bluuebunny/crossref_metadata_2025 huggingface dataset:
Experimental Evolutionin vivoto Identify Selective Pressures During Pneumococcal Colonization
Authors: Cooper Vaughn S. , Honsa Erin , Rowe Hannah , Deitrick Christopher , Iverson Amy R. , Whittall Jonathan J. , Neville Stephanie L. , McDevitt Christopher A. , Kietzman Colin , Rosch Jason W.
Published: January 2020

Experimental evolution is a powerful technique to understand how populations evolve from selective pressures imparted by the surrounding environment. With the advancement of whole-population genomic sequencing it is possible to identify and track multiple contending genotypes associated with adaptations to specific selective pressures. This approach has been used repeatedly with model speciesin vitro, but only rarelyin vivo. Herein we report results of replicate experimentally evolved populations ofStreptococcus pneumoniaepropagated by repeated murine nasal colonization with the aim of identifying gene products under strong selection as well as the population-genetic dynamics of infection cycles. Frameshift mutations in one gene,dltB, responsible for incorporation of D-alanine into teichoic acids on the bacterial surface, evolved repeatedly and swept to high frequency. Targeted deletions ofdltBproduced a fitness advantage during initial nasal colonization coupled with a corresponding fitness disadvantage in the lungs during pulmonary infection. The underlying mechanism behind the fitness tradeoff between these two niches was found to be enhanced adherence to respiratory cells balanced by increased sensitivity to host-derived antimicrobial peptides, a finding recapitulated in the murine model. Additional mutations were also selected that are predicted to affect trace metal transport, central metabolism and regulation of biofilm production and competence. These data indicate that experimental evolution can be applied to murine models of pathogenesis to gain insight into organism-specific tissue tropisms.

Importance

Evolution is a powerful force that can be experimentally harnessed to gain insight into how populations evolve in response to selective pressures. Herein we tested the applicability of experimental evolutionary approaches to gain insight into how the major human pathogenStreptococcus pneumoniaeresponds to repeated colonization events using a murine model. These studies revealed the population dynamics of repeated colonization events and demonstrated thatin vivoexperimental evolution resulted in highly reproducible trajectories that reflect the environmental niche encountered during nasal colonization. Mutations impacting the surface charge of the bacteria were repeatedly selected during colonization and provided a fitness benefit in this niche that was counterbalanced by a corresponding fitness defect during lung infection. These data indicate that experimental evolution can be applied to models of pathogenesis to gain insight into organism-specific tissue tropisms.
Gatekeeper helix activates Golgi SM protein Sly1 and directly mediates close-range vesicle tethering
Authors: Duan M. , Plemel R.L. , Takenaka T. , Lin A. , Delgado B.M. , Nattermann U. , Nickerson D.P. , Mima J. , Miller E.A. , Merz A.J.
Published: January 2020

The essential Golgi protein Sly1 is a member of the SM (Sec1/mammalian Unc-18) family of SNARE chaperones. Sly1 was originally identified through gain-of-function alleles that bypass requirements for diverse vesicle tethering factors. Employing genetic analyses and chemically defined reconstitutions of ER-Golgi fusion, we discovered that a loop conserved among Sly1 family members is not only autoinhibitory, but also acts as a positive effector. An amphipathic helix within the loop directly binds high-curvature membranes; membrane binding is required for relief of Sly1 autoinhibition and allows Sly1 to directly tether incoming vesicles to the Qa-SNARE on the target organelle. TheSLY1-20allele bypasses requirements for diverse tethering factors but loses this functionality if Sly1 membrane binding is impaired. We propose that long-range tethers, including Golgins and multisubunit tethering complexes, hand off vesicles to Sly1, which then tethers at close range to activate SNARE assembly and fusion in the early secretory pathway.
Modular lipid nanoparticle platform technology for siRNA and lipophilic prodrug delivery
Authors: van der Meel Roy , Chen Sam , Zaifman Josh , Kulkarni Jayesh A. , Zhang Xu Ran S. , Tam Ying K. , Bally Marcel B. , Schiffelers Raymond M. , Ciufolini Marco A. , Cullis Pieter R. , Tam Yuen Yi C.
Published: January 2020

Successfully employing therapeutic nucleic acids, such as small interfering RNA (siRNA), requires chemical modifications or the use of nanocarrier technology to prevent their degradation in the circulation and to facilitate intracellular delivery. Lipid nanoparticles (LNP) are among the most advanced nanocarriers culminating in the first siRNA therapeutic’s clinical translation and approval. At the same time, their applicability as modular platform technology due to the interchangeable building blocks and siRNA payload hallmarks one of LNPs’ major advantages. In addition, drug derivatization approaches to synthesize lipophilic small molecule prodrugs enable stable incorporation in LNPs. This provides ample opportunities to develop combination therapies by co-encapsulating multiple therapeutic agents in a single formulation. Here, we describe how the modular LNP platform can be applied for combined gene silencing and chemotherapy to induce additive anti-cancer effects. We show that various lipophilic taxane prodrug derivatives and siRNA against the androgen receptor, a prostate cancer driver, can be efficiently and stably co-encapsulated in LNPs. In addition, we demonstrate that prodrug incorporation does not affect LNPs’ gene silencing ability and that the combination therapy induces additive therapeutic effectsin vitro. Using a double-radiolabeling approach, we quantitively determined the LNPs’ and prodrugs’ pharmacokinetic properties and biodistribution following systemic administration in tumor-bearing mice. Our results indicate that co-encapsulation of siRNA and lipophilic prodrugs into LNPs is an attractive and straightforward approach for combination therapy development.

GRAPHICAL ABSTRACT
The regulation of mammalian maternal-to-embryonic transition by Eukaryotic translation initiation factor 4E
Authors: Li Yan , Huang Xuefeng , Tang Jianan , Ji Xu , Liu Miao , Chang Lu , Liu Jing , Gu Yihua , Shi Changgen , Ni Wuhua , Shi Hui-juan , O’Neill Chris , Jin Xingliang
Published: January 2020

Genetic and inhibitor studies show expression of eukaryotic translation initiation factor 4E (eIF4E) was required for the successful maternal-to-embryonic transition of mouse embryos. eIF4E was in both gametes and in the cytoplasm and pro-nuclei soon after fertilization, and at each stage of early development. Knockout (Eif4e−/−) byPiggyBac (PB) [Act-RFP]transposition caused peri-implantation embryonic lethality due to the failure of embryos to form a pluripotent epiblast. Maternal stores of eIF4E supported development up to the 2-4-cell stage after which new expression occurred from both alleles. Inhibition of the maternally acquired stores of eIF4E (4EGI-1 inhibitor) resulted in a developmental block at the 2-4-cell stage. 4E-BP1 is a hypophosphorylation-dependent negative regulator of eIF4E. mTOR activity was required for 4E-BP1 phosphorylation and inhibiting 4EGI-1 retarded embryo development. eIF4E expression and activity is regulated at key embryonic transitions in the mammalian embryo and is essential for successful transition to embryonic control of development.

Significance Statement

eIF4E is recognized as the rate-limiting factor for CAP-dependent translation. This work used a combination of a gene knockout model, selective pharmacological inhibition and expression analyses to investigate the expression and function of Eif4e in the early mouse embryo. It provides compelling evidence for the essential role of Eif4E in the normal processes of early mammalian embryo development, including the formation of the pluripotent epiblast and the maternal-embryonic transition. The unexpected evidence for a growth deficit in mice hypomorphic for Eif4e will be a key area of future investigation. It also provides for the first time a powerful demonstration of the utility of thePB [Act-RFP]transposon mouse model for analyzing the molecular regulation of early mammalian embryo development.
Regeneration in the adultDrosophilabrain
Authors: Crocker Kassi L. , Marischuk Khailee , Rimkus Stacey A. , Zhou Hong , Yin Jerry C.P. , Boekhoff-Falk Grace
Published: January 2020

Neurodegenerative diseases such as Alzheimer’s and Parkinson’s currently affect ∼25 million people worldwide (Erkkinenet al. 2018). The global incidence of traumatic brain injury (TBI) is estimated at ∼70 million/year (Dewanet al. 2018). Both neurodegenerative diseases and TBI remain without effective treatments. We are utilizing adultDrosophila melanogasterto investigate the mechanisms of brain regeneration with the long term goal of identifying targets for neural regenerative therapies. Like mammals, Drosophila have few proliferating cells in the adult brain. Nonetheless, within 24 hours of a Penetrating Traumatic Brain Injury (PTBI) to the central brain, there is a significant increase in the number of proliferating cells. We subsequently detect both new glia and new neurons and the formation of new axon tracts that target appropriate brain regions. Glial cells divide rapidly upon injury to give rise to new glial cells. Other cells near the injury site upregulate neural progenitor genes includingasenseanddeadpanand later give rise to the new neurons. Locomotor abnormalities observed after PTBI are reversed within two weeks of injury, supporting the idea that there is functional recovery. Together, these data indicate that adultDrosophilabrains are capable of neuronal repair. We anticipate that this paradigm will facilitate the dissection of the mechanisms of neural regeneration and that these processes will be relevant to human brain repair.
Core Role of TRPC6 Channels in Regulating Airway Re-modelling in Chronic Obstructive Pulmonary Disease
Authors: Zhao Kun , Xie Raoying , Wei Jie , Gu Wenyue , Fei Zhenghua
Published: January 2020

Withdrawal Statement

This manuscript has been withdrawn by the authors as they did not obtain patient consent for the tissue samples use in this study and were, therefore, not able to be approved by the Institute’s Ethics Committee of Wenzhou Medical University. The authors also declare that there are interest conflict about authorship. Therefore, the authors do not wish this work to be cited as reference for the project. If you have any questions, please contact the corresponding author.
Computational modelling of cambium activity provides a regulatory framework for simulating radial plant growth
Authors: Lebovka Ivan , Mele Bruno Hay , Liu Xiaomin , Zakieva Alexandra , Schlamp Theresa , Gursanscky Nial , Merks Roeland M.H. , Großeholz Ruth , Greb Thomas
Published: January 2020

Precise organization of growing structures is a fundamental process in developmental biology. In plants, radial growth is mediated by the cambium, a stem cell niche continuously producing wood (xylem) and bast (phloem) in a strictly bidirectional manner. While this process contributes large parts to terrestrial biomass, cambium dynamics eludes direct experimental access due to obstacles in live cell imaging. Here, we present a cell-based computational model visualizing cambium activity and integrating the function of central cambium regulators. Performing iterative comparisons of plant and model anatomies, we conclude that the receptor- like kinase PXY and its ligand CLE41 are part of a minimal framework sufficient for instructing tissue organization. By integrating tissue-specific cell wall stability values, we moreover probe the influence of physical constraints on tissue geometry. Our model highlights the role of intercellular communication within the cambium and shows that a limited number of factors is sufficient to create radial growth by bidirectional tissue production.

Impact statement

Radial plant growth produces large parts of terrestrial biomass and can be computationally simulated with the help of an instructive framework of intercellular communication loops.
Enterobactersp. SA187 mediates plant thermotolerance by chromatin modification of heat stress genes
Authors: Shekhawat Kirti , Sheikh Arsheed , Mariappan Kiruthiga , Jalal Rewaa , Hirt Heribert
Published: January 2020

Global warming has become a critical challenge to food safety, causing severe yield losses of major crops worldwide. Heat acclimation empowers plants to survive under extreme temperature conditions but the potential of beneficial microbes to make plants thermotolerant has not been considered so far. Here, we report that the endophytic bacteriumEnterobactersp. SA187 induces heat tolerance inArabidopsis thalianaby reprogramming the plant transcriptome to a similar extent as acclimation. Acclimation induces priming of heat stress memory genes such asAPX2andHSP18.2via the transcription factorsHSFA1A, B, D, and Eand the downstream master regulatorHSFA2. hsfa1a,b,d,eandhsfa2mutants compromised both acclimation and bacterial priming through the same pathway ofHSFtranscription factors. However, while acclimation transiently modifies H3K4me3 levels at heat stress memory gene loci, SA187 induces the constitutive priming of these loci. In summary, we demonstrate the molecular mechanism by which SA187 imparts thermotolerance inA. thaliana, suggesting that beneficial microbes might be a promising way to enhance crop production under global warming conditions.
Spatio-temporal patterns of wildfires in the Niassa Reserve –Mozambique, using remote sensing data
Authors: Nhongo Eufrásio , Fontana Denise , Guasselli Laurindo
Published: January 2020

Wildfires are among the biggest factors of ecosystem change. Knowledge of fire regime (fire frequency, severity, intensity, seasonality, and distribution pattern) is an important factor in wildfire management. This paper aims to analyze the spatiotemporal patterns of fires and burned areas in the Niassa Reserve between 2002-2015 using MODIS data, active fire product (MCD14ML) and burned area product (MCD64A1). For this, the annual and monthly frequencies, the trend of fires and the frequency by types of forest cover were statistically analyzed. For the analysis of the spatial dynamics of forest fires we used the Kernel density (Fixed Method). The results show a total of 20.449 forest fires and 171.067 km2of burned areas in the period 2002-2015. Fire incidents were highest in 2015, while the largest burned areas were recorded in 2007. The relationship between increased fires and burned areas is not linear. There was a tendency for fires to increase, while for burnt areas there was stabilization. Forest fires start in May and end in December. August-October are the most frequent period, peaking in September. Fires occur predominantly in deciduous forests and mountain forests because of the type of vegetation and the amount of dry biomass. There is a monthly spatial dynamics of wildfires from east to west in the reserve. This behavior is dependent on vegetation cover type, fuel availability, and senescence.
Optimized single molecule fluorescence sheds light on elusive enzymatic mechanisms
Authors: Usaj Marko , Moretto Luisa , Vemula Venukumar , Salhotra Aseem , Månsson Alf
Published: January 2020

Single molecule enzymology using fluorescent substrate requires truly minimal amounts of proteins. This is highly beneficial when the protein source is either advanced expression systems or samples from humans/animals with ethical and economic implications. Further benefits of single molecule analysis is the potential to reveal phenomena hidden in ensemble studies. However, dye photophysics and fluorescent contaminants complicate interpretation of the single molecule data. We here corroborate the importance of such complexities using fluorescent Alexa647 ATP to study ATP turnover by myosin and actomyosin. We further show that the complexities are largely eliminated by aggressive surface cleaning and use of a range of triple state quenchers and redox agents with minor effects on actin-myosin function. Using optimized assay conditions, we then show that the distributions of ATP binding dwell times on myosin are best described by the sum of 2 to 3 exponential processes. This applies in the presence and absence of actin and in the presence and absence of the drug para-aminoblebbistatin. Two of the processes are attributable to ATP turnover by myosin and actomyosin, respectively. A remaining process with rate constant in the range 0.2-0.5 s-1is consistent with non-specific ATP binding to myosin and bioinformatics modelling suggests that such binding may be important for accelerated ATP transport to the active site. Finally, we report studies of the actin-activated myosin ATP turnover under conditions with no sliding between actin and myosin, as in isometrically contracting muscle, revealing heterogeneity in the ATP turnover kinetics between different molecules.
Structure of the XylanO-Acetyltransferase AtXOAT1 Reveals Molecular Insight into Polysaccharide Acetylation in Plants
Authors: Lunin Vladimir V. , Wang Hsin-Tzu , Bharadwaj Vivek S. , Alahuhta Markus , Peña Maria J. , Yang Jeong-Yeh , Archer-Hartmann Stephanie A. , Azadi Parastoo , Himmel Michael E. , Moremen Kelley W. , York William S. , Bomble Yannick J. , Urbanowicz Breeanna R.
Published: January 2020

Acetylation of biomolecules is gaining increased attention due to both the abundance and importance of this modification across all kingdoms of life. Xylans are a major component of plant cell walls and are the third most abundant biopolymer in Nature.O-Acetyl moieties are the dominant backbone substituents of glucuronoxylan in dicots and play a major role in the polymer-polymer interactions that are crucial for proper wall architecture and normal plant development. Here, we describe the biochemical, structural, and mechanistic characterization of Arabidopsis thaliana xylan O-acetyltransferase 1 (AtXOAT1), a member of the plant-specific Trichome Birefrigence Like (TBL) family that catalyzes the 2-O-acetylation of xylan. A multipronged approach involving X-ray crystallography, biochemical analyses, mutagenesis, and molecular simulations show that XOAT1 catalyzes xylan acetylation through formation of an acyl-enzyme intermediate by a double displacement bi-bi mechanism involving a Ser-His-Asp catalytic triad and unconventionally employs an arginine residue in formation of an oxyanion hole.
Transcytosis via the late endocytic pathway as a cell morphogenetic mechanism
Authors: Mathew R , Rios-Barrera LD , Machado P , Schwab Y , Leptin M
Published: January 2020

Plasma membranes fulfil many physiological functions. In polarized cells, different membrane compartments take on specialized roles, each being allocated correct amounts of membrane. The Drosophila tracheal system, an established tubulogenesis model, contains branched terminal cells with subcellular tubes formed by apical plasma membrane invagination. We show that apical endocytosis and late endosome-mediated trafficking determine the membrane allocation to the apical and basal membrane domains. Basal plasma membrane growth stops if endocytosis is blocked, whereas the apical membrane grows excessively. Plasma membrane is initially delivered apically, and then continuously endocytosed, together with apical and basal cargo. We describe an organelle carrying markers of late endosomes and multivesicular bodies (MVBs) that is abolished by inhibiting endocytosis, and which we suggest acts as transit station for membrane destined to be redistributed both apically and basally. This is based on the observation that disrupting MVB formation prevents growth of both compartments.
Dissecting the nanoscale lipid profile of caveolae
Authors: Zhou Yong , Ariotti Nicholas , Rae James , Liang Hong , Tillu Vikas , Tee Shern , Bastiani Michele , Bademosi Adekunle T. , Collins Brett M. , Meunier Frederic A. , Hancock John F. , Parton Robert G.
Published: January 2020

Caveolae are specialized domains of the vertebrate cell surface with a well-defined morphology and crucial roles in cell migration and mechanoprotection. Unique compositions of proteins and lipids determine membrane architectures. The precise caveolar lipid profile and the roles of the major caveolar structural proteins, caveolins and cavins, in selectively sorting lipids have not been defined. Here we used quantitative nanoscale lipid mapping together with molecular dynamic simulations to define the caveolar lipid profile. We show that caveolin1 (CAV1) and cavin1 individually sort distinct plasma membrane lipids. Intact caveolar structures composed of both CAV1 and cavin1 further generate a unique lipid nano-environment. The caveolar lipid sorting capability includes selectivities for lipid headgroups and acyl chains. Because lipid headgroup metabolism and acyl chain remodelling are tightly regulated, this selective lipid sorting may allow caveolae to act as transit hubs to direct communications among lipid metabolism, vesicular trafficking and signalling.
Crystal structure of strontium thiosulfate monohydrate
Authors: Klein Wilhelm
Published: January 2020

SrS2O3·H2O was obtained from an aqueous solution of Na2S2O3 and Sr(NO3)2 and crystallizes in space group P\overline{1} with all atoms at general positions. The Sr2+ ion exhibits an [8 + 1] coordination defined by two terminal S and six O atoms of thiosulfate ions, one of the latter at a longer distance, and by one O atom of a water molecule. Two thiosulfate anions act as bidentate, four as monodentate ligands. The structure consists of mainly ionically interacting layers lying parallel to the crystallographic ab plane. The layers are connected by O—H...S and O—H...O hydrogen bonds of moderate strength.
Preparation of complex surface coatings based on electrospark computer integrated deposition system
Authors: Wang X.R. , Wang Z.Q. , Lin T.S. , He P. , Wang R.J. , Bao M.Y.
Published: January 2020

Purpose

Electrospark deposition (ESD) attracts special attention from scientists and engineers because of its unique advantages. However, the ESD process has been carried out by hand up to the present. This prevents ESD from preparing complex curve/surface coatings owing to manual operation characteristics. To meet the coating precise preparation requirements for a lot of parts with complex surface from various industrial fields, this paper aims to obtain a new automatic ESD equipment, process and preparation methodology for complex surface coatings.

Design/methodology/approach

By designing a special deposition holder and re-programming programmable machine controller, an ESD power supply and a computer numerical control milling machine are integrated to obtain an electrospark-computer integrated deposition system (ES-CIDS). Then, based on the ES-CIDS, a new ESD process, named electrospark-computer numerical control deposition (ES-CNCD) is developed. Furthermore, complex surface coatings are depicted using non-uniform rational B-spline mathematical model and modeled in a special software developed via MATLAB. Finally, deposition programs for a complex coating are generated using golden section interpolation method, and transferred to and executed by the ES-CIDS to accomplish the preparation of the complex surface coating.

Findings

This paper demonstrates that it is possible and feasible to prepare complex surface coatings via an automatic ESD process (namely, ES-CNCD) precisely.

Research limitations/implications

This paper can make automatic ESD process get more attention from scientific researchers and engineers, and promote the research of the ES-CNCD process/equipment.

Practical implications

The ES-CNCD process can be used in the manufacturing of complex surface coatings, and in the remanufacturing of complex shape parts.

Social implications

The ES-CIDS/ES-CNCD can promote the development of related equipment and technology, and bring opportunities and employment to ESD industry.

Originality/value

This work prepares complex surface coatings precisely for the first time using a new automatic ESD process (ES-CNCD), which has wide application prospects in various industries.
A lean production system design for semiconductor crystal-ingot pulling manufacturing using hybrid Taguchi method and simulation optimization
Authors: Yang Taho , Wen Yuan-Feng , Hsieh Zong-Rui , Zhang Jianxia
Published: January 2020

Purpose

The purpose of this study is to propose an innovative methodology in solving the lean production design from semiconductor crystal-ingot pulling manufacturing which is an important industry. Due to the complexity of the system, it is computationally prohibited by an analytical approach; thus, simulation optimization is adopted for this study.

Design/methodology/approach

Four control factors that affect the system’s performance, including the pulling strategy, machine limitations, dispatching rules and batch-size control, are identified to generate the future-state value stream mapping. Taguchi two-step procedure and simulation optimization are used to determine the optimal parameter values for a robust system.

Findings

The proposed methodology improved the system performances by 6.42 and 12.02 per cent for service level and throughput, respectively.

Research limitations/implications

This study does not investigate operations management issues such as setup reduction, demand forecasting and layout design.

Practical implications

A real-world crystal-ingot pulling manufacturing factory was used for the case study. The results are promising and are readily applied to other industrial applications.

Social implications

The improved performances, service level and throughout rate, can result in an improved customer satisfaction level and a reduced resources consumption, respectively.

Originality/value

The proposed methodology innovatively solved a practical application and the results are promising.
Operational and relational governances of buyer–supplier exchanges
Authors: Yang Jie , Xie Hongming , Yu Guangsheng , Liu Mingyu , Yang Yingnan
Published: January 2020

Purpose

This study examines the operational and relational governances as antecedents of cooperation commitment in buyer–supplier exchanges. It also assesses the impact of cooperation commitment on operational performance.

Design/methodology/approach

Path analysis was performed on the data collected from manufacturers.

Findings

The results of this study show that both operational and relational governances exert impact on cooperation commitment, which, in turn, is associated with operational performance improvement.

Originality/value

First, this is the first study employing the reciprocity theory to theorize the conceptual framework of the governance antecedents of cooperation commitment and operations excellence effect. Second, the study highlights how the research framework can enrich the reciprocity theory in exploring the mechanisms of the operational and relational governances of buyer–supplier exchanges and their impact on the commitment to the cooperation. Third, this study extends the reciprocity theory to examine in detail how cooperation commitment exerts impact on the operational performance.
Controlling superprojects – information management requirements
Authors: Parnell Brett , Stone Merlin , Aravopoulou Eleni
Published: January 2020

Purpose

This paper aims to explore the problems of managing superprojects and identifies how a different approach to controlling them can reduce the incidence of cost and time overruns and benefit shortfalls.

Design/methodology/approach

Literature review accompanied by conceptual analysis.

Findings

Project cost and timing overruns and benefit shortfalls are very frequent in superprojects. These problems can be ascribed partly to the way in which they are planned is not taken into account in designing and implementing control systems, particularly the governance processes and the information they have available.

Practical implications

This paper has serious implications for those designing control processes, governance and information management for superprojects. It suggests that if a new approach is taken, fewer superprojects will suffer from cost overruns and benefit shortfalls because remedial actions will be taken earlier for projects, which are experiencing problems, while learning will be fed back to those planning new projects.

Social implications

There will be saving of public money and reduced deferment of benefits that normally result from failed or delayed projects and reduced allocation of large incremental budgets dedicated to resolving problems.

Originality/value

The taxonomy of different types of superprojects is original, as is the idea of ambidextrous control, and the diagnosis of failure reasons lying in the nature of control and governance processes, and the lack of relevant information available during the control process.
Types of director, board diversity and firm performance
Authors: Fernández-Temprano Miguel A. , Tejerina-Gaite Fernando
Published: January 2020

Purpose

The purpose of this paper is to investigate the effect of board diversity on firm performance.

Design/methodology/approach

From different theories perspective and based on data collected about the composition of board of directors in Spanish non-financial firms, the paper determines statistically the relationship between board diversity and performance for the period 2005-2015.

Findings

The results reveal differences between inside and outside board members in terms of the performance impact of board diversity. Thus, while age diversity has a positive effect on firm performance in both, insider and outsider directors, nationality mix is associated with higher performance levels just in the case of insiders. In addition, educational diversity seems to have a negative effect on performance for supervisory directors. On the contrary, the authors do not find any evidence about a possible influence of gender diversity on performance.

Research limitations/implications

The authors are just taking some board’s attributes, but the concept of board diversity is a very wide one. In this regard, less traditional methodologies that do not rely on extant archival databases may be necessary to get a deeper understanding of the impact of boards on firm’s performance.

Practical implications

This study demonstrates that the claim of “one size fits all” often implicitly stated by regulators and advisors is misleading. Board’s attributes analysis over the boardroom as a whole turns out in too simplistic conclusions. This is particularly important for regulators: a rigorous analysis should be performed before including general recommendations about, for instance, the age or the board tenure in corporate governance codes.

Social implications

As diverse boards contribute to a greater social value, the paper analyses the performance consequences of demographic diversity.

Originality/value

The paper analyses the firm performance impact of diversity among insider directors, on the one hand, and outsider directors, on the other. Although there is a clear difference between the roles assigned to insider and outsider directors, to the authors’ knowledge, there has been no analysis of the firm performance effect of the diversity of each type of director using the same sample and methodology.
Comparison of simplified techniques for solving selected coupled electroheat problems
Authors: Pánek David , Karban Pavel , Orosz Tamás , Doležel Ivo
Published: January 2020

Purpose

The purpose of this paper is to compare different reduced-order models for models of control of induction brazing process. In the presented application, the problem is to reconstruct temperature at the points of interests (hot spots) from information measured at accessible places.

Design/methodology/approach

The paper describes the process of induction brazing. It presents the full field model and evaluates the possibilities for obtaining reduced models for temperature estimation. The primary attention is paid to the model based on proper orthogonal decomposition (POD).

Findings

The paper shows that for the given application, it is possible to find low-order estimator. In the examined linear case, the best estimator was created using POD reduced model together with the linear Kalman filter.

Research limitations/implications

The authors are aware of two main limitations of the presented study: material properties are considered linear, which is not a completely realistic assumption. However, if strong coupling and nonlinear material parameters are considered, the model becomes unsolvable. The process and measurement uncertainties are not considered.

Originality/value

The paper deals with POD of multi-physics 3 D application of induction brazing. The paper compares 11 different methods for temperature estimator design.
The construction and regulation of collective entrepreneurial identity in student entrepreneurship societies
Authors: Siivonen Päivi Tuulikki , Peura Kirsi , Hytti Ulla , Kasanen Kati , Komulainen Katri
Published: January 2020

Purpose

The purpose of this paper is to critically investigate how collective identity is constructed and regulated by board members and other active members of student entrepreneurship societies (ESs).

Design/methodology/approach

A discursive analysis focusing on collective identity construction and regulation based on focus group discussions in two student-led Finnish ESs affiliated with higher education institutions (HEIs).

Findings

ES members construct and regulate collective entrepreneurial identity based on a shared narrative of entrepreneurship and the affective state of positive energy and thinking, i.e. “positive buzz.” Being entrepreneurial was constructed as having the right kind of mentality to cope with uncertain and rapidly changing working life and to break free of old moulds of working. The shared narrative was coherent, and critical reflection on the values or risks of entrepreneurship was mainly silenced.

Research limitations/implications

As ESs are a relatively new phenomenon future research could explore ESs in different cultural and regional contexts and compare the identity construction and regulation of ES student members and non-members.

Practical implications

Strong collective identity and sense of commitment to doing things together may mitigate the pressures of being entrepreneurial and taking charge of one’s life.

Social implications

Educational practice and research could benefit from better understanding of the informal context in which entrepreneurship education takes place.

Originality/value

The paper contributes to the relatively new research stream on ESs as student-led entrepreneurial organizations in HEIs. The research demonstrates how ES members participate in constructing a collective and coherent identity that is regulated by shared values and a positive state of mind. This study extends the understanding of ESs from the functional perspective to viewing them as a social community. It contributes to the definition of ESs and the self-understanding of ES actors.
Racial/ethnic and national origin bias in SET
Authors: Wang Lei , Gonzalez Jorge A.
Published: January 2020

Purpose

This study aims to test the presence of an adverse impact against professors belonging to minority groups (African American, Asian American, Hispanic American and foreign national origin) in official student evaluation of teaching (SET).

Design/methodology/approach

The authors conducted a series of regression analyses to compare SET rating sources and control for course difficulty.

Findings

The regression analysis results showed that White American professors receive higher SET ratings than non-White American and foreign professors, which implies the presence of bias in SET.

Originality/value

To the authors’ knowledge, this is the first study to examine race/ethnicity and national origin bias in SET using official SET results from multiple universities.
Unpacking the predictive effects of social characteristics on job crafting
Authors: Li Xiaojun , Takao Yoshiaki
Published: January 2020

Purpose

The purpose of this study is to examine the predictive effects of social context and its interaction effects with individual differences on job crafting behaviors. Specially, this paper draws on the purposeful work behavior theory to outline how the four social characteristics (social support, interdependence, interaction outside the organization and feedback from others) and the moderation effects of neuroticism predict task crafting, relational crafting and cognitive crafting.

Design/methodology/approach

The current study examined four social characteristics as antecedents of job crafting behaviors. The moderating effects of neuroticism were explored as well. By conducting a three-wave survey, the authors received a sample of 253 full-time incumbents in Japan. The data analysis used multiple regressions by using R language. Correlational and moderated regression analyses were performed to test this study’s hypotheses.

Findings

Empirical analysis of this study’s data shows some initial support for the application of the purposeful work behaviors theory to job crafting. The findings indicate that all four social characteristics promoted particular job crafting behaviors. Neuroticism was a significant moderator for the relationships between social support, interaction outside the organization, feedback from others and relative job crafting dimensions. The current study extends existing models of job crafting.

Originality/value

The current study makes significant theoretical contributions for both work design and job crafting literature. The present framework enriches our understanding of job crafting by demonstrating a picture of a moderated model between social characteristics and job crafting by uncovering the moderator – neuroticism. This study’s findings also contribute to managerial practices. Managers should build a supportive context and provide interdependence, interactions outside the organization and interpersonal performance feedback. To motivate employees with different personalities, offering different social context is necessary.
Leader–member exchange in public organizations: a qualitative study
Authors: Salehzadeh Reza
Published: January 2020

Purpose

The purpose of this paper is to propose the new typologies of leader–member exchange (LMX) theory.

Design/methodology/approach

This research conducted a thorough, targeted literature review along with a qualitative research method involving in-depth, open-ended and semi-structured interviews. The interviews were conducted with 21 managers and 70 employees of different public organizations during the two years. After interviews, data were transcribed and the qualitative research method of theory elaboration was used to extract the themes from the transcripts.

Findings

The results showed that the LMX has a dynamic nature with four different versions. Also, the results discovered the multi-level of LMX with three different types of leaders’ styles. In addition, four factors that cause damage to high-quality relationships have been identified (i.e. perceived dissimilarity, feeling of being betrayed, failure to meet the expectations and impression management). Finally, the results discovered five dark sides of LMX.

Originality/value

This research proposes the new typologies of LMX and the approach and findings of this research contribute to the literature of leadership theories.
Determinants of public sector accounting reforms
Authors: De Silva Lokuwaduge Chitra Sriyani , De Silva Keshara
Published: January 2020

Purpose

The purpose of this paper is to extend the New Public Financial Management concept and the contingency model approach to an analysis of the determinants of the accrual-based International Public Sector Accounting Standards (IPSAS) adoption process as a financial management reform in Sri Lanka, a developing country in Asia.

Design/methodology/approach

Based on the prior literature, this paper develops a framework to highlight the importance of accrual-based reforms in public sector accounting policies to enable better transparency and accountability. It shows the extent to which Sri Lankan public sector institutions have adopted IPSAS-based accounting standards and the limitations of adopting these standards in a developing country, using documentary analysis.

Findings

In developing countries, the public sector faces practical problems when adopting reforms due to limited institutional capacity, high political involvement and bureaucracy in decision making. This paper concludes that significant policy changes towards the adoption of international accounting standards have gained momentum over the last decade in Sri Lanka while the much larger economies in Asia are still studying this process. However, the prevailing political uncertainty in Sri Lanka has negatively impacted the implementation process.

Originality/value

Relatively little is known about the diffusion of, and the difficulties in, implementing accrual-based IPSAS in the Asian region. This paper is an attempt to fill this gap by exploring the Sri Lankan experience. This could be applied by other developing countries in Asia, including the high-growth nations, for policy adoption and accounting harmonisation.
Budgetary bias in the Finnish public hospital system
Authors: Karila Alpo , Vakkuri Jarmo , Lehto Juhani
Published: January 2020

Purpose

The purpose of this paper is to analyze the dynamics of budgetary biasing in the context of public hospitals.

Design/methodology/approach

The study applies theories of accounting and budgeting behaviors in the specific institutional context of health care systems. Based on the theoretical framework, data from interviews with hospital budget officers were analyzed using qualitative content analysis.

Findings

A typology of biases is provided. It proved to be useful and highlighted the central empirical assumptions and preliminary results of biasing dynamics.

Practical implications

Understanding the logic of budgeting actors and the drivers of bias may help explain why bias so often appears in health care budgeting. It further contributes to understanding whether the bias is functional or dysfunctional.

Originality/value

The concepts of budgetary bias are rarely used in the context of health care budgeting, so the study fills a gap in research knowledge.
The role of informal competition in driving export propensity of emerging economy firms
Authors: Deb Rouhin , Samalia Harsh Vardhan , Prusty Santosh Kumar
Published: January 2020

Purpose

Competitive pressure from informal firms has always been a threat to the formal enterprises. However, the strategic choices a firm makes to deal with such competitive pressures still remain under-explored. The purpose of this paper is to examine the influence of informal competitive pressures in driving export propensity of formal firms.

Design/methodology/approach

The paper is based on a standard error logistic model, and the model takes into account the contingent relationships along with the primary relationship. The authors draw the sample of 9,812 manufacturing firms spanning across the Indian sub-continent from the World Bank enterprise survey conducted in the year 2014.

Findings

The empirical results indicated that the level of competition from informal firms is positively associated with the propensity to export. The primary relationship is also affected by various contingent factors such as regulatory obstacles, bribery and new product development.

Research limitations/implications

Although the World Bank enterprise survey data provide a broad coverage, the study warranted few proxy measures in order to operationalize formal competition as it was not captured directly in the concerned data set.

Practical implications

The analysis demonstrates that informal competition has direct effect on the firm’s propensity to export. The findings indicate that export is an attractive action alternative for firms facing informal completion in an emerging economy. The results further indicate that this effect strengthens as institutional factors such as regulatory obstacles and bribery increase.

Social implications

The paper is an attempt to alter the prevailing negative view on informality. The findings indicate that informal competition spurs competitiveness in the formal sector indicating its positive role in the economic growth of the nation.

Originality/value

The paper takes cue from attention-based view of the firm and the institutional escapism logic to affirm the role of informal competition and various contingent institutional and strategic factors in driving export propensity.
Enhancing consumer trust in short food supply chains
Authors: Ji Chen , Chen Qin , Zhuo Ni
Published: January 2020

Purpose

The purpose of this paper is to explore how consumers’ trust is enhanced by e-commerce-based agribusiness companies. It also aims to shed light on the role of social commerce in improving consumers’ trust.

Design/methodology/approach

To achieve the research purpose, an in-depth multiple case study is performed. In this study, three cases in short food supply chain (SFSC) in China are selected, and they are all e-commerce agribusiness companies. They adopted common ways to build up, maintain and reinforce consumers’ trust.

Findings

It is revealed that the companies innovatively adopted social commerce, both online and offline, to overcome the trust problems usually faced by e-commerce companies. It is also shown that offline contact with potential consumers is an important first step for agribusiness e-commerce entrepreneurs to build up trust with consumers.

Research limitations/implications

By adopting a multiple case study method, the research has limited generalizability to other types of SFSCs. Since the findings are from Chinese agribusiness e-commerce companies, the generalization to other sectors must be done with caution.

Practical implications

Some managerial implications are given as follows: first, offline contact with consumers could be realized through different channels. Taking advantage of existing social network or trying to find consumers in urban communities might be effective ways. Second, trust building with consumers is not an easy task, managers need to emphasize trust building, trust maintaining, as well as trust reinforcing with consumers. In agri-food sector, managers might need to specifically address the importance of food safety and quality so as to not lose consumer trust in one night.

Originality/value

The study has mainly two contributions: first, it has managerial implications for agribusiness e-commerce entrepreneurs, addressing the important role of social presence in building up consumer trust. Second, it contributes to social presence and social relations literature by providing new empirical evidence from e-commerce in agri-food sector and in developing countries.