bluuebunny/crossref_metadata_2025 huggingface dataset:
Mesoscale modeling of shear-thinning polymer solutions
Authors: Santos de Oliveira I. S. , Fitzgerald B. W. , den Otter W. K. , Briels W. J.
Published: March 2014

We simulate the linear and nonlinear rheology of two different viscoelastic polymer solutions, a polyisobutylene solution in pristane and an aqueous solution of hydroxypropylcellulose, using a highly coarse-grained approach known as Responsive Particle Dynamics (RaPiD) model. In RaPiD, each polymer has originally been depicted as a spherical particle with the effects of the eliminated degrees of freedom accounted for by an appropriate free energy and transient pairwise forces. Motivated by the inability of this spherical particle representation to entirely capture the nonlinear rheology of both fluids, we extended the RaPiD model by introducing a deformable particle capable of elongation. A Finite-Extensible Non-Linear Elastic potential provides a free energy penalty for particle elongation. Upon disentangling, this deformability allows more time for particles to re-entangle with neighbouring particles. We show this process to be integral towards recovering the experimental nonlinear rheology, obtaining excellent agreement. We show that the nonlinear rheology is crucially dependent upon the maximum elongation and less so on the elasticity of the particles. In addition, the description of the linear rheology has been retained in the process.
A two-dimensional nematic phase of magnetic nanorods
Authors: Slyusarenko Kostyantyn , Constantin Doru , Davidson Patrick
Published: March 2014

We report a hybrid mesophase consisting of magnetic nanorods confined between the non-ionic surfactant bilayers of a lamellar phase. The magnetic field-induced ordering of the nanorods was measured experimentally and modeled by a two-dimensional Onsager theory including the third virial coefficient. The nanorods are strongly confined in layers, with no orientational coupling from one layer to the next. At high volume concentration they exhibit spontaneous in-plane orientational ordering and form a stack of independent two-dimensional nematic systems. This isotropic-nematic transition is first-order.
Investigation of cellular microstructure and enhanced coercivity in sputtered Sm2(CoCuFeZr)17 film
Authors: Bhatt Ranu , Bhatt Pramod , Schütz G.
Published: March 2014

We have investigated the effect of annealing temperature on the microstructure and magnetic properties of Sm2(CoCuFeZr)17 films prepared using ion beam sputtering at room temperature. The as-deposited film shows randomly oriented polycrystalline grains and exhibits small coercivity (HC) of 0.04 T at room temperature. Post annealing of these films at 700 °C under Ar atmosphere shows significant changes in the microstructure transforming it to the development of cellular growth, concomitant with enhanced coercivity up to 1.3 T. The enhanced coercivity is explained using the domain wall pinning mechanism.
Dynamic range of atomically thin vibrating nanomechanical resonators
Authors: Wang Zenghui , Feng Philip X.-L.
Published: March 2014

Atomically thin two-dimensional (2D) crystals offer attractive properties for making resonant nanoelectromechanical systems (NEMS) operating at high frequencies. While the fundamental limits of linear operation in such systems are important, currently there is very little quantitative knowledge of the linear dynamic range (DR) and onset of nonlinearity in these devices, which are different than in conventional 1D NEMS such as nanotubes and nanowires. Here, we present theoretical analysis and quantitative models that can be directly used to predict the DR of vibrating 2D circular drumhead NEMS resonators. We show that DR has a strong dependence ∝10log(EY3/2ρ3D-1/2rtε5/2) on device parameters, in which strain ε plays a particularly important role in these 2D systems, dominating over dimensions (radius r, thickness t). This study formulizes the effects from device physical parameters upon DR and sheds light on device design rules toward achieving high DR in 2D NEMS vibrating at radio and microwave frequencies.
Modelling ferromagnetic resonance in magnetic multilayers: Exchange coupling and demagnetisation-driven effects
Authors: Baker A. A. , Davies C. S. , Figueroa A. I. , Shelford L. R. , van der Laan G. , Hesjedal T.
Published: March 2014

Ferromagnetic resonance in thin films and heterostructures is studied by micromagnetic simulation. Using a Fourier transform, we obtain the power spectrum of modes of precession and demonstrate that they agree with experimental results. Additional resonance modes associated with demagnetization effects are observed and studied as a function of the sample dimensions. Sufficiently confined geometries lead to a reorientation of the resonance mode, and a dramatic change in its frequency. Finally, the simulations are extended to exchange-coupled bilayers where energy is transferred between magnetic materials.
Magnetoelectric effect in Fe linear chains on Pt(001)
Authors: Manchanda P. , Skomski R. , Prabhakar A. , Kashyap A.
Published: March 2014

The effect of an electric field on the magnetic properties of Fe chains on Pt(001) is investigated by first-principle calculations. The calculated magnetic anisotropy of the chains yields a preferential magnetization perpendicular to the surface. We predict a linear change in the Fe magnetic moment as a function of the external electric field, which is due to spin-dependent screening of electrons. In the presence of electric field, we also obtain an enhancement in magnetic anisotropy as well as an orbital-moment anisotropy. The enhancement in magnetic anisotropy is due to a change in the d-electron occupancy of the surface atoms.
Radiative thermal rectification using superconducting materials
Authors: Nefzaoui Elyes , Joulain Karl , Drevillon Jérémie , Ezzahri Younès
Published: March 2014

Thermal rectification can be defined as an asymmetry in the heat flux when the temperature difference between two interacting thermal reservoirs is reversed. In this Letter, we present a far-field radiative thermal rectifier based on high-temperature superconducting materials with a rectification ratio up to 80%. This value is among the highest reported in literature. Two configurations are examined: a superconductor (Tl2Ba2CaCu2O8) exchanging heat with (1) a black body and (2) another superconductor, YBa2Cu3O7 in this case. The first configuration shows a higher maximal rectification ratio. Besides, we show that the two-superconductor rectifier exhibits different rectification regimes depending on the choice of the reference temperature, i.e., the temperature of the thermostat. Presented results might be useful for energy conversion devices, efficient cryogenic radiative insulators engineering, and thermal logical circuits’ development.
Revisiting the calibration of manganin gauges for lateral stress measurements in shock-loaded solids
Authors: Rosenberg Z. , Moshel G.
Published: March 2014

The calibration of manganin gauges for lateral stress measurements, in shock loaded specimens, is revisited through a simplified analysis, which is based on the dependence of the gauge's strength on shock amplitude. This dependence is derived from the measured resistive hysteresis of the gauge, as obtained in shock and release experiments. The resulting values for the gauge's strength, as a function of shock amplitude, are about half the values which were obtained previously by a different analysis. With the revised strength values, a new calibration curve is derived for the commercial grid-like gauges, as lateral stress transducers in planar impact experiments.
Determination of the magnetic penetration depth in a superconducting Pb film
Authors: Brisbois J. , Raes B. , Van de Vondel J. , Moshchalkov V. V. , Silhanek A. V.
Published: March 2014

By means of scanning Hall probe microscopy technique, we accurately map the magnetic field pattern produced by Meissner screening currents in a thin superconducting Pb stripe. The obtained field profile allows us to quantitatively estimate the Pearl length Λ without the need of pre-calibrating the Hall sensor. This fact contrasts with the information acquired through the spatial field dependence of an individual flux quantum where the scanning height and the magnetic penetration depth combine in a single inseparable parameter. The derived London penetration depth λL coincides with the values previously reported for bulk Pb once the kinetic suppression of the order parameter is properly taken into account.
Effects of intrinsic magnetostriction on tube-topology magnetoelectric sensors with high magnetic field sensitivity
Authors: Gillette Scott M. , Fitchorov Trifon , Obi Ogheneyunume , Jiang Liping , Hao Hongbo , Wu Shuangxia , Chen Yajie , Harris Vincent G.
Published: March 2014

Three quasi-one-dimensional magnetoelectric (ME) magnetic field sensors, each with a different magnetostrictive wire material, were investigated in terms of sensitivity and noise floor. Magnetostrictive Galfenol, iron-cobalt-vanadium, and iron-nickel wires were examined. Sensitivity profiles, hysteresis effects, and noise floor measurements for both optimally biased and zero-biased conditions are presented. The FeNi wire (FN) exhibits high sensitivity (5.36 mV/Oe) at bias fields below 22 Oe and an optimal bias of 10 Oe, whereas FeGa wire (FG) exhibits higher sensitivity (6.89 mW/Oe) at bias fields >22 Oe. The sensor of FeCoV wire (FC) presents relatively low sensitivity (2.12 mV/Oe), due to low magnetostrictive coefficient. Each ME tube-topology sensor demonstrates relatively high sensitivity at zero bias field, which results from a magnetic shape anisotropy and internal strain of the thin magnetostrictive wire.
Tunable and angle-insensitive plasmon resonances in graphene ribbon arrays with multispectral diffraction response
Authors: Li Kangwen , Ma Xunpeng , Zhang Zuyin , xu Yun , Song Guofeng
Published: March 2014

Plasmon resonances in graphene ribbon arrays are investigated numerically by means of the Finite Element Method. Numerical analysis shows that a series of multipolar resonances take place when graphene ribbon arrays are illuminated by a TM polarized electromagnetic wave. Moreover, these resonances are angle-independent, and can be tuned greatly by the width and the doping level of the graphene ribbons. Specifically, we demonstrate that for graphene arrays with several sets of graphene ribbons, which have different widths or doping levels, each of these multipolar resonances will be split into several ones. In addition, as plasmon resonances can confine electromagnetic field at the ribbon edges, graphene ribbons with different widths or doping levels offer intriguing application for electrically tunable spectral imaging.
The adsorption properties of CO molecules on single-layer graphene nanoribbons
Authors: Yi Chenglong , Wang Weidong , Shen Cuili
Published: March 2014

The adsorption properties of CO molecules on graphene nanoribbons (GRNs) are studied through the molecular dynamics (MD) method. The AIREBO and LJ potentials are used to describe the C-C bonds in GNR and the interactions between the carbon atoms in GNR and CO molecules, respectively. The influences of the environmental pressure and charge density on the adsorption properties of CO molecules on GRNs are taken into account in this study. The effects of charges carried by GNRs on the adsorption properties are investigated in two aspects: atom distribution and energy evolution. Its observation from the results shows that the Coulomb force plays a more important role in the adsorption phenomenon than the van der Waals force, and the higher the charge density is, the larger the amount of the adsorbed CO molecules becomes. Low charge densities (<3.291 C/m2) do little for the system, that is to say, the GNRs present similar properties to the ones with no charges. However, relatively high charge densities (>4.937 C/m2) have an obvious effect on the whole system. The results also indicate that the environmental pressure has great influence on the adsorption properties of COs on GRN, and the higher the pressure is, the greater the adsorption energy becomes.
The influence of nonideal factors on the capacitance permittivity in a liquid-suspended rotor micro-gyroscope
Authors: Ren Ming-Yuan , Zhang Hai-Feng , Liu Xiao-Wei , Mao Zhi-Gang
Published: March 2014

The nonideal factors of a liquid-suspended rotor micro-gyroscope include the gas-liquid two-phase flow voids, medium temperature and its dielectric relaxation, in which the role of the nonideal factors on the capacitor dielectric constant is altered, thereby affecting the capacitance detection precision of the micro-gyroscope. By comparing four different liquid media, the experimental results reveal the nonideal character of the capacitor dielectric constant. The 7# white oil is suitable for use as the liquid-suspended gyro cavity liquid medium.
CuAAC and RuAAC with Alkyne-functionalised Dihydroazulene Photoswitches and Determination of Hammett σ-Constants for Triazoles
Authors: Lissau Henriette , Broman Søren Lindbæk , Jevric Martyn , Madsen Anders Ø. , Nielsen Mogens Brøndsted
Published: March 2014

Dihydroazulene (DHA)–vinylheptafulvene (VHF) photoswitches have attracted attention as potentially useful components in molecular electronics. The π-conjugated dihydroazulene system is a rigid structure and can be strategically functionalised to place handles for further elaboration. Here we show that alkyne-functionalised dihydroazulenes can be subjected to copper and ruthenium catalysed azide–alkyne cycloadditions (CuAAC and RuAAC) with tolylazide, furnishing 1,4- and 1,5-disubstituted triazoles. The rates of ring-closure of the corresponding vinylheptafulvenes were compared with those of reference systems, which allowed determination of Hammett substituent constants (meta and para) for N-tolyl-substituted 1,2,3-triazoles.
Orientation of tawny frogmouth (Podargus strigoides) nests and their position on branches optimises thermoregulation and cryptic concealment
Authors: Rae Stuart , Rae Duncan
Published: March 2014

Tawny frogmouth (Podargus strigoides) nests were surveyed in grassy woodland, dry sclerophyll forest and suburbia in the Australian Capital Territory. In total, 253 tawny frogmouth nests were recorded in 145 nest sites. Nests were oriented to the north-east, which would expose them to morning sunshine and partially shelter them from the prevailing wind. Most nests were placed in rough or flaky-barked tree species, on open mid-branch sites with no foliage, where the birds’ plumage and posture resemble the colour and form of the branches. Although smooth-barked gum trees were the most abundant types in the dry sclerophyll forest they were seldom used. Nest sites in all habitats were similar; the mean nest height was 9.2 m, and most nests were set on forks in the lowest branches. By placing their nests in these positions tawny frogmouths likely maximise their potential thermoregulation, protection from wind, concealment from predators, and detection of approaching predators.
Safety, pharmacokinetics, and preliminary assessment of efficacy of mecasermin (recombinant human IGF-1) for the treatment of Rett syndrome
Authors: Khwaja Omar S. , Ho Eugenia , Barnes Katherine V. , O’Leary Heather M. , Pereira Luis M. , Finkelstein Yaron , Nelson Charles A. , Vogel-Farley Vanessa , DeGregorio Geneva , Holm Ingrid A. , Khatwa Umakanth , Kapur Kush , Alexander Mark E. , Finnegan Deirdre M. , Cantwell Nicole G. , Walco Alexandra C. , Rappaport Leonard , Gregas Matt , Fichorova Raina N. , Shannon Michael W. , Sur Mriganka , Kaufmann Walter E.
Published: March 2014

Significance

This paper provides unique insights into mechanism-based therapeutics for Rett syndrome (RTT), a devastating neurodevelopmental disorder. This clinical trial was based on pioneer preclinical work from the laboratory of M.S. Outcome measures include clinical instruments, standardized behavioral measures, and biomarkers, the latter being not only objective but also applicable to experimental studies. We believe this work will a have major impact on the understanding and treatment of RTT, as well as other neurodevelopmental disorders.
Computation of the topological type of a real Riemann surface
Authors: Kalla C. , Klein C.
Published: March 2014

We present an algorithm for the computation of the topological type of a real compact Riemann surface associated to an algebraic curve, i.e., its genus and the properties of the set of fixed points of the anti-holomorphic involution

τ
\tau

, namely, the number of its connected components, and whether this set divides the surface into one or two connected components. This is achieved by transforming an arbitrary canonical homology basis to a homology basis where the

A

\mathcal {A}

-cycles are invariant under the anti-holomorphic involution 

τ
\tau

.
The fission yeast spore is coated by a proteinaceous surface layer comprising mainly Isp3
Authors: Fukunishi Kana , Miyakubi Kana , Hatanaka Mitsuko , Otsuru Natsumi , Hirata Aiko , Shimoda Chikashi , Nakamura Taro
Published: March 2014

The spore is a dormant cell that is resistant to various environmental stresses. As compared with the vegetative cell wall, the spore wall has a more extensive structure that confers resistance on spores. In the fission yeast Schizosaccharomyces pombe, the polysaccharides glucan and chitosan are major components of the spore wall; however, the structure of the spore surface remains unknown. We identify the spore coat protein Isp3/Meu4. The isp3 disruptant is viable and executes meiotic nuclear divisions as efficiently as the wild type, but isp3∆ spores show decreased tolerance to heat, digestive enzymes, and ethanol. Electron microscopy shows that an electron-dense layer is formed at the outermost region of the wild-type spore wall. This layer is not observed in isp3∆ spores. Furthermore, Isp3 is abundantly detected in this layer by immunoelectron microscopy. Thus Isp3 constitutes the spore coat, thereby conferring resistance to various environmental stresses.
Variation in Firmness of Whole Beans, Embryos, and Testas of Cooked Soybean (Glycine max) Cultivars
Authors: Yasui Takeshi , Sasaki Tomoko , Kohyama Kaoru , Hajika Makita
Published: March 2014

The firmness of whole beans and of separated embryos and testas from 20 soybean cultivars grown in the same field conditions was estimated after 40 min cooking with AACC International Approved Method 56‐36.01. There were considerable variations in the firmness of whole beans, embryos, and testas among cultivars. Testas were much firmer than embryos because of their leathery texture and resistance at slots in the shear cell during compression. For soft cultivars, the firmness after 10 min cooking was also measured, and an apparent first‐order reaction kinetics model was applied to estimate the initial firmness at 0 min cooking and the softening rate constant from firmness data after 10 and 40 min cooking. The estimated initial firmness at 0 min cooking and softening rate constant of embryos and testas varied widely among seven cultivars, and these two parameters were considered to be controlled by different genetic mechanisms, because no correlation was found between the parameters. The softening rate constants of testas were much smaller than those of embryos, and the relative firmness of testas to embryos increased during cooking. The firmness of whole beans and embryos after 10 min cooking would be a useful characteristic for approximating their firmness after 40 min cooking.
HopZ4 from Pseudomonas syringae, a Member of the HopZ Type III Effector Family from the YopJ Superfamily, Inhibits the Proteasome in Plants
Authors: Üstün Suayib , König Patrick , Guttman David S. , Börnke Frederik
Published: March 2014

The YopJ family of type III effector proteins (T3E) is one of the largest and most widely distributed families of effector proteins, whose members are highly diversified in virulence functions. In the present study, HopZ4, a member of the YopJ family of T3E from the cucumber pathogen Pseudomonas syringae pv. lachrymans is described. HopZ4 shares high sequence similarity with the Xanthomonas T3E XopJ, and a functional analysis suggests a conserved virulence function between these two T3E. As has previously been shown for XopJ, HopZ4 interacts with the proteasomal subunit RPT6 in yeast and in planta to inhibit proteasome activity during infection. The inhibitory effect on the proteasome is dependent on localization of HopZ4 to the plasma membrane as well as on an intact catalytic triad of the effector protein. Furthermore, HopZ4 is able to complement loss of XopJ in Xanthomonas spp., as it prevents precocious host cell death during a compatible Xanthomonas-pepper interaction. The data presented here suggest that different bacterial species employ inhibition of the proteasome as a virulence strategy by making use of conserved T3E from the YopJ family of bacterial effector proteins.
Transcriptomic Analysis Reveals That Reactive Oxygen Species and Genes Encoding Lipid Transfer Protein Are Associated with Tobacco Hairy Root Growth and Branch Development
Authors: Wang Jung-Hao , Lin Hsiao-Han , Liu Chi-Te , Lin Ta-Chung , Liu Li-yu Daisy , Lee Kung-Ta
Published: March 2014

The hairy root, a specialized plant tissue that emerges from a cell transformed with transfer DNA (T-DNA) from Agrobacterium rhizogenes, can be used to study root biology and utilized in biotechnological applications. The rol genes are known to participate in the generation of hairy roots; however, the means by which the rol genes contribute to the initiation and the maintenance of hairy roots remains largely unknown. We demonstrated that tobacco hairy roots lacking either rolB or rolC exhibited fewer branch roots and lost their growth ability in long-term subculture. Additionally, a microarray analysis revealed that the expression of several genes encoding lipid transfer proteins (LTP) and reactive oxygen species (ROS)-related genes was significantly suppressed in rolB- or rolC-deficient hairy roots. We found that hairy root clones that exhibited greater branching expressed higher levels of RolB or RolC and the genes encoding LTP identified from the microarray. When hairy roots were compared with intact roots, the expression levels of LTP-encoding genes were dramatically different. In addition, ROS were present at lower levels in rolB- and rolC-deficient hairy roots. We therefore suggest that upregulating LTP and increasing the level of ROS is important for hairy root growth.
A Conceptual Model to Describe the Decline of European Blackberry (Rubus anglocandicans), A Weed of National Significance in Australia
Authors: Aghighi S. , Fontanini L. , Yeoh P. B. , Hardy G. E. St. J. , Burgess T. I. , Scott J. K.
Published: March 2014

Human activities have had an adverse impact on ecosystems on a global scale and have caused an unprecedented redispersal of organisms, with both plants and pathogens moving from their regions of origin to other parts of the world. Invasive plants are a potential threat to ecosystems globally, and their management costs tens of billions of dollars per annum. Rubus anglocandicans (European blackberry) is a serious invasive species in Australia. Herbicide and cultural control methods are generally inefficient or require multiple applications. Therefore, a biological control program using stem and leaf rust strains is the main option in Australia. However, biological control using rusts has been patchy, as host factors, climate, and weather can alter the impact of the rust at different locations. In 2007, Yeoh and Fontanini noticed that blackberry plants on the banks of the Donnelly and Warren rivers in the southwest of Western Australia were dying in areas that were being regularly monitored for the impact of rust as a biological control agent. The symptoms on blackberry became known as the disease “blackberry decline”. Continuous and intensive investigations are required to discover the different biotic and abiotic components associated with specific declines in plant populations. The only agent so far introduced to Australia for the biological control of blackberry is the rust Phragmidium violaceum.
The Epidemic Spread of Seiridium cardinale on Leyland Cypress Severely Limits Its Use in the Mediterranean
Authors: Danti R. , Barberini S. , Pecchioli A. , Di Lonardo V. , Della Rocca G.
Published: March 2014

Leyland cypress (× Hesperotropsis leylandii) is a fast-growing conifer used in most temperate regions as an ornamental tree for hedges and screens, and is one of the most commercially important trees in Europe. In recent years, severe diebacks and mortality due to cypress canker have been observed on Leyland cypress plantations in Southern Europe. This study was conducted to evaluate (i) the spread and impact of cypress canker caused by Seiridium cardinale in plantations of a sample area of 1,250 km2 in central Italy, (ii) the response of the most commonly grown Leyland cypress varieties to artificial inoculation with to S. cardinal, and (iii) the pathogenicity of S. cardinale isolates obtained from Leyland cypress. Of the 1,411 surveyed trees, 11.4% had been killed by cypress canker and 43.9% of the living trees were affected by the disease. The number of diseased or dead trees and the percentage of cankered trunks was significantly correlated with the mean trunk diameter of the plantations. Six months after inoculation, the size of developed cankers was significantly different among the inoculated Leyland cypress cultivars but all of them showed markedly larger cankers than the C. sempervirens canker-resistant control clone. All of the tested S. cardinale isolates obtained from Leyland cypress also caused cankers on Cupressus sempervirens when inoculated as conidial suspensions or mycelia. Leyland cypress is highly prone to contract cypress canker in the Mediterranean due to its high susceptibility to S. cardinale infections, low genetic variability among the grown cultivars, and cracks which form on fast-growing trunks, favoring entry of the fungus into the inner bark and the occurrence of infections.
Control of Curly Top in Sugar Beet with Seed and Foliar Insecticides
Authors: Strausbaugh Carl A. , Wenninger Erik J. , Eujayl Imad A.
Published: March 2014

Curly top in sugar beet is a serious problem that is caused by Beet curly top virus and other closely related species and transmitted by the beet leafhopper. In order to find a means of reducing curly top in sugar beet, 15 combinations of insecticide seed (Poncho, Poncho Beta, and Poncho Votivo) and foliar (Asana, Cyazypyr, Lorsban, Mustang, Scorpion, and Sivanto) treatments were evaluated versus an untreated check during the 2012 and 2013 growing seasons. An epiphytotic was created by releasing viruliferous beet leafhoppers 58 to 59 days after planting. The foliar sprays were applied 6 to 7 days before and again 6 to 8 days after leafhopper release. Seed treatments (active ingredient: clothianidin) were able to reduce symptoms by 26 to 42% and increase recoverable sucrose by 16 to 21%. The pyrethroids Asana and Mustang also performed well by reducing symptoms 22 to 56% and increasing yields 13 to 20%. The neonicotinoid seed treatments should be an effective way of supplementing host resistance for early-season (at least 59 days after planting) curly top control in sugar beet. The pyrethroid foliar applications could be used to extend curly top control during the midseason period and provide resistance management.
New Races of Puccinia striiformis Found in Europe Reveal Race Specificity of Long-Term Effective Adult Plant Resistance in Wheat
Authors: Sørensen Chris K. , Hovmøller Mogens S. , Leconte Marc , Dedryver Françoise , de Vallavieille-Pope Claude
Published: March 2014

Resistance to Puccinia striiformis was examined in nine wheat recombinant inbred lines (RILs) from a cross between ‘Camp Rémy’ (resistant parent) and ‘Récital’ (susceptible parent) using an isolate of a strain common to the northwestern European population before 2011 (old) and two additional isolates, one representing an aggressive and high-temperature-adapted strain (PstS2) and another representing a virulence phenotype new to Europe since 2011 (new). The RILs carried different combinations of quantitative trait loci (QTL) for resistance to P. striiformis. Under greenhouse conditions, the three isolates gave highly contrasting results for infection type, latent period, lesion length, and diseased leaf area. The PstS2 isolate revealed Yr genes and QTL which conferred complete resistance in adult plants. Six QTL had additive effects against the old isolate whereas the effects of these QTL were significantly lower for the new isolate. Furthermore, the new isolate revealed previously undetected resistance in the susceptible parent. Disease severity under field conditions agreed with greenhouse results, except for Camp Rémy being fully resistant to the new isolate and for two RILs being susceptible in the field. These results stress the need of maintaining high genetic diversity for disease resistance in wheat and of using pathogen isolates of diverse origin in studies of host resistance genetics.
Responses to iron limitation are impacted by light quality and regulated by RcaE in the chromatically acclimating cyanobacterium Fremyella diplosiphon
Authors: Pattanaik Bagmi , Busch Andrea W. U. , Hu Pingsha , Chen Jin , Montgomery Beronda L.
Published: March 2014

Photosynthetic organisms adapt to environmental fluctuations of light and nutrient availability. Iron is critical for photosynthetic organismal growth, as many cellular processes depend upon iron cofactors. Whereas low iron levels can have deleterious effects, excess iron can lead to damage, as iron is a reactive metal that can result in the production of damaging radicals. Therefore, organisms regulate cellular iron levels to maintain optimal iron homeostasis. In particular, iron is an essential factor for the function of photosystems associated with photosynthetic light-harvesting complexes. Photosynthetic organisms, including cyanobacteria, generally respond to iron deficiency by reduced growth, degradation of non-essential proteins and in some cases alterations of cellular morphology. In response to fluctuations in ambient light quality, the cyanobacterium Fremyella diplosiphon undergoes complementary chromatic adaptation (CCA). During CCA, phycobiliprotein composition of light-harvesting antennae is altered in response to green light (GL) and red light (RL) for efficient utilization of light energy for photosynthesis. We observed light-regulated responses to iron limitation in F. diplosiphon. RL-grown cells exhibited significant reductions in growth and pigment levels, and alterations in iron-associated proteins, which impact the accumulation of reactive oxygen species under iron-limiting conditions, whereas GL-grown cells exhibited partial resistance to iron limitation. We investigated the roles of known CCA regulators RcaE, RcaF and RcaC in this light-dependent iron-acclimation response. Through comparative analyses of wild-type and CCA mutant strains, we determined that photoreceptor RcaE has a central role in light-induced oxidative stress associated with iron limitation, and impacts light-regulated iron-acclimation responses, physiologically and morphologically.
Microfocusing options for the inelastic X-ray scattering beamline at sector 3 of the Advanced Photon Source
Authors: Alsmadi A. M. , Alatas A. , Zhao J. Y. , Hu M. Y. , Yan L. , Alp E. E.
Published: March 2014

Synchrotron radiation from third-generation high-brilliance storage rings is an ideal source for X-ray microbeams. The aim of this paper is to describe a microfocusing scheme that combines both a toroidal mirror and Kirkpatrick–Baez (KB) mirrors for upgrading the existing optical system for inelastic X-ray scattering experiments at sector 3 of the Advanced Photon Source.SHADOWray-tracing simulations without considering slope errors of both the toroidal mirror and KB mirrors show that this combination can provide a beam size of 4.5 µm (H) × 0.6 µm (V) (FWHM) at the end of the existing D-station (66 m from the source) with use of full beam transmission of up to 59%, and a beam size of 3.7 µm (H) × 0.46 µm (V) (FWHM) at the front-end of the proposed E-station (68 m from the source) with a transmission of up to 52%. A beam size of about 5 µm (H) × 1 µm (V) can be obtained, which is close to the ideal case, by using high-quality mirrors (with slope errors of less than 0.5 µrad r.m.s.). Considering the slope errors of the existing toroidal and KB mirrors (5 and 2.9 µrad r.m.s., respectively), the beam size grows to about 13.5 µm (H) × 6.3 µm (V) at the end of the D-station and to 12.0 µm (H) × 6.0 µm (V) at the front-end of the proposed E-station. The simulations presented here are compared with the experimental measurements that are significantly larger than the theoretical values even when slope error is included in the simulations. This is because of the experimental set-up that could not yet be optimized.
About systematic errors in charge-density studies
Authors: Henn Julian , Meindl Kathrin
Published: March 2014

The formerly introduced theoreticalRvalues [Henn & Schönleber (2013).Acta Cryst.A69, 549–558] are used to develop a relative indicator of systematic errors in model refinements,Rmeta, and applied to published charge-density data. The counter ofRmetagives an absolute measure of systematic errors in percentage points. The residuals (Io−Ic)/σ(Io) of published data are examined. It is found that most published models correspond to residual distributions that are not consistent with the assumption of a Gaussian distribution. The consistency with a Gaussian distribution, however, is important, as the model parameter estimates and their standard uncertainties from a least-squares procedure are valid only under this assumption. The effect of correlations introduced by the structure model is briefly discussed with the help of artificial data and discarded as a source of serious correlations in the examined example. Intensity and significance cutoffs applied in the refinement procedure are found to be mechanisms preventing residual distributions from becoming Gaussian. Model refinements against artificial data yield zero or close-to-zero values forRmetawhen the data are not truncated and small negative values in the case of application of a moderate cutoffIo> 0. It is well known from the literature that the application of cutoff values leads to model bias [Hirshfeld & Rabinovich (1973).Acta Cryst.A29, 510–513].
Seitz symbols for crystallographic symmetry operations
Authors: Glazer A. Michael , Aroyo Mois I. , Authier André
Published: March 2014

The aim of this report is to describe the Seitz notation for symmetry operations adopted by the Commission on Crystallographic Nomenclature as the standard convention for Seitz symbolism of the International Union of Crystallography. The established notation follows the existing crystallographic conventions in the descriptions of symmetry operations.
The “School Foodshed”: schools and fast-food outlets in a London borough
Authors: Caraher M. , Lloyd S. , Madelin T.
Published: March 2014

Purpose

– The purpose of this paper is to explore the location of fast-food outlets around secondary schools and the influence of fast-food availability on the food choices of school children in an inner-London borough.

Design/methodology/approach

– A number of methods including: mapping of outlets relative to schools; sampling food; gathering data on secondary school food policies; observing food behaviour in fast food outlets and focus groups with young people. Findings were fed back to a committee consisting of representatives from nutrition, public health, planning services and local community groups.

Findings

– There are concentrations of fast-food outlets near schools and students reported use of these, including “stories” of skipping lunch in order to save money and eat after school at these outlets. Food from fast-food outlets was high in fat, saturated fat and salt, but these are not the only source of high such foods, with many of the students reporting buying from shops near the school or on the way to or from school. At lunchtime food outlets were less likely to be used by school students in areas near schools that have a “closed gate” policy.

Research limitations/implications

– The “snapshot” nature of the research limited what can be said about the food behaviours of the children outside school hours.

Practical implications

– The local policy context requires action to improve both the food offered in schools and the immediate environment around the school in order to tackle fast-food and other competitive foods on offer outside the school.

Originality/value

– This is one of the first studies in the UK to systematically map fast food outlets around schools and explore what might be done. This research shows how it is possible to link the findings of local research and develop local responses from both public health and local authority planning perspectives. The research moves away from a mere documenting of problems to devising integrated public health solutions. The findings show how public health and planning services can work together to the mutual benefit of each other.
Analysis of UK walnut market import purchase behaviour
Authors: McNeil D.L. , Felgate M.K.
Published: March 2014

Purpose

– This paper aims to use readily available data to validate several predictions on UK walnut import and consumer use behaviours. It then seeks to hypothesise how this information can be used to determine whether and how additional value can be created in the chain.

Design/methodology/approach

– The chain used was that from sourcing to retail sale of walnuts in the UK. The data used were: UK import price/quantity/origin and total consumption data, global comparisons for import price/quantity/origin and total consumption data.

Findings

– This paper validates predictions for walnut quality, market size and pricing from a simple model for the UK walnut market. The UK walnut market is small (0.26 g/capita/day) but expanding per capita (8 per cent pa). Import prices are low (15-25 per cent below several other major EU importers) but rising in real terms (7 per cent pa). The UK generally sources walnuts opportunistically from low cost low “international standard” quality suppliers. These findings are consistent with model predictions of market behaviour and previous findings on walnut quality.

Practical implications

– There may be an opportunity to improve quality specifications for the UK walnut market &/or to expand the UK market into higher quality uses. Both options require educating the UK consumer market in the additional consumer value created.

Originality/value

– The study indicates the extent of price seeking purchasing behaviour within global markets for an agricultural product (walnuts). It shows this is not a globally consistent market response and thus offers opportunities for all participants in the UK walnut retail value chain to provide enhanced consumer value.
Why regular buyers of organic food still buy many conventional products
Authors: Buder Fabian , Feldmann Corinna , Hamm Ulrich
Published: March 2014

Purpose

– The sales volume of organic food products in Germany has been increasing consistently over recent years, yet only a small number of households is responsible for the majority of organic purchases. Even these so-called “regular” organic food buyers spend, on average, less than half of their budget on organic products. The present study aims to analyse the reasons why these consumers do not purchase particular products in organic quality, in order to uncover product gaps and purchase barriers.

Design/methodology/approach

– The investigation is based on computer-aided, personal interviews among regular organic food buyers, which were conducted in retail and organic food stores across Germany. Altogether, 817 interviews were carried out. To minimize regional variation in the data-set, stores were selected from north, south, west and east Germany in equal proportions.

Findings

– The most important reasons for not purchasing organic products among regular organic food consumers were price, insufficient availability, and the quality of the product. Since product-specific analysis was carried out in this study, the results indicate that the relevance of reasons varies from product to product and according to shop types.

Originality/value

– To the authors' knowledge, no research to date has dealt with an analysis of product-specific purchase barriers in the context of regular organic food buyers. Furthermore, in contrast with other studies, a preceding analysis of panel data identifying product groups with the lowest organic market shares builds the basis for a well-grounded survey. The explorative character of the study results in unique findings on consumer purchase behaviour related to specific products in a variety of predefined product categories.
Antecedents of food-related consumer decision-making styles
Authors: Anić Ivan-Damir , Piri Rajh Suncana , Rajh Edo
Published: March 2014

Purpose

– This study aims to examine the impacts of demographic variables (gender, age, income, education) and food product involvement (FPI) on food-related consumer decision-making styles (CDMS).

Design/methodology/approach

– Original Sproles and Kendall's CSI instrument (1986) was applied in the food-product context. Data were collected using consumer phone survey. Eight separate regression analyses were conducted to test hypotheses. In each model independent variables were socio-demographic variables and FPI, while dependent variables were eight food-related CDMS.

Findings

– Regression analyses indicate that each of food-related CDMS are affected by different antecedent variables. Perfectionism, high-quality consciousness was affected by gender, age, income and FPI; Brand consciousness by age, income and FPI; Novelty consciousness by FPI; Recreational, hedonistic shopping consciousness by gender, age and FPI; Price consciousness by age, education and income; Impulsiveness by age, education and income; Confusion by overchoice by education and FPI, and Brand loyalty by education, income and FPI.

Originality/value

– The study applies modified Sproles and Kendall's CSI instrument (1986) in the food product context. The present study also provides a more definitive conclusion about the relationships between demographics, FPI and food-related CDMS. The analysis determined how demographics and FPI affect food-related CDMS.
Informal e-learning: the case of small business owners
Authors: Smith Tara , Barrett Rowena
Published: March 2014

Purpose

– The purpose of this paper is to investigate the use of an informal online discussion forum (ODF) to encourage voluntary participation and promote double-loop learning by small business owners (SBOs).

Design/methodology/approach

– A qualitative methodology was used where data gathered from three sources, the ODF posts, in-depth interviews with participants and a focus group with non-participants. These were analysed to evaluate learning of SBOs in an ODF.

Findings

– This research provides evidence that an ODF for SBOs supports double-loop learning; however, participation could not be assumed simply by the online availability of the discussion resource.

Research limitations/implications

– Few SBOs participated in the ODF which is consistent with research finding SBOs are a difficult group to engage in learning. Four forms of data were analysed to strengthen results.

Practical implications

– Caution should be exercised when considering investment in e-learning for SBOs.

Originality/value

– Evidence showing e-learning through an informal voluntary ODF can promote deep learning for SBOs.
Using e-learning to support international students’ dissertation preparation
Authors: Sloan Diane , Porter Elizabeth , Robins Karen , McCourt Karen
Published: March 2014

Purpose

– A research paper on the design and implementation of an e-learning resource responding to the globalisation of education. The purpose of this paper is to focus on the challenges presented in learning and teaching on how to support international postgraduate (PG) students undertaking the specific task of a dissertation.

Design/methodology/approach

– Using findings from 250 PG students, 40 supervisors and two module tutors the research identified the content and language issues faced by students and recognised the need to design an enabler supporting the latter as independent learners and the academic staff delivering support.

Findings

– The e-learning tool provides an independent learning tool which addresses student concerns relating to the process and content of structuring a dissertation and the function of language. Initial responses have been positive from both staff and students in respect to providing a source of student support and feedback.

Originality/value

– The research shows how the Dissertation Game Model (DGM), evolved into an e-learning resource supporting student understanding of the content, structure, planning and writing of a dissertation. The e-learning tool focuses on helping international students understand what the generic contents of each chapter of a dissertation should contain and supports them in engaging in research as a transferable skill.
Competitive advantage in the new social care marketplace: a new theoretical perspective
Authors: Dearnaley Patricia
Published: March 2014

Purpose

– Changes in the UK social care sector over the past 20 years have effected a fundamental shift in commissioning and delivery relationships. This “quasi-market” challenges existing theory and models around competitive advantage. This study, as outlined in two earlier articles, addressed weaknesses in the defining framework for analysis and business planning in this new environment; the purpose of this concluding paper is to propose a new perspective for those interested in entering this market.

Design/methodology/approach

– The original research comprised a constructive research approach through a single holistic case study, using qualitative research methods including document analysis, interviews, secondary data, observations and facilitated meetings.

Findings

– This final paper offers a structured framework of analysis and response: the External Drivers Model.

Research limitations/implications

– The model was developed for a scenario impacting upon a social housing agency, with ambitions to enter this market as a new provider; it may require further research to establish its generalisability to other organisations and other sectors.

Originality/value

– This series of three papers adds to existing knowledge by critiquing current business models, and positing a potential development to existing contingency theory: the External Drivers Model. The study has resulted in a number of outputs including an outline of tools to assist in using the model.
Shared housing and long-term mental illness
Authors: Abrahamson David
Published: March 2014

Purpose

– The purpose of this paper is to give an account by a rehabilitation psychiatrist of many years of involvement in shared housing for former long-stay hospital residents and other long-term mental health service users.

Design/methodology/approach

– The paper offers a personal view based on developments in one locality of East London, blending case study narrative with cited earlier published papers that confirm and/or give greater detail on specific aspects of the experience gained.

Findings

– Long-term mental health service users, given the opportunity via shared housing to develop more lasting and natural relationships, proved to have social and interactive capacity that was obscured by both the conditions of hospital wards and by isolating accommodation “in the community”. The experience provides lessons for a better understanding of patients’ problems.

Practical implications

– Shared housing is often seen as simply a poor substitute for independent living; but the experience recounted here suggests that shared living may have particular value for some client groups.

Originality/value

– The housing developments and the associated research remain unusual and of potential value for planners of long-term services.