bluuebunny/crossref_metadata_2025 huggingface dataset:
Seasonal and ontogenetic variation of skin microbial communities and relationships to natural disease dynamics in declining amphibians
Authors: Longo Ana V. , Savage Anna E. , Hewson Ian , Zamudio Kelly R.
Published: July 2015

Recently, microbiologists have focused on characterizing the probiotic role of skin bacteria for amphibians threatened by the fungal disease chytridiomycosis. However, the specific characteristics of microbial diversity required to maintain health or trigger disease are still not well understood in natural populations. We hypothesized that seasonal and developmental transitions affecting susceptibility to chytridiomycosis could also alter the stability of microbial assemblages. To test our hypothesis, we examined patterns of skin bacterial diversity in two species of declining amphibians (
Lithobates yavapaiensis
and
Eleutherodactylus coqui
) affected by the pathogenic fungus
Batrachochytrium dendrobatidis
(
Bd
). We focused on two important transitions that affect
Bd
susceptibility: ontogenetic (from juvenile to adult) shifts in
E. coqui
and seasonal (from summer to winter) shifts in 
L. yavapaiensis
. We used a combination of community-fingerprinting analyses and 16S rRNA amplicon sequencing to quantify changes in bacterial diversity and assemblage composition between seasons and developmental stages, and to investigate the relationship between bacterial diversity and pathogen load. We found that winter-sampled frogs and juveniles, two states associated with increased
Bd
susceptibility, exhibited higher diversity compared with summer-sampled frogs and adult individuals. Our findings also revealed that hosts harbouring higher bacterial diversity carried lower
Bd
infections, providing support for the protective role of bacterial communities. Ongoing work to understand skin microbiome resilience after pathogen disturbance has the potential to identify key taxa involved in disease resistance.
Sexual reproduction with variable mating systems can resist asexuality in a rock–paper–scissors dynamics
Authors: Carranza Juan , Polo Vicente
Published: July 2015

While sex can be advantageous for a lineage in the long term, we still lack an explanation for its maintenance with the twofold cost per generation. Here we model an infinite diploid population where two autosomal loci determine, respectively, the reproductive mode, sexual versus asexual and the mating system, polygynous (costly sex) versus monogamous (assuming equal contribution of parents to offspring, i.e. non-costly sex). We show that alleles for costly sex can spread when non-costly sexual modes buffer the interaction between asexual and costly sexual strategies, even without twofold benefit of recombination with respect to asexuality. The three interacting strategies have intransitive fitness relationships leading to a rock–paper–scissors dynamics, so that alleles for costly sex cannot be eliminated by asexuals in most situations throughout the parameter space. Our results indicate that sexual lineages with variable mating systems can resist the invasion of asexuals and allow for long-term effects to accumulate, thus providing a solution to the persisting theoretical question of why sex was not displaced by asexuality along evolution.
Closed-form stochastic solutions for non-equilibrium dynamics and inheritance of cellular components over many cell divisions
Authors: Johnston Iain G. , Jones Nick S.
Published: July 2015

Stochastic dynamics govern many important processes in cellular biology, and an underlying theoretical approach describing these dynamics is desirable to address a wealth of questions in biology and medicine. Mathematical tools exist for treating several important examples of these stochastic processes, most notably gene expression and random partitioning at single-cell divisions or after a steady state has been reached. Comparatively little work exists exploring different and specific ways that repeated cell divisions can lead to stochastic inheritance of unequilibrated cellular populations. Here we introduce a mathematical formalism to describe cellular agents that are subject to random creation, replication and/or degradation, and are inherited according to a range of random dynamics at cell divisions. We obtain closed-form generating functions describing systems at any time after any number of cell divisions for binomial partitioning and divisions provoking a deterministic or random, subtractive or additive change in copy number, and show that these solutions agree exactly with stochastic simulation. We apply this general formalism to several example problems involving the dynamics of mitochondrial DNA during development and organismal lifetimes.
Anti-plane shear waves in periodic elastic composites: band structure and anomalous wave refraction
Authors: Nemat-Nasser Sia
Published: July 2015

For anti-plane shear waves in periodic elastic composites, it is shown thatnegative energy refraction can be accompanied by positive phase-velocity refractionandpositive energy refraction can be accompanied by negative phase-velocity refraction, and that this can happen over a broad range of frequencies. Hence, in general, negative refraction does not necessarily require antiparallel group and phase-velocity vectors. Details are given for layered composites and the results are extended to, and illustrated for, two-dimensional periodic composites, revealing a wealth of information about the refractive characteristics of this class of composites. The composite's unit cell may consist of any number of constituents of anyvariable mass density and elastic modulus, admitting large discontinuities. A powerful variational-based solution method is used that applies to one-, two- and three-dimensional composites, irrespective of their constituents being homogeneous or heterogeneous. The calculations are direct, accurate and efficient, yielding the band structure, group-velocity, energy-flux and phase-velocity vectors as functions of the frequency and wavevector components, over an entire frequency band.
A tale of the ciliate tail: investigation into the adaptive significance of this sub-cellular structure
Authors: Gemmell Brad J. , Jiang Houshuo , Buskey Edward J.
Published: July 2015

Ciliates can form an important link between the microbial loop and higher trophic levels primarily through consumption by copepods. This high predation pressure has resulted in a number of ciliate species developing rapid escape swimming behaviour. Several species of these escaping ciliates also possess a long contractile tail for which the functionality remains unresolved. We use high-speed video, specialized optics and novel fluid visualization tools to evaluate the role of this contractile appendage in two free-swimming ciliates,
Pseudotontonia
sp. and
Tontonia
sp., and compare the performance to escape swimming behaviour of a non-tailed species,
Strobilidium
sp. Here, we show that ‘tailed’ species respond to hydrodynamic disturbances with extremely short response latencies (less than or equal to 0.89 ms) by rapidly contracting the tail which carries the cell body 2–4 cell diameters within a few milliseconds. This provides an advantage over non-tailed species during the critical first 10–30 ms of an escape. Two small, short-lived vortex rings are created during contraction of the tail. The flow imposed by the ciliate jumping can be described as two well-separated impulsive Stokeslets and the overall flow attenuates spatially as
r
−3
. The high initial velocities and spatio-temporal arrangement of vortices created by tail contractions appear to provide a means for rapid escape as well as hydrodynamic ‘camouflage’ against fast striking, mechanoreceptive predators such as copepods.
Social learning in a high-risk environment: incomplete disregard for the ‘minnow that cried pike’ results in culturally transmitted neophobia
Authors: Crane Adam L. , Mathiron Anthony G. E. , Ferrari Maud C. O.
Published: July 2015

Many prey species rely on conspecifics to gather information about unknown predation threats, but little is known about the role of varying environmental conditions on the efficacy of social learning. We examined predator-naive minnows that had the opportunity to learn about predators from experienced models that were raised in either a low- or high-risk environment. There were striking differences in behaviour among models; high-risk models showed a weaker response to the predator cue and became neophobic in response to the control cue (a novel odour, NO). Observers that were previously paired with low-risk models acquired a strong antipredator response only to the predator cue. However, observers that interacted with high-risk models, displayed a much weaker response to the predator odour and a weak neophobic response to the NO. This is the first study reporting such different outcomes of social learning under different environmental conditions, and suggests high-risk environments promote the cultural transmission of neophobia more so than social learning. If such a transfer can be considered similar to secondary traumatization in humans, culturally transmitted neophobia in minnows may provide a good model system for understanding more about the social ecology of fear disorders.
Sinimarinibacterium flocculans gen. nov., sp. nov., a gammaproteobacterium from offshore surface seawater
Authors: Zhang Xin-Qi , Sun Cong , Wang Chun-Sheng , Zhang Xin , Zhou Xiang , Wu Yue-Hong , Xu Xue-Wei , Wu Min
Published: July 2015

Two aerobic, rod-shaped, non-motile, non-sporulating and Gram-staining-negative bacterial strains, namely NH6-24T and Za3-11, were isolated from the surface seawater of the South China Sea and the estuary of the Yangtze River, respectively. The two isolates grew at 14–44 °C (optimum 37–40 °C) and pH 6.0–8.5 (optimum pH 7.0–7.5). The sea salt ranges for growth were 0.5–10 % (w/v) (optimum 1–2.5 %) for strain NH6-24T and 0–12 % (w/v) (optimum 0.5–4.5 %) for strain Za3-11.Both strains could grow in the absence of NaCl. Results of phylogenetic analysis based on 16S rRNA gene sequences indicated that the two isolates showed closest affinity to the genera Fontimonas (96.0 %) and Solimonas (94.1–95.1 %) and formed a single lineage in the cluster of the family Solimonadaceae. The predominant isoprenoid quinone was ubiquinone-8.The major fatty acids were C18 : 1ω7c, iso-C16 : 0 and C16 : 0.The dominant polar lipids were diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine. The DNA G+C content was 65 mol%. Based on the polyphasic taxonomic characterization, strains NH6-24T and Za3-11 are considered to represent a novel species of a novel genus, for which the name Sinimarinibacterium flocculans gen. nov., sp. nov. is proposed. The type strain of the type species is NH6-24T ( = CGMCC 1.10815T = JCM 17607T) and an additional strain is Za3-11 ( = CGMCC 1.10816 = JCM 17606).
Vibrio oceanisediminis sp. nov., a nitrogen-fixing bacterium isolated from an artificial oil-spill marine sediment
Authors: Kang Sang Rim , Srinivasan Sathiyaraj , Lee Sang-Seob
Published: July 2015

A Gram-staining-negative, halophilic, facultatively anaerobic, motile, rod-shaped and nitrogen-fixing bacterium, designated strain S37T, was isolated from an artificial oil-spill sediment sample from the coast of Taean, South Korea. Cells grew at 10–37 °C and pH 5.0–9.0, with optimal growth at 28 °C and pH 6.0–8.0. Growth was observed with 1–9 % (w/v) NaCl in marine broth, with optimal growth with 3–5 % NaCl, but no growth was observed in the absence of NaCl. According to the results of 16S rRNA gene sequence analysis, strain S37T represents a member of the genus Vibrio of the class Gammaproteobacteria and forms a clade with Vibrio plantisponsor MSSRF60T (97.38 %), Vibrio diazotrophicus ATCC 33466T (97.31 %), Vibrio aestuarianus ATCC 35048T (97.07 %) Vibrio areninigrae J74T (96.76 %) and Vibrio hispanicus LMG 13240T (96.76 %). The major fatty acids were C16 : 0, C16 : 1ω7c/C16 : 1ω6c and C18 : 1ω7c/C18 : 1ω6c. The DNA G+C content was 41.9 %. The DNA–DNA hybridization analysis results showed a 30.2 % association value with the closely related type strain V. plantisponsor DSM 21026T. On the basis of phenotypic and chemotaxonomic characteristics, strain S37T represents a novel species of the genus Vibrio, for which the name Vibrio oceanisediminis sp. nov., is proposed with the type strain S37T ( = KEMB 2255-005T = JCM 30409T).
Numerical study on characteristics of unsteady flow in a centrifugal pump volute at partial load condition
Authors: Tan Lei , Zhu Baoshan , Wang Yuchuan , CAO Shuliang , Gui Shaobo
Published: July 2015

Purpose

– The purpose of this paper is to elucidate the detailed flow field and cavitation effect in the centrifugal pump volute at partial load condition.

Design/methodology/approach

– Unsteady flows in a centrifugal pump volute at non-cavitation and cavitation conditions are investigated by using a computation fluid dynamics framework combining the re-normalization group k-e turbulence model and the mass transport cavitation model.

Findings

– The flow field in pump volute is very complicated at part load condition with large pressure gradient and intensive vortex movement. Under cavitation conditions, the dominant frequency for most of the monitoring points in volute transit from the blade passing frequency to a lower frequency. Generally, the maximum amplitudes of pressure fluctuations in volute at serious cavitation condition is twice than that at non-cavitation condition because of the violent disturbances caused by cavitation shedding and explosion.

Originality/value

– The detailed flow field and cavitation effect in the centrifugal pump volute at partial load condition are revealed and analysed.
A simple meshless method for challenging engineering problems
Authors: Shojaei Arman , Boroomand Bijan , Mossaiby Farshid
Published: July 2015

Purpose

– The purpose of this paper is to present a simple meshless solution method for challenging engineering problems such as those with high wave numbers or convection-diffusion ones with high Peclet number. The method uses a set of residual-free bases in a local form.

Design/methodology/approach

– The residual-free bases, called here as exponential basis functions, are found so that they satisfy the governing equations within each subdomain. The compatibility between the subdomains is weakly satisfied by enforcing the local approximation of the main state variables pass through the data at nodes surrounding the central node of the subdomain. The central state variable is first recovered from the approximation and then re-assigned to the central node to construct the associated equation. This leads to the least compatibility required in the solution, e.g. C0 continuity in Laplace problems.

Findings

– The authors shall show that one can solve a variety of problems with regular and irregular point distribution with high convergence rate. The authors demonstrate that this is impossible to achieve using finite element method. Problems with Laplace and Helmholtz operators as well as elasto-static problems are solved to demonstrate the effectiveness of the method. A convection-diffusion problem with high Peclet number and problems with high wave numbers are among the examples. In all cases, results with high rate of convergence are obtained with moderate number of nodes per cloud.

Originality/value

– The paper presents a simple meshless method which not only is capable of solving a variety of challenging engineering problems but also yields results with high convergence rate.
GFEM for modal analysis of 2D wave equation
Authors: Torii André Jacomel , Machado Roberto Dalledone , Arndt Marcos
Published: July 2015

Purpose

– The purpose of this paper is to present an application of the Generalized Finite Element Method (GFEM) for modal analysis of 2D wave equation.

Design/methodology/approach

– The GFEM can be viewed as an extension of the standard Finite Element Method (FEM) that allows non-polynomial enrichment of the approximation space. In this paper the authors enrich the approximation space with sine e cosine functions, since these functions frequently appear in the analytical solution of the problem under study. The results are compared with the ones obtained with the polynomial FEM using higher order elements.

Findings

– The results indicate that the proposed approach is able to obtain more accurate results for higher vibration modes than standard polynomial FEM.

Originality/value

– The examples studied in this paper indicate a strong potential of the GFEM for the approximation of higher vibration modes of structures, analysis of structures subject to high frequency excitations and other problems that concern high frequency oscillatory phenomena.
An efficient method for seismic analysis of structures
Authors: Kaveh A. , Rahami H. , Shojaei Iman
Published: July 2015

Purpose

– The purpose of this paper is to present an efficient method for dynamic analysis of structures utilizing a modal analysis with the main purpose of decreasing the computational complexity of the problem. In traditional methods, the solution of initial-value problems (IVPs) using numerical methods like finite difference method leads to step by step and time-consuming recursive solutions.

Design/methodology/approach

– The present method is based on converting the IVP into boundary-value problems (BVPs) and utilizing the features of the latter problems in efficient solution of the former ones. Finite difference formulation of BVPs leads to matrices with repetitive tri-diagonal and block tri-diagonal patterns wherein the eigensolution and matrix inversion are obtained using graph products rules. To get advantage of these efficient solutions for IVPs like the dynamic analysis of single DOF systems, IVPs are converted to boundary-value ones using mathematical manipulations. The obtained formulation is then generalized to the multi DOF systems by utilizing modal analysis.

Findings

– Applying the method to the modal analysis leads to a simple and efficient formulation. The laborious matrix inversion and eigensolution operations, of computational complexities of O(n2.373) and O(n3), respectively, are converted to a closed-form formulation with summation operations.

Research limitations/implications

– No limitation.

Practical implications

– Swift analysis has become possible.

Originality/value

– Suitability of solving IVPs and modal analysis using conversion and graph product rules is presented and applied to efficient seismic optimal analysis and preliminary design.
A constraint and algorithm for stress-based evolutionary structural optimization of the tie-beam problem
Authors: Zhang Da-Ke , Liang Sheng , Yang Yi-Chao , Zhou Hai-Tao
Published: July 2015

Purpose

– The purpose of this paper is to present a constraint and corresponding algorithm enhancing the evolutionary structural optimization (ESO) method, aiming to circumvent its structure break down problem in some special cases, such as the tie-beam problem.

Design/methodology/approach

– A virtual soft material introduced to an element will change the stiffness of the element and may consequently change the stress distribution of that element and its neighbors. With this property, the virtual stiffness of the selected element is calculated and the threshold of the stress changes is derived. The stress threshold is used to evaluate the role of an element on the load path and therefore decide the contribution of the element to the structure. Adding this checking operation into the original ESO iterations enables validation of element removal.

Findings

– The reason for structure break down with the ESO method is that the element removal criterion of ESO only works for certain optimal objectives. It cannot guarantee that the structure does not fail. The proposed operation offers a stronger and stricter constraint condition for ESO’s element removal process, preventing the structure from breaking down in some special cases.

Originality/value

– The tests on several examples reported in the literature show that the proposed method has the same ability to achieve an optimum solution as the original ESO methods do, while avoiding incorrect deletion of structurally important elements. The benchmark tie-beam problem is solved successfully with this algorithm. The method can be used in other situations as well.
Seismic damage evaluation of reinforced concrete buildings with slit walls
Authors: Baetu Sergiu Andrei , Barbat Alex H , Ciongradi Ioan Petru , Baetu Georgeta
Published: July 2015

Purpose

– The purpose of this paper is to investigate a reinforced concrete multi-storey building with dissipative structural walls. These walls can improve the behaviour of a tall multi-storey building. The authors’ main objective is to evaluate the damage of a building with dissipative walls in comparison with that of a building with solid walls.

Design/methodology/approach

– In this paper, a comparative nonlinear dynamic analysis between a building with slit walls and then the same building with solid walls is performed by means of SAP2000 software and using a layer model. The solution to increase the seismic performance of a building with structural walls is to create slit zones with short connections in to the walls. The short connections are introduced as a link element with multi-linear pivot hysteretic plasticity behaviour. The hysteretic rules and parameters of these short connections were proposed by the authors and used in this analysis. In this study, the authors propose to evaluate the damage of a building with reinforced concrete slit walls with short connections using seismic analysis.

Findings

– Using the computational model created by the authors for the slit wall, a seismic analysis of a multi-storey building with slit walls was done. From the results obtained, the advantages of the proposed model are observed.

Originality/value

– Using a simple computational model, created by the authors, that consume low processing resources and reduces processing time, a nonlinear dynamic analysis on high-rise buildings was done. Unlike other studies on slit walls with short connections, which are focused mostly on the nonlinear dynamic behaviour of the short connections, in this paper the authors take into consideration the whole structural system, wall, connections and frames.
Entrepreneurial learning requires action on the meaning generated
Authors: Brink Tove , Madsen Svend Ole
Published: July 2015

Purpose

– The purpose of this paper is to reveal how managers of small- and medium-sized enterprises (SMEs) can utilise their participation in research-based training to enable innovation and growth.

Design/methodology/approach

– Action research and action learning from a longitudinal study of ten SME managers in the wind turbine industry are applied to reveal SME managers’ learning and the impact of the application of learning in the wind turbine industry.

Findings

– The findings of this study show that SME managers employ a practice-shaped, holistic, cross-disciplinary approach to learning. This learning approach is supported by theory dissemination and collaboration on perceived business challenges. Open-mindedness to new learning by SME managers and to cross-disciplinary collaboration with SME managers by university facilitators/researchers is required.

Research limitations/implications

– The research is conducted within the wind turbine industry, in which intense demands for innovation are pursued. The findings require verification in other industry contexts.

Practical implications

– This research contributes strategies for SME managers to utilise research-based training and for universities regarding how to work with SME training. In addition, public bodies can enhance their understanding of SMEs for innovation and growth. The learning approach that is suitable for specialisation in larger organisations is not suitable in the SME context.

Social implications

– SME learning is enhanced by a social approach to integrating essential large-scale industry players and other SME managers to create extended action and value from learning.

Originality/value

– The findings reveal the need for extended theory development for and a markedly different approach to SME training from that used for training managers in larger companies. This topic has received only limited attention in previous research.
The determinants of intellectual capital disclosure: a meta-analysis review
Authors: Eddine Chaabane Oussama Houssem , Abdullah Shamsul Nahar , Hamid Fatima Abdul , Hossain Dewan Mahboob
Published: July 2015

Purpose

– The study aims to examine the relationship between the corporate disclosure on intellectual capital and five firm characteristics, namely, size, leverage, profitability, age and industry type.

Design/methodology/approach

– The research uses a meta-analysis technique by taking 19 articles published between 2003 and 2013. Thus, this study integrates and accumulates the findings of prior studies.

Findings

– The research finds a significant relationship between intellectual capital disclosure (ICD) and the independent variables: size, profitability and industry.

Originality/value

– This study provides a systematic overview of the determinants of ICD by using a meta-analysis approach. A systematic analysis is currently lacking in the ICD literature; hence, this study attempts to resolve the mixed findings of prior studies.
Market anomalies, asset pricing models, and stock returns: evidence from the Indian stock market
Authors: Dash Saumya Ranjan , Mahakud Jitendra
Published: July 2015

Purpose

– This paper aims to investigate whether the use of conditional and unconditional Fama and French (1993) three-factor and Carhart (1997) four-factor asset pricing models (APMs) captures the role of asset pricing anomalies in the context of emerging stock market like India.

Design/methodology/approach

– The first step time series regression approach has been used to drive the risk-adjusted returns of individual securities. For examining the predictability of firm characteristics or asset pricing anomalies on the risk-adjusted returns of individual securities, the panel data estimation technique has been used.

Findings

– Fama and French (1993) three-factor and Carhart (1997) four-factor model in their unconditional specifications capture the impact of book-to-market price and liquidity effects completely. When alternative APMs in their conditional specifications are tested, the importance of medium- and long-term momentum effects has been captured to a greater extent. The size, market leverage and short-term momentum effects still persist even in the case of alternative unconditional and conditional APMs.

Research limitations/implications

– The empirical analysis does not extend for different market scenarios like high and low volatile market or good and bad macroeconomic environment. Because of the constraint of data availability, the authors could not include certain important anomalies like net operating assets, change in gross profit margin, external equity and debt financing and idiosyncratic risk.

Practical implications

– Although the active investment approach in stock market shares a common ground of semi-strong form of market efficiency hypothesis which also supports the presence of asset pricing anomalies, less empirical evidence has been explored in this regard to support or repute such belief of practitioners. Our empirical findings make an attempt in this regard to suggest certain anomaly-based trading strategy that can be followed for active portfolio management.

Originality/value

– From an emerging market perspective, this paper provides out-of-sample empirical evidence toward the use of conditional Fama and French three-factor and Carhart four-factor APMs for the complete explanation of market anomalies. This approach retains its importance with respect to the comprehensiveness of analysis considering alternative APMs for capturing unique effects of market anomalies.
A deliberately emergent strategy – a key to successful city branding
Authors: Lindstedt Janne
Published: July 2015

Purpose

– The paper aims to address a neglected issue in the literature on place brand co-creation, namely, the strategic planning of the branding process. Furthermore, the paper demonstrates the benefits of a deliberately emergent strategy.

Design/methodology/approach

– A qualitative case study focusing on Turku, Finland, supports the development of the argument. In this study, branding of Turku is examined both during the European Capital of Culture 2011 (ECoC) project and after it.

Findings

– The contribution of the ECoC 2011 project – which was widely perceived as a success – to Turku’s brand was based on a deliberately emergent strategy. Afterwards, the local government has, however, chosen a different approach to branding.

Research limitations/implications

– Given the increasing popularity of brand thinking among practitioners all over the world, it would be meaningful for scholars to pay more attention to the application of brand co-creation in place branding strategies.

Practical implications

– The deliberately emergent branding strategy could be considered an approach to applying the idea of brand co-creation in practice. It enables local stakeholders to make their voices heard and results in increased credibility of a branding process.

Originality/value

– Place brand co-creation has not yet been examined from strategic planning’s point of view. The need for this kind of examination is apparent, because branding strategies have traditionally been based on the idea of static place identity. The Turku case helps to propose a solution in terms of the notion of deliberately emergent branding.
Approaches to validation and evaluation in qualitative studies of management accounting
Authors: Kihn Lili-Anne , Ihantola Eeva-Mari
Published: July 2015

Purpose

– This paper aims to address the reporting of validation and evaluation criteria in qualitative management accounting studies, which is a topic of critical debate in qualitative social science research. The objective of this study is to investigate the ways researchers have reported the use of evaluation criteria in qualitative management accounting studies and whether they are associated with certain paradigmatic affiliations.

Design/methodology/approach

– Building on the work of Eriksson and Kovalainen [Eriksson and Kovalainen (2008) Qualitative Methods in Business Research. London, Sage], the following three approaches are examined: the adoption of classic concepts of validity and reliability, the use of alternative concepts and the abandonment of general evaluation criteria. Content analysis of 212 case and field studies published during 2006 to February 2015 was conducted to be able to offer an analysis of the most recent frontiers of knowledge.

Findings

– The key empirical results of this study provide partial support for the theoretical expectations. They specify and refine Eriksson and Kovalainen’s (2008) classification system, first, by identifying a new approach to evaluation and validation and, second, by showing mixed results on the paradigmatic consistency in the use of evaluation criteria.

Research limitations/implications

– This paper is not necessarily exhaustive or representative of all the evaluation criteria developed; the authors focused on the explicit reporting of criteria only and the findings cannot be generalized. Somewhat different results might have been obtained if other journals, other fields of research or a longer period were considered.

Practical implications

– The findings of this study enhance the knowledge of alternative approaches and criteria to validation and evaluation. The findings can aid both in the evaluation of management accounting research and in the selection of appropriate evaluation approaches and criteria.

Originality/value

– This paper presents a synthesis of the literature (Table I) and new empirical findings that are potentially useful for both academic scholars and practitioners.
Lipper’s rating and the performance of unit trusts in Malaysia
Authors: Abdullah Ahmad Ridhuwan , Abdullah Nur Adiana Hiau
Published: July 2015

Purpose

– The purpose of this paper is to examine the risk-adjusted performance of rated funds and determine the usefulness of Lipper Leader rating of unit trusts in Malaysia during the period 2000 to 2010.

Design/methodology/approach

– The paper utilizes the Sharpe ratio, Treynor ratio, Jensen’s alpha and Fama-French three-factor model to measure performance.

Findings

– During the period of study, the performance of the market index and risk-free rate outperformed that of 68 equity unit trust funds in the 3-year, 5-year and 10-year investment horizons. The ranking, based on four performance measures, corresponds to Lipper rating for the lowest rated and leader funds, but not for the three- and four-key rated funds. Further, there is a significant difference in the performance of the five-key, four-key and three-key rated funds which outperform the lowest rated funds, indicating that Lipper rating is able to distinguish superior and inferior unit trust funds.

Research limitations/implications

– Some of the limitations in this study are that the indexes could be self-constructed. The existing index might not represent the asset allocation of the funds concerned. Additional variables might have to be considered when examining fund performance as they should correspond to the characteristics of a fund.

Practical implications

– The results indicate that Lipper rating classification could identify the highest and lowest performing funds. Therefore, investors could use this rating to make informed investment decisions without undertaking time-consuming analysis to ascertain the good- and bad-quality funds in the market.

Social implications

– The findings of this study could be used by the academia as another source of reference to enhance their understanding of the applicability of Lipper rating for unit trust funds in an emerging market.

Originality/value

– The contribution of this study is that it analyzes the effectiveness and capability of Lipper Leader rating in identifying quality funds in the context of an emerging market. Performance comparison between Lipper Leader rating and methods used in the portfolio theory bridges the theory-practice gap between practitioners and academics. To date, there have been no attempts to study and compare the ratings of advisory firms with theoretical performance measures, particularly in the context of Malaysia.
FVA and CVA under margining
Authors: Wu Lixin , Li Chonhong
Published: July 2015

Purpose

– The purpose of this paper is to provide a framework of replication pricing of derivatives and identify funding valuation adjustment (FVA) and credit valuation adjustments (CVA) as price components.

Design/methodology/approach

– The authors propose the notion of bilateral replication pricing. In the absence of funding cost, it reduces to unilateral replication pricing. The absence of funding costs, it introduces bid–ask spreads.

Findings

– The valuation of CVA can be separated from that of FVA, so-called split up. There may be interdependence between FVA and the derivatives value, which then requires a recursive procedure for their numerical solution.

Research limitations/implications

– The authors have assume deterministic interest rates, constant CDS rates and loss rates for the CDS. The authors have also not dealt with re-hypothecation risks.

Practical implications

– The results of this paper allow user to identify CVA and FVA, and mark to market their derivatives trades according to the recent market standards.

Originality/value

– For the first time, a line between the risk-neutral pricing measure and the funding risk premiums is drawn. Also, the notion of bilateral replication pricing extends the unilateral replication pricing.
Novel splice site mutation in the fumarate hydratase (FH) gene is associated with multiple cutaneous leiomyomas in a Japanese patient
Authors: Yoshinaga Yukina , Nakai Hiroyuki , Hayashi Ryota , Ito Akiko , Kariya Naoyuki , Ito Masaaki , Shimomura Yutaka
Published: July 2015

Cutaneous leiomyoma is a benign skin tumor that originates from the smooth muscle, such as the arrector pili muscle of the hair follicles. Familial cases with multiple cutaneous leiomyomas exist, which typically show an autosomal dominant inheritance trait. Most patients with the disease are known to carry heterozygous germ line mutations in the fumarate hydratase (FH) gene and can be complicated by tumors in internal organs, especially uterine leiomyoma and renal cell cancer in high frequency. In this study, we identified a Japanese male patient with multiple cutaneous leiomyomas and found a novel heterozygous splice site mutation, c.738 + 2T>A, in the FH gene of the patient, which was unexpectedly inherited from his unaffected father. Further analysis demonstrated loss of heterozygosity in the tumor tissue, which resulted in a hemizygote state of the mutant allele. Expression studies with the tumor tissue showed that the mutation led to skipping of exon 5 at mRNA levels, which was predicted to cause an in‐frame deletion of FH protein (p.Ser186_Gln246del). The protein structure analysis strongly suggested that the deletion would severely disrupt the conformation of the FH protein including the substrate‐binding domain, and thus would severely affect the expression and the function. Our findings further disclose the molecular basis of multiple cutaneous leiomyomas and also provide precious information to the mutation carriers in the family for an early diagnosis of renal cell cancer in the future.
Developmental environment mediates male seminal protein investment in Drosophila melanogaster
Authors: Wigby Stuart , Perry Jennifer C. , Kim Yon‐Hee , Sirot Laura K.
Published: July 2015

Males of many species fine‐tune their ejaculates in response to sperm competition risk. Resource availability and the number of competitors during development can also strongly influence sperm production. However, despite the key role of seminal proteins in mediating reproductive processes, it is unclear whether seminal protein investment is dependent on the developmental environment.

We manipulated the developmental environment of Drosophila melanogaster by rearing flies at low and high density. As expected, this resulted in large and small (i.e. high and low condition) adult phenotypes, respectively.

As predicted, large males produced more of two key seminal proteins, sex peptide (SP) and ovulin, and were more successful at obtaining matings with both virgin and previously mated females. However, there was only a weak and non‐significant trend for large males to transfer more absolute quantities of SP at mating, and thus, small males ejaculated proportionally more of their stored accessory gland SP resources.

Males transferred more receptivity‐inhibiting SP to large females. Despite this, large females remated more quickly than small females and thus responded to their developmental environment over and above the quantity of SP they received.

The results are consistent with two non‐mutually exclusive hypotheses. First, flies might respond to condition‐dependent reproductive opportunities, with (i) small males investing heavily in ejaculates when mating opportunities arise and large males strategically partitioning SP resources and (ii) small females remating at reduced rates because they have higher mating costs or need to replenish sperm less often.

Second, flies may be primed by their larval environment to deal with similar adult population densities, with (i) males perceiving high density as signalling increased competition, leading small males to invest proportionally more SP resources at mating and (ii) females perceiving high density as signalling abundant potential mates, leading to a higher sexual receptivity threshold.

Thus, by influencing the mating frequencies of both sexes, as well as the quantity of seminal proteins produced by males and received by females, the developmental environment is likely to have far‐reaching and sex‐specific consequences for sexual selection and sexual conflict.
Clinical pharmacology of dipeptidyl peptidase 4 inhibitors indicated for the treatment of type 2 diabetes mellitus
Authors: Chen Xiao‐Wu , He Zhi‐Xu , Zhou Zhi‐Wei , Yang Tianxin , Zhang Xueji , Yang Yin‐Xue , Duan Wei , Zhou Shu‐Feng
Published: July 2015

Dipeptidyl peptidase‐4 (DPP‐4) inhibitors are a class of oral antidiabetic drugs that improve glycaemic control without causing weight gain or increasing hypoglycaemic risk in patients with type 2 diabetes mellitus (T2DM). The eight available DPP‐4 inhibitors, including alogliptin, anagliptin, gemigliptin, linagliptin, saxagliptin, sitagliptin, teneligliptin, and vildagliptin, are small molecules used orally with identical mechanism of action and similar safety profiles in patients with T2DM. DPP‐4 inhibitors may be used as monotherapy or in double or triple combination with other oral glucose‐lowering agents such as metformin, thiazolidinediones, or sulfonylureas. Although DPP‐4 inhibitors have the same mode of action, they differ by some important pharmacokinetic and pharmacodynamic properties that may be clinically relevant in some patients. The main differences between the eight gliptins include: potency, target selectivity, oral bioavailability, elimination half‐life, binding to plasma proteins, metabolic pathways, formation of active metabolite(s), main excretion routes, dosage adjustment for renal and liver insufficiency, and potential drug‐drug interactions. The off‐target inhibition of selective DPP‐4 inhibitors is responsible for multiorgan toxicities such as immune dysfunction, impaired healing, and skin reactions. As a drug class, the DPP‐4 inhibitors have become accepted in clinical practice due to their excellent tolerability profile, with a low risk of hypoglycaemia, a neutral effect on body weight, and once‐daily dosing. It is unknown if DPP‐4 inhibitors can prevent disease progression. More clinical studies are needed to validate the optimal regimens of DPP‐4 inhibitors for the management of T2DM when their potential toxicities are closely monitored.
Myocardial protection induced by fentanyl in pigs exposed to high‐dose adrenaline
Authors: da Luz Vinicius Fernando , Otsuki Denise Aya , Gonzalez Maria Margarita Castro , Negri Elnara Marcia , Caldini Elia Garcia , Damaceno‐Rodrigues Nilsa Regina , Malbouisson Luiz Marcelo Sá , Viana Bruno Gonçalves , Vane Matheus Fachini , Carmona Maria Jose Carvalho
Published: July 2015

The use of high doses of adrenaline is common in critical patients, especially during cardiac arrest. During these situations, myocardial dysfunction can be a result of multiple factors, including adrenaline use. In addition, opioids have been shown to have anti‐arrhythmic and anti‐ischemic mechanisms that may confer cardiac protection. This study aimed to evaluate the effects of fentanyl on myocardial function in pigs exposed to high‐dose adrenaline. After institutional ethics committee approval, 26 pigs were randomly allocated to receive either 20 μg/kg fentanyl (n = 10; fentanyl group) administered 5 min before five doses of adrenaline (20 μg/kg), equivalent‐volume saline (n = 10; saline group) using the same adrenaline dosing protocol, or neither fentanyl nor adrenaline (n = 6; sham group). The fentanyl group showed lower levels of troponin at the end of the sixth hour compared with the saline group (1.91 ± 1.47 vs 5.44 ± 5.35 ng/mL, P = 0.019). Transmission electron microscopy and immunohistochemistry also showed less myocardial injury in the fentanyl group. The conclusion was reached that fentanyl attenuates myocardial injury caused by high‐dose adrenaline without blunting the hemodynamic effect of adrenaline.
Pyridostigmine enhances atrial tachyarrhythmias in aging spontaneously hypertensive rats
Authors: Sayin Halil , Scridon Alina , Oréa Valérie , Chapuis Bruno , Chevalier Philippe , Barrès Christian , Julien Claude
Published: July 2015

This study examined whether chronic administration of pyridostigmine, a reversible cholinesterase inhibitor, would exacerbate episodes of spontaneous atrial tachyarrhythmia (AT) in conscious, aging, spontaneously hypertensive rats (SHRs). Telemetric recordings of electrocardiogram (ECG, n = 5) and ECG/arterial pressure (n = 3) were performed in male 49‐week old SHRs. After a 1‐week period of continuous recording under baseline conditions, rats were implanted with osmotic minipumps that delivered pyridostigmine (15 mg/kg/day subcutaneously) for either 1 (n = 8) or 3 (n = 5) weeks. In the latter case, sympathovagal balance was assessed during the last infusion week by measuring heart rate (HR) changes in response to administration of cardiac autonomic blockers. An additional 1‐week recording was performed after explantation of minipumps. Significant (P = 0.02) reductions in HR with no consistent changes in arterial pressure were observed. Frequency and duration of AT episodes were increased by pyridostigmine (0.01 ≤ P ≤ 0.07). This increase was sustained across the 3‐week treatment period and reversible after cessation of treatment. Autonomic blockade revealed that intrinsic HR was above (P = 0.04) resting HR, pointing to a shift of sympathovagal balance towards vagal predominance. However, the respiratory‐related component of HR variability (high‐frequency power of RR interval) was lowered (P = 0.01) by pyridostigmine treatment, indicating reduced vagal modulation of HR. The results are consistent with a pathogenic role of the parasympathetic nervous system in the aging SHR model, and raise the possibility that sustained vagal activation may facilitate atrial arrhythmias.
Both Ox1R and Ox2R orexin receptors contribute to the cardiorespiratory response evoked from the perifornical hypothalamus
Authors: Beig Mirza I , Horiuchi Jouji , Dampney Roger AL , Carrive Pascal
Published: July 2015

Orexin/hypocretin neurons are located in and around the perifornical hypothalamus. Disinhibition of this area in the anaesthetized preparation evokes cardiorespiratory changes that can be reduced to nearly half or more by systemic Almorexant, a dual receptor antagonist of the two known orexin receptors, Ox1R and Ox2R. It is not clear if these reductions result from the blockade of one receptor or both. To determine the contribution of the two receptors, we compared the effects of Almorexant to those of the selective Ox1R antagonist ACT335827 and the selective Ox2R antagonists EMPA and TCS‐OX2‐29. Bicuculline (20 pmol) was injected in the perifornical hypothalamus of urethane‐anaesthetized rats before and after administration of the drugs (all 15 mg/kg, intravenously). The pressor, tachycardic and tachypneic responses to bicuculline were attenuated/reduced by ACT335827 (by 19%, ns; 10%, ns and 24%, P < 0.01, respectively), EMPA (by 35% P < 0.01; 6%, ns; and 26% P < 0.05) and TCS‐OX2‐29 (by 13%, ns; 10%, ns and 42%, P < 0.001). These reductions represented only a fraction of the reduction after Almorexant (by 43%, P < 0.001; 42%, P < 0.001 and 65% P < 0.001). However, when the selective Ox1R and Ox2R antagonists were given in combination, the reductions were greater and closer to those of Almorexant (ACT335827 + EMPA, by 26%, P < 0.05; 24%, P < 0.05 and 47%, P < 0.001; ACT335827 + TCS‐OX2‐29, by 40%, P < 0.01; 26%, P < 0.001 and 59%, P < 0.0001). This was particularly clear with the tachypneic response. These results suggest that both orexin receptors contribute to the cardiorespiratory response evoked from the hypothalamus under anaesthesia. They are consistent with our previous study in the conscious animal.
Unions and involuntary job separations
Authors: Pierse Tom , McHale John
Published: July 2015

In contrast to the extensive literature on the effects of unions on wages, productivity and voluntary job endings, the effect of unions on involuntary job endings has received relatively little attention. This article demonstrates how unions alter involuntary job separation (redundancies, temporary job endings and dismissals) rates at different tenure levels using the British Household Panel Survey data from 1991 to 2008. A novel finding is that being a union member reduces a person's redundancy probability at low‐tenure levels, relative to an employee of a non‐unionised firm, but has no significant effect at high tenure levels. Union membership and union recognition are not related to different rates of temporary job endings.