bluuebunny/crossref_metadata_2025 huggingface dataset:
ABORTED MICROSPORESActs as a Master Regulator of Pollen Wall Formation inArabidopsis
Authors: Xu Jie , Ding Zhiwen , Vizcay-Barrena Gema , Shi Jianxin , Liang Wanqi , Yuan Zheng , Werck-Reichhart Danièle , Schreiber Lukas , Wilson Zoe A. , Zhang Dabing
Published: April 2014

Mature pollen is covered by durable cell walls, principally composed of sporopollenin, an evolutionary conserved, highly resilient, but not fully characterized, biopolymer of aliphatic and aromatic components. Here, we report that ABORTED MICROSPORES (AMS) acts as a master regulator coordinating pollen wall development and sporopollenin biosynthesis in Arabidopsis thaliana. Genome-wide coexpression analysis revealed 98 candidate genes with specific expression in the anther and 70 that showed reduced expression in ams. Among these 70 members, we showed that AMS can directly regulate 23 genes implicated in callose dissociation, fatty acids elongation, formation of phenolic compounds, and lipidic transport putatively involved in sporopollenin precursor synthesis. Consistently, ams mutants showed defective microspore release, a lack of sporopollenin deposition, and a dramatic reduction in total phenolic compounds and cutin monomers. The functional importance of the AMS pathway was further demonstrated by the observation of impaired pollen wall architecture in plant lines with reduced expression of several AMS targets: the abundant pollen coat protein extracellular lipases (EXL5 and EXL6), and CYP98A8 and CYP98A9, which are enzymes required for the production of phenolic precursors. These findings demonstrate the central role of AMS in coordinating sporopollenin biosynthesis and the secretion of materials for pollen wall patterning.
Accurate macromolecular crystallographic refinement: incorporation of the linear scaling, semiempirical quantum-mechanics programDivConinto thePHENIXrefinement package
Authors: Borbulevych Oleg Y. , Plumley Joshua A. , Martin Roger I. , Merz Kenneth M. , Westerhoff Lance M.
Published: April 2014

Macromolecular crystallographic refinement relies on sometimes dubious stereochemical restraints and rudimentary energy functionals to ensure the correct geometry of the model of the macromolecule and any covalently bound ligand(s). The ligand stereochemical restraint file (CIF) requiresa prioriunderstanding of the ligand geometry within the active site, and creation of the CIF is often an error-prone process owing to the great variety of potential ligand chemistry and structure. Stereochemical restraints have been replaced with more robust functionals through the integration of the linear-scaling, semiempirical quantum-mechanics (SE-QM) programDivConwith thePHENIXX-ray refinement engine. ThePHENIX/DivConpackage has been thoroughly validated on a population of 50 protein–ligand Protein Data Bank (PDB) structures with a range of resolutions and chemistry. The PDB structures used for the validation were originally refined utilizing various refinement packages and were published within the past five years.PHENIX/DivCondoes not utilize CIF(s), link restraints and other parameters for refinement and hence it does not make as manya prioriassumptions about the model. Across the entire population, the method results in reasonable ligand geometries and low ligand strains, even when the original refinement exhibited difficulties, indicating thatPHENIX/DivConis applicable to both single-structure and high-throughput crystallography.
Sunitinib: from charge-density studies to interaction with proteins
Authors: Malińska Maura , Jarzembska Katarzyna N. , Goral Anna M. , Kutner Andrzej , Woźniak Krzysztof , Dominiak Paulina M.
Published: April 2014

Protein kinases are targets for the treatment of a number of diseases. Sunitinib malate is a type I inhibitor of tyrosine kinases and was approved as a drug in 2006. This contribution constitutes the first comprehensive analysis of the crystal structures of sunitinib malate and of complexes of sunitinib with a series of protein kinases. The high-resolution single-crystal X-ray measurement and aspherical atom databank approach served as a basis for reconstruction of the charge-density distribution of sunitinib and its protein complexes. Hirshfeld surface and topological analyses revealed a similar interaction pattern in the sunitinib malate crystal structure to that in the protein binding pockets. Sunitinib forms nine preserved bond paths corresponding to hydrogen bonds and also to the C—H...O and C—H...π contacts common to the VEGRF2, CDK2, G2, KIT and IT kinases. In general, sunitinib interacts with the studied proteins with a similar electrostatic interaction energy and can adjust its conformation to fit the binding pocket in such a way as to enhance the electrostatic interactions,e.g.hydrogen bonds in ligand–kinase complexes. Such behaviour may be responsible for the broad spectrum of action of sunitinib as a kinase inhibitor.
Divalent metal ion-based catalytic mechanism of the Nudix hydrolase Orf153 (YmfB) fromEscherichia coli
Authors: Hong Myoung-Ki , Ribeiro António J. M. , Kim Jin-Kwang , Ngo Ho-Phuong-Thuy , Kim Jiyoung , Lee Choong Hwan , Ahn Yeh-Jin , Fernandes Pedro Alexandrino , Li Qing , Ramos Maria Joao , Kang Lin-Woo
Published: April 2014

YmfB fromEscherichia coliis the Nudix hydrolase involved in the metabolism of thiamine pyrophosphate, an important compound in primary metabolism and a cofactor of many enzymes. In addition, it hydrolyzes (d)NTPs to (d)NMPs and inorganic orthophosphates in a stepwise manner. The structures of YmfB alone and in complex with three sulfates and two manganese ions determined by X-ray crystallography, when compared with the structures of other Nudix hydrolases such as MutT, Ap4Aase and DR1025, provide insight into the unique hydrolysis mechanism of YmfB. Mass-spectrometric analysis confirmed that water attacks the terminal phosphates of GTP and GDP sequentially. Kinetic analysis of binding-site mutants showed that no individual residue is absolutely required for catalytic activity, suggesting that protein residues do not participate in the deprotonation of the attacking water. Thermodynamic integration calculations show that a hydroxyl ion bound to two divalent metal ions attacks the phosphate directly without the help of a nearby catalytic base.
Bacteriophage P22 tailspike: structure of the complete protein and function of the interdomain linker
Authors: Seul Anaït , Müller Jürgen J. , Andres Dorothee , Stettner Eva , Heinemann Udo , Seckler Robert
Published: April 2014

Attachment of phages to host cells, followed by phage DNA ejection, represents the first stage of viral infection of bacteria.Salmonellaphage P22 has been extensively studied, serving as an experimental model for bacterial infection by phages. P22 engages bacteria by binding to the sugar moiety of lipopolysaccharides using the viral tailspike protein for attachment. While the structures of the N-terminal particle-binding domain and the major receptor-binding domain of the tailspike have been analyzed individually, the three-dimensional organization of the intact protein, including the highly conserved linker region between the two domains, remained unknown. A single amino-acid exchange in the linker sequence made it possible to crystallize the full-length protein. Two crystal structures of the linker region are presented: one attached to the N-terminal domain and the other present within the complete tailspike protein. Both retain their biological function, but the mutated full-length tailspike displays a retarded folding pathway. Fitting of the full-length tailspike into a published cryo-electron microscopy map of the P22 virion requires an elastic distortion of the crystal structure. The conservation of the linker suggests a role in signal transmission from the distal tip of the molecule to the phage head, eventually leading to DNA ejection.
Structure of sulfamidase provides insight into the molecular pathology of mucopolysaccharidosis IIIA
Authors: Sidhu Navdeep S. , Schreiber Kathrin , Pröpper Kevin , Becker Stefan , Usón Isabel , Sheldrick George M. , Gärtner Jutta , Krätzner Ralph , Steinfeld Robert
Published: April 2014

Mucopolysaccharidosis type IIIA (Sanfilippo A syndrome), a fatal childhood-onset neurodegenerative disease with mild facial, visceral and skeletal abnormalities, is caused by an inherited deficiency of the enzyme N-sulfoglucosamine sulfohydrolase (SGSH; sulfamidase). More than 100 mutations in the SGSH gene have been found to reduce or eliminate its enzymatic activity. However, the molecular understanding of the effect of these mutations has been confined by a lack of structural data for this enzyme. Here, the crystal structure of glycosylated SGSH is presented at 2 Å resolution. Despite the low sequence identity between this unique N-sulfatase and the group of O-sulfatases, they share a similar overall fold and active-site architecture, including a catalytic formylglycine, a divalent metal-binding site and a sulfate-binding site. However, a highly conserved lysine in O-sulfatases is replaced in SGSH by an arginine (Arg282) that is positioned to bind the N-linked sulfate substrate. The structure also provides insight into the diverse effects of pathogenic mutations on SGSH function in mucopolysaccharidosis type IIIA and convincing evidence for the molecular consequences of many missense mutations. Further, the molecular characterization of SGSH mutations will lay the groundwork for the development of structure-based drug design for this devastating neurodegenerative disorder.
A novel β-xylosidase structure fromGeobacillus thermoglucosidasius: the first crystal structure of a glycoside hydrolase family GH52 enzyme reveals unpredicted similarity to other glycoside hydrolase folds
Authors: Espina Giannina , Eley Kirstin , Pompidor Guillaume , Schneider Thomas R. , Crennell Susan J. , Danson Michael J.
Published: April 2014

Geobacillus thermoglucosidasiusis a thermophilic bacterium that is able to ferment both C6 and C5 sugars to produce ethanol. During growth on hemicellulose biomass, an intracellular β-xylosidase catalyses the hydrolysis of xylo-oligosaccharides to the monosaccharide xylose, which can then enter the pathways of central metabolism. The gene encoding aG. thermoglucosidasiusβ-xylosidase belonging to CAZy glycoside hydrolase family GH52 has been cloned and expressed inEscherichia coli. The recombinant enzyme has been characterized and a high-resolution (1.7 Å) crystal structure has been determined, resulting in the first reported structure of a GH52 family member. A lower resolution (2.6 Å) structure of the enzyme–substrate complex shows the positioning of the xylobiose substrate to be consistent with the proposed retaining mechanism of the family; additionally, the deep cleft of the active-site pocket, plus the proximity of the neighbouring subunit, afford an explanation for the lack of catalytic activity towards the polymer xylan. Whilst the fold of theG. thermoglucosidasiusβ-xylosidase is completely different from xylosidases in other CAZy families, the enzyme surprisingly shares structural similarities with other glycoside hydrolases, despite having no more than 13% sequence identity.
Structural basis of sialidase in complex with geranylated flavonoids as potent natural inhibitors
Authors: Lee Youngjin , Ryu Young Bae , Youn Hyung-Seop , Cho Jung Keun , Kim Young Min , Park Ji-Young , Lee Woo Song , Park Ki Hun , Eom Soo Hyun
Published: April 2014

Sialidase catalyzes the removal of a terminal sialic acid from glycoconjugates and plays a pivotal role in nutrition, cellular interactions and pathogenesis mediating various infectious diseases including cholera, influenza and sepsis. An array of antiviral sialidase agents have been developed and are commercially available, such as zanamivir and oseltamivir for treating influenza. However, the development of bacterial sialidase inhibitors has been much less successful. Here, natural polyphenolic geranylated flavonoids which show significant inhibitory effects againstCp-NanI, a sialidase fromClostridium perfringens, are reported. This bacterium causes various gastrointestinal diseases. The crystal structure of theCp-NanI catalytic domain in complex with the best inhibitor, diplacone, is also presented. This structure explains how diplacone generates a stable enzyme–inhibitor complex. These results provide a structural framework for understanding the interaction between sialidase and natural flavonoids, which are promising scaffolds on which to discover new anti-sialidase agents.
Fingerprinting redox and ligand states in haemprotein crystal structures using resonance Raman spectroscopy
Authors: Kekilli Demet , Dworkowski Florian S. N. , Pompidor Guillaume , Fuchs Martin R. , Andrew Colin R. , Antonyuk Svetlana , Strange Richard W. , Eady Robert R. , Hasnain S. Samar , Hough Michael A.
Published: April 2014

It is crucial to assign the correct redox and ligand states to crystal structures of proteins with an active redox centre to gain valid functional information and prevent the misinterpretation of structures. Single-crystal spectroscopies, particularly when appliedin situat macromolecular crystallography beamlines, allow spectroscopic investigations of redox and ligand states and the identification of reaction intermediates in protein crystals during the collection of structural data. Single-crystal resonance Raman spectroscopy was carried out in combination with macromolecular crystallography on Swiss Light Source beamline X10SA using cytochromec′ fromAlcaligenes xylosoxidans. This allowed the fingerprinting and validation of different redox and ligand states, identification of vibrational modes and identification of intermediates together with monitoring of radiation-induced changes. This combined approach provides a powerful tool to obtain complementary data and correctly assign the true oxidation and ligand state(s) in redox-protein crystals.
Structural analysis and insight into metal-ion activation of the iron-dependent regulator fromThermoplasma acidophilum
Authors: Yeo Hyun Ku , Park Young Woo , Lee Jae Young
Published: April 2014

The iron-dependent regulator (IdeR) is a metal ion-activated transcriptional repressor that regulates the expression of genes encoding proteins involved in iron uptake to maintain metal-ion homeostasis. IdeR is a functional homologue of the diphtheria toxin repressor (DtxR), and both belong to the DtxR/MntR family of metalloregulators. The structure of Fe2+-bound IdeR (TA0872) fromThemoplasma acidophilumwas determined at 2.1 Å resolution by X-ray crystallography using single-wavelength anomalous diffraction. The presence of Fe2+, which is the true biological activator of IdeR, in the metal-binding site was ascertained by the use of anomalous difference electron-density maps using diffraction data collected at the Fe absorption edge. Each DtxR/IdeR subunit contains two metal ion-binding sites separated by 9 Å, labelled the primary and ancillary sites, whereas the crystal structures of IdeR fromT. acidophilumshow a binuclear iron cluster separated by 3.2 Å, which is novel toT. acidophilumIdeR. The metal-binding site analogous to the primary site in DtxR was unoccupied, and the ancillary site was occupied by binuclear clustered ions. This difference suggests thatT. acidophilumIdeR and its closely related homologues are regulated by a mechanism distinct from that of either DtxR or MntR.T. acidophilumIdeR was also shown to have a metal-dependent DNA-binding property by electrophoretic mobility shift assay.
Insights into the binding specificity and catalytic mechanism ofN-acetylhexosamine 1-phosphate kinases through multiple reaction complexes
Authors: Wang Kuei-Chen , Lyu Syue-Yi , Liu Yu-Chen , Chang Chin-Yuan , Wu Chang-Jer , Li Tsung-Lin
Published: April 2014

Utilization ofN-acetylhexosamine in bifidobacteria requires the specific lacto-N-biose/galacto-N-biose pathway, a pathway differing from the Leloir pathway while establishing symbiosis between humans and bifidobacteria. The genelnpBin the pathway encodes a novel hexosamine kinase NahK, which catalyzes the formation ofN-acetylhexosamine 1-phosphate (GlcNAc-1P/GalNAc-1P). In this report, seven three-dimensional structures of NahK in complex with GlcNAc, GalNAc, GlcNAc-1P, GlcNAc/AMPPNP and GlcNAc-1P/ADP from bothBifidobacterium longum(JCM1217) andB. infantis(ATCC15697) were solved at resolutions of 1.5–2.2 Å. NahK is a monomer in solution, and its polypeptide folds in a crescent-like architecture subdivided into two domains by a deep cleft. The NahK structures presented here represent the first multiple reaction complexes of the enzyme. This structural information reveals the molecular basis for the recognition of the given substrates and products, GlcNAc/GalNAc, GlcNAc-1P/GalNAc-1P, ATP/ADP and Mg2+, and provides insights into the catalytic mechanism, enabling NahK and mutants thereof to form a choice of biocatalysts for enzymatic and chemoenzymatic synthesis of carbohydrates.
The structure of a novel electron-transfer ferredoxin fromRhodopseudomonas palustrisHaA2 which contains a histidine residue in its iron–sulfur cluster-binding motif
Authors: Zhang Ting , Zhang Aili , Bell Stephen G. , Wong Luet-Lok , Zhou Weihong
Published: April 2014

Rhodopseudomonas palustrisHaA2 contains a gene,RPB3630, encoding a ferredoxin, HaPuxC, with an atypical CXXHXXC(X)nCP iron–sulfur cluster-binding motif. The ferredoxin gene is associated with a cytochrome P450 (CYP) monooxygenase-encoding gene, CYP194A3, an arrangement which is conserved in several strains of bacteria. Similar ferredoxin genes are found in other bacteria, such asMycobacterium tuberculosis, where they are also associated with CYP genes. The crystal structure of HaPuxC has been solved at 2.3 Å resolution. The overall fold of this [3Fe–4S] cluster-containing ferredoxin is similar to other [3Fe–4S] and [4Fe–4S] species, with the loop around the iron–sulfur cluster more closely resembling those of [3Fe–4S] ferredoxins. The side chain of His17 from the cluster-binding motif in HaPuxC points away from the vacant site of the cluster and interacts with Glu61 and one of the sulfide ions of the cluster. This is the first cytochrome P450 electron-transfer partner of this type to be structurally characterized and will provide a better understanding of the electron-transfer processes between these ferredoxins and their CYP enzymes.
Crystallographic and kinetic study of riboflavin synthase fromBrucella abortus, a chemotherapeutic target with an enhanced intrinsic flexibility
Authors: Serer María I. , Bonomi Hernán R. , Guimarães Beatriz G. , Rossi Rolando C. , Goldbaum Fernando A. , Klinke Sebastián
Published: April 2014

Riboflavin synthase (RS) catalyzes the last step of riboflavin biosynthesis in microorganisms and plants, which corresponds to the dismutation of two molecules of 6,7-dimethyl-8-ribityllumazine to yield one molecule of riboflavin and one molecule of 5-amino-6-ribitylamino-2,4(1H,3H)-pyrimidinedione. Owing to the absence of this enzyme in animals and the fact that most pathogenic bacteria show a strict dependence on riboflavin biosynthesis, RS has been proposed as a potential target for antimicrobial drug development. Eubacterial, fungal and plant RSs assemble as homotrimers lackingC3symmetry. Each monomer can bind two substrate molecules, yet there is only one active site for the whole enzyme, which is located at the interface between two neighbouring chains. This work reports the crystallographic structure of RS from the pathogenic bacteriumBrucella abortus(the aetiological agent of the disease brucellosis) in its apo form, in complex with riboflavin and in complex with two different product analogues, being the first time that the structure of an intact RS trimer with bound ligands has been solved. These crystal models support the hypothesis of enhanced flexibility in the particle and also highlight the role of the ligands in assembling the unique active site. Kinetic and binding studies were also performed to complement these findings. The structural and biochemical information generated may be useful for the rational design of novel RS inhibitors with antimicrobial activity.
Structure of the unique SEFIR domain from human interleukin 17 receptor A reveals a composite ligand-binding site containing a conserved α-helix for Act1 binding and IL-17 signaling
Authors: Zhang Bing , Liu Caini , Qian Wen , Han Yue , Li Xiaoxia , Deng Junpeng
Published: April 2014

Interleukin 17 (IL-17) cytokines play a crucial role in mediating inflammatory and autoimmune diseases. A unique intracellular signaling domain termed SEFIR is found within all IL-17 receptors (IL-17Rs) as well as the key adaptor protein Act1. SEFIR-mediated protein–protein interaction is a crucial step in IL-17 cytokine signaling. Here, the 2.3 Å resolution crystal structure of the SEFIR domain of IL-17RA, the most commonly shared receptor for IL-17 cytokine signaling, is reported. The structure includes the complete SEFIR domain and an additional α-helical C-terminal extension, which pack tightly together to form a compact unit. Structural comparison between the SEFIR domains of IL-17RA and IL-17RB reveals substantial differences in protein topology and folding. The uniquely long insertion between strand βC and helix αC in IL-17RA SEFIR is mostly well ordered, displaying a helix (αCC′ins) and a flexible loop (CC′). The DD′ loop in the IL-17RA SEFIR structure is much shorter; it rotates nearly 90° with respect to the counterpart in the IL-17RB SEFIR structure and shifts about 12 Å to accommodate the αCC′inshelix without forming any knots. Helix αC was identified as critical for its interaction with Act1 and IL-17-stimulated gene expression. The data suggest that the heterotypic SEFIR–SEFIR associationviahelix αC is a conserved and signature mechanism specific for IL-17 signaling. The structure also suggests that the downstream motif of IL-17RA SEFIR together with helix αC could provide a composite ligand-binding surface for recruiting Act1 during IL-17 signaling.
Structural characterization of the apo form and NADH binary complex of human lactate dehydrogenase
Authors: Dempster Sally , Harper Stephen , Moses John E. , Dreveny Ingrid
Published: April 2014

Lactate dehydrogenase A (LDH-A) is a key enzyme in anaerobic respiration that is predominantly found in skeletal muscle and catalyses the reversible conversion of pyruvate to lactate in the presence of NADH. LDH-A is overexpressed in many tumours and has therefore emerged as an attractive target for anticancer drug discovery. Crystal structures of human LDH-A in the presence of inhibitors have been described, but currently no structures of the apo or binary NADH-bound forms are available for any mammalian LDH-A. Here, the apo structure of human LDH-A was solved at a resolution of 2.1 Å in space groupP4122. The active-site loop adopts an open conformation and the packing and crystallization conditions suggest that the crystal form is suitable for soaking experiments. The soaking potential was assessed with the cofactor NADH, which yielded a ligand-bound crystal structure in the absence of any inhibitors. The structures show that NADH binding induces small conformational changes in the active-site loop and an adjacent helix. A comparison with other eukaryotic apo LDH structures reveals the conservation of intra-loop interactions. The structures provide novel insight into cofactor binding and provide the foundation for soaking experiments with fragments and inhibitors.
Structural and functional characterization of an Isd-type haem-degradation enzyme fromListeria monocytogenes. Corrigendum
Authors: Duong Thao , Park Kwangsu , Kim Truc , Kang Sung Wook , Hahn Myong-Joon , Hwang Hye-Yeon , Jang Inae , Oh Han Bin , Kim Kyeong Kyu
Published: April 2014

The author list in Duonget al.[(2014).Acta Cryst.D70, 615–626] is corrected.
Crystallization and preliminary crystallographic analysis of Axe2, an acetylxylan esterase fromGeobacillus stearothermophilus. Corrigendum
Authors: Lansky Shifra , Alalouf Onit , Solomon Vered , Alhassid Anat , Govada Lata , Chayen Naomi E. , Belrhali Hassan , Shoham Yuval , Shoham Gil
Published: April 2014

The article by Lanskyet al.[(2013),Acta Cryst.F69, 430–434] is corrected.
Measuring skills in Europe
Authors: Martinaitis Žilvinas
Published: April 2014

Purpose

– “Skills” is a central concept in a number of academic and policy debates. Yet measurement of skills of labour force remains highly problematic. The dominant approach uses signals of individual capacities (e.g. level of education) as a proxy of skills. This paper develops and tests a methodology for more direct measurement of skills by focusing on how individuals perform their tasks rather than what they could be capable of doing.

Design/methodology/approach

– The proposed theoretical framework assumes that skills used at workplace represent the skills an individual has. This is captured by the analysis of how tasks are performed. Level of skills-in-use is measured at three dimensions: degree of uncertainty, level of autonomy and opportunities for continuous skill-building. Empirical analysis utilises survey data on 29 European countries.

Findings

– First, the paper proposes a novel methodology for measuring skills. Second, it uses data from European Working Conditions Survey to measure skills of workforce in 29 European countries.

Research limitations/implications

– The depth of indicators used for measurement of skills could be further expanded, if additional questions could be inserted in the pan-European surveys.

Practical implications

– Findings suggest that the quality of employment domain (tasks, technologies, work organisation, etc.) could be as important as formal education systems in upgrading the skills of labour force.

Originality/value

– The paper proposes and tests a methodology for more direct measurement of skills than the ones previously employed in academic and policy debates.
Learning outcomes of a work-based training programme
Authors: Ellström Eva , Ellström Per-Erik
Published: April 2014

Purpose

– The purpose of this study was to explore the extent to which first-line managers' (FLMs') support of employee learning activities influence the learning outcomes and the transfer of training from a work-based vocational education and training (VET) programme.

Design/methodology/approach

– The study was designed as a multiple-case study including six service units in elder care. Data were collected through interviews with managers and care workers in the six units.

Findings

– The study demonstrated that the role of FLMs was a significant condition for the learning outcomes attained and for positive transfer of training. For care workers to attain benefits from training that went beyond the individual level, that is, benefits at the level of the work team or the organisation, a supportive FLM role appeared to be necessary.

Research limitations/implications

– The statistical generalisability of the study is limited by its character of a multiple-case study of six work units. At the same time, a strength of the study lies in its potential for analytic generalisations, that is, for identifying and verifying theoretically meaningful patterns across a number of cases.

Practical implications

– The findings suggest a need for management development that promotes a broader understanding of the task as FLM, and, specifically, improved knowledge and skills regarding how to lead and organise learning and development processes in a workplace.

Originality/value

– Using a qualitative approach, this study adds to the limited knowledge of FLMs' influences on the learning outcomes and the positive transfer from work-based training.
The role of maintenance and facility management in logistics: a literature review
Authors: Mangano Giulio , De Marco Alberto
Published: April 2014

Purpose

– The purpose of this paper is to provide a literature review on the different ways of carrying out facility management and related topics in order to uncover that there is limited research regarding the impact of facility management on the logistics and operational performance of warehouses.

Design/methodology/approach

– Four different focus areas have been identified and for each one different methodologies and streams of research have been studied.

Findings

– The study underlines the importance of facility management for the logistics operations; therefore it supports the notion that investments aiming at preserving the status of the building and service components of warehouses are crucial.

Originality/value

– This paper aims to suggest to facilities management managers that they can contribute to enhance business performance by designing effective facility management strategies.
Safety climate and injury occurrence of repair, maintenance, minor alteration and addition works
Authors: K.H. Hon Carol , Hinze Jimmie , P.C. Chan Albert
Published: April 2014

Purpose

– The repair, maintenance, minor alteration and addition (RMAA) sector has been expanding in many developed cities. Safety problems of the RMAA sector have attracted the attention of many governments. This study has the objectives of comparing the level of safety climate of workers, supervisors and managers in the RMAA sector; and explaining/predicting the impact of safety climate on injury occurrence of workers, supervisors and managers.

Design/methodology/approach

– A questionnaire survey was administered to RMAA contracting companies in Hong Kong.

Findings

– When comparing the safety climate perception of workers, supervisors and managers in the RMAA sector, the supervisors group had the lowest mean safety climate score. Results showed that a positive workforce safety attitude and acceptance of safety rules and regulations reduced the workers' likelihood of having injuries. A reasonable production schedule led to a lower probability of supervisors being injured. Management commitment and effective safety management reduced the probability of managers being injured.

Originality/value

– This study revealed variations of safety climate at the different levels in the organizational hierarchy and their varying influence on safety performance of the RMAA sector. Safety of RMAA works could be improved by promulgating specific safety measures at the different hierarchy levels.
Gender and entrepreneurial self-efficacy: a learning perspective
Authors: Dempsey Dianna , Jennings Jennifer
Published: April 2014

Purpose

– The purpose of this study was to investigate whether the four major factors known to contribute to self-efficacy in general (enactive mastery, vicarious experience, physiological arousal and verbal persuasion) can help account for observed differences in the entrepreneurial self-efficacy (ESE) of young women and men, in particular.

Design/methodology/approach

– The authors adopted a two-stage design, which included collecting data from 222 university students via an online survey followed by a quasi-experiment involving an opportunity evaluation task.

Findings

– The findings demonstrate that the significantly lower ESE of the young women in the sample was attributable to their lower level of prior entrepreneurial experience, their lower level of positive and negative affect towards entrepreneurship and their higher likelihood of receiving failure feedback due to their actual performance on an opportunity evaluation task.

Research limitations/implications

– Given the importance of understanding why females continue to be under-represented in entrepreneurial activity the world over, these findings provide additional insight into why young women tend to feel less efficacious than young men about their ability to successfully undertake an entrepreneurial career.

Originality/value

– This paper offers a comprehensive and unified theoretical framework, derived from social learning theory, for furthering the understanding of the factors that contribute to gender differences in ESE. The authors also offer a novel quasi-experimental design involving an opportunity evaluation task that others might find useful, particularly for empirical research adopting a cognitive and/or affective lens on entrepreneurship.
Technology and medication errors: impact in nursing homes
Authors: Baril Chantal , Gascon Viviane , St-Pierre Liette , Lagacé Denis
Published: April 2014

Purpose

– The purpose of this paper is to study a medication distribution technology's (MDT) impact on medication errors reported in public nursing homes in Québec Province.

Design/methodology/approach

– The work was carried out in six nursing homes (800 patients). Medication error data were collected from nursing staff through a voluntary reporting process before and after MDT was implemented. The errors were analysed using: totals errors; medication error type; severity and patient consequences. A statistical analysis verified whether there was a significant difference between the variables before and after introducing MDT.

Findings

– The results show that the MDT detected medication errors. The authors' analysis also indicates that errors are detected more rapidly resulting in less severe consequences for patients.

Practical implications

– MDT is a step towards safer and more efficient medication processes. Our findings should convince healthcare administrators to implement technology such as electronic prescriber or bar code medication administration systems to improve medication processes and to provide better healthcare to patients.

Originality/value

– Few studies have been carried out in long-term healthcare facilities such as nursing homes. The authors' study extends what is known about MDT's impact on medication errors in nursing homes.
Healthcare quality indicators – a systematic review
Authors: Yildiz Özkan , Demirors Onur
Published: April 2014

Purpose

– The purpose of this paper is to review the literature on quality model development, validation and limitations.

Design/methodology/approach

– The systematic literature review used online journal indexes between January 1995 and April 2010. International studies focusing on multiple functional domains and those in which development methods were selected. Two reviewers assessed all studies and 18 were shortlisted.

Findings

– Literature reviews, peer reviews, questionnaires and expert panels are the most frequently used model development methods. Expert judges were widely used to validate the models. The most important limitation was that key indicators were missing.

Originality/value

– Existing healthcare quality models are not comprehensive and there is no consensus on targets, clinical areas or diseases.
Burnout syndrome during residency in internal medicine and pediatrics in a country without working time directive
Authors: Yazgan Aksoy Duygu , Durusu Tanriover Mine , Unal Sule , Dizdar Omer , Kalyoncu Umut , Karakaya Jale , Unal Serhat , Kale Gulsev
Published: April 2014

Purpose

– The purpose of this paper is to demonstrate burnout syndrome among internal medicine and pediatrics residents in a country that does not have the working time directive (WTD) and also to determine the risk factors and consequent impact on efficient functioning in clinical areas.

Design/methodology/approach

– A 57-item questionnaire was given to internal medicine and pediatrics residents. Responses from 22 pediatrics and 33 internal medicine residents were evaluated.

Findings

– Demographic findings, burnout scores, having hobbies, social activities and reading books unrelated to medicine were similar between the two groups. Six pediatrics residents (27.3 per cent) and 11 (33.3 per cent) internal medicine residents met the criteria for clinically significant burnout. Personal accomplishment scores and reading books unrelated to medicine were found to be related to burnout.

Originality/value

– Burnout is a syndrome characterized by depersonalization, emotional exhaustion and a low sense of personal accomplishment. It is important to document burnout in countries where WTDs are not implemented. Further studies might demonstrate burnout's effect on patient safety, service quality and physician's performance.
Bullying behaviours among mentally disordered offenders in a medium secure unit
Authors: Gakhal Baldeesh , Oddie Sharon
Published: April 2014

Purpose

– The purpose of this paper is to explore the nature and prevalence of bullying behaviours and victimisation experiences among mentally disordered offenders within a medium secure unit (MSU).

Design/methodology/approach

– In all, 35 adult male patients completed the Direct and Indirect Patient behaviour Checklist-Hospital Version (DIPC-H).

Findings

– Indirect aggression was reported more frequently than direct aggression, although there was no statistically significant difference between the prevalence estimates. The most prevalent DIPC-H categories were the pure victim and not involved categories followed by bully/victim and pure bully. Membership of the pure bully category was predicted by being on a particular ward.

Research limitations/implications

– Given that the study was a preliminary investigation into the nature and prevalence of bullying behaviours in a MSU, the sample size is limited. Consequently, it is difficult to generalise the findings. It would be useful for future research to focus on differences between levels of security using larger sample sizes to enable a greater understanding of the prevalence of bullying in secure settings and associated factors.

Practical implications

– Further evidence is provided by the current research that indirect bullying and victimisation behaviours are reported more frequently by patients. The importance of anti-bullying procedures and interventions in secure settings is emphasised and recommendations that can be applied across various forensic settings are described. Better-informed interventions can then be implemented with the aim to manage bullying behaviours in secure settings. The one “pure bully” in the current study was on a rehabilitation ward. This highlights that such behaviours occur on lesser secure wards and serves as an important reminder to ensure that staff do not become complacent.

Originality/value

– As there is only one published study to date that has focused on bullying behaviours in a MSU, the current study will contribute to the dearth of literature in this area and assist professionals working in secure settings to better understand the nature and prevalence of bullying behaviours among mentally disordered offenders.
Investment opportunity set, board independence, and firm performance
Authors: Sun Jerry , Lan George , Ma Zhenzhong
Published: April 2014

Purpose

– The purpose of this paper is to investigate the impact of Sarbanes-Oxley Act (SOX) on high growth firms’ corporate governance. Specially, the study examines whether there is a negative impact of SOX on the interactive effect of board independence and investment opportunity set on firm performance.

Design/methodology/approach

– Sample firms were selected from the Investor Responsibility Research Center Directors’ database. Both accounting- and market-based firm performance measures are used. Regressions are run to test the hypothesis.

Findings

– It was found that the impact of SOX on the interaction effect of board independence and investment opportunity set on firm performance is negative.

Originality/value

– The results suggest that the impact of SOX in corporate governance and regulatory environment mitigates the effect of board independence on the relationship between investment opportunity set and firm performance, consistent with the notion that the enactment of SOX increases monitoring costs of board governance especially for high-growth firms.
The capital structure of Chinese listed firms: is manufacturing industry special?
Authors: Tse Chin-Bun , Rodgers Timothy
Published: April 2014

Purpose

– The purpose of this paper is to examine whether or not industry membership can explain the leverage of Shanghai listed firms prior to the 2007 financial crisis. In view of the central role that manufacturing industry played in China's rise as a global economic power, the authors are particularly interested in whether or not manufacturing is a special case.

Design/methodology/approach

– The paper undertakes a comparative study of leverage differences between manufacturing and non-manufacturing industry firms on both a cross-section and time-series basis. This is supplemented by a pooled regression analysis that models the factors determining leverage on an industry-by-industry basis.

Findings

– The authors find that leverage levels differ across industries because of industry-based differences in financial characteristics. It is also found that, despite playing a leading role in China's economic development, there is no evidence to suggest that manufacturing is a special case. Across all sectors borrowing-power-related variables were identified as being important determinants of leverage and, contrary to the expectations, factors relating to profitability were largely insignificant.

Research limitations/implications

– The trade off and pecking order capital structure theories found to be commonly applicable to firms in the western business environment do not appear to adequately explain capital structure in China.

Originality/value

– The paper identify evidence to suggest that China needs to be treated as a “special case” in the context of capital structure theory due to the unique cultural and business environment.
Pushing the limits to tree height: could foliar water storage compensate for hydraulic constraints in Sequoia sempervirens?
Authors: Ishii H. Roaki , Azuma Wakana , Kuroda Keiko , Sillett Stephen C.
Published: April 2014

The constraint on vertical water transport is considered an important factor limiting height growth and maximum attainable height of trees. Here, we show evidence of foliar water storage as a mechanism that could partially compensate for this constraint in Sequoia sempervirens, the tallest species.

We measured hydraulic and morpho‐anatomical characteristics of foliated shoots of tall S. sempervirens trees near the wet, northern and dry, southern limits of its geographic distribution in California, USA.

The ability to store water (hydraulic capacitance) and saturated water content (leaf succulence) of foliage both increased with height and light availability, maintaining tolerance of leaves to water stress (bulk‐leaf water potential at turgor loss) constant relative to height.

Transverse‐sectional area of water‐storing, transfusion tissue in leaves increased with height, while the area of xylem tissue decreased, indicating increasing allocation to water storage and decreasing reliance on water transport from roots.

Treetop leaves of S. sempervirens absorb moisture via leaf surfaces and have potential to store more than five times the daily transpirational demand. Thus, foliar water storage may be an important adaptation that helps maintain physiological function of treetop leaves and hydraulic status of the crown, allowing this species to partially compensate for hydraulic constraints and sustain turgor for both photosynthesis and height growth.
Effective wavefield extrapolation in anisotropic media: accounting for resolvable anisotropy
Authors: Alkhalifah Tariq
Published: April 2014

Spectral methods provide artefact‐free and generally dispersion‐free wavefield extrapolation in anisotropic media. Their apparent weakness is in accessing the medium‐inhomogeneity information in an efficient manner. This is usually handled through a velocity‐weighted summation (interpolation) of representative constant‐velocity extrapolated wavefields, with the number of these extrapolations controlled by the effective rank of the original mixed‐domain operator or, more specifically, by the complexity of the velocity model. Conversely, with pseudo‐spectral methods, because only the space derivatives are handled in the wavenumber domain, we obtain relatively efficient access to the inhomogeneity in isotropic media, but we often resort to weak approximations to handle the anisotropy efficiently. Utilizing perturbation theory, I isolate the contribution of anisotropy to the wavefield extrapolation process. This allows us to factorize as much of the inhomogeneity in the anisotropic parameters as possible out of the spectral implementation, yielding effectively a pseudo‐spectral formulation. This is particularly true if the inhomogeneity of the dimensionless anisotropic parameters are mild compared with the velocity (i.e., factorized anisotropic media). I improve on the accuracy by using the Shanks transformation to incorporate a denominator in the expansion that predicts the higher‐order omitted terms; thus, we deal with fewer terms for a high level of accuracy. In fact, when we use this new separation‐based implementation, the anisotropy correction to the extrapolation can be applied separately as a residual operation, which provides a tool for anisotropic parameter sensitivity analysis. The accuracy of the approximation is high, as demonstrated in a complex tilted transversely isotropic model.
Special structures of hoopoe eggshells enhance the adhesion of symbiont‐carrying uropygial secretion that increase hatching success
Authors: Martín‐Vivaldi Manuel , Soler Juan J. , Peralta‐Sánchez Juan M. , Arco Laura , Martín‐Platero Antonio M. , Martínez‐Bueno Manuel , Ruiz‐Rodríguez Magdalena , Valdivia Eva
Published: April 2014

Animals live in a bacterial world, and detecting and exploring adaptations favouring mutualistic relationships with antibiotic‐producing bacteria as a strategy to fight pathogens are of prime importance for evolutionary ecologists.

Uropygial secretion of European hoopoes (Upupa epops, Linnaeus) contains antimicrobials from mutualistic bacteria that may be used to prevent embryo infection. Here, we investigated the microscopic structure of hoopoe eggshells looking for special features favouring the adhesion of antimicrobial uropygial secretions.

We impeded female access to the uropygial gland and compared microscopic characteristics of eggshells, bacterial loads of eggs and of uropygial secretion, and hatching success of experimental and control females. Then, we explored the link between microbiological characteristics of uropygial secretion and these of eggs of hoopoes, as well as possible fitness benefits.

The microscopic study revealed special structures in hoopoes' eggshells (crypts). The experimental prevention of females' gland access demonstrated that crypts are filled with uropygial secretion and that symbiotic enterococci bacteria on the eggshells come, at least partially, from those in the female's uropygial gland. Moreover, the experiment resulted in a higher permeability of eggshells by several groups of bacteria and in elimination of the positive relationships detected for control nests between hatching success and density of symbiotic bacteria, either in the uropygial secretion of females or on the eggshell.

The findings of specialized crypts on the eggshells of hoopoes, and of video‐recorded females smearing secretion containing symbiotic bacteria at a high density onto the eggshells strongly support a link between secretion and bacteria on eggs. Moreover, the detected associations between bacteria and hatching success suggest that crypts enhancing the adhesion of symbiont‐carrying uropygial secretion likely protect embryos against infections.
Journeys of patronage: moral economies of transactional sex, kinship, and female migration fromMozambique toEurope
Authors: Groes‐Green Christian
Published: April 2014

The article explores how youngMozambican women's migratory trajectories towardsEurope are shaped by sexual relationships with older white men and obligations towards female kin. Triads of exchange between young women known ascurtidoras(women enjoying life) and their partners and kin inMaputo are understood through theories of patronage and exchange moralities. Searching for respect, adventure, and consumption in the sexual economy, young women at the same time struggle to ensure their families' well‐being by redistributing the money they extract from white men. Sexual‐monetary transactions, love, and desire must be understood as part of broader moralities of exchange in which migration toEurope and sending of remittances is also a kinship project. The forms of patronage available inMaputo's sexual economy become stepping stones as well as obstacles to migration northwards.