bluuebunny/crossref_metadata_2025 huggingface dataset:
Inactivation of the core cheVAWY chemotaxis genes disrupts chemotactic motility and organised biofilm formation in Campylobacter jejuni
Authors: Reuter Mark , Ultee Eveline , Toseafa Yasmin , Tan Andrew , van Vliet Arnoud H.M.
Published: October 2018

Flagellar motility plays a central role in the bacterial foodborne pathogen Campylobacter jejuni, as flagellar motility is required for reaching the intestinal epithelium and subsequent colonisation or disease. Flagellar proteins also contribute strongly to biofilm formation during transmission. Chemotaxis is the process directing flagellar motility in response to attractant and repellent stimuli, but its role in biofilm formation of C. jejuni is not well understood. Here we show that inactivation of the core chemotaxis genes cheVAWY in C. jejuni strain NCTC 11168 affects both chemotactic motility and biofilm formation. Inactivation of any of the core chemotaxis genes (cheA, cheY, cheV or cheW) impaired chemotactic motility but did not affect flagellar assembly or growth. The ΔcheY mutant swam in clockwise loops, while complementation restored normal motility. Inactivation of the core chemotaxis genes interfered with the ability to form a discrete biofilm at the air-media interface, and the ΔcheY mutant displayed reduced dispersal/shedding of bacteria into the planktonic fraction. This suggests that while the chemotaxis system is not required for biofilm formation per se, it is necessary for organized biofilm formation. Hence interference with the Campylobacter chemotaxis system at any level disrupts optimal chemotactic motility and transmission modes such as biofilm formation.
Molecular epidemiology of ColombianHistoplasma capsulatumisolates shows their polyphyletic behavior and point out raw chicken manure as one of the infections sources
Authors: Gómez Luisa F. , Arango Myrtha , McEwen Juan G. , Gómez Oscar M. , Zuluaga Alejandra , Peláeze Carlos A. , Acevedo Jose M. , Taylor María L. , Jiménez María del P.
Published: October 2018

The thermally dimorphic fungusHistoplasma capsulatumis the causative agent of histoplasmosis, which is the most prevalent endemic mycosis in America. The replacement of organic matter in agro-ecosystems is necessary in the tropics, and the use of organic fertilizers has increased. Cases and outbreaks due to the presence of the fungus in these components have been reported. In Colombia, chicken manure is the most common raw material in the organic fertilizers production. In this work, we reached the isolation of the fungus from a chicken manure. Then, we were able to compare genetically 3 environmental isolates with 42 Colombian human clinical isolates. The genetic comparison showed the environmental isolates grouping together with the clinical isolates. This result suggests chicken manure as one of the infection source withH. capsulatum. Also, the phylogenetic analysis using anotherH. capsulatumisolates from databases showed that the Colombian isolates widely distributed in the relation tree. This result pointed out the great genetic diversity amongH. capsulatumColombian population.
Cytologic, Genetic, and Proteomic Analysis of a Yellow Leaf Mutant of Sesame (Sesamum indicumL.),Siyl-1
Authors: Gao Tongmei , Wei Shuangling , Chen Jing , Wu Yin , Li Feng , Wei Libin , Li Chun , Zeng Yanjuan , Tian Yuan , Wang Dongyong , Zhang Haiyang
Published: October 2018

Leaf color mutation in sesame always affects the growth and development of plantlets, and their yield. To clarify the mechanisms underlying leaf color regulation in sesame, we analyzed a yellow-green leaf mutant. Genetic analysis of the mutant selfing revealed 3 phenotypes—YY, light-yellow (lethal);Yy, yellow-green; andyy, normal green—controlled by an incompletely dominant nuclear gene,Siyl-1. InYYandYy, the number and morphological structure of the chloroplast changed evidently, with disordered inner matter, and significantly decreased chlorophyll content. To explore the regulation mechanism of leaf color mutation, the proteins expressed amongYY,Yy, andyywere analyzed. All 98 differentially expressed proteins (DEPs) were classified into 5 functional groups, in which photosynthesis and energy metabolism (82.7%) occupied a dominant position. Our findings provide the basis for further molecular mechanism and biochemical effect analysis of yellow leaf mutants in plants.
Designer Sinorhizobium meliloti strains and multi-functional vectors for direct inter-kingdom transfer of high G+C content DNA
Authors: Brumwell Stephanie L. , MacLeod Michael R. , Huang Tony , Cochrane Ryan , Meaney Rebecca S. , Zamani Maryam , Matysiakiewicz Ola , Janakirama Preetam , Edgell David R. , Charles Trevor C. , Finan Turlough M. , Karas Bogumil J.
Published: October 2018

Storage and manipulation of large DNA fragments is crucial for synthetic biology applications, yet DNA with high G+C content can be unstable in many host organisms. Here, we report the development of Sinorhizobium meliloti as a new universal host that can store DNA, including high G+C content, and mobilize DNA to Escherichia coli, Saccharomyces cerevisiae, and the eukaryotic microalgae Phaeodactylum tricornutum. We deleted the S. meliloti hsdR restriction-system to enable DNA transformation with up to 1.4 x 105 efficiency. Multi-host and multi-functional shuttle vectors (MHS) were constructed and shown to stably replicate in S. meliloti, E. coli, S. cerevisiae, and P. tricornutum, with a copy-number inducible E. coli origin for isolating plasmid DNA. Crucially, we demonstrated that S. meliloti can act as a universal conjugative donor for MHS plasmids with a cargo of at least 62 kb of G+C rich DNA derived from Deinococcus radiodurans.
Assessment of menstrual hygiene management and its determinants among adolescent girls: A cross-sectional study in school adolescent girls in Addis Ababa, Ethiopia
Authors: Biruk Ephrem , Tefera Worku , Tadesse Nardos , Sisay Ashagre
Published: October 2018

Introduction

Managing menstruation is essentially dealing with menstrual flow and also in continuing regular activities like going to school, working etc. However, menstruation can place significant obstacles in girls’ access to health, education and future prospects if they are not equipped for effective menstrual hygiene management.

Objective

To assess the menstrual hygiene management and its determinant among school girls in Addis Ababa, Ethiopia.

Methods

Cross-sectional study design with quantitative method was carried out among 770 systematically selected adolescent school girls of Addis Ababa from April 1 to May 5, 2017. A self-administered pre-test close ended Amharic questionnaire at school setting was used for data collection. The coding was done using the original English version and entered to EPI-7 software. The quantitative file exported to statistical package for social science (SPSS) version 25.0 software for analysis. Total mean score was used to categorize individuals as good and poor while AOR; 95% CI with p < 0.05 was used to determine factors of menstrual hygiene management practice.

Result

This study had 98% response rate. 530 (70.1%) and 388(51.3%) respondents had good knowledge and practice of menstrual hygiene respectively. The findings also showed a significant positive association between good knowledge of menstruation and girls from mother’s whose education were secondary (AOR = 10.012, 95 % CI = 3.628-27.629). Wealth index quantile five (AOR = 9.038, 95 % CI = 3.728-21.909) revealed significant positive association with good practice of menstrual hygiene.

Conclusion and recommendation

Majority of participants had good knowledge and practice of menstrual hygiene and majority of them were from private school. Although knowledge was better than practice, girls should be educated about the process, use of proper pads or absorbents and its proper disposal.
Timing and causes of the distribution pattern of Oncomelania hupensis estimated by molecular and geologic data
Authors: Ji Wen-bin , Xu Shu-xin , Bai Jun , Cui Ying-yi , Zhou Xian-min , Zou Jie-xin
Published: October 2018

As the only intermediate host of Schistosoma japonicum, Oncomelania hupensis plays an irreplaceable role in the prevalence of schistosomiasis japonica. Several living subspecies of Oncomelania hupensis are found in Asia, especially in China, Japan,the Philippines, and Sulawesi of Indonesia. The existing geographical distribution pattern of O. hupensis has been influenced by geological events. This study used existing mitochondrial gene data for O. hupensis in the GenBank database and the molecular clock method to estimate the divergence time of each subspecies of O. hupensis. For the first time, the timing and causes of the distribution pattern of the different O. hupensis subspecies were studied by combining molecular data with data on geologic events. The results showed that the uplift and isolation of the Qinghai-Tibet Plateau caused Oncomelania hupensis robertsoni to differentiate 4.76 Ma(Million anniversary), while Oncomelania hupensis guangxiensis was affected by the third Himalayan orogenic movement, differentiating 1.10 Ma. Oncomelania hupensis nosophora was influenced by the formation of the Yonaguni Strait and diverged 1.43 Ma. Influenced by ice ages and interglacial periods, Oncomelania hupensis tangi and Oncomelania hupensis formosana diverged 0.57 Ma. The link of the ancient Yangtze River promoted the spread of O. hupensis to the middle and lower reaches of the Yangtze River, and the developed water network facilitated gene exchange among Oncomelania hupensis hupensis in the area. Eventually, 0.62 Ma, O. h. hupensis differentiated.

Author summary

Phylogenetic analysis of Pomatiopsidae species showed that Oncomelania was isolated from other genera and clustered independently in phylogenetic trees. Further analysis of the species Oncomelania hupensis and its subspecies was performed. The snail species O. hupensis has multiple subspecies that exhibit certain differences. These subspecies are distributed across Asia, from China’s Yunnan Province in the west to Japan in the east and south to the Philippines and Indonesia. In addition, the subspecies are widespread in the middle and lower reaches of the Yangtze River in China, and the distribution ranges of the different subspecies do not overlap. The formation of this distribution pattern of each subspecies of O. hupensis has a profound impact on the prevalence of Schistosoma japonicum. Therefore, the authors analyzed molecular data and geological historical events to investigate the timing and causes of the distribution pattern of each subspecies of O. hupensis.
Massively parallel fitness profiling reveals multiple novel enzymes inPseudomonas putidalysine metabolism
Authors: Thompson Mitchell G. , Blake-Hedges Jacquelyn M. , Cruz-Morales Pablo , Barajas Jesus F. , Curran Samuel C. , Eiben Christopher B. , Harris Nicholas C. , Benites Veronica T. , Gin Jennifer W. , Sharpless William A. , Twigg Frederick F. , Skyrud Will , Krishna Rohith N. , Pereira Jose Henrique , Baidoo Edward E. K. , Petzold Christopher J. , Adams Paul D. , Arkin Adam P. , Deutschbauer Adam M. , Keasling Jay D.
Published: October 2018

Despite intensive study for 50 years, the biochemical and genetic links between lysine metabolism and central metabolism inPseudomonas putidaremain unresolved. To establish these biochemical links, we leveraged Random Barcode Transposon Sequencing (RB-TnSeq), a genome-wide assay measuring the fitness of thousands of genes in parallel, to identify multiple novel enzymes in both L- and D-lysine metabolism. We first describe three pathway enzymes that catabolize L-2-aminoadipate (L-2AA) to 2-ketoglutarate (2KG), connecting D-lysine to the TCA cycle. One of these enzymes, PP_5260, contains a DUF1338 domain, a family with no previously described biological function. Our work also identified the recently described CoA independent route of L-lysine degradation that metabolizes to succinate. We expanded on previous findings by demonstrating that glutarate hydroxylase CsiD is promiscuous in its 2-oxoacid selectivity. Proteomics of select pathway enzymes revealed that expression of catabolic genes is highly sensitive to particular pathway metabolites, implying intensive local and global regulation. This work demonstrates the utility of RB-TnSeq for discovering novel metabolic pathways in even well-studied bacteria, as well as a powerful tool for validating previous research.

Importance

P. putidalysine metabolism can produce multiple commodity chemicals, conferring great biotechnological value. Despite much research, connecting lysine catabolism to central metabolism inP. putidaremained undefined. Herein we use Random Barcode Transposon Sequencing to fill in the gaps of lysine metabolism inP. putida. We describe a route of 2-oxoadipate (2OA) catabolism in bacteria, which utilizes DUF1338 containing protein PP_5260. Despite its prevalence in many domains of life, DUF1338 containing proteins had no known biochemical function. We demonstrate PP_5260 is a metalloenzyme which catalyzes an unusual 2OA to D-2HG decarboxylation. Our screen also identified a recently described novel glutarate metabolic pathway. We validate previous results, and expand the understanding of glutarate hydroxylase CsiD by showing can it use either 2OA or 2KG as a cosubstrate. Our work demonstrates biological novelty can be rapidly identified using unbiased experimental genetics, and that RB-TnSeq can be used to rapidly validate previous results.
Phosphorus K-edge XANES spectroscopy has probably often underestimated iron oxyhydroxide-bound P in soils
Authors: Prietzel Jörg , Klysubun Wantana
Published: October 2018

Phosphorus (P) K-edge X-ray absorption near-edge structure (XANES) spectra of orthophosphate (oPO4) bound to soil FeIII minerals (e.g. ferrihydrite, goethite) show a pre-edge signal at 2148–2152 eV. It is unknown whether organic P bound to FeIII oxyhydroxides also show this feature. Otherwise, Fe-bound soil P may be underestimated by P K-edge XANES spectroscopy, because a large portion of Fe oxyhydroxide-bound P in soils is organic P. K-edge XANES spectra were obtained for different organic P compounds present in soils [inositol hexaphosphate (IHP), glucose-6-phosphate (G6P), adenosine triphosphate (ATP)] after sorption to ferrihydrite or goethite and compared with spectra of oPO4 adsorbed to these minerals. P sorption to ferrihydrite increased in the sequence IHP ≪ G6P < oPO4 < ATP. P sorption to goethite increased in the sequence G6P < oPO4 ≪ ATP = IHP. Pre-edge signals in P K-edge XANES spectra of organic P adsorbed to Fe oxyhydroxides were markedly smaller compared with those of oPO4 adsorbed to these minerals and absent for FeIII oxyhydroxide-bound ATP as well as goethite-bound IHP. Linear combination fitting (LCF) performed on spectra of IHP, G6P or ATP adsorbed to ferrihydrite or goethite, using only spectra of FeIII oxyhydroxide-bound oPO4 as reference compounds for Fe-bound P, erroneously assigned >93% (ferrihydrite) or >41% (goethite) of Fe-bound P to non-Fe-bound P species. Inclusion of FeIII oxyhydroxide-bound IHP as reference compounds markedly increased the recovery of oxyhydroxide-bound organic P. Thus, Fe-bound soil P has probably often been underestimated by LCF in soil XANES studies where IHP adsorbed to ferrihydrite and to goethite were not included as reference compounds.
Control and monitoring assistant for pilot
Authors: Pieniazek Jacek
Published: October 2018

Purpose

Cooperation of a pilot with an automated aircraft control and monitoring systems is a problem which should be solved designing the whole system. The method of design, which creates an assistant of a pilot, is the purpose of this study.

Design/methodology/approach

An analysis of human factors shows demands for working environment. An integration method for various technological systems and algorithms is searched.

Findings

It is possible to make the whole system to become a pilot assistant, which has ability to exchange information with pilot by a dialogue. Structural flexibility is obtained in multi-agent system structure.

Practical implications

Proposed approach is a solution of how to integrate increasing amount of aircraft systems. It is expected that new form of cooperation fits to human features. Proposed methodology solves problem of simultaneous control by two controllers and cooperative making decisions.

Social implications

Dialogue between human and the system proposed in this solution will change perception of machines.

Originality/value

New abilities of machines and proposition of their realisation are presented. Presented solution of simultaneous control and decision-making during aircraft control is a novel approach to human–machine cooperation.
Using ensemble Kalman filter to determine parameters for computational crowd dynamics simulations
Authors: Togashi Fumiya , Misaka Takashi , Löhner Rainald , Obayashi Shigeru
Published: October 2018

Purpose

It is of paramount importance to ensure safe and fast evacuation routes in cities in case of natural disasters, environmental accidents or acts of terrorism. The same applies to large-scale events such as concerts, sport events and religious pilgrimages as airports and to traffic hubs such as airports and train stations. The prediction of pedestrian is notoriously difficult because it varies depending on circumstances (age group, cultural characteristics, etc.). In this study, the Ensemble Kalman Filter (EnKF) data assimilation technique, which uses the updated observation data to improve the accuracy of the simulation, was applied to improve the accuracy of numerical simulations of pedestrian flow.

Design/methodology/approach

The EnKF, one of the data assimilation techniques, was applied to the in-house numerical simulation code for pedestrian flow. Two cases were studied in this study. One was the simplified one-directional experimental pedestrian flow. The other was the real pedestrian flow at the Kaaba in Mecca. First, numerical simulations were conducted using the empirical input parameter sets. Then, using the observation data, the EnKF estimated the appropriate input parameter sets. Finally, the numerical simulations using the estimated parameter sets were conducted.

Findings

The EnKF worked on the numerical simulations of pedestrian flow very effectively. In both cases: simplified experiment and real pedestrian flow, the EnKF estimated the proper input parameter sets which greatly improved the accuracy of the numerical simulation. The authors believe that the technique such as EnKF could also be used effectively in other fields of computational engineering where simulations and data have to be merged.

Practical implications

This technique can be used to improve both design and operational implementations of pedestrian and crowd dynamics predictions. It should be of high interest to command and control centers for large crowd events such as concerts, airports, train stations and pilgrimage centers.

Originality/value

To the authors’ knowledge, the data assimilation technique has not been applied to a numerical simulation of pedestrian flow, especially to the real pedestrian flow handling millions pedestrian such as the Mataf at the Kaaba. This study validated the capability and the usefulness of the data assimilation technique to numerical simulations for pedestrian flow.
A bibliometric analysis for global research trends on ectomycorrhizae over the past thirty years
Authors: Jiang Xu , Yanbin Liu
Published: October 2018

Purpose

Based on the significance of ectomycorrhizae (ECM) and increased publication activity on this subject, it was decided to carry out a bibliometric analysis of scientific outputs in this area. The purpose of this study is to reveal the research trends of scientific outputs on ECM for the past 30 years and provide a potential guide for future research.

Design/methodology/approach

A method of bibliometric analysis was performed, based on the online version of the Science Citation Index Expanded, Web of Science, from 1986 to 2017. The authors evaluated the publication types, languages, source countries, journals, the patterns of publication outputs, most-cited articles, most-productive authors, institutional distributions, subject categories, high-frequency keywords and keywords plus and high-frequency terms in the title and abstract of ectomycorrhizal research. Keywords, keywords plus and high-frequency terms in the title and abstract were analyzed via VOSviewer to illustrate the extent of co-occurrence. This study further describes the recent research priority or hotspots and reveals the research trends.

Findings

From 1986 to 2017, the publication output on ECM showed a rising trend; the number of articles has rapidly increased after 2003. Based on co-occurrence analysis for keywords, keywords plus and terms in the title and abstract, “ectomycorrhizal fungi” is the most popular keyword and keywords plus; “concentration” is the most high-frequency terms in the title and abstracts. Plant biology, mycology and ecology are the hotspots in the ectomycorrhizal research. Ectomycorrhizal taxonomy, the molecular mechanisms of ectomycorrhizal symbioses and the common mycorrhizal networks are the future direction.

Originality/value

A bibliometric analysis has been carried out to analyze the trends of ECM research with 30 years. This study provides a potential guide for future research related to ectomycorrhizae.
An adaptive space-time shock capturing method with high order wavelet bases for the system of shallow water equations
Authors: Minbashian Hadi , Adibi Hojatollah , Dehghan Mehdi
Published: October 2018

Purpose

This paper aims to propose an adaptive method for the numerical solution of the shallow water equations (SWEs). The authors provide an arbitrary high-order method using high-order spline wavelets. Furthermore, they use a non-linear shock capturing (SC) diffusion which removes the necessity of post-processing.

Design/methodology/approach

The authors use a space-time weak formulation of SWEs which exploits continuous Galerkin (cG) in space and discontinuous Galerkin (dG) in time allowing time stepping, also known as cGdG. Such formulations along with SC term have recently been proved to ensure the stability of fully discrete schemes without scarifying the accuracy. However, the resulting scheme is expensive in terms of number of degrees of freedom (DoFs). By using natural adaptivity of wavelet expansions, the authors devise an adaptive algorithm to reduce the number of DoFs.

Findings

The proposed algorithm uses DoFs in a dynamic way to capture the shocks in all time steps while keeping the representation of approximate solution sparse. The performance of the proposed scheme is shown through some numerical examples.

Originality/value

An incorporation of wavelets for adaptivity in space-time weak formulations applied for SWEs is proposed.
Factors affecting the voluntary disclosure: a study by using smart PLS-SEM approach
Authors: Rouf Md. Abdur , Akhtaruddin M.
Published: October 2018

Purpose

This paper aims to examine the factors affecting the voluntary disclosure in the annual reports of listed companies in Bangladesh.

Design/methodology/approach

The study is based on a sample of 96 listed non-financial companies in Dhaka Stock Exchanges over the period of 2013 to 2016. The study used partial least squares structural equation modeling tool to analyze data which provides evidence of reliability and validity. It also used an unweighted relative disclosure index for measuring voluntary disclosure.

Findings

The empirical results show that corporate governance (board leadership structure and ownership structures) and firms characteristics (total assets and total sales) are significantly positive correlated with the voluntary disclosure.

Originality/value

The finding of the study will be a bench mark or the board for policy makers and implementers in torching the avenues of improvement in raising the level of corporate voluntary disclosure in annual reports of listed companies in Bangladesh.
Employment discrimination laws: a country level analysis of voice and accountability
Authors: Cheng Hong , Flores Gabriela , Singh Satvir , Posthuma Richard
Published: October 2018

Purpose

This paper aims to examine whether the number of employment discrimination laws in a country influences voice and accountability.

Design/methodology/approach

The authors compared the number of employment discrimination laws in different countries to perceptions of voice and accountability.

Findings

Results indicate that the number of discrimination laws enacted in a country has a positive impact on the voice and accountability perceptions of citizens. Further, this relationship is found to be moderated by two contextual factors: cultural assertiveness and the percentage of females in the population. Specifically, the positive impact of the number of discrimination laws on voice and accountability perceptions was found to be stronger in highly assertive cultures and in countries with a lower percentage of females in the population.

Originality/value

This is the first study to show a relationship between the number of employment discrimination laws in a country and perceptions of voice and accountability.
Cross-classified multilevel determinants of firm’s sales growth in Latin America
Authors: Fávero Luiz Paulo Lopes , Serra Ricardo Goulart , dos Santos Marco Aurélio , Brunaldi Eduardo
Published: October 2018

Purpose

The purpose of this paper is to analyze the influence of firm-, industry- and country-level determinants on real annual sales growth in the context of a cross-classified multilevel perspective.

Design/methodology/approach

The authors studied 11,381 firms from 17 industries in six Latin American countries based on the data collected up to 2015. Since the data are nested in two levels (level 1: firms; level 2: cross-classification of industries and countries), the authors use a cross-classified multilevel model. The significant variability in all levels of analysis confirms the option for the multilevel model.

Findings

Differences in industries account for the largest proportion of variance (77.2 percent). This finding indicates that industry-level characteristics should be explored in the sales growth literature (it seems to the authors that they were neglected). This finding also calls attention to the roles of policy-makers in facilitating firm growth. The final model indicates that the considered variables explain approximately 55 percent of the differences in real annual sales growth in the same industry and country after having accounted for the impacts of the differences in firms. After accounting for the impacts of the differences in firms’ and countries’ characteristics, 43 percent of the variation in average real annual sales growth is due to differences in industries. The obtained results indicate that while firms from countries with higher GDP growth and more effective corporate boards present higher real annual sales growth, firms that operate in commodity producer industries have worse performance in this indicator. With respect to firm’s characteristics, larger firms (contradicting Gibrat’s law) and exporters grew less. Some results could be explained by the decrease in commodities’ prices and global purchases between 2012 and 2015.

Originality/value

The paper fills some gaps in the firm growth literature by testing Gibrat’s law in non-developed countries (not yet done, to the best of the authors’ knowledge) and exploring variables other than size in the explanation of firm growth (rarely used, to the best of the authors’ knowledge). Moreover, the adopted model correctly estimated the origin of the variability in firm growth in its natural cross-classified distinct levels.
Oil prices, armed conflict and government revenue in Nigeria
Authors: Afangideh Udoma Johnson , Ujunwa Augustine , Ukemenam Angela Ifeanyi
Published: October 2018

Purpose

Persistent wave of armed conflicts – militancy and terrorism – and the mono-cultural structure of the Nigerian economy, as well as extensive reliance on revenue from crude oil, highlights how external vulnerabilities, weakening internal structure and insecurity could significantly exacerbate public revenue loss. Understanding the nature, trend and impact of these factors on government revenue is one of the questions that still remain unsolved. The purpose of this paper is to examine the impact of global oil prices, militancy and terrorism on government revenue in Nigeria.

Design/methodology/approach

The study focusses on the state-failure and frustration-aggression hypotheses to explain the nature and trend of armed conflicts in Nigeria. The autoregressive distributed lag (ARDL) model is used to examine the effect of global oil prices, militancy and terrorism on government revenue.

Findings

The study reveals that crude oil price, terrorism and militancy have significant negative effect on government revenue in short- and long-run Nigeria. Evidence from the study therefore supports the theory that macroeconomic fluctuation is largely determined by endogenous and exogenous factors in Nigeria.

Research limitations/implications

In view of this review, future studies should empirically analyse the interactive impact of militancy, terrorism and global oil prices on government expenditure or a combination of government revenue and expenditure.

Originality/value

The study provides evidence on the role of internal and external factors on macroeconomic fluctuation, and recommended appropriate suite of policies that could mitigate external and internal vulnerabilities, especially during upsurge in armed conflicts.
Exchange rate volatility in West African countries: is there a shred of Spillover?
Authors: Emenike Kalu Onwukwe
Published: October 2018

Purpose

The purpose of this paper is to evaluate selected West African currencies/US dollar exchange rates for the evidence of volatility spillover. Specifically, the paper examines West African CFA franc, Gambian dalasi and Nigerian naira exchange rates in relation to the USD, for any evidence of shock and volatility spillover.

Design/methodology/approach

The author employs multivariate GARCH (1,1)–BEKK model which enables the evaluation of the interaction within the volatility of two or more series because of its capability to detect volatility spillover among time series observations, as well as the persistence of volatility within each series.

Findings

The major findings of this study are as follows: there is evidence of volatility clustering in West African CFA franc, Gambian dalasi and Nigerian naira exchange rates in relation to the USD. There is evidence of bi-directional shock and volatility spillover between the Nigerian naira and West African CFA franc/USD exchange rates, and uni-directional shock spillover from the Gambian dalasi to the West African CFA franc/USD exchange rates. There is, however, no evidence of exchange rate shock and volatility spillover between Nigerian naira and Gambian dalasi.

Originality/value

Although considerable literature exists on the volatility of exchange rate in West Africa and comparative analysis of exchange rates volatility in few countries of West Africa, there is absence of empirical studies on exchange rate volatility spillover among countries in the region. Since containing exchange rate volatility is one of the major objectives of monetary policy, understanding the nature and direction of exchange rate volatility spillover would propel formulation exchange rate policies that would minimise exchange rate uncertainty and entrench sustainable development. In addition, the nature of exchange rate volatility spillover between West African countries would provide basis for international traders and foreign portfolio investors to develop effective strategies for hedging against exchange rate shocks that are propagated across countries by designing appropriate risk management techniques.
Performance of business group affiliated firms in emerging markets
Authors: Purkayastha Anish
Published: October 2018

Purpose

The purpose of this paper is to explore the existing mechanism through which business group affiliated firms in emerging markets (EMs) continue to generate superior performance.

Design/methodology/approach

The authors build our argument on the basis of how business group affiliation in EM facilitates internationalization and investment into innovation in affiliated firms compared to un-affiliated firm, resulting in higher firm performance. The authors use advance statistical modeling – causal mediation analysis to separate direct effect and indirect effect of business group affiliation in EM on performance through internationalization and investment into innovation of business group affiliated firms as mediating variables.

Findings

Based on 122,479 observations (firm year) from 17,235 Indian business group affiliated and un-affiliated firms, the findings help to identify that internationalization and investment into innovation of business group affiliated firms do have a mediating role in affiliation–performance relationship for EM business groups.

Originality/value

This study unravels the existing causal chain between business group affiliation in EMs and subsequent performance of affiliated firms. The authors complement institutional argument for superior performance of business group affiliation and focus on the performance implication of mediating strategic decisions in affiliated firms.
The effect of managerial ability on tax avoidance by classical and Bayesian econometrics in multilevel models
Authors: Akbari Farzana , Salehi Mahdi , Bagherpour Vlashani Mohammad Ali
Published: October 2018

Purpose

The purpose of this paper is to investigate the effect of managerial ability on tax avoidance in Tehran Stock Exchange (TSE) and OTC by classifying the income smoother and non-income smoother companies based on the theoretical approaches.

Design/methodology/approach

To measure the managerial ability the data envelopment analysis is applied based on the accounting data, company and industry characteristics. In this research, hypotheses are tested for the first time by three statistical methods, namely classical regression models, mixed effect multilevel models, and Bayesian multilevel models, which have never been addressed in Persian accounting research studies. The hypotheses are estimated during a 12-year period from 2004 to 2015 in TSE and OTC. In this research, according to Lucas’s critique, structural change test is used in order to control macroeconomic and political variables affecting the results of the study.

Findings

The results of hypothesis testing by employing three statistical methods suggest that only one hypothesis of this investigation is significant, which shows the significant association of type of market’s impact (exchange of OTC) on the relationship between managerial ability and tax avoidance.

Originality/value

Each company’s performance is affected by various factors. The study intends to mention that the performance of listed companies in the stock market depends heavily on its financial reports. And investors with perceived perception by the reports, can indirectly squeeze their stock indexes with their sudden sale of stocks, and question the company’s performance with losses to the company.
Strategic use of digital promotion strategies among female emigrant entrepreneurs in UAE
Authors: Jose Saju
Published: October 2018

Purpose

The purpose of this paper is to examine the strategic use of social media and chat applications of women entrepreneurs to promote their businesses.

Design/methodology/approach

Because of the nature of the study and dearth of sufficient data in the Middle Eastern society on the women entrepreneurship, this study employed a qualitative research methodology. The research comprised of 20 in-depth interviews with immigrant women entrepreneurs in the United Arab Emirates. They were identified through personal contacts and referrals.

Findings

All the expatriate women interviewed are using social media and chat applications to promote their business. Facebook is used for brand creation and WhatsApp is used as a direct marketing tool to evoke purchase response. Though traditional promotional tools are far from redundant, their role is more supplementary. The increasing trend is a combination of traditional tools and digital tools. Digital tools seem to have an upper hand in their business promotions.

Research limitations/implications

This study is limited to SME sector in one industry and in one country. The qualitative nature of this study could affect the generalizability of the results. A more extensive study is needed and future research should be more diverse including widening the selection of respondents, industries and countries.

Originality/value

This study is a novel attempt to gauge an in-depth understanding of modern communication tools. It looks specifically at the integrative strategies pursued by the immigrant women entrepreneurs using Facebook and WhatsApp.
The importance of spectrum loading in 2% milled MoS2 powder greases using four ball wear test
Authors: Nehme Gabi N.
Published: October 2018

Purpose

Loading condition and minimizing friction and wear using molybdenum disulfide grease in aircraft engine bearings are the focus of this research. The relationship between the milled and unmilled MoS2 (molybdenum disulfide) greases to its tribological properties, such as coefficient of friction, wear and chemical-mechanical properties of tribofilms, is examined for constant extreme pressure loading and spectrum or actual loading.

Design/methodology/approach

In this study, the design of experiments (DOE) approach was used to analyze the different loadings and speeds at a specific duration of 36,000 revolutions to examine the lithium base grease wear behavior with milled and unmilled MoS2 powder. Load is treated as variable that simulates actual conditions under 1,200 and 600 rpm rotational speeds using the four-ball test with chromium steel ball bearing aircraft grade E52100.

Findings

The results indicated that ball-milled MoS2 grease tests showed reduction in wear and friction under all conditions, especially spectrum or actual loading. Unmilled MoS2 powder exhibited worse wear outcomes than the milled one. The SEM and AES analyses indicated that a tribofilm is formed on the wear surface of the milled powder grease, especially at variable loading and initially at lower loads in the ramp-up tests that significantly enhanced the contact characteristics and prevented abrasion at higher loads.

Originality/value

This research indicated that the wear resistance in actual loading might be due to frictional heating generated during the ramping-up conditions where it provided a protective film that enhanced the steady-state friction for the duration of the test. Several researchers used ASTM standards to work on constant loading conditions. This is the first time that reduced milled MoS2 powder showed significant improvement in grease performance.
The ethics of outsourcing: when companies fail at responsibility
Authors: Ndubisi Nelson Oly , Nygaard Arne
Published: October 2018

Purpose

The purpose of this paper is to demonstrate that costs reduction is no longer a complete indication of performance and should not be attained at the expense of the firm’s sustainable social responsibility and environmental aspects. The question of whether outsourcing is a “blessing” or a “lesson” remains unresolved in the minds of practitioners and researchers alike. The literature is replete with the up- and down-sides of outsourcing, all going in different directions, making it very cumbersome particularly for practitioners to articulate when and what to outsource (if at all) and how to contain or mitigate outsourcing downsides.

Design/methodology/approach

Outsourcing as a two-edged sword can be value creating strategy or a firm’s soft spot. This paper focusses on the latter through a review of sourcing in two leading multinational companies: Benetton, in the fast fashion industry, and Nestlé, in the food industry.

Findings

Benetton experienced the biggest catastrophe in the garment industry, the Rana Plaza collapse. Nestlé went through the horse meat scandal, perhaps one of the most complex food crime cases in history. Both cases illustrated the strategic vulnerability that arises from the international outsourcing of production.

Research limitations/implications

Clearly, production costs are no longer a complete indication of performance as the two cases unveil. Management control systems should be especially vigilant when outsourcing transfers social and environmental responsibility from one contract to another in a global business context. Monitoring costs cannot be outsourced when it comes to sustainable social responsibility and environmental aspects.

Practical implications

Firms can leverage relationships with stakeholder groups, activists and NGOs to help them to monitor their international operations. Institution-based trust to protect brands, increased integration and control are necessary mechanisms.

Originality/value

Indeed, global outsourcing in any industry should transfer not only industrial operations but also credible and responsible social and environmental benchmarks.
Strategy war games: how business can outperform the competition
Authors: West Jason , Chu Maiko , Crooks Lincoln , Bradley-Ho Matthew
Published: October 2018

Purpose

Business wargames represent an alternative approach to challenge organisations to uncover internal capabilities through competitive actions designed to counteract external threats and address strategic mismatches. Internal capabilities uncovered as a result of actions taken during a competitive wargame aims to replicate market conditions found in competitive industries. These outcomes are difficult to achieve using many popular strategy design methods. The purpose of this study is to examine the use of war game-style activities in formulating corporate strategy that incorporate the natural behaviors of the leadership team in creating strategic plans.

Design/methodology/approach

Using a case study from the banc assurance industry, the authors review a wargame process composed of two competing teams; the banc assurance organisation and an unincorporated joint venture between a banking institution and an insurance company. The goal of each entity was to develop strategy to improve both customer satisfaction and market share at the expense of each other given a finite set of resources. Success was judged using a simple set of metrics defined by both a consumer team and an independent umpire.

Findings

Consumers of financial services are price sensitive and highly brand loyal. Unwillingness to switch brands to a prevailing competitor or other emerging (Fintech) institution persists to a threshold of a price and/or value differential of 15 to 20 per cent. The results highlight potential deficiencies in the proposed banc assurance strategy through the observation of customer behaviours and inefficient resource use.

Originality/value

The wargame approach conducted in a realistic landscape revealed internal capabilities not otherwise evident. The impact of authentic human behaviours in setting business strategy was captured which is very difficult to replicate using more formal scenario analysis and planning.
Acquisition integration flexibility: toward a conceptual framework
Authors: Schriber Svante , King David R. , Bauer Florian
Published: October 2018

Purpose

The purpose of this paper is to develop the role of integration flexibility as a mediator of acquisition performance and demonstrate how this capability varies across firms.

Design/methodology/approach

The study develops a conceptual framework of anticipated relationships by building on existing but so far unintegrated acquisition research.

Findings

The study suggests integration flexibility provides an explanation for variance in acquisition performance. The study identifies drivers behind acquisition integration flexibility in acquirer characteristics, deal characteristics and integration management. The authors further specify the positive and negative impact of several key factors commonly discussed in acquisition research.

Research limitations/implications

Integration flexibility stands out as a novel explanation for acquisition performance. Still, the benefits from flexibility are not universal and developed logic suggests it represents a dynamic capability for acquirers. Our framework helps predict which acquirers and deals are more likely demonstrating this capability, thus contributing to predict acquisition performance.

Practical implications

Acquisitions often take place in dynamic environments and reportedly often fail. Predicting and developing acquisition integration flexibility stands out as an important task for acquiring management.

Social implications

Annual global acquisition values are on par with the GDP of large industrial nations (e.g. Germany) and failures for reasons of lacking acquisition integration flexibility contributes to value destruction harming not only firms, but society at large. Improved integration flexibility likely mediates this risk.

Originality/value

Making an acquisition to adapt to environmental change implicitly assumes greater integration that can limit flexibility. While our argument builds on key concepts from acquisition research these so far have remained unconnected in relation to acquisition integration flexibility. The authors develop factors influencing this important capability and show how it mediates acquisition performance. This links acquisition antecedents with integration or phases typically treated separately.
Development of anti-corrosion coatings using the disposable waste material
Authors: Mohamad Saidi Norshahirah , Shafaamri Ammar Shafaamri , Wonnie Ma Iling Aema , Kasi Ramesh , Balakrishnan Vengadaesvaran , Subramaniam Ramesh
Published: October 2018

Purpose

The purpose of this study is to develop anti-corrosion coating systems using disposable waste materials. The dissolved polyethylene terephthalate (PET) has been blended with epoxy resin and stoichiometrically cured with a polyamide resin.

Design/methodology/approach

Glycolysis process was found to be the most optimum candidate to dissolve PET. The developed coating systems were characterized by Fourier transform infrared spectroscopy for confirmation of the molecular bonding structures. The mechanical properties were characterized by performing pull-off test and cross hatch test for mechanical properties on the coated panel. Also, the glossiness test was used by reflecting light on the coated surface. The corrosion protection performance of the coated mild steel panels was examined using electrochemical impedance spectroscopy. Furthermore, the wettability of the developed coating systems was evaluated by using water contact angle technique.

Findings

It was observed that the coating system which contains 10 per cent of dissolved PET (S2) showed the highest adhesion and corrosion protection properties.

Originality/value

Recyclable PET bottles have outstanding chemical properties, adhesion properties, low cost, low permeability to gases and solvents making it suitable as a coating with superior barrier properties.