bluuebunny/crossref_metadata_2025 huggingface dataset:
Alternative polyadenylation mediates genetic regulation of gene expression
Authors: Mittleman Briana , Pott Sebastian , Warland Shane , Zeng Tony , Kaur Mayher , Gilad Yoav , Li Yang I
Published: November 2019

With the exception of mRNA splicing, little is known about co-transcriptional or post-transcriptional regulatory mechanisms that link noncoding variation to variation in organismal traits. To begin addressing this gap, we used 3’ Seq to characterize alternative polyadenylation (APA) in the nuclear and total RNA fractions of 52 HapMap Yoruba lymphoblastoid cell lines, which we have studied extensively in the past. We identified thousands of polyadenylation sites that are differentially detected in nuclear mRNA and whole cell mRNA, and found that APA is an important mediator of genetic effects on gene regulation and complex traits. Specifically, we mapped 602 apaQTLs at 10% FDR, of which 152 were found only in the nuclear fraction. Nuclear-specific apaQTLs are highly enriched in introns and are also often associated with changes in steady-state expression levels, suggesting a widespread mechanism whereby genetic variants decrease mRNA expression levels by increasing usage of intronic PAS. We identified 24 apaQTLs associated with protein expression levels, but not mRNA expression, and found that eQTLs that are not associated with chromatin QTLs are enriched in apaQTLs. These findings support multiple independent pathways through which genetic effects on APA can impact gene regulation. Finally, we found that 19% of apaQTLs were also previously associated with disease. Thus, our work demonstrates that APA links genetic variation to variation in gene expression levels, protein expression levels, and disease risk, and reveals uncharted modes of genetic regulation.
Multi-differentiation potential is necessary for optimal tenogenesis of tendon stem cells
Authors: Rajpar Ibtesam , Barrett Jennifer G.
Published: November 2019

Background

Tendon injury is a significant clinical problem, and regenerative treatments are limited by our understanding of endogenous tendon stem cells. Recent evidence suggests that tendon stem cells are diverse in phenotypic character, and may in fact exist on a spectrum of differentiation capacities. However, the functional significance of each differentiation phenotype is poorly understood. Toward this end, we performed a comprehensive assessment of differentiation capacity toward four connective tissue lineages (adipose, bone, cartilage and tendon) with clonal tendon stem cell lines to: 1) evaluate the differences, if any, in tenogenic potential, and 2) identify the relationships in differentiation phenotype and proliferation capacity.

Methods

Tendon stem cells were derived from whole equine flexor tendons for this study (N=3). Clonal tendon stem lines were generated by low-density cell plating, and subjected to standard assays of tri-lineage differentiation and population doublings. For tenogenesis, a previously engineered three-dimensional hydrogel construct was incorporated. Differentiation was quantified by the relative gene expression of lineage-specific markers, and confirmed with lineage-specific cell staining. Tenogenesis was further analyzed by hydrogel contraction and histomorphometry. Statistical significance was determined using analysis of variance and post-hoc Tukey’s tests.

Results

Three distinct tendon stem cell phenotypes were identified, namely differentiation toward: 1) adipose, bone, cartilage and tendon, 2) bone, cartilage and tendon, or 3) adipose, cartilage and tendon. Further, a positive correlation was found in the ability to differentiate toward all four lineages and the generation of a robust, composite tendon-like construct upon tenogenesis, manifested by the strongest expressions of scleraxis and mohawk, and parallel alignment of tenocyte-like cells with elongated cell morphologies. Significantly increased numbers of cumulative cell population doublings were seen in the absence of adipogenic potential in clonal tendon stem cell lines.

Conclusions

Our study strengthens reports on the heterogeneous character of tendon stem cells and identifies key differences in their differentiation and proliferative potentials. Isolation of potent tendon stem cell populations from tendon stromal fractions may yield improved therapeutic benefits in clinical models of repair and promote a native, regenerative phenotype in engineered tendons. Future studies may be targeted to understanding the functional contributions of each tendon stem cell phenotypein vivo, and identifying additional cell phenotypes.
Structure of the human BBSome core complex in the open conformation
Authors: Klink Björn U. , Gatsogiannis Christos , Hofnagel Oliver , Wittinghofer Alfred , Raunser Stefan
Published: November 2019

The BBSome is a heterooctameric protein complex that plays a central role in primary cilia homeostasis. Its malfunction causes the severe ciliopathy Bardet-Biedl syndrome (BBS). The complex acts as a cargo adapter that recognizes signaling proteins such as GPCRs and links them to the intraflagellar transport machinery. The underlying mechanism is poorly understood. Here we present a high-resolution cryo-EM structure of a human heterohexameric core subcomplex of the BBSome. The structure reveals the architecture of the complex in atomic detail. It explains how the subunits interact with each other and how disease-causing mutations hamper this interaction. The complex adopts a conformation that is open for binding to membrane-associated GTPase Arl6 and a large positively charged patch likely strengthens the interaction with the membrane. A prominent negatively charged cleft at the center of the complex is likely involved in binding of positively charged signaling sequences of cargo proteins.
Different mechanisms for modulation of the initiation and steady-state of smooth pursuit eye movements
Authors: Behling Stuart , Lisberger Stephen G.
Published: November 2019

Smooth pursuit eye movements are used by primates to track moving objects. They are initiated by sensory estimates of target speed represented in the middle temporal (MT) area of extrastriate visual cortex and then supported by motor feedback to maintain steady-state eye speed at target speed. Here, we show that reducing the coherence in a patch of dots for a tracking target degrades the eye speed both at the initiation of pursuit and during steady-state tracking, when eye speed reaches an asymptote well below target speed. The deficits are quantitatively different between the motor-supported steady-state of pursuit and the sensory-driven initiation of pursuit, suggesting separate mechanisms. The deficit in visually-guided pursuit initiation could not explain the deficit in steady-state tracking. Pulses of target speed during steady-state tracking revealed lower sensitivities to image motion across the retina for lower values of dot coherence. However, sensitivity was not zero, implying that visual motion should still be driving eye velocity towards target velocity. When we changed dot coherence from 100% to lower values during accurate steady-state pursuit, we observed larger eye decelerations for lower coherences, as expected if motor feedback was reduced in gain. A simple pursuit model accounts for our data based on separate modulation of the strength of visual-motor transmission and motor feedback. We suggest that reduced dot coherence creates less reliable target motion that impacts pursuit initiation by changing the gain of visual-motor transmission and perturbs steady-state tracking by modulation of the motor corollary discharges that comprise eye velocity memory.
Quantification of the Resilience and Vulnerability of HIV-1 Native Glycan Shield at Atomistic Detail
Authors: Chakraborty Srirupa , Berndsen Zachary T. , Hengartner Nicolas W. , Korber Bette T. , Ward Andrew B. , Gnanakaran S.
Published: November 2019

Dense surface glycosylation on the HIV-1 envelope (Env) protein acts as a shield from the adaptive immune system. However, the molecular complexity and flexibility of glycans make experimental studies a challenge. Here we have integrated high-throughput atomistic modeling of fully glycosylated HIV-1 Env with graph theory to capture immunologically important features of the shield topology. This is the first complete all-atom model of HIV-1 Env SOSIP glycan shield that includes both oligomannose and complex glycans, providing results which are physiologically more relevant than the previous models with uniform glycosylation. This integrated approach including quantitative comparison with cryo-electron microscopy data provides hitherto unexplored details of the native shield architecture and its difference from the high-mannose glycoform. We have also derived a measure to quantify the shielding effect over the antigenic protein surface that defines regions of relative vulnerability and resilience of the shield and can be harnessed for rational immunogen design.
A Spectral De-mixing Model for Triplex In Vivo Imaging of Optical Coherence Tomography Contrast Agents
Authors: Yuan Edwin , Si Peng , Shevidi Saba , de la Zerda Adam
Published: November 2019

The ability to detect multiple contrast agents simultaneously would greatly enhance Optical Coherence Tomography (OCT) images, providing nuanced biological context to physiological structures. However, previous OCT contrast agent work has been limited to scenarios where only a single contrast agent could be robustly detected within each voxel. We present a novel spectroscopic technique for de-mixing the spectral signal from multiple OCT contrast agents within a single voxel. We validate our technique in vitro and also demonstrate in vivo imaging of three spectrally distinct gold nanobipyramids, trafficking within the lymphatic system of a live mouse. This approach opens the door to a much broader range of pre-clinical and clinical OCT applications where multiplexed labeling is desirable.
The Mitochondrial Iron Regulated (MIR) gene is Oryza genus-specific and evolved before the speciation of major AA-genome lineages
Authors: de Oliveira Ben-Hur Neves , Wairich Andriele , Turchetto-Zolet Andreia Carina , Fett Janette Palma , Ricachenevsky Felipe Klein
Published: November 2019

Rice (Oryza sativa L.) is both a model species and an economically relevant crop. The Oryza genus comprises 25 species, which constitute a genetic reservoir for cultivated rice breeding. Genomic data is available for several Oryza species, making it a good model for genetics and evolution within closely related species. The Mitochondrial Iron Regulated (MIR) gene was previously implicated in O. sativa Fe deficiency response, and was considered an orphan gene present only in rice. Here we show that MIR is also found in other Oryza species that belong to the AA genome group. We characterized the evolutionary pattern of MIR genes within the Oryza genus. Our data suggest that MIR originated de novo from non-coding sequences present only in AA genome species, but these sequences in turn are derived from an exon fragment of Raffinose Synthase genes, present in several groups of monocots. We also show that all species that have a putative functional MIR conserve their regulation by Fe deficiency, with the exception of Oryza barthii. In O. barthii, the MIR coding sequence was translocated to a different chromosomal position and separated from its regulatory region, which led to a lack of Fe deficiency responsiveness. Moreover, we show that MIR co-expression subnetwork cluster in O. sativa is responsive to Fe deficiency, evidencing the importance of the newly originated gene in Fe uptake. This work establishes that MIR is not an orphan gene as previously proposed, but a de novo originated gene within the Oryza genus. We also showed that MIR is undergoing genomic changes in at least one species (O. barthii), which can impact its role in Fe deficiency.
Propagation of THz irradiation energy through aqueous layers: Demolition of actin filaments in living cells
Authors: Yamazaki Shota , Harata Masahiko , Ueno Yuya , Tsubouchi Masaaki , Konagaya Keiji , Ogawa Yuichi , Isoyama Goro , Otani Chiko , Hoshina Hiromichi
Published: November 2019

The effect of terahertz (THz) radiation on deep tissues of human body has been considered negligible due to strong absorption by water molecules. However, we observed that the energy of THz pulses transmits a millimeter thick in the aqueous solution, possibly as a shockwave, and demolishes actin filaments. Collapse of actin filament induced by THz irradiation was also observed in the living cells under an aqueous medium. We also confirmed that the viability of the cell was not affected under the exposure of THz pulses. The potential of THz waves as an invasive method to alter protein structure in the living cells is demonstrated.

One sentence summary

The energy of the THz wave propagates several millimeters into an aqueous medium and demolishes actin filaments via shockwaves.
Structural insights into filament recognition by cellular actin markers
Authors: Kumari Archana , Kesarwani Shubham , Javoor Manjunath G , Vinothkumar Kutti R. , Sirajuddin Minhajuddin
Published: November 2019

Cellular studies of filamentous actin (F-actin) processes commonly utilize fluorescent versions of toxins, peptides and proteins that bind actin. While the choice of these markers has been largely based on availability and ease, there is a severe dearth of structural data for an informed judgment in employing suitable F-actin markers for a particular requirement. Here we describe the electron cryomicroscopy structures of phalloidin, lifeAct and utrophin bound to F-actin, providing the first high-resolution structures and comparison of widely used actin markers and their influence towards F-actin. Our results show that phalloidin binding does not induce conformations and lifeAct specifically recognizes ADP-actin state, which can be used as a sensor for distinguishing different nucleotide states of F-actin. The utrophin structural model aided designing minimal utrophin, which can be utilized as F-actin marker. Together, our study provides a structural perspective, where the binding sites of utrophin and lifeAct overlap with majority of actin binding proteins. Further offering an invaluable resource for researchers in choosing appropriate actin markers and generating new marker variants.
Association of Bacteroides acidifaciens relative abundance with high-fibre diet-associated radiosensitisation
Authors: Then Chee Kin , Paillas Salome , Wang Xuedan , Hampson Alix , Kiltie Anne E
Published: November 2019

Background

Patients with pelvic malignancies often receive radiosensitising chemotherapy with radiotherapy to improve survival, however this is at the expense of increased normal tissue toxicity, particularly in elderly patients. Here we explore if an alternative, low-cost and non-toxic approach can achieve radiosensitisation in mice transplanted with human bladder cancer cells. Other investigators have shown slower growth of transplanted tumours in mice fed high-fibre diets. We hypothesised that mice fed a high-fibre diet would have improved tumour control following ionising radiation (IR) and that this would be mediated through the gut microbiota.

Results

We investigated the effects of four different diets (low fibre, soluble high fibre, insoluble high fibre and mixed soluble/insoluble high fibre diets) on tumour growth in immunodeficient mice implanted with human bladder cancer flank xenografts and treated with ionising radiation, simultaneously investigating the composition of their gut microbiomes by 16S rRNA sequencing. A significantly higher relative abundance of Bacteroides acidifaciens was seen in the gut (faecal) microbiome of the soluble high fibre group, and the soluble high fibre diet resulted in delayed tumour growth after irradiation compared to the other groups. Within the soluble high fibre group, responders to irradiation had significantly higher abundance of B. acidifaciens than non-responders. When all mice fed with different diets were pooled, an association was found between the survival time of mice and relative abundance of B. acidifaciens. The gut microbiome in responders was predicted to be enriched for carbohydrate metabolism pathways and in vitro experiments on the transplanted human bladder cancer cell line suggested a role for microbial-generated short-chain fatty acids and/or other metabolites in the enhanced radiosensitivity of the tumour cells.

Conclusions

Soluble high fibre diets sensitised tumour xenografts to irradiation and this phenotype was associated with modification of the microbiome and positively correlated with B. acidifaciens abundance. Our findings might be exploitable for improving radiotherapy response in human patients.
A Hybrid Model for Predicting Pattern Recognition Receptors using Evolutionary Information
Authors: Kaur Dilraj , Arora Chakit , Raghava Gajendra P. S.
Published: November 2019

1.

This study describes a method developed for predicting pattern recognition receptors (PRRs), which are an integral part of the immune system. The models developed here were trained and evaluated on the largest possible non-redundant PRRs, and non-pattern recognition receptors (Non-PRRs) obtained from PRRDB 2.0. Firstly, a similarity-based approach using BLAST was used to predict PRRs and got limited success due to a large number of no-hits. Secondly, machine learning-based models were developed using sequence composition and achieved a maximum MCC of 0.63. In addition to this, models were developed using evolutionary information in the form of PSSM composition and achieved maximum MCC value of 0.66. Finally, we developed hybrid models that combined a similarity-based approach using BLAST and machine learning-based models. Our best model, which combined BLAST and PSSM based model, achieved a maximum MCC value of 0.82 with an AUROC value of 0.95, utilizing the potential of both similarity-based search and machine learning techniques. In order to facilitate the scientific community, we also developed a web server “PRRpred” based on the best model developed in this study (http://webs.iiitd.edu.in/raghava/prrpred/).
The Human Brain encodes a Chronicle of Visual Events at each Instant of Time
Authors: King J-R. , Wyart V.
Published: November 2019

The human brain continuously processes streams of visual input. Yet, a single image typically triggers neural responses that extend beyond one second. To understand how such a slow computation copes with real-time processing, we recorded subjects’ electrical brain activity, while they watched ~5,000 rapidly-changing images. First, we show that each image can be decoded from brain activity for ~1 sec, and demonstrate that the brain simultaneously represents multiple images at each time instant. Second, dynamical system modeling reveals that these sustained representations can be explained by a specific chain of neural circuits, which consist of (i) a hidden maintenance mechanism, and (ii) an observable update mechanism. Third, this neural architecture is localized along the expected visual pathways. Finally, we show that the propagation of low-level representations across the visual hierarchy is a principle shared with deep convolutional networks. Together, these findings provide a general neural mechanism to simultaneously represent successive visual events.

Significance

Our retina are continuously bombarded with a rich flux of visual input. How our brain continuously processes such visual stream is a major challenge to neuroscience. Here, we developed techniques to decode and track, from human brain activity, multiple images flashed in rapid succession. Our results show that the brain simultaneously represents multiple successive images at each time instant. A hierarchy of neural assemblies which continuously propagate multiple visual contents explains our findings. Overall, this study sheds new light on the biological basis of our visual experience.
Dynamical informational structures characterize the different human brain states of wakefulness and deep sleep
Authors: Galadí J. A. , Silva Pereira S. , Perl Y. S. , Kringelbach M.L. , Gayte I. , Laufs H. , Tagliazucchi E. , Langa J. A. , Deco G.
Published: November 2019

The dynamical activity of the human brain describes an extremely complex energy landscape changing over time and its characterisation is central unsolved problem in neuroscience. We propose a novel mathematical formalism for characterizing how the landscape of attractors sustained by a dynamical system evolves in time. This mathematical formalism is used to distinguish quantitatively and rigorously between the different human brain states of wakefulness and deep sleep. In particular, by using a whole-brain dynamical ansatz integrating the underlying anatomical structure with the local node dynamics based on a Lotka-Volterra description, we compute analytically the global attractors of this cooperative system and their associated directed graphs, here called the informational structures. The informational structure of the global attractor of a dynamical system describes precisely the past and future behaviour in terms of a directed graph composed of invariant sets (nodes) and their corresponding connections (links). We characterize a brain state by the time variability of these informational structures. This theoretical framework is potentially highly relevant for developing reliable biomarkers of patients with e.g. neuropsychiatric disorders or different levels of coma.
Ibotenic acid biosynthesis in the fly agaric is initiated by glutamate hydroxylation
Authors: Obermaier Sebastian , Müller Michael
Published: November 2019

The fly agaric, Amanita muscaria, is widely known for its content of the psychoactive metabolites ibotenic acid and muscimol. 50 years ago, their biosynthesis was hypothesized to start with 3-hydroxyglutamate. Here, we build on this hypothesis by the identification and recombinant production of a glutamate hydroxylase from A. muscaria. The corresponding gene is surrounded by six other genes, which we link to ibotenic acid production using recent genetic data. Our data provide new insights into a decades-old question concerning a centuries-old drug.
Perceived value, satisfaction and future intentions in sport services
Authors: Alguacil Mario , Núñez-Pomar Juan , Pérez-Campos Carlos , Prado-Gascó Vicente
Published: November 2019

Purpose

The purpose of this paper is to analyze the role of brand-related variables as congruence and brand trust on the traditional model formed by perceived quality, perceived value (PV) and satisfaction, in order to compare predictive models for the variables of PV, satisfaction and future intentions of 683 users of sports services.

Design/methodology/approach

The analysis has been carried out using two different methodologies. First, three models have been proposed to be analyzed by hierarchical regression models, in order to subsequently propose a fuzzy-set qualitative comparative analysis (fsQCA) to verify the existence or not of necessary and sufficient conditions.

Findings

The results indicate that both the classic service variables and the elements related to the brand significantly predict PV, satisfaction and future intentions, in some cases with greater predictive weight being given to congruence and trust than the classic service variables. In addition, linear models have been shown to improve their predictive capability by including brand-related variables, especially the future intentions model. After the fsQCA, congruence and trust have proved to be sufficient combinations to achieve high levels of PV and future intentions, while this is not the case for satisfaction.

Originality/value

The importance of the aspects related to the brand, either on their own or in combination with the classic service variables, is demonstrated, contributing to the literature on brand image in sports services, which is practically non-existent.
A systematic literature review on BPMN extensions
Authors: Zarour Karim , Benmerzoug Djamel , Guermouche Nawal , Drira Khalil
Published: November 2019

Purpose

Business Process Model and Notation (BPMN) is a generic language that is often extended by researchers, either for dealing with processes of specific domains or for improving the language itself. The purpose of this paper is to present a literature review that aims to determine the current state of the art of BPMN extensions and identify the gaps that should be filled in this research area.

Design/methodology/approach

For a comprehensive and effective analysis, a systematic literature review was conducted. After the collection and filtering of papers, 52 extensions were retained to be thoroughly examined and compared according to a set of criteria including objective, targeted domain, conformity to the extension mechanism, demonstration, implementation, etc.

Findings

The representation of the results in the form of tables and graphs allowed the authors to deduce several positive points on the extensions as their demonstration through concrete examples. On the other hand, the authors have observed several shortcomings and suggested recommendations for addressing them.

Originality/value

To the best of the authors’ knowledge, the literature review is the only one that evaluates and compares all BPMN extensions over the last four years, based on several criteria covering different aspects. Furthermore, the authors were able to verify the conformity of extensions as they were published after the introduction of the BPMN extension mechanism by the Object Management Group.
Analysis of squirrel-cage induction generator start-up supported by reactive power compensator
Authors: Górski Dominik Andrzej
Published: November 2019

Purpose

The power electronic converter is used for the satisfaction of reactive power demand of induction generator, when grid-tied. This paper aims to present an application of STATCOM to reduce inrush transient caused by the connection of a squirrel-cage induction generator (SCIG) to the grid.

Design/methodology/approach

The power generation system consists of an uncontrolled prime mover, a SCIG and a power electronic converter connected to the grid. The three-phase Neutral Point Clamped (NPC) converter works as a STATCOM to satisfy a reactive power demand of the generator. A control scheme of STATCOM uses the x-y reference frame rotating synchronously with grid voltage vector and the p-q instantaneous power theory to calculate q component of grid power.

Findings

It is shown that the parallel converter, which works as a reactive power compensator allows decreasing transients during a grid connection of the induction generator.

Research limitations/implications

Transients during a grid connection of the induction generator are only partially decreased.

Practical implications

It is needed to compensate for the reactive power of a SCIG. The NPC converter works as a STATCOM. The converter partially reduces grid transients during generator connection. The laboratory tests are demonstrated by connection 7.5 kW induction generator to 8 kVA transformer.

Originality/value

The paper presents the mitigation of grid transients during connection of induction generator with the power electronic converter working as reactive power compensator.
A sequential sampling method for adaptive metamodeling using data with highly nonlinear relation between input and output parameters
Authors: Huo Guanying , Jiang Xin , Zheng Zhiming , Xue Deyi
Published: November 2019

Purpose

Metamodeling is an effective method to approximate the relations between input and output parameters when significant efforts of experiments and simulations are required to collect the data to build the relations. This paper aims to develop a new sequential sampling method for adaptive metamodeling by using the data with highly nonlinear relation between input and output parameters.

Design/methodology/approach

In this method, the Latin hypercube sampling method is used to sample the initial data, and kriging method is used to construct the metamodel. In this work, input parameter values for collecting the next output data to update the currently achieved metamodel are determined based on qualities of data in both the input and output parameter spaces. Uniformity is used to evaluate data in the input parameter space. Leave-one-out errors and sensitivities are considered to evaluate data in the output parameter space.

Findings

This new method has been compared with the existing methods to demonstrate its effectiveness in approximation. This new method has also been compared with the existing methods in solving global optimization problems. An engineering case is used at last to verify the method further.

Originality/value

This paper provides an effective sequential sampling method for adaptive metamodeling to approximate highly nonlinear relations between input and output parameters.
Entropy generation analysis in flow of thixotropic nanofluid
Authors: Ijaz Khan Muhammad , Ahmad Salman , Hayat Tasawar , Khan M. Waleed Ahmad , Alsaedi Ahmed
Published: November 2019

Purpose

The purpose of this paper is to address entropy generation in flow of thixotropic nonlinear radiative nanoliquid over a variable stretching surface with impacts of inclined magnetic field, Joule heating, viscous dissipation, heat source/sink and chemical reaction. Characteristics of nanofluid are described by Brownian motion and thermophoresis effect. At surface of the sheet zero mass flux and convective boundary condition are considered.

Design/methodology/approach

Considered flow problem is mathematically modeled and the governing system of partial differential equations is transformed into ordinary ones by using suitable transformation. The transformed ordinary differential equations system is figure out by homotopy algorithm. Outcomes of pertinent flow variables on entropy generation, skin friction, concentration, temperature, velocity, Bejan, Sherwood and Nusselts numbers are examined in graphs. Major outcomes are concluded in final section.

Findings

Velocity profile increased versus higher estimation of material and wall thickness parameter while it decays through larger Hartmann number. Furthermore, skin friction coefficient upsurges subject to higher values of Hartmann number and magnitude of skin friction coefficient decays via materials parameters. Thermal field is an increasing function of Hartmann number, radiation parameter, thermophoresis parameter and Eckert number.

Originality/value

The authors have discussed entropy generation in flow of thixotropic nanofluid over a variable thicked surface. No such consideration is yet published in the literature.
Research on properties of modified nylon blend yarn and fabric
Authors: Liu Xinjin , Su Xuzhong , Song Juan , Zhang Yafang
Published: November 2019

Purpose

Due to the excellent functionality of graphene, the research on fiber modification by graphene has been receiving more and more attentions recently, and many research findings have been conducted. However, the purpose of this paper is to focus on the fiber modification method and corresponding modified fiber properties, but the research on processing of the modified fiber, especially the textile process, is little. Therefore, in the paper, the properties of one kind of textile GN fiber and the spinning method of the GN fiber blend yarn and the functionalities of corresponding fabric are studied.

Design/methodology/approach

In the paper, the properties of nylon fiber modified by graphene (GN) were studied first. Then, according to the tested results, one new blending process of the GN fiber and cotton fiber was given, and corresponding properties of the blend yarns were tested and analyzed. Finally, the knitted fabrics were produced using the spun blend yarns, and the antibacterial property, electromagnetic shielding property, anti-ultraviolet performance, anti-static performance and conventional mechanical, and appearance thermal-wet comfort properties were tested and comparatively analyzed.

Findings

The tested results showed that the functionality of all fabrics was effective due to the addition of the graphene in the fiber, especially the antibacterial property. With the increasing of the GN fiber in the blend yarns, the functionality of all fabrics was also increased first and then achieved stability.

Originality/value

One new blending process of the GN fiber and cotton fiber was given. In the spinning, the combed cotton sliver was produced first, and then was torn into small parts of combed cotton sliver fiber by hand. Then, the treated GN fibers and cotton fibers were mixed for the first time, and corresponding GN/C carding sliver was produced. In this blend processing, the mixed cotton fiber was used to improve the sliver processing of the GN fiber. Then, in the drawing process, the required number of GN/C carding sliver and combed cotton sliver were fed simultaneously, and GN fibers and cotton fibers were mixed for the second time, and corresponding four kinds of GN/JC blend yarns were produced. In this blend processing, the mixed cotton fiber was used to regulate the blending ratio.
The effect of green shipping practices on multinational companies’ loyalty in Malaysia
Authors: Jozef Erwind , Kumar Kavigtha Mohan , Iranmanesh Mohammad , Foroughi Behzad
Published: November 2019

Purpose

The globalization of market and production activities with unequal distribution of market demand and resources has accelerated the demand for shipping services. Public concerns about environmental issues and the impacts of shipping service providers’ green shipping practices (GSPs) on the reputation and performance of multinational companies (MNCs) motivated the authors to test the impact of shipping companies’ GSPs on MNCs’ loyalty by considering timeliness and perceived value as moderators. The paper aims to discuss this issue.

Design/methodology/approach

The data were collected from 141 MNCs and analyzed using the partial least squares technique.

Findings

The results show that company policy and procedure, shipping documentation, shipping equipment and shipping materials have significant effects on MNCs’ loyalty. Furthermore, timeliness positively moderates the impacts of shipping materials and shipping design on compliance, while perceived value positively moderates the effects of shipping equipment and shipping design for compliance on MNCs’ loyalty.

Practical implications

The results provide insight for shipping service providers on GSPs that may lead to MNCs’ loyalty by considering the roles of lead time and freight rate.

Originality/value

The results extend the literature by testing empirically the impacts of GSP of shipping companies on MNCs’ loyalty and also by investigating the moderating impacts of perceived value and timeliness.
Air pollution and public finance: evidence for European countries
Authors: Carratù Maria , Chiarini Bruno , D’Agostino Antonella , Marzano Elisabetta , Regoli Andrea
Published: November 2019

Purpose

The purpose of this paper is to investigate whether a statistically significant relationship exists between environmental quality, as measured by consumption-related air pollution, and public debt in Europe. In addition, since the debt burden is one of the most important indicators of fiscal soundness within the European Union (EU) Treaty and the subsequent fiscal compact, the authors propose a simple test to determine whether participation in EU Treaties has shaped the empirical relationship between fiscal policy/public debt and environmental performance.

Design/methodology/approach

To this end, the authors built a panel data set that covers 24 European countries over the period 1996–2015.

Findings

The aspect that the authors want to underline is a possible trade off, which is confirmed in the empirical analysis, between the public finance equilibrium and the maintenance of a public good such as air quality. However, there are important non-linearities that shape the interaction between public debt and environmental pollution. Similarly, threshold effects arise when the authors examine the interaction between EU regulation and public debt and when the authors separately examine high debt and low debt countries. When the authors account for the stabilization rules introduced by EU Treaties, a negative effect on pollution is evident; in this way, fiscal consolidation limits the positive effect of fiscal policy.

Practical implications

The results point out the existence of a potential trade-off between the role of EU as a regulator aiming to mitigate environmental pollution, and its role within the Stability and Growth Pact. The analysis highlights that fiscal consolidation policies, while facilitating the achievement of macroeconomic stability within EU, might have a negative side effect on the environment quality, which spreads beyond the borders of one single country.

Originality/value

While a number of studies have suggested that fiscal spending might contribute to the level of pollution in European countries, there is scant evidence of the effect of public debt on environmental performance. This lack of scientific knowledge is a serious shortcoming, since it may allow for an underrepresentation of the wide-ranging consequences of stabilization programmes targeting the debt-to-GDP ratio, which could affect environmental quality.
The long-run interrelationship between exchange rate and interest rate: the case of Mexico
Authors: Capasso Salvatore , Napolitano Oreste , Viveros Jiménez Ana Laura
Published: November 2019

Purpose

The purpose of this paper is to analyse the long-term nature of the interrelationship between interest rate and exchange rate.

Design/methodology/approach

By employing Mexican data, the authors estimate a non-linear autoregressive distributed lags (NARDL) model to investigate the nature of the changes and the interaction between interest rate and exchange rate in response to monetary authorities’ actions.

Findings

The results show that, contrary to simplistic predictions, the real exchange rate causes the real interest rate in an asymmetric way. The bounds testing approach of the NARDL models suggests the presence of co-integration among the variables and the exchange rate variations appear to have significant long-run effects on the interest rate. Most importantly, these effects are asymmetric and positive variations in the exchange rate have a lower impact on the interest rate. It is also interesting to report that the reverse is not true: the interest rate in the long-run exerts no statistical significant impact on the exchange rate.

Practical implications

The asymmetric long-term relationship between real exchange rate and real interest rate is evidence of why monetary authorities are reluctant to free float exchange rate. In Mexico, as in most developing countries, monetary policy strongly responds to exchange rate movements because these have relevant effects on commercial trade. Moreover, in dollarized economies these effects are stronger because of pass-through impacts to inflation, income distribution and balance-sheet equilibrium (the well-known “original sin”).

Originality/value

Under inflation targeting and flexible exchange rate regime, despite central banks pursue the control of short-term interest rate, in the long-run one could observe that it is the exchange rate that influences the interest rate, and that this reverse causality is stronger in emerging economies. This paper contributes by analysing the asymmetric relationship between the variables.
Macroeconomic effects of consumer confidence shock – evidence for state dependence
Authors: Ahmad Nazneen , Rangaraju Sandeep Kumar
Published: November 2019

Purpose

The purpose of this paper is to investigate the impact of a consumer confidence shock on GDP and different types of consumer spending during a slack state as well as a non-slack state of an economy.

Design/methodology/approach

The authors use the US quarterly data from 1960Q1 to 2014Q4 and apply Jorda’s (2005) local projection method to compute the impulse responses of macroeconomic variables to a consumer confidence shock. The local projection method allows us to include non-linearities in the response function.

Findings

In general, the response of output, following a consumer confidence shock, is similar in slack and non-slack states and indicate that an unfavorable confidence shock is contractionary. However, the intensity and duration of impact of a confidence shock on different components of spending are state dependent. Overall, a negative confidence shock appears to have a stronger impact on non-slack time than on a slack time.

Practical implications

Policy makers should be careful about undertaking a policy action that may affect consumer confidence adversely, particularly during an economic good time. An adverse confidence shock can trigger a downfall in a well-functioning economy and the dampening effect may last for several quarters before the economy rebounds.

Originality/value

US economy is subject to fluctuations; however, the literature on the impact of confidence shock in different economic states is limited. The incremental contribution of this paper is that it investigates how the consumers respond to the confidence shock in a state-dependent model. Furthermore, the authors use a more robust and alternative estimation method that tackles any non-linear problems.
Liquidity in the UAE Islamic banks
Authors: ElMassah Suzanna , AlSayed Ola , Bacheer Shereen Mostafa
Published: November 2019

Purpose

The purpose of this study is to investigate the main factors that affect liquidity risk in the UAE Islamic banks.

Design/methodology/approach

The study examines the annual data of the seven UAE Islamic banks over the period 2008-2014. Random effects panel data model is used to estimate the impact of four bank-specific variables and two macroeconomic ones on the liquidity risk of the UAE Islamic banks via their impact on five alternative liquidity ratios.

Findings

The paper finds that bank size has a negative impact on liquidity risk according to two liquidity ratios only, and an insignificant impact according to the other three. Both capital adequacy and London interbank offered rate have significant negative impacts on liquidity risk for three liquidity ratios, and insignificant impacts on two. The effect of credit risk is negative for all adopted ratios, while that of return on assets is negative for one ratio only. Finally, real GDP has a positive effect on two ratios and an insignificant one on the others.

Research limitations/implications

The study provides insights for policymakers and practitioners to choose appropriate liquidity management procedures. It emphasizes that identifying efficient procedures or policies depends on the liquidity ratio that is used as a proxy of liquidity risk and its definition, in addition to the correlation between the liquidity ratio and liquidity risk. The study also provides some guidance to Islamic banks in the UAE concerning the main factors impacting their liquidity, which can eventually enable them to support their liquidity management policies, in a way that would expand their customer base according to profitability aspects, and not only religious ones.

Originality/value

The paper adds to the relatively limited literature on liquidity risk in Islamic banks. It also is the first study that investigates the determinants of liquidity risk facing Islamic banks in the UAE using five alternative liquidity ratios.
Risk and returns inShari’ah-compliant cross-section stocks: evidence from an emerging market
Authors: Hanif Muhammad , Iqbal Abdullah , Shah Zulfiqar
Published: November 2019

Purpose

This study aims to understand and document the impact of market-based – market returns and momentum – as well as firm-specific – size, book-to-market (B/M) ratio, price-to-earnings ratio (PER) and cash flow (CF) – factors on pricing ofShari’ah-compliant securities as explanation of variations in stock returns in an emerging market – Pakistan’s Karachi Stock Exchange.

Design/methodology/approach

Initially, the authors test Fama and French (FF) three-factor model – market risk premium, size and B/M – followed by modified FF model by including additional risk factors (PER, CF and momentum) over a 10-year period (2001-2010).

Findings

Our results support superiority of FF three-factor model over single-factor capital asset pricing model. However, addition of further risk factors – including PER, CF and momentum – improves explanatory power of the model, as well as refines the selection of risk factors. In this study, CF, B/M and momentum factors remain insignificant. Traditional B/M factor in FF model is replaced by PER.

Practical implications

Based on the modified FF model, the authors propose a stock valuation model forShari’ah-compliant securities consisting of three factors: market returns, size and earnings, which explains 76per cent variations in cross sectional stock returns.

Originality/value

To the best of the authors’ knowledge, this is the first study (which combines market-based as well as fundamental factors) on pricing of Islamic securities and identification of risk factors in an emerging market – Karachi Stock Exchange.
Linking governance qualities and stewardship attributes: findings from Malaysian takaful operators
Authors: Muhamat Amirul Afif , McIver Ronald
Published: November 2019

Purpose

As custodians of takaful contributors’ tabarru’ (donation) funds, takaful operators are expected to fulfil a stewardship role propagated under the precepts of Islam. The purpose of this paper is to analyse takaful operators’ stewardship, focusing on investment practices.

Design/methodology/approach

Structured interviews were conducted with senior investment staff from all of Malaysia’s takaful operators. Questions, developed using Delphi-style techniques, allowed a five-point Likert scale response addressing specific issues revolving around seven dimensions of governance quality – using the Malaysian Rating Corporation’s (MARC’s) governance rating guidelines for Islamic financial institutions (IFIs). Interviewees’ responses were assigned composite scores.

Findings

Malaysia’s takaful operators score well on most prescribed governance quality dimensions, although performance varies between operators and across dimensions. Areas for improvement are identified, especially regarding disclosure of information and contributor involvement in takaful operators’ management.

Research limitations/implications

Predetermined questions restrict flexibility in obtaining takaful operators’ information; however, end-of-interview, open-ended questions were asked to tap interviewee opinions on pertinent issues. A focus on takaful operators’ governance quality and stewardship of investments means findings may not be representative of all operational aspects of their businesses.

Practical implications

This study identifies governance quality guidelines which takaful operators may benchmark against and identifies where best to focus attempts to improve performance. These guidelines will also assist regulators assessing takaful operators’ stewardship performance.

Originality/value

This study uses governance quality as an indicator of stewardship, a concept aligned with the precepts of Shariah. It covers the opinion of the takaful industry in a country with a comprehensive Islamic financial system, Malaysia, extending understanding of takaful operators’ governance quality.