bluuebunny/crossref_metadata_2025 huggingface dataset:
On stabilization of scattering resonances in recombination reaction that forms ozone
Authors: Ivanov Mikhail V. , Babikov Dmitri
Published: April 2016

Calculations of energy transfer in the recombination reaction that forms ozone are carried out within the framework of the mixed quantum/classical theory and using the dimensionally reduced 2D-model of ozone molecule, with bending motion neglected. Recombination rate coefficients are obtained at room temperature for symmetric and asymmetric isotopomers of singly and doubly substituted isotopologues. The processes of resonance formation, spontaneous decay, collisional dissociation, and stabilization by bath gas (Ar) are all characterized and taken into account within the steady-state approximation for kinetics. The focus is on stabilization step, where the mysterious isotopic η-effect was thought to originate from. Our results indicate no difference in cross sections for stabilization of scattering resonances in symmetric and asymmetric isotopomers. As practical results, the general and simple analytic models for stabilization and dissociation cross sections are presented, which can be applied to resonances in any ozone molecule, symmetric or asymmetric, singly or doubly substituted. Present calculations show some isotope effect that looks similar to the experimentally observed η-effect, and the origin of this phenomenon is in the rates of formation/decay of scattering resonances, determined by their widths, that are somewhat larger in asymmetric isotopomers than in their symmetric analogues. However, the approximate two-dimensional model used here is insufficient for consistent and reliable description of all features of the isotopic effect in ozone. Calculations using an accurate 3D model are still needed.
The generation of magnetic fields by the Biermann battery and the interplay with the Weibel instability
Authors: Schoeffler K. M. , Loureiro N. F. , Fonseca R. A. , Silva L. O.
Published: April 2016

An investigation of magnetic fields generated in an expanding bubble of plasma with misaligned temperature and density gradients (driving the Biermann battery mechanism) is performed. With gradient scales L, large-scale magnetic fields are generated by the Biermann battery mechanism with plasma β ∼ 1, as long as L is comparable to the ion inertial length di. For larger system sizes, L/de > 100 (where de is the electron inertial length), the Weibel instability generates magnetic fields of similar magnitude but with wavenumber kde ≈ 0.2. In both cases, the growth and saturation of these fields have a weak dependence on mass ratio mi/me, indicating electron mediated physics. A scan in system size is performed at mi/me = 2000, showing agreement with previous results with mi/me = 25. In addition, the instability found at large system sizes is quantitatively demonstrated to be the Weibel instability. Furthermore, magnetic and electric energy spectra at scales below the electron Larmor radius are found to exhibit power law behavior with spectral indices −16/3 and −4/3, respectively.
Radiation pressure acceleration: The factors limiting maximum attainable ion energy
Authors: Bulanov S. S. , Esarey E. , Schroeder C. B. , Bulanov S. V. , Esirkepov T. Zh. , Kando M. , Pegoraro F. , Leemans W. P.
Published: April 2016

Radiation pressure acceleration (RPA) is a highly efficient mechanism of laser-driven ion acceleration, with near complete transfer of the laser energy to the ions in the relativistic regime. However, there is a fundamental limit on the maximum attainable ion energy, which is determined by the group velocity of the laser. The tightly focused laser pulses have group velocities smaller than the vacuum light speed, and, since they offer the high intensity needed for the RPA regime, it is plausible that group velocity effects would manifest themselves in the experiments involving tightly focused pulses and thin foils. However, in this case, finite spot size effects are important, and another limiting factor, the transverse expansion of the target, may dominate over the group velocity effect. As the laser pulse diffracts after passing the focus, the target expands accordingly due to the transverse intensity profile of the laser. Due to this expansion, the areal density of the target decreases, making it transparent for radiation and effectively terminating the acceleration. The off-normal incidence of the laser on the target, due either to the experimental setup, or to the deformation of the target, will also lead to establishing a limit on maximum ion energy.
Phase coexistence and domain configuration in Pb(Mg1/3Nb2/3)O3-0.34PbTiO3 single crystal revealed by synchrotron-based X-ray diffractive three-dimensional reciprocal space mapping and piezoresponse force microscopy
Authors: Wang Ruixue , Xu Han , Yang Bin , Luo Zhenlin , Sun Enwei , Zhao Jiangtao , Zheng Limei , Dong Yongqi , Zhou Hua , Ren Yang , Gao Chen , Cao Wenwu
Published: April 2016

The crystalline phases and domain configuration in the morphotropic phase boundary composition Pb(Mg1/3Nb2/3)O3-0.34PbTiO3 (PMN-0.34PT) single crystal have been investigated by synchrotron-based X-ray 3D Reciprocal Space Mapping (3D-RSM) and Piezoresponse Force Microscopy. The coexistence of tetragonal (T) and monoclinic MC phases in this PMN-0.34PT single crystal is confirmed. The affiliation of each diffraction spot in the 3D-RSM was identified with the assistance of qualitative simulation. Most importantly, the twinning structure between different domains in such a mixed phase PMN-PT crystal is firmly clarified, and the spatial distribution of different twin domains is demonstrated. In addition, the lattice parameters of T and MC phases in PMN-0.34PT single crystal as well as the tilting angles of crystal lattices caused by the interfacial lattice mismatch are determined.
Measurement of deposition rate and ion energy distribution in a pulsed dc magnetron sputtering system using a retarding field analyzer with embedded quartz crystal microbalance
Authors: Sharma Shailesh , Gahan David , Scullin Paul , Doyle James , Lennon Jj , Vijayaraghavan Rajani K. , Daniels Stephen , Hopkins M. B.
Published: April 2016

A compact retarding field analyzer with embedded quartz crystal microbalance has been developed to measure deposition rate, ionized flux fraction, and ion energy distribution arriving at the substrate location. The sensor can be placed on grounded, electrically floating, or radio frequency (rf) biased electrodes. A calibration method is presented to compensate for temperature effects in the quartz crystal. The metal deposition rate, metal ionization fraction, and energy distribution of the ions arriving at the substrate location are investigated in an asymmetric bipolar pulsed dc magnetron sputtering reactor under grounded, floating, and rf biased conditions. The diagnostic presented in this research work does not suffer from complications caused by water cooling arrangements to maintain constant temperature and is an attractive technique for characterizing a thin film deposition system.
Asymmetric and symmetric absorption peaks observed in infrared spectra of CO2 adsorbed on TiO2 nanotubes
Authors: Yamakawa Koichiro , Sato Yoshinori , Fukutani Katsuyuki
Published: April 2016

Infrared spectra of CO2 physisorbed on titania nanotubes (TiNTs), predominantly in the anatase polymorph, were measured at 81 K. Asymmetric and symmetric absorption peaks due to the antisymmetric stretch vibration (ν3) of CO2 were observed at 2340 cm−1 and 2350 cm−1, respectively. On the basis of the exposure- and time-dependence of the spectrum, the 2340 cm−1 peak was attributed to CO2 at the defective sites related to subsurface O vacancies (Vos) while the 2350 cm−1 peak was assigned to that at the fivefold coordinated Ti4+ sites. It was found that the generalized Fano line shape was well fitted to the 2340 cm−1 peak. We also observed an absorption peak at 2372 cm−1, which was attributed to the combination band of ν3 and the external mode of CO2 at Ti4+.
On the accuracy of the Padé-resummed master equation approach to dissipative quantum dynamics
Authors: Chen Hsing-Ta , Berkelbach Timothy C. , Reichman David R.
Published: April 2016

Well-defined criteria are proposed for assessing the accuracy of quantum master equations whose memory functions are approximated by Padé resummation of the first two moments in the electronic coupling. These criteria partition the parameter space into distinct levels of expected accuracy, ranging from quantitatively accurate regimes to regions of parameter space where the approach is not expected to be applicable. Extensive comparison of Padé-resummed master equations with numerically exact results in the context of the spin–boson model demonstrates that the proposed criteria correctly demarcate the regions of parameter space where the Padé approximation is reliable. The applicability analysis we present is not confined to the specifics of the Hamiltonian under consideration and should provide guidelines for other classes of resummation techniques.
Very slow decay of a defect related emission band at 2.4 eV in AlN: Signatures of the Si related shallow DX state
Authors: Lamprecht M. , Grund C. , Neuschl B. , Thonke K. , Bryan Z. , Collazo R. , Sitar Z.
Published: April 2016

We report on a defect related luminescence band at 2.4 eV in aluminum nitride bulk crystals, for which we find strong indications to be related to silicon DX centers. Time resolved photoluminescence spectroscopy using a sub-bandgap excitation reveals two different recombination processes with very long decay times of 13 ms and 153 ms at low temperature. Based on the results of temperature and excitation dependent photoluminescence experiments, the process with the shorter lifetime is assigned to a donor-acceptor pair transition involving the shallow silicon donor state, which can be emptied with a thermal dissociation energy of 65 meV. The slower process with a thermal quenching energy of 15 meV is assigned to the slightly deeper Si DX state known from electron paramagnetic resonance experiments, which is transferred back to the shallow donor state.
Tailoring thermal conductivity of silicon/germanium nanowires utilizing core-shell architecture
Authors: Sarikurt S. , Ozden A. , Kandemir A. , Sevik C. , Kinaci A. , Haskins J. B. , Cagin T.
Published: April 2016

Low-dimensional nanostructured materials show large variations in their thermal transport properties. In this work, we investigate the influence of the core-shell architecture on nanowire (1D) thermal conductivity and evaluate its validity as a strategy to achieve a better thermoelectric performance. To obtain the thermal conductivity values, equilibrium molecular dynamics simulations are conducted for core-shell nanowires of silicon and germanium. To explore the parameter space, we have calculated thermal conductivity values of the Si-core/Ge-shell and Ge-core/Si-shell nanowires having different cross-sectional sizes and core contents at several temperatures. Our results indicate that (1) increasing the cross-sectional area of pristine Si and pristine Ge nanowires increases the thermal conductivity, (2) increasing the Ge core size in the Ge-core/Si-shell structure results in a decrease in the thermal conductivity at 300 K, (3) the thermal conductivity of the Si-core/Ge-shell nanowires demonstrates a minima at a specific core size, (4) no significant variation in the thermal conductivity is observed in nanowires for temperatures larger than 300 K, and (5) the predicted thermal conductivity within the frame of applied geometrical constraints is found to be around 10 W/(mK) for the Si and Ge core-shell architecture with a smooth interface. The value is still higher than the amorphous limit (1 W/(mK)). This represents a significant reduction in thermal conductivity with respect to their bulk crystalline and pristine nanowire forms. Furthermore, we observed additional suppression of thermal conductivity through the introduction of interface roughness to Si/Ge core-shell nanowires.
Modeling spatially localized photonic nanojets from phase diffraction gratings
Authors: Geints Yu. E. , Zemlyanov A. A.
Published: April 2016

We investigated numerically the specific spatially localized intense optical structure, a photonic nanojet (PNJ), formed in the near-field scattering of optical radiation at phase diffraction gratings. The finite-difference time-domain technique was employed to study the PNJ key parameters (length, width, focal distance, and intensity) produced by diffraction gratings with the saw-tooth, rectangle, and hemispheric line profiles. Our analysis showed that each type of diffraction gratings produces a photonic jet with unique characteristics. Based on the numerical calculations, we demonstrate that the PNJ could be manipulated in a wide range through the variation of period, duty cycle, and shape of diffraction grating rulings.
Real-time monitoring of graphene patterning with wide-field four-wave mixing microscopy
Authors: Koivistoinen Juha , Aumanen Jukka , Hiltunen Vesa-Matti , Myllyperkiö Pasi , Johansson Andreas , Pettersson Mika
Published: April 2016

The single atom thick two-dimensional graphene is a promising material for various applications due to its extraordinary electronic, optical, optoelectronic, and mechanical properties. The demand for developing graphene based applications has entailed a requirement for development of methods for fast imaging techniques for graphene. Here, we demonstrate imaging of graphene with femtosecond wide-field four-wave mixing microscopy. The method provides a sensitive, non-destructive approach for rapid large area characterization of graphene. We show that the method is suitable for online following of a laser patterning process of microscale structures on single-layer graphene.
Enhanced monolayer MoS2/InP heterostructure solar cells by graphene quantum dots
Authors: Wang Peng , Lin Shisheng , Ding Guqiao , Li Xiaoqiang , Wu Zhiqian , Zhang Shengjiao , Xu Zhijuan , Xu Sen , Lu Yanghua , Xu Wenli , Zheng Zheyang
Published: April 2016

We demonstrate significantly improved photovoltaic response of monolayer molybdenum disulfide (MoS2)/indium phosphide (InP) van der Waals heterostructure induced by graphene quantum dots (GQDs). Raman and photoluminescence measurements indicate that effective charge transfer takes place between GQDs and MoS2, which results in n-type doping of MoS2. The doping effect increases the barrier height at the MoS2/InP heterojunction, thus the averaged power conversion efficiency of MoS2/InP solar cells is improved from 2.1% to 4.1%. The light induced doping by GQD provides a feasible way for developing more efficient MoS2 based heterostructure solar cells.
Optical pump-terahertz probe analysis of long-lived d-electrons and relaxation to self-trapped exciton states in MnO
Authors: Nishitani Junichi , Nagashima Takeshi , Lippmaa Mikk , Suemoto Tohru
Published: April 2016

The dynamics of photoexcited electrons in various excited d-states was investigated in a transition metal oxide MnO by tunable optical pump-terahertz probe measurements. Photoexcited electrons in the lowest excited d-state showed the longest relaxation time among the three excited d-states that are accessible in MnO at room temperature. The relaxation rate in the lowest excited d-state showed a drastic increase below the Neel temperature TN = 120 K in MnO. We conclude that this increase is caused by the appearance of a decay channel related to magnetic-excitation-assisted photoluminescence from self-trapped exciton (STE) states. The opening of relaxation channels to the STE states in an antiferromagnetic phase suggests that it may be possible to control photocarrier lifetime by magnetic order in transition metal oxides.
Sliding droplets on hydrophilic/superhydrophobic patterned surfaces for liquid deposition
Authors: Chang Bo , Zhou Quan , Ras Robin H. A. , Shah Ali , Wu Zhigang , Hjort Klas
Published: April 2016

A facile gravity-induced sliding droplets method is reported for deposition of nanoliter sized droplets on hydrophilic/superhydrophobic patterned surface. The deposition process is parallel where multiple different liquids can be deposited simultaneously. The process is also high-throughput, having a great potential to be scaled up by increasing the size of the substrate.
Bias field free tunability of microwave properties based on geometrically controlled isolated permalloy nanomagnets
Authors: Haldar Arabinda , Adeyeye Adekunle Olusola
Published: April 2016

We have investigated the static and dynamic properties of two lithographically patterned bi-stable nanomagnets. Different ground magnetic states were realized using a simple in-plane field initialization technique. These states were directly imaged with magnetic force microscopy. Using the broadband ferromagnetic spectroscopy, we show that different magnetic ground states are associated with distinct microwave absorption spectra due to the variation of the internal magnetic field leading to large shift between the absorption spectra. Our experimental observations are in good agreement with micromagnetic simulations which also indicate the possibility of sub-ns switching between magnetic states using a rectangular pulse field.
A mixed-methods study of vocabulary-related strategic behaviour in informal L2 contact
Authors: Briggs Jessica Grace
Published: April 2016

This study investigated the vocabulary strategies of n = 241 mixed-L1, adult study abroad learners of English in informal (i.e. out-of-class) second language (L2) contact. A questionnaire determined the extent to which the sample identified with 28 vocabulary strategies. The Opportunities With Language Simulator, an innovative research tool comprising computer simulations of informal L2 contact scenarios, was used as a stimulus in semi-structured interviews with a subsample of n = 36 participants. The questionnaire data revealed that the strategies most identified with pertained to the use of new words/phrases. These strategies were applicable in multiple scenarios and available to a range of different learners. The interview data exposed a wealth of contextual factors (e.g. physical setting) and learner-specific features (e.g.) perceptions of the L2 culture) that influenced whether/how vocabulary strategies were employed. A conceptual model of influencing factors on strategic behavior in informal L2 contact is posited, and recommendations made for future research.
Kinetics on the turbidity change of wheat starch during its retrogradation
Authors: Fukuzawa Soma , Ogawa Takenobu , Nakagawa Kyuya , Adachi Shuji
Published: April 2016

Wheat starch dispersions of 10–40% (w/w) were gelatinized and the change in turbidity of each solution during storage was measured in the 400–1100 nm wavelength range. The relative transmittance, defined as the ratio of transmittance at any storage time to that at the initial time, decreased when the solutions were stored at 5 and 30 °C; the decrease, reflecting the progress of retrogradation, was larger at 5 °C than at 30 °C. Most of the changes in relative transmission taking place over 14 days were achieved during the first 90 min. The change in the relative transmittance is inversely proportional to the energy required for deformation. The kinetics on change in relative transmittance can be expressed by Weibull equation. The larger rate constant at higher starch concentration could be ascribed to the state of the starch granules, which depended on starch concentration.
Osteopontin ablation ameliorates muscular dystrophy by shifting macrophages to a pro-regenerative phenotype
Authors: Capote Joana , Kramerova Irina , Martinez Leonel , Vetrone Sylvia , Barton Elisabeth R. , Sweeney H. Lee , Miceli M. Carrie , Spencer Melissa J.
Published: April 2016

In the degenerative disease Duchenne muscular dystrophy, inflammatory cells enter muscles in response to repetitive muscle damage. Immune factors are required for muscle regeneration, but chronic inflammation creates a profibrotic milieu that exacerbates disease progression. Osteopontin (OPN) is an immunomodulator highly expressed in dystrophic muscles. Ablation of OPN correlates with reduced fibrosis and improved muscle strength as well as reduced natural killer T (NKT) cell counts. Here, we demonstrate that the improved dystrophic phenotype observed with OPN ablation does not result from reductions in NKT cells. OPN ablation skews macrophage polarization toward a pro-regenerative phenotype by reducing M1 and M2a and increasing M2c subsets. These changes are associated with increased expression of pro-regenerative factors insulin-like growth factor 1, leukemia inhibitory factor, and urokinase-type plasminogen activator. Furthermore, altered macrophage polarization correlated with increases in muscle weight and muscle fiber diameter, resulting in long-term improvements in muscle strength and function in mdx mice. These findings suggest that OPN ablation promotes muscle repair via macrophage secretion of pro-myogenic growth factors.
Gankyrin has an antioxidative role through the feedback regulation of Nrf2 in hepatocellular carcinoma
Authors: Yang Chun , Tan Ye-xiong , Yang Guang-zhen , Zhang Jian , Pan Yu-fei , Liu Chen , Fu Jing , Chen Yao , Ding Zhi-wen , Dong Li-wei , Wang Hong-yang
Published: April 2016

Oxidative stress status has a key role in hepatocellular carcinoma (HCC) development and progression. Normally, reactive oxygen species (ROS) levels are tightly controlled by an inducible antioxidant program that responds to cellular stressors. How HCC cells respond to excessive oxidative stress remains elusive. Here, we identified a feedback loop between gankyrin, an oncoprotein overexpressed in human HCC, and Nrf2 maintaining the homeostasis in HCC cells. Mechanistically, gankyrin was found to interact with the Kelch domain of Keap1 and effectively competed with Nrf2 for Keap1 binding. Increased expression of gankyrin in HCC cells blocked the binding between Nrf2 and Keap1, inhibiting the degradation of Nrf2 by proteasome. Interestingly, accumulation and translocation of Nrf2 increased the transcription of gankyrin through binding to the ARE elements in the promoter of gankyrin. The positive feedback regulation involving gankyrin and Nrf2 modulates a series of antioxidant enzymes, thereby lowering intracellular ROS and conferring a steadier intracellular environment, which prevents mitochondrial damage and cell death induced by excessive oxidative stress. Our results indicate that gankyrin is a regulator of cellular redox homeostasis and provide a link between oxidative stress and the development of HCC.
TREM2-mediated early microglial response limits diffusion and toxicity of amyloid plaques
Authors: Wang Yaming , Ulland Tyler K. , Ulrich Jason D. , Song Wilbur , Tzaferis John A. , Hole Justin T. , Yuan Peng , Mahan Thomas E. , Shi Yang , Gilfillan Susan , Cella Marina , Grutzendler Jaime , DeMattos Ronald B. , Cirrito John R. , Holtzman David M. , Colonna Marco
Published: April 2016

Triggering receptor expressed on myeloid cells 2 (TREM2) is a microglial receptor that recognizes changes in the lipid microenvironment, which may occur during amyloid β (Aβ) accumulation and neuronal degeneration in Alzheimer’s disease (AD). Rare TREM2 variants that affect TREM2 function lead to an increased risk of developing AD. In murine models of AD, TREM2 deficiency prevents microglial clustering around Aβ deposits. However, the origin of myeloid cells surrounding amyloid and the impact of TREM2 on Aβ accumulation are a matter of debate. Using parabiosis, we found that amyloid-associated myeloid cells derive from brain-resident microglia rather than from recruitment of peripheral blood monocytes. To determine the impact of TREM2 deficiency on Aβ accumulation, we examined Aβ plaques in the 5XFAD model of AD at the onset of Aβ-related pathology. At this early time point, Aβ accumulation was similar in TREM2-deficient and -sufficient 5XFAD mice. However, in the absence of TREM2, Aβ plaques were not fully enclosed by microglia; they were more diffuse, less dense, and were associated with significantly greater neuritic damage. Thus, TREM2 protects from AD by enabling microglia to surround and alter Aβ plaque structure, thereby limiting neuritic damage.
Mixing‐Recording Method for the Practical Determination of Physical Properties of Soy Protein Isolate
Authors: Kanamori Jiro
Published: April 2016

The mixing properties of soy protein isolate (SPI) were investigated. The electric current of a kitchen food processor was monitored during the mixing of SPIs to produce dough, and an identical mixing curve was obtained for each SPI. The obtained peak time and peak height of the electric current curve were correlated to the physical properties (solubility and gel strength) of each SPI. The peak time negatively correlated with solubility, and the peak height positively correlated with gel strength. Optical microscopic observations showed that the dough microstructure appeared to be related to the peak time. Moreover, some conditions such as the SPI storage conditions and the ionic strength of the mixing buffer affected the mixing properties. This mixing‐recording method is proposed as a practical tool that could simplify the evaluation of SPI characteristics.
Characterization of Beet curly top virus Strains Circulating in Beet Leafhoppers (Hemiptera: Cicadellidae) in Northeastern Oregon
Authors: Rondon Silvia I. , Roster Mary Sue , Hamlin Launa L. , Green Kelsie J. , Karasev Alexander V. , Crosslin J. M.
Published: April 2016

The beet leafhopper, Circulifer tenellus, is an agriculturally important pest, particularly in the western United States. This insect transmits the Beet curly top virus (BCTV) to multiple crops, including bean, tomato, and pepper. In this study, we investigated the incidence of BCTV in individual leafhoppers collected at several sites in northeastern Oregon during the growing season in 2007, 2008, and 2009. Of the 800 insects tested, 151 (18.9%) were found positive for the virus. Percentage of virus incidence varied from 0% at one location in 2009 to a high of 55.6% for a location sampled in 2008. The complete virus genomes from one virus-positive insect collected in each of the 3 years were determined. BLAST analysis of the BCTV whole-genome sequences from 2007, 2008, and 2009 insects showed 98, 94, and 96% identities with the BCTV-Worland sequence (AY134867), respectively. The BCTV_2008 sequence showed the greatest identity (96%) with another BCTV genomic sequence (JN817383), and was found to be a recombinant between the BCTV-Worland type, representing the majority of the genome (approximately 2.2 kb), and the BCTV-CFH type that provided an approximately 0.8-kb fragment spanning replication-related genes C1 and C2. This area of the BCTV genome, between the C1 and C2 genes, was previously found to carry symptom determinants of the virus, and the data may suggest more severe effects of BCTV during the 2008 season. Results indicate that BCTV is common and widespread in C. tenellus in eastern Oregon and that there is substantial genetic diversity among the virus strains present in this important field and vegetable crop-growing region.
Quantitative assessment of insertion sequence impact on bacterial genome architecture
Authors: Adams Mark D. , Bishop Brian , Wright Meredith S.
Published: April 2016

Insertion sequence (IS) elements are important mediators of genome plasticity and can lead to phenotypic changes with evolutionary significance. In multidrug-resistant Acinetobacter baumannii and Klebsiella pneumoniae, IS elements have contributed significantly to the mobilization of genes that encode resistance to antimicrobial drugs. A systematic analysis of IS elements is needed for a more comprehensive understanding of their evolutionary impact. We developed a computational approach (ISseeker) to annotate IS elements in draft genome assemblies and applied the method to analysis of IS elements in all publicly available A. baumannii(>1000) and K. pneumoniae(>800) genome sequences, in a phylogenetic context. Most IS elements in A. baumanniigenomes are species-specific ISAba elements, whereas K. pneumoniaegenomes contain significant numbers of both ISKpn elements and elements that are found throughout the Enterobacteriaceae. A. baumanniigenomes have a higher density of IS elements than K. pneumoniae, averaging ~33 vs ~27 copies per genome. In K. pneumoniae, several insertion sites are shared by most genomes in the ST258 clade, whereas in A. baumannii, different IS elements are abundant in different phylogenetic groups, even among closely related Global Clone 2 strains. IS elements differ in the distribution of insertion locations relative to genes, with some more likely to disrupt genes and others predominantly in intergenic regions. Several genes and intergenic regions had multiple independent insertion events, suggesting that those events may confer a selective advantage. Genome- and taxon-wide characterization of insertion locations revealed that IS elements have been active contributors to genome diversity in both species.
XDSAPP2.0
Authors: Sparta Karine M. , Krug Michael , Heinemann Udo , Mueller Uwe , Weiss Manfred S.
Published: April 2016

XDSAPPis an expert system and graphical user interface (GUI) for the automated processing of diffraction images using theXDSprogram suite and other programs. The latest major update and the extension of the program are presented here. The update includes new features, as well as improvements in the GUI and the underlying decision-making system.XDSAPPis freely available for academic users.
A Johann-type X-ray emission spectrometer at the Rossendorf beamline
Authors: Kvashnina Kristina O. , Scheinost Andreas C.
Published: April 2016

This paper gives a detailed description, including equations, of the Johann-type X-ray emission spectrometer which has been recently installed and tested at the Rossendorf beamline (ROBL) of the European Synchrotron Radiation Facility. The spectrometer consists of a single spherically bent crystal analyzer and an avalanche photodiode detector positioned on the vertical Rowland cycle of 1 m diameter. The hard X-ray emission spectrometer (∼3.5–25 keV) operates at atmospheric pressure and covers the Bragg angles of 65°–89°. The instrument has been tested at high and intermediate incident energies,i.e.at the ZrK-edge and at the AuL3-edge, in the second experimental hutch of ROBL. The spectrometer is dedicated for studying actinides in materials and environmental samples by high-energy-resolution X-ray absorption and X-ray emission spectroscopies.
Spectrum splitting for fast polarization switching of undulator radiation
Authors: Kinjo Ryota , Tanaka Takashi
Published: April 2016

A simple scheme to quickly switch the polarity of circular radiation is proposed, which is based on spectrum splitting of undulator radiation. In this scheme, two helical undulators with opposite helicities are placed tandem in one straight section, both of which are divided into several segments. The optical phases between segments are tuned so that light waves from one of the two undulators are out of phase, while those from the other are in phase. Then the radiation spectrum of the former is split and the intensity at the fundamental photon energy vanishes. As a consequence, the monochromated photon beam at the fundamental energy is circularly polarized with the helicity specified by the in-phase undulator, which can be quickly flipped by tuning the optical phase. Numerical calculations carried out to demonstrate the feasibility of the proposed scheme show that a relatively high degree of circular polarization is expected if the angular acceptance of the beamline is not too large.
Sapphire hard X-ray Fabry–Perot resonators for synchrotron experiments
Authors: Tsai Yi-Wei , Wu Yu-Hsin , Chang Ying-Yi , Liu Wen-Chung , Liu Hong-Lin , Chu Chia-Hong , Chen Pei-Chi , Lin Pao-Te , Fu Chien-Chung , Chang Shih-Lin
Published: April 2016

Hard X-ray Fabry–Perot resonators (FPRs) made from sapphire crystals were constructed and characterized. The FPRs consisted of two crystal plates, part of a monolithic crystal structure of Al2O3, acting as a pair of mirrors, for the backward reflection (0 0 0 30) of hard X-rays at 14.3147 keV. The dimensional accuracy during manufacturing and the defect density in the crystal in relation to the resonance efficiency of sapphire FPRs were analyzed from a theoretical standpoint based on X-ray cavity resonance and measurements using scanning electron microscopic and X-ray topographic techniques for crystal defects. Well defined resonance spectra of sapphire FPRs were successfully obtained, and were comparable with the theoretical predictions.
Assessing Italian wine quality and prices: de gustibus non disputandum est
Authors: Cacchiarelli Luca , Carbone Anna , Esti Marco , Laureti Tiziana , Sorrentino Alessandro
Published: April 2016

Purpose

The paper focuses on high segments of the Italian wine market. The goal is twofold. First, it aims at understanding to what extent wine experts are influenced by specific quality clues. Second, it seeks at assessing the role and effectiveness of different quality clues in the creation of price

Design/methodology/approach

To meet these goals two independent equations are set. The first -estimated via an ordered logit- explaining the rating of a wine with a bunch of attributes of the wine and of its production process. The second equation is a hedonic price model –estimated via an interval regression- where price is a function of a large number of quality clues. The analysis covers 2,523 wines from three Italian Regions as reviewed by Veronelli guide, 2010 edition

Findings

The model estimation results indicates that: i) few attributes seems to systematically impact experts’ judgments; ii) many quality clues are associated with significant price premiums; iii) in some cases consumers give value to quality clues along with Veronelli’s experts while in other cases there is no such alignment

Originality/value

This study advances the literature in two different ways. First, modeling two distinct equations that describe the factors affecting, on the one side, experts’ evaluations, and, on the other side, market prices. Second, as it assesses the price premium associated to quality clues whose value hasn’t been considered so far in hedonic price models. We affirm that assessing factors that influence experts brings more transparency and a better segmentation in the guide market and in all experts’ quality signals.
Assessing the table grape supply chain performance in China - a value chain analysis perspective
Authors: Deng Lei , Wang Ruimei , Dong Tian , Feng Jianying , Weisong Mu
Published: April 2016

Purpose

The paper aims to understand the cost-benefits, financial performance and relationships of the key actors in the table grape supply chain by using value chain analysis method.

Design/methodology/approach

This study presents the result of analysis on financial performance of key actors in three table grape supply chains and the relationship among them using value chain analysis. The table grape supply chain was analyzed using data collected from a field survey in 5 regions of China. The key actors of these chains were interviewed. The costs, benefits, operational and financial performance of supply chain actors were analyzed.

Findings

The results show that, despite receiving the highest proportion of total net profit and making the highest value creation, vinegrowers are facing fluctuant and uncertain commercial returns due to the production and market risks, fluctuation of farm-gate price and the buyer dominant relationship with wholesalers. Moreover, although it is profitable to all key actors, table grape supply chain still faces several challenges including unorganized and dispersed production systems, power asymmetry and lack of information sharing, all of which are the barriers to the improvement of the whole chain performance and the long term sustainability of this important industry.

Originality/value

This paper not only helps to understand the relationship among the key actors and the critical factors impacting on the whole chain performance, but also offer useful guidance for the policy makers and key actors to achieve further improvement of the table grape supply chain performance and provide valuable implications for the future studies on agriculture products.
An application of the theory of planned behaviour to predict intention to consume African indigenous foods in Kenya
Authors: Gakobo Thomas Waweru , Jere Mlenga G.
Published: April 2016

Purpose

African indigenous foods have a special place and role in many African cultures for the sustenance of life and provisions food substances and health. However, it has been observed that consumption of these foods is declining. The purpose of this study is to establish the determinants of consumption intentions of African indigenous foods in Kenya using the theory of planned behaviour.

Design/methodology/approach

A stratified random sample of 319 respondents drawn from Nairobi County was surveyed using a self-completion instrument. Partial least squares analysis was used to test the hypotheses regarding the relationship between the predictor constructs (namely; personal attitude towards African indigenous foods, subjective norm, and perceived behaviour control) and consumption intentions.

Findings

All the predictor constructs were found to positively influence consumption intention and collectively explained 62.3% of the variance in consumption intention for African indigenous foods. There is a discrepancy between our findings on intention to consume AIFs and the reported declining consumption. Marketers and policy makers should address factors in the intention-consumption behaviour relation in addition to focusing on the antecedents of intention

Originality/value

This study employs the theory of planned behaviour to investigate the determinants of consumption intention for African indigenous foods in Kenya.
Should Management Practice Adapt to Cultural Values? The Evidence Against Power Distance Adaptation
Authors: Rao Alaka N. , Pearce Jone L.
Published: April 2016

Purpose

We focus on the cultural concept of power distance to test whether or not culture-practice fit or universal supervisory practices are associated with team collaboration, innovation, current and future team performance. This test is possible because power distance is conceptually deconstructed and scales developed that reliably and validly differentiate between the societal level values and workplace practices. Next, drawing on these measures, we test the culture-fit-vs.-universal practices hypotheses in a sample of ethnically similar employees dispersed across the United States and India.

Design/methodology/approach

Data were collected from a survey administered to employees and their supervisors in a Non-Western Multinational Corporation.

Findings

We find support for the universal-practices perspective in this study. Those Indian and local managers who were low in interpersonal power distance, regardless of their subordinates’ societal power-distance cultural values had better team collaboration, innovation, and future performance. Trust in fellow team members was found to mediate these relationships.

Originality/value

Findings from this study contribute to our understanding of power distance, and also provide insight into the central question of when and how management practices should be adapted to local cultures.
Community connections, community collections
Authors: Gwynn David
Published: April 2016

Purpose

This paper aims to explore library–community collaboration from both a theoretical and practical perspective, highlighting successful collaborative strategies and projects and illustrating important considerations for libraries that are considering community partnerships.

Design/methodology/approach

This paper consists of a literature review and several “capsule” case studies of projects completed at one academic library to illustrate principles that can result in successful collaborative projects.

Findings

Library–community collaboration presents significant benefits if the needs and priorities of all collaborating partners are taken into account. Successful projects will use the strengths of one partner to balance the weaknesses of another, will be based on shared goals, will offer credit to all partners and will result in stronger relationships for all involved.

Originality/value

Although library–community partnerships are not uncommon, many of these partnerships are housed in public libraries or involve only large, institutional players. This paper explores several non-traditional academic library initiatives involving youth service learning and outreach to smaller community groups that might otherwise be ignored by large university libraries.
Digital newspaper preservation through collaboration
Authors: Krahmer Ana
Published: April 2016

Purpose

The Texas Digital Newspaper Program (TDNP) supports newspaper preservation and access for any title in Texas, from any date, any location and representing any community. As an active member of the Texas Press Association, TDNP also supports large-scale preservation of born-digital newspaper PDF issues for member publishers. This paper aims to explore how the early days of TDNP built a strong foundation of collaboration and support for large-scale preservation projects, including support for preserving a state press association PDF newspaper collection.

Design/methodology/approach

This paper is a case study of a collaborative endeavor to create a large-scale, statewide digital newspaper preservation hub in Texas. This paper details how individual partnerships led to new and larger partnerships. Figures and tables represent numbers of partner institutions served, numbers of newspapers preserved and screenshots of how these items appear within collections on the digital repository environment of The Portal to Texas History. This paper concludes with recommendations for groups interested in developing their own collaborative projects.

Findings

As a case study, the data explored include numbers of partnering institutions, materials contributed by partnering institutions and how these numbers help to forward the TDNP agenda.

Practical Implications

The final recommendations are lessons learned through collaboration, and the implications are real-world advice from the partners developed through the TDNP.

Originality/value

Hosting over 3.25 million pages of newspapers, the TDNP has become an enormous hub of newspaper preservation in Texas, and it is unique in the numbers of partners it supports and the numbers of pages it is able to host for free access via The Portal to Texas History. This paper is intended to help other groups across the world build their own collaborative preservation efforts, and it offers pragmatic advice derived from hands-on experience.
Librarians prepare to help patrons overcome the digital divide in Northeast Florida
Authors: O’Neill Jennifer
Published: April 2016

Purpose

The purpose of this innovative, highly replicable paper is to teach library staff learn to use mobile apps to lead and assist patrons and effectively market library services.

Design/methodology/approach

This web-based class introduces participants to one mobile app a week. Participants must download the app to an Apple or Droid device, complete an activity and answer a few thought-provoking questions. Participants’ time commitment does not exceed one hour per week.

Findings

Participants were proud and excited to have mastered their mobile device and 23 mobile apps. They reported that they planned to create programs to teach apps to patrons, market their services using apps and continue to stay current with technological advances.

Researchlimitations/implications

Participants need to have access to a mobile device.

Practicalimplications

Library directors allowed staff to use an hour a week of work time to complete this program.

Socialimplications

Library staff enjoyed talking about the apps and working together. Each Monday morning when a new app was revealed, they competed to be the first to complete the activity and post answers to the questions online. They had fun.

Originality/value

This program allows customization. It was customized to meet the strategic needs of the authors’ organization, encouraging a sense of community among participants, marketing their services and highlighting member libraries that were already using some of the apps well. (One of our libraries had their own app and that became one of the Things.)
Roads increase population growth rates of a native leaf‐cutter ant in Neotropical savannahs
Authors: Vieira‐Neto Ernane H. M. , Vasconcelos Heraldo L. , Bruna Emilio M.
Published: April 2016

A challenge in applied ecology is understanding the responses of native species to roads, which are ubiquitous drivers of environmental heterogeneity. While most studies highlight their negative effects, the potential for native species to increase in abundance near roads has been underappreciated, and the demographic mechanisms underlying abundance changes remain unclear. Elucidating these mechanisms requires first determining how demographic vital rates and life‐history stages interact to influence population growth. One can then assess how roads alter the relative importance of the alternative demographic pathways – increased performance of early vs. late life stages – suggested as the principal drivers of increased population growth.

We parameterized demographic models with 3 years of census data and conducted perturbation analyses to evaluate how proximity to roads altered abundance and demography. To do so, we used the leaf‐cutter ant Atta laevigata as our model organism. Leaf‐cutters are native ecosystem engineers and dominant herbivores in Neotropical ecosystems and also amongst the longest lived insects in nature. Our study was conducted in Cerrado savannahs, where road networks are rapidly expanding and Atta species are major agricultural pests.

We found that 35–45% of adult colonies were located within 15 m of roads, which is significantly closer than expected at random. Population growth rates (λ) were >1 both near and far from roads, but λ near roads were significantly (41%) higher. Elasticities of λ to early survival and growth rates were proportionally much higher than those of adult stages, irrespective of habitat. Life‐table response experiment results indicate that the higher λ near roads was due primarily to the much higher colonization and early‐life performance there.

Synthesis and applications. Road networks are proliferating throughout biodiversity‐rich regions. Developing conservation and management guidelines for species whose abundance is altered by roads requires understanding the demographic mechanisms that underpin these changes. We demonstrate that the higher growth rate of roadside Atta laevigata populations is due to increased early‐life performance. Thus, the expansion of road networks could have major ecological and economic consequences by facilitating the increased abundance of ecosystem engineers and agricultural pests. Accounting for A. laevigata early life stages and careful planning of road placement should improve management strategies of protected areas and agricultural systems in Neotropical savannahs.