bluuebunny/crossref_metadata_2025 huggingface dataset:
A Stu2-mediated intrinsic tension-sensing pathway promotes chromosome biorientation in vivo
Authors: Miller Matthew P. , Evans Rena K. , Zelter Alex , Geyer Elisabeth A. , MacCoss Michael J. , Rice Luke M. , Davis Trisha N. , Asbury Charles L. , Biggins Sue
Published: October 2018

Accurate segregation of chromosomes to daughter cells is a critical aspect of cell division. It requires the kinetochores on duplicated chromosomes to biorient, attaching to microtubules from opposite poles of the cell. Bioriented attachments come under tension, while incorrect attachments lack tension and must be destabilized. A well-studied error correction pathway is mediated by the Aurora B kinase, which destabilizes low tension-bearing attachments. We recently discovered that in vitro, kinetochores display an additional intrinsic tension-sensing pathway that utilizes Stu2. This pathway’s contribution to error correction in cells, however, was unknown. Here, we identify a Stu2 mutant that abolishes its kinetochore function and show that it causes error correction defects in vivo. We also show that this intrinsic tension-sensing pathway functions in concert with the Aurora B-mediated pathway. Together, our work indicates that cells employ at least two pathways to ensure biorientation and the accuracy of chromosome segregation.
Recent invasion of P transposable element intoDrosophila yakuba
Authors: Serrato-Capuchina Antonio , Zhang Stephania , Martin Wendy , Peede David , Earley Eric , Matute Daniel R.
Published: October 2018

Transposable elements (TEs) are self-replicating genetic units that are common across prokaryotes and eukaryotes. They have been implicated in the origin of new molecular functions and in some cases, new phenotypes. Yet, the processes that lead to their evolution and how they enter the genome of their hosts remain largely underexplored. The P-element is one of the most well-known TEs in Eukaryotes, due to its rapid expansion inDrosophila melanogasterin the 1960s and its faster invasion ofD. simulans, despite its fitness consequences in both species. Here, we describe a recent invasion of P-elements intoDrosophila yakuba. Overall, PEs were found inD. yakubawith no PEs detected across its sister species,D. teissieriandD. santomea. These findings are surprising due the lack of a genetic bridge betweenD. yakubaand otherDrosophilathat harbor PEs, implicating a horizontal gene transfer mechanism similar to the one that gave rise to the invasion of PEs inD. melanogasterandD. simulans. We also report that the presence of these PEs causes a mild hybrid dysgenesis phenomenon; namely they cause a reduction in female reproductive potential (lower number of ovaries and ovarioles), but only at 29°C and not at 23°C. Given the ability of PEs to cross species boundaries and the fact that bothD. santomeaandD. teissierihave the ability to produce fertile progeny withD. yakuba, theyakubaspecies complex provides an opportunity to study PE spread through vertical transmission.

ARTICLE SUMMARY

P-elements (PEs) are transposons found in NeotropicalDrosophilaspecies. PEs have previously invaded two AfricanDrosophilaspecies where they rapidly increased in population frequency and fixed. We found that PEs invaded the genome ofD. yakuba, an African species. In just 8 years, the frequency of the PEs increased from 0% to 18% but then decreased to 2%. This turnover shows that PE invasions can be transient. We found no evidence of full PEsin D. yakuba’ sister species,D. santomeaandD. teissieri. PEs in this species complex can reveal the interplay between transposable elements and hybridization in nature.
A reverse-transcription/RNase H based protocol for depletion of mosquito ribosomal RNA facilitates viral intrahost evolution analysis, transcriptomics and pathogen discovery
Authors: Fauver Joseph R. , Akter Shamima , Morales Aldo Ivan Ortega , Black William C. , Rodriguez Americo D. , Stenglein Mark D. , Ebel Gregory D. , Weger-Lucarelli James
Published: October 2018

Studies aimed at identifying novel viral sequences or assessing intrahost viral variation require sufficient sequencing coverage to assemble contigs and make accurate variant calling at low frequencies. Many samples come from host tissues where ribosomal RNA represents more than 90% of total RNA preparations, making unbiased sequencing of viral samples inefficient and highly expensive, as many reads will be wasted on cellular RNAs. In the presence of this amount of ribosomal RNA, it is difficult to achieve sufficient sequencing depth to perform analyses such as variant calling, haplotype prediction, virus population analyses, virus discovery or transcriptomic profiling. Many methods for depleting unwanted RNA or enriching RNA of interest have been devised, including poly-A selection, RNase H based specific depletion, duplex-specific nuclease treatment and hybrid capture selection, among others. Although these methods can be efficient, they either cannot be used for some viruses (i.e. non-polyadenylated viruses), have been optimized for use in a single species, or have the potential to introduce bias. In this study, we describe a novel approach that uses an RNaseH possessing reverse transcriptase coupled with selective probes for ribosomal RNA designed to work broadly for three medically relevant mosquito genera;Aedes,Anopheles,andCulex.We demonstrate significant depletion of rRNA using multiple assessment techniques from a variety of sample types, including whole mosquitoes and mosquito midgut contents from FTA cards. To demonstrate the utility of our approach, we describe novel insect-specific virus genomes from numerous species of field collected mosquitoes that underwent rRNA depletion, thereby facilitating their detection. The protocol is straightforward, relatively low-cost and requires only common laboratory reagents and the design of several small oligonucleotides specific to the species of interest. This approach can be adapted for use with other organisms with relative ease, thus potentially aiding virus population genetics analyses, virus discovery and transcriptomic profiling in both laboratory and field samples.
HypermorphicSERK1mutations function via aSOBIR1pathway to activate floral abscission signaling
Authors: Taylor Isaiah , Baer John , Calcutt Ryan , Walker John C.
Published: October 2018

In Arabidopsis, the abscission of floral organs is regulated by two related receptor-like protein kinases (RLKs), HAESA and HAESA-like 2 (HAE/HSL2). HAE/HSL2, in complex with members of the SERK family of coreceptor protein kinases, are activated by the binding of the proteolytically processed peptide ligand IDA. This leads to expression of genes encoding secreted cell wall remodeling and hydrolase enzymes.hae hsl2mutants fail to induce expression of these genes and retain floral organs indefinitely. In this paper we report identification of an allelic series ofhae hsl2suppressor mutations in theSERK1coreceptor protein kinase gene. Genetic and transcriptomic evidence indicates these alleles represent a novel class of gain of function mutations that activate signaling independent of HAE/HSL2. We show that the suppression effect surprisingly does not rely on protein kinase activity of SERK1, and that activation of signaling relies on the RLK geneSOBIR1. The effect of these mutations can be mimicked by loss of function ofBIR1,a known negative regulator ofSERK-SOBIR1signaling. These results suggestBIR1functions to negatively regulateSERK-SOBIR1signaling during abscission, and that the identifiedSERK1mutations likely interfere with this negative regulation.
Red squirrels mitigate costs of territory defence through social plasticity
Authors: Siracusa Erin R. , Wilson David R. , Studd Emily K. , Boutin Stan , Humphries Murray M. , Dantzer Ben , Lane Jeffrey E. , McAdam Andrew G.
Published: October 2018

For territorial species, the ability to be behaviourally plastic in response to changes in their social environment may be beneficial by allowing individuals to mitigate conflict with conspecifics and reduce the costs of territoriality. Here we investigated whether North American red squirrels (Tamiasciurus hudsonicus) were able to minimize costs of territory defence by adjusting behaviour in response to the familiarity of neighbouring conspecifics. Since red squirrels living in familiar neighbourhoods face reduced intrusion risk, we predicted that increasing familiarity among territorial neighbours would allow squirrels to spend less time on territorial defence and more time in the nest. Long-term behavioural data (1995-2004) collected from the same squirrels across several different social environments indicated that red squirrels reduced rates of territorial vocalizations and increased nest use in response to increasing familiarity with neighbours. In contrast, cross-sectional data (2015-2016), which provided observations from each individual in a single social environment, did not provide evidence of this plasticity. Post-hoc analyses revealed that evidence of social plasticity in this system was primarily due to within-individual changes in behaviour, which we were unable to estimate in the cross-sectional data. Our results demonstrate that red squirrels can reduce the costs of territoriality by appropriately adjusting behaviour in response to changes in their social environment. However, our results also suggest that estimating plasticity by comparing behaviour among individuals (i.e. cross-sectional analyses) may not always be reliable. Our ability to detect these effects may therefore depend on having data with multiple observations from the same individuals across different social environments.
Bright split red fluorescent proteins with enhanced complementation efficiency for the tagging of endogenous proteins and visualization of synapses
Authors: Feng Siyu , Varshney Aruna , Villa Doris Coto , Modavi Cyrus , Kohler John , Farah Fatima , Ali Nebat , Mueller Joachim Dieter , VanHoven Miri , Huang Bo
Published: October 2018

Self-associating split fluorescent proteins (FPs) have been widely used for labeling proteins, scaffolding protein assembly and detecting cell-cell contacts. Newly developed self-associating split FPs, however, have suffered from suboptimal fluorescence signal. Here, by investigating the complementation process, we have demonstrated two approaches to improve split FPs: assistance through SpyTag/SpyCatcher interaction and directed evolution. The latter has yielded two split sfCherry3 variants with substantially enhanced overall brightness, facilitating the tagging of endogenous proteins by gene editing. Based on sfCherry3, we have further developed a new red-colored trans-synaptic marker called Neuroligin-1 sfCherry3 Linker Across Synaptic Partners (NLG-1 CLASP) for multiplexed visualization of neuronal synapses in living animals, demonstrating its broad applications.
Probability cueing of singleton-distractor locations in visual search: priority-map‐ or dimension-based inhibition?
Authors: Zhang Bei , Allenmark Fredrik , Liesefeld Heinrich R. , Shi Zhuanghua , Müller Hermann J.
Published: October 2018

Observers can learn the likely locations of salient distractors in visual search, reducing their potential to capture attention (Ferrante et al., 2018; Sauter et al., 2018a; Wang & Theeuwes, 2018a). While there is agreement that this involves positional suppression of the likely distractor location(s), it is contentious at which stage of search guidance the suppression operates: the supra-dimensional priority map or feature-contrast signals within the distractor dimension. On the latter account, advocated by Sauter et al., target processing should be unaffected by distractor suppression when the target is defined in a different (non-suppressed) dimension to the target. At odds with this, Wang and Theeuwes found strong suppression not only of the (color) distractor, but also of the (shape) target when it appeared at the likely distractor location. Adopting their paradigm, the present study ruled out that increased cross-trial inhibition of the single frequent (frequently inhibited) as compared to any of the rare (rarely inhibited) distractor locations is responsible for this target-location effect. However, a reduced likelihood of the target appearing at the frequent vs. a rare distractor location contributes to this effect: removing this negative bias abolished the cost to target processing with increasing practice, indicative of a transition from priority-map‐ to dimension-based – and thus a flexible locus of – distractor suppression.

Public Significance Statement

Distraction by a salient visual stimulus outside the ‘focus’ of the task at hand occurs frequently. The present study examined whether and how ‘knowledge’ of the likely location(s) where the distractors occur helps the observer to mitigate distraction. The results confirmed that observers can learn to suppress distracting stimuli at likely locations. Further, they showed that, the suppression may occur at different levels in the hierarchically organized visual system where the priorities of which objects to be attended in the environment are determined.
Fast Hierarchical Bayesian Analysis of Population Structure
Authors: Tonkin-Hill Gerry , Lees John A. , Bentley Stephen D. , Frost Simon D.W. , Corander Jukka
Published: October 2018

We present fastbaps, a fast solution to the genetic clustering problem. Fastbaps rapidly identifies an approximate fit to a Dirichlet Process Mixture model (DPM) for clustering multilocus genotype data. Our efficient model-based clustering approach is able to cluster datasets 10-100 times larger than the existing model-based methods, which we demonstrate by analysing an alignment of over 110,000 sequences of HIV-1 pol genes. We also provide a method for rapidly partitioning an existing hierarchy in order to maximise the DPM model marginal likelihood, allowing us to split phylogenetic trees into clades and subclades using a population genomic model. Extensive tests on simulated data as well as a diverse set of real bacterial and viral datasets show that fastbaps provides comparable or improved solutions to previous model-based methods, while generally being significantly faster. The method is made freely available under an open source MIT licence as an easy to use R package athttps://github.com/gtonkinhill/fastbaps.
A Whole-Genome Association Approach for Large-scaled Inter-species Trait
Authors: Wu Qi , Fan Huizhong , Chen Lei , Hu Yibo , Wei Fuwen
Published: October 2018

Genome wide association studies (GWAS) have provided an avenue for the association between common genetic variants and complex traits. However, using SNP as a genetic marker, GWAS has been confined to detect genetic basis traits only for within species but not for the large-scale inter-species traits. Here, we propose a practical statistical approach that is using kmer frequencies as the genetic markers to associate genetic variants with large scale inter-species traits. We applied this new approach to the trait of chromosome number in 96 mammalian proteomes, and we prioritized 130 genes including TP53 and BAD, of which 6 were candidate genes. These genes were proved to be associated with cellular reaction of DNA double-strand breaks caused by chromosome fission/fusion. Our study provides a new effective genomic strategy to perform association studies for large-scaled inter-species traits, using the chromosome number as a case. We hope this approach could provide exploration for broadly widely traits.
In vitro model of inflammatory, hypoxia, and cancer stem cell signaling in pancreatic cancer using heterocellular 3-dimensional spheroids
Authors: Suresh Megha , Mattheolabakis George , Singh Amit , Amiji Mansoor
Published: October 2018

Introduction

As one of the most aggressive cancers worldwide, pancreatic cancer is associated with an extremely poor prognosis. The pancreatic tumor microenvironment consists of cancer cells and other tumor associated cells. Cross-talk between these different cell types through various signaling molecules results in the development of a more aggressive and malignant phenotype. Additionally, due to the highly dysregulated vasculature of tumors, the inner tumor core becomes hypoxic and eventually necrotic. Therefore, there is a need for the development of a physiologically relevant in vitro model that recapitulates these dynamic cell-cell interactions and the 3-dimensional (3D) structure of pancreatic tumors.

Methods

Four different 3D co-culture spheroid models using different combinations of Panc-1 tumor cells, J774.A1 macrophages, and NIH-3T3 fibroblast cell lines were reproducibly developed using the hanging drop technique in order to mimic the tumor microenvironment and to evaluate the differences in expression of various inflammatory, hypoxia, and cancer stem cell markers, including IL-8, TNF-α, TGF-β, HIF-1α HIF-2α, SCF, and LDH-A. Additionally, immunofluorescence studies were employed to investigate whether these spheroids tested positive for a cancer stem cell population.

Results

Pronounced differences in morphology as well as expression of signalling markers were observed using qPCR, indicative of strong influences of co-culturing different cell lines. These models also tested positive for cancer stem cell (CSCs) markers based on immunofluorescence and qPCR analysis.

Conclusion

Our results demonstrate the potential of 3D co-culture spheroid models to capture the inflammatory and hypoxic markers of pancreatic tumor microenvironment. We further demonstrate the presence of cancer cells with stem cell markers, similar to actual pancreatic cancer tumor. These spheroids present excellent in vitro system to study tumor-immune-stromal cell interactions as well as test deliverability of potential therapeutics in the tumor microenvironment with accurate physical and physiological barriers.
Effects of the Salinity under Soilless Culture Systems on Gamma Linolenic Acid Levels in Borage Seed Oil
Authors: Urrestarazu Miguel , Manuel Gallegos-Cedillo Victor , Ferrón-Carrillo Francisca , Luis Guil-Guerrero José , Lao Teresa , Eugenio Álvaro Juan
Published: October 2018

Borage is a well-known plant of great importance in human nutrition and health. Expanding knowledge of particular plants that have anti-cancer products is a global concern. There is substantial information regarding the benefits, presence and extraction of gamma linolenic acid (GLA) in different plants around the world, especially in borage seeds. However, there is little information concerning the effects of the salinity of the nutrient solution on the growth and presence of GLA in borage seeds. The objective of this work was to determine the optimal salinity of the nutrient solution for obtaining GLA in soilless cultivation systems. Borage plants were grown in coconut fibre and provided three treatments of nutrient solution of 2.20, 3.35 and 4.50 dS m−1, increasing solution salinity with the standard nutrient solution of concentrated macronutrients as a reference. Vegetative growth, seed production and GLA ratio were measured. The results of vegetative development and GLA production doubled and tripled with the increase in salinity of the nutrient solution, respectively.
Enumeration, Antagonism and Enzymatic Activities of Microorganisms Isolated from Railway Station Soil
Authors: Sharma Megha , Kaushik Prashant , Chaturvedi Pawan
Published: October 2018

Soil is the well-known hotspot for microbial diversity. Therefore, for our investigation, we isolated, characterized, and identified microorganisms from railway station soil. Sampling was done subsequently after every 15 days interval, and from two different soil depths i.e. 0-15 cm and below during March to May of 2013. Further, soil isolates were examined for their antagonistic activity, against four soil born plant pathogens namely,Rhizoctonia solani, Aspergillus niger, Fusarium f sp pisi, andSclerotinia sclerotiorum. Subsequently, isolates were screened for the presence of amylases, proteases, lipases and cellulases. For each interval of soil sampling, a gradual reduction in the microbial count was noticed from month March to May. Mucor species was observed only in the rainy days. The most promising enzymes producers wereBacillus sp., Aspergillus and Penicillium sp. Overall, the fungal isolates were better producers of enzymes as compared to bacterial isolates.
Ruthenium(II)–carbonyl complexes containing two N-monodentate 1,8-naphthyridine ligands: active catalysis in transfer hydrogenation reactions
Authors: Guajardo Juana , Ibañez Andrés , Guerchais Veronique , Vega Andrés , Moya Sergio , Aguirre Pedro
Published: October 2018

The reaction of 2-aminonicotinaldehyde with 2- or 4-methoxyacetophenone in basic media leads to the new ligands 2-(4-methoxyphenyl)-1,8-naphthyridine and 2-(2-methoxyphenyl)-1,8-naphthyridine, respectively, in high yield. The reaction of these naphthyridine derivatives with [RuCl2(CO)2]
n
leads to the respective complexes cis-dicarbonyldichloridobis[2-(4-methoxyphenyl)-1,8-naphthyridine-κN
8]ruthenium(II) and cis-dicarbonyldichloridobis[2-(2-methoxyphenyl)-1,8-naphthyridine-κN
8]ruthenium(II), both [RuCl2(C15H12N2O)2(CO)2], in good yield. Both ruthenium(II) complexes display a slightly distorted octahedron with two cis carbonyl, two cis chloride and two cis naphthyridine ligands, the latter coordinated in a monodentate fashion through the N atom in the 8-position. Both complexes exhibit a moderate catalytic activity in the hydrogen-transfer reaction from propan-2-ol to acetophenone in the presence of a base, with 100% selectivity.
2-Amino-5-chlorobenzophenone
Authors: Javed Saleem , Faizi Md. Serajul Haque , Nazia Siddiqui , Iskenderov Turganbay
Published: October 2018

The asymmetric unit of the title compound (systematic name: 2-benzoyl-4-chloroaniline), C13H10ClNO, contains four independent molecules with similar dihedral angles between the benzene rings [ranging from 53.7 (2) to 59.8 (2)°]. In the crystal, the molecules are linked by N—H...O hydrogen bonds into a three-dimensional supramolecular architecture.
Positioning variation analysis and control for automated drilling in aircraft manufacturing
Authors: Mei Biao , Zhu Weidong , Ke Yinglin
Published: October 2018

Purpose

Aircraft assembly demands high position accuracy of drilled fastener holes. Automated drilling is a key technology to fulfill the requirement. The purpose of the paper is to conduct positioning variation analysis and control for an automated drilling to achieve a high positioning accuracy.

Design/methodology/approach

The nominal and varied connective models of automated drilling are constructed for positioning variation analysis regarding automated drilling. The principle of a strategy for reducing positioning variation in drilling, which shortens the positioning variation chain with the aid of an industrial camera-based vision system, is explored. Moreover, other strategies for positioning variation control are developed based on mathematical analysis to further reduce the position errors of the drilled fastener holes.

Findings

The propagation and accumulation of an automated drilling system’s positioning variation are explored. The principle of reducing positioning variation in an automated drilling using a monocular vision system is discussed from the view of variation chain.

Practical implications

The strategies for reducing positioning variation, rooted in the constructed positioning variation models, have been applied to a machine-tool based automated drilling system. The system is developed for a wing assembly of an aircraft in the Aviation Industry Corporation of China.

Originality/value

Propagation, accumulation and control of positioning variation in an automated drilling are comprehensively explored. Based on this, the positioning accuracy in an automated drilling is controlled below 0.13 mm, which can meet the requirement for the assembly of the aircraft.
Aircraft positioning using SPP method in GPS system
Authors: Krasuski Kamil
Published: October 2018

Purpose

The purpose of this paper is based on implementation of Global Navigation Satellite System (GNSS) technique in civil aviation for recovery of aircraft position using Single Point Positioning (SPP) method in kinematic mode.

Design/methodology/approach

The aircraft coordinates in ellipsoidal frame were obtained based on Global Positioning System (GPS) code observations for SPP method. The numerical computations were executed in post-processing mode in the Aircraft Positioning Software (APS) package. The mathematical scheme of equation observation of SPP method was solved using least square estimation in stochastic processing. In the experiment, airborne test using Cessna 172 aircraft on September 07, 2011 in the civil aerodrome in Mielec was realized. The aircraft position was recovery using observations data from Topcon HiperPro dual-frequency receiver with interval of 1 second.

Findings

In this paper, the average value of standard deviation of aircraft position is about 0.8 m for Latitude, 0.7 m for Longitude and 1.5 m for ellipsoidal height, respectively. In case of the Mean Radial Spherical Error (MRSE) parameter, the average value equals to 1.8 m. The standard deviation of receiver clock bias was presented in this paper and the average value amounts to 34.4 ns. In this paper, the safety protection levels of Horizontal Protection Level (HPL) and Vertical Protection Level (VPL) were also showed and described.

Research limitations/implications

In this paper, the analysis of aircraft positioning is focused on application the least square estimation in SPP method. The Kalman filtering operation can be also applied in SPP method for designation the position of the aircraft.

Practical implications

The SPP method can be applied in civil aviation for designation the position of the aircraft in Non-Precision Approach (NPA) GNSS procedure at the landing phase. The typical accuracy of aircraft position is better than 220 m for lateral navigation in NPA GNSS procedure. The limit of accuracy of aircraft position in vertical plane in NPA GNSS procedure is not available.

Social implications

This paper is destined for people who works in the area of aviation and air transport.

Originality/value

The work presents that SPP method as a universal technique for recovery of aircraft position in civil aviation, and this method can be also used in positioning of aircraft based on Global Navigation Satellite System (GLONASS) code observations.
Constant-gain EKF algorithm for satellite attitude determination systems
Authors: Hua Song , Huang Huiyin , Yin Fangfang , Wei Chunling
Published: October 2018

Purpose

This paper aims to propose a constant-gain Kalman Filter algorithm based on the projection method and constant dimension projection, which ensures that the dimension of the observation matrix obtained is maintained when there is a satellite with multiple sensors.

Design/methodology/approach

First, a time-invariant observation matrix is determined with the projection method, which does not require the Jacobi matrix to be calculated. Second, the constant-gain matrix replaces the EKF (extended Kalman filter) gain matrix, which requires online computation, considerably improving the stability and real-time properties of the algorithm.

Findings

The simulation results indicate that compared to the EKF algorithm, the constant-gain Kalman filter algorithm has a considerably lower computational burden and improved real-time properties and stability without a significant loss of accuracy. The algorithm based on the constant dimension projection has better real-time properties, simpler computations and greater fault tolerance than the conventional EKF algorithm when handling an attitude determination system with three or more star trackers.

Originality/value

In satellite attitude determination systems, the constant-gain Kalman Filter algorithm based on the projection method reduces the large computational burden and improve the real-time properties of the EKF algorithm.
Control of pendular motion on tethered satellites systems
Authors: Tirop Paul Kimutai , Jingrui Zhang
Published: October 2018

Purpose

This paper aims to present the control laws to be used in the control of pendular motion on tethered satellite systems in space during orbiting by using a nonlinear design technique.

Design/methodology/approach

This work presents both physical and mathematical models represented in a circular orbit. Euler equation of the rigid body is applied under reasonable assumption so as to form the equations of pendular motion. These equations are then used to develop the control laws using a nonlinear design technique. The control laws are required to drive the in-plane angles and out-of-plane angles of the pendular motion to the required trajectories. Simulations are then conducted to study the control results.

Findings

Simulation results show that the control laws in both plane angles of motions considered are able to move the pendular motion to the required trajectory. It was also eminent that a lot of effort is required in the case of the reference trajectory that corresponds to the constant inside-plane. To control the pendular motion of the plane, one requires an extended period of time and it should be controlled within a reasonable range. In the outside-of-plane pendular motion, minimal or no effort is required for the control. The reason is that the trajectory is natural planar.

Practical implications

This research is expected to provide a dynamic control strategy for all tethered satellite space systems.

Originality/value

The research proposes a combined dynamic method for the purpose of improving the control of all types of tether satellites.
Antecedents of switching intention in the mobile telecommunications industry
Authors: Quoquab Farzana , Mohammad Jihad , Yasin Norjaya Md , Abdullah Nor Liza
Published: October 2018

Purpose

This study sheds some light on factors that affect customer switching intention in the Malaysian mobile phone service industry. More particularly, the purpose of this paper is to examine the effect of service quality (SQ), customer satisfaction, switching cost and consumer innovativeness (CI) on service switching intention (SWI); the mediating role of customer satisfaction; and the moderating role of service switching cost on the relationship between CI and SWI.

Design/methodology/approach

Data were collected using a self-administered questionnaire survey that yielded 535 responses. Using structural equation modelling approach, the partial least square software, version 3 was utilised to test the study hypotheses.

Findings

Results reveal that customer satisfaction, service switching cost and CI directly affect SWI. However, no significant relationship was found between SQ and SWI. Again, data supported the mediating effect of customer satisfaction as well as the moderating effect of service switching cost.

Research limitations/implications

It is expected that the findings from this study will enable policymakers, managers and marketers to formulate better strategies and effectively implement loyalty programs, preventing their customers from switching.

Originality/value

This study contributes to the existing literature by testing switching costs as the quasi moderator. Moreover, this is a pioneer study to consider CI as the antecedent of SWI.
Dynamic study of corporate governance structure and firm performance in China
Authors: Shao Lin
Published: October 2018

Purpose

The paper aims to provide a comprehensive investigation of the relationship between corporate governance (CG) structure and firm performance in Chinese listed firms from 2001 to 2015. The authors’ motivation derives from the fact that the CG system in China is different from those in the US, the UK, Germany, Japan and other countries.

Design/methodology/approach

A large unbalanced sample, covering more than 22,700 observations in Chinese listed firms, was used to explore, by means of a system-generalized method-of-moments (GMM) estimator, the relationship between CG structure and firm performance to remove potential sources of endogeneity.

Findings

Results show that Chinese CG structure is endogenously determined by the CG mechanisms investigated: there is no relationship between board size (including independent directors) and firm performance; CEO duality has a significantly negative effect on firm performance; concentration of ownership has a significantly positive influence on firm performance; managerial ownership is negatively correlated with firm performance; state ownership has a significantly positive effect on firm performance; and a supervisory board is positively correlated with firm performance.

Practical implications

The findings provide policymakers and firm managers with useful empirical guidance concerning CG in China.

Originality/value

Few integrative studies have examined the impact of CG structure on firm performance in China. This study adds new empirical evidence that the relation between CG structure and performance in China is endogenous and dynamic when controlling for unobserved heterogeneity, simultaneity, and dynamic endogeneity.
Three-dimensional combined radiation-magnetoconvection of low electrically conductive dielectric oxide melt
Authors: Al-Rashed Abdullah A.A.A. , Kolsi Lioua , Tashkandi Mohammed A. , Hasani Malekshah Emad , Chamkha Ali J. , Borjini Mohamad Naceur
Published: October 2018

Purpose

The purpose of this paper is to investigate the coupled effect of magnetic field and radiation on convective heat transfer of low electrically conductive dielectric oxide melt.

Design/methodology/approach

The 3D Navier–Stokes equations are formulated using the vector potential-vorticity formulation and solved using the finite volume method (FVM). The radiative heat transfer equation is discretized using the FTnFVM method. A code was written using FORTRAN language.

Findings

The obtained numerical results are focused on the effect of the different parameters on the heat transfer and the flow structure with a special interest on the 3D transvers flow. It is found that the flow is developing in inner spirals and the magnetic field intensifies this 3D character. The radiation acts mainly at the core of the enclosure and causes the apparition of the merging phenomenon near the front and back walls.

Originality/value

The effect of magnetic field on convective heat transfer of highly electrically conductive fluids has been intensively studied. Reciprocally, the case of a fluid with low electrical conductivity is not so much investigated, especially when it is coupled with the effect of radiation. These two effects are studied in this paper for the case of a low-conductive LiNbO3 oxide melt.
On the application of passive flow control for cavitation suppression in torque converter stator
Authors: Liu Cheng , Wei Wei , Yan Qingdong , Weaver Brian K. , Wood Houston G.
Published: October 2018

Purpose

The purpose of this paper is to study the transient cavitation process in torque converters with a particular focus on cavitation suppression with a passive flow control technique.

Design/methodology/approach

The transient fluid field in a torque converter was simulated by RANS-based computational fluid dynamics (CFD) in a full three-dimensional (3D) model. A homogeneous Rayleigh–Plesset cavitation model was used to simulate the transient cavitation process and the results were validated with test data. Various secondary flow passages (SFP) were applied to the stator blade. The cavitation behavior and hydrodynamic performance were simulated and compared to investigate the effect of SFP geometries on cavitation suppression.

Findings

Presented results show that cavitation in the torque converter is highly unstable at stall operating condition because of the combination of a high incidence angle and high flow velocity. The addition of an SFP to the stator blade produces a disruption of the re-entrant jet and reduces the overall degree of cavitation, consequently inhibiting the unstable cavitation and reducing performance degradation.

Originality/value

This paper provides unique insights into the complicated transient cavitation flow patterns found in torque converters and introduces effective passive flow control techniques useful to researchers and engineers in the areas of fluid dynamics and turbomachinery.
Ownership type, bank models, and bank performance: the case of the Yemeni banking sector
Authors: Shawtari Fekri Ali Mohammed
Published: October 2018

Purpose

The purpose of this paper is to examine bank performance using the different performance measures, namely, return on assets, return on equity and bank margins (MAR).

Design/methodology/approach

Unbalanced panel data were constructed to test the related hypotheses and provide evidence on the relationship between ownership types, banking models and performance indicators adopting the random effects techniques.

Findings

The findings of the paper substantiate that the banking models are significant performance indicators. However, the results are contingent on the GDP growth of the country. Moreover, the evidence indicates that the impact of ownership types is inconclusive in all measures of performance. However, the GDP is significant when it interacts with the types of ownership, particularly for foreign and government banks, although the evidence is mixed and unfavourable for government banks.

Practical implications

The results of the study provide insights for bankers and policymakers to enhancement Yemen’s banking sector.

Originality/value

This study is considered as the first attempt in examining the role of banking model and ownership type and their link to banking model.
Value and barriers in the creation of intellectual property in advanced manufacturing: a country comparison
Authors: Charterina Jon , Araujo Andrés
Published: October 2018

Purpose

The purpose of this paper is to determine to what extent small sized and periphery-located firms compensate the comparative disadvantages of big centrally located firms, through patent ownership agreements with other agents, notably research institutes.

Design/methodology/approach

The authors develop an empirical study of patents from two completely different economic areas, a central and a peripheral one, represented by Germany and Spain, respectively, in the domain of the Key Enabling Technology (KET) of advanced manufacturing technologies in robotics and automation. Comparing the population of 211 Spanish patents granted with a random sample of 500 German patents, from the files of the US Patent and Trademark Office, the authors obtain and test a series of logistic regression functions taking the predicted possibilities to develop patents with more citations, as a proxy for their value.

Findings

Whereas big companies from central locations do not obtain more heavily cited patents from sharing their R&D activity with other firms or research institutes, smaller manufacturing firms in peripheral areas, namely, Spain, may find this advantageous. Additionally, patents containing fewer cited articles and citations of previous patents, tend to be cited more frequently. Finally, this same outcome is also observed with patents showing shorter time between the application and grant.

Originality/value

To the best of the authors’ knowledge, this is the first study on patent value which examines the KET of advanced manufacturing technologies in robotics and automation, comparing a central to a peripheral geographic environment, and determining the number, diversity and size of patent assignees. The results prove relevant in general for manufacturing businesses, especially in the Machine-Tool and machinery producing industry. Overwhelmingly, these firms tend to be SMEs basing their marketing activity entirely on a Business-to-Business (B2B) focus, and facing serious obstacles for R&D activity.
A systematic review of the concept of entrepreneurial alertness
Authors: Sharma Lalit
Published: October 2018

Purpose

Entrepreneurial alertness is a key factor in business opportunity identification. Scholars have determined that successful entrepreneurs have high levels of entrepreneurial alertness, but only a limited number of studies are available on the concept. One of the major reasons identified is the fragmented constituents and less knowledge of the components determining the level of alertness. The present study aims to integrate the varied research on entrepreneurial alertness, identify its core components and develop the understanding of the concept of entrepreneurial alertness.

Design/methodology/approach

The study is based on a systematic review of secondary research. The first stage involved identifying relevant publications and applying practical screening. In the second stage, the resources were screened for the inclusion criteria, and in the final stage, the articles meeting the inclusion criteria were read in detail for the final analysis.

Findings

The review resulted in identification of the following core components of the alertness construct – sensing and searching information, cognitive ability, personality factors (like creativity and self-efficacy), environment, social networks, knowledge and experience. The review also highlighted that cognitive ability plays a central role in alertness.

Originality/value

Based on the review of literature, the study proposes a model of the alertness construct, which attempts to draw a relationship between the identified components. The review also uncovers several unexplored areas, which still need to be addressed in the area of entrepreneurial alertness.
Loss aversion, overconfidence of investors and their impact on market performance evidence from the US stock markets
Authors: Bouteska Ahmed , Regaieg Boutheina
Published: October 2018

Purpose

The current study aims to investigate the impacts of two behavioral biases, namely, loss aversion and overconfidence on the performance of US companies. First, the impact of loss aversion on the economic performance of companies was assessed. Second, the impact of overconfidence on market performance was discussed.

Design/methodology/approach

This study used around 6,777 quarterly observations on the population of US-insured industrial and services companies over the 2006-2016 period. Ordinary least squares (OLS) regression in two panel data models were used to test the hypotheses formulated for the study.

Findings

It was documented that the loss-aversion bias negatively affects the economic performance of companies and this is achieved for both sectors. In contrast, the findings suggest that overconfidence positively affects market performance of industrial firms but negatively affects market performance in service firms. Further robust evidence was found that overconfidence bias seems to be dominant, and hence, investors may tend to be more overconfident rather than more loss-averse.

Originality/value

This research can be extended by focusing on the following question: What is the impact of the contradictory (positive and negative) effects of an investor's loss aversion and overconfidence on the US company performance in case of realization of a stock market crisis or stock market crash?
Banking crises and business cycle: evidence for Italy(1861-2016)
Authors: Bartoletto Silvana , Chiarini Bruno , Marzano Elisabetta , Piselli Paolo
Published: October 2018

Purpose

This paper aims to focus on the banking crises recorded in Italy in the period 1861-2016 and to propose a novel classification based upon the timing of the crisis with respect to the business cycle.

Design/methodology/approach

A simple and objective rule to distinguish between slowdown and inner-banking crises is introduced. The real impact of banking crises is evaluated by integrating the narrative approach with an empirical vector autoregression analysis.

Findings

First, banking crises are not always associated to economic downturns. Especially in Italy, (but this analysis can be easily extended to other countries), they have often limited their negative effects within the financial system (“inner” crises). Second, the simultaneity of macroeconomic effects (credit contraction and GDP recession) leave the causal link undetermined. Third, the empirical and narrative analyses performed testify that boom–bust mechanisms are an exception in the panorama of (Italian) banking crises; although when the economy experiences such episodes, the economic and social consequences are not only severe but also enduring.

Research limitations/implications

To classify historically recognized banking crisis episodes, the authors look at credit and GDP dynamics (and their ratio) around crisis years. Relying on a single definition of crisis is avoided. The classification provides an empirical rule to determine in what way banking crises differ. The classification is mostly based on the synchronization with the business cycle and, using the documented evolution of macroeconomic aggregates, it permits to highlight the fact that a variety of interactions occur between financial and real aggregates during and around banking crises.

Originality/value

As to the concept of systemic banking crisis, a qualitative judgment is often adopted to select relevant episodes, thus confirming the absence of a quantitative rule in classification criteria (Chaudron and de Haan, 2014). This paper proposes a simple and objective rule to distinguish between slowdown and inner-banking crises; the former occur close to a GDP contraction, whereas the latter appear to spread their effects with no substantial evidence of output loss.
The effect of corruption on FDI and its modes of entry
Authors: Luu Hiep Ngoc , Nguyen Ngoc Minh , Ho Hai Hong , Nam Vu Hoang
Published: October 2018

Purpose

The purpose of this paper is to empirically investigate the impact of corruption on foreign direct investment (FDI) and its two major modes of entry: greenfield investment (greenfield) and cross-border mergers and acquisitions (M&As).

Design/methodology/approach

Data are collected from 131 countries. Modern econometric techniques, including the generalized method of moments (GMM) estimator, two-stage least square estimator and two-step system GMM estimator, are used to evaluate the impact of corruption on FDI activities.

Findings

The empirical results illustrate that corruption is a deterioration factor that significantly hinders FDI inflows. However, this finding turns out to be contradictory when the two major components of FDI – greenfield investment and cross-border M&As – are separately examined. Specifically, while corruption consistently discourages cross-border M&As over time, it appears to exert positive effect on greenfield investments.

Originality/value

This is among the first to empirically examine the impact of corruption on FDI and its modes of entry in a number of countries spanning different time windows. In this sense, this paper also captures the changing nature of societies and economic conditions overtime and, therefore, enable academic researchers, policy-makers and business practitioners to draw broad inferences from the empirical results.
A review of factors affecting carbon sequestration at green roofs
Authors: Wan Ismail Wan Zuriea , Abdullah Mat Naim , Che-Ani Adi Irfan
Published: October 2018

Purpose

This paper aims to assess factors that affect carbon sequestration on green roofs.

Design/methodology/approach

The most current academic literature related to carbon sequestration and green roofs carbon sequestration performance was reviewed.

Findings

Factors affecting carbon sequestration were discussed and classified into the following factors: plants, physical and maintenance factors. The authors’ findings are significant because they can be used to optimize green roofs performance for carbon sequestration.

Originality/value

Factors affecting carbon sequestration will optimize intensive green roofs performance.