bluuebunny/crossref_metadata_2025 huggingface dataset:
Modulation of β-amyloid aggregation by graphene quantum dots
Authors: Liu Changliang , Huang Huan , Ma Lilusi , Fang Xiaocui , Wang Chen , Yang Yanlian
Published: June 2019

Misfolding and abnormal aggregation of β-amyloid peptide is associated with the onset and progress of Alzheimer's disease (AD). Therefore, modulating β-amyloid aggregation is critical for the treatment of AD. Herein, we studied the regulatory effects and mechanism of graphene quantum dots (GQDs) on 1–42 β-amyloid (Aβ
1–42
) aggregation. GQDs displayed significant regulatory effects on the aggregation of Aβ
1–42
peptide as detected by thioflavin T (ThT) assay. Then, the changes of confirmations and structures induced by GQDs on the Aβ
1–42
aggregation were monitored by circular dichroism (CD), dynamic light scattering (DLS) and transmission electron microscope (TEM). The
in vitro
cytotoxicity experiments further demonstrated the feasibility of GQDs on the regulation of Aβ
1–42
aggregation. Meanwhile, the structural changes of a Aβ
1–42
/GQDs mixture in different pH revealed that electrostatic interaction was the major driving force in the co-assembly process of Aβ
1–42
and GQDs. The proposed mechanism of the regulatory effects of GQDs on the Aβ
1–42
aggregation was also deduced reasonably. This work not only demonstrated the potential feasibility of GQDs as therapeutic drug for AD but also clarified the regulatory mechanism of GQDs on the Aβ
1–42
aggregation.
Patterns, dynamics and consequences of microplastic ingestion by the temperate coral,
Astrangia poculata
Authors: Rotjan Randi D. , Sharp Koty H. , Gauthier Anna E. , Yelton Rowan , Lopez Eliya M. Baron , Carilli Jessica , Kagan Jonathan C. , Urban-Rich Juanita
Published: June 2019

Microplastics (less than 5 mm) are a recognized threat to aquatic food webs because they are ingested at multiple trophic levels and may bioaccumulate. In urban coastal environments, high densities of microplastics may disrupt nutritional intake. However, behavioural dynamics and consequences of microparticle ingestion are still poorly understood. As filter or suspension feeders, benthic marine invertebrates are vulnerable to microplastic ingestion. We explored microplastic ingestion by the temperate coral
Astrangia poculata
. We detected an average of over 100 microplastic particles per polyp in wild-captured colonies from Rhode Island. In the laboratory, corals were fed microbeads to characterize ingestion preference and retention of microplastics and consequences on feeding behaviour. Corals were fed biofilmed microplastics to test whether plastics serve as vectors for microbes. Ingested microplastics were apparent within the mesenterial tissues of the gastrovascular cavity. Corals preferred microplastic beads and declined subsequent offerings of brine shrimp eggs of the same diameter, suggesting that microplastic ingestion can inhibit food intake. The corals co-ingested
Escherichia coli
cells with microbeads. These findings detail specific mechanisms by which microplastics threaten corals, but also hint that the coral
A. poculata
, which has a large coastal range, may serve as a useful bioindicator and monitoring tool for microplastic pollution.
Long-lasting vocal plasticity in adult marmoset monkeys
Authors: Zhao Lingyun , Rad Bahar Boroumand , Wang Xiaoqin
Published: June 2019

Humans exhibit a high level of vocal plasticity in speech production, which allows us to acquire both native and foreign languages and dialects, and adapt to local accents in social communication. In comparison, non-human primates exhibit limited vocal plasticity, especially in adulthood, which would limit their ability to adapt to different social and environmental contexts in vocal communication. Here, we quantitatively examined the ability of adult common marmosets (
Callithrix jacchus
), a highly vocal New World primate species, to modulate their vocal production in social contexts. While recent studies have demonstrated vocal learning in developing marmosets, we know much less about the extent of vocal learning and plasticity in adult marmosets. We found, in the present study, that marmosets were able to adaptively modify the spectrotemporal structure of their vocalizations when they encountered interfering sounds. Our experiments showed that marmosets shifted the spectrum of their vocalizations away from the spectrum of the interfering sounds in order to avoid the overlap. More interestingly, we found that marmosets made predictive and long-lasting spectral shifts in their vocalizations after they had experienced a particular type of interfering sound. These observations provided evidence for directional control of the vocalization spectrum and long-term vocal plasticity by adult marmosets. The findings reported here have important implications for the ability of this New World primate species in voluntarily and adaptively controlling their vocal production in social communication.
Reflections from an old Queenslander: can rear and release strategies be the next great era of vector control?
Authors: Ritchie Scott A. , Staunton Kyran M.
Published: June 2019

In this perspective, I discuss the great eras of vector control, centring on
Aedes aegypti
, the primary vector of dengue, Zika and several other viruses. Since the discovery and acceptance of the role of mosquitoes as vectors of disease agents, several significant strategies have been developed and deployed to control them and the diseases they transmit. Environmental management, insecticides and, to a lesser extent, biological control have emerged as great eras of vector control. In the past decade, the release of massive numbers of specifically modified mosquitoes that mate with wild populations has emerged as a significant new strategy to fight vector-borne diseases. These reared and released mosquitoes have been modified by the addition of a symbiont (e.g.
Wolbachia
bacteria), radiation or introduction of a genetic construct to either sterilize the wild mosquitoes they mate with, crashing the population, or to reduce the wild population's capacity to vector pathogens. Will these new rear and release strategies become the next great era of vector control? From my vantage point as a dengue control manager and researcher involved in two
Wolbachia
programmes, I will discuss the hurdles that rear and release programmes face to gain widespread acceptance and success.
Developmental plasticity of cardiac anoxia-tolerance in juvenile common snapping turtles (Chelydra serpentina)
Authors: Ruhr Ilan M. , McCourty Heather , Bajjig Afaf , Crossley Dane A. , Shiels Holly A. , Galli Gina L. J.
Published: June 2019

For some species of ectothermic vertebrates, early exposure to hypoxia during embryonic development improves hypoxia-tolerance later in life. However, the cellular mechanisms underlying this phenomenon are largely unknown. Given that hypoxic survival is critically dependent on the maintenance of cardiac function, we tested the hypothesis that developmental hypoxia alters cardiomyocyte physiology in a manner that protects the heart from hypoxic stress. To test this hypothesis, we studied the common snapping turtle, which routinely experiences chronic developmental hypoxia and exploits hypoxic environments in adulthood. We isolated cardiomyocytes from juvenile turtles that embryonically developed in either normoxia (21% O2) or hypoxia (10% O2), and subjected them to simulated anoxia and reoxygenation, while simultaneously measuring intracellular Ca2+, pH and reactive oxygen species (ROS) production. Our results suggest developmental hypoxia improves cardiomyocyte anoxia-tolerance of juvenile turtles, which is supported by enhanced myofilament Ca2+-sensitivity and a superior ability to suppress ROS production. Maintenance of low ROS levels during anoxia might limit oxidative damage and a greater sensitivity to Ca2+could provide a mechanism to maintain contractile force. Our study suggests developmental hypoxia has long-lasting effects on turtle cardiomyocyte function, which might prime their physiology for exploiting hypoxic environments.
Dysosmobacter welbionis gen. nov., sp. nov., isolated from human faeces and emended description of the genus Oscillibacter
Authors: Le Roy Tiphaine , Van der Smissen Patrick , Paquot Adrien , Delzenne Nathalie , Muccioli Giulio G. , Collet Jean-François , Cani Patrice D.
Published: June 2019

A strictly anaerobic, Gram-stain-negative, non-spore-forming, non-motile, non-pigmented bacterium, strain J115T, was isolated from human faeces. Cells of strain J115T were straight rods, generally 1.8–3.0 µm, but could be up to 18 µm long. Growth occurred below 2 % (w/v) NaCl and 2 % (v/v) bile. Strain J115T produced acid from myo-inositol but not from d-glucose, d-ribose or d-xylose. Butyric acid was the major end-product from myo-inositol. The genomic DNA G+C content was 58.92 mol%. Phylogenetic analysis based on 16S rRNA gene sequencing indicated that the closest cultivated neighbours of strain J115T were

Oscillibacter ruminantium

GH1T (95.4 % similarity) and

Oscillibacter valericigenes

Sjm18-20T (94.1 %). Strain J115T was also related to the not-yet-cultured bacterium

Oscillospira guilliermondii

(92–93 % similarity). Coherently with the 16S rRNA gene sequence results, the ANI scores don't have units of strain J115T to

O. ruminantium

GH1T and

O. valericigenes

Sjm18-20T were 73.37 and 73.24, respectively, while in silico estimations of DNA–DNA hybridization were both 20.4 %, with confidence intervals of 18.2–22.9 % and 18.2–22.8 %, respectively. The major fatty acids were iso-C15 : 0 (24.2 %), C18 : 0 DMA (18.4 %), anteiso-C15 : 0 (15.2 %) and C16 : 0 DMA (7.6 %). No respiratory quinone was detected. Based on phenotypic features and phylogenetic position, it is proposed that this isolate represents a novel species in a new genus, Dysosmobacter welbionis gen. nov., sp. nov. The type strain of Dysosmobacter welbionis is J115T (DSM 106889T=LMG 30601T).
Genome-wide postnatal changes in immunity following fetal inflammatory response
Authors: Costa Daniel , Bonet Núria , Solé Amanda , de Aledo-Castillo José Manuel González , Sabidó Eduard , Casals Ferran , Rovira Carlota , Nadal Alfons , Marin Jose Luis , Cobo Teresa , Castelo Robert
Published: June 2019

The fetal inflammatory response (FIR) increases the risk of perinatal brain injury, particularly in extremely low gestational age newborns (ELGANs, < 28 weeks of gestation). One of the mechanisms contributing to such a risk is a postnatal intermittent or sustained systemic inflammation (ISSI) following FIR. The link between prenatal and postnatal systemic inflammation is supported by the presence of well-established inflammatory biomarkers in the umbilical cord and peripheral blood. However, the extent of molecular changes contributing to this association is unknown. Using RNA sequencing and mass spectrometry proteomics, we profiled the transcriptome and proteome of archived neonatal dried blood spot (DBS) specimens from 21 ELGANs. Comparing FIR-affected and unaffected ELGANs, we identified 782 gene and 27 protein expression changes of 50% magnitude or more, and an experiment-wide significance level below 5% false discovery rate. These expression changes confirm the robust postnatal activation of the innate immune system in FIR-affected ELGANs and reveal for the first time an impairment of their adaptive immunity. In turn, the altered pathways provide clues about the molecular mechanisms triggering ISSI after FIR, and the onset of perinatal brain injury.
Electrocardiographic Changes After Completion of a Triathlon
Authors: Hosatte-Ducassy Caroline , Correa José A. , Lalonde François , Mohindra Rohit , Marton Gregory , Chetrit Michael , Marcotte Audrey , Tournoux François , Bridges Eileen
Published: June 2019

Objectives

Given the increasing popularity of long-distance triathlon events amongst amateur athlete and the difficulty for emergency physician to address cardiovascular complaints in the context of exercise, this study aims to:

-

Identify the prevalence of electrocardiographic abnormalities before and after a long distance triathlon in a cohort of participants using the Seattle criteria.

-

Identify the acute changes that occur on their ECGs at the finish line of a long-distance triathlon.

Methods

This prospective observational study examines the prevalence of selected standard 12-lead ECG findings, the Seattle criteria, in asymptomatic athletes before and after the completion of a long-distance triathlon.

Results

Of 99 ECGs obtained prior to the race, 28 were abnormal, for a pre-race prevalence of 28.3% (95% CI (20.4, 37.8)). Of the 72 ECGs post-race, 12 were abnormal, for a post-race prevalence of 16.7% (95% CI (9.8, 26.9)). We did not observe any athletes with marked repolarization abnormalities.

Common findings were increased QRS voltage significant for left ventricular hypertrophy (LVH) (24 (24.2%) pre-race, 10 (14.1%) post-race), early repolarization (21 (21.2%) pre-race, 19 (26.8%) post-race) and incomplete right bundle branch block (RBBB) (8 (8.1%) pre-race, 11 (15.5%) post-race).

McNemar’s test showed no agreement between the ECG pre and post results (Chi-square =6.54, p = 0.01), suggesting a possible effect of the race on ECG findings. We observed a trend to normalization of athlete’s ECGs with acute exercise.

Conclusion

Long-distance endurance exercise might acutely affect the ECGs findings in asymptomatic athletes and abnormal ECG findings were common in our cohort of athletes. Physicians providing care to long-distance athletes should interpret ECGs in this population prudently.

SUMMARY BOX

The acute effect of exercises on athlete’s electrocardiograms has not been well studied.

In our cohort of long-distance triathlon finishers, 28.3% of athletes had abnormal ECGs pre-race and 16.7% had abnormal ECGs post-race according to the Seattle Criteria. We observed a trend toward normalization of athlete’s ECGs with acute exercise.

Common ECGs abnormalities found in those asymptomatic athletes were left ventricular hypertrophy, early repolarization and right bundle branch block.

Physicians involved in the care of athletes should be prudent when interpreting ECGs in this population.
Serum Amyloid A Proteins Induce Pathogenic TH17 Cells and Promote Inflammatory Disease
Authors: Lee June-Yong , Hall Jason A. , Kroehling Lina , Wu Lin , Najar Tariq , Nguyen Henry H. , Lin Woan-Yu , Yeung Stephen T. , Silva Hernandez Moura , Li Dayi , Hine Ashley , Loke P’ng , Hudesman David , Martin Jerome C. , Kenigsberg Ephraim , Merad Miriam , Khanna Kamal M. , Littman Dan R.
Published: June 2019

Lymphoid cells that produce IL-17 cytokines protect barrier tissues from pathogenic microbes, but are also prominent effectors of inflammation and autoimmune disease. T-helper (TH17) cells, defined by RORγt-dependent production of IL-17A and IL-17F, exert homeostatic functions in the gut upon microbiota-directed differentiation from naïve CD4+ T cells. In the non-pathogenic setting, their cytokine production is regulated by serum amyloid A proteins (SAA1 and SAA2) secreted by adjacent intestinal epithelial cells. However, TH17 cell behaviors vary markedly according to their environment. Here we show that SAAs additionally direct a pathogenic pro-inflammatory TH17 cell differentiation program, acting directly on T cells in collaboration with STAT3-activating cytokines. Using loss- and gain-of-function mouse models, we show that SAA1, SAA2, and SAA3 have distinct systemic and local functions in promoting TH17-mediated inflammatory diseases. These studies suggest that T cell signaling pathways modulated by the SAAs may be attractive targets for anti-inflammatory therapies.
From drift to draft: How much do beneficial mutations actually contribute to predictions of Ohta’s slightly deleterious model of molecular evolution?
Authors: Chen Jun , Glémin Sylvain , Lascoux Martin
Published: June 2019

Since its inception in 1973 the slightly deleterious model of molecular evolution, aka the Nearly Neutral Theory of molecular evolution, remains a central model to explain the main patterns of DNA polymorphism in natural populations. This is not to say that the quantitative fit to data is perfect. In a recent study Castellanoet al.(2018) used polymorphism data fromD. melanogasterto test whether, as predicted by the Nearly Neutral Theory, the proportion of effectively neutral mutations depends on the effective population size (Ne). They showed that a nearly neutral model simply scaling with Nevariation across the genome could not explain alone the data but that consideration of linked positive selection improves the fit between observations and predictions. In the present article we extended their work in two main directions. First, we confirmed the observed pattern on a set of 59 species, including high quality genomic data from 11 animal and plant species with different mating systems and effective population sizes, hencea prioridifferent levels of linked selection. Second, for the 11 species with high quality genomic data we also estimated the full Distribution of Fitness Effects (DFE) of mutations, and not solely the DFE of deleterious mutations. Both Neand beneficial mutations contributed to the relationship between the proportion of effectively neutral mutations and local Neacross the genome. In conclusion, the predictions of the slightly deleterious model of molecular evolution hold well for species with small Ne. But for species with large Nethe fit is improved by incorporating linked positive selection to the model.
ΔN-Tp63 mediates Wnt/β-catenin-induced inhibition of differentiation in basal stem cells of mucociliary epithelia
Authors: Haas Maximilian , Vázquez José Luis Gómez , Sun Dingyuan Iris , Tran Hong Thi , Brislinger Magdalena , Tasca Alexia , Shomroni Orr , Vleminckx Kris , Walentek Peter
Published: June 2019

Mucociliary epithelia provide a first line of defense against pathogens in the airways and the epidermis of vertebrate larvae. Impaired regeneration and remodeling of mucociliary epithelia are associated with dysregulated Wnt/β-catenin signaling in chronic airway diseases, but underlying mechanisms remain elusive and studies of Wnt signaling in mucociliary cells yield seemingly contradicting results. Employing theXenopusmucociliary epidermis, the mouse airway, and human airway basal stem cell cultures, we characterize the evolutionarily conserved roles of Wnt/β-catenin signaling in mucociliary cells in vertebrates. Wnt signaling is required in multiciliated cells for cilia formation during differentiation stages, but in Basal cells, Wnt signaling prevents specification and differentiation of epithelial cell types by activatingΔN-TP63expression. We demonstrate that ΔN-TP63 is a master transcription factor in Basal cells, which is necessary and sufficient to mediate the Wnt-induced inhibition of differentiation and is required to retain basal stem cells during development. Chronic stimulation of Wnt signaling leads to mucociliary remodeling and Basal cell hyperplasia, but this is reversiblein vivoandin vitro, suggesting Wnt inhibition as an option in the treatment of chronic lung diseases. Our work sheds light into the evolutionarily conserved regulation of stem cells and differentiation, resolves Wnt functions in mucociliary epithelia, and provides crucial insights into mucociliary development, regeneration and disease mechanisms.
Oligomerization of NLR immune receptor RPP7 triggered by atypical resistance protein RPW8/HR as ligand
Authors: Li Lei , Habring Anette , Wang Kai , Weigel Detlef
Published: June 2019

In certain plant hybrids, autoimmunity is triggered by immune components that interact in the absence of a pathogen trigger. Often, NLR immune receptors are involved, with a particularly interesting case inArabidopsis thalianainvolving variants of the NLR RPP7 as well as variants of RPW8/HR proteins, which are homologs of animal MLKL and fungal HELL domain proteins. We demonstrate that HR4Fei-0but not the closely related HR4Col-0protein directly disrupts intramolecular association of RPP7bLerik1-3, which in turn initiates P-loop dependent NLR signaling. In agreement, RPP7bLerik1-3forms a higher-order complex only in the presence of HR4Fei-0but not HR4Col-0. In addition, we find that HR4Fei-0on its own can form detergent-resistant oligomers suggestive of amyloid-like aggregates, which in turn can directly kill cells in an RPP7bLerik1-3-independent manner. Our work provides in vivo biochemical evidence for a plant resistosome complex and the mechanisms by which RPW8/HR proteins trigger cell death.
Cardiac myocytes respond differentially and synergistically to matrix stiffness and topography
Authors: Wan William , Bjorkman Kristen K. , Choi Esther S. , Panepento Amanda L. , Anseth Kristi S. , Leinwand Leslie A.
Published: June 2019

During cardiac disease progression, myocytes undergo molecular, functional and structural changes, including increases in cell size and shape, decreased myocyte alignment and contractility. The heart often increases extracellular matrix production and stiffness, which affect myocytes. The order and hierarchy of these events remain unclear as available in vitro cell culture systems do not adequately model both physiologic and pathologic environments. Traditional cell culture substrates are 5-6 orders of magnitude stiffer than even diseased native cardiac tissue. Studies that do account for substrate stiffness often do not consider intercellular alignment and vice versa. We developed a cardiac myocyte culture platform that better recapitulates native tissue stiffness while simultaneously introducing topographical cues that promote cellular alignment. We show that stiffness and topography impact myocyte molecular and functional properties. We used a spatiotemporally-tunable, photolabile hydrogel platform to generate a range of stiffness and micron-scale topographical patterns to guide neonatal rat ventricular myocyte morphology. Importantly, these substrate patterns were of subcellular dimensions to test whether cells would spontaneously respond to topographical cues rather than an imposed geometry. Cellular contractility was highest and the gene expression profile was most physiologic on gels with healthy cardiac tissue stiffness. Surprisingly, while elongated patterns in stiff gels yielded the greatest cellular alignment, the cells actually had more pathologic functional and molecular profiles. These results highlight that morphological measurements alone are not a surrogate for overall cellular health as many studies assume. In general, substrate stiffness and micropatterning synergistically affect cardiac myocyte phenotype to recreate physiologic and pathologic microenvironments.

Significance Statement

Heart disease is accompanied by organ- and cellular-level remodeling, and deconvoluting their interplay is complex. Cellular-level change is best studied in vitro due to greater control and uniformity of cell types compared to animals. One common metric is degree of cellular alignment as misalignment of myocytes is a hallmark of disease. However, most studies utilize featureless culture surfaces that are orders of magnitude stiffer than, and do not mimic the scaffolding of, the heart. We developed a hydrogel platform with tunable stiffness and patterns providing topographical alignment cues. We cultured heart cells on and characterized multifactorial responses to these dynamic surfaces. Interestingly, conditions that yielded greatest alignment did not yield the healthiest functional and molecular state. Thus, morphology alone is not an indicator of overall cellular health.
Coevolutive, Evolutive and Stochastic Information in Protein-Protein Interactions
Authors: Andrade Miguel , Pontes Camila , Treptow Werner
Published: June 2019

Here, we investigate the contributions of coevolutive, evolutive and stochastic information in determining protein-protein interactions (PPIs) based on primary sequences of two interacting protein families A and B. Specifically, under the assumption that coevolutive information is imprinted on the interacting amino acids of two proteins in contrast to other (evolutive and stochastic) sources spread over their sequences, we dissect those contributions in terms of compensatory mutations at physically-coupled and uncoupled amino acids of A and B. We find that physically-coupled amino-acids at short range distances store the largest per-contact mutual information content, with a significant fraction of that content resulting from coevolutive sources alone. The information stored in coupled amino acids is shown further to discriminate multi-sequence alignments (MSAs) with the largest expectation fraction of PPI matches – a conclusion that holds against various definitions of intermolecular contacts and binding modes. When compared to the informational content resulting from evolution at long-range interactions, the mutual information in physically-coupled amino-acids is the strongest signal to distinguish PPIs derived from cospeciation and likely, the unique indication in case of molecular coevolution in independent genomes as the evolutive information must vanish for uncorrelated proteins.

SIGNIFICANCE

The problem of predicting protein-protein interactions (PPIs) based on multi-sequence alignments (MSAs) appears not completely resolved to date. In previous studies, one or more sources of information were taken into account not clarifying the isolated contributions of coevolutive, evolutive and stochastic information in resolving the problem. By benefiting from data sets made available in the sequence- and structure-rich era, we revisit the field to show that physically-coupled amino-acids of proteins store the largest (per contact) information content to discriminate MSAs with the largest expectation fraction of PPI matches – a result that should guide new developments in the field, aiming at characterizing protein interactions in general.
Structural characterization of Treponema pallidum Tp0225 reveals an unexpected leucine-rich repeat architecture
Authors: Ramaswamy Raghavendran , Houston Simon , Loveless Bianca , Cameron Caroline E. , Boulanger Martin J.
Published: June 2019

The phylogenetically divergent spirochete bacterium Treponema pallidum subsp. pallidum is the causative agent of syphilis. Central to the capacity of T. pallidum to establish infection is the ability of the pathogen to attach to a diversity of host cells. Many pathogenic bacteria employ leucine-rich repeat (LRR) domain-containing proteins to mediate protein–protein interactions, including attachment to host components and establishment of infection. Intriguingly, T. pallidum expresses only one putative LRR domain-containing protein (Tp0225) with an unknown function. In an effort to ascribe a function to Tp0225, a comprehensive phylogenetic analysis was first performed; this investigation revealed that Tp0225 clusters with the pathogenic clade of treponemes. Its crystal structure was then determined to 2.0 Å resolution using Pt SAD phasing, which revealed a noncanonical architecture containing a hexameric LRR core with a discontinuous β-sheet bridged by solvent molecules. Furthermore, a surface-exposed, hydrophobic pocket, which was found in Tp0225 but is largely absent in canonical LRR domains from other pathogenic bacteria, may serve to coordinate a hydrophobic ligand. Overall, this study provides the first structural characterization of the sole LRR domain-containing protein from T. pallidum and offers insight into the unique molecular landscape of this important human pathogen.
Theoretical study of the properties of X-ray diffraction moiré fringes. I. Corrigenda and addenda
Authors: Yoshimura Jun-ichi
Published: June 2019

Seven corrections are made and several supplementary equations are added to the article by Yoshimura [Acta Cryst. (2015), A71, 368–381].
Combination modeling of auto body assembly dimension propagation considering multi-source information for variation reduction
Authors: Liu Yinhua , Zhang Shiming , Chu Guoping
Published: June 2019

Purpose

This paper aims to present a combination modeling method using multi-source information in the process to improve the accuracy of the dimension propagation relationship for assembly variation reduction.

Design/methodology/approach

Based on a variable weight combination prediction method, the combination model that takes the mechanism model and data-driven model based on inspection data into consideration is established. Furthermore, the combination model is applied to qualification rate prediction for process alarming based on the Monte Carlo simulation and also used in engineering tolerance confirmation in mass production stage.

Findings

The combination model of variable weights considers both the static theoretical mechanic variation propagation model and the dynamic variation relationships from the regression model based on data collections, and provides more accurate assembly deviation predictions for process alarming.

Originality/value

A combination modeling method could be used to provide more accurate variation predictions and new engineering tolerance design procedures for the assembly process.
Characterisation and jelly processing potential of different fig cultivars
Authors: Curi Paula Nogueira , Albergaria Francielly Corrêa , Pio Rafael , Schiassi Maria Cecília Evangelista Vasconcelos , Tavares Bruna de Sousa , Souza Vanessa Rios de
Published: June 2019

Purpose

The purpose of this paper is to characterise eight different fig cultivars with respect to antioxidant activity and bioactive compound content and to assess the influence of these cultivars on the physicochemical characteristics, rheological properties and sensory acceptance of the obtained jelly to identify cultivars with increased potential for processing when grown in subtropical regions.

Design/methodology/approach

The analyses of fig fruits and fig jellies were performed in triplicate. To characterise the fig cultivars, analyses of antioxidant activity, phenolic compound content and ascorbic acid concentration were performed on fresh fruits. For the jellies, the total titratable acidity, pH, soluble solids, colour, texture profile and sensory attributes were analysed.

Findings

With respect to antioxidant activity and bioactive compounds, the Roxo de Valinhos displayed the highest antioxidant activity according to the ABTS method, ß-carotene and DPPH; the Três num Prato, Lemon and Brunswick cultivars presented the highest ascorbic acid values; and the Três num Prato cultivar also had the highest total phenolic content. Generally, the various fig cultivars yielded jellies with different physical and chemical characteristics and different rheological properties. This variation did not significantly affect acceptability. This study demonstrates that all of the evaluated cultivars have high potential for processing.

Originality/value

This study evaluated the processing potential of Roxo de Valinhos and other fig cultivars in the form of jelly, which in view of the food risk concerns of the dried fig, seems to be an interesting alternative for consumption of processed fig.
Impact of outward FDI on firms’ productivity over the food industry: evidence from China
Authors: Chen Ting-gui , Lin Gan , Yabe Mitsuyasu
Published: June 2019

Purpose

The purpose of this paper is to study the impact of outward foreign direct investment (OFDI) on the productivity of parent firms over the food industry.

Design/methodology/approach

The main data in this paper are derived from the China Industrial Enterprise Database 2005–2013 and a data set of Chinese firms’ OFDI information. Then this paper uses propensity score matching to match the treatment and control groups with firm characteristics and combines that with the differences-in-differences method to estimate the real effect of OFDI on total factor productivity.

Findings

The food firm’s OFDI significantly improves the parent firm’s productivity (known as the OFDI own-firm effect), but this promotion only exists in the short term. The OFDI own-firm effect of food firms differs remarkably as the sub-sectors, regions and ownership of firms vary. The food firm’s OFDI in “non-tax havens” and high-income destinations has a significantly stronger effect on the parent firm’s productivity. FDI, R&D and exporting can effectively strengthen the OFDI own-firm effect of food firms.

Originality/value

The effect of OFDI on food industry productivity has not been researched yet. This paper aims to fill this gap. This paper further divides the characteristics of food firms into different sub-sectors, regions and ownership types for a comparative analysis, with the aim of conducting a more comprehensive study at the micro-level of firms. In addition, an investigation into which factors influence the degree of the OFDI own-firm effect at the micro-level has not been found in the literature. This paper will draw its own conclusions.
Corporate governance and payout policy: evidence from India
Authors: Rajput Monika , Jhunjhunwala Shital
Published: June 2019

Purpose

The purpose of this paper is to study the impact of ownership structure and corporate governance on dividend policy in emerging markets, like India. The study also analyses the moderation effects of board independence between ownership and dividend payout.

Design/methodology/approach

The data set of 1,546 Indian firms over the period of 2006-2017 has been used in this study. Tobit and logistic regression methods has been used. The data used in this study are collected from the Centre for Monitoring Indian Economy (CMIE) Prowess database. The sample firms are listed on Bombay Stock Exchange (BSE) and National Stock Exchange (NSE).

Findings

First, the study finds a significant positive influence of corporate governance on the decision to pay dividend and is an important determinant of the payout decision. Second, the study finds a significant negative relationship of family ownership with dividend payout decisions which indicates that family firms pay lower dividend. Finally, the result from the interaction effect of board independence with family ownership has significant positive influence on dividend policy.

Originality/value

This is one of the first attempt to show that there is an interaction between independent board and ownership structure. It shows that more independent and non-executive directors in the board of family controlled firms are likely to pay more dividends.
Approximation of complex organic tissue for investigation of the electromagnetic impact
Authors: Frivaldsky Michal , Pavelek Miroslav , Spanik Pavol , Faktorova Dagmar , Spanikova Gabriela
Published: June 2019

Purpose

The purpose of this paper is to study the performance of the approximated model of biological tissue for development of complex 3 D models. The comparison of results from the complex model of liver tissue and results from the approximated model is provided to validate the proposed approximation method.

Design/methodology/approach

The proposed model of hepatic tissue (respecting its heterogeneous character up to the microstructure of hepatic lobules) is used for analysis of current field distribution within this tissue. Initially, the complex model of tissue structure (respecting the heterogenous structure) is presented, considering its complicated structure. Consequently, the procedure for the approximation of a complex model is being described. The main motivation is the need for simple, fast and accurate simulation model, which can be consequently used within more complex modeling of human organs for investigation of negative impacts of electrosurgical equipment on heterogenic tissue structure. For these purposes, the complex and approximated model are mutually compared and evaluated.

Findings

The obtained results are exploitable for the analysis of the probability of injury formation in sensitive tissue structures, and the approximated model shall serve for optimization of complex and time-consuming analyses.

Research limitations/implications

Research limitations include development of precise and fast electro-magnetic simulation model of biological tissue.

Practical implications

Practical implications is focused on the optimization processes of the electro-surgical procedures.

Originality/value

The originality of the paper concerns the approximation method of organic tissue modeling.
An incremental learning approach for the text categorization using hybrid optimization
Authors: Kayest Mamta , Jain Sanjay Kumar
Published: June 2019

Purpose

Document retrieval has become a hot research topic over the past few years, and has been paid more attention in browsing and synthesizing information from different documents. The purpose of this paper is to develop an effective document retrieval method, which focuses on reducing the time needed for the navigator to evoke the whole document based on contents, themes and concepts of documents.

Design/methodology/approach

This paper introduces an incremental learning approach for text categorization using Monarch Butterfly optimization–FireFly optimization based Neural Network (MB–FF based NN). Initially, the feature extraction is carried out on the pre-processed data using Term Frequency–Inverse Document Frequency (TF–IDF) and holoentropy to find the keywords of the document. Then, cluster-based indexing is performed using MB–FF algorithm, and finally, by matching process with the modified Bhattacharya distance measure, the document retrieval is done. In MB–FF based NN, the weights in the NN are chosen using MB–FF algorithm.

Findings

The effectiveness of the proposed MB–FF based NN is proven with an improved precision value of 0.8769, recall value of 0.7957,F-measure of 0.8143 and accuracy of 0.7815, respectively.

Originality/value

The experimental results show that the proposed MB–FF based NN is useful to companies, which have a large workforce across the country.
Enabling and leveraging ambidexterity: influence of strategic orientations and knowledge stock
Authors: Ramachandran Indu , Lengnick-Hall Cynthia A. , Badrinarayanan Vishag
Published: June 2019

Purpose

This paper aims to develop and empirically test a framework articulating the effects of strategic orientations (entrepreneurial orientation and market orientation) on leveraging ambidexterity. Further, the paper examines the moderating effects of knowledge stock (market knowledge and technological knowledge) on the relationship between ambidexterity and firm performance to gain additional insights into how ambidexterity can be leveraged in an organization.

Design/methodology/approach

Data were obtained from CEOs (or equivalent members of the top management team) of 234 firms. The adequacy and psychometric properties of all measures were evaluated and purified using a maximum likelihood confirmatory factor analysis (CFA), and the hypotheses were tested using ordinary least squares (OLS). A number of post hoc tests were conducted to develop a nuanced understanding of proposed effects.

Findings

While both strategic orientations enhance an organization’s ability to be ambidextrous, results show that some types of knowledge stocks facilitate, whereas other types hinder the influence of ambidexterity on firm performance.

Research limitations/implications

Both strategic orientations enable ambidexterity; however, technological knowledge stock impedes the effect of ambidexterity on firm performance, while market knowledge stock enhances this relation. Cross-sectional nature of the study imposes limitations on causal inferences.

Practical implications

Different strategic orientations provide organizations with a cluster of knowledge acquisition and utilization capabilities that enable ambidexterity. However, organizations should be wary of indiscriminate accumulation of knowledge stocks – while certain types enhance the effect of ambidexterity, others may create competency traps or core rigidities and inhibit the effect of ambidexterity.

Originality/value

This study integrates related, yet hitherto fragmented, research streams to demonstrate the interconnectedness between strategic orientations, ambidexterity and existing knowledge stock. Several theoretical and managerial implications are identified.
A whole-school approach to supporting children and young people’s mental health
Authors: Glazzard Jonathan
Published: June 2019

Purpose

Supporting the mental health of children and young people is a global priority. The issue is not specific to England. However, evidence suggests that one in ten children and young people in England has a mental health need. This represents approximately three students in every classroom. The purpose of this paper is to highlight the role of schools in supporting children and young people’s mental health. Whilst the paper acknowledges that teachers are not trained health professionals, it is argued that a whole-school approach to mental health can support individuals in schools to remain mentally healthy. The elements of a whole-school approach are identified and discussed and some of the challenges in relation to implementation are considered. Critical to the development of a whole-school approach is the commitment from the school leadership team to promoting student and staff wellbeing.

Design/methodology/approach

This is a policy paper not an empirical study.

Findings

This paper has outlined the policy context in the UK in relation to children and young people’s mental health. It has addressed the risk and protective factors which can cause or mitigate against mental ill health and it has outlined the elements of a whole-school approach to mental health.

Originality/value

This paper explores the contribution that schools can make to supporting students’ mental health. There is limited research which addresses mental health in young people from a non-therapeutic angle.
Motivation to use big data and big data analytics in external auditing
Authors: Dagilienė Lina , Klovienė Lina
Published: June 2019

Purpose

This paper aims to explore organisational intentions to use Big Data and Big Data Analytics (BDA) in external auditing. This study conceptualises different contingent motivating factors based on prior literature and the views of auditors, business clients and regulators regarding the external auditing practices and BDA.

Design/methodology/approach

Using the contingency theory approach, a literature review and 21 in-depth interviews with three different types of respondents, the authors explore factors motivating the use of BDA in external auditing.

Findings

The study presents a few key findings regarding the use of BD and BDA in external auditing. By disclosing a comprehensive view of current practices, the authors identify two groups of motivating factors (company-related and institutional) and the circumstances in which to use BDA, which will lead to the desired outcomes of audit companies. In addition, the authors emphasise the relationship of audit companies, business clients and regulators. The research indicates a trend whereby external auditors are likely to focus on the procedures not only to satisfy regulatory requirements but also to provide more value for business clients; hence, BDA may be one of the solutions.

Research limitations/implications

The conclusions of this study are based on interview data collected from 21 participants. There is a limited number of large companies in Lithuania that are open to co-operation. Future studies may investigate the issues addressed in this study further by using different research sites and a broader range of data.

Practical implications

Current practices and outcomes of using BD and BDA by different types of respondents differ significantly. The authors wish to emphasise the need for audit companies to implement a BD-driven approach and to customise their audit strategy to gain long-term efficiency. Furthermore, the most challenging factors for using BDA emerged, namely, long-term audit agreements and the business clients’ sizes, structures and information systems.

Originality/value

The original contribution of this study lies in the empirical investigation of the comprehensive state-of-the-art of BDA usage and motivating factors in external auditing. Moreover, the study examines the phenomenon of BD as one of the most recent and praised developments in the external auditing context. Finally, a contingency-based theoretical framework has been proposed. In addition, the research also makes a methodological contribution by using the approach of constructivist grounded theory for the analysis of qualitative data.
Non-audit fees and auditor independence: Nigerian evidence
Authors: Onulaka Paul Nnamdi , Shubita Moade Fawzi , Combs Alan
Published: June 2019

Purpose

This study aims to investigate the extent to which the provision of non-audit services (NAS) by external auditors to audit clients affects auditors’ independence and the audit expectation gap in Nigeria.

Design/methodology/approach

The study adopts an interpretivist approach. In total, 30 semi-structured, face-to-face interviews were conducted to explore the views expressed by audit partners and pension fund managers in Nigeria; group responses were evaluated and presented separately. After transcribing the interview audio recordings, a thematic data analysis of the two groups’ responses was performed.

Findings

Interpretation of the interview responses indicates that the provision of NAS by audit firms to their audit clients is regarded by auditors as a matter of economic necessity. Nevertheless, it is also perceived as impeding auditors’ independence and increasing the gap between the auditor and public expectations.

Practical implications

This study contributes to the debate surrounding the need for an independent body to oversee auditing standard setting distinct from the current practice to enhance transparency.

Originality/value

A qualitative analysis of the nuanced responses obtained from the semi-structured interviews reveals starkly the perceived economic pressures on auditors to accept non-audit work. Moreover, it endorses the regulation to restrict non-audit work in support of a sustainable fee level for an independent audit.
Islamic hedging for pilgrimage funds: case of Indonesia
Authors: Ismal Rifki , Septiana Nurul Izzati
Published: June 2019

Purpose

The demand for Saudi Arabian real (SAR) is very high in the pilgrimage (hajj) season while the authority, unfortunately, does not hedge the hajj funds. As such, the hajj funds are potentially exposed to exchange rate risk, which can impact the value of hajj funds and generate extra cost to the pilgrims. The purpose of this paper is to conduct simulations of Islamic hedging for pilgrimage funds to: mitigate and minimize exchange rate risk, identify and recommend the ideal time, amount and tenors of Islamic hedging for hajj funds, estimate cost saving by pursuing Islamic hedging and propose technical and general recommendations for the authority.

Design/methodology/approach

Forward transaction mechanism is adopted to compute Islamic forward between SAR and Rupiah (Indonesian currency) or IDR. Findings – based on simulations, the paper finds that: the longer the Islamic hedging tenors, the better is the result of Islamic hedging, the decreasing of IDR/USD is the right time to hedge the hajj funds and, on the other hand, the IDR/SAR appreciation is not the right time to hedge the hajj funds.

Findings

Based on simulations, the paper finds that: the longer the Islamic hedging tenors, the better is the result of Islamic hedging, the decreasing of IDR/USD is the right time to hedge the hajj funds and, on the other hand, the IDR/SAR appreciation is not the right time to hedge the hajj funds.

Research limitations/implications

The research suggests the authority to (and not to) hedge the hajj fund, depending on economic conditions and market indicators. Even though the assessment is for the Indonesian case, other countries maintaining hajj funds might also learn from this paper.

Originality/value

To the best of author’s knowledge, this is the first paper in Indonesia that attempts to simulate the optimal hedging of hajj funds.