bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of the divalent cations zinc and calcium on the structure and mechanics of reconstituted vimentin intermediate filaments
Authors: Wu Huayin , Shen Yinan , Wang Dianzhuo , Herrmann Harald , Goldman Robert D. , Weitz David A.
Published: November 2019

Divalent cations in a concentration-dependent manner behave as effective crosslinkers of intermediate filaments (IFs) such as vimentin IF (VIF). These interactions have been mostly attributed to their multivalency. However, ion-protein interactions often depend on the ion species, and these effects have not been widely studied in IFs. Here we investigate the effects of two biologically important divalent cations, Zn2+ and Ca2+, on VIF network structure and mechanics in vitro. We find that the network structure is unperturbed at micromolar Zn2+ concentrations, but strong bundle formation is observed at a concentration of 100 μM. Microrheological measurements show that network stiffness increases with cation concentration. However, bundling of filaments softens the network. This trend also holds for VIF networks formed in the presence of Ca2+, but remarkably, a concentration of Ca2+ that is two orders higher is needed to achieve the same effect as with Zn2+, which suggests the importance of salt-protein interactions as described by the Hofmeister effect. Furthermore, we find evidence of competitive binding between the two divalent ion species. Hence, specific interactions between VIFs and divalent cations are likely to be an important mechanism by which cells can control their cytoplasmic mechanics.

Significance

Intermediate filaments are key structural elements within cells; they are known to form networks that can be crosslinked by divalent cations, but the interactions between the ions and the filaments are not well understood. By measuring the effects that two divalent cations, zinc and calcium, have on the structure and mechanics of vimentin intermediate filaments (VIFs), we show that although both have concentration-dependent effects on VIFs, much more calcium is needed to achieve the same effect as a small amount of zinc. Furthermore, when mixtures of the ions are present, the results suggest that there is binding competition. Thus, cells may use the presence of different cation species to precisely control their internal mechanical properties.
Emergence of opposite neurons in a decentralized firing-rate model of multisensory integration
Authors: Niu Xueyan , Chau Ho Yin , Lee Tai Sing , Zhang Wen-Hao
Published: November 2019

Multisensory integration areas such as dorsal medial superior temporal (MSTd) and ventral intraparietal (VIP) areas in macaques combine visual and vestibular cues to produce better estimates of self-motion. Congruent and opposite neurons, two types of neurons found in these areas, prefer congruent inputs and opposite inputs from the two modalities, respectively. A recently proposed computational model of congruent and opposite neurons reproduces their tuning properties and shows that congruent neurons optimally integrate information while opposite neurons compute disparity information. However, the connections in the network are fixed rather than learned, and in fact the connections of opposite neurons, as we will show, cannot arise from Hebbian learning rules. We therefore propose a new model of multisensory integration in which congruent neurons and opposite neurons emerge through Hebbian and anti-Hebbian learning rules, and show that these neurons exhibit experimentally observed tuning properties.
Laminin-511 and α6 Integrins Regulate the Expression of CXCR4 to Promote Endothelial Morphogenesis
Authors: Xu Hao , Pumiglia Kevin , LaFlamme Susan E.
Published: November 2019

During angiogenesis, endothelial cells engage components of the extracellular matrix through integrin-mediated adhesion. Endothelial expression of laminin-411 and laminin-511 are known to promote vessel stability. However, little is known about the contribution of these laminins to endothelial morphogenesis. We used two organotypic cell culture angiogenesis assays in conjunction with RNAi approaches to demonstrate that depletion of either the α4 chain of laminin-411 or the α5 chain of laminin-511 from endothelial cells inhibits sprouting and tube formation. Depletion of α6 integrins resulted in similar phenotypes. Gene expression analysis indicated that loss of either laminin-511 or α6 integrins inhibited the expression of CXCR4, a gene previously associated with angiogenic endothelial cells. Pharmacological or RNAi-dependent inhibition of CXCR4 suppressed endothelial sprouting and morphogenesis. Importantly, expression of recombinant CXCR4 rescued endothelial morphogenesis when the α6 integrin expression was inhibited. Additionally, the depletion of α6 integrins from established tubes resulted in the loss of tube integrity and laminin-511. Taken together, our results indicate that α6 integrins and laminin-511 can promote endothelial morphogenesis by regulating the expression of CXCR4 and suggest that the α6-dependent deposition of laminin-511 protects the integrity of established endothelial tubes.

Summary statement

Endothelial-secreted laminin-511 and α6 integrins promote endothelial morphogenesis by regulating the expression of the chemokine receptor, CXCR4. The depletion of α6 integrins from established tubes results in the loss of tube integrity and laminin-511.
Single cell multiomic analysis of T cell exhaustion in vitro
Authors: Corselli Mirko , Saksena Suraj , Nakamoto Margaret , Lomas Woodrow E. , Taylor Ian , Chattopadhyay Pratip K.
Published: November 2019

A key step in the clinical production of CAR-T cells is the expansion of engineered T cells. To generate enough cells for a therapeutic product, cells must be chronically stimulated, which raises the risk of inducing T-cell exhaustion and reducing therapeutic efficacy. As protocols for T-cell expansion are being developed to optimize CAR T cell yield, function and persistence, fundamental questions about the impact of in vitro manipulation on T-cell identity are important to answer. Namely: 1) what types of cells are generated during chronic stimulation? 2) how many unique cell states can be defined during chronic stimulation? We sought to answer these fundamental questions by performing single-cell multiomic analysis to simultaneously measure expression of 39 proteins and 399 genes in human T cells expanded in vitro. This approach allowed us to study – with unprecedented depth - how T cells change over the course of chronic stimulation. Comprehensive immunophenotypic and transcriptomic analysis at day 0 enabled a refined characterization of T-cell maturational states (from naïve to TEMRA cells) and the identification of a donor-specific subset of terminally differentiated T-cells that would have been otherwise overlooked using canonical cell classification schema. As expected, T-cell activation induced downregulation of naïve-associated markers and upregulation of effector molecules, proliferation regulators, co-inhibitory and co-stimulatory receptors. Our deep kinetic analysis further revealed clusters of proteins and genes identifying unique states of activation defined by markers temporarily expressed upon 3 days of stimulation (PD-1, CD69, LTA), markers constitutively expressed throughout chronic activation (CD25, GITR, LGALS1), and markers uniquely up-regulated upon 14 days of stimulation (CD39, ENTPD1, TNFDF10). Notably, different ratios of cells expressing activation or exhaustion markers were measured at each time point. These data indicate high heterogeneity and plasticity of chronically stimulated T cells in response to different kinetics of activation. In this study, we demonstrate the power of a single-cell multiomic approach to comprehensively characterize T cells and to precisely monitor changes in differentiation, activation and exhaustion signatures in response to different activation protocols.
Chromosome painting does not support a sex chromosome turnover in Lacerta agilis Linnaeus, 1758
Authors: Lisachov Artem P. , Giovannotti Massimo , Pereira Jorge C. , Andreyushkova Daria A. , Romanenko Svetlana A. , Ferguson-Smith Malcolm A. , Borodin Pavel M. , Trifonov Vladimir A.
Published: November 2019

Reptiles show a remarkable diversity of sex determination mechanisms and sex chromosome systems, derived from different autosomal pairs. The origin of the ZW sex chromosomes of Lacerta agilis, a widespread Eurasian lizard species, is a matter of discussion: is it a small macrochromosome from the 11-18 group, common to all lacertids, or this species has unique ZW pair derived from the large chromosome 5. Using independent molecular cytogenetic methods, we investigated the karyotype of L. agilis exigua from Siberia, Russia, to identify the sex chromosomes. FISH with the flow-sorted chromosome painting probe, derived from L. strigata and specific to chromosomes 13, 14, and Z, confirmed that the Z chromosome of L. agilis is a small macrochromosome, the same as in L. strigata. FISH with the telomeric probe showed an extensive accumulation of the telomeric repeat on the W chromosome in agreement with previous studies, excluding the possibility that the lineages of L. agilis studied in different works could have different sex chromosome systems due to a putative intra-species polymorphism. Our results reinforce the idea of the stability of the sex chromosomes and lack of evidence for sex-chromosome turnovers in known species of Lacertidae.
Nonlinear mechanics of lamin filaments and the meshwork topology build an emergent nuclear lamina
Authors: Sapra K. Tanuj , Qin Zhao , Dubrovsky-Gaupp Anna , Aebi Ueli , Müller Daniel J. , Buehler Markus , Medalia Ohad
Published: November 2019

The nuclear lamina – a meshwork of intermediate filaments termed lamins – functions as a mechanotransduction interface between the extracellular matrix and the nucleusviathe cytoskeleton. Although lamins are primarily responsible for the mechanical stability of the nucleus in multicellular organisms,in situcharacterization of lamin filaments under tension has remained elusive. Here, we apply an integrative approach combining atomic force microscopy, cryo-electron tomography, network analysis, and molecular dynamics simulations to directly measure the mechanical response of single lamin filaments in its three-dimensional meshwork. Endogenous lamin filaments portray non-Hookean behavior – they deform reversibly under a force of a few hundred picoNewtons and stiffen at nanoNewton forces. The filaments are extensible, strong and tough, similar to natural silk and superior to the synthetic polymer Kevlar®. Graph theory analysis shows that the lamin meshwork is not a random arrangement of filaments but the meshwork topology follows ‘small world’ properties. Our results suggest that the lamin filaments arrange to form a robust, emergent meshwork that dictates the mechanical properties of individual lamin filaments. The combined approach provides quantitative insights into the structure-function organization of laminsin situ, and implies a role of meshwork topology in laminopathies.
Predicting memory formation over multiple study episodes
Authors: Sievers Carolin , Bird Chris M. , Renoult Louis
Published: November 2019

Repeated study typically improves episodic memory performance. Two different types of explanations of this phenomenon have been put forward: (1) reactivating the same representations strengthens and stabilizes memories, or (2) greater encoding variability benefits memory by promoting richer traces. The present experiment directly compared these predictions in a design with multiple repeated study episodes, allowing to dissociate memory for studied items and their context of study. Participants repeatedly encoded names of famous people four times, either in the same task, or in different tasks. During the test phase, an old/new judgment task was used to assess item memory, followed by a source memory judgment about the encoding task. Consistent with predictions from the encoding variability view, encoding stimulus in different contexts resulted in higher item memory. In contrast, consistent with the reactivation view, source memory performance was higher when participants encoded stimuli in the same task repeatedly. Taken together, our findings indicate that encoding variability benefits episodic memory, by increasing the number of items that are recalled. These benefits are however at the expenses of source recollection and memory for details, which are decreased, likely due to interference and generalization across contexts.
Foreign direct investment and economic growth nexus in Africa
Authors: Hagan Edmond , Amoah Anthony
Published: November 2019

Purpose

African countries are generally fragile. This and other related characteristics affect the potential for growth and development. The purpose of this paper is to investigate whether the effect of FDI on economic growth is contingent on a financial system that accounts for financial market fragility. An important point of departure from earlier studies is the adoption of a new measure of financial market fragility.

Design/methodology/approach

Given the uniqueness of the data set, the study uses a panel data and estimates an econometric model using an instrumental variable approach. For robustness purposes, a pooled ordinary least square is also estimated.

Findings

The study provides evidence that if the financial market is fragile as in the case of Africa, FDI inflows may have a marginally significant positive impact on economic growth. The findings suggest that fragility in the financial market is a key absorptive capacity and cannot be trivialised when exploring FDI–growth nexus in Africa.

Research limitations/implications

The uniqueness of the data set limited the time period of the study. Nonetheless, the findings are still crucial to policy makers in Africa and other developing countries with similar characteristics.

Originality/value

To the best of the authors’ knowledge, this is the first study in Africa to investigate the FDI–growth nexus which accounts for financial market fragility.
Audit committee chairman characteristics and earnings management
Authors: Al-Absy Mujeeb Saif Mohsen , Ku Ismail Ku Nor Izah , Chandren Sitraselvi
Published: November 2019

Purpose

The purpose of this paper is to examine the influence of the characteristics of audit committee chairman (ACC) (tenure, age, gender, ethnicity, accounting expertise and directorship) on earnings management (EM) practices.

Design/methodology/approach

The Jones model and modified Jones model by Dechowet al.(1995) were used to determine the discretionary accruals (DA) of 288 Malaysian listed firms with lowest positive earnings for the years 2013‒2015.

Findings

The results of the ordinary least squares regression indicate that only tenure, gender and ethnicity of the ACC are associated with DA. A further test was conducted by dividing firms into two groups: firms whose boards are chaired by a family member and firms whose boards are chaired by a non-family member. The results reveal that it is possible for firms whose boards are chaired by family members to cause the corporate governance (CG) mechanisms, particularly the audit committee, to lose their effectiveness in overcoming the EM problem. In addition, robustness tests were conducted by using panel data regression, where the results were found to be similar to the original regression results.

Originality/value

This study alerts policymakers, firms and their stakeholders, as well as researchers, regarding the importance of having an independent board chairman, who has no relationship with any directors or major shareholders, as this may hinder the effectiveness of CG mechanisms in curbing EM, especially in emerging countries, such as Malaysia, where it is very difficult to stop members of the family from becoming board directors.
Job preservation efforts: when does job insecurity prompt performance?
Authors: Koen Jessie , Low Jasmine T.H. , Van Vianen Annelies
Published: November 2019

Purpose

While job insecurity generally impedes performance, there may be circumstances under which it can prompt performance. The purpose of this paper is to examine a specific situation (reorganization) in which job insecurity may prompt task and contextual performance. The authors propose that performance can represent a job preservation strategy, to which employees may only resort when supervisor-issued ratings of performance are instrumental toward securing one’s job. The authors hypothesize that because of this instrumentality, job insecurity will motivate employees’ performance only when they have low intrinsic motivation, and only when they perceive high distributive justice.

Design/methodology/approach

In a survey study among 103 permanent employees of a company in reorganization, the authors assessed perceived job insecurity, intrinsic motivation and perceived distributive justice. Supervisors rated employees’ overall performance (task performance and organizational citizenship behaviors).

Findings

Multilevel analyses showed that job insecurity was only positively related to supervisor-rated overall performance among employees with low intrinsic motivation and, unexpectedly, among employees who experienced low distributive justice. Results were cross-validated using employees’ self-rated performance, replicating the findings on distributive justice but not the findings on intrinsic motivation.

Research limitations/implications

The results can inform future research on the specific situations in which job insecurity may prompt job preservation efforts, and call for research to uncover the mechanisms underlying employees’ negative and positive responses to job insecurity. The results and associated implications of this study are largely based on conceptual evidence. In addition, the cross-sectional design warrants precaution about drawing causal inferences from the data.

Originality/value

By combining insights from coping responses and threat foci, this study advances the understanding of when and why job insecurity may prompt performance.
Public-space tactical intervention as urban tourist allure
Authors: Gkoumas Aristeidis , D’Orazio Federico
Published: November 2019

Purpose

The purpose of this paper is to analyze the art-based project of Full Llove Inn as a tactical urbanism intervention and urban tourist attraction. The project consisted of an elevated room-car, displayed in the public space of Amsterdam from August 2006 to September 2007.

Design/methodology/approach

The research was conducted between December 2017 and November 2018 in Amsterdam. The study applied the methodological tools of semi-structured interviews, textual analysis and participatory observation.

Findings

Full Llove Inn provided an extraordinary allure for visitors and residents. It created a sense of intra-personal and inter-personal existential authenticity for local and non-local guests, respectively, while introducing a pop-up hotel as a new form of tactical initiative.

Research limitations/implications

Due to the inability to contact non-local guests for interviews, the only source of data was based on tourist experiences about Full Llove Inn derived from the hotel guest book.

Practical implications

The research suggests that pop-up hotels may be used by Destination Management Organizations as a means of strengthening the brand image and creating a competitive edge for cities.

Social implications

The research indicates that art-inspired tactical interventions in the public space of civic environments could constitute a social capital while generating interactions between residents and visitors.

Originality/value

For the first time in the tourism literature, this study investigates the impact of tactical projects on destination branding from the perspective of both locals and visitors.
Conceptualizing information work for health contexts in Library and Information Science
Authors: Dalmer Nicole K. , Huvila Isto
Published: November 2019

Purpose

The purpose of this paper is to suggest that a closer consideration of the notion of work and, more specifically, information work as a sensitizing concept in Library and Information Science (LIS) can offer a helpful way to differently consider how people interact and engage with information and can complement a parallel focus on practices, behaviours and activities.

Design/methodology/approach

Starting with the advent of the concept of information work in Corbin and Strauss’ work, the paper then summarizes how information work has evolved and taken shape in LIS research and discourse, both within and outside of health-related information contexts.

Findings

The paper argues that information work affords a lens that can acknowledge the multiple levels of effort and multiple processes (cognitive, physical or social-behavioural) related to information activities. This paper outlines six affordances that the use of information work within LIS scholarship imparts: acknowledges the conceptual, mental and affective; brings attention to the invisibility of particular information activities and their constituents; opens up and distinguishes the many different lines of work; destabilizes hierarchies between professionals and non-professionals; emphasizes goals relating to information activities and their underlying pursuits; and questions work/non-work dichotomies established in existing LIS models.

Originality/value

This paper is a first in bringing together the many iterations of information work research in LIS. In doing so, this paper serves as a prompt for other LIS scholars to take up, challenge the existing borders of, and thus advance the concept of information work.
Heterogeneous utility from a representative agent model: immigrants vs non-immigrants
Authors: Phillips Kerk L.
Published: November 2019

Purpose

The purpose of this paper is to infer the welfare of heterogeneous agents using a representative agent model.

Design/methodology/approach

It does so by partitioning the household into subunits and allocating consumption to each subunit proportionally to the income the subunit generates through wages and capital returns.

Findings

The author shows that for a simple dynamic general equilibrium model with immigration, the steady state utilities of these subunits correspond very closely to the utilities for an equivalent heterogeneous agent model. This is particularly true when labor–leisure decisions are made using slightly modified Euler equations.

Originality/value

More complicated models can be solved and simulated using fewer computational resources using this technique.
The role of tourism in island economic growth and resilience
Authors: Mazzola Fabio , Pizzuto Pietro , Ruggieri Giovanni
Published: November 2019

Purpose

The purpose of this paper is to verifying the economic resilience of islands and, in particular, the role of the tourism sector in the reaction to the most recent economic crisis. The analysis concerns insular contexts, such as the greater island regions in the Mediterranean basin.

Design/methodology/approach

Static and dynamic panel data techniques are used for a sample of 13 island economies over a period of 16 years.

Findings

Results show that the growth factors for regional islands are similar to the ones usually considered for other regions, but the tourism-led growth hypothesis is highly supported. Tourism demand more than supply plays a role together with accessibility. The crisis has reduced the importance of tourism supply, while tourism demand and accessibility have remained crucial for growth together with other traditional engines of growth.

Originality/value

To the best of authors’ knowledge, none of the current works has considered territorial determinants and tourism indicators inside the same framework analyzing growth in island economies by considering the changes occurred during the crisis explicitly.
The derivation of Shariah risk in Islamic finance: a theoretical approach
Authors: Mohd Noor Nurul Syazwani , Mohd. Shafiai Muhammad Hakimi , Ismail Abdul Ghafar
Published: November 2019

Purpose

This paper aims to propose a derivation of Shariah risk from both the Islamic finance theory and theory of contracts in Islamic law. Specifically, it deliberates the derivation of Shariah risk following the contracts validity and apprises the readers of the Shariah risk issues currently under debate.

Design/methodology/approach

This study reviews the relevant literature and presents an analysis of contract rulings through evidence derived from the Qur’an, Hadith and other secondary sources of Islamic law. Various theories of Islamic finance and Islamic law of contracts are identified, to examine the general principles and essential elements and conditions of a valid contract.

Findings

This analysis asserts that any circumstances that may render invalidity of the contract will trigger Shariah risk. More importantly, this paper highlights the implications of invalid contracts, based on the opinion of Hanafi jurists, who concluded that Shariah risk may be derived from any void or voidable contracts due to the failure of the contractual parties to comply with Shariah contractual obligations.

Research limitations/implications

This paper emphasises the derivation of Shariah risk over theoretical approaches. It does not include an explanation in the form of any empirical model.

Originality/value

This is the first study that contributes to the field of derivation of Shariah risk, based on the theory from the Islamic law of contracts.
The school as a learning organisation in China
Authors: Tan Charlene
Published: November 2019

Purpose

The purpose of this paper is to respond to a recent article published in this journal by Stoll and Kools (2017) on the “School as a Learning Organisation” (SLO). It critiques Stoll and Kools’ integrated model of a SLO by investigating whether the model can be applied to a specific socio-cultural schooling context using the example of mainland China.

Design/methodology/approach

This paper reviews the extant published works on SLO with a focus on Stoll and Kools’ integrated model of a SLO. The paper also reviews the existing literature on schooling practices in China.

Findings

It is argued that the application of Stoll and Kools’ integrated model of a SLO in China needs to take into consideration and incorporate the prevailing centralised, hierarchical and collective characteristics in the country.

Research limitations/implications

The paper questions the universal application of the seven action-oriented dimensions of the SLO for all schools regardless of socio-cultural contexts. It highlights the mediating and moderating effects of local histories, conditions and developments when promoting SLO in a specific learning site.

Practical implications

Policymakers, researchers and educators need to contextualise the ideal of the SLO by interpreting and appropriating it in ways that are compatible with the dominant socio-cultural norms and practices in a particular locality.

Originality/value

This paper fills a current gap by relating the notion of SLO model to the schooling settings in China. It offers a collective slant to SLO that is tailored for the educational realities and experiences in China.
Mediation effects of service features on rapport–dependency link in emerging market
Authors: Fatima Johra Kayeser , di Mascio Rita , Johns Raechel , Quazi Ali
Published: November 2019

Purpose

The purpose of this paper is to explore the mediation impacts of core, relational and tangible service-quality features on the relationship between customer–frontline employee rapport and customer dependency in an emerging market context. The study examines the moderating effects of relationship age and frequency of customers’ physical visits.

Design/methodology/approach

Partial least squares-based structural equation modelling was used to analyse data from a survey of 290 financial services customers in Dhaka, Bangladesh using the convenience sampling technique.

Findings

Results show that relational service-quality features had the largest mediation impact on the rapport–dependency relationship, followed by core and tangible service-quality features. Relationship age was not found to be a significant moderator for any relationship. However, the moderation effect of the frequency of customers’ physical visits to the service premises was significant, but only for the link between relational service-quality features and customer dependency and not for the other two types of service-quality features.

Research limitations/implications

Data collected from several other emerging markets would provide more rigorous findings: this is recommended as an avenue for further research.

Practical implications

Practitioners can manipulate specific relational or tangible service-quality features to increase customer dependency on their firms, thus ensuring longer-term customer retention.

Originality/value

This study is the first one to examine the relative significance of the impacts of relational features vs tangible features of services on customer dependency in the emerging market context, with rapport serving as an antecedent.
Dealing with temporariness
Authors: Sobral Filipa , Ng Eddy S. , Castanheira Filipa , Chambel Maria José , Koene Bas
Published: November 2019

Purpose

A major trend in the changing nature of work is the increasing use of temporary workers. Although common among students, older employees have joined the ranks of temporary workers as they extend their work lives. Temporary workers tend to report lower affective commitment and consequently poorer work outcomes. However, different generations of workers may conceive temporary work differently from each other. The purpose of this paper is to explore how different generations of temporary workers, respond to human resource practices (HRP), which in turn influences their affective commitment and work performance.

Design/methodology/approach

The sample is comprised of 3,876 temporary agency workers (TAWs) from seven temporary employment agencies in Portugal. The authors undertook multiple group SEM analyses to test a moderated mediation model that accounts for TAWs’ affective commitment (toward the agency and the client company) across three generations (Baby Boomers, Generation X and Millennials) in the relationship between human resources practices and overall perceived performance.

Findings

After controlling for gender, age and tenure, the authors find generational differences in the perceptions of HRP and perceived performance. The results support the moderator effect of generations in the direct and indirect relationships – through both affective commitments – between TAWs’ perceived HRP and perceived performance.

Research limitations/implications

The cross-sectional design limits the possibility to make causal inferences.

Originality/value

This study contributes to a better understanding of how different generations respond to temporary employment relationships. The findings suggest important differences in the way in which the same HRP system relates (directly and indirectly thorough affective commitment toward the client) with their perceived performance across different generations.
Bibliometric study on dividend policy
Authors: Pinto Geetanjali , Rastogi Shailesh , Kadam Sanjeev , Sharma Arpita
Published: November 2019

Purpose

The purpose of this paper is to study the general trends in the area of dividend policy which will help to identify fertile research streams in this area with a potential for further investigation.

Design/methodology/approach

To conduct a systematic literature review, the authors use a three-step methodology to collect resources and thus evaluate the research work done in the area of dividend policy. First, the necessary data are extracted from the Scopus database using the relevant keywords. The initial search results are then narrowed down to include only English language journal publications which are stored in the file. Finally, this file is used as primary data for data analysis. Data analysis is done using bibliometric and network analysis tools to recognize the trends in dividend policy to help researchers identify emergent areas for future work to be done.

Findings

This study reveals that research in the area of dividend policy is rapidly expanding since 2005; affiliation statistics show that majority of the publications are done in the USA and the UK; and many questions linked to dividend decision remain unanswered, especially in respect of emerging markets.

Originality/value

There is a need to organize the literature and understand the different areas that have been explored by many researchers. This study attempts to recognize the important research studies, determine the current areas of research attention, provide an understanding for current research interest and provide guidelines for future studies in the area of dividend policy.
The heterogeneous implementation of ISO 9001 in service-oriented organizations
Authors: Chountalas Panos T. , Magoutas Anastasios I. , Zografaki Eleni
Published: November 2019

Purpose

The purpose of this paper is to investigate the heterogeneity in the implementation of the ISO 9001 quality management system in service-oriented organizations, and to identify patterns (i.e. relationships, dependencies and exceptions) among critical implementation factors, possible implementation determinants and desired post-implementation outcomes.

Design/methodology/approach

The paper adopts a qualitative approach, in the form of a multiple case study of five ISO 9001 certified, service-oriented organizations, located in Greece. Using multiple data collection methods including interviews with upper management and employees, desk research and on-site observation allowed for data triangulation.

Findings

The analysis reveals that ISO 9001 implementation can range across different levels of fidelity, from merely superficial to genuinely substantive. Several determinants (i.e. implementation experience, motivation for certification, perception of quality, commitment to change) affect the level of fidelity and, in turn, the post-implementation outcomes. Interestingly, even a superficial ISO 9001 implementation can initiate, at least to a moderate degree, beneficial changes throughout the organizations. The organizations that strictly abide by ISO 9001 requirements still have to address some challenges, most notably to instill a culture of prevention in their management system and to efficiently balance standardization and flexibility.

Originality/value

This study contributes to the ISO 9001 internalization literature, providing an in-depth analysis of possible patterns among ISO 9001 implementation factors, determinants and outcomes. Related findings are also discussed under the prism of the revised ISO 9001:2015.
Integrated internal audit in management system
Authors: Hassan Noor Aishah , Mohamad Zailani Suhaiza Hanim , Hasan Haslida Abu
Published: November 2019

Purpose

The purpose of this paper is to investigate the implementation of integrated internal audit management (IIAM) and compare the implementation of IIAM by Malaysian firms with different certifications (ISO 9001, ISO 14001 and OHSAS 18001).

Design/methodology/approach

This study involves three studies on the implementation of integrated internal audit processes. Furthermore, this study compares the implementation of the audit in the selected firms. The qualitative research methodology was adopted to analyse the data.

Findings

This study is an exploratory study and the findings indicate the differences between the implementation of the internal audit process across different firms. All the firms are highly motivated and demonstrate resource management whilst implementing the IIAM while firms experiencing the same difficulties. The study also found that all of the firms are enjoying similar benefits.

Research limitations/implications

The scope of this research paper is limited to three Malaysian manufacturing firms with different quality certifications: ISO 9001, ISO 14001 and OHSAS 18001. Thus, the finding cannot be generalised to all firms in Malaysia. However, the findings are significant as they present an interesting comparison between the implementation of IIAM by manufacturing firms in Malaysia.

Originality/value

Although the integration of management systems has been analysed many times, this study focussed on the comparison of firms’ practices of the IIAM.
Influence of chemically radiative nanoparticles on flow of Maxwell electrically conducting fluid over a convectively heated exponential stretching sheet
Authors: Ray Atul Kumar , B. Vasu
Published: November 2019

Purpose

This paper aims to examine the influence of radiative nanoparticles on incompressible electrically conducting upper convected Maxwell fluid (rate type fluid) flow over a convectively heated exponential stretching sheet with suction/injection in the presence of heat source taking chemical reaction into account. Also, a comparison of the flow behavior of Newtonian and Maxwell fluid containing nanoparticles under the effect of different thermophysical parameters is elaborated. Velocity, temperature and nanoparticle volume fractions are assumed to have exponential distribution at boundary. Buongiorno model is considered for nanofluid transport.

Design/methodology/approach

The equations, which govern the flow, are reduced to ordinary differential equations using suitable transformation. The transformed equations are solved using a robust homotopy analysis method. The convergence of the homotopy series solution is explicitly discussed. The present results are compared with the results reported in the literature and are found to be in good agreement.

Findings

It is observed from the present study that larger relaxation time leads to slower recovery, which results in a decrease in velocity, whereas temperature and nanoparticle volume fraction is increased. Maxwell nanofluid has lower velocity with higher temperature and nanoparticle volume fraction when compared with Newtonian counterpart. Also, the presence of magnetic field leads to decrease the velocity of the nanofluid and enhances the skin coefficient friction. The existence of thermal radiation and heat source enhance the temperature. Further, the presence of chemical reaction leads to decrease in nanoparticle volume fraction. Higher value of Deborah number results in lower the rate of heat and mass transfer.

Originality/value

The novelty of present work lies in understanding the impact of fluid elasticity and radiative nanoparticles on the flow over convectively heated exponentially boundary surface in the presence of a magnetic field using homotopy analysis method. The current results may help in designing electronic and industrial applicants. The present outputs have not been considered elsewhere.
Surface indicators are correlated with soil multifunctionality in global drylands
Authors: Eldridge David J. , Delgado‐Baquerizo Manuel , Quero José L. , Ochoa Victoria , Gozalo Beatriz , García‐Palacios Pablo , Escolar Cristina , García‐Gómez Miguel , Prina Aníbal , Bowker Mathew A. , Bran Donaldo E. , Castro Ignacio , Cea Alex , Derak Mchich , Espinosa Carlos I. , Florentino Adriana , Gaitán Juan J. , Gatica Gabriel , Gómez‐González Susana , Ghiloufi Wahida , Gutierrez Julio R. , Gusmán-Montalván Elizabeth , Hernández Rosa M. , Hughes Frederic M. , Muiño Walter , Monerris Jorge , Ospina Abelardo , Ramírez David A. , Ribas‐Fernández Yanina A. , Romão Roberto L. , Torres‐Díaz Cristian , Koen Terrance B. , Maestre Fernando T.
Published: November 2019

Multiple ecosystem functions need to be considered simultaneously to manage and protect the several ecosystem services that are essential to people and their environments. Despite this, cost effective, tangible, relatively simple and globally relevant methodologies to monitor in situ soil multifunctionality, that is, the provision of multiple ecosystem functions by soils, have not been tested at the global scale.

We combined correlation analysis and structural equation modelling to explore whether we could find easily measured, field‐based indicators of soil multifunctionality (measured using functions linked to the cycling and storage of soil carbon, nitrogen and phosphorus). To do this, we gathered soil data from 120 dryland ecosystems from five continents.

Two soil surface attributes measured in situ (litter incorporation and surface aggregate stability) were the most strongly associated with soil multifunctionality, even after accounting for geographic location and other drivers such as climate, woody cover, soil pH and soil electric conductivity. The positive relationships between surface stability and litter incorporation on soil multifunctionality were greater beneath the canopy of perennial vegetation than in adjacent, open areas devoid of vascular plants. The positive associations between surface aggregate stability and soil functions increased with increasing mean annual temperature.

Synthesis and applications. Our findings demonstrate that a reduced suite of easily measured in situ soil surface attributes can be used as potential indicators of soil multifunctionality in drylands world‐wide. These attributes, which relate to plant litter (origin, incorporation, cover), and surface stability, are relatively cheap and easy to assess with minimal training, allowing operators to sample many sites across widely varying climatic areas and soil types. The correlations of these variables are comparable to the influence of climate or soil, and would allow cost‐effective monitoring of soil multifunctionality under changing land‐use and environmental conditions. This would provide important information for evaluating the ecological impacts of land degradation, desertification and climate change in drylands world‐wide.
Mechanisms of soil bacterial and fungal community assembly differ among and within islands
Authors: Wang Pandeng , Li Shao‐Peng , Yang Xian , Zhou Jizhong , Shu Wensheng , Jiang Lin
Published: November 2019

The study of islands has made substantial contributions to the development of evolutionary and ecological theory. However, we know little about microbial community assembly on islands. Using soil microbial data collected from 29 lake islands and nearby mainland, we examined the assembly mechanisms of soil bacterial and fungal communities among and within islands. We found that deterministic processes, especially homogeneous selection, tended to be more important in shaping the assembly of soil bacterial communities among islands, while stochastic processes tended to be more important within islands. Moreover, increasing island area increased the importance of homogeneous selection, but reduced the importance of variable selection, for soil bacterial community assembly within islands. By contrast, stochastic processes tended to dominate soil fungal community assembly both among and within islands, with dispersal limitation playing a more important role within than among islands. Our results highlight the scale‐ and taxon‐dependence of insular soil microbial community assembly, suggesting that spatial scale should be explicitly considered when evaluating the influences of habitat fragmentation on soil microbial communities.
Characterisation of soluble aggregates from commercial whey protein concentrate suspensions: Effect of protein concentration, pH, and heat treatment conditions
Authors: Meza Bárbara E , De Piante Vicín Daniel A , Marino Fernanda , Sihufe Guillermo A , Peralta Juan Manuel , Zorrilla Susana E
Published: November 2019

Soluble aggregates obtained from heat‐treated suspensions of commercial whey protein concentrate with 74.4% w/w protein were characterised. The effect of protein concentration (7 and 8% w/w), pH (7.0, 7.5 and 8.0), and heating time (0, 5, 10, 15, 20 and 30 min) at 80 °C were evaluated. Whey protein concentrate suspensions with the highest protein concentration (8% w/w) and the lowest pH (pH 7.0) had the highest steady shear viscosity and absorbance values, indicating the effect of the soluble aggregate content (high concentration) and the aggregate size (at lower pH values). According to principal component analysis, samples with 8% w/w and pH 7.0 were grouped in a plot region that confirmed the behaviour observed by confocal microscopy. Those whey protein concentrate suspensions could have soluble aggregates with a strong probability of interacting with cations (in cold gelation applications such as microencapsulation) and with each other (in film‐formation during coating).
Evaluation of Agonal Cardiac Function for Sudden Cardiac Death in Forensic Medicine with Postmortem Brain Natriuretic Peptide (BNP) and NT‐proBNP: A Meta‐analysis
Authors: Cao Zhipeng , Zhao Mengyang , Xu Chengyang , Zhang Tianyi , Jia Yuqing , Wang Tianqi , Zhu Baoli
Published: November 2019

Sudden cardiac death (SCD) is an unexpected death caused by a sudden loss of cardiac function, which is currently a global public health problem. Evaluation of the agonal cardiac function of the deceased is a quite important task for the diagnosis of SCD in forensic medicine. Brain natriuretic peptide (BNP) and N‐terminal proBNP (NT‐proBNP) are currently considered as significant biomarkers for the diagnosis of heart failure in both clinical and forensic practices. To investigate the postmortem evaluation roles of postmortem BNP and NT‐proBNP levels for SCD, the present study meta‐analyzed eight related studies from Embase, Cochrane Library, PubMed, China Biomedical Literature Database, China National Knowledge Infrastructure, and Wanfang Data. Newcastle–Ottawa Quality Assessment Scale was used to assess the quality of the included literature, and the meta‐analysis was performed by RevMan 5.3.5 software. Postmortem NT‐proBNP in pericardial fluid showed higher levels in the SCD group than that of the non‐SCD group with the weighted mean difference = 3665.74, 95% confidence interval: 1812.89–5518.59, and p = 0.0001. However, postmortem levels of BNP in pericardial fluid and NT‐proBNP in serum revealed no statistical difference between SCD and non‐SCD subjects. The results of present meta‐analysis demonstrated that postmortem NT‐proBNP in the pericardial fluid could be used as an ancillary indicator for evaluation of agonal cardiac function in forensic medicine.
What is the value of third‐line chemotherapy in advanced gastroesophageal cancer? A 5‐year retrospective analysis at a single center
Authors: Lam Justina Yick Ching , Choo Su Pin , Tai David Wai‐Meng , Tan Iain Bee Huat , Tham Chee Kian , Koo Wen Hsin , Ong Simon Yew Kuang , Ang Soo Fan , Chua Clarinda Wei Ling , Chong Dawn Qingqing , Teo Patrick Tze Hern , Lee Christabel Jing Zhi , Ee Samuel Cheng En , Ng Matthew Chau Hsien
Published: November 2019

Aim

The survival benefit of using a non‐cross resistant second‐line chemotherapy in the third‐line setting in metastatic gastroesophageal cancer is unproven. We evaluated the utility of third‐line chemotherapy in patients treated at a single institution.

Methods

Between 2010 and 2014, efficacy and toxicity data of patients who received three or more lines of systemic therapies for metastatic gastroesophageal adenocarcinoma at the National Cancer Centre Singapore was retrospectively analyzed.

Results

Thirty‐two (6%) patients received three or more lines of chemotherapy. The median age and ECOG performance status were 59 years (36–82) and 1 (0–2), respectively. Majority of patients (88%) had tumor located in the stomach and 13 patients (41%) had diffuse histology or poorly cohesive or signet ring cells. Four (12%) patients had HER2‐positive disease. Prior therapy was platinum (100%), fluoropyrimidine (97%), taxane (63%), irinotecan (28%), anthracycline (13%) and ramucirumab (3%). Third‐line therapy consisted of 24 (75%) monotherapy, 6 (19%) doublet, 1 (3%) triplet chemotherapy and 1 (3%) clinical trial. Monotherapy irinotecan (44%) was most common, followed by docetaxel (19%) and paclitaxel (9%). Of 22 patients evaluable for response, there was 1 (5%) partial response, 9 (41%) stable disease. Median overall survival was 18.3 weeks (4.3–65.1). Of 30 patients evaluable for toxicities, 17 (57%) experienced at least one grade 3 or 4 toxicities.

Conclusion

The benefit of using non‐cross resistant second‐line regimens as third‐line chemotherapy was small with moderate toxicity. Newer agents such as nivolumab or TAS‐102 or clinical trial may be preferred.