bluuebunny/crossref_metadata_2025 huggingface dataset:
A nonlinear eigenvalue problem for self-similar spherical force-free magnetic fields
Authors: Lerche I. , Low B. C.
Published: October 2014

An axisymmetric force-free magnetic field B(r, θ) in spherical coordinates is defined by a function r sin θBφ=Q(A) relating its azimuthal component to its poloidal flux-function A. The power law r sin θBφ=aA|A|1/n, n a positive constant, admits separable fields with A=An(θ)rn, posing a nonlinear boundary-value problem for the constant parameter a as an eigenvalue and An(θ) as its eigenfunction [B. C. Low and Y. Q Lou, Astrophys. J. 352, 343 (1990)]. A complete analysis is presented of the eigenvalue spectrum for a given n, providing a unified understanding of the eigenfunctions and the physical relationship between the field's degree of multi-polarity and rate of radial decay via the parameter n. These force-free fields, self-similar on spheres of constant r, have basic astrophysical applications. As explicit solutions they have, over the years, served as standard benchmarks for testing 3D numerical codes developed to compute general force-free fields in the solar corona. The study presented includes a set of illustrative multipolar field solutions to address the magnetohydrodynamics (MHD) issues underlying the observation that the solar corona has a statistical preference for negative and positive magnetic helicities in its northern and southern hemispheres, respectively; a hemispherical effect, unchanging as the Sun's global field reverses polarity in successive eleven-year cycles. Generalizing these force-free fields to the separable form B=H(θ,φ)rn+2 promises field solutions of even richer topological varieties but allowing for φ-dependence greatly complicates the governing equations that have remained intractable. The axisymmetric results obtained are discussed in relation to this generalization and the Parker Magnetostatic Theorem. The axisymmetric solutions are mathematically related to a family of 3D time-dependent ideal MHD solutions for a polytropic fluid of index γ = 4/3 as discussed in the Appendix.
Cobalt ferrite sphere-coated buckhorn-like barium titanate: Fabrication, characterization, its dielectric resonance, and microwave attenuation properties
Authors: Ji Renlong , Cao Chuanbao
Published: October 2014

Barium titanate (BTO) with different morphology is prepared through hydrothermal method using titania spheres as precursor, then calcined at different temperatures and ultimately coated with cobalt ferrite (BTO/CFO). The dielectric dispersion of the composite containing BTO (75 wt. % ratio in paraffin wax) shows evidence of resonance behaviour in the microwave spectrum, rather than the usually observed relaxation mode. The imaginary part of permittivity (ε″) displays a strong peak in the 10–13 GHz frequency region, especially for buckhorn-like BTO (hydrothermally synthesized at 110 °C and calcined at 1100 °C). The dielectric response anomaly of BTO in special morphology is due to the emission of plane acoustic waves caused by electrostrictive and converse piezoelectric effects. An accepted model is adopted to simulate the resonance frequency. The minimum reflection loss of cauliflower-like BTO (hydrothermally synthesized at 110 °C, then calcined at 600 °C for 2 h, 75 wt. % ratio) in paraffin wax reaches −30.831 dB at 10.56 GHz with a matching thickness of 2 mm, lower than all the reported values. When the sintering temperature is changed to 1100 °C (buckhorn-like BTO), the minimum reflection loss value is −24.37 dB at 12.56 GHz under the thickness of 3 mm. After combination with CFO, the value reaches −42.677 dB when the thickness is 5.6 mm. The ginger-like BTO (hydrothermally synthesized at 200 °C and calcined at different temperatures) is inferior in microwave reflection reduction. The electromagnetic interference shielding effectiveness of buckhorn-like BTO composite is calculated to be −12.7 dB (94.6% shielding) at resonance frequency (2 mm, 11.52 GHz). This work clearly shows the potential to tune the dielectric property of ferroelectrics through control of morphology, facilitating new comprehension of the ferroelectrics in microwave regime.
Mixed quantal-semiquantal dynamics with stochastic particles for backreaction
Authors: Ando Koji
Published: October 2014

A mixed quantal-semiquantal theory is presented in which the semiquantal squeezed-state wave packet describes the heavy degrees of freedom. Starting from the mean-field equations of motion that are naturally derived from the time-dependent variational principle, we introduce the stochastic particle description for both the quantal and semiquantal parts in an aim to take into account the interparticle correlation, in particular the “quantum backreaction” beyond the mean-field approximation. A numerical application on a model of O2 scattering from a Pt surface demonstrates that the proposed scheme gives correct asymptotic behavior of the scattering probability, with improvement over the mixed quantum-classical scheme with Bohmian particles, which is comprehended by comparing the Bohmian and the stochastic trajectories.
Intrinsic carrier mobility of Dirac cones: The limitations of deformation potential theory
Authors: Li Zhenzhu , Wang Jinying , Liu Zhirong
Published: October 2014

An analytic formula for the intrinsic carrier mobility of Dirac cones under acoustic phonon scattering conditions was obtained for 2D systems such as graphene and graphyne. The influences of both the transverse acoustic (TA) and longitudinal acoustic phonon modes and that of the anisotropy were considered. Some extraordinary characteristics unlike those predicted by the deformation potential theory were revealed: the mobility at the neutrality point is proportional to 1/T3, where T is the temperature; also, carrier scattering by the TA phonons dominates the mobility of graphene, which explains the overestimation of the measured deformation potential of graphene in previous experiments. The theory was combined with first-principles calculations to determine the mobility of graphene and five graphynes with Dirac cones. It was predicted that most graphynes will have much higher mobility than graphene because of the suppression of the scattering by the TA phonons.
Effects of the aluminum content on the shock wave pressure and the acceleration ability of RDX-based aluminized explosives
Authors: Zhou Z. Q. , Nie J. X. , Ou Z. C. , Qin J. F. , Jiao Q. J.
Published: October 2014

To better understand the influence of the aluminum content on the performance of aluminized explosives, experiments in concrete and cylinder tests were performed. Three types of RDX-based aluminized explosives, in which the mass ratio of aluminum content was 0%, 15%, and 30% were considered in this paper. The shock wave pressures of the aluminized explosives in the affected concrete bodies were measured using manganin pressure sensors. The acceleration ability was obtained using a high-speed camera and a rotating mirror streak camera. The peak pressure attenuation characteristics of the explosives with various aluminum contents indicated that a higher aluminum content is associated with a slower peak pressure attenuation of the shock wave. In addition, the results of the cylinder tests and the metal-rod acceleration tests revealed the influence of the aluminum content on the acceleration ability of explosives in three different time periods. The test data presented in this paper verified the relationship between the aluminum content and explosive performance, which is of great significance for optimizing the properties of aluminized explosives.
Beam-loaded frequency shift study in an over-sized backward wave oscillator
Authors: Li Zhenghong , Zhou Zhigang , Qiu Rong
Published: October 2014

The oversized backward wave oscillator (BWO) can significantly decreases the internal rf electric field in the device. The beam-loaded effect is obvious in such devices and its performance is also significantly affected. Based on the characteristics of the oversized BWO, a self-consistent equation is developed to study its beam-loaded frequency shift together with particle in cell (PIC) simulations. The mechanism whereby the output rf frequency is affected by the beam's parameters and the device's structure is theoretically studied. The frequency's dependence on the drift tube length between the reflector and SWS (slow wave structures) in the device is deduced in the paper and the theoretical results agree with those obtained in PIC simulations.
Modeling and simulation of grid connected solid oxide fuel cell using PSCAD
Authors: Fedakar S. , Bahceci S. , Yalcinoz T.
Published: October 2014

Solid oxide fuel cell (SOFC) is being developed for a wide variety of applications because of their high efficiency, reliability, and fuel adaptability. In this paper, a grid connected SOFC system is presented by using PSCAD software. The power conditioning unit (PCU) is used for simulation studies and also the transformer is used for electrical isolation. The simulation studies of the SOFC dynamic model are investigated for three case studies. In the first simulation study, the SOFC dynamic model is connected to constant and variable DC loads without PCU. The second simulation study is performed for three phase AC load conditions. The AC performance of SOFC is tested under an AC load through the transmission line of 400 V at the length of 10 km. The last simulation study is implemented for the grid connected SOFC system. In the grid connected case study, a three bus system, which includes an infinite bus, a load bus and a fuel cell bus, is formed under AC load conditions. The results show the fast response capabilities of the grid connected SOFC system in different case studies and various load types.
High pressure induced phase transition and superdiffusion in anomalous fluid confined in flexible nanopores
Authors: Bordin José Rafael , Krott Leandro B. , Barbosa Marcia C.
Published: October 2014

The behavior of a confined spherical symmetric anomalous fluid under high external pressure was studied with Molecular Dynamics simulations. The fluid is modeled by a core-softened potential with two characteristic length scales, which in bulk reproduces the dynamical, thermodynamical, and structural anomalous behavior observed for water and other anomalous fluids. Our findings show that this system has a superdiffusion regime for sufficient high pressure and low temperature. As well, our results indicate that this superdiffusive regime is strongly related with the fluid structural properties and the superdiffusion to diffusion transition is a first order phase transition. We show how the simulation time and statistics are important to obtain the correct dynamical behavior of the confined fluid. Our results are discussed on the basis of the two length scales.
Valley-dependent spin polarization and long-lived electron spins in germanium
Authors: Giorgioni Anna , Vitiello Elisa , Grilli Emanuele , Guzzi Mario , Pezzoli Fabio
Published: October 2014

Spin orientation and relaxation of conduction band electrons in bulk Ge are addressed by studying the steady-state circular polarization of the indirect gap photoluminescence (PL) at low temperatures. This provides a direct experimental proof of recently predicted spin-dependent selection rules for phonon-mediated optical transitions in Ge. In addition, we observe valley-dependent circularly polarized emission, and map the concomitant redistribution of electron spins within the multi-valley conduction band of Ge by gaining simultaneous access to the circular dichroism of light emitted across the direct and the indirect gap transitions. Finally, the lifetime of L-valley electrons is measured by means of decay curves of the indirect gap PL emission, yielding spin relaxation times in the order of hundreds of ns.
Modulation bandwidth of spin torque oscillators under current modulation
Authors: Quinsat M. , Garcia-Sanchez F. , Jenkins A. S. , Tiberkevich V. S. , Slavin A. N. , Buda-Prejbeanu L. D. , Zeltser A. , Katine J. A. , Dieny B. , Cyrille M.-C. , Ebels U.
Published: October 2014

For practical applications of spin torque nano-oscillators (STNO), one of the most critical characteristics is the speed at which an STNO responds to variations of external control parameters, such as current or/and field. Theory predicts that this speed is limited by the amplitude relaxation rate Γp that determines the timescale over which the amplitude fluctuations are damped out. In this study, this limit is verified experimentally by analyzing the amplitude and frequency noise spectra of the output voltage signal when modulating an STNO by a microwave current. In particular, it is shown that due to the non-isochronous nature of the STNO the amplitude relaxation rate Γp determines not only the bandwidth of an amplitude modulation, but also the bandwidth of a frequency modulation. The presented experimental technique will be important for the optimisation of the STNO characteristics for applications in telecommunications or/and data storage and is applicable even in the case when the STNO output signal is only several times higher than noise.
How do evaporating thin films evolve? Unravelling phase-separation mechanisms during solvent-based fabrication of polymer blends
Authors: Wodo Olga , Ganapathysubramanian Baskar
Published: October 2014

Solvent-based fabrication is a flexible and affordable approach to manufacture polymer thin films. The properties of products made from such films can be tailored by the internal organization (morphology) of the films. However, a precise knowledge of morphology evolution leading to the final film structure remains elusive, thus limiting morphology control to a trial and error approach. In particular, understanding when and where phases are formed, and how they evolve would provide rational guidelines for more rigorous control. Here, we identify four modes of phase formation and subsequent propagation within the thinning film during solvent-based fabrication. We unravel the origin and propagation characteristics of each of these modes. Finally, we construct a mode diagram that maps processing conditions with individual modes. The idea introduced here enables choosing processing conditions to tailor film morphology characteristics and paves the ground for a deeper understanding of morphology control with the ultimate goal of precise, yet affordable, morphology manipulation for a large spectrum of applications.
Spin depolarization under low electric fields at low temperatures in undoped InGaAs/AlGaAs multiple quantum well
Authors: Zhu Laipan , Liu Yu , Jiang Chongyun , Yu Jinling , Gao Hansong , Ma Hui , Qin Xudong , Li Yuan , Wu Qing , Chen Yonghai
Published: October 2014

The spin polarization under low electric fields (≤300 V/cm) at low temperatures has been studied in undoped InGaAs/AlGaAs multiple quantum well. The spin polarization was created by optical spin orientation using circularly polarized light and the inverse spin-Hall effect was employed to measure the spin polarization current. We observed an obvious spin depolarization especially at lower temperatures (80–120 K). We ascribed the spin depolarization of the photoinduced electrons to the heating effect from the low electric fields (the low field regime 50–300 V/cm). This spin depolarization due to the heating effect is sensitive to temperature and electric field, suggesting a wide range of potential applications and devices.
Exchange bias field induced symmetry-breaking of magnetization rotation in two-dimension
Authors: Cui B. , Song C. , Sun Y. , Wang Y. Y. , Zhao Y. L. , Li F. , Wang G. Y. , Zeng F. , Pan F.
Published: October 2014

We investigate the effect of strain-induced intrinsic exchange bias field (HEB) on the magnetization rotation process in a nominally “single” layered La2/3Sr1/3MnO3 (LSMO) film. The intrinsic exchange bias appears when the LSMO film is grown on LaAlO3 substrate. The HEB is proved to be an effective approach to tuning the in-plane magnetization rotation, producing a 360° instead of 180° periodicity in the anisotropic magnetoresistance curves measured in a low external magnetic field. The planar Hall effect curves are asymmetric when the in-plane magnetization rotate between two orthogonal axes of LSMO, helped or hindered by the HEB. Our study reveals that the HEB in but not limited to LSMO with phase separation exhibits an unprecedentedly two-dimensional effect rather than merely establishing a reference magnetization direction as achieved in ferromagnetic/antiferromagnetic bilayers, thus furthering the cognition of manipulating the magnetization orientation.
Clustering methods of wind turbines and its application in short-term wind power forecasts
Authors: Liu Yongqian , Gao Xiaoli , Yan Jie , Han Shuang , Infield David G.
Published: October 2014

Commonly used wind power forecasts methods choose only one representative wind turbine to forecast the output power of the entire wind farm; however, this approach may reduce the forecasting accuracy. If each wind turbine in a wind farm is forecasted individually, this considerably increases the computational cost, especially for a large wind farm. In this work, a compromise approach is developed where the turbines in the wind farm are clustered and a forecast made for each cluster. Three clustering methods are evaluated: K-means; a self-organizing map (SOM); and spectral clustering (SC). At first, wind turbines in a wind farm are clustered into several groups by identifying similar characteristics of wind speed and output power. Sihouette coefficient and Hopkins statistics indices are adopted to determine the optimal cluster number which is an important parameter in cluster analysis. Next, forecasting models of the selected representative wind turbines for each cluster based on correlation analysis are established separately. A comparative study of the forecast effect is carried to determine the most effective clustering method. Results show that the short-term wind power forecasting on the basis of SOM and SC clustering are effective to forecast the output power of the entire wind farm with better accuracy, respectively, 1.67% and 1.43% than the forecasts using a single wind speed or power to represent the wind farm. Both Hopkins statistics and Sihouette coefficient are effective in choosing the optimal number of clusters. In addition, SOM with its higher forecast accuracy and SC with more efficient calculation when applied into wind power forecasts can provide guidance for the operating and dispatching of wind power. The emphasis of the paper is on the clustering methods and its effect applied in wind power forecasts but not the forecasting algorithms.
Nonlinear optical spectra having characteristics of Fano interferences in coherently coupled lowest exciton biexciton states in semiconductor quantum dots
Authors: Gotoh Hideki , Sanada Haruki , Yamaguchi Hiroshi , Sogawa Tetsuomi
Published: October 2014

Optical nonlinear effects are examined using a two-color micro-photoluminescence (micro-PL) method in a coherently coupled exciton-biexciton system in a single quantum dot (QD). PL and photoluminescence excitation spectroscopy (PLE) are employed to measure the absorption spectra of the exciton and biexciton states. PLE for Stokes and anti-Stokes PL enables us to clarify the nonlinear optical absorption properties in the lowest exciton and biexciton states. The nonlinear absorption spectra for excitons exhibit asymmetric shapes with peak and dip structures, and provide a distinct contrast to the symmetric dip structures of conventional nonlinear spectra. Theoretical analyses with a density matrix method indicate that the nonlinear spectra are caused not by a simple coherent interaction between the exciton and biexciton states but by coupling effects among exciton, biexciton and continuum states. These results indicate that Fano quantum interference effects appear in exciton-biexciton systems at QDs and offer important insights into their physics.
Near-infrared emission from mesoporous crystalline germanium
Authors: Boucherif Abderraouf , Korinek Andreas , Aimez Vincent , Arès Richard
Published: October 2014

Mesoporous crystalline germanium was fabricated by bipolar electrochemical etching of Ge wafer in HF-based electrolyte. It yields uniform mesoporous germanium layers composed of high density of crystallites with an average size 5-7 nm. Subsequent extended chemical etching allows tuning of crystallites size while preserving the same chemical composition. This highly controllable nanostructure exhibits photoluminescence emission above the bulk Ge bandgap, in the near-infrared range (1095-1360nm) with strong evidence of quantum confinement within the crystallites.
The evolution and evaluation of dairy cattle models for predicting milk production: an agricultural model intercomparison and improvement project (AgMIP) for livestock
Authors: Tedeschi Luis O. , Cavalcanti Luigi F. L. , Fonseca Mozart A. , Herrero Mario , Thornton Phillip K.
Published: October 2014

The contemporary concern about anthropogenic release of greenhouse gas (GHG) into the environment and the contribution of livestock to this phenomenon have sparked animal scientists’ interest in predicting methane (CH4) emissions by ruminants. We contend that improving the adequacy of mathematical nutrition model estimates of production of meat and milk is a sine qua non condition to reliably determine ruminants’ worldwide contribution to GHG. Focusing on milk production, we address six basic nutrition models or feeding standards (mostly empirical systems) and five complex nutrition models (mostly mechanistic systems), describe their key characteristics, and highlight their similarities and differences. We also present derivative systems. We compiled a database of milk production information from 37 published studies from six regions of the world, totalling 173 data points: 19 for Africa, 45 for Asia, 16 for Europe, 12 for Latin America, 44 for North America and 37 for Oceania. Four models were used to predict milk production in lactating dairy cows, and the adequacy of their predictions was measured against the observed milk production from our database. Even though these mathematical nutrition models shared similar assumptions and calculations, they have different conceptual and structural foundations inherent to their intended purposes. A direct comparison among these models was further complicated by the different models requiring unique inputs that are very often not available, and the low reliability of the inputs prevents an unbiased assessment of the model predictions. Very few studies have collected the necessary information to run more mechanistic systems, and users have to rely on standard information to populate many model inputs. Study effect was a critical source of variation that limited our ability to conclusively evaluate the models’ applicability under different scenarios of production around the world. Only after study variation was removed from the database did the adequacy of the model predictions of milk production improved, but deficiencies still existed. On the basis of these analyses, we conclude that not all models were suitable for predicting milk production and that simpler systems might be more resilient to variations in studies and production conditions around the world. Improving the predictability of milk production by mathematical nutrition models is a prerequisite to further development of systems that can effectively and correctly estimate the contribution of ruminants to GHG emissions and their true share of the global warming event.
Direct activation of RIP3/MLKL-dependent necrosis by herpes simplex virus 1 (HSV-1) protein ICP6 triggers host antiviral defense
Authors: Wang Xing , Li Yun , Liu Shan , Yu Xiaoliang , Li Lin , Shi Cuilin , He Wenhui , Li Jun , Xu Lei , Hu Zhilin , Yu Lu , Yang Zhongxu , Chen Qin , Ge Lin , Zhang Zili , Zhou Biqi , Jiang Xuejun , Chen She , He Sudan
Published: October 2014

Significance

Receptor-interacting kinase-3 (RIP3) and its substrate mixed lineage kinase domain-like protein (MLKL) are now recognized as the core cellular regulators of programmed necrosis. Programmed necrosis is thought be involved in host defense against pathogens, but the mechanistic studies on the topic are still scarce. We discover that human herpes simplex virus 1 (HSV-1) triggers RIP3/MLKL-dependent necrosis in host cells. HSV-1 ribonucleotide reductase large subunit (ICP6) is found to be a direct activator of RIP3 and sufficient for triggering programmed necrosis. Mice lacking RIP3 exhibited severely impaired control of HSV-1 replication and pathogenesis. This study provides a clear case how host cells use programmed necrosis to mount an antiviral response.
The iron content and ferritin contribution in fresh, dried, and toasted nori, Pyropia yezoensis
Authors: Masuda Taro , Yamamoto Ami , Toyohara Haruhiko
Published: October 2014

Iron is one of the essential trace elements for humans. In this study, the iron contents in fresh, dried, and toasted nori (Pyropia yezoensis) were analyzed. The mean iron content of fresh, dried, and toasted nori were 19.0, 22.6, and 26.2 mg/100 g (dry weight), respectively. These values were superior to other food of plant origin. Furthermore, most of the iron in nori was maintained during processing, such as washing, drying, and toasting. Then, the form of iron in fresh, dried, and toasted nori was analyzed. As a result, an iron storage protein ferritin contributed to iron storage in raw and dried nori, although the precise rate of its contribution is yet to be determined, while ferritin protein cage was degraded in the toasted nori. It is the first report that verified the ferritin contribution to iron storage in such edible macroalgae with commercial importance.
SNPsnap: a Web-based tool for identification and annotation of matched SNPs
Authors: Pers Tune H. , Timshel Pascal , Hirschhorn Joel N.
Published: October 2014

Summary: An important computational step following genome-wide association studies (GWAS) is to assess whether disease or trait-associated single-nucleotide polymorphisms (SNPs) enrich for particular biological annotations. SNP-based enrichment analysis needs to account for biases such as co-localization of GWAS signals to gene-dense and high linkage disequilibrium (LD) regions, and correlations of gene size, location and function. The SNPsnap Web server enables SNP-based enrichment analysis by providing matched sets of SNPs that can be used to calibrate background expectations. Specifically, SNPsnap efficiently identifies sets of randomly drawn SNPs that are matched to a set of query SNPs based on allele frequency, number of SNPs in LD, distance to nearest gene and gene density.

Availability and implementation: SNPsnap server is available at http://www.broadinstitute.org/mpg/snpsnap/ .

Contact:  joelh@broadinstitute.org

Supplementary information:  Supplementary data are available at Bioinformatics online.
Repeatability Precision of the Falling Number Procedure Under Standard and Modified Methodologies
Authors: Delwiche Stephen R. , Vinyard Bryan T. , Bettge Arthur D.
Published: October 2014

The falling number (FN) procedure is used worldwide to assess the integrity of the starch stored within wheat seed. As an indirect measurement of the activity level of α‐amylase, FN relies on a dedicated viscometer that measures the amount of time needed for a metal stirring rod of precise geometry to descend a fixed distance through a column of water–flour or water–meal slurry that undergoes enzyme‐activated starch hydrolysis under controlled mixing and heating conditions. For U.S. wheat, FN values of 300 s and above generally indicate soundness in the condition of the seed starches, whereas values less than 300 s often indicate that some seeds have broken dormancy, which deleteriously affects bread‐, cake‐, and noodle‐making quality of products derived from their flour. Domestic and especially overseas sales contracts will often specify a minimum FN value for consignments, thus making it critical to ensure that the FN procedure be highly precise. The study described herein examined the level of repeatability precision of the FN procedure under strictly controlled laboratory conditions as a means to establish precision levels arising alone from the random nature of the viscous properties of starchy meal undergoing mixing and heating. Six representative samples of Pacific Northwest–grown soft white and club wheat, ranging in FN between 168 and 404 s, were repeatedly measured with the conventional FN procedure and three modifications thereof, with the modifications being increased meal and water amounts (8 g of meal + 30 mL of H2O instead of 7 g + 25 mL) or the addition of a polysorbate surfactant (0.1% Tween 20) to the mixture water. Based on 16 FN runs for each sample and treatment, estimated variances and coefficients of variation (CV) were determined for each treatment–sample combination. The results indicated that CVs between 1 and 4% were achieved for all treatments and samples. The treatment modification of an augmented test sample size improved precision, whereas incorporating a surfactant had a negligible effect. Precision and treatment (conventional versus augmented) findings were corroborated by two external laboratories with two of the six original samples and by the main laboratory on an independent set of 14 wheat meal samples of commercial origin. Another possible improvement in precision is in the sequencing of water and meal addition to be half the volume of water, then the meal, followed by the remaining volume of water, all at the conventional levels of meal and water. Preliminary experimental results indicate an improvement in precision by using the “sandwich” approach; however, further testing is warranted to substantiate this discovery.
Multiple Roles and Effects of a NovelTrichodermaHydrophobin
Authors: Ruocco Michelina , Lanzuise Stefania , Lombardi Nadia , Woo Sheridan L. , Vinale Francesco , Marra Roberta , Varlese Rosaria , Manganiello Gelsomina , Pascale Alberto , Scala Valeria , Turrà David , Scala Felice , Lorito Matteo
Published: October 2014

Fungi belonging to the genus Trichoderma are among the most active and ecologically successful microbes found in natural environments, because they are able to use a variety of substrates and affect the growth of other microbes and virtually any plant species. We isolated and characterized a novel type II hydrophobin secreted by the biocontrol strain MK1 of Trichoderma longibrachiatum. The corresponding gene (Hytlo1) has a multiple role in the Trichoderma–plant–pathogen three-way interaction, while the purified protein displayed a direct antifungal as well as a microbe-associated molecular pattern and a plant growth promotion (PGP) activity. Leaf infiltration with the hydrophobin systemically increased resistance to pathogens and activated defense-related responses involving reactive oxygen species, superoxide dismutase, oxylipin, phytoalexin, and pathogenesis-related protein formation or activity. The hydrophobin was found to enhance development of a variety of plants when applied at very low doses. It particularly stimulated root formation and growth, as demonstrated also by transient expression of the encoding gene in tobacco and tomato. Targeted knock-out of Hytlo1 significantly reduced both antagonistic and PGP effect of the wild-type strain. We conclude that this protein represents a clear example of a molecular factor developed by Trichoderma spp. to establish a mutually beneficial interaction with the colonized plant.
Intraspecific Root Grafts and Clonal Growth Within Ailanthus altissima Stands Influence Verticillium nonalfalfae Transmission
Authors: O’Neal E. S. , Davis D. D.
Published: October 2014

Verticillium nonalfalfae, causal agent of Verticillium wilt, is being considered as a biocontrol for the highly invasive Ailanthus altissima in Pennsylvania. This soilborne fungus is extremely virulent on Ailanthus and rapidly transmitted from diseased to healthy trees within Ailanthus stands. The rapid transmission of the fungus could be facilitated by root grafts, but neither root graft formation in Ailanthus nor Verticillium transmission by root grafts in trees has been reported. Here, V. nonalfalfae transmission between diseased and healthy Ailanthus trees via intraspecific root grafts and clonal growth is evaluated. Using air-spade excavation, dye translocation, and root graft inoculations, functional root grafts were detected between Ailanthus trees and transmission of V. nonalfalfae across root grafts demonstrated. Inoculation of one Ailanthus parent stem resulted in 187 root sprouts showing Verticillium wilt symptoms 12 months after inoculation. This study revealed that clonal growth and root grafts, normally advantageous growth habits, leave Ailanthus stands vulnerable to widespread V. nonalfalfae infection. This study also broadens the understanding of the Ailanthus-Verticillium pathosystem, growth strategies of invasive Ailanthus, and epidemiology of Verticillium wilt within trees.
Emergence ofGroundnut ringspot virusandTomato chlorotic spot virusin Vegetables in Florida and the Southeastern United States
Authors: Webster Craig G. , Frantz Galen , Reitz Stuart R. , Funderburk Joseph E. , Mellinger H. Charles , McAvoy Eugene , Turechek William W. , Marshall Spencer H. , Tantiwanich Yaowapa , McGrath Margaret T. , Daughtrey Margery L. , Adkins Scott
Published: October 2014

Groundnut ringspot virus (GRSV) and Tomato chlorotic spot virus (TCSV) are two emerging tospoviruses in Florida. In a survey of the southeastern United States, GRSV and TCSV were frequently detected in solanaceous crops and weeds with tospovirus-like symptoms in south Florida, and occurred sympatrically with Tomato spotted wilt virus (TSWV) in tomato and pepper in south Florida. TSWV was the only tospovirus detected in other survey locations, with the exceptions of GRSV from tomato (Solanum lycopersicum) in South Carolina and New York, both of which are first reports. Impatiens (Impatiens walleriana) and lettuce (Lactuca sativa) were the only non-solanaceous GRSV and/or TCSV hosts identified in experimental host range studies. Little genetic diversity was observed in GRSV and TCSV sequences, likely due to the recent introductions of both viruses. All GRSV isolates characterized were reassortants with the TCSV M RNA. In laboratory transmission studies, Frankliniella schultzei was a more efficient vector of GRSV than F. occidentalis. TCSV was acquired more efficiently than GRSV by F. occidentalis but upon acquisition, transmission frequencies were similar. Further spread of GRSV and TCSV in the United States is possible and detection of mixed infections highlights the opportunity for additional reassortment of tospovirus genomic RNAs.
Canaloplasty in Open-angle Glaucoma: Mid-term Results From a Multicenter Study
Authors: Brusini Paolo , Caramello Guido , Benedetti Stefano , Tosoni Claudia
Published: October 2014

Purpose:

To present the mid-term results of a prospective multicenter study on canaloplasty surgery in chronic open-angle glaucoma.

Materials and Methods:

A total of 218 eyes from 197 patients with open-angle glaucoma under maximum tolerated medical therapy underwent canaloplasty within a time period of 42 months in 3 different Italian eye centers. All patients underwent a complete ophthalmic examination every 6 months. The follow-up ranged from 3 to 42 months.

Results:

The entire procedure according to standard protocol could not be performed in 20 eyes (9.2%). A total of 198 eyes from 178 patients with a mean follow-up of 23.1±10.6 months were taken into consideration. The preoperative mean intraocular pressure (IOP) was 28.4±7.5 mm Hg. The mean IOP at the 2-year follow-up was 15.9±4.7 mm Hg (range, 6 to 40 mm Hg; paired t test; P=0.0001), with a mean reduction from baseline of 44% (range, 11.1% to 82.8%). After 2 years of follow-up, a qualified success rate based on postoperative IOP≤21, ≤18, and ≤16 mm Hg was obtained in 82 (92.1%), 75 (84.3%), and 61 (68.5%) eyes, respectively; a complete success for an IOP≤21, ≤18, and ≤16 mm Hg was obtained in 63 (70.8%), 60 (67.4%), and 53 (59.5%) eyes, respectively. The number of medications used preoperatively and at the 2-year follow-up was 3.2±0.9 and 1.1±1.3, respectively. The most frequently seen complications included: hyphema in 47 eyes (23.7%), Descemet membrane detachment in 11 eyes (5.5%), and IOP spikes >10 mm Hg in 12 cases (6.1%).

Conclusions:

Canaloplasty is a quite difficult surgical technique; however, mid-term results are promising. Complications can sometimes occur, but are seldom serious. The main advantage of this promising bleb-less procedure is that physiological humor aqueous outflow is restored.
Understanding Municipal Officials' Involvement in Transportation Policies Supportive of Walking and Bicycling
Authors: Zwald Marissa L. , Eyler Amy A. , Goins Karin Valentine , Brownson Ross C. , Schmid Thomas L. , Lemon Stephenie C.
Published: October 2014

Context:

Local transportation policies can impact the built environment and physical activity. Municipal officials play a critical role in transportation policy and planning decisions, yet little is known about what influences their involvement.

Objective:

To describe municipal officials' involvement in transportation policies that were supportive of walking and bicycling and to examine individual- and job-related predictors of involvement in transportation policies among municipal officials.

Design:

A cross-sectional survey was administered online from June to July 2012 to municipal officials in 83 urban areas with a population of 50 000 or more residents across 8 states.

Participants:

A total of 461 municipal officials from public health, planning, transportation, public works, community and economic development, parks and recreation, city management, and municipal legislatures responded to the survey.

Main Outcome Measure:

Participation in the development, adoption, or implementation of a municipal transportation policy supportive of walking or bicycling.

Results:

Multivariate logistic regression analyses, conducted in September 2013, revealed that perceived importance of economic development and traffic congestion was positively associated with involvement in a municipal transportation policy (odds ratio [OR] = 1.32, 95% confidence interval [CI] = 1.02-1.70; OR = 1.59, 95% CI = 1.26-2.01, respectively). Higher perceived resident support of local government to address economic development was associated with an increased likelihood of participation in a transportation policy (OR = 1.70, 95% CI = 1.24-2.32). Respondents who perceived lack of collaboration as a barrier were less likely to be involved in a transportation policy (OR = 0.78, 95% CI = 0.63-0.97). Municipal officials who lived in the city or town in which they worked were significantly more likely to be involved in a transportation policy (OR = 1.83, 95% CI = 1.05-3.17).

Conclusions:

Involvement in a local transportation policy by a municipal official was associated with greater perceived importance of economic development and traffic congestion in job responsibilities, greater perceived resident support of local government to address economic development, and residence of the municipal official. Lack of collaboration represented a barrier to local transportation policy participation.
European starlings recognize the location of robotic conspecific attention
Authors: Butler Shannon R. , Fernández-Juricic Esteban
Published: October 2014

Looking where others are allocating attention can facilitate social interactions by providing information about objects or locations of interest. We asked whether European starlings follow the orientation behaviour of conspecifics owing to their highly gregarious behaviour. Starlings reoriented their attention to follow that of a robot around a barrier more often than when the robot's attention was directed elsewhere. This is the first empirical evidence of reorienting in response to conspecific attention in a songbird. Starlings may use this behaviour to obtain fine-tuned spatial information from conspecifics (e.g. direction of predator approach, spatial location of food patches), enhancing group cohesion.
Atomic force microscopy measurements reveal multiple bonds between
Helicobacter pylori
blood group antigen binding adhesin and Lewis b ligand
Authors: Parreira P. , Shi Q. , Magalhaes A. , Reis C. A. , Bugaytsova J. , Borén T. , Leckband D. , Martins M. C. L.
Published: October 2014

The strength of binding between the
Helicobacter pylori
blood group antigen-binding adhesin (BabA) and its cognate glycan receptor, the Lewis b blood group antigen (Le
b
), was measured by means of atomic force microscopy. High-resolution measurements of rupture forces between single receptor–ligand pairs were performed between the purified BabA and immobilized Le
b
structures on self-assembled monolayers. Dynamic force spectroscopy revealed two similar but statistically different bond populations. These findings suggest that the BabA may form different adhesive attachments to the gastric mucosa in ways that enhance the efficiency and stability of bacterial adhesion.
Variable tilt on lipid membranes
Authors: Rangamani P. , Steigmann D. J.
Published: October 2014

A continuum theory for lipid membranes is developed that accounts for mechanical interactions between lipid tilt and membrane shape. For planar membranes, a linear version of the theory is used to predict tilt variations similar to those observed in experiments and molecular dynamics simulations.
Integrable discretization of hodograph-type systems, hyperelliptic integrals and Whitham equations
Authors: Konopelchenko B. G. , Schief W. K.
Published: October 2014

Based on the well-established theory of discrete conjugate nets in discrete differential geometry, we propose and examine discrete analogues of important objects and notions in the theory of semi-Hamiltonian systems of hydrodynamic type. In particular, we present discrete counterparts of (generalized) hodograph equations, hyperelliptic integrals and associated cycles, characteristic speeds of Whitham-type and (implicitly) the corresponding Whitham equations. By construction, the intimate relationship with integrable system theory is maintained in the discrete setting.
Sex difference in travel is concentrated in adolescence and tracks reproductive interests
Authors: Miner Emily J. , Gurven Michael , Kaplan Hillard , Gaulin Steven J. C.
Published: October 2014

Sexual selection theory suggests that the sex with a higher potential reproductive rate will compete more strongly for access to mates. Stronger intra-sexual competition for mates may explain why males travel more extensively than females in many terrestrial vertebrates. A male-bias in lifetime distance travelled is a purported human universal, although this claim is based primarily on anecdotes. Following sexual maturity, motivation to travel outside the natal territory may vary over the life course for both sexes. Here, we test whether travel behaviour among Tsimane forager–horticulturalists is associated with shifting reproductive priorities across the lifespan. Using structured interviews, we find that sex differences in travel peak during adolescence when men and women are most intensively searching for mates. Among married adults, we find that greater offspring dependency load is associated with reduced travel among women, but not men. Married men are more likely to travel alone than women, but only to the nearest market town and not to other Tsimane villages. We conclude that men's and women's travel behaviour reflects differential gains from mate search and parenting across the life course.
Spatial congruence in language and species richness but not threat in the world's top linguistic hotspot
Authors: Turvey Samuel T. , Pettorelli Nathalie
Published: October 2014

Languages share key evolutionary properties with biological species, and global-level spatial congruence in richness and threat is documented between languages and several taxonomic groups. However, there is little understanding of the functional connection between diversification or extinction in languages and species, or the relationship between linguistic and species richness across different spatial scales. New Guinea is the world's most linguistically rich region and contains extremely high biological diversity. We demonstrate significant positive relationships between language and mammal richness in New Guinea across multiple spatial scales, revealing a likely functional relationship over scales at which infra-island diversification may occur. However, correlations are driven by spatial congruence between low levels of language and species richness. Regional biocultural richness may have showed closer congruence before New Guinea's linguistic landscape was altered by Holocene demographic events. In contrast to global studies, we demonstrate a significant negative correlation across New Guinea between areas with high levels of threatened languages and threatened mammals, indicating that landscape-scale threats differ between these groups. Spatial resource prioritization to conserve biodiversity may not benefit threatened languages, and conservation policy must adopt a multi-faceted approach to protect biocultural diversity as a whole.
Leaders benefit followers in the collective movement of a social sawfly
Authors: Hodgkin L. K. , Symonds M. R. E. , Elgar M. A.
Published: October 2014

The challenges of maintaining cohesion while making collective decisions in social or aggregating insects can result in the emergence of a leader or leaders. Larval aggregations of the steel-blue sawfly
Perga affinis
forage nocturnally, and some larvae lead the aggregation on foraging trips more often than expected by chance. We investigated the relationship between these leader and follower roles by comparing the weight and growth of individual larvae with different roles. Our observations reveal no significant difference between the growth of leaders and followers, suggesting that the role of leadership may not provide direct foraging benefits. However, by experimentally manipulating the social structure of larval aggregations, we found that individuals within aggregations that comprise a mixture of leaders and followers enjoy higher growth rates than those in aggregations comprising a single behavioural type. These data demonstrate, for the first time, individual benefits to maintaining a balance of leader and follower roles within larval aggregations, and highlight the importance of considering the perspectives of both leaders and followers when investigating the evolutionary significance of this behavioural variation within animal groups.
Sexually transmitted infection and the evolution of serial monogamy
Authors: McLeod David V. , Day Troy
Published: October 2014

The selective forces shaping mating systems have long been of interest to biologists. One particular selective pressure that has received comparatively little attention is sexually transmitted infections (STIs). While it has been hypothesized that STIs could drive the evolutionary emergence of monogamy, there is little theoretical support. Here we use an evolutionary invasion analysis to determine what aspects of pathogen virulence and transmission are necessary for serial monogamy to evolve in a promiscuous population. We derive a biologically intuitive invasion condition in terms of population-specific quantities. From this condition, we obtain two main results. First, when pathogen virulence causes mortality rather than sterility, monogamy is more likely to evolve. Second, we find that at intermediate pathogen transmission rates, monogamy is the most selectively advantageous, whereas at high- and low-transmission rates, monogamy is generally selected against. As a result, it is possible for a pathogen to be highly virulent, yet for promiscuity to persist.