bluuebunny/crossref_metadata_2025 huggingface dataset:
Symmetry breaking and excitonic effects on optical properties of defective nanographenes
Authors: Noguchi Yoshifumi , Sugino Osamu
Published: February 2015

We investigate optical properties of the nanographene family and predict a defect induced effect by utilizing the all-electron first-principles GW+Bethe-Salpeter equation (BSE) method based on the many-body perturbation theory. As an accuracy check of the GW+BSE, photoabsorption spectra are calculated for a grossly warped nanographene (C80H30), which was very recently synthesized [Kawasumi et al., Nat. Chem. 5, 739–744 (2013)]. The calculated spectra are found to faithfully reproduce the shape, height, and position of the measured peaks. Then the method is applied to the flat nanographene without defect (C24H12 and C38H16), the curved ones with single defect (C20H10, C28H14, and C32H16), and fragments of C80H30 with double defect (C36H16 and C42H20). The existence of the defects significantly changes the optical spectra. In particular, the interaction between the defects is found to break the symmetry of the atomic geometries and enhance the excitonic effect, thereby generating the extra peaks at the lower photon energy side of the main peak. The present results might help explain the origin of the first two peaks experimentally observed for C80H30.
Hairpin vortices in turbulent boundary layers
Authors: Eitel-Amor G. , Örlü R. , Schlatter P. , Flores O.
Published: February 2015

The present work presents a number of parallel and spatially developing simulations of boundary layers to address the question of whether hairpin vortices are a dominant feature of near-wall turbulence, and which role they play during transition. In the first part, the parent–offspring regeneration mechanism is investigated in parallel (temporal) simulations of a single hairpin vortex introduced in a mean shear flow corresponding to either turbulent channels or boundary layers (Reτ ≲ 590). The effect of a turbulent background superimposed on the mean flow is considered by using an eddy viscosity computed from resolved simulations. Tracking the vortical structure downstream, it is found that secondary hairpins are only created shortly after initialization, with all rotational structures decaying for later times. For hairpins in a clean (laminar) environment, the decay is relatively slow, while hairpins in weak turbulent environments (10% of νt) dissipate after a couple of eddy turnover times. In the second part, the role of hairpin vortices in laminar–turbulent transition is studied using simulations of spatial boundary layers tripped by hairpin vortices. These vortices are generated by means of specific volumetric forces representing an ejection event, creating a synthetic turbulent boundary layer initially dominated by hairpin-like vortices. These hairpins are advected towards the wake region of the boundary layer, while a sinusoidal instability of the streaks near the wall results in rapid development of a turbulent boundary layer. For Reθ > 400, the boundary layer is fully developed, with no evidence of hairpin vortices reaching into the wall region. The results from both the parallel and spatial simulations strongly suggest that the regeneration process is rather short-lived and may not sustain once a turbulent background is developed. From the transitional flow simulations, it is conjectured that the forest of hairpins reported in former direct numerical simulation studies is reminiscent of the transitional boundary layer and may not be connected to some aspects of the dynamics of the fully developed wall-bounded turbulence.
Accuracy of buffered-force QM/MM simulations of silica
Authors: Peguiron Anke , Colombi Ciacchi Lucio , De Vita Alessandro , Kermode James R. , Moras Gianpietro
Published: February 2015

We report comparisons between energy-based quantum mechanics/molecular mechanics (QM/MM) and buffered force-based QM/MM simulations in silica. Local quantities—such as density of states, charges, forces, and geometries—calculated with both QM/MM approaches are compared to the results of full QM simulations. We find the length scale over which forces computed using a finite QM region converge to reference values obtained in full quantum-mechanical calculations is ∼10 Å rather than the ∼5 Å previously reported for covalent materials such as silicon. Electrostatic embedding of the QM region in the surrounding classical point charges gives only a minor contribution to the force convergence. While the energy-based approach provides accurate results in geometry optimizations of point defects, we find that the removal of large force errors at the QM/MM boundary provided by the buffered force-based scheme is necessary for accurate constrained geometry optimizations where Si–O bonds are elongated and for finite-temperature molecular dynamics simulations of crack propagation. Moreover, the buffered approach allows for more flexibility, since special-purpose QM/MM coupling terms that link QM and MM atoms are not required and the region that is treated at the QM level can be adaptively redefined during the course of a dynamical simulation.
Topological insulator: Bi2Se3/polyvinyl alcohol film-assisted multi-wavelength ultrafast erbium-doped fiber laser
Authors: Guo Bo , Yao Yong , Yang Yan-Fu , Yuan Yi-Jun , Wang Rui-Lai , Wang Shu-Guang , Ren Zhong-Hua , Yan Bo
Published: February 2015

We experimentally demonstrate a multi-wavelength ultrafast erbium-doped fiber laser incorporating a μm-scale topological insulator: Bi2Se3/Polyvinyl Alcohol film as both an excellent saturable absorber for mode-locking and a high-nonlinear medium to induce a giant third order optical nonlinear effect for mitigating the mode competition of erbium-doped fiber laser and stabilizing the multi-wavelength oscillation. By properly adjusting the pump power and the polarization state, the single-, dual-, triple-, four-wavelength mode-locking pulse could be stably initiated. For the four-wavelength operation, we obtain its pulse width of ∼22 ps and a fundamental repetition rate of 8.83 MHz. The fiber laser exhibits the maximum output power of 9.7 mW with the pulse energy of 1.1 nJ and peak power of 50 W at the pump power of 155 mW. Our study shows that the simple, stable, low-cost multi-wavelength ultrafast fiber laser could be applied in various potential fields, such as optical communication, biomedical research, and radar system.
Radiative energy and momentum transfer for various spherical shapes: A single sphere, a bubble, a spherical shell, and a coated sphere
Authors: Zheng Yi , Ghanekar Alok
Published: February 2015

We use fluctuational electrodynamics to determine spectral emissivity and van der Waals contribution to surface energy for various spherical shapes, such as a sphere, a bubble, a spherical shell, and a coated sphere, in a homogeneous and isotropic medium. The dyadic Green's function formalism of radiative energy and fluctuation-induced van der Waals stress for different spherical configurations has been developed. We show (1) emission spectra of micro- and nano-sized single and coated spheres display several emissivity sharp peaks as the size of object reduces and (2) surface energy becomes size dependent due to van der Waals phenomena when size of object is reduced to a nanoscopic length scale.
Spatial analysis of renewable energy potential and use in Turkey
Authors: Güngör-Demirci Gamze
Published: February 2015

Turkey is known to be rich in terms of renewable energy. Efficient use of renewable energy resources requires analysis of their spatial distribution as these resources are not equally distributed throughout the country. The aim of this study is to investigate the current use and the available potential of hydraulic, wind, geothermal, solar, and biomass energy in Turkey on a spatial basis using Geographic Information Systems. The results show that renewable energy resources are distributed over the country, and countrywide utilization of renewable energy is possible. However, a very limited portion of the available potential is currently in use. The eastern part of the country has a remarkable hydraulic energy potential, whereas the western part has high wind and geothermal energy potential. The western and central parts of the country are rich in terms of biomass energy potential, while the southern and southeastern parts have plentiful solar energy. As an energy importing country, Turkey needs to increase the potential and use of its renewable energy resources. For this purpose, a strong renewable energy policy needs to be established, and some enhancements in current implementations need to be made. Spatial analysis is a powerful tool to help policy makers and implementers during the establishment and enhancement processes.
Theory of unidirectional spin heat conveyer
Authors: Adachi Hiroto , Maekawa Sadamichi
Published: February 2015

We theoretically investigate the unidirectional spin heat conveyer effect recently reported in the literature that emerges from the Damon-Eshbach spin wave on the surface of a magnetic material. We develop a simple phenomenological theory for heat transfer dynamics in a coupled system of phonons and the Damon-Eshbach spin wave, and demonstrate that there arises a direction-selective heat flow as a result of the competition between an isotropic heat diffusion by phonons and a unidirectional heat drift by the spin wave. The phenomenological approach can account for the asymmetric local temperature distribution observed in the experiment.
Alternative material study for heat assisted magnetic recording transducer application
Authors: Xu B. X. , Cen Z. H. , Hu J. F. , Tsai J. W. H.
Published: February 2015

In heat assisted magnetic recording (HAMR), optical near field transducer (NFT) is a key component. Au is currently used as NFT material because of its strong surface plasmon effect. Due to the soft property of Au material, reliability of Au NFT becomes a key issue for realizing HAMR production. In this paper, the possibility of alternative materials, including transition metal nitrides (TMNs) and transparent conducting oxides (TCOs) to replace Au is studied. The results show that all of the listed TMN and TCO materials can meet the mechanical requirements at room temperature in terms of hardness and thermal expansion. An optical model, which includes optical waveguide, NFT and FePt media, is used to simulate NFT performances. The results indicate that the resonant wavelengths for NFT with TCO materials are longer than 1500 nm, which is not suitable for HAMR application. TMN materials are suitable for NFT application at wavelength band of around 800 nm. But the NFT efficiency is very low. ZrN is the best material among TMN materials and the efficiency of ZrN NFT is only 13% of the Au NFT's efficiency. Reducing refractive index (n) and increasing extinction coefficient (k) will both lead to efficiency increase. Increasing k contributes more in the efficiency increase, while reducing n has a relatively low NFT absorption. For materials with the same figure of merit, the NFT with larger k material has higher efficiency. Doping materials to increase the material conduction electron density and growing film with larger size grain may be the way to increase k and reduce n.
Elastodynamic metasurface: Depolarization of mechanical waves and time effects
Authors: Boutin Claude , Schwan Logan , Dietz Matthew S.
Published: February 2015

We report the concept of microstructured surfaces with inner resonance in the field of elastodynamics, so-called elastodynamic metasurfaces. Such metasurfaces allow for wavefield manipulation of mechanical waves by tuning the boundary conditions at specific frequencies. In particular, they can be used to depolarize elastic waves without introducing heterogeneities in the medium itself; the physical means to do so in homogeneous elastic media used to remain, surprisingly, an open question while depolarization is commonplace in electromagnetism. The principle relies on the anisotropic behaviour of a subwavelength array of resonators: Their subwavelength configuration confines the Bragg interferences scattered by resonators into a boundary layer. The effective behaviour of the resonating array is expressed with homogenization as an unconventional impedance, the frequency-dependence, and anisotropy of which lead to depolarization and time effects. The concept of the elastodynamic metasurface is tested experimentally and results bear testament to its efficacy and robustness. Elastodynamic metasurfaces are easily realized and analytically predictable, opening new possibilities in tomography techniques, ultrasonics, geophysics, vibration control, materials and structure design.
Ferromagnetic resonance in nanoscale CoFeB/MgO magnetic tunnel junctions
Authors: Hirayama E. , Kanai S. , Sato H. , Matsukura F. , Ohno H.
Published: February 2015

We investigate the junction size dependence of magnetic properties of a CoFeB free layer in CoFeB/MgO magnetic tunnel junctions (MTJs) by homodyne-detected ferromagnetic resonance, where the diameter of the circular MTJs is varied from 35 nm to 100 nm. We observe the increase of the effective perpendicular magnetic anisotropy field and the apparent damping constant in the free layers with decreasing diameter.
5.5 W near-diffraction-limited power from resonant leaky-wave coupled phase-locked arrays of quantum cascade lasers
Authors: Kirch J. D. , Chang C.-C. , Boyle C. , Mawst L. J. , Lindberg D. , Earles T. , Botez D.
Published: February 2015

Five, 8.36 μm-emitting quantum-cascade lasers (QCLs) have been monolithically phase-locked in the in-phase array mode via resonant leaky-wave coupling. The structure is fabricated by etch and regrowth which provides large index steps (Δn = 0.10) between antiguided-array elements and interelement regions. Such high index contrast photonic-crystal (PC) lasers have more than an order of magnitude higher index contrast than PC-distributed feedback lasers previously used for coherent beam combining in QCLs. Absorption loss to metal layers inserted in the interelement regions provides a wide (∼1.0 μm) range in interelement width over which the resonant in-phase mode is strongly favored to lase. Room-temperature, in-phase-mode operation with ∼2.2 kA/cm2 threshold-current density is obtained from 105 μm-wide aperture devices. The far-field beam pattern has lobewidths 1.65× diffraction limit (D.L.) and 82% of the light in the main lobe, up to 1.8× threshold. Peak pulsed near-D.L. power of 5.5 W is obtained, with 4.5 W emitted in the main lobe. Means of how to increase the device internal efficiency are discussed.
Light polarization sensitive photodetectors with m- and r-plane homoepitaxial ZnO/ZnMgO quantum wells
Authors: Tabares G. , Hierro A. , Lopez-Ponce M. , Muñoz E. , Vinter B. , Chauveau J.-M.
Published: February 2015

Homoepitaxial ZnO/(Zn,Mg)O multiple quantum wells (MQWs) grown with m- and r-plane orientations are used to demonstrate Schottky photodiodes sensitive to the polarization state of light. In both orientations, the spectral photoresponse of the MQW photodiodes shows a sharp excitonic absorption edge at 3.48 eV with a very low Urbach tail, allowing the observation of the absorption from the A, B and C excitonic transitions. The absorption edge energy is shifted by ∼30 and ∼15 meV for the m- and r-plane MQW photodiodes, respectively, in full agreement with the calculated polarization of the A, B, and C excitonic transitions. The best figures of merit are obtained for the m-plane photodiodes, which present a quantum efficiency of ∼11%, and a specific detectivity D* of ∼6.4 × 1010 cm Hz1/2/W. In these photodiodes, the absorption polarization sensitivity contrast between the two orthogonal in-plane axes yields a maximum value of (R⊥/R||)max ∼ 9.9 with a narrow bandwidth of ∼33 meV.
Early stages of spinodal decomposition in Fe–Cr resolved by in-situ small-angle neutron scattering
Authors: Hörnqvist M. , Thuvander M. , Steuwer A. , King S. , Odqvist J. , Hedström P.
Published: February 2015

In-situ, time-resolved small-angle neutron scattering (SANS) investigations of the early stages of the spinodal decomposition process in Fe–35Cr were performed at 773 and 798 K. The kinetics of the decomposition, both in terms of characteristic distance and peak intensity, followed a power-law behaviour from the start of the heat treatment (a′ = 0.10–0.11 and a″ = 0.67–0.86). Furthermore, the method allows tracking of the high–Q slope, which is a sensitive measure of the early stages of decomposition. Ex-situ SANS and atom probe tomography were used to verify the results from the in-situ investigations. Finally, the in-situ measurement of the evolution of the characteristic distance at 773 K was compared with the predictions from the Cahn-Hilliard-Cook model, which showed good agreement with the experimental data (a′ = 0.12–0.20 depending on the assumed mobility).
Electron beam induced current profiling of the p-ZnO:N/n-GaN heterojunction
Authors: Przeździecka E. , Stachowicz M. , Chusnutdinow S. , Jakieła R. , Kozanecki A.
Published: February 2015

The high quality p-n structures studied consist of nitrogen doped ZnO:N films grown by plasma assisted molecular beam epitaxy on n-type GaN templates. The nitrogen concentration, determined by secondary ion mass spectroscopy, is about 1 × 1020 cm−3. Temperature dependent photoluminescence studies confirm the presence of acceptor centers with an energy level lying approximately 130 meV above the valence band. The maximum forward-to-reverse current ratio IF/IR in the obtained p-n diodes is about 107 at ±5 V, which is 2–5 orders of magnitude higher than previously reported for this type of heterojunctions. Electron-beam-induced current measurements confirm the presence of a p–n junction, located at the p-ZnO/n-GaN interface. The calculated diffusion length and activation energy of minority carriers are presented. The heterostructures exhibit strong absorption in the UV range with a four orders of magnitude high bright-to-dark current ratio.
Terahertz harmonic generation in graphene
Authors: Sekwao Samwel , Leburton Jean-Pierre
Published: February 2015

We show that charge carrier transport in graphene exhibits sharp resonances in the presence of spatially and temporarily modulated scattering. Resonances occur when the period of an applied a–c field corresponds to the time taken by quasi-ballistic carriers to drift over a spatial scattering period, provided the latter is shorter than the distance taken by carriers to emit an optic phonon. We show that such system can be achieved with interdigitated gates energized with an a–c bias on graphene layers. Gate separation and fields to achieve ballistic transport would result in resonances in the terahertz range, with the generation of higher harmonics characterized by large Q-factors, which are tunable with gate spacing.
Limiting efficiency calculation of silicon single-nanowire solar cells with considering Auger recombination
Authors: Zhai Xiongfei , Wu Shaolong , Shang Aixue , Li Xiaofeng
Published: February 2015

Single-nanowire solar cells (SNSCs) have attracted considerable attention due to their unique light-harvesting capability mediated by the optical antenna effect and the high photoconversion efficiency due to the orthogonalization of the carrier collection to the photon incidence. We present a detailed prediction of the light-conversion efficiency of Si SNSCs based on finite-element simulation and thermodynamic balance analysis, with especially focusing on the comparison between SNSCs and film systems. Carrier losses due to radiative and Auger recombinations are introduced in the analysis of the limiting efficiency, which show that the Auger recombination plays a key role in accurately predicting the efficiency of Si SNSCs, otherwise, the device performance would be strongly overestimated. The study paves a more realistic way to evaluate the nanostructured solar cells based on indirect-band photoactive materials.
Genomic scan for identifying candidate genes for paratuberculosis resistance in sheep
Authors: Moioli Bianca , D'Andrea Silvia , De Grossi Luigi , Sezzi Erminia , De Sanctis Bruno , Catillo Gennaro , Steri Roberto , Valentini Alessio , Pilla Fabio
Published: February 2015

Breeding objectives relating to health, functional traits and welfare need to receive priority in the research programs and selection schemes, but very few reports are available on natural resistant genotypes in livestock, where some important diseases cause severe economic losses and pose serious zoonotic threats. In this study, diagnosis of paratuberculosis was performed on 759 adult sheep, from a single flock, with the serum antibody enzyme-linked immunosorbent assay; 100 sheep were selected among the extreme divergent animals for the S/P ratio obtained from the test, and were genotyped on the Illumina Ovine SNP50K BeadChip. A genome-wide scan was then performed on the individual marker genotypes, in the attempt to identify genomic regions associated with disease resistance in sheep. For each marker, the allelic substitution effect was calculated by regressing the S/P value on the number of copies of the reference allele. The position on the OARv3.1 Genome Assembly was searched for 32 markers, which showed a statistically significant allelic substitution effect (Raw P < 0.0006 and FDR P < 0.09). All markers were located within, or close to, annotated genes. Five of these genes, SEMA3, CD109, PCP4, PRDM2 and ITFG2 are referred in literature to play a role in either disease resistance or cell-mediated immune response.
A generic, empirical-based model for predicting rate of fire spread in shrublands
Authors: Anderson Wendy R. , Cruz Miguel G. , Fernandes Paulo M. , McCaw Lachlan , Vega Jose Antonio , Bradstock Ross A. , Fogarty Liam , Gould Jim , McCarthy Greg , Marsden-Smedley Jon B. , Matthews Stuart , Mattingley Greg , Pearce H. Grant , van Wilgen Brian W.
Published: February 2015

A shrubland fire behaviour dataset was assembled using data from experimental studies in Australia, New Zealand, Europe and South Africa. The dataset covers a wide range of heathlands and shrubland species associations and vegetation structures. Three models for rate of spread are developed using 2-m wind speed, a wind reduction factor, elevated dead fuel moisture content and either vegetation height (with or without live fuel moisture content) or bulk density. The models are tested against independent data from prescribed fires and wildfires and found to predict fire spread rate within acceptable limits (mean absolute errors varying between 3.5 and 9.1 m min–1). A simple model to predict dead fuel moisture content is evaluated, and an ignition line length correction is proposed. Although the model can be expected to provide robust predictions of rate of spread in a broad range of shrublands, the effects of slope steepness and variation in fuel quantity and composition are yet to be quantified. The model does not predict threshold conditions for continuous fire spread, and future work should focus on identifying fuel and weather factors that control transitions in fire behaviour.
What’s in a name
Authors: Gladkova Olga , DiMarco Chrysanne , Harris Randy Allen
Published: February 2015

We survey the disciplinary status and the research trends of argumentation studies. Our investigation combines the methods of a literature review and environmental scan. The latter consists in analysis of the linguistic features of journal titles, which we approach as a type of metacommunication. The results of our environmental scan suggest that the authors contributing to argumentation research envision it as a well-integrated field with a complex system of relations among the communities, agendas, methods, and venues involved in it. Yet we also found that the field is often seen as divided along the lines of binary oppositions between theory and its applications, as well as between theoretical and empirical research. We found that the field is increasingly turning to empirical, applied, and professional research, while the status of scholarly research is declining. Our analysis suggests that argumentation studies is developing a more sophisticated and tractable theory and methodology
Suspicion as an argumentative move
Authors: Palmieri Rudi , Rigotti Eddo
Published: February 2015

In order to comply with Anti-Money Laundering (AML) laws, financial intermediaries are being engaged with unprecedented communicative activities, mainly oriented at detecting suspicious activities which must be reported to the Financial Intelligence Unit. The polysemous notion of ‘suspicion’ is pivotal to these communicative activities and needs to be clarified in order to establish to what extent argumentation is involved in their fulfillment. To this purpose, we apply the method of semantic analysis developed within Congruity Theory bringing to light the different semantic values of the verb ‘to suspect’ and its lexical derivates in a corpus of ordinary English; then we compare these meanings with the actual uses of this verb in the international and national AML laws. Amongst the numerous factors contributing to the polysemy of this word, we focalize on the difference emerged between an argumentative value of ’to suspect’ and another meaning in which suspicion is reduced to a mere hunch. This suggests that there exist different types of suspicion acts which are more or less argumentative. Interestingly, anti-money laundering international standards and some national implementations seem to admit suspicions at different argumentative degrees, entailing different levels of critical assessment expected from the financial intermediary. We also identify important implications for bank’s anti-money laundering activities deriving from the different semantic traits emerged in the analysis. We conclude the paper by eliciting from the outcome of the semantic analysis a number of questions that will guide the next steps of an ongoing research project in which Swiss banks’ AML practices are investigated from an argumentative perspective.
Overcoming preferred argument structure in written French
Authors: Mazur-Palandre Audrey
Published: February 2015

Spoken and written French contrast in many ways. Our goal here is to show how later language development is profoundly impacted by experience with written language. More than 120 French-speakers/ writers, one group of children (mean age: 10;9) and two groups of adolescents (mean age: 12;7 and 15;2), participated in this study. Our analysis of noun phrases is inspired by the hypothesis ofPreferred Argument Structure(Du Bois 1987) and examines referential cohesion in texts produced in contexts differing in modality (spoken – written) and text type (expository – narrative). Our aim is to demonstrate: (a) that spoken language production is governed by discursive constraints which control the flow of information; and (b) these discursive constraints differ for written and spoken production. Part of learning to become a literate user of French involves overcoming the discourse constraints governing spoken language production.
Aer yuo looking cloesly? Even good spellers are impacted by partial cue reading
Authors: Kwong Tru E. , Desjarlais Malinda , L. Duffy Megan
Published: February 2015

Differences in letter string processing between better and relatively poorer (average) spellers were examined. Forty undergraduate students completed a simultaneous orthographic matching task judging pairs of letter strings as same or different. Reading exposure, spelling, and reading habits were measured. Significant differences in reaction times, but not accuracy, were found between the two groups. When the groups were combined, a negative correlation was found between reaction time in the matching task and spelling ability. Taken together, these results suggest that unexpectedly poorer spellers tend to read words based on partial cues, while excellent spellers attend to entire words. Further, results indicate that processing partial vs. full cues may be a continuum, rather than a dichotomy, with even average spellers processing less than do excellent spellers. These results have implications for how unexpectedly poor spellers are defined in research and for the range of individuals who could improve their spelling by processing fuller cues.
Implicit and explicit instruction
Authors: Cordewener Kim A.H. , Bosman Anna M.T. , Verhoeven Ludo
Published: February 2015

This study examined the influence of implicit and explicit instruction for the acquisition of two types of Dutch spelling rules: a morphological and a phonological rule. A sample of 193 first grade, low- and high skilled spellers was assigned to an implicit-instruction, explicit-instruction, or control-group condition. The results showed that for both rules, students in the explicit condition made more progress than students in the control condition. For the morphological rule, students in the explicit condition had higher posttest scores on pseudo-words than students in the implicit condition. The effects of the three conditions were the same for low- and high-skilled spellers. Both low- and high-skilled spellers in the implicit and explicit condition did not fully generalize their knowledge of both rules to new and pseudo-words.
Orthographic constraints on the spelling of German a-sounds
Authors: Appelt Annalen , Balestra Miriam , Neef Martin
Published: February 2015

In the framework of the Modular Writing System Theory (Neef 2005a), two levels of representation are distinguished that are relevant for the analysis of phonographic writing systems. These levels are called graphematics and systematic orthography, respectively. In this text, we focus on the latter module. As a case study, we take into account the spelling potential of the German vowels [a] (lax) and [ɑ] (tense). For this purpose, we first discuss the graphematic properties of these two vowels which allows deriving their graphematic solution spaces that capture such spelling variants that are theoretically given in the writing system of German. Subsequently, we use the spelling potential of [a] and [ɑ] to investigate their distribution in the systematic orthography of German. In doing so, we formulate orthographic constraints that regulate the appearance of the spelling variants. These constraints are sensitive for different levels of the German vocabulary. Some of the constraints have already been found relevant for the spelling of other phonemes as well, while others are specific to the two sounds under consideration. This theoretical approach allows analyzing a much broader part of the vocabulary compared to other theories.
Epidemiology of tennis injuries: An eight‐year review of Davis Cup retirements
Authors: Maquirriain Javier , Baglione Roberto
Published: February 2015

Tennis practice, especially at elite levels, may place players at risk for debilitating musculoskeletal injuries. The aim of this study was to analyse the epidemiological pattern of retirements due to medical conditions sustained by tennis players during Davis Cup matches in the 2006–2013 period. All uncompleted matches due to a medical condition (injuries and illnesses) occurred in the above‐mentioned competition were collected from the official source, registered and analysed according to published guidelines. The overall incidence of match retirements was 1.66% (12/719). The injury rate was 6.05/1000 playing hours; and 6.64/1000 match exposures. Musculotendinous lesions were the most common type of injury (66.66%). The incidence of lower‐limb injuries was higher than upper‐limb and trunk lesions. The incidence of retired matches due to medical conditions was higher in hard courts than in clay courts (2.97% and 0.90%, respectively; p = 0.04), while the median value of inactivity of injuries was 32.0 days (range 3–297). In conclusion, the incidence of retirements due to medical conditions in Davis Cup matches was low supporting the assumption that elite tennis is a low‐risk sport activity. Findings provided scientific evidences of injury patterns among male professional tennis players and may contribute to conduct better injury prevention strategies.
Ad‐libitum drinking and performance during a 40‐km cycling time trial in the heat
Authors: Berkulo Meriam A. R. , Bol Susan , Levels Koen , Lamberts Robert P. , Daanen Hein A. M. , Noakes Timothy D.
Published: February 2015

The aim of this study was to investigate if drinking ad‐libitum can counteract potential negative effects of a hypohydrated start caused by fluid restriction during a 40‐km time trial (TT) in the heat. Twelve trained males performed one 40‐km cycling TT euhydrated (EU: no water during the TT) and two 40‐km cycling TTs hypohydrated. During one hypohydrated trial no fluid was ingested (HYPO), during the other trial ad‐libitum water ingestion was allowed (FLUID). Ambient temperature was 35.2 ± 0.2°C, relative humidity 51 ± 3% and airflow 7 m·s−1. Body mass (BM) was determined at the start of the test, and before and after the TT. During the TT, power output, heart rate (HR), gastrointestinal temperature, mean skin temperature, rating of perceived exertion (RPE), thermal sensation, thermal comfort and thirst sensation were measured. Prior to the start of the TT, BM was 1.2% lower in HYPO and FLUID compared to EU. During the TT, BM loss in FLUID was lower compared to EU and HYPO (1.0 ± 0.8%, 2.7 ± 0.2% and 2.6 ± 0.3%, respectively). Hydration status had no effect on power output (EU: 223 ± 32 W, HYPO: 217 ± 39 W, FLUID: 224 ± 35 W), HR, gastrointestinal temperature, mean skin temperature, RPE, thermal sensation and thermal comfort. Thirst sensation was higher in HYPO than in EU and FLUID. It was concluded that hypohydration did not adversely affect performance during a 40‐km cycling TT in the heat. Therefore, whether or not participants consumed fluid during exercise did not influence their TT performance.
Quantifying positional and temporal movement patterns in professional rugby union using global positioning system
Authors: Jones Marc R. , West Daniel J. , Crewther Blair T. , Cook Christian J. , Kilduff Liam P.
Published: February 2015

This study assessed the positional and temporal movement patterns of professional rugby union players during competition using global positioning system (GPS) units. GPS data were collected from 33 professional rugby players from 13 matches throughout the 2012–2013 season sampling at 10 Hz. Players wore GPS units from which information on distances, velocities, accelerations, exertion index, player load, contacts, sprinting and repeated high‐intensity efforts (RHIE) were derived. Data files from players who played over 60 min (n = 112) were separated into five positional groups (tight and loose forwards; half, inside and outside backs) for match analysis. A further comparison of temporal changes in movement patterns was also performed using data files from those who played full games (n = 71). Significant positional differences were found for movement characteristics during performance (P < 0.05). Results demonstrate that inside and outside backs have greatest high‐speed running demands; however, RHIE and contact demands are greatest in loose forwards during match play. Temporal analysis of all players displayed significant differences in player load, cruising and striding between halves, with measures of low‐ and high‐intensity movement and acceleration/deceleration significantly declining throughout each half. Our data demonstrate significant positional differences for a number of key movement variables which provide a greater understanding of positional requirements of performance. This in turn may be used to develop progressive position‐specific drills that elicit specific adaptations and provide objective measures of preparedness. Knowledge of performance changes may be used when developing drills and should be considered when monitoring and evaluating performance.
Neuromuscular, physiological and endocrine responses to a maximal speed training session in elite games players
Authors: Johnston Michael , Cook Christian J. , Crewther Blair T. , Drake David , Kilduff Liam P.
Published: February 2015

The aim of this study was to determine the acute neuromuscular, biochemical and endocrine responses to a maximal speed training (MST) session. Eighteen male rugby players completed the protocol, which involved performing six maximal effort repetitions of 50 m running sprints with 5 minutes recovery between each sprint. Testosterone (T), cortisol (C), creatine kinase (CK), lactate (La), perceived muscle soreness (MS) and counter movement jump were collected immediately pre (PRE), immediately post (IP), 2 hours post (2P) and 24 hours post (24P) the sprint session. A bimodal recovery pattern was observed from the jump parameters with several declining significantly (p ≤ 0.05) IP, recovering 2P and suffering a secondary decline 24P. CK and perceived MS were elevated IP and continued to rise throughout the protocol, while La was only elevated IP. T and C were unaffected IP but showed significant declines 2P. These data indicate that MST results in a bimodal recovery pattern of neuromuscular function with changes most likely being related to metabolic and biochemical responses.
Corrections and notes to “Value groups, residue fields and bad places of rational function fields”
Authors: Blaszczok Anna , Kuhlmann Franz-Viktor
Published: February 2015

We correct mistakes in a 2004 paper by the second author and report on recent new developments which settle cases left open in that paper.
Cytosolic chaperones mediate quality control of higher-order septin assembly in budding yeast
Authors: Johnson Courtney R. , Weems Andrew D. , Brewer Jennifer M. , Thorner Jeremy , McMurray Michael A.
Published: February 2015

Septin hetero-oligomers polymerize into cytoskeletal filaments with essential functions in many eukaryotic cell types. Mutations within the oligomerization interface that encompasses the GTP-binding pocket of a septin (its “G interface”) cause thermoinstability of yeast septin hetero-oligomer assembly, and human disease. When coexpressed with its wild-type counterpart, a G interface mutant is excluded from septin filaments, even at moderate temperatures. We show that this quality control mechanism is specific to G interface mutants, operates during de novo septin hetero-oligomer assembly, and requires specific cytosolic chaperones. Chaperone overexpression lowers the temperature permissive for proliferation of cells expressing a G interface mutant as the sole source of a given septin. Mutations that perturb the septin G interface retard release from these chaperones, imposing a kinetic delay on the availability of nascent septin molecules for higher-order assembly. Un­expectedly, the disaggregase Hsp104 contributes to this delay in a manner that does not require its “unfoldase” activity, indicating a latent “holdase” activity toward mutant septins. These findings provide new roles for chaperone-mediated kinetic partitioning of non-native proteins and may help explain the etiology of septin-linked human diseases.
An exposure-effect approach for evaluating ecosystem-wide risks from human activities
Authors: Knights Antony M. , Piet Gerjan J. , Jongbloed Ruud H. , Tamis Jacqueline E. , White Lydia , Akoglu Ekin , Boicenco Laura , Churilova Tanya , Kryvenko Olga , Fleming-Lehtinen Vivi , Leppanen Juha-Markku , Galil Bella S. , Goodsir Freya , Goren Menachem , Margonski Piotr , Moncheva Snejana , Oguz Temel , Papadopoulou K. Nadia , Setälä Outi , Smith Chris J. , Stefanova Kremena , Timofte Florin , Robinson Leonie A.
Published: February 2015

Ecosystem-based management (EBM) is promoted as the solution for sustainable use. An ecosystem-wide assessment methodology is therefore required. In this paper, we present an approach to assess the risk to ecosystem components from human activities common to marine and coastal ecosystems. We build on: (i) a linkage framework that describes how human activities can impact the ecosystem through pressures, and (ii) a qualitative expert judgement assessment of impact chains describing the exposure and sensitivity of ecological components to those activities. Using case study examples applied at European regional sea scale, we evaluate the risk of an adverse ecological impact from current human activities to a suite of ecological components and, once impacted, the time required for recovery to pre-impact conditions should those activities subside. Grouping impact chains by sectors, pressure type, or ecological components enabled impact risks and recovery times to be identified, supporting resource managers in their efforts to prioritize threats for management, identify most at-risk components, and generate time frames for ecosystem recovery.
Countertransference in End-of-Life Music Therapy
Authors: Wilkerson Anne , Dimaio Lauren , Sato Yumiko
Published: February 2015

Countertransference is a complex and important issue for end-of-life music therapists. However, limited literature is available on the subject of end-of-life music therapy and countertransference to guide professionals as we encounter the effects of countertransference inside and outside sessions. There are circumstances associated with end-of-life music therapy that require a closer look, that demand recognition, and that may result in better music experiences for our clients. The purpose of this article is to explore the experiences and influences of countertransference in the unique situations presented by end-of-life music therapy, thus increasing readers’ awareness of the potential impact of countertransference upon their clinical practices.
The Stringent Response Mediated by (p)ppGpp Is Required for Virulence ofPseudomonas syringaepv.tomatoand Its Survival on Tomato
Authors: Chatnaparat Tiyakhon , Li Zhong , Korban Schuyler S. , Zhao Youfu
Published: February 2015

The hypersensitive response and pathogenicity (hrp) type III secretion system (T3SS) is a key pathogenicity factor in Pseudomonas syringae pv. tomato DC3000 (DC3000). In this study, the role of the second messenger (p)ppGpp on virulence and survival of DC3000 was investigated. Results have demonstrated that (p)ppGpp-deficient mutant (ppGpp0) of DC3000 exhibited lower levels of expression of the T3SS and genes of other virulence traits, such as coronatine toxin. The ppGpp0mutant of DC3000 was greatly impaired in causing disease and in growth in planta. Furthermore, (p)ppGpp was required for swarming motility, pyoverdine production, the oxidative stress response, as well as γ-amino butyric acid utilization. Screening of amino acids, major signals in activation of ppGpp biosynthesis, revealed that promoter activities of the avrPto gene could be either activated or suppressed by various amino acids in a ppGpp-dependent or -independent manner. Moreover, the ppGpp0mutant exhibited increased cell size and decreased survival on plant surfaces. Altogether, these findings indicate that ppGpp acts as an internal signal that regulates the T3SS as well as other virulence factors in pseudomonads and suggest that bacterial pathogens utilize intracellular messengers to sense environmental and nutritional signals for rapid, precise, and reversible control of their pathogenesis and survival.
A Multiplex qPCR Assay for Detection and Quantification of Plasmodiophora brassicae in Soil
Authors: Deora Abhinandan , Gossen Bruce D. , Amirsadeghi Sasan , McDonald Mary Ruth
Published: February 2015

Various physical and chemical factors in soil can inhibit the detection and quantification of soilborne plant pathogens using quantitative polymerase chain reaction (qPCR) assays. A multiplexed TaqMan qPCR assay, including a competitive internal positive control (CIPC), was developed to identify and (where necessary) compensate for inhibition in the quantification of resting spores of Plasmodiophora brassicae from soil. The CIPC amplicon was developed by modifying a sequence coding for green fluorescent protein so that it could be amplified with P. brassicae-specific primers. Addition of CIPC at 5 fg/μl to the singleplex qPCR assay designed to quantify P. brassicae genomic DNA did not reduce the sensitivity, specificity, or reproducibility of the assay. Each of the soil samples, either artificially inoculated or naturally infested with P. brassicae, exhibited no amplification of the CIPC. When the samples were diluted and reassessed, the quantification cycle of the CIPC relative to the control (water only) was delayed in each sample. The magnitude of the delay was used to adjust the estimate of resting spore concentration. The corrected concentration estimates were significantly higher than the unadjusted estimate, which indicated the presence of DNA inhibitors in samples even after dilution. The only exception was a mineral soil sample inoculated with a low concentration (103 spores/g) of resting spores. The assay was optimized for use on a range of soil types. A sample of 0.25 g for mineral soil and 0.10 g for high-organic-matter soil was optimum for recovery of DNA of P. brassicae. The assay represents an improvement over existing assays for estimating resting spore concentration in infested fields.
Monilinia spp. Causing Brown Rot of Stone Fruit in Serbia
Authors: Hrustić Jovana , Delibašić Goran , Stanković Ivana , Grahovac Mila , Krstić Branka , Bulajić Aleksandra , Tanović Brankica
Published: February 2015

Brown rot is one of the most important pre- and postharvest fungal diseases of stone fruit worldwide. In Serbia, where production of stone fruit is economically important, Monilinia laxa and M. fructigena are widely distributed. In surveys from 2011 to 2013, 288 isolates of Monilinia spp. were collected from 131 localities in 16 districts and from six hosts in Serbia. Using multiplex polymerase chain reaction, phylogenetic analysis, and morphological characterization, three species of Monilinia were identified as the causal agents of brown rot of stone fruit: M. laxa (89% of isolates), M. fructigena (3%), and M. fructicola (8%). In 2011, M. fructicola was reported for the first time on stone fruit in Serbia, with only one isolate detected. More isolates of M. fructicola were detected in 2012 (2 isolates) and 2013 (20 isolates). The presence of M. fructicola, as well as its increased frequency of detection during the survey, may indicate a change in the population structure of these pathogens, which could have an important impact on brown rot disease management in Serbia.