreted using the rule of the mixture model, while a power law model has been used to investigate the frequency and temperature dependences of the conductivity. The analysis of the results predicts the three-dimensional oxygen ion conduction in the thin films.
Variable stiffness Fe82Ga13.5Al4.5 spring based on magnetoelastic effect
Authors: Li Mingming , Li Jiheng , Bao Xiaoqian , Liu Yangyang , Wang Jiquan , Zhao Yalong , Gao Xuexu
Published: April 2017

The elastic modulus of magnetostriction materials can be controlled in real time by changing the magnetic field. Accordingly, spring with variable stiffness coefficients is available. In this work, Fe82Ga13.5Al4.5 wires of 3.5 mm diameter were prepared by heat forging, rolling, and drawing. Holding at 600 °C for 30 min after annealing at 1100 °C significantly improved the magnetostriction and soft magnetic properties of drawn wires. The tensile test shows two types of relative strain at the initial stage of tension: the elastic modulus under the condition of unsaturated magnetized (Ea) and purely mechanical elastic modulus (Es). The modulus defect ((Es−Ea)/Es × 100%) due to the additional magnetoelastic strain is up to 41.6%. Then, Fe82Ga13.5Al4.5 spring and the loading way of the magnetic field were designed and processed. By tuning the magnetic field strength, the stiffness coefficient of the spring is controlled accordingly. An apparent change in the stiffness coefficient of 10.86% is observed by further increasing the magnetic field to 235.5 Oe, which shows good prospect in a range of technical applications, such as force sensors and suspension systems.
Nonlinear friction dynamics on polymer surface under accelerated movement
Authors: Aita Yuuki , Asanuma Natsumi , Takahashi Akira , Mayama Hiroyuki , Nonomura Yoshimune
Published: April 2017

Nonlinear phenomena on the soft material surface are one of the most exciting topics of chemical physics. However, only a few reports exist on the friction phenomena under accelerated movement, because friction between two solid surfaces is considered a linear phenomenon in many cases. We aim to investigate how nonlinear accelerated motion affects friction on solid surfaces. In the present study, we evaluate the frictional forces between two polytetrafluoroethylene (PTFE) resins using an advanced friction evaluation system. On PTFE surfaces, the normalized delay time δ, which is the time lag in the response of the friction force to the accelerated movement, is observed in the pre-sliding friction process. Under high-velocity conditions, kinetic friction increases with velocity. Based on these experimental results, we propose a two-phase nonlinear model including a pre-sliding process (from the beginning of sliding of a contact probe to the establishment of static friction) and a kinetic friction process. The present model consists of several factors including velocity, acceleration, stiffness, viscosity, and vertical force. The findings reflecting the viscoelastic properties of soft material is useful for various fields such as in the fabrication of clothes, cosmetics, automotive materials, and virtual reality systems as well as for understanding friction phenomena on soft material surfaces.
Destabilization of toroidal Alfvén eigenmode during neutral beam injection heating on HL-2A
Authors: Shi P. W. , Chen W. , Shi Z. B. , Duan X. R. , Yu L. M. , Zhong W. L. , Jiang M. , Yang Z. C. , Li J. X. , Wen J. , Ding X. T. , Liu Yi. , Yang Q. W. ,   HL-2A Team
Published: April 2017

Toroidal Alfvén eigenmodes (TAEs) driven by fast ions during neutral beam injection heating have been observed on HL-2A. TAEs are found to be excited by the sideband resonance between fast ions and shear Alfvén waves. Their frequencies range from 90 kHz to 200 kHz, and toroidal mode numbers of the most unstable TAEs are n = 1–3. Nonlinear behaviours of TAEs, such as frequency chirping, pitch-fork splitting, and nonlinear mode-mode coupling, are also excited. In the down-chirping case, TAEs show typical ballooning mode structures and their amplitudes are around δBr = 3.25 × 10−4T at the edge of the plasma. The mode frequency is proportional to the square of time, i.e., f(t) ∼ t1∕2, which agrees well with the theoretical prediction. Pitch-fork splitting of TAEs has also been excited on HL-2A, and their growth rate is about γl ∼ 0.22 × 104 s−1. TAE coupling with a tearing mode results in the appearances of series of Alfvénic modes (AMs). The two AMs, which have the same absolute mode number but rotate in different diamagnetic drift directions, couple together and lead to the generation of a high frequency mode with a toroidal mode number of n = 0. The experimental results also indicate that nonlinear mode-mode coupling degenerates the confinement of fast ions.
Thermal resistance of twist boundaries in silicon nanowires by nonequilibrium molecular dynamics
Authors: Bohrer Jan K. , Schröer Kevin , Brendel Lothar , Wolf Dietrich E.
Published: April 2017

The thermal boundary resistance (Kapitza resistance) of (001) twist boundaries in silicon is investigated by nonequilibrium molecular dynamics simulations. In order to enable continuous adjustment of the mismatch angle, a cylindrical geometry with fixed atomic positions at the boundaries is devised. The influence of the boundary conditions on the Kapitza resistance is removed by means of a finite size analysis. Due to the diamond structure of silicon, twist boundaries with mismatch angles ϕ and 90°−ϕ are not equivalent, whereas those with ±ϕ or with 90°±ϕ are. The Kapitza resistance increases with mismatch angle up to 45°, where it reaches a plateau around 1.56±0.05Km2/GW. Between 80° and the 90°Σ1 grain boundary it drops by about 30%. Surprisingly, lattice coincidence at other angles (Σ5,Σ13,Σ27,Σ25) has no noticable effect on the Kapitza resistance. However, there is a clear correlation between the Kapitza resistance and the width of a non-crystalline layer at the twist boundaries.
Synthesis of Self-Assembled Co3O4 Nanoparticles with Porous Sea Urchin-Like Morphology and their Catalytic and Electrochemical Applications
Authors: Jamil Saba , Janjua Muhammad Ramzan Saeed Ashraf , Khan Shanza Rauf
Published: April 2017

Novel self-assembled cobalt oxide nanoparticles with sea urchin-like morphology were synthesized using a solvothermal method. It was observed that the product consists of a tube-like arrangement of nanoparticles arising from a base. The base is formed by the arrangement of nanoparticles in the form of dense aggregates. A series of comparative experiments were performed over different time intervals to investigate the mechanism of formation of this morphology. The electrochemical performance of an electrode prepared based on this product was analysed by cyclic voltammetry, chronopotentiometry, and alternating current impedance. The electrochemical study shows that the prepared electrode possesses high capacitance and offers very low resistance against the flow of electrons. The product was used as a catalyst for the reduction of nitrobenzene in aqueous medium. The value of the apparent rate constant of catalysis was found to be as high as previously reported values.
Contrasting patterns of residency and space use of coastal sharks within a communal shark nursery
Authors: Oh Beverly Z. L. , Thums Michele , Babcock Russ C. , Meeuwig Jessica J. , Pillans Richard D. , Speed Conrad , Meekan Mark G.
Published: April 2017

The benefits of marine protected areas are difficult to estimate for mobile species, but their effectiveness can be increased if essential habitats, such as nursery areas, are protected. In the present study we examined movements of juvenile blacktip reef (Carcharhinus melanopterus) and sicklefin lemon (Negaprion acutidens) sharks in a coastal nursery in northern Australia. Telemetry-derived data were modelled using Brownian bridges and overlaid with maps of habitats and no-take zones. Juvenile N. acutidens were typically residents (≥30 days) of the nursery with small areas of core space use (<1.9km2), whereas juvenile C. melanopterus were non-residents (<30 days) and used larger areas (<5.6km2). Both species exhibited positive selection for sandflats and mangroves, and avoidance of deeper lagoonal and slope habitats. Monthly patterns were examined only for resident N. acutidens, and residency decreased with increasing shark length and varied seasonally for males but not females. Space use showed weak declines with increasing tidal range, and slight increases with mean air pressure, rainfall and shark length. Protecting sandflat and vegetated habitats may increase the efficacy of no-take zones for juvenile N. acutidens, because they exhibit residency and affinity to these features. Conversely, such protection will be of limited benefit for juvenile C. melanopterus, because they exhibit low residency and broader movements.
Nanoparticle amount, and not size, determines chain alignment and nonlinear hardening in polymer nanocomposites
Authors: Varol H. Samet , Meng Fanlong , Hosseinkhani Babak , Malm Christian , Bonn Daniel , Bonn Mischa , Zaccone Alessio , Parekh Sapun H.
Published: April 2017

Significance

When straining materials (e.g., pulling a rubber band), they initially deform with a certain stiffness; if one pulls harder, some materials strengthen. This phenomenon, known as nonlinear strain hardening, is a critical feature of composite polymer materials—polymers with reinforcing filler particles—used in, e.g., car tires. Engineering properties such as modulus, toughness, and strength of nanocomposites have been traditionally optimized through trial and error by changing the size and amount of fillers. Our work elucidates the molecular origin of strain hardening in polymer nanocomposites, showing that filler amount, but not size, sets the strain-hardening properties based on interfiller chain elongation. The insensitivity to filler size provides a facile concept to independently tune linear and nonlinear mechanics in composites.
Ancient individuals from the North American Northwest Coast reveal 10,000 years of regional genetic continuity
Authors: Lindo John , Achilli Alessandro , Perego Ugo A. , Archer David , Valdiosera Cristina , Petzelt Barbara , Mitchell Joycelynn , Worl Rosita , Dixon E. James , Fifield Terence E. , Rasmussen Morten , Willerslev Eske , Cybulski Jerome S. , Kemp Brian M. , DeGiorgio Michael , Malhi Ripan S.
Published: April 2017

Significance

The peopling of the Americas has been examined on the continental level with the aid of SNP arrays, next generation sequencing, and advancements in ancient DNA, all of which have helped elucidate evolutionary histories. Regional paleogenomic studies, however, have received less attention and may reveal a more nuanced demographic history. We present genome-wide sequences of individuals from the northern Northwest Coast covering a timespan of ∼10,000 years and show that continental patterns of demography do not necessarily apply on the regional level. Compared with existing paleogenomic data, we show that geographically linked population samples from the Northwest Coast exhibit an early ancestral lineage and find that population structure existed among Native North American groups as early as the late Pleistocene.
“Mr de Bussy” is More Employable than “Mr Bussy”: The Impact of a Particle Associated with the Surname of an Applicant in a Job Application Evaluation Context
Authors: Guéguen Nicolas
Published: April 2017

Previous studies examining the effect of surnames on evaluations have shown that surnames are associated with connotations which influence how we evaluate people. In this experiment, conducted in France, we examined the effect of the nobiliary particle “de” associated with a surname in a job application evaluation situation. A male applicant’s résumé was presented to participants, randomly divided into two independent groups, who were asked to evaluate him in relation to a job offer. The offer was for an assistant in human resources in a mid-size company, and the résumé was from a 23-year-old male applicant with a university education in human resources. Depending upon the experimental condition, the applicant’s full name was “Julien Bussy” or “Julien de Bussy,” but the résumé was identical in both conditions. Results indicated that the applicant whose surname included a particle was perceived to be more serious, competent, confident, and clever than the applicant without the particle. In the end, the participants in the particle condition believed that the applicant would have more chances of being selected for the job than the applicant without the particle. This effect was particularly noted with female participants. These results thus support the notion that the nobiliary particle attached to an individual’s surname has implications for people’s evaluation of that person.
From a threatening “Muslim migrant” back to the conspiring “West:” race, religion, and nationhood on Russian television during Putin's third presidency
Authors: Tolz Vera
Published: April 2017

This article analyzes official discourse of the nation during Vladimir Putin's third presidency, as reflected in Russian television coverage of Islam and migration. It argues that the replacement of earlier deliberately ambiguous definitions of Russian nationhood with clearly framed exclusive visions reflects the change in the regime's legitimation strategy from one based on economic performance to one based on its security record. In this context, the systematic promotion of Russian ethnonationalism for the purpose of achieving the regime's general stability began not at the time of Crimea's annexation, as it is often assumed, but at the time of Putin's reelection amidst public protests in 2012. The goal of representing the authorities as attentive to public grievances in a society where opinion polls register high levels of xenophobia has prompted state-controlled broadcasters to use ethnoracial definitions of the nation that they had previously avoided. The media campaigns analyzed here also reflect abrupt changes in the precise identity of Russia's main Others. Such instrumentally adopted sharp discursive swings are unlikely to constitute an appropriate tool for societal consensus management and for the achievement of political stability in the long term.
‘Believing is adapting’: Belief in a just world and emigrants’ identification and satisfaction with the host country / ‘Creer es adaptarse’: Creer en un mundo justo y la identificación y satisfacción de los emigrantes con el país de acogida
Authors: Leite Ana C. , Cardoso Sónia G. , Marques André G. , Morais Catarina
Published: April 2017

In an era in which Europe is experiencing a new wave of emigration as a result of the economic crisis, it seems socially relevant to study the processes that underlie emigrants’ adjustment to their new place of living. Research has thoroughly supported the assumption that believing in a just world is an adaptive mechanism that helps people to deal with uncertainty and harsh realities in life. We propose that the endorsement of such beliefs might also contribute to a positive identification with the host country. Using a sample of Portuguese emigrants ( N = 144), we demonstrate in a cross-sectional design that belief in a just world predicts a positive identification with the host country. In addition, positive levels of identification with the host country predicted higher levels of satisfaction with emigrant life. Theoretical and applied implications are discussed.
Validation of Fermentation and Processing Procedures for the Commercial-Scale Production of a Live, Attenuated Edwardsiella ictaluri Vaccine for Use in Channel Catfish Aquaculture
Authors: Greenway Terrence E. , Byars Todd S. , Elliot Robert B. , Jin Xixuan , Griffin Matt J. , Wise David J.
Published: April 2017

Mortality associated with Edwardsiella ictaluri infection is a serious impediment to the commercial production of fingerling Channel Catfish Ictalurus punctatus. A patented, live, attenuated, orally delivered vaccine has been developed that offers exceptional protection against E. ictaluri infection in both laboratory and small-scale pond trials. Further vaccine development is contingent on the successful completion of large-scale field trials that accurately reflect industry conditions. This current work focuses on the validation of fermentation protocols and the optimization of downstream processing procedures to produce sufficient quantities of vaccine to conduct commercial-scale field trials. Eight vaccine serials were produced from a master seed stock (S97-773-340X2) in a 50-L floor model fermenter over two consecutive years. Following fermentation, cells were harvested, concentrated 10-fold, and cryogenically stored (−74°C). To assess processing protocols and determine shelf life of cryogenically stored vaccine, serials were tested for cell viability and vaccine potency at various intervals over 24 months. There were no significant differences in cell viability between the fresh vaccine and the stored frozen product. All serials provided a high level of protection (77–100% relative percent survival) against E. ictaluri infection in juvenile Channel Catfish and exhibited excellent poststorage viability. This data demonstrates that the live, attenuated, orally delivered vaccine can be stored at −74°C for at least 2 years with no reduction in cell viability or vaccine potency.

Received May 17, 2016; accepted January 19, 2017 Published online April 4, 2017
Repetition inhibition and facilitation effects for visual-verbal stimuli under conditions of concurrent articulation
Authors: Johnson Andrew J , Hawley Ryan , Miles Christopher
Published: April 2017

This study examines the effects of within-sequence repetitions for visually presented consonants under conditions of quiet and concurrent articulation (CA). In an immediate serial recall (ISR) procedure, participants wrote down the six consonants in the order of original presentation. CA reduced serial recall and abolished the phonological similarity effect. However, the effects of within-trial repetitions were broadly similar under quiet and CA. Specifically, adjacent repetitions facilitated recall of the repeated item, whereas spaced repetitions (separated by three intervening items) impaired recall accuracy for the repeated item (i.e., the Ranschburg effect). These data are the first to demonstrate the Ranschburg effect for visual-verbal stimuli under CA.
Orthographic processing: A ‘mid-level’ vision of reading: The 44th Sir Frederic Bartlett Lecture
Authors: Grainger Jonathan
Published: April 2017

I will describe how orthographic processing acts as a central interface between visual and linguistic processing during reading, and as such can be considered to be the ‘mid-level vision’ of reading research. In order to make this case, I first summarize the evidence in favour of letter-based word recognition before examining work investigating how orthographic similarities among words influence single word reading. I describe how evidence gradually accumulated against traditional measures of orthographic similarity and the associated theories of orthographic processing, forcing a reconsideration of how letter-position information is represented by skilled readers. Then, I present the theoretical framework that was developed to explain these findings, with a focus on the distinction between location-specific and location-invariant orthographic representations. Finally, I describe work extending this theoretical framework in two main directions: first, to the realm of reading development, with the aim to specify the key changes in the processing of letters and letter strings that accompany successful learning to read, and second, to the realm of sentence reading, in order to specify how orthographic information can be processed across several words in parallel, and how skilled readers keep track of which letters belong to which words.
Forecasting the Quarterly Production of Rice and Corn in the Philippines: A Time Series Analysis
Authors: Urrutia Jackie D. , Diaz John Lean B. , Mingo Francis Leo T.
Published: April 2017

Rice and corn are crops that are produced on most of the agricultural areas in the Philippine geographic territory. Gathered from the Philippine Statistics Authority (PSA), the quarterly volume of total production of the mentioned crops will be predicted using Seasonal Autoregressive Integrated Moving Average (SARIMA) Modelling through a Box-Jerkins method of forecasting. Investigators aims to forecast rice production and Corn production actual observed in the next 5 years of data, particularly in years mentioned. Obtaining models through SARIMA method, for rice production is SARIMA (2 1 8) (1 1 0)4 and for Corn production would be SARIMA (3 1 8) (0 1 1)4. Results suggest that two models have satisfactorily fitted their specified series and diagnostic checking for models’ accuracy. The dynamically forecasted values of both series were following the trend pattern of the past values of their allotted observed values which were going on an upward direction indicating favourable outcome for the study. This may help people for better understanding the possible changes in values of the data series gathered and may even help the government for any reforms they can make for the upward mobility of production of crops, in agriculture and especially, economy of the country.
The Synthesis and Characterization of Ag/Ag2O/TiO2/NGP Composites as Adsorbents and Photocatalysts for Wastewater Removal
Authors: Taufik A. , Prakoso S.P. , Saleh R.
Published: April 2017

An Ag/Ag2O/TiO2/NGP with different nanographene platelets (NGP) weight percents was synthesized using the hydrothermal method. The NGP weight percent was 5, 10, and 15 weight percent, respectively. The structural properties of the samples were characterized by X-ray diffraction. The optical properties of the samples were investigated by UV-Vis spectroscopy and their thermal properties were investigated by Thermo Gravimetric Analysis and Differential Thermal Analysis. The existence of a cubic structure from Ag and Ag2O, an anatase from TiO2, and a graphitic like structure from NGP indicated that the samples were successfully formed. The maximum light absorption at 435 nm indicated the existence of surface plasmon resonance (SPR) from silver nanoparticles. The phase transformation of Ag2O to Ag occurred at 435 °C. Adsorption and the photocatalytic performance were investigated in the degradation of methylene blue from the aqueous solution. The adsorption ability of Ag/Ag2O/TiO2/NGP composites increased by increasing the NGP weight percent. The adsorption process of MB followed pseudo-second-order kinetic reactions. The photocatalytic activity of Ag/Ag2O/TiO2/NGP showed that Ag/Ag2O/TiO2/NGP with a 10 weight percent NGP exhibited the highest photocatalytic performance, with a removal ability of approximately 96 percent.
Convolution quadrature for the wave equation with a nonlinear impedance boundary condition
Authors: Banjai Lehel , Rieder Alexander
Published: April 2017

A rarely exploited advantage of time-domain boundary integral equations compared to their frequency counterparts is that they can be used to treat certain nonlinear problems. In this work we investigate the scattering of acoustic waves by a bounded obstacle with a nonlinear impedance boundary condition. We describe a boundary integral formulation of the problem and prove without any smoothness assumptions on the solution the convergence of a full discretization: Galerkin in space and convolution quadrature in time. If the solution is sufficiently regular, we prove that the discrete method converges at optimal rates. Numerical evidence in 3D supports the theory.
Interarm Difference in Systolic Blood Pressure in Different Ethnic Groups and Relationship to the “White Coat Effect”: A Cross-Sectional Study
Authors: Schwartz Claire Lorraine , Clark Christopher , Koshiaris Constantinos , Gill Paramjit S , Greenfield Shelia M , Haque Sayeed M , Heer Gurdip , Johal Amanpreet , Kaur Ramandeep , Mant Jonathan , Martin Una , Mohammed Mohamed A , Wood Sally , McManus Richard J
Published: April 2017

BACKGROUND

Interarm differences (IADs) ≥10 mm Hg in systolic blood pressure (BP) are associated with greater incidence of cardiovascular disease. The effect of ethnicity and the white coat effect (WCE) on significant systolic IADs (ssIADs) are not well understood.

METHODS

Differences in BP by ethnicity for different methods of BP measurement were examined in 770 people (300 White British, 241 South Asian, 229 African-Caribbean). Repeated clinic measurements were obtained simultaneously in the right and left arm using 2 BPTru monitors and comparisons made between the first reading, mean of second and third and mean of second to sixth readings for patients with, and without known hypertension. All patients had ambulatory BP monitoring (ABPM). WCE was defined as systolic clinic BP ≥10 mm Hg higher than daytime ABPM.

RESULTS

No significant differences were seen in the prevalence of ssIAD between ethnicities whichever combinations of BP measurement were used and regardless of hypertensive status. ssIADs fell between the 1st measurement (161, 22%), 2nd/3rd (113, 16%), and 2nd–6th (78, 11%) (1st vs. 2nd/3rd and 2nd–6th, P < 0.001). Hypertensives with a WCE were more likely to have ssIADs on 1st, (odds ratio [OR] 1.73 (95% confidence interval 1.04–2.86); 2nd/3rd, (OR 3.05 (1.68–5.53); and 2nd–6th measurements, (OR 2.58 (1.22–5.44). Nonhypertensive participants with a WCE were more likely to have a ssIAD on their first measurement (OR 3.82 (1.77 to −8.25) only.

CONCLUSIONS

ssIAD prevalence does not vary with ethnicity regardless of hypertensive status but is affected by the number of readings, suggesting the influence of WCE. Multiple readings should be used to confirm ssIADs.
Genetic Influence on the Sulcal Pits: On the Origin of the First Cortical Folds
Authors: Le Guen Yann , Auzias Guillaume , Leroy François , Noulhiane Marion , Dehaene-Lambertz Ghislaine , Duchesnay Edouard , Mangin Jean-François , Coulon Olivier , Frouin Vincent
Published: April 2017

The influence of genes on cortical structures has been assessed through various phenotypes. The sulcal pits, which are the putative first cortical folds, have for long been assumed to be under tight genetic control, but this was never quantified. We estimated the pit depth heritability in various brain regions using the high quality and large sample size of the Human Connectome Project pedigree cohort. Analysis of additive genetic variance indicated that their heritability ranges between 0.2 and 0.5 and displays a regional genetic control with an overall symmetric pattern between hemispheres. However, a noticeable asymmetry of heritability estimates is observed in the superior temporal sulcus and could thus be related to language lateralization. The heritability range estimated in this study reinforces the idea that cortical shape is determined primarily by nongenetic factors, which is consistent with the important increase of cortical folding from birth to adult life and thus predominantly constrained by environmental factors. Nevertheless, the genetic cues, implicated with various local levels of heritability in the formation of sulcal pits, play a fundamental role in the normal gyral pattern development. Quantifying their influence and identifying the underlying genetic variants would provide insight into neurodevelopmental disorders.
Prediction of adverse events after catheter-based procedures in adolescents and adults with congenital heart disease in the IMPACT registry
Authors: Stefanescu Schmidt Ada C. , Armstrong Aimee , Kennedy Kevin F. , Nykanen David , Aboulhosn Jamil , Bhatt Ami B.
Published: April 2017

Aims

We sought to identify factors associated with major adverse events (MAE) after cardiac catheterization in adolescents and adults with congenital heart disease (CHD), and create the first model to individualize risk discussions in this growing population.

Methods and results

Improving Pediatric and Adult Congenital Treatment (IMPACT), a National Cardiovascular Data Registry, contains congenital catheterization data from over 87 hospitals in the United States. Demographics, pre-procedure, and procedural variables were collected for patients over age 10. Multivariable logistic regression was used to identify significant predictors of MAE, a composite of death, urgent surgery or procedure due to a catheterization complication, transfusion, embolic stroke, tamponade, extracorporeal membrane oxygenation or ventricular assist device placement, and device embolization, malposition or thrombosis requiring surgical intervention. A risk score was built based on the effect sizes of each predictor and validated in a split sample. A MAE occurred in 686 (2.5%) of the 27 293 index procedures meeting inclusion criteria. The independent multivariate predictors of MAE were older age, pre-procedural anticoagulation use, renal disease, lower haemoglobin, lower oxygen saturation, non-elective procedure, higher index procedure risk and having had no prior cardiac procedures. Being underweight or overweight had borderline significance and was added to the model. The C-statistic for the model was robust at 0.787 in the derivation and 0.773 in the validation cohort.

Conclusion

The factors predicting adverse events after cardiac catheterization in adolescents and adults with CHD are different than in the general population. Validation of this model in other national or multi-institutional datasets is the next step.
Realistic dosimetry for studies on biological responses to X-rays and γ-rays
Authors: Shahmohammadi Beni Mehrdad , Krstic Dragana , Nikezic Dragoslav , Yu Kwan Ngok
Published: April 2017

A calibration coefficient R (= DA/DE) for photons was employed to characterize the photon dose in radiobiological experiments, where DA was the actual dose delivered to cells and DE was the dose recorded by an ionization chamber. R was determined using the Monte Carlo N-Particle version 5 (MCNP-5) code. Photons with (i) discrete energies, and (ii) continuous-energy distributions under different beam conditioning were considered. The four studied monoenergetic photons had energies E = 0.01, 0.1, 1 and 2 MeV. Photons with E = 0.01 MeV gave R values significantly different from unity, while those with E > 0.1 MeV gave R ≈ 1. Moreover, R decreased monotonically with increasing thickness of water medium above the cells for E = 0.01, 1 or 2 MeV due to energy loss of photons in the medium. For E = 0.1 MeV, the monotonic pattern no longer existed due to the dose delivered to the cells by electrons created through the photoelectric effect close to the medium–cell boundary. The continuous-energy distributions from the X-Rad 320 Biological Irradiator (voltage = 150 kV) were also studied under three different beam conditions: (a) F0: no filter used, (b) F1: using a 2 mm-thick Al filter, and (c) F2: using a filter made of (1.5 mm Al + 0.25 mm Cu + 0.75 mm Sn), giving mean output photon energies of 47.4, 57.3 and 102 keV, respectively. R varied from ~1.04 to ~1.28 for F0, from ~1.13 to ~1.21 for F1, and was very close to unity for F2.
How Physically Active Are People Following Stroke? Systematic Review and Quantitative Synthesis
Authors: Fini Natalie A. , Holland Anne E. , Keating Jenny , Simek Jacinta , Bernhardt Julie
Published: April 2017

Background. Mobility limitations are common following stroke and frequently lead to poor participation in physical activity (PA).

Purpose. The purpose of this study was to describe PA across the various stages following stroke (acute, subacute, and chronic).

Data Sources. Searches were conducted in 5 databases.

Study Selection. Eligible studies included participants with stroke whose PA was quantitatively measured for at least 4 hours in a single session. Two reviewers independently reviewed titles and abstracts.

Data Extraction. One reviewer extracted data and assessed quality using the Downs and Black checklist. Weighted means were calculated for PA outcomes.

Data Synthesis. Searches yielded 103 eligible papers including 5306 participants aged 21 to 96 years. Devices (eg, activity monitors) were used in 73 papers, and behavioral mapping (observational monitoring) in 30. Devices show that people with stroke took on average 5535 steps per day (n = 406, 10 studies) in the subacute phase and 4078 steps (n = 1280, 32 studies) in the chronic phase. Average daily walking duration (% measured time) was higher in the chronic phase (9.0%, n = 100) than subacute (1.8%, n = 172), and sedentary time was >78% regardless of time post stroke. Acute data were lacking for these variables. Matched healthy individuals took an average of 8338 steps per day (n = 129). Behavioral mapping showed time in bed was higher in the acute than subacute phase (mean 45.1% versus 23.8%), with similar time spent sitting (mean 37.6% versus 32.6%).

Limitations. Limitations of this review include not pooling data reported as medians.

Conclusions. Physical activity levels do not meet guidelines following stroke. Time spent inactive and sedentary is high at all times. Increasing PA and developing standardized activity targets may be important across all stages of stroke recovery.
Simulation Fellowship Programs: An International Survey of Program Directors
Authors: Natal Brenda , Szyld Demian , Pasichow Scott , Bismilla Zia , Pirie Jonathan , Cheng Adam
Published: April 2017

Purpose

To report on the evolution of simulation-based training (SBT) by identifying the composition and infrastructure of existing simulation fellowship programs, describing the current training practices, disclosing existing program barriers, and highlighting opportunities for standardization.

Method

Investigators conducted a cross-sectional survey study among English-speaking simulation fellowship program directors (September 2014–September 2015). They identified fellowships through academic/institutional Web sites, peer-reviewed literature, Web-based search engines, and snowball sampling. They invited programs to participate in the Web-based questionnaire via e-mail and follow-up telephone calls.

Results

Forty-nine programs met the inclusion criteria. Of these, 32 (65%) responded to the survey. Most programs were based in the United States, but others were from Canada, England, and Australia. Over half of the programs started in or after 2010. Across all 32 programs, 186 fellows had graduated since 1998. Fellows and directors were primarily departmentally funded; programs were primarily affiliated with hospitals and/or medical schools, many of which had sponsoring centers accredited by governing bodies. Fellows were typically medical trainees; directors were typically physicians. The majority of programs (over 90%) covered four core objectives, and all endorsed similar educational outcomes. Respondents identified no significant universal barriers to program success. Most directors (18/28 [64%]) advocated standardized fellowship guidelines on a national level.

Conclusions

Paralleling the fast growth and integration of SBT, fellowship training opportunities have grown rapidly in the United States, Canada, and beyond. This study highlights potential areas for standardization and accreditation of simulation fellowships which would allow measurable competencies in graduates.