bluuebunny/crossref_metadata_2025 huggingface dataset:
On the relevance of magnetohydrodynamic pumping in solar coronal loop simulation experiments
Authors: Tenfelde J. , Kempkes P. , Mackel F. , Ridder S. , Stein H. , Tacke T. , Soltwisch H.
Published: July 2012

A magnetohydrodynamic pumping mechanism was proposed by Bellan [Phys. Plasmas 10, 1999 (2003)] to explain the formation of highly collimated plasma-filled magnetic flux tubes in certain solar coronal loop simulation experiments. In this paper, measurements on such an experiment are compared to the predictions of Bellan’s pumping and collimation model. Significant discrepancies between theoretical implications and experimental observations have prompted more elaborate investigations by making use of pertinent modifications of the experimental device. On the basis of these studies, it is concluded that the proposed MHD pumping mechanism does not play a crucial role for the formation and temporal evolution of the arched plasma structures that are generated in the coronal loop simulation experiments under consideration.
Crystal structure, local structure, and defect structure of Pr-doped SrTiO3
Authors: Sluchinskaya I. A. , Lebedev A. I. , Erko A.
Published: July 2012

X-ray diffraction studies showed that the structure of (Sr1−xPrx)TiO3 solid solutions at 300 K changes from the cubic Pm3m to the tetragonal I4/mcm with increasing x. The analysis of XANES and EXAFS spectra of the solid solutions revealed that Pr ions are predominantly in the 3+ oxidation state, they substitute for Sr atoms and are on-center regardless of the preparation conditions. The weak dependence of the lattice parameter in (Sr1−xPrx)TiO3 on the Pr concentration was explained by the competition between the relaxation of the Sr–O bond length, which results from the difference in ionic radii of Sr and Pr ions, and the repulsion of positively charged Pr3+ and Ti4+ ions. It was shown that the most important defects in the crystals are charged Sr vacancies and SrO planar faults; praseodymium does not enter the Sr sites in the planar faults.
Transparent Ti-In-Sn-O multicomponent anodes for highly efficient phosphorescent organic light emitting diodes
Authors: Lim Jong-Wook , Jun Kang Seong , Lee Sunghun , Kim Jang-Joo , Kim Han-Ki
Published: July 2012

We report on transparent Ti-In-Sn-O (TITO) multicomponent anodes prepared by co-sputtering anatase TiO2−x and ITO targets to produce highly efficient phosphorescent organic light emitting diodes (OLEDs). In spite of the incorporation of low cost TiO2, the crystalline TITO electrode annealed at temperature of 600 °C showed a sheet resistance of 18.06 Ω/sq, an optical transmittance of 87.96% at a wavelength of 550 nm, and a work function of 4.71 eV comparable to conventional ITO electrode. Both the quantum (21.69%) and power efficiencies (90.92 lm/W) of the phosphorescent OLED fabricated on the TITO anode were higher than those of the OLED with the reference ITO anode due to the high transparency of the TITO electrodes. This indicates that the TITO electrode is a promising indium-saving electrode that can replace high-cost ITO electrodes in the manufacture of low-cost, highly efficient phosphorescent OLEDs.
Note: Microsecond long atomistic simulation of supercooled water
Authors: Shevchuk Roman , Rao Francesco
Published: July 2012

A 3 μs long molecular dynamics simulation of the TIP4P-Ew water model is presented to investigate the relaxation properties of an atomistic model in the supercooled region below the temperature of homogeneous nucleation. This is an effort towards a better understanding of the equilibrium properties of the liquid phase of supercooled water. Our results indicate that the distribution of several thermodynamic and structural quantities equilibrate on a μs timescale before nucleation to ice occurs.
Graphene radio: Detecting radiowaves with a single atom sheet
Authors: Dragoman M. , Neculoiu D. , Cismaru A. , Deligeorgis G. , Konstantinidis G. , Dragoman D.
Published: July 2012

We present the experimental evidence of RF demodulation by a graphene monolayer embedded in a coplanar structure. The demodulator was tested in the frequency range from 100 MHz to 25 GHz using amplitude modulated input signals. An input power of 0 dBm (1 mW) was used, which is the typical power emitted for short range wireless communication systems, such as Bluetooth. The graphene demodulator exhibits good signal responsivity in the frequency range associated to industrial, scientific and medical radio band with a peak of 1100 V/W at 3.5 GHz.
Enhanced magnetic anisotropy of Ni nanowire arrays fabricated on nano-structured silicon templates
Authors: Granitzer P. , Rumpf K. , Ohta T. , Koshida N. , Reissner M. , Poelt P.
Published: July 2012

The magnetic function of a Ni-nanowire/silicon-template system has been explored in corporation with an advanced process. Arrays of nanopores with a mean diameter of 35 nm have been fabricated by anodization of silicon wafers under an external magnetic field (8 T) perpendicular to the substrate. Due to a guided supply of holes from the substrate during the anodization, well controlled straight nanopores have been formed with a high aspect ratio, and then isolated Ni nanowires have been grown along these nanopores by electrodeposition. The fabricated samples show a significantly enhanced magnetic anisotropy with little crosstalk between adjacent pores.
Diagnosis of gas temperature, electron temperature, and electron density in helium atmospheric pressure plasma jet
Authors: Chang Zheng-Shi , Zhang Guan-Jun , Shao Xian-Jun , Zhang Zeng-Hui
Published: July 2012

The optical emission spectra of helium atmospheric pressure plasma jet (APPJ) are captured with a three grating spectrometer. The grating primary spectrum covers the whole wavelength range from 200 nm to 900 nm, with the overlapped grating secondary spectrum appearing from 500 nm to 900 nm, which has a higher resolution than that of the grating primary spectrum. So the grating secondary spectrum of OH (A2∑ +(υ′ = 0) → X2П(υ″ = 0)) is employed to calculate the gas temperature (Tg) of helium APPJ. Moreover, the electron temperature (Te) is deduced from the Maxwellian electron energy distribution combining with Tg, and the electron density (ne) is extracted from the plasma absorbed power. The results are helpful for understanding the physical property of APPJs.
Study of Rayleigh–Taylor growth in directly driven cryogenic-deuterium targets
Authors: Hager J. D. , Smalyuk V. A. , Hu S. X. , Knauer J. P. , Meyerhofer D. D. , Sangster T. C.
Published: July 2012

Direct-drive, Rayleigh–Taylor growth experiments in liquid deuterium (D2) were performed on the OMEGA laser [T. R. Boehly et al., Opt. Commun. 133, 495 (1997)] using planar cryogenic targets at a laser intensity of ∼4 × 1014 W/cm2. These are the first Rayleigh–Taylor measurements in deuterium at conditions relevant to inertial confinement fusion using a mass preimposed initial modulation. The measured modulation optical depths are in agreement with the 2D hydrodynamics code DRACO using flux-limited local thermal transport, providing an important step in the experimental validation of simulations for direct-drive ignition.
Toroidal curvature induced screening of external fields by a resistive plasma response
Authors: Liu Yueqiang , Connor J. W. , Cowley S. C. , Ham C. J. , Hastie R. J. , Hender T. C.
Published: July 2012

Within the single fluid theory for a toroidal, resistive plasma, the favorable average curvature effect [Glasser et al., Phys. Fluids 18, 875 (1975)], which is responsible for the strong stabilization of the classical tearing mode at finite pressure, can also introduce a strong screening effect to the externally applied resonant magnetic field. Contrary to conventional understanding, this screening, occurring at slow plasma rotation, is enhanced when decreasing the plasma flow speed. The plasma rotation frequency, below which this screening effect is observed, depends on the plasma pressure and resistivity. For the simple toroidal case considered here, the toroidal rotation frequency has to be below ∼10−5ωA, with ωA being the Alfvén frequency. In addition, the same curvature effect leads to enhanced toroidal coupling of poloidal Fourier harmonics inside the resistive layer, as well as reversing the sign of the electromagnetic torque at slow plasma flow.
Behavior of liquid plugs at bifurcations in a microfluidic tree network
Authors: Vertti-Quintero Nadia , Song Yu , Manneville Paul , Baroud Charles N.
Published: July 2012

Flows in complex geometries, such as porous media or biological networks, often contain plugs of liquid flowing within air bubbles. These flows can be modeled in microfluidic devices in which the geometric complexity is well defined and controlled. We study the flow of wetting liquid plugs in a bifurcating network of micro-channels. In particular, we focus on the process by which the plugs divide as they pass each bifurcation. The key events are identified, corresponding to large modifications of the interface curvature, the formation of new interfaces, or the division of a single interface into two new ones. The timing of the different events and the amplitude of the curvature variations are analyzed in view of the design of an event-driven model of flow in branching micro-networks. They are found to collapse onto a master curve dictated by the network geometry.
Polarizabilities of Li and Na in Debye plasmas
Authors: Li H. W. , Kar Sabyasachi
Published: July 2012

We have carried out calculations to investigate the effect of Debye plasmas on the dipole, quadrupole, octupole polarizabilities of lithium and sodium atoms using the symplectic algorithm in the framework of the pseudo-state summation technique. The polarizabilities of alkali-metal atoms for various Debye lengths are reported for the first time in the literature. The behavior of the transition energies and oscillator strengths for Li and Na in plasma environments is also presented. In free atomic cases, our calculated results are in good agreement with the reported theoretical and experimental results.
Observation of intermediate bands in Eu3+ doped YPO4 host: Li+ ion effect and blue to pink light emitter
Authors: Parchur Abdul Kareem , Prasad Amresh Ishawar , Rai Shyam Bahadur , Tewari Raghvendra , Sahu Ranjan Kumar , Okram Gunadhor Singh , Singh Ram Asaray , Ningthoujam Raghumani Singh
Published: July 2012

This article explores the tuning of blue to pink colour generation from Li+ ion co-doped YPO4:5Eu nanoparticles prepared by polyol method at ∼100-120 °C with ethylene glycol (EG) as a capping agent. Interaction of EG molecules capped on the surface of the nanoparticles and/or created oxygen vacancies induces formation of intermediate/mid gap bands in the host structure, which is supported by UV-Visible absorption data. Strong blue and pink colors can be observed in the cases of as-prepared and 500 °C annealed samples, respectively. Co-doping of Li+ enhances the emission intensities of intermediate band as well as Eu3+. On annealing as-prepared sample to 500 °C, the intermediate band emission intensity decreases, whereas Eu3+ emission intensity increases suggesting increase of extent of energy transfer from the intermediate band to Eu3+ on annealing. Emission intensity ratio of electric to magnetic dipole transitions of Eu3+ can be varied by changing excitation wavelength. The X-ray photoelectron spectroscopy (XPS) study of as-prepared samples confirms the presence of oxygen vacancies and Eu3+ but absence of Eu2+. Dispersed particles in ethanol and polymer film show the strong blue color, suggesting that these materials will be useful as probes in life science and also in light emitting device applications.
Field dependent transition to the non-linear regime in magnetic hyperthermia experiments: Comparison between maghemite, copper, zinc, nickel and cobalt ferrite nanoparticles of similar sizes
Authors: Verde E. L. , Landi G. T. , Carrião M. S. , Drummond A. L. , Gomes J. A. , Vieira E. D. , Sousa M. H. , Bakuzis A. F.
Published: July 2012

Further advances in magnetic hyperthermia might be limited by biological constraints, such as using sufficiently low frequencies and low field amplitudes to inhibit harmful eddy currents inside the patient's body. These incite the need to optimize the heating efficiency of the nanoparticles, referred to as the specific absorption rate (SAR). Among the several properties currently under research, one of particular importance is the transition from the linear to the non-linear regime that takes place as the field amplitude is increased, an aspect where the magnetic anisotropy is expected to play a fundamental role. In this paper we investigate the heating properties of cobalt ferrite and maghemite nanoparticles under the influence of a 500 kHz sinusoidal magnetic field with varying amplitude, up to 134 Oe. The particles were characterized by TEM, XRD, FMR and VSM, from which most relevant morphological, structural and magnetic properties were inferred. Both materials have similar size distributions and saturation magnetization, but strikingly different magnetic anisotropies. From magnetic hyperthermia experiments we found that, while at low fields maghemite is the best nanomaterial for hyperthermia applications, above a critical field, close to the transition from the linear to the non-linear regime, cobalt ferrite becomes more efficient. The results were also analyzed with respect to the energy conversion efficiency and compared with dynamic hysteresis simulations. Additional analysis with nickel, zinc and copper-ferrite nanoparticles of similar sizes confirmed the importance of the magnetic anisotropy and the damping factor. Further, the analysis of the characterization parameters suggested core-shell nanostructures, probably due to a surface passivation process during the nanoparticle synthesis. Finally, we discussed the effect of particle-particle interactions and its consequences, in particular regarding discrepancies between estimated parameters and expected theoretical predictions.
Neuregulin and dopamine modulation of hippocampal gamma oscillations is dependent on dopamine D4 receptors
Authors: Andersson Richard H. , Johnston April , Herman Paul A. , Winzer-Serhan Ursula H. , Karavanova Irina , Vullhorst Detlef , Fisahn André , Buonanno Andres
Published: July 2012

The neuregulin/ErbB signaling network is genetically associated with schizophrenia and modulates hippocampal γ oscillations—a type of neuronal network activity important for higher brain processes and altered in psychiatric disorders. Because neuregulin-1 (NRG-1) dramatically increases extracellular dopamine levels in the hippocampus, we investigated the relationship between NRG/ErbB and dopamine signaling in hippocampal γ oscillations. Using agonists for different D1- and D2-type dopamine receptors, we found that the D4 receptor (D4R) agonist PD168077, but not D1/D5 and D2/D3 agonists, increases γ oscillation power, and its effect is blocked by the highly specific D4R antagonist L-745,870. Using double in situ hybridization and immunofluorescence histochemistry, we show that hippocampal D4R mRNA and protein are more highly expressed in GAD67-positive GABAergic interneurons, many of which express the NRG-1 receptor ErbB4. Importantly, D4 and ErbB4 receptors are coexpressed in parvalbumin-positive basket cells that are critical for γ oscillations. Last, we report that D4R activation is essential for the effects of NRG-1 on network activity because L-745,870 and the atypical antipsychotic clozapine dramatically reduce the NRG-1–induced increase in γ oscillation power. This unique link between D4R and ErbB4 signaling on γ oscillation power, and their coexpression in parvalbumin-expressing interneurons, suggests a cellular mechanism that may be compromised in different psychiatric disorders affecting cognitive control. These findings are important given the association of aDRD4polymorphism with alterations in attention, working memory, and γ oscillations, and suggest potential benefits of D4R modulators for targeting cognitive deficits.
Protein folding kinetics and thermodynamics from atomistic simulation
Authors: Piana Stefano , Lindorff-Larsen Kresten , Shaw David E.
Published: July 2012

Advances in simulation techniques and computing hardware have created a substantial overlap between the timescales accessible to atomic-level simulations and those on which the fastest-folding proteins fold. Here we demonstrate, using simulations of four variants of the human villin headpiece, how simulations of spontaneous folding and unfolding can provide direct access to thermodynamic and kinetic quantities such as folding rates, free energies, folding enthalpies, heat capacities, Φ-values, and temperature-jump relaxation profiles. The quantitative comparison of simulation results with various forms of experimental data probing different aspects of the folding process can facilitate robust assessment of the accuracy of the calculations while providing a detailed structural interpretation for the experimental observations. In the example studied here, the analysis of folding rates, Φ-values, and folding pathways provides support for the notion that a norleucine double mutant of villin folds five times faster than the wild-type sequence, but following a slightly different pathway. This work showcases how computer simulation has now developed into a mature tool for the quantitative computational study of protein folding and dynamics that can provide a valuable complement to experimental techniques.
Mitochondrial Ca
2+
uptake contributes to buffering cytoplasmic Ca
2+
peaks in cardiomyocytes
Authors: Drago Ilaria , De Stefani Diego , Rizzuto Rosario , Pozzan Tullio
Published: July 2012

Mitochondrial ability of shaping Ca
2+
signals has been demonstrated in a large number of cell types, but it is still debated in heart cells. Here, we take advantage of the molecular identification of the mitochondrial Ca
2+
uniporter (MCU) and of unique targeted Ca
2+
probes to directly address this issue. We demonstrate that, during spontaneous Ca
2+
pacing, Ca
2+
peaks on the outer mitochondrial membrane (OMM) are much greater than in the cytoplasm because of a large number of Ca
2+
hot spots generated on the OMM surface. Cytoplasmic Ca
2+
peaks are reduced or enhanced by MCU overexpression and siRNA silencing, respectively; the opposite occurs within the mitochondrial matrix. Accordingly, the extent of contraction is reduced by overexpression of MCU and augmented by its down-regulation. Modulation of MCU levels does not affect the ATP content of the cardiomyocytes. Thus, in neonatal cardiac myocytes, mitochondria significantly contribute to buffering the amplitude of systolic Ca
2+
rises.
ANGES: reconstructing ANcestral GEnomeS maps
Authors: Jones Bradley R. , Rajaraman Ashok , Tannier Eric , Chauve Cedric
Published: July 2012

Summary: ANGES is a suite of Python programs that allows reconstructing ancestral genome maps from the comparison of the organization of extant-related genomes. ANGES can reconstruct ancestral genome maps for multichromosomal linear genomes and unichromosomal circular genomes. It implements methods inspired from techniques developed to compute physical maps of extant genomes. Examples of cereal, amniote, yeast or bacteria ancestral genomes are provided, computed with ANGES.

Availability: ANGES is freely available for download at http://paleogenomics.irmacs.sfu.ca/ANGES/. Documentation and examples are available together with the package.

Contact:  cedric.chauve@sfu.ca
GenAlEx 6.5: genetic analysis in Excel. Population genetic software for teaching and research—an update
Authors: Peakall Rod , Smouse Peter E.
Published: July 2012

Summary: GenAlEx: Genetic Analysis in Excel is a cross-platform package for population genetic analyses that runs within Microsoft Excel. GenAlEx offers analysis of diploid codominant, haploid and binary genetic loci and DNA sequences. Both frequency-based (F-statistics, heterozygosity, HWE, population assignment, relatedness) and distance-based (AMOVA, PCoA, Mantel tests, multivariate spatial autocorrelation) analyses are provided. New features include calculation of new estimators of population structure: G′ST, G′′ST, Jost’s Dest and F′ST through AMOVA, Shannon Information analysis, linkage disequilibrium analysis for biallelic data and novel heterogeneity tests for spatial autocorrelation analysis. Export to more than 30 other data formats is provided. Teaching tutorials and expanded step-by-step output options are included. The comprehensive guide has been fully revised.

Availability and implementation: GenAlEx is written in VBA and provided as a Microsoft Excel Add-in (compatible with Excel 2003, 2007, 2010 on PC; Excel 2004, 2011 on Macintosh). GenAlEx, and supporting documentation and tutorials are freely available at: http://biology.anu.edu.au/GenAlEx.

Contact:  rod.peakall@anu.edu.au
Pseudenhygromyxa salsuginis gen. nov., sp. nov., a myxobacterium isolated from an estuarine marsh
Authors: Iizuka Takashi , Jojima Yasuko , Hayakawa Atsushi , Fujii Takayoshi , Yamanaka Shigeru , Fudou Ryosuke
Published: July 2012

A myxobacterial strain, designated SYR-2T, was obtained from a mud sample from an estuarine marsh alongside the Yoshino River, Shikoku, Japan. It had rod-shaped vegetative cells and formed bacteriolytic enlarging colonies or so-called ‘swarms’ in the agar media. Fruiting-body-like globular to polyhedral cell aggregates and myxospore-like spherical to ellipsoidal cells within them were observed. Those features coincided with the general characteristics of myxobacteria. The strain was mesophilic and strictly aerobic. Growth of SYR-2Twas observed at 18–40 °C (optimum, 30–35 °C), pH 5.5–8.3 (optimum, pH 7.0–7.5) and with 0.0–2.5 % (w/v) NaCl (optimum, 0.2–1.0 %). Both Mg2+and Ca2+were essential cations for the growth. The predominant fatty acids were iso-C15 : 0(43.8 %), iso-C17 : 0(22.4 %) and iso-C16 : 0(9.6 %). A C20 : 4fatty acid [arachidonic acid (4.3 %)], iso-C19 : 0(1.5 %) and anteiso-acids [ai-C15 : 0(0.5 %), ai-C17 : 0(0.3 %)] were also detected. The G+C content of the DNA was 69.7 mol%. The strain contained menaquinone-7 (MK-7) as the major respiratory quinone. Phylogenetic analyses based on 16S rRNA gene sequences showed that strain SYR-2Tbelonged to the suborderNannocystineae, orderMyxococcalesin the classDeltaproteobacteria, and the strain was most closely related to two type strains of marine myxobacteria,Enhygromyxa salinaSHK-1TandPlesiocystis pacificaSIR-1T, with 96.5 % and 96.0 % similarities, respectively. These characteristics determined in this polyphasic study suggested that strain SYR-2Trepresents a novel species in a new genus of myxobacteria. The namePseudenhygromyxa salsuginisgen. nov., sp. nov. is proposed to accommodate this isolate, and the type strain ofPseudenhygromyxa salsuginisis SYR-2T( = NBRC 104351T = DSM 21377T).
Humitalea rosea gen. nov., sp. nov., an aerobic bacteriochlorophyll-containing bacterium of the family

Acetobacteraceae

isolated from soil
Authors: Margesin Rosa , Zhang De-Chao
Published: July 2012

A Gram-staining-negative, pale-pink-pigmented, non-motile, obligately aerobic and rod-shaped bacterium, designated strain W37T, was isolated from soil and subjected to a taxonomic investigation using a polyphasic approach. The strain grew at 1–30 °C, oxidized thiosulfate and accumulated polyhydroxyalkanoates. Photosynthetic pigments were represented by bacteriochlorophyll a and carotenoids. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain W37T was most closely related to members of the genera

Roseococcus

and

Rubritepida

(with sequence similarities of <92.8 %) but formed a distinct lineage in the family

Acetobacteraceae

. The polar lipid profile comprised diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine, three unidentified aminolipids and one other unidentified lipid. The predominant cellular fatty acids were C18 : 1ω7c and summed feature 3 (C16 : 1ω7c and/or iso-C15 : 0 2-OH). The DNA G+C content of strain W37T was 68.2 mol%. On the basis of phenotypic characteristics and phylogenetic analysis, strain W37T represents a novel species of a new genus in the family

Acetobacteraceae

, for which the name Humitalea rosea gen. nov., sp. nov. is proposed. The type strain of the type species is W37T ( = CIP 110261T = LMG 26243T).
Noise–mean relationship in mutated promoters
Authors: Hornung Gil , Bar-Ziv Raz , Rosin Dalia , Tokuriki Nobuhiko , Tawfik Dan S. , Oren Moshe , Barkai Naama
Published: July 2012

Gene expression depends on the frequency of transcription events (burst frequency) and on the number of mRNA molecules made per event (burst size). Both processes are encoded in promoter sequence, yet their dependence on mutations is poorly understood. Theory suggests that burst size and frequency can be distinguished by monitoring the stochastic variation (noise) in gene expression: Increasing burst size will increase mean expression without changing noise, while increasing burst frequency will increase mean expression and decrease noise. To reveal principles by which promoter sequence regulates burst size and frequency, we randomly mutated 22 yeast promoters chosen to span a range of expression and noise levels, generating libraries of hundreds of sequence variants. In each library, mean expression (m) and noise (coefficient of variation, η) varied together, defining a scaling curve: η2 = b/m+ηext2. This relation is expected if sequence mutations modulate burst frequency primarily. The estimated burst size (b) differed between promoters, being higher in promoter containing a TATA box and lacking a nucleosome-free region. The rare variants that significantly decreased b were explained by mutations in TATA, or by an insertion of an out-of-frame translation start site. The decrease in burst size due to mutations in TATA was promoter-dependent, but independent of other mutations. These TATA box mutations also modulated the responsiveness of gene expression to changing conditions. Our results suggest that burst size is a promoter-specific property that is relatively robust to sequence mutations but is strongly dependent on the interaction between the TATA box and promoter nucleosomes.
A Structural Basis for the Biosynthesis of the Major Chlorogenic Acids Found in Coffee
Authors: Lallemand Laura A. , Zubieta Chloe , Lee Soon Goo , Wang Yechun , Acajjaoui Samira , Timmins Joanna , McSweeney Sean , Jez Joseph M. , McCarthy James G. , McCarthy Andrew A.
Published: July 2012

Chlorogenic acids (CGAs) are a group of phenolic secondary metabolites produced by certain plant species and an important component of coffee (Coffea spp.). The CGAs have been implicated in biotic and abiotic stress responses, while the related shikimate esters are key intermediates for lignin biosynthesis. Here, two hydroxycinnamoyl-coenzyme A shikimate/quinate hydroxycinnamoyl transferases (HCT/HQT) from coffee were biochemically characterized. We show, to our knowledge for the first time, that in vitro, HCT is capable of synthesizing the 3,5-O-dicaffeoylquinic acid diester, a major constituent of the immature coffee grain. In order to further understand the substrate specificity and catalytic mechanism of the HCT/HQT, we performed structural and mutagenesis studies of HCT. The three-dimensional structure of a native HCT and a proteolytically stable lysine mutant enabled the identification of important residues involved in substrate specificity and catalysis. Site-directed mutagenesis confirmed the role of residues leucine-400 and phenylalanine-402 in substrate specificity and of histidine-153 and the valine-31 to proline-37 loop in catalysis. In addition, the histidine-154-asparagine mutant was observed to produce 4-fold more dichlorogenic acids compared with the native protein. These data provide, to our knowledge, the first structural characterization of a HCT and, in conjunction with the biochemical and mutagenesis studies presented here, delineate the underlying molecular-level determinants for substrate specificity and catalysis. This work has potential applications in fine-tuning the levels of shikimate and quinate esters (CGAs including dichlorogenic acids) in different plant species in order to generate reduced or elevated levels of the desired target compounds.
The Agricultural Resource Management Survey
Authors: Kuethe Todd , Morehart Mitch
Published: July 2012

Purpose

The purpose of this article is to offer an introduction of the Agricultural Resource Management Survey (ARMS) for applied research in agricultural finance and farm management.

Design/methodology/approach

This article provides a brief overview of the history, design, use, and accessibility of the ARMS in government reporting and applied research.

Findings

The ARMS provides a number of unique advantages for addressing critical issues of the agricultural sector.

Originality/value

The paper provides an access point for researchers who are unfamiliar with the basic features of ARMS.
Accounting for complex entities: implications for ARMS
Authors: Moss Charles B. , Klinefelter Danny A. , Gunderson Michael A.
Published: July 2012

Purpose

The purpose of this research is to examine the effect of accounting for complex organizational forms on data collection with the Agricultural Resource Management Survey (ARMS).

Design/methodology/approach

This research reviews the literature from accounting theory along with the goals of data collection for policy analysis to draw conclusions about the applicability of accounting pronouncements.

Findings

Historically, the financial data collected in ARMS were based on financial accounting standards which were adequate for most purposes. However, this study develops the fact that many of these financial accounting standards were created to provide information for equity market transactions. The complexities of accounting for consolidations will provide valuable information, but implementing these standards will require accounting sophistication that is not prevalent in agriculture.

Originality/value

By drawing accounting theory together with the targeted use of data, this study offers guidelines to improve the data quality for a growing complex US agriculture.
Balance sheet and income statement issues in ARMS
Authors: Ellinger Paul N. , Ahrendsen Bruce L. , Moss Charles B.
Published: July 2012

Purpose

The purpose of this research is to analyze possible implications of the economic measures presented in the balance sheet and income statement of the farm firm.

Design/methodology/approach

Accounting principles and the users of accounting information are studied. From a review of the Agricultural Resource Management Survey (ARMS) questionnaire, several items are identified that limit ARMS information from fully measuring economic and financial conditions.

Findings

ARMS limitations include issues related to asset valuation, income and expense recognition, and extraordinary income reporting. In particular, data limitations on deferred taxes associated with market values exceeding cost, capital leases, prepaid rents, accrued items, Section 179 and accelerated depreciation methods, and extraordinary items may result in understatement of leverage, overstatement of liquidity, and under reporting of year‐to‐year farm income variability measures.

Originality/value

By identifying these limitations, changes can be made that may result in improved measures of farm financial condition and farm household well‐being.
US farm debt: the role of ARMS
Authors: Briggeman Brian C. , Koenig Steven R. , Moss Charles B.
Published: July 2012

Purpose

To identify periods of severe stress, and potentially take action to avoid or dampen their negative effects, lenders and policymakers need accurate and reliable data on US farm debt supply and credit needs. The purpose of this paper is to assess the current availability of information on US farm debt as well as its accuracy.

Design/methodology/approach

A review of the farm debt information and survey methodology of the Agricultural Resource Management Survey (ARMS).

Findings

This manuscript examines several potential issues involving the debt and lender data within ARMS. First, the empirical results indicate that there is an informational break in ARMS beginning in 2000. Second, the paper presents evidence that the overall level of debt reported by USDA is not consistent with information reported by lenders for other regulatory sources. Finally, the paper proposes a modification of the debt question to improve the data collection.

Originality/value

The paper offers an external review of farm debt information in ARMS.
Using sector financial statements and ARMS data to prepare statements of owner equity and cash flows for the agricultural sector
Authors: Barnard Freddie L. , Nordquist Dale W.
Published: July 2012

Purpose

The purpose of this paper is to discuss the feasibility of preparing a statement of owner equity (SOE) and statement of cash flows (SOCF) for the agricultural sector. Also, the use of the Agricultural Resource Management Survey (ARMS) to collect data needed to supplement the US farm sector accounts to prepare a sector SOE and SOCF is discussed.

Design/methodology/approach

An SOE and SOCF for an individual producer was used to provide an example format for preparing an SOE and SOCF for the agricultural sector and to identify the data needed from the ARMS survey to supplement farm sector accounts.

Findings

The format and data needed to prepare a sector SOE and SOCF were identified and the feasibility of the collection of that data using current ERS/USDA survey collection methods would provide the data needed to prepare the statements. However, the use of two independent data collection authorities to collect the data would result in an agricultural sector SOE and SOCF that would not reconcile.

Originality/value

The paper initiates a dialog of possible alternatives available to the ERS/USDA and researchers concerning data needed and data sources available to prepare an agricultural sector SOE and SOCF, as well as the shortfalls and inaccuracies that would result.
Sustainability and local food procurement: a case study of Finnish public catering
Authors: Lehtinen Ulla
Published: July 2012

Purpose

The aim of the paper is to present how sustainability as a concept supports the use of locally‐sourced food in public catering, and the issues that arise from that policy objective and their implications for suppliers and purchasers.

Design/methodology/approach

First, the paper explains the characteristics of local food chains and the concept of sustainability based on a literature review. It then outlines the stages of the food procurement process in public food catering in Finland, focussing on the delivery of potatoes from a local producer to a public caterer providing school meals. The case study identifies the dimensions of sustainability.

Findings

First, the criteria defining sustainability remain unclear. Second, to overcome the cost disadvantages brought about by its small‐scale production and high delivery costs, locally‐sourced food should add some extra value. Short food supply chains have advantages over long ones, however, they are not sustainableper se.

Research limitations/implications

The research is descriptive in nature and rests on action research implemented during 2004‐2007. The study does not provide any quantitative analysis nor can it be statistically generalised.

Practical implications

Measuring the impact of sustainability in a public tendering process remains challenging, as an unambiguous definition of sustainability criteria is lacking. Further, sustainable procurement practices would improve collaborative relationships.

Originality/value

This paper complements the current discussion on sustainability and local food. Provision of free school meals is now a rare phenomenon, and has recently stirred widespread interest. Finland's continuing commitment to providing free school meals thus provides a very specific context in which to study the problems of food sourcing in the public sector.
Sensory evaluation and consumer perception of some commercial green table olives
Authors: Yilmaz Emin , Aydeniz Buket
Published: July 2012

Purpose

The objective of this study is to evaluate the physico‐chemical and sensorial characteristics of some commercial green table olives. Also, it seeks to elaborate the sensorial background of consumer preferences of different green table olives.

Design/methodology/approach

Four green table olive samples (Çelebi, Domat, Kaba, and Ayvalık) commonly consumed in Turkey were chosen and collected from a local producer. Dimensional measures, salt content, pH value, oil content, titrable acidity, L value, a* value, b* value and texture of samples were assessed by the AOAC methods. A panel described and measured the appearance (greenness, yellowness, globeness), aroma (fresh olive, vinegary, soapy, musty), flavour (sour, salty, bitter, hay, oily) and texture properties (firmness, flesh/stone adherence, fibrousness, watery). In addition, 50 consumers evaluated hedonic values.

Findings

The salt content, pH value, oil content, titrable acidity, L value, a* value, b* value and texture of samples were found to following values 2.91‐5.46 percent, 2.80‐3.97, 4.67‐18.71 percent, 0.59‐1.40 percent, 49.96‐69.56, 1.35‐17.91, 19.57‐45.47 and 434.1‐895.7 g. Although prepared with the same technique, many properties of the olives were found different. This difference affected consumer preference and buying intentions as well.

Research limitations/implications

The paper provides scientific data for researchers to design similar sensory descriptive analyses for different table olive samples.

Originality/value

The paper is helpful both to consumers and traders to determine the proximate and sensory attributes of commercial green olive samples.
Organic food consumers: what do we really know about them?
Authors: Dimitri Carolyn , Dettmann Rachael L.
Published: July 2012

Purpose

The organic trade literature in the USA makes strong claims about the relationship between income, ethnicity, and other factors and the likelihood of purchasing organic food products. However, previous economic research focusing on the socio‐economic characteristics of organic food consumers yields mixed findings. One explanation for the literature's inconsistent findings is that most studies rely on one specific product or one region of the country, or base their analysis on data collected from in‐store surveys. Another shortcoming in the existing literature is the failure to account for how access to organic food influences the likelihood of buying organic food. This paper's goal is to identify what is known, as well as what is not known, about consumers of organic food.

Design/methodology/approach

The paper extends the literature through the combination of a novel approach and unique dataset of US consumers, and addresses the relationship between demographic traits and the likelihood of buying organic food. The dataset consists of primary data recording all purchases of food as well as household demographic data, such as income, education, gender, and ethnicity, over a one‐year period for 44,000 households. The study uses different discrete choice models and multiple product categories to explore the likelihood of buying organic food from many angles, in order to assess the robustness of the statistical relationship between income, education, ethnicity, and other factors on the likelihood of buying organic food, as well as the frequency of buying organic food.

Findings

The results indicate that education has a strong effect on the likelihood of buying organic products, and that the impact of marital status, income, and access to organic are consistent across models. The findings also suggest that further research on the links between ethnicity and consumption of organic food is necessary.

Research limitations/implications

One possible drawback to this dataset is that older, urban households are overrepresented, in comparison to the entire USA.

Practical implications

These findings will appeal to those interested in consumer behavior in addition to those interested in organic food consumption, from both the research and trade perspectives. The research indicates that access to organic food is an important determinant of the likelihood of a household buying organic food, the industry in the USA can expand sales by increasing consumer access to organic food.

Originality/value

This paper's unique contribution is the exploration of the robustness of the impact of different factors on the likelihood of buying organic food. The inclusion of access to organic food is also new to the literature, and as expected, households with greater access to organic food are more likely to purchase organic food.
Is social responsibility driven by industry or firm‐specific factors?
Authors: Moura‐Leite Rosamaria C. , Padgett Robert C. , Galan Jose I.
Published: July 2012

Purpose

This study aims to revisit the relative importance of industry and firm level effects on corporate social responsibility (CSR), with the objective of clarifying their diverse effects on CSR.

Design/methodology/approach

The authors suggest that CSR is a shared strategic asset based on insights from the industrial organization and institutional schools, taking into account that there are determinants of CSR that may be operating inside the corporation according to the resource‐based view. They employ a variance components method and a sample compiled of 495 US firms from 19 industries using five‐year periods.

Findings

The study indicates that firms retain considerable self‐determinism regarding their CSR trajectories, but the latter also represent a shared strategic asset. Thus, these results combined imply that CSR needs to be examined on both levels simultaneously.

Practical implications

The results of this study can provide non‐governmental organizations and governmental and regulatory institutions with an indicator that explains the performance variation levels of each dimension of CSR, and can help improve tools designed to promote it. Furthermore, the authors' research provides managers with evidence of CSR variability among CSR dimensions that could help in strategic decision‐making. In addition this research can provide assistance and give perspective regarding selection criteria for investment portfolios in responsible investment funds.

Originality/value

The industry effect is an important factor to consider in CSR intensity. The variation in firm and industry effects on CSR strategies has not been extensively studied; hence, explaining the sources of performance differences regarding industry and firm factors is a key theoretical and empirical issue in the field of management.
Perception of entrepreneurial opportunity: a general framework
Authors: Renko Maija , Shrader Rodney C. , Simon Mark
Published: July 2012

Purpose

Previous research has predominantly approached the concept of entrepreneurial opportunities from either one of two perspectives: opportunities exist as objective phenomena in the environment waiting to be discovered by alert entrepreneurs, or opportunities are subjectively perceived and even created by individual entrepreneurs. This paper aims to put forward a framework of opportunity perception which demonstrates that all entrepreneurial opportunities possess both objective and subjective qualities, thus helping reconcile both perspectives.

Design/methodology/approach

A conceptual framework is developed, based on previous literature and insights from entrepreneurship, economics, psychology and related disciplines.

Findings

Various perspectives presented in previous research can be combined into a coherent framework that summarizes the components of entrepreneurial opportunity perception. Testable propositions are provided for future research.

Originality/value

The authors show that elements of both subjective perception and objective market conditions contribute to recognized entrepreneurial opportunities. Also, they show that while the perception and pursuit of opportunity is fundamentally idiosyncratic to each entrepreneur, the success of an entrepreneurial endeavor is constrained by the objective conditions of opportunity.
Characterizing disagreement and inconsistency in experts' judgments in the analytic hierarchy process
Authors: Lin Shi‐Woei , Lu Ming‐Tsang
Published: July 2012

Purpose

Methods and techniques of aggregating preferences or priorities in the analytic hierarchy process (AHP) usually ignore variation or dispersion among experts and are vulnerable to extreme values (generated by particular viewpoints or experts trying to distort the final ranking). The purpose of this paper is to propose a modelling approach and a graphical representation to characterize inconsistency and disagreement in the group decision making in the AHP.

Design/methodology/approach

The authors apply a regression approach for estimating the decision weights of the AHP using linear mixed models (LMM). They also test the linear mixed model and the multi‐dimensional scaling graphical display using a case of strategic performance management in education.

Findings

In addition to determining the weight vectors, this model also allows the authors to decompose the variation or uncertainty in experts' judgment. Well‐known statistical theories can estimate and rigorously test disagreement among experts, the residual uncertainty due to rounding errors in AHP scale, and the inconsistency within individual experts' judgments. Other than characterizing different sources of uncertainty, this model allows the authors to rigorously test other factors that might significantly affect weight assessments.

Originality/value

This study provides a model to better characterize different sources of uncertainty. This approach can improve decision quality by allowing analysts to view the aggregated judgments in a proper context and pinpoint the uncertain component that significantly affects decisions.
Delphi method applied to horticultural cooperatives
Authors: Campos‐Climent Vanessa , Apetrei Andreea , Chaves‐Ávila Rafael
Published: July 2012

Purpose

Agricultural cooperatives have been able to become a strong and consolidated organizational form, although the new challenges of globalization and trade liberalization require changes in the strategic approach. The requirements of the distribution companies, consumers and government about the concentration of demand, traceability, food safety and respect for the environment had led to a thorough reorganization of agricultural food systems. So it is necessary to undertake a strategic review of horticultural cooperatives in order to conduct a strategic assessment and hence identify the strategic actions to be followed in the coming years. This paper seeks to address these issues.

Design/methodology/approach

An empirical study has been carried out during the first half of 2011 consisting in the application of the Delphi method and sending a questionnaire to experts whose purpose was to gain a view of the strategic situation of horticultural cooperatives in Spain. The Delphi method is a projection technique of the qualitative and subjective type which is appropriate for studies where there is little information on the subject to be analysed, and also for exploratory studies, as it is the case study of examining the role of agricultural cooperatives in coming out of the crisis of Mediterranean agriculture.

Findings

The performed Delphi analysis revealed that Mediterranean agriculture suffers from a severe crisis for which the solutions are hard to find, although the existence of the agricultural cooperatives and certain specific forms of performance and financing can partly improve the described situation. The application of the SWOT analysis based on the opinions of the experts provided sufficient detailed insights of the actual situation of the cooperatives. Thus, from the Delphi SWOT applied to Mediterranean agriculture and agricultural cooperatives, the authors can make some important assessments which are included in their paper.

Originality/value

It is a forward‐looking analysis that tries to give measures to the sector, but measures that come from the sector, in order to face the Mediterranean agriculture crisis.