bluuebunny/crossref_metadata_2025 huggingface dataset:
Transient local adaptation and source–sink dynamics in experimental populations experiencing spatially heterogeneous environments
Authors: Bisschop Karen , Mortier Frederik , Etienne Rampal S. , Bonte Dries
Published: June 2019

Local adaptation is determined by the strength of selection and the level of gene flow within heterogeneous landscapes. The presence of benign habitat can act as an evolutionary stepping stone for local adaptation to challenging environments by providing the necessary genetic variation. At the same time, migration load from benign habitats will hinder adaptation. In a community context, interspecific competition is expected to select against maladapted migrants, hence reducing migration load and facilitating adaptation. As the interplay between competition and spatial heterogeneity on the joint ecological and evolutionary dynamics of populations is poorly understood, we performed an evolutionary experiment using the herbivore spider mite
Tetranychus urticae
as a model. We studied the species's demography and local adaptation in a challenging environment that consisted of an initial sink (pepper plants) and/or a more benign environment (cucumber plants). Half of the experimental populations were exposed to a competitor, the congeneric
T. ludeni
. We show that while spider mites only adapted to the challenging pepper environment when it was spatially interspersed with benign cucumber habitat, this adaptation was only temporary and disappeared when the populations in the benign cucumber environment were expanding and spilling-over to the challenging pepper environment. Although the focal species outcompeted the competitor after about two months, a negative effect of competition on the focal species’s performance persisted in the benign environment. Adaptation to challenging habitat in heterogeneous landscapes thus highly depends on demography and source–sink dynamics, but also on competitive interactions with other species, even if they are only present for a short time span.
Predation shapes sperm performance surfaces in guppies
Authors: Devigili Alessandro , Evans Jonathan P. , Fitzpatrick John L.
Published: June 2019

Sperm velocity is a key determinant of competitive fertilization success in many species. Selection is therefore expected to favour the evolution of faster sperm when the level of sperm competition is high. However, several aspects can determine the direction and strength of selection acting on this key performance trait, including ecological factors that influence both sperm competition and the strength of selection acting on correlated traits that may constrain evolutionary responses in sperm velocity. Here, we determine how a key ecological variable, the level of predation, shapes sperm swimming speed across 18 Trinidadian populations of guppies (
Poecilia reticulata
). We use performance analysis, a statistical tool akin to the familiar methods of multivariate selection analyses, to determine how the level of predation influences sperm velocity (modelled as a performance trait) when accounting for correlated pre- and postcopulatory traits that are also impacted by predation. We show that predation affects the combination of pre- and postcopulatory traits that ultimately predict sperm performance. Overall, we report evidence for disruptive relationships between sperm performance and combinations of ornaments and sperm morphology, but the specific combinations of traits that predict sperm velocity depended on the level of predation. These analyses underscore the complex nonlinear interrelationships among pre- and postcopulatory traits and the importance of considering ecological factors that may ultimately change the way in which multiple traits interact to determine a trait's performance value. As such, our results are likely to be broadly applicable across systems where selection is influenced by ecological conditions.
Thermal landscape change as a driver of ectotherm responses to plant invasions
Authors: Garcia Raquel A. , Clusella-Trullas Susana
Published: June 2019

A growing body of research demonstrates the impacts of invasive alien plants on native animals, but few studies consider thermal effects as a driver of the responses of native organisms. As invasive alien plants establish and alter the composition and arrangement of plant communities, the thermal landscapes available to ectotherms also change. Our study reviews the research undertaken to date on the thermal effects of alien plant invasions on native reptiles, amphibians, insects and arachnids. The 37 studies published between 1970 and early 2019 portray an overall detrimental effect of invasive plants on thermal landscapes, ectothermic individuals' performance and species abundance, diversity and composition. With a case study of a lizard species, we illustrate the use of thermal ecology tools in plant invasion research and test the generality of alien plant effects: changes in thermoregulation behaviour in invaded landscapes varied depending on the level of invasion and lizard traits. Together, the literature review and case study show that thermal effects of alien plants on ectotherms can be substantial albeit context-dependent. Further research should cover multiple combinations of native/invasive plant growth forms, invasion stages and ectotherm traits. More attention is also needed to test causality along the chain of effects from thermal landscapes to individuals, populations and communities.
Limitations of machine learning in psychiatry: Participation in the PAC 2018 depression challenge
Authors: Eitel Fabian , Stober Sebastian , Waller Lea , Dorfschmidt Lena , Walter Henrik , Ritter Kerstin
Published: June 2019

The authors have withdrawn this manuscript because the results were posted in error. The authors do not wish this work to be cited as reference for the project. Please contact the corresponding author if you have any questions.
Notch signaling is required for survival of the germline stem cell lineage in testes ofDrosophila melanogaster
Authors: Ng Chun L. , Yue Qian , Cordula Schulz
Published: June 2019

In all metazoan species, sperm is produced from germline stem cells. These self-renew and produce daughter cells that amplify and differentiate dependent on interactions with somatic support cells. In the male gonad ofDrosophila melanogaster, the germline and somatic cyst cells co-differentiate as cysts, an arrangement in which the germline is completely enclosed by cytoplasmic extensions from the cyst cells. Notch is a developmentally relevant receptor in a pathway requiring immediate proximity with the signal sending cell. Here, we show that Notch is expressed in the cyst cells ofwild-typetestes. Notch becomes activated in the transition zone, an apical area of the testes in which the cyst cells express stage-specific transcription factors and the enclosed germline finalizes transit-amplifying divisions. Reducing the ligand Delta from the germline cells via RNA-Interference or reducing the receptor Notch from the cyst cells via CRISPR resulted in cell death concomitant with loss of germline cells from the transition zone. This shows that Notch signaling is essential for the survival of the germline stem cell lineage.
Namdinator – automatic molecular dynamics flexible fitting of structural models into cryo-EM and crystallography experimental maps
Authors: Kidmose Rune Thomas , Juhl Jonathan , Nissen Poul , Boesen Thomas , Karlsen Jesper Lykkegaard , Pedersen Bjørn Panyella
Published: June 2019

Model building into experimental maps is a key element of structural biology, but can be both time consuming and error prone for low-resolution maps. Here we present Namdinator, an easy-to-use tool that enables the user to run a molecular dynamics flexible fitting simulation followed by real-space refinement in an automated manner through a pipeline system. Namdinator will modify an atomic model to fit within cryo-EM or crystallography density maps, and can be used advantageously for both the initial fitting of models, and for a geometrical optimization step to correct outliers, clashes and other model problems. We have benchmarked Namdinator against 39 deposited cryo-EM models and maps, and observe model improvements in 34 of these cases (87%). Clashes between atoms were reduced, and the model-to-map fit and overall model geometry were improved, in several cases substantially. We show that Namdinator is able to model large-scale conformational changes compared to the starting model. Namdinator is a fast and easy tool for structural model builders at all skill levels. Namdinator is available as a web service (https://namdinator.au.dk), or it can be run locally as a command-line tool.
Adaptation of the penalty function method to genetic algorithm in electromagnetic devices designing
Authors: Knypiński Łukasz
Published: June 2019

Purpose

The purpose of this paper is to elaborate the effective method of adaptation of the external penalty function to the genetic algorithm.

Design/methodology/approach

In the case of solving the optimization tasks with constraints using the external penalty function, the penalty term has a larger value than the primary objective function. The sigmoidal transformation is introduced to solve this problem. A new method of determining the value of the penalty coefficient in subsequent iterations associated with the changing penalty has been proposed. The proposed approach has been applied to the optimization of an electromagnetic linear actuator, and the mathematical model of the devices contains equations of the magnetic field, by taking into account the nonlinearity of ferromagnetic material.

Findings

The proposed new approach of the penalty function method consists in the reduction of the external penalty function in successive penalty iterations instead of its increase as it is in the classical method. In addition, the method of normalization of constraints during the formulation of optimization problem has a significant impact on the obtained results of optimization calculations.

Originality/value

The proposed approach can be applied to solve constrained optimization tasks in designing of electromagnetic devices.
Interpreting and semantically describing Chinese traditional brocade: Xilankapu
Authors: Cheng Xiufeng , Yang Jinqing , Jiang Ling , Hu Anlei
Published: June 2019

Purpose

The purpose of this paper is to introduce an interpreting schema and semantic description framework for a collection of images of Xilankapu, a traditional Chinese form of embroidered fabric and brocade artwork.

Design/methodology/approach

First, the authors interpret the artwork of Xilankapu through Gillian Rose’s “four site” theory by presenting how the brocades were made, how the patterns of Xilankapu are classified and the geometrical abstraction of visual images. To further describe the images of this type of brocade, this paper presents semantic descriptions that include objective–non-objective relations and a multi-layered semantic framework. Furthermore, the authors developed corresponding methods for scanning, storage and indexing images for retrieval.

Findings

As exploratory research on describing, preserving and indexing images of Xilankapu in the context of the preservation of cultural heritage, the authors collected 1,000+ images of traditional Xilankapu, classifying and storing some of the images in a database. They developed an index schema that combines concept- and content-based approaches according to the proposed semantic description framework. They found that the framework can describe, store and preserve semantic and non-semantic information of the same image. They relate the findings of this paper to future research directions for the digital preservation of traditional cultural heritages.

Research limitations/implications

The framework has been designed especially for brocade, and it needs to be extended to other types of cultural image.

Originality/value

The semantic description framework can describe connotative semantic information on Xilankapu. It can also assist the later information retrieval work in organizing implicit information about culturally related visual materials.
Response awareness and instructional self-efficacy: influences on intent
Authors: Mutchler Leigh A.
Published: June 2019

Purpose

This paper aims to examine the influence of response awareness on behavioral intent, and introduces instructional self-efficacy, a construct rarely examined within the context of information security (ISec).

Design/methodology/approach

A Web-based survey was conducted and a total of 211 valid responses were analyzed. The relationships among response awareness, instructional self-efficacy and behavioral intent were examined through a three-phase structural equation modeling analysis.

Findings

The results indicate that even at low levels, response awareness has a strong influential effect on the behavioral intent to perform the secure response and on the self-efficacy to instruct others to perform the response. Instructional self-efficacy was also found to be a significant predictor of behavioral intent to perform the response. Finally, evidence was found indicating instructional self-efficacy fully mediates the response awareness to the behavioral intent relationship.

Research limitations/implications

Because of the characteristics of the population, the focus on a single ISec response and the dependent variable of behavioral intent rather than actual behavior, the generalizability of the findings is impacted.

Practical implications

The results contribute to practice by confirming the importance of response awareness and of instructional self-efficacy within an ISec context. Specific implications include the indication that informal communications about ISec issues among peers should be encouraged and that instructional self-efficacy should be targeted within ISec awareness training programs.

Originality/value

This paper’s parsimonious model defined response awareness as vicarious experience with a response and presented instructional self-efficacy, a construct novel to ISec studies that was found to be a significant influence within the relationship between response awareness and behavioral intent.
Quantitative research in tourism and hospitality: an agenda for best-practice recommendations
Authors: Assaf A. George , Tsionas Mike G.
Published: June 2019

Purpose

This paper aims to serve as an important guide for more rigorous quantitative research in tourism and hospitality.

Design/methodology/approach

This paper relies on comments from several methodological experts in the field, as well as the authors’ main observation of the literature.

Findings

This paper identifies ten important areas of concern. In each of these areas, the authors provide recommendations for best practices.

Research limitations/implications

There are certainly other issues and concerns that are not covered in this paper. However, the issues addressed can be applied or generalized to most methodological contexts.

Originality/value

This paper does not present results from original research but provides interesting and comprehensive recommendations for more rigorous quantitative research.
News personalization for peace: how algorithmic recommendations can impact conflict coverage
Authors: Bastian Mariella , Makhortykh Mykola , Dobber Tom
Published: June 2019

Purpose

The purpose of this paper is to develop a conceptual framework for assessing what are the possibilities and pitfalls of using algorithmic systems of news personalization – i.e. the tailoring of individualized news feeds based on users’ information preferences – for constructive conflict coverage in the context of peace journalism, a journalistic paradigm calling for more diversified and creative war reporting.

Design/methodology/approach

The paper provides a critical review of existing research on peace journalism and algorithmic news personalization, and analyzes the intersections between the two concepts. Specifically, it identifies recurring pitfalls of peace journalism based on empirical research on constructive conflict coverage and then introduces a conceptual framework for analyzing to what degree these pitfalls can be mediated – or worsened – through algorithmic system design.

Findings

The findings suggest that AI-driven distribution technologies can facilitate constructive war reporting, in particular by countering the effects of journalists’ self-censorship and by diversifying conflict coverage. The implementation of these goals, however, depends on multiple system design solutions, thus resonating with current calls for more responsible and value-sensitive algorithmic design in the domain of news media. Additionally, our observations emphasize the importance of developing new algorithmic literacies among journalists both to realize the positive potential of AI for promoting peace and to increase the awareness of possible negative impacts of new systems of content distribution.

Originality/value

The article particle is the first to provide a comprehensive conceptualization of the impact of new content distribution techniques on constructive conflict coverage in the context of peace journalism. It also offers a novel conceptual framing for assessing the impact of algorithmic news personalization on reporting traumatic and polarizing events, such as wars and violence.
Finite element method for solving asphalt mixture problem
Authors: Lijun Wang , Qingbo Li
Published: June 2019

Purpose

Asphalt mixture is widely used in road engineering, and its performance research is particularly important. But the study of asphalt mixture performance needs a lot of tests, such as bending test, splitting test and so on. It also needs a lot of time and material resources. The purpose of this paper is to obtain test results through finite element numerical simulation, and show that this saves a lot of manpower and material resources.

Design/methodology/approach

The mechanical parameters of the material are obtained through uniaxial compression tests. The true stress and plastic strain are calculated according to nominal stress and nominal strain. A constitutive model is established. Then a finite element model of asphalt mixture is established. The numerical simulation and performance study of asphalt mixture bending test is carried out. At the same time, according to the above method, the asphalt mixture is subjected to freeze-thaw cycles and ultraviolet aging, and the mechanical parameters are obtained by a uniaxial compression test. A numerical model is established to simulate the bending characteristics of asphalt mixture after freeze-thaw cycles and ultraviolet aging.

Findings

A uniaxial compression test of the asphalt mixture is conducted to obtain nominal stress and nominal strain. The true stress and plastic strain are calculated and the elastic modulus is established with Poisson’s ratio as the elastic part, and the true stress and plastic strain as the plastic part. The model is constructed, the finite element model is established and the bending test is numerically simulated. The verified trend is consistent, and the method is feasible. According to the above method, the concrete is subjected to freeze-thaw cycle and ultraviolet aging, and the finite element model is established by using uniaxial compression test to obtain parameters. The bending test is simulated and the verification method is feasible. With the increase of the number of freeze-thaw cycles and the increase of UV aging time, the maximum bending strain of SBS modified asphalt mixture and matrix asphalt mixture is decreased .The low-temperature performance of SBS modified asphalt mixture is better than that of matrix asphalt mixture.

Originality/value

A method of simulating asphalt mixture test by finite element method numerical simulation is established. By using this method, the performance of asphalt mixture is studied, which saves a lot of manpower and material resources. At the same time, this method can be used to study the characteristics of asphalt mixture under complex conditions.
Effects on knee joint force from a body weight load reduction system driven by rubber-less artificial muscle
Authors: Saito Naoki , Satoh Toshiyuki , Saga Norihiko
Published: June 2019

Purpose

The purpose of this study is to confirm that the body weight load reduction system which is developed by us is effective to reduce the knee joint force of the walking user. This system is driven by pneumatic artificial muscle, functions as a mobile walking assist system.

Design/methodology/approach

The developed body weight load reduction system driven by rubber-less artificial muscle (RLAM) was tested experimentally. Simple force feedback control is applied to the RLAM. The system moves as synchronized with vertical movement of the walking user. The knee joint force during walking experiments conducted using this system is estimated by measurement of floor reaction force and position data of lower limb joints.

Findings

The knee joint force during walking is reduced when using this system. This system contributes to smooth change of knee joint force when the lower limb contacts the floor.

Practical implications

This lightweight body weight load reduction system is particularly effective for realizing easy-to-use mobile walking assist system.

Originality/value

A lightweight body weight load reduction system using pneumatic artificial muscle is a novel proposal. Additionally, these new evaluation results demonstrate its effectiveness for reducing knee joint force during walking.
Agent-based modelling and economic complexity: a diversified perspective
Authors: Schinckus Christophe
Published: June 2019

Purpose

The term “agent-based modelling” (ABM) is a buzzword which is widely used in the scientific literature even though it refers to a variety of methodologies implemented in different disciplinary contexts. The numerous works dealing with ABM require a clarification to better understand the lines of thinking paved by this approach in economics. All modelling tasks are a means and a source of knowledge, and this epistemic function can vary depending on the methodology. this paper is to present four major ways (deductive, abductive, metaphorical and phenomenological) of implementing an agent-based framework to describe economic systems. ABM generates numerous debates in economics and opens the room for epistemological questions about the micro-foundations of macroeconomics; before dealing with this issue, the purpose of this paper is to identify the kind of ABM the author can find in economics.

Design/methodology/approach

The profusion of works dealing with ABM requires a clarification to understand better the lines of thinking paved by this approach in economics. This paper offers a conceptual classification outlining the major trends of ABM in economics.

Findings

There are four categories of ABM in economics.

Originality/value

This paper suggests a methodological categorization of ABM works in economics.
Good problem solvers? Leveraging knowledge sharing mechanisms and management support
Authors: Galeazzo Ambra , Furlan Andrea
Published: June 2019

Purpose

Organizational learning relies on problem-solving as a way to generate new knowledge. Good problem solvers should adopt a problem-solving orientation (PSO) that analyzes the causes of problems to arrive at an effective solution. The purpose of this paper is to investigate this relevant, though underexplored, topic by examining two important antecedents of PSO: knowledge sharing mechanisms and transformational leaders’ support.

Design/methodology/approach

Hierarchical linear modeling analyses were performed on a sample of 131 workers in 12 plants. A questionnaire was designed to collect data from shop-floor employees. Knowledge sharing was measured using the mechanisms of participative practices and standardized practices. Management support was assessed based on the extent to which supervisors engaged in transformational leadership.

Findings

Knowledge sharing mechanisms are an antecedent of PSO behavior, but management support measured in terms of transformational leadership is not. However, transformational leadership affects the use of knowledge sharing mechanisms that, in turn, is positively related to PSO behavior.

Practical implications

The research provides practical guidance for practitioners to understand how to manage knowledge in the workplace to promote employees’ PSO behaviors.

Originality/value

Though problem-solving activities are intrinsic in any working context, PSO is still very much underrepresented and scarcely understood in knowledge management studies. This study fills this gap by investigating the antecedents of PSO behavior.
A unified model of organizational effectiveness
Authors: Sharma Nidhi , Singh Reetesh K.
Published: June 2019

Purpose

Scholars for long have been interested in finding effective ways to assess organizational effectiveness. However, lack of consensus on its definition, and consequently on measure parameters has dogged researchers, almost to the point that some academics have declared organizational effectiveness a subject that cannot be researched. The purpose of this paper is to present a unified model of organizational effectiveness by recognizing the underlying synergy in the body of research – a framework that could guide future research on organizational effectiveness as a comprehensive, but contextual paradigm.

Design/methodology/approach

This paper is based on extensive exploratory review and critique of extant literature on organizational effectiveness.

Findings

The lack of consensus among scholars on the meaning of organizational effectiveness and its measures is primarily the result of compartmentalized perspectives. The authors found that there is an underlying synergy among them. Basis a big picture review and analysis of extant literature, the authors have been able to identify a unifying framework for the apparently disparate and conflicting models of organizational effectiveness.

Practical implications

This paper can provide guidance to managers on appropriate selection of organizational effectiveness measures, and to scholars on developing a more holistic and pragmatic research approach on the subject. It can potentially lead to development of context-based scales that facilitate meaningful comparative studies.

Originality/value

This paper presents a unified model and framework for organizational effectiveness by building on the valuable but disparate contributions of previous researchers. The authors believe that this is a novel attempt that simplifies the discourse on organizational effectiveness, and will help to remove some of the negativity around the research subject.
Intersection of corrosion prevention strategy and practice
Authors: Pond Geoff , Abdullah Muhammad Ali , Turgeon Yves
Published: June 2019

Purpose

The purpose of this paper is to objectively evaluate the cost benefit of applying corrosion prevention coatings throughout a mid-life logistics fleet supporting the Canadian Army.

Design/methodology/approach

A database of maintenance records for an Army logistics vehicle throughout a four-year study period is mined. Statistical analysis (primarily ANOVA) accounting for the frequency of treatment and geographic region is executed.

Findings

Statistical analysis indicates counter-intuitive results. Vehicles that are most frequently treated to prevent corrosion incur the highest maintenance costs. Consultation with operational units suggests that a strategic approach to corrosion prevention is largely absent. Instead, vehicles are treated on an ad hoc basis, or – equivalently – on an as available basis.

Practical implications

Among high tempo organizations, vehicles most readily available to maintenance support are those that are in the greatest state of disrepair. Vehicles that are in better condition are preferred by operators for daily operations and are not available. Consequently, the vehicles that are subject to preventative maintenance most often are those near their end-of-life or are in disrepair and therefore gain little through further investments in corrosion prevention initiatives.

Originality/value

Clearly, having corrosion prevention compounds applied to a fleet on an ad hoc basis suffers from the natural bias occurring among operators to retain vehicles in best condition for operational purposes. Corrosion prevention requires a more strategic approach including disciplined maintenance operations in order to provide dividends on a fleet-wide basis.
An equivalent stress method to account for local buckling in beam finite elements subjected to fire
Authors: Maraveas Chrysanthos , Gernay Thomas , Franssen Jean-Marc
Published: June 2019

Purpose

The purpose of this paper is to present an improved temperature-dependent constitutive model for steel that accounts for local instabilities of slender plates using an effective stress-based method. This model can be easily implemented for use with Bernoulli beam finite elements (FEs) in the fire situation.

Design/methodology/approach

The constitutive model is derived by calibration on parametric numerical analysis on isolated plates subject to buckling at different elevated temperatures. The model is implemented in the FE software SAFIR and validation is performed against experimental and shell element analysis results.

Findings

A constitutive model based on an equivalent stress method is proposed as an efficient way to consider local buckling in steel members exposed to fire. The proposed stress–strain–temperature relationship is asymmetric and is modified in compression only, by reducing the proportional limit, the yield stress and the strain at yield stress. The reduction of these parameters depends on the plate’s boundary conditions, slenderness and temperature. The validation of the proposed model shows good agreement over a range of profile dimensions, temperatures and steel grades.

Research limitations/implications

The model is still giving conservative results for large compressive load eccentricities. An enhanced model is under development to improve the predictive capability under large eccentricities.

Practical implications

The proposed model, easily implemented into any finite element software, allows using fibre type (Bernoulli) beam FEs for modelling structures made of slender sections. This has major practical implications as beam elements are the workhorse used for simulating the behaviour of structures in fire. This model, thus makes it possible to simulate large structures with slender steel sections at a limited computational cost.

Originality/value

The paper presents a novel steel constitutive model based on an innovative approach to capture local buckling at the material level using an equivalent stress approach. The theoretical development, validation and perspectives for future improvements are presented.
The effects of a public indicator of accounting aggressiveness on managers’ financial reporting decisions
Authors: Hamilton Erin L. , Hirsch Rina M. , Rasso Jason T. , Murthy Uday S.
Published: June 2019

Purpose

The purpose of this paper is to examine how publicly available accounting risk metrics influence the aggressiveness of managers’ discretionary accounting decisions by making those decisions more transparent to the public.

Design/methodology/approach

The experiment used a 2 × 3 between-participants design, randomly assigning 122 financial reporting managers among conditions in which we manipulated whether the company was currently beating or missing analysts’ consensus earnings forecast and whether an accounting risk metric was indicative of low risk, high risk or a control. Participants chose whether to manage company earnings by deciding whether to report an amount of discretionary accruals that was consistent with the “best estimate” (i.e. no earnings management) or an amount above or below the best estimate.

Findings

Aggressive (income-increasing) earnings management is deterred when managers believe such behavior will cause their firm to be flagged as aggressive (i.e. high risk) by an accounting risk metric. Some managers attempt to “manage” the risk metric into an acceptable range through conservative (income-decreasing) earnings management. These results suggest that by making the aggressiveness of accounting choices more transparent, public risk metrics may reduce one type of earnings management (income-increasing), while simultaneously increasing another (income-decreasing).

Research limitations/implications

The operationalization of the manipulated variables of interest may limit the study’s generalizability.

Practical implications

Users of accounting risk metrics (e.g. investors, auditors, regulators) should be cautious when relying on such risk metrics that may be of limited reliability and usefulness due to managers’ incentives to manipulate their companies’ risk scores by being overly conservative in an effort to prevent being labeled “aggressive”.

Originality/value

By increasing the transparency of the aggressiveness of accounting choices, public risk metrics may reduce one type of earnings management (income-increasing), while simultaneously increasing another (income-decreasing).
How an unequal intra-firm resources distribution affect market share
Authors: Davcik Nebojsa , Grigoriou Nicholas
Published: June 2019

Purpose

The purpose of this paper is to address how marketing assets and resources of the firm perform under different product (brand) innovation conditions using the dynamic marketing capabilities (DMC) research perspective. The study contributes to the DMC research stream showing the effects and performance of heterogeneous firm drivers and resources. Academic research to date has paid a little attention to the interrelationship between market share as a performance metric, dynamic capabilities and product (brand) innovation. The current study bridges this knowledge gap by empirically validating the effects of DMC on market share performance output using panel data for 753 retail food brands.

Design/methodology/approach

The model was initially fitted with the β regression analysis and cluster analysis in the second step of the estimation procedure. The results of simulation by Monte Carlo experimentation are discussed.

Findings

The findings show that firms leverage their marketing capabilities unequally in the multi-brand portfolios, which leads to an unequal intra-firm distribution of assets and resources. The research contributes to the understanding of the brand competitive dynamics and appropriate deployment of assets and resources for improved firm performance.

Originality/value

These findings are useful for both academics and practitioners because they address new and future research. In doing so, the authors advance the firm performance and branding literature with extension in the DMC literature.
Reduction in Hg phytoavailability in soil using Hg‐volatilizing bacteria and biochar and the response of the native bacterial community
Authors: Chang Junjun , Yang Qingchen , Dong Jia , Ji Bohua , Si Guangzheng , He Fang , Li Benyan , Chen Jinquan
Published: June 2019

Biological approaches are considered promising and eco‐friendly strategies to remediate Hg contamination in soil. This study investigated the potential of two ‘green’ additives, Hg‐volatilizing bacteria (Pseudomonas sp. DC‐B1 and Bacillus sp. DC‐B2) and sawdust biochar, and their combination to reduce Hg(II) phytoavailability in soil and the effect of the additives on the soil bacterial community. The results showed that the Hg(II) contents in soils and lettuce shoots and roots were all reduced with these additives, achieving more declines of 12.3–27.4%, 24.8–57.8% and 2.0–48.6%, respectively, within 56 days of incubation compared to the control with no additive. The combination of DC‐B2 and 4% biochar performed best in reducing Hg(II) contents in lettuce shoots, achieving a decrease of 57.8% compared with the control. Pyrosequencing analysis showed that the overall bacterial community compositions in the soil samples were similar under different treatments, despite the fact that the relative abundance of dominant genera altered with the additives, suggesting a relatively weak impact of the additives on the soil microbial ecosystem. The low relative abundances of Pseudomonas and Bacillus, close to the background levels, at the end of the experiment indicated a small biological disturbance of the local microbial niche by the exogenous bacteria.
Orexin‐B‐like immunoreactivity in pituitary αMSH‐producing cells and median eminence GnRH‐containing fibres of the flat‐tailed house gecko
Authors: Suzuki Hirohumi , Yamamoto Toshiharu
Published: June 2019

We examined the distribution of the orexin‐like peptides in the pituitary and median eminence of the flat‐tailed house gecko (Hemidactylus platyurus) using immunohistochemistry. Orexin‐B‐like, but not orexin‐A‐like, immunoreactivity was detected in the pituitary, specifically in the pars intermedia, and these cells corresponded to alpha‐melanocyte‐stimulating hormone (αMSH)‐producing cells. Orexin‐B and αMSH secreted from pars intermedia may modulate secretion of adenohypophyseal cells in the pars distalis. In the median eminence, orexin‐B‐immunoreactive puncta and fibres were observed, and these structures corresponded to gonadotropin‐releasing hormone (GnRH)‐immunoreactive puncta and fibres. Orexin‐B secreted from GnRH‐containing neurons in the hypothalamus may affect thyrotropin‐releasing hormone‐containing neurons resulting in modulation of αMSH secretion of melanotrophs in the pars intermedia.
Formation of semi‐enveloped particles as a unique feature of a hepatitis B virus PreS1 deletion mutant
Authors: Jiang Bingfu , Wu Qingyan , Kuhnhenn Lisa , Akhras Sami , Spengler Catrina , Boller Klaus , Peiffer Kai‐Henrik , Hildt Eberhard
Published: June 2019

Background

Naturally occurring variants with deletions or mutations in the C‐terminal PreS1 domain from hepatitis B virus (HBV) chronically infected patients have been shown to promote HBsAg retention, inhibit HBsAg secretion and change the extracellular appearance of PreS1‐containing HBV particles (filaments and virions).

Aims

To study the impact of N‐terminal deletion in preS1 domain on viral secretion and morphogenesis.

Methods

An HBV mutant with 15 amino acids (aa 25‐39) deletion in N‐terminal preS1 was isolated. Intracellular and extracellular HBsAg were quantified by Western blot. Subcellular HBsAg distribution was analysed by confocal laser scanning microscopy. The viral morphology was characterised by sucrose density gradient ultracentrifugation, Western blot, electron microscopy, HBV mixed ELISA and HBV particle gel essay.

Results

Expression of this mutant genome released higher amounts of HBsAg in the form of shorter filaments. A significant fraction of semi‐enveloped virions was observed in the supernatant that has been unprecedented so far. Stepwise insertion of aa 25‐31, aa 32‐39 and aa 25‐39 increased the length of filaments. The rescue of aa 25‐31 and aa 25‐39 drastically reduced the amounts of extracellular HBsAg and semi‐enveloped virions, while such effects could not be observed after insertion of aa 32‐39, arguing against a simple spacer function of this region. The deletion and rescued mutants do not differ in subcellular HBsAg distribution and colocalisation with ER, Golgi and multivesicular bodies markers arguing against differences in release pathways.

Conclusion

N‐terminal PreS1‐domain (aa 25‐31) determines HBsAg secretion and triggers proper assembly of PreS1‐containing particles.
Future of Endoscopy: Brief review of current and future endoscopic resection techniques for colorectal lesions
Authors: Hossain Ejaz , Alkandari Asma , Bhandari Pradeep
Published: June 2019

Endoscopic treatment of colorectal lesions has seen major developments in the last decade. It is now considered curative for intramucosal and superficial submucosal cancers. Endoscopic Mucosal Resection in expert hands has very good outcomes with low complication rates but recurrence and inadequate treatment of early cancers remain an issue. This has led to a technical evolution that can lead to one piece resection of neoplasia. This includes a range of techniques from knife assisted snare resection (KAR), endoscopic submucosal dissection (ESD) to full thickness resections. This article reviews all the resection techniques and the evidence base behind them.
Brenneria spp. and Rahnella victoriana associated with acute oak decline symptoms on oak and hornbeam in Iran
Authors: Moradi‐Amirabad Yousef , Rahimian Heshmat , Babaeizad Valiollah , Denman Sandra
Published: June 2019

Decline diseases of forest trees are complex syndromes not attributable to single causal factors. In Iran, symptoms of decline disease have been observed in a number of native forest species including Quercus castaneifolia (chestnut‐leaved oak), Q. brantii (Persian oak) and Carpinus betulus (hornbeam). The symptoms are prevalent in the northern forests and the Zagros mountain forests. There are parallels between the disease in Iran and acute oak decline (AOD) reported in the UK, specifically the presence of weeping cankers, which have been attributed to a polybacterial complex wherein Brenneria goodwinii is considered a key necrogen. Based on the AOD symptomatology, and as a first step towards discovering potential causal agents of the stem weeping symptoms of affected trees in Iran, necrotic tissues were tested primarily for the presence of B. goodwinii. Symptomatic Q. castaneifolia and C. betulus from the Mazandaran Province and symptomatic Q. brantii from Kohgiluyeh and Boyerahmad Province were sampled. Isolation and culture on a selective medium yielded uniform bacterial colonies. Isolates were characterized using phenotypic and genotypic (DNA sequencing) tests. The isolates were phenotypically identical to members of Pectobacteriaceae and Yersiniaceae, specifically Brenneria and Rahnella spp. The nucleotide sequences of the 16S rRNA and housekeeping genes gyrB, infB and atpD (MLSA) amplified via PCR demonstrated that the isolates from the trees in Iran were indeed B. goodwinii, B. roseae subsp. roseae, Rahnella victoriana and an unknown species of Brenneria. Most bacteria isolated from non‐symptomatic trees were Gram‐positive, and Pseudomonas spp. were dominant, but bacterial species isolated from the diseased trees were not detected in healthy trees. Hypersensitivity response tests were positive, but inoculation on saplings was more variable with internal necrosis developing only once in the test period. Therefore, further testing is required. This is the first report of the incidence of B. goodwinii, B. roseae subsp. roseae, R. victoriana and Brenneria sp. associated with acute oak decline‐like symptoms on Q. castaneifolia, Q. brantii and C. betulus across the western forests of Iran and in the world.
Common oral diseases, hyposalivation and survival post‐HSCT, a longitudinal study
Authors: Uutela Pauliina , Passweg Jakob , Halter Jörg , Gerull Sabine , Weiger Roland , Mauramo Elina , Waltimo Tuomas , Mauramo Matti
Published: June 2019

Objectives

Haematopoietic stem cell transplantation (HSCT) recipients are at risk of side effects within the oral cavity. The purpose of this study was to examine progression of common oral diseases and hyposalivation and their associations with survival in allogeneic HSCT recipients.

Methods

Two hundred and sixty nine adult HSCT recipients treated with HSCT between 2008 and 2016 were included in this study. The associations of caries, decayed, missing, filled teeth (DMFT) index, radiological attachment loss and stimulated salivary flow rate with 6‐month survival and the progression of the oral disorders within 2 years were examined.

Results

Forty HSCT recipients (14.8%) deceased within 6 months post‐HSCT. Among the deceased recipients, hyposalivation and caries were more common pre‐HSCT than in recipients who survived over 6 months (P < 0.05). HSCT recipients with hyposalivation pre‐HSCT had higher risk of death (HR: 1.90, 95% CI:1.00‐3.60; P = 0.044) within 6 months post‐HSCT compared with recipients without hyposalivation. Hyposalivation pre‐HSCT was associated with a higher DMFT index score (P < 0.05) and a smaller number of teeth (P < 0.005) 24 months post‐HSCT in comparison with those without hyposalivation.

Conclusions

Hyposalivation and caries were associated with a lower rate of survival in HSCT recipients. Additionally, hyposalivation predisposed to deterioration of oral health post‐HSCT.
Lamivudine‐based maintenance antiretroviral therapies in patients living with HIV‐1 with suppressed HIV RNA: derivation of a predictive score for virological failure
Authors: Borghetti A , Moschese D , Cingolani A , Baldin G , Speziale D , Ciccullo A , Lombardi F , Emiliozzi A , Belmonti S , Antinori A , Cauda R , Di Giambenedetto S
Published: June 2019

Objectives

Two‐drug antiretroviral regimens based on lamivudine (3TC) plus either a protease inhibitor (PI) or dolutegravir (DTG) are becoming increasingly popular in switch strategies. Our goal was to derive a predictive score for virological failure (VF).

Methods

We retrospectively analysed data for a cohort of 587 virologically suppressed (HIV RNA < 37 HIV‐1 RNA copies/mL), adult (≥ 18 years old) patients starting lamivudine plus either a boosted PI or dolutegravir. Predictors of VF (defined as a single HIV RNA measurement ≥ 1000 copies/mL or two consecutive HIV RNA measurements ≥ 50 copies/mL) were identified using a multivariate Cox regression model. A ‘weighted’ score was assigned to each variable associated with VF; the discriminative power of the score obtained was expressed as the area under the receiver‐operator characteristic curve (ROC‐AUC).

Results

During a median 2 years of follow‐up time, 35 VFs occurred; predictors of VF were baseline residual HIV RNA between 20 and 36 copies/mL, African ethnicity, ≥ 10 therapeutic lines, the presence of at least one resistance‐associated mutation (RAM) for resistance to current drugs (excluding M184V), a non‐B viral subtype and a baseline CD4 count < 200 cells/μL. A score of 2 was assigned to non‐B viral subtype, 3 to residual viraemia ≥ 20 copies/mL, ≥ 10 previous therapeutic lines and African ethnicity, 4 to baseline CD4 count < 200 cells/μL, and 7 to the presence of at least one RAM (excluding M184V). The ROC‐AUC was 0.67 (95% confidence interval 0.57–0.77).

Conclusions

The presence of at least one RAM, higher residual viraemia and African ethnicity were among the major predictors of VF in our cohort. Studies with larger sample sizes are warranted to improve the predictive value of the derived score.
Determinants of auditor choice: Review of the empirical literature
Authors: Habib Ahsan , Wu Julia , Bhuiyan Md. Borhan Uddin , Sun Xuan (Sean)
Published: June 2019

We synthesize the empirical archival literature on the determinants of auditor choice in an international setting, critique the findings, and offer suggestions for future research. We categorize the determinants into (i) firm‐level ownership variables, (ii) nonownership corporate governance determinants, (iii) economic determinants driven by the risk of information asymmetry, and (iv) country‐level institutional determinants, including legal protection of investors, political connections, and national culture. Our comprehensive review not only enriches the academic literature, but also provides material of considerable interest to investors, practitioners (auditors), and regulators.