bluuebunny/crossref_metadata_2025 huggingface dataset:
Pegaso Peru: An Overdue Project (A) and (B)
Authors: Tsuja Peter Yamakawa , Rees Gareth H , Tuesta Julio Quispe , Marengo José Carrión , Escobar Kenny Luis , Guevara Aquije Julio
Published: March 2014

Brunella Noli, General Manager of a Peruvian consulting firm (Pegaso Peru), reviews the history of a troubled IT project for client Casa Master Center (CMC). The project is 11 months overdue, and CMC is an increasingly unhappy client. Noli's review, which starts with the sale and recounts the project's scope, contract and implementation, uncovers a series of problems. Noli seeks to resolve these issues without incurring additional costs. She worries that the relationship with the client is rapidly deteriorating and she fears that this will damage Pegaso's reputation. A second one-page Case B recounts what happened next. This case is based on actual events in real organizations. The identities of the parties involved have been changed, along with other key information, to preserve anonymity.
Calculation of anharmonic couplings and THz linewidths in crystalline PETN
Authors: Pereverzev Andrey , Sewell Thomas D. , Thompson Donald L.
Published: March 2014

We have developed a method for calculating the cubic anharmonic couplings in molecular crystals for normal modes with the zero wave vector in the framework of classical mechanics, and have applied it, combined with perturbation theory, to obtain the linewidths of all infrared absorption lines of crystalline pentaerythritol tetranitrate in the terahertz region (<100 cm−1). Contributions of the up- and down-conversion processes to the total linewidth were calculated. The computed linewidths are in qualitative agreement with experimental data and the results of molecular dynamics simulations. Quantum corrections to the linewidths in the terahertz region are shown to be negligible.
Effective electron displacements: A tool for time-dependent density functional theory computational spectroscopy
Authors: Guido Ciro A. , Cortona Pietro , Adamo Carlo
Published: March 2014

We extend our previous definition of the metric Δr for electronic excitations in the framework of the time-dependent density functional theory [C. A. Guido, P. Cortona, B. Mennucci, and C. Adamo, J. Chem. Theory Comput. 9, 3118 (2013)], by including a measure of the difference of electronic position variances in passing from occupied to virtual orbitals. This new definition, called Γ, permits applications in those situations where the Δr-index is not helpful: transitions in centrosymmetric systems and Rydberg excitations. The Γ-metric is then extended by using the Natural Transition Orbitals, thus providing an intuitive picture of how locally the electron density changes during the electronic transitions. Furthermore, the Γ values give insight about the functional performances in reproducing different type of transitions, and allow one to define a “confidence radius” for GGA and hybrid functionals.
Multi-time Schrödinger equations cannot contain interaction potentials
Authors: Petrat Sören , Tumulka Roderich
Published: March 2014

Multi-time wave functions are wave functions that have a time variable for every particle, such as \documentclass[12pt]{minimal}\begin{document}$\phi (t_1,{\bm x}_1,\ldots ,t_N,{\bm x}_N)$\end{document}ϕ(t1,x1,...,tN,xN). They arise as a relativistic analog of the wave functions of quantum mechanics but can be applied also in quantum field theory. The evolution of a wave function with N time variables is governed by N Schrödinger equations, one for each time variable. These Schrödinger equations can be inconsistent with each other, i.e., they can fail to possess a joint solution for every initial condition; in fact, the N Hamiltonians need to satisfy a certain commutator condition in order to be consistent. While this condition is automatically satisfied for non-interacting particles, it is a challenge to set up consistent multi-time equations with interaction. We prove for a wide class of multi-time Schrödinger equations that the presence of interaction potentials (given by multiplication operators) leads to inconsistency. We conclude that interaction has to be implemented instead by creation and annihilation of particles, which, in fact, can be done consistently [S. Petrat and R. Tumulka, “Multi-time wave functions for quantum field theory,” Ann. Physics (to be published)]. We also prove the following result: When a cut-off length δ > 0 is introduced (in the sense that the multi-time wave function is defined only on a certain set of spacelike configurations, thereby breaking Lorentz invariance), then the multi-time Schrödinger equations with interaction potentials of range δ are consistent; however, in the desired limit δ → 0 of removing the cut-off, the resulting multi-time equations are interaction-free, which supports the conclusion expressed in the title.
A parallel alignment device with dynamic force compensation for nanoimprint lithography
Authors: Chen Weihai , Du Chong , Wu Yunjie , Chen Wenjie , Yuan Mei
Published: March 2014

Nanoimprint lithography is a nano/micro patterning technology to fabricate functional devices by pressing a template with predefined structures on a substrate. Uniformity of the force distribution between the contacting surfaces should be ensured to produce features with high fidelity. In this paper, a parallel alignment device with the abilities of dynamic force distribution control is developed. By adopting a spherical air bearing held with a 5-degree-of-freedom flexure-based stage, wedge errors between the template and the substrate can be eliminated passively without friction when an imprint force is applied. Since the vertical imprint force is mainly supported by the spherical air bearing, the device is very suitable for high force applications, without causing damage to the delicate compliant stage or precision degradation. Besides, the force distribution of the imprint process is measured, based on which dynamic force compensation is performed by actuating the compliant stage actively. Five-hundred-nm-period grating structures are transferred successfully with the device and proofs effectiveness of the device.
Antiferromagnetic interlayer exchange coupling in epitaxial Fe/MgO/Fe trilayers with MgO barriers as thin as single monolayers
Authors: Kozioł-Rachwał A. , Ślęzak T. , Ślęzak M. , Matlak K. , Młyńczak E. , Spiridis N. , Korecki J.
Published: March 2014

Comparative studies of the magnetic properties of epitaxial Fe/MgO/Fe trilayers, which were directly grown on an MgO(001) crystal and a homoepitaxial MgO buffer layer, were performed to examine the interlayer exchange coupling as a function of the MgO spacer thickness. Measurements of the magneto-optic Kerr effect at room temperature demonstrated that there was a strong antiferromagnetic coupling (AFC) between the Fe layers, which was mediated by the insulating MgO barrier. A measurable AFC was found in a range of MgO thickness (dMgO) from a single monolayer (2 Å) to 6 Å, which had a maximum strength of −1.15 ergs/cm2 at dMgO = 2.7 Å for the Fe/MgO/Fe trilayers that were prepared on the buffered sample and was notably weaker for the trilayers that were prepared directly on the MgO(001).
Micellar morphological transformations for a series of linear diblock model surfactants
Authors: Daful Asfaw Gezae , Mackie Allan D.
Published: March 2014

The concentration induced shape transitions of linear model surfactants, HxTy, on a lattice have been studied using Monte Carlo simulation. It has been found that a sphere to cylinder shape transition is generally found on shortening the hydrophilic part of the surfactant and anticipates an eventual phase transition. Asymmetric surfactants with longer heads than tails (x > y) prefer to form only spherical micelles independent of total surfactant concentration while asymmetric surfactants with longer tails than heads (x < y) form spherical micelles at lower concentration and undergo a shape transition to cylindrical micelles on increasing the total concentration. Finally, in the case of symmetric surfactants with x = y, only the shortest surfactants H1T1 and H2T2 undergo a sphere to cylinder shape transition on increasing surfactant concentration. Longer symmetric surfactants are always found to prefer to form spherical micelles.
Maximum power point tracking of partial shaded photovoltaic array using an evolutionary algorithm: A particle swarm optimization technique
Authors: Seyedmahmoudian Mohammadmehdi , Mekhilef Saad , Rahmani Rasoul , Yusof Rubiyah , Asghar Shojaei Ali
Published: March 2014

Partial shading is one of the unavoidable complications in the field of solar power generation. Although the most common approach in increasing a photovoltaic (PV) array's efficiency has always been to introduce a bypass diode to the said array, this poses another problem in the form of multi-peaks curves whenever the modules are partially shaded. To further complicate matters, most conventional Maximum Power Point Tracking methods develop errors under certain circumstances (for example, they detect the local Maximum Power Point (MPP) instead of the global MPP) and reduce the efficiency of PV systems even further. Presently, much research has been undertaken to improve upon them. This study aims to employ an evolutionary algorithm technique, also known as particle swarm optimization, in MPP detection.
Effect of Co on the thermal stability and magnetic properties of AlNiCo 8 alloys
Authors: Liu Tao , Li Wei , Zhu Minggang , Guo Zhaohui , Li Yanfeng
Published: March 2014

The magnetic properties, microstructure, and reversible temperature coefficient of magnetic flux of Alnico 8 alloys with the different Co and Ti have been investigated in this paper. The Alnico alloys containing 34, 36, 38, and 40 mass percent cobalt were fabricated by the conventional casting method including thermomagnetic treatment. The transmission electron microscopy (TEM) testing shows that there are more α1 phases particles with the diameter of less than 10 nm appearing in the matrix with the increasing of the content of Co and Ti. The thermal stability of Alnico 8 alloys deteriorates with the increasing of the content of Co and Ti, which are caused mainly by the decrease of the degree of particle alignment and particle perfection.
Current-based detection of nonlocal spin transport in graphene for spin-based logic applications
Authors: Wen Hua , Zhu Tiancong , Luo Yunqiu (Kelly) , Amamou Walid , Kawakami Roland K.
Published: March 2014

Graphene has been proposed for novel spintronic devices due to its robust and efficient spin transport properties at room temperature. Some of the most promising proposals require current-based readout for integration purposes, but the current-based detection of spin accumulation has not yet been developed. In this work, we demonstrate current-based detection of spin transport in graphene using a modified nonlocal geometry. By adding a variable shunt resistor in parallel to the nonlocal voltmeter, we are able to systematically cross over from the conventional voltage-based detection to current-based detection. As the shunt resistor is reduced, the output current from the spin accumulation increases as the shunt resistance drops below a characteristic value R*. We analyze this behavior using a one-dimensional drift-diffusion model, which accounts well for the observed behavior. These results provide the experimental and theoretical foundation for current-based detection of nonlocal spin transport.
Perfect alignment and preferential orientation of nitrogen-vacancy centers during chemical vapor deposition diamond growth on (111) surfaces
Authors: Michl Julia , Teraji Tokuyuki , Zaiser Sebastian , Jakobi Ingmar , Waldherr Gerald , Dolde Florian , Neumann Philipp , Doherty Marcus W. , Manson Neil B. , Isoya Junichi , Wrachtrup Jörg
Published: March 2014

Synthetic diamond production is a key to the development of quantum metrology and quantum information applications of diamond. The major quantum sensor and qubit candidate in diamond is the nitrogen-vacancy (NV) color center. This lattice defect comes in four different crystallographic orientations leading to an intrinsic inhomogeneity among NV centers, which is undesirable in some applications. Here, we report a microwave plasma-assisted chemical vapor deposition diamond growth technique on (111)-oriented substrates, which yields perfect alignment (94% ± 2%) of as-grown NV centers along a single crystallographic direction. In addition, clear evidence is found that the majority (74% ± 4%) of the aligned NV centers were formed by the nitrogen being first included in the (111) growth surface and then followed by the formation of a neighboring vacancy on top. The achieved homogeneity of the grown NV centers will tremendously benefit quantum information and metrology applications.
Influence of microstructure on soft magnetic properties of low coreloss and high Bs Fe85Si2B8P4Cu1 nanocrystalline alloy
Authors: Sharma Parmanand , Zhang Xin , Zhang Yan , Makino Akihiro
Published: March 2014

Microstructure and magnetic properties of high Bs Fe85Si2B8P4Cu1 nano-crystalline alloy were tailored. The Bs ∼ 1.85 T and low coercivity Hc ∼ 6 A/m were obtained by conventional annealing (i.e., one step) at a heating rate of ∼400 °C/min. While one step annealing process produces a fairly stable nanostructure, for short times at temperatures <425 °C, the nanostructure and concomitant magnetic properties of this alloy are shown to be tunable by two step annealing process. Nanocrystalline ribbons with grain size (D) ranging from ∼15 to 32 nm, Hc ∼ 6 to 140 A/m and core-loss at 1.5 T, 50 Hz ∼ 0.39 ∼ 5.0 W/kg were obtained. The Hc of Fe85Si2B8P4Cu1 alloy is shown to vary as D6, but a small deviation was noticed, which may be due to weak anisotropy.
Magnetic properties of single-phase MnBi grown from MnBi49 melt
Authors: Xiao X. F. , Si P. Z. , Feng H. , Ye Q. L. , Yu S. J. , Ge H. L. , Liu J. J.
Published: March 2014

The single-phase NiAs-type MnBi, embedded in Bi matrix, was grown from homogeneous MnBi49 melt at low temperatures to prevent the formation of Mn1.08Bi. An abrupt magnetization change was observed at ∼240 K. The origin of this change was ascribed to the movement of the Mn atoms between the regular sites and the interstitial sites in the MnBi lattices. The splitting of the x-ray photoelectron lines of MnBi indicates the presence of two binding states of Mn atoms, one of which was ascribed to interstitial Mn atoms. A large coercivity up to 1.79 T at 400 K was observed in the as-grown bulk isotropic MnBi alloys.
Electron-exchange effects on the charge capture process in degenerate quantum plasmas
Authors: Jung Young-Dae , Akbari-Moghanjoughi M.
Published: March 2014

The electron-exchange effects on the charge capture process are investigated in degenerate quantum plasmas. The Bohr-Lindhard formalism with the effective interaction potential is employed to obtain the charge capture radius, capture probability, and capture cross section as functions of the impact parameter, projectile energy, electron-exchange parameter, Fermi energy, and plasmon energy. The result shows that the electron-exchange effect enhances the charge capture radius and the charge capture cross section in semiconductor quantum plasmas. It is also found that the charge capture radius and charge capture cross section increases with an increase of the Fermi energy and, however, decreases with increasing plasmon energy. Additionally, it is found that the peak position of the charge capture cross section is receded from the collision center with an increase of the electron-exchange parameter.
Growth of crystalline Al2O3 via thermal atomic layer deposition: Nanomaterial phase stabilization
Authors: Prokes S. M. , Katz M. B. , Twigg M. E.
Published: March 2014

We report the growth of crystalline Al2O3 thin films deposited by thermal Atomic Layer Deposition (ALD) at 200 °C, which up to now has always resulted in the amorphous phase. The 5 nm thick films were deposited on Ga2O3, ZnO, and Si nanowire substrates 100 nm or less in diameter. The crystalline nature of the Al2O3 thin film coating was confirmed using Transmission Electron Microscopy (TEM), including high-resolution TEM lattice imaging, selected area diffraction, and energy filtered TEM. Al2O3 coatings on nanowires with diameters of 10 nm or less formed a fully crystalline phase, while those with diameters in the 20–25 nm range resulted in a partially crystalline coating, and those with diameters in excess of 50 nm were fully amorphous. We suggest that the amorphous Al2O3 phase becomes metastable with respect to a crystalline alumina polymorph, due to the nanometer size scale of the film/substrate combination. Since ALD Al2O3 films are widely used as protective barriers, dielectric layers, as well as potential coatings in energy materials, these findings may have important implications.
Atomistic modeling of bending properties of oxidized silicon nanowires
Authors: Ilinov Andrey , Kuronen Antti
Published: March 2014

In this work, we have modeled a three point bending test of monocrystalline Si nanowires using molecular dynamics simulations in order to investigate their elastic properties. Tested nanowires were about 30 nm in length and had diameters from 5 to 9 nm. To study the influence of a native oxide layer, nanowires were covered with a 1 nm thick silica layer. The bending force was applied by a carbon diamond half-sphere with a 5 nm diameter. The Si-O parametrization for the Tersoff potential was used to describe atomic interactions between Si and O atoms. In order to remove the indentation effect of the diamond half-sphere and to obtain a pure bending behavior, we have also performed a set of simulations with fixed bottoms of the nanowires. Our results show that the oxide layer reduces the nanowire stiffness when compared with a pure Si nanowire with the same number of silicon atoms—in spite of the fact that the oxidized nanowires had larger diameters.
Multilayer-structured gold/nanoporous gold composite for high performance linear actuation
Authors: Zhang Su-Min , Jin Hai-Jun
Published: March 2014

We report a strategy to increase the linear stroke of nanoporous gold (npg) electrochemical actuator, by incorporating solid and parallel gold layers into npg and form Au/npg multilayer composites. The actuation strokes in the direction perpendicular to layer planes are larger than the rule-of-mixture predictions and can be 20% greater than that of monolithic npg; meanwhile, the multilayer composites are stiffer than the npg monolith. Current study provides an approach to simultaneously increase the actuation strain, the effective stiffness, and mechanical stability of actuation material, and thus global performance of np solid actuator.
On-chip generation and guiding of quantum light from a site-controlled quantum dot
Authors: Jamil Ayesha , Skiba-Szymanska Joanna , Kalliakos Sokratis , Schwagmann Andre , Ward Martin B. , Brody Yarden , Ellis David J. P. , Farrer Ian , Griffiths Jonathan P. , Jones Geb A. C. , Ritchie David A. , Shields Andrew J.
Published: March 2014

We demonstrate the emission and routing of single photons along a semiconductor chip originating from carrier recombination in an actively positioned InAs quantum dot. Device–scale arrays of quantum dots are formed by a two–step regrowth process. We precisely locate the propagating region of a unidirectional photonic crystal waveguide with respect to the quantum dot nucleation site. Under pulsed optical excitation, the multiphoton emission probability from the waveguide's exit is 12% ± 5% before any background correction. Our results are a major step towards the deterministic integration of a quantum emitter with the waveguiding components of photonic quantum circuits.
Zinc-finger protein ZFP318 is essential for expression of IgD, the alternatively splicedIghproduct made by mature B lymphocytes
Authors: Enders Anselm , Short Alanna , Miosge Lisa A. , Bergmann Hannes , Sontani Yovina , Bertram Edward M. , Whittle Belinda , Balakishnan Bhavani , Yoshida Kaoru , Sjollema Geoff , Field Matthew A. , Andrews T. Daniel , Hagiwara Hiromi , Goodnow Christopher C.
Published: March 2014

Significance

Mammalian B lymphocytes make antibodies of five different heavy chain isotypes, IgM, IgD, IgG, IgE, and IgA. The different isotypes are produced at discrete stages in B-cell development from a single immunoglobulin heavy chain (Igh) gene, either by irreversible rearrangement of the gene to make IgG, IgE, or IgA or by alternative splicing of the RNA transcribed from theIghgene to coexpress IgM and IgD. Developmentally regulated trans-acting factors have been hypothesized to control IgM and IgD expression from largeIghRNAs, but these factors have remained elusive for several decades. Here, using a genome-wide mutation screen in mice, we identify an obscure gene,Zfp318, as encoding a specific and essential factor promoting IgD expression in mature B cells.
DMAP: differential methylation analysis package for RRBS and WGBS data
Authors: Stockwell Peter A. , Chatterjee Aniruddha , Rodger Euan J. , Morison Ian M.
Published: March 2014

Motivation: The rapid development of high-throughput sequencing technologies has enabled epigeneticists to quantify DNA methylation on a massive scale. Progressive increase in sequencing capacity present challenges in terms of processing analysis and the interpretation of the large amount of data; investigating differential methylation between genome-scale data from multiple samples highlights this challenge.

Results: We have developed a differential methylation analysis package (DMAP) to generate coverage-filtered reference methylomes and to identify differentially methylated regions across multiple samples from reduced representation bisulphite sequencing and whole genome bisulphite sequencing experiments. We introduce a novel fragment-based approach for investigating DNA methylation patterns for reduced representation bisulphite sequencing data. Further, DMAP provides the identity of gene and CpG features and distances to the differentially methylated regions in a format that is easily analyzed with limited bioinformatics knowledge.

Availability and implementation: The software has been implemented in C and has been written to ensure portability between different platforms. The source code and documentation is freely available (DMAP: as compressed TAR archive folder) from http://biochem.otago.ac.nz/research/databases-software/ . Two test datasets are also available for download from the Web site. Test dataset 1 contains reads from chromosome 1 of a patient and a control, which is used for comparative analysis in the current article. Test dataset 2 contains reads from a part of chromosome 21 of three disease and three control samples for testing the operation of DMAP, especially for the analysis of variance. Example commands for the analyses are included.

Contact:  peter.stockwell@otago.ac.nz or aniruddha.chatterjee@otago.ac.nz

Supplementary information:  Supplementary data are available at Bioinformatics online .
Estimating telomere length from whole genome sequence data
Authors: Ding Zhihao , Mangino Massimo , Aviv Abraham ,   UK10K Consortium, Spector Tim , Durbin Richard
Published: March 2014

Telomeres play a key role in replicative ageing and undergo age-dependent attrition in vivo. Here, we report a novel method, TelSeq, to measure average telomere length from whole genome or exome shotgun sequence data. In 260 leukocyte samples, we show that TelSeq results correlate with Southern blot measurements of the mean length of terminal restriction fragments (mTRFs) and display age-dependent attrition comparably well as mTRFs.
Inconsistent Regulators: Evidence from Banking
*
Authors: Agarwal Sumit , Lucca David , Seru Amit , Trebbi Francesco
Published: March 2014

We find that regulators can implement identical rules inconsistently due to differences in their institutional design and incentives, and this behavior may adversely impact the effectiveness with which regulation is implemented. We study supervisory decisions of U.S. banking regulators and exploit a legally determined rotation policy that assigns federal and state supervisors to the same bank at exogenously set time intervals. Comparing federal and state regulator supervisory ratings within the same bank, we find that federal regulators are systematically tougher, downgrading supervisory ratings almost twice as frequently as do state supervisors. State regulators counteract these downgrades to some degree by upgrading more frequently. Under federal regulators, banks report worse asset quality, higher regulatory capital ratios, and lower return on assets. Leniency of state regulators relative to their federal counterparts is related to costly outcomes, such as higher failure rates and lower repayment rates of government assistance funds. The discrepancy in regulator behavior is related to different weights given by regulators to local economic conditions and, to some extent, differences in regulatory resources. We find no support for regulator self-interest, which includes “revolving doors” as a reason for leniency of state regulators.
Regional Favoritism
*
Authors: Hodler Roland , Raschky Paul A.
Published: March 2014

We complement the literature on distributive politics by taking a systematic look at regional favoritism in a large and diverse sample of countries and by employing a broad measure that captures the aggregate distributive effect of many different policies. In particular, we use satellite data on nighttime light intensity and information about the birthplaces of the countries’ political leaders. In our panel of 38,427 subnational regions from 126 countries with yearly observations from 1992 to 2009, we find that subnational regions have more intense nighttime light when being the birth region of the current political leader. We argue that this finding provides evidence for regional favoritism. We explore the dynamics and the geographical extent of regional favoritism and show that regional favoritism is most prevalent in countries with weak political institutions and poorly educated citizens. Furthermore, foreign aid inflows and oil rents tend to fuel regional favoritism in weakly institutionalized countries, but not elsewhere.
Public Health Insurance, Labor Supply, and Employment Lock *
Authors: Garthwaite Craig , Gross Tal , Notowidigdo Matthew J.
Published: March 2014

We study the effect of public health insurance on labor supply by exploiting a large public health insurance disenrollment. In 2005, approximately 170,000 Tennessee residents abruptly lost Medicaid coverage. Using both across- and within-state variation in exposure to the disenrollment, we estimate large increases in labor supply, primarily along the extensive margin. The increased employment is concentrated among individuals working at least 20 hours a week and receiving private, employer-provided health insurance. We explore the dynamic effects of the disenrollment and find an immediate increase in job search behavior and a steady rise in both employment and health insurance coverage following the disenrollment. Our results are consistent with a significant degree of “employment lock”—workers who are employed primarily to secure private health insurance coverage.
International Trade and Institutional Change: Medieval Venice’s Response to Globalization*
Authors: Puga Diego , Trefler Daniel
Published: March 2014

International trade can have profound effects on domestic institutions. We examine this proposition in the context of medieval Venice circa 800–1600. Early on, the growth of long-distance trade enriched a broad group of merchants who used their newfound economic muscle to push for constraints on the executive, that is, for the end of a de facto hereditary Doge in 1032 and the establishment of a parliament in 1172. The merchants also pushed for remarkably modern innovations in contracting institutions that facilitated long-distance trade, for example, the colleganza. However, starting in 1297, a small group of particularly wealthy merchants blocked political and economic competition: they made parliamentary participation hereditary and erected barriers to participation in the most lucrative aspects of long-distance trade. Over the next two centuries this led to a fundamental societal shift away from political openness, economic competition, and social mobility and toward political closure, extreme inequality, and social stratification. We document this oligarchization using a unique database on the names of 8,178 parliamentarians and their families’ use of the colleganza in the periods immediately before and after 1297. We then link these families to 6,959 marriages during 1400–1599 to document the use of marriage alliances to monopolize the galley trade. Monopolization led to the rise of extreme inequality, with those who were powerful before 1297 emerging as the undisputed winners.
Regulators Involved inDickeya solaniVirulence, Genetic Conservation, and Functional Variability
Authors: Potrykus Marta , Golanowska Małgorzata , Hugouvieux-Cotte-Pattat Nicole , Lojkowska Ewa
Published: March 2014

Bacteria from the genus Dickeya (formerly Erwinia chrysanthemi) are plant pathogens causing severe diseases in many economically important crops. A majority of the strains responsible for potato disease in Europe belong to a newly identified Dickeya solani species. Although some ecological and epidemiological studies have been carried out, little is known about the regulation of D. solani virulence. The characterization of four D. solani strains indicates significant differences in their virulence on potato, although they are genetically similar based on genomic fingerprinting profiles. A phenotypic examination included an analysis of virulence on potato; growth rate in culture; motility; Fe3+chelation; and pectate lyase, cellulase, protease, biosurfactant, and blue pigment production. Mutants of four D. solani strains were constructed by inactivating the genes coding either for one of the main negative regulators of D. dadantii virulence (kdgR, pecS, and pecT) or for the synthesis and perception of signaling molecules (expI and expR). Analysis of these mutants indicated that PecS, PecT, and KdgR play a similar role in both species, repressing, to different degrees, the synthesis of virulence factors. The thermoregulator PecT seems to be a major regulator of D. solani virulence. This work also reveals the role of quorum sensing mediated by ExpI and ExpR in D. solani virulence on potato.
The Role of Safety Culture in Influencing Provider Perceptions of Patient Safety
Authors: Bishop Andrea C. , Boyle Todd A.
Published: March 2014

Objectives

To determine how provider perceptions of safety culture influence their involvement in patient safety practices.

Methods

Health-care providers were surveyed in 2 tertiary hospitals located in Atlantic Canada, composed of 4 units in total. The partial least squares (PLS) approach to structural equation modeling was used to analyze the data. Latent variables provider PLS model encompassed the hypothesized relationships between provider characteristics, safety culture, perceptions of patient safety practices, and actual performance of patient safety practices, using the Health Belief Model (HBM) as a guide. Data analysis was conducted using SmartPLS.

Results

A total of 113 health-care providers completed a survey out of an eligible 318, representing a response rate of 35.5%. The final PLS model showed acceptable internal consistency with all four latent variables having a composite reliability score above the recommended 0.70 cutoff value (safety culture = 0.86, threat = 0.76, expectations = 0.83, PS practices = 0.75). Discriminant validity was established, and all path coefficients were found to be significant at the α = 0.05 level using nonparametric bootstrapping. The survey results show that safety culture accounted for 34% of the variance in perceptions of threat and 42% of the variance in expectations.

Conclusions

This research supports the role that safety culture plays in the promotion and maintenance of patient safety activities for health-care providers. As such, it is recommended that the introduction of new patient safety strategies follow a thorough exploration of an organization’s safety culture.
Adjunctive rifampicin may improve outcomes in Staphylococcus aureus bacteraemia: a systematic review
Authors: Russell Clark D. , Lawson McLean Aaron , Saunders Christopher , Laurenson Ian F.
Published: March 2014

Staphylococcus aureus bacteraemia (SAB) is associated with substantial morbidity and mortality. By surviving within leukocytes, S. aureus can evade both immunological defences and antimicrobial drugs, thus facilitating haematogenous dissemination. We performed a systematic review to determine whether antimicrobials with intracellular activity improve outcomes in SAB when used as an adjunct to β-lactam or glycopeptide monotherapy. The Pubmed/MEDLINE, Embase and Cochrane databases were systematically searched for eligible studies that reported on the use of first-line antimicrobials plus a single additional antimicrobial of interest in patients with SAB (any cause). Six relevant studies were identified, all reporting on rifampicin use. Four studies (three randomized controlled trials and one cohort) reported on adults with SAB, including 54 patients treated with adjunctive rifampicin and 44 standard-therapy controls. Estimated across all of these studies, adjunctive rifampicin was associated with trends towards reduced all-cause mortality and reduced clinical or bacteriological failure. The fifth study indicated that adjunctive rifampicin accelerates the resolution of persistent SAB in neonates. Data from the sixth study were considered flawed owing to differences in co-morbidities between groups. Limited data suggest that rifampicin-induced hepatitis is not clinically significant but that drug interactions are. In conclusion, adjunctive rifampicin may improve outcomes in SAB when used as an adjunct to β-lactam or glycopeptide monotherapy.
Risk factors associated with bovine trichomoniasis in beef cattle identified by a questionnaire
Authors: Jin Yinzhu , Schumaker Brant , Logan Jim , Yao Chaoqun
Published: March 2014

Bovine trichomoniasis is a venereal disease that causes substantial economic losses to the cattle industry worldwide. It has been endemic in the USA since its discovery in the 1930s. The reasons for this long-lasting endemism are poorly understood. The main objective of this study was to identify herd-level risk factors for trichomoniasis in Wyoming beef cattle. A questionnaire was sent to all Wyoming beef cattle producers. The overall response proportion was 23.4 %. Questionnaires were returned from producers throughout the state in different geographical regions and with various herd sizes. In total, 863 questionnaires were analysed for correlation between the disease endemism and 25 variables.Tritrichomonas foetusinfections were found to be significantly (P<0.05) associated with neighbouring a positive herd(s), grazing on public allotments and commingling with other herds. In addition, a delay in fixing broken fences approached statistical significance (P = 0.078). This study provides producers with valuable information and useful suggestions on how to effectively control and reduce the risks of bovine trichomoniasis.
DNA compaction in the early part of the SOS response is dependent on RecN and RecA
Authors: Odsbu Ingvild , Skarstad Kirsten
Published: March 2014

The nucleoids of undamagedEscherichia colicells have a characteristic shape and number, which is dependent on the growth medium. Upon induction of the SOS response by a low dose of UV irradiation an extensive reorganization of the nucleoids occurred. Two distinct phases were observed by fluorescence microscopy. First, the nucleoids were found to change shape and fuse into compact structures at midcell. The compaction of the nucleoids lasted for 10–20 min and was followed by a phase where the DNA was dispersed throughout the cells. This second phase lasted for ~1 h. The compaction was found to be dependent on the recombination proteins RecA, RecO and RecR as well as the SOS-inducible, SMC (structural maintenance of chromosomes)-like protein RecN. RecN protein is produced in high amounts during the first part of the SOS response. It is possible that the RecN-mediated ‘compact DNA’ stage at the beginning of the SOS response serves to stabilize damaged DNA prior to recombination and repair.
Filament formation by metabolic enzymes is a specific adaptation to an advanced state of cellular starvation
Authors: Petrovska Ivana , Nüske Elisabeth , Munder Matthias C. , Kulasegaran Gayathrie , Malinovska Liliana , Kroschwald Sonja , Richter Doris , Fahmy Karim , Gibson Kimberley , Verbavatz Jean-Marc , Alberti Simon
Published: March 2014

One of the key questions in biology is how the metabolism of a cell responds to changes in the environment. In budding yeast, starvation causes a drop in intracellular pH, but the functional role of this pH change is not well understood. Here, we show that the enzyme glutamine synthetase (Gln1) forms filaments at low pH and that filament formation leads to enzyme inactivation. Filament formation by Gln1 is a highly cooperative process, strongly dependent on macromolecular crowding, and involves back-to-back stacking of cylindrical homo-decamers into filaments that associate laterally to form higher order fibrils. Other metabolic enzymes also assemble into filaments at low pH. Hence, we propose that filament formation is a general mechanism to inactivate and store key metabolic enzymes during a state of advanced cellular starvation. These findings have broad implications for understanding the interplay between nutritional stress, the metabolism and the physical organization of a cell.
French consumer profiles' reactions to information on cod fillet products
Authors: Altintzoglou Themistoklis , Heide Morten , Carlehög Mats
Published: March 2014

Purpose

– The aims of this study were: to identify consumer segments in France, based on their use of and trust in information sources regarding the freshness of fish, to examine differences between the segments regarding use of and interest in information cues and objective and subjective knowledge, to compare the consumer segments regarding their fish consumption and fish storage behaviour and to discover how different consumer segments reacted to labels regarding the processing of cod fillet products.

Design/methodology/approach

– This paper describes how French consumers (n=485) of fish were clustered in three segments based on their use of and trust in information sources regarding the freshness of fish and then compared by means of use of and interest in various information cues, knowledge, fish consumption behaviour, age and parenthood.

Findings

– Information regarding thawed cod fillet products should be carefully communicated. Fresh fish remains at the top of consumers' aspirations, regarding fish. However, a short label indicating that fish was frozen directly after catch and thawed directly before they were put on the retailers' displays may lead to an improvement of the image of previously frozen cod fillet products.

Research limitations/implications

– This survey based study could be confirmed in a real-life experimental setting.

Practical implications

– The results can be direct advice for the development of communication strategies for the successful launching of fresh and thawed cod fillet products in the market.

Originality/value

– This manuscript expands the segmentation presented by Pieniaket al.to France. Using this segmentation as a starting point, this study demonstrates the benefits of its use in the development of directed communication strategies.
Mental health and the settings of housing support – a systematic review and conceptual model
Authors: Burgoyne Jon
Published: March 2014

Purpose

– The purpose of this qualitative systematic review is to examine how the nature and quality of housing affect adults receiving support for mental health problems, focusing on the less considered structural aspects of housing.

Design/methodology/approach

– A systematic search identified relevant research. Data consisting exclusively of service-user testimony was taken from seven studies based in varied types of accommodation in England. A synthesis was carried out using thematic analysis, and a conceptual model developed based on the themes identified from the data. A literature review examines the context, with relevant material drawn from a variety of disciplines and professions.

Findings

– There were three main determinants of whether housing was a setting that enabled users to benefit from support and enjoy a good quality of life – “autonomy”, “domain”, and “facilitation”. Secondary themes influenced these primary themes, or described respondents’ condition or feelings in relation to their housing situation. The “Tripod Model” illustrates the relationships between these themes.

Research limitations/implications

– Applying systematic review methods to qualitative material proved contentious and challenging. The model produced is a hypothesis based on limited data and requiring further investigation.

Practical implications

– The findings suggest that a balance is required to increase the chances of successful and sustainable housing outcomes for service-users.

Originality/value

– The model enables a holistic understanding of issues affecting service-users, and the interdependent nature of these. It offers a new typology based on a synthesis of data drawn from a spectrum of accommodation, which gives it a breadth a single piece of research could not encompass.
The other end of entrepreneurship: a narrative study of insolvency practice in Ireland
Authors: Timothy McCarthy Padraig , O'Riordan Chris , Griffin Ray
Published: March 2014

Purpose

– The purpose of this paper is to focus on the other end of entrepreneurship – the disassembling of enterprises by insolvency professionals.

Design/methodology/approach

– Drawing on empirical material from major insolvency practitioners (IPs) in Ireland; the paper identifies three different narrative positions – “clinical market operators”, “blame the entrepreneurs” and “professional detachment/disidentification” – that these specialists employed to story their working experiences.

Findings

– The paper suggests that IPs do not have a fixed narrative schema to narrate their professional identities, as they struggle to reconcile their professional acts with their personal ambitions. These findings point to a disconnection between the political rhetoric on risk taking and the acts perpetrated on entrepreneurs who fail, a central tension in the discourse on entrepreneurship policy.

Research limitations/implications

– The paper adds to the current debate on business failure, an area that is typically under-researched and under-theorised in entrepreneurship studies. By offering a response to calls for more multi-perspective research, this paper makes a significant contribution to extant interpretive literature on business failure. While the method of analysing stories is widely accepted in social science research, researchers seeking to replicate this study may produce different results; this is a taken for granted outcome of the method.

Practical implications

– The analysis suggests that the current legislative impetus to ameliorate the implications of insolvency, driven by an aspiration to encourage second-chance entrepreneurship, faces resistance from IPs as they attempt to fulfil their professional obligations. In the absence of legislative reform, the impulse, perhaps even process necessity, of IPs to dialogically position themselves against failed entrepreneurs is likely to continue.

Originality/value

– The paper's originality and value arise from its unique consideration of other end of entrepreneurship; offering novel insights into the difficulties IPs have in narrating their working lives.
The use of maturity models in improving project management performance
Authors: Brookes Naomi , Butler Michael , Dey Prasanta , Clark Robin
Published: March 2014

Purpose

– The purpose of the paper was to conduct an empirical investigation to explore the impact of project management maturity models (PMMMs) on improving project performance.

Design/methodology/approach

– The investigation used a cross-case analysis involving over 90 individuals in seven organisations.

Findings

– The findings of the empirical investigation indicate that PMMMs demonstrate very high levels of variability in individual's assessment of project management maturity. Furthermore, at higher levels of maturity, the type of performance improvement adopted following their application is related to the type of PMMM used in the assessment. The paradox of the unreliability of PMMMs and their widespread acceptance is resolved by calling upon the “wisdom of crowds” phenomenon which has implications for the use of maturity model assessments in other arena.

Research limitations/implications

– The investigation does have the usual issues associated with case research, but the steps that have been taken in the cross-case construction and analysis have improved the overall robustness and extendibility of the findings.

Practical implications

– The tendency for PMMMs to shape improvements based on their own inherent structure needs further understanding.

Originality/value

– The use of empirical methods to investigate the link between project maturity models and extant changes in project management performance is highly novel and the findings that result from this have added resonance.
An investigation of organic mixed coolant (Palm Olein) for green machining
Authors: Lee T.S. , How C.F. , Lin Y.J. , Ting T.O.
Published: March 2014

Purpose

– The purpose of this paper is to investigate and contribute to a better understanding of cutting process characteristics using the proposed RBD Palm Olein-based organic mixed coolant.

Design/methodology/approach

– In this research, refined, bleached and deodorized (RBD) Palm Olein is selected as the base oil for organic coolant and mixed coolant (base oil mixed with chemicals) to compare with the cutting performance of industrial water-soluble chemical (inorganic) coolant. Using coated carbide tool, JIS SS400 Mild Steel was tested in milling process. At fixed spindle speed, the relations between feed rate and depth of cut (DOC) on cutting temperature and surface roughness were investigated. Also, the dynamic viscosity, specific heat capacity and pH level for each coolant are taken into consideration.

Findings

– As predicted, cutting fluid with lower viscosity removes more heat. The cutting temperature increased with increasing feed rate and DOC. However, surface roughness increased with increasing feed rate but decreased with increasing DOC. From the data gathered, the proposed RBD Palm Olein-based organic mixed coolant showed better heat removal properties than organic coolant and it produced a far better machined surface than inorganic coolant.

Originality/value

– Overall, the proposed organic mixed coolant has shown great potential to be a good cutting fluid when balance between cooling properties and lubricity, and consistent quality of cutting fluids are sought to produce environmental friendly quality workpiece.