bluuebunny/crossref_metadata_2025 huggingface dataset:
Fusion proteins towards fungi and bacteria in plant protection
Authors: Pinheiro Ana Margarida , Carreira Alexandra , Ferreira Ricardo B. , Monteiro Sara
Published: December 2017

In agriculture, although fungi are considered the foremost problem, infections by bacteria also cause significant economical losses. The presence of different diseases in crops often leads to a misuse of the proper therapeutic, or the combination of different diseases forces the use of more than one pesticide. This work concerns the development of a ‘super-Blad’: a chimeric protein consisting of Blad polypeptide, the active ingredient of a biological fungicide already on the market, and two selected peptides, SP10-5 and Sub5, proven to possess biological potential as antibacterial agents. The resulting chimeric protein obtained from the fusion of Blad with SP10-5 not only maintained strong antibacterial activity, especially against Xanthomonas spp. and Pseudomonas syringae, but was also able to retain the ability to inhibit the growth of both yeast and filamentous fungi. However, the antibacterial activity of Sub5 was considerably diminished when fused with Blad, which seems to indicate that not all fusion proteins behave equally. These newly designed drugs can be considered promising compounds for use in plant protection. A deeper and focused development of an appropriate formulation may result in a potent biopesticide that can replace, per se, two conventional chemistries with less impact on the environment.
OCR-Stats: Robust estimation and statistical testing of mitochondrial respiration activities using Seahorse XF Analyzer
Authors: Yépez Vicente A. , Kremer Laura S. , Iuso Arcangela , Gušić Mirjana , Kopajtich Robert , Koňaříková Eliška , Nadel Agnieszka , Wachutka Leonhard , Prokisch Holger , Gagneur Julien
Published: December 2017

Accurate quantification of cellular and mitochondrial bioenergetic activity is of great interest in medicine and biology. Mitochondrial stress tests performed with Seahorse Bioscience XF Analyzers allow estimating different bioenergetic measures by monitoring oxygen consumption rates (OCR) of living cells in multi-well plates. However, studies of statistical best practices for determining OCR measurements and comparisons have been lacking so far. Therefore, we performed mitochondrial stress tests in 126 96-well plates involving 203 fibroblast cell lines to understand how OCR behaves across different biosamples, wells, and plates. We show that the noise of OCR is multiplicative, that outlier data points can concern individual measurements or all measurements of a well, and that the inter-plate variation is greater than intra-plate variation. Based on these insights, we developed a novel statistical method, OCR-Stats, that: i) robustly estimates OCR levels modeling multiplicative noise and automatically identifying outlier data points and outlier wells; and ii) performs statistical testing between samples, taking into account the different magnitudes of the between- and within-plates variations. This led to a significant reduction of the coefficient of variation across plates of basal respiration by 36% and of maximal respiration by 32%. Moreover, using positive and negative controls, we show that our statistical test outperforms existing methods, which either suffer from an excess of false positives (within-plates methods), or of false negatives (between-plates methods). Altogether, the aim of this study is to propose statistical good practices to support experimentalists in designing, analyzing, testing and reporting results of mitochondrial stress tests using this high throughput platform.
Three-dimensional cultured Liver-on-a-Chip with mature hepatocyte-like cells derived from human pluripotent stem cells
Authors: Kamei Ken-ichiro , Yoshioka Momoko , Terada Shiho , Tokunaga Yumie , Chen Yong
Published: December 2017

Liver-on-a-Chip technology holds considerable potential for applications in drug screening and chemical-safety testing. To establish such platforms, functional hepatocytes are required; however, primary hepatocytes are commonly used, despite problems involving donor limitations, lot-to-lot variation, and unsatisfactory two-dimensional culture methods. Although human pluripotent stem cells (hPSCs) may represent a strong alternative contender to address the aforementioned issues, remaining technological challenges include the robust, highly efficient production of high-purity hepatic clusters. In addition, current Liver-on-a-Chip platforms are relatively complicated and not applicable for high-throughput experiments. Here, we develop a very simple Liver-on-a-Chip platform with mature and functional hepatocyte-like cells derived from hPSCs. To establish a method for hepatic differentiation of hPSCs, cells were first treated by inhibiting the phosphoinositide 3-kinase- and Rho-associated protein kinase-signaling pathways to stop self-renewal and improve survival, respectively, which enabled the formation of a well-defined endoderm and facilitated hepatocyte commitment. Next, a simple microfluidic device was used to create a three-dimensional (3D) culture environment that enhanced the maturation and function of hepatocyte-like cells by increasing the expression of both hepatic maturation markers and cytochrome P450. Finally, we confirmed improvements in hepatic functions, such as drug uptake/excretion capabilities, in >90% of 3D-matured hepatocyte-like cells by indocyanin green assay. These results indicated that the incorporation of hPSC-derived hepatocytes on our Liver-on-a-Chip platform may serve to enhance the processes involved in drug screening and chemical-safety testing.
Modeling Systemic Colorimetric Parameters as a Tool for Processing Images of Clumps of Toxic Cyanobacteria Targeted at Their Boundaries Detection
Authors: Bespalov Yu. G. , Nosov K. V. , Kabalyants P. S.
Published: December 2017

Global climate change, along with other large-scale consequences of human impact upon the nature, increases the risk of biosafety threats associated with the disturbance of stability of communities of living organisms. In this regard, the topicality of the challenge of developing methods for monitoring and correcting homeostasis mechanisms that can support this stability is a problem of premium importance.

The work aims at investigation of techniques of remote detection of toxic cyanobacteria clumps in water area, with the use of dynamical modeling.
Shape-related characteristics of age-related differences in subcortical structures
Authors: Madan Christopher R.
Published: December 2017

OBJECTIVES

With an increasing aging population, it is important to gain a better understanding of biological markers of aging. Subcortical volume is known to differ with age; additionally considering shape-related characteristics may provide a better index of age-related differences in subcortical structure. Recently fractal dimensionality has been shown to be more sensitive to age-related differences, but this measure is borne out of mathematical principles, rather than quantifying a neurobiologically relevant characteristic directly. We considered four distinct measures of shape and how they relate to aging and fractal dimensionality: surface-to-volume ratio, sphericity, long-axis curvature, and surface texture.

METHODS

Structural MRIs from two samples, with a combined sample size of over 600 healthy adults across the adult lifespan, were used to measure age-related differences in the structure of the thalamus, putamen, caudate, and hippocampus. For each structure, volume and fractal dimensionality were calculated, as well as each of the four distinct shape measures. These measures were then examined in their utility in explaining age-related variability in brain structure.

RESULTS

The four shape measures were able to account for 80-90% of the variance in fractal dimensionality, indicating that these measures were sensitive to the same shape characteristics. Of the distinct shape measures, surface-to-volume ratio was the most sensitive aging biomarker.

CONCLUSION

Though volume is often used to characterize inter-individual differences in subcortical structures, our results demonstrate that additional measures can be useful complements to volumetry. Our results indicate that shape characteristics of subcortical structures are useful biological markers of healthy aging.
Estimating the functional dimensionality of neural representations
Authors: Ahlheim Christiane , Love Bradley C.
Published: December 2017

Recent advances in multivariate fMRI analysis stress the importance of information inherent to voxel patterns. Key to interpreting these patterns is estimating the underlying dimensionality of neural representations. Dimensions may correspond to psychological dimensions, such as length and orientation, or involve other coding schemes. Unfortunately, the noise structure of fMRI data inflates dimensionality estimates and thus makes it difficult to assess the true underlying dimensionality of a pattern. To address this challenge, we developed a novel approach to identify brain regions that carry reliable task-modulated signal and to derive an estimate of the signal’s functional dimensionality. We combined singular value decomposition with cross-validation to find the best low-dimensional projection of a pattern of voxel-responses at a single-subject level. Goodness of the low-dimensional reconstruction is measured as Pearson correlation with a test set, which allows to test for significance of the low-dimensional reconstruction across participants. Using hierarchical Bayesian modeling, we derive the best estimate and associated uncertainty of underlying dimensionality across participants. We validated our method on simulated data of varying underlying dimensionality, showing that recovered dimensionalities match closely true dimensionalities. We then applied our method to three published fMRI data sets all involving processing of visual stimuli. The results highlight three possible applications of estimating the functional dimensionality of neural data. Firstly, it can aid evaluation of model-based analyses by revealing which areas express reliable, task-modulated signal that could be missed by specific models. Secondly, it can reveal functional differences across brain regions. Thirdly, knowing the functional dimensionality allows assessing task-related differences in the complexity of neural patterns.
Similar clinical improvement and maintenance after rTMS at 5 Hz using a simple vs. complex protocol in Alzheimer’s disease
Authors: Alcalá-Lozano R. , Morelos-Santana E. , Cortés-Sotres J.F. , Garza-Villarreal E. A. , Sosa-Ortiz A. L. , Gonzalez-Olvera J. J.
Published: December 2017

Brackground

Current treatments for Alzheimer’s disease (AD) have a limited clinical response and methods, such as repetitive transcranial magnetic stimulation (rTMS), are being studied as possible treatments for the clinical symptoms with positive results. However, there is still seldom information on the type of rTMS protocols that deliver the best clinical improvement in AD.

Objetive

To compare the clinical response between a simple stimulation protocol on the left dorsolateral prefrontal cortex (lDLPFC) against a complex protocol using six regions of interest.

Methods

19 participants were randomized to receive any of the protocols. The analysis of repeated measures evaluated the change.

Results

Both protocols were equally proficient at improving cognitive function, behavior and functionality after 3 weeks of treatment, and the effects were maintained for 4 weeks more without treatment.

Conclusion

We suggest rTMS on the lDLPFC could be enough to provide a clinical response, and the underlying mechanisms should be studied.
Phasic Activation of Ventral Tegmental, but not Substantia Nigra, Dopamine Neurons Promotes Model-Based Pavlovian Reward Learning
Authors: Keiflin R. , Pribut H.J. , Shah N.B. , Janak P.H.
Published: December 2017

Dopamine (DA) neurons in the ventral tegmental area (VTA) and substantia nigra (SNc) encode reward prediction errors (RPEs) and are proposed to mediate error-driven learning. However the learning strategy engaged by DA-RPEs remains controversial. Model-free associations imbue cue/actions with pure value, independently of representations of their associated outcome. In contrast, model-based associations support detailed representation of anticipated outcomes. Here we show that although both VTA and SNc DA neuron activation reinforces instrumental responding, only VTA DA neuron activation during consumption of expected sucrose reward restores error-driven learning and promotes formation of a new cue→sucrose association. Critically, expression of VTA DA-dependent Pavlovian associations is abolished following sucrose devaluation, a signature of model-based learning. These findings reveal that activation of VTA-or SNc-DA neurons engages largely dissociable learning processes with VTA-DA neurons capable of participating in model-based predictive learning, while the role of SNc-DA neurons appears limited to reinforcement of instrumental responses.
Derivation and validation of a VISITAG™-guided contact force ablation protocol for pulmonary vein isolation
Authors: Tomlinson David R.
Published: December 2017

Aims Following radiofrequency (RF) pulmonary vein isolation (PVI), atrial fibrillation (AF) recurrence mediated by recovery of pulmonary vein (PV) conduction is common. I examined whether comparative VISITAG™ (Biosense Webster Inc.) data analysis at sites showing intra-procedural recovery of PV conduction versus acutely durable ablation could inform the derivation of a more effective VISITAG™-guided contact force (CF) PVI protocol.

Methods and results Retrospective analysis of VISITAG™ Module annotated ablation site data in 10 consecutive patients undergoing CF-guided PVI without active VISITAG™ guidance. Employing 2mm positional stability range and lenient CF filter (force-over-time 10%, minimum 2g), inter-ablation site distance >10-12mm, adjacent 0g-minimum CF and short RF duration (3-5s) were associated with intra-procedural recovery of PV conduction. A VISITAG™-guided CF PVI protocol was derived employing ≤6mm inter-ablation site distances, minimum target ablation site duration ≥9s / force time integral (FTI) 100gs and 100% 1g-minimum CF filter. Seventy-two consecutive VISITAG™-guided CF PVI procedures were then undertaken using this protocol, with PVI achieved in all utilising 23.8[8.4] minutes total RF (30W, 48°C, 17ml/min, continuous RF application). Following protocol completion, acute intra-procedural spontaneous / dormant recovery of PV conduction requiring touch-up RF occurred in 1.4% / 1.8% of PVs, respectively. At 14[5] months’ follow-up in all 34 patients with paroxysmal AF ≥6 months’ post-ablation, 30 (88%) were free from atrial arrhythmia, off class I/III anti-arrhythmic medication.

Conclusion VISITAG™ provides means to identify and then avoid factors associated with intra-procedural recovery of PV conduction. This VISITAG™ Module-guided CF PVI protocol demonstrated excellent intra-procedural and long-term efficacy.

Condensed abstract Following CF-guided PVI, retrospective VISITAG™ Module analyses permitted the identification of ablation parameters associated with intra-procedural recovery of PV conduction. The derived VISITAG™ Module-guided CF PVI protocol employed short over RF duration yet proved efficient at achieving PVI acutely, with long-term follow-up demonstrating high clinical efficacy.
Application of the fluctuation theorem for non-invasive force measurement in living neuronal axons
Authors: Hayashi Kumiko , Tsuchizawa Yuta , Iwaki Mitsuhiro , Okada Yasushi
Published: December 2017

Although its importance is recently widely accepted, force measurement has been difficult in living biological systems, mainly due to the lack of the versatile non-invasive force measurement methods. The fluctuation theorem, which represents the thermodynamic properties of small fluctuating non-equilibrium systems, has been applied to the analysis of the thermodynamic properties of motor proteinsin vitro. Here, we extend it to the axonal transport (displacement) of endosomes. The distribution of the displacement fluctuation had three or four distinct peaks around multiples of a unit value, which the fluctuation theorem can convert into the drag force exerted on the endosomes. The results demonstrated that a single cargo vesicle is conveyed by one to three or four units of force production.
Exploring the Genetics of Lesion and Nodal Resistance in Pea (Pisum sativumL.) toSclerotinia sclerotiorumUsing Genome-wide Association Studies and RNA-Seq
Authors: Chang Hao-Xun , Sang Hyunkyu , Wang Jie , McPhee Kevin E. , Zhuang Xiaofeng , Porter Lyndon D. , Chilvers Martin I.
Published: December 2017

The disease white mold caused by the fungusSclerotinia sclerotiorumis a significant threat to pea production and improved resistance to this disease is needed. Nodal resistance in plants is a phenomenon where a fungal infection is prevented from passing through a node and the infection is limited to an internode region. Nodal resistance has been observed in some pathosystems such as the pea (Pisum sativumL.)-S. sclerotiorumpathosystem. Other than nodal resistance, different pea lines display different levels of stem lesion size restriction, referred to as lesion resistance. It is unclear whether the genetics of lesion resistance and nodal resistance are identical or different. This study applied genome-wide association studies (GWAS) and RNA-Seq to understand the genetic makeup of these two types of resistance. The time series RNA-Seq experiment consisted of two pea lines (the susceptible ‘Lifter’ and the partially resistant PI 240515), two treatments (mock samples andS. sclerotioruminoculated samples), and three time points (12, 24, and 48 hours post-inoculation). Integrated results from GWAS and RNA-Seq analyses identified different redox-related transcripts for lesion and nodal resistances. A transcript encoding a glutathione S-transferase was the only shared resistance source for both phenotypes. There were more leucine rich-repeat containing transcripts found for lesion resistance, while different candidate resistance transcripts such as a VQ motif-containing protein and a myo-inositol oxygenase were found for nodal resistance. This study demonstrated the robustness of combining GWAS and RNA-Seq for identifying white mold resistance in pea, and results suggest different genetics underlying lesion and nodal resistance.
Rapid adaptation in large populations with very rare sex: scalings and spontaneous oscillations
Authors: Pearce Michael T. , Fisher Daniel S.
Published: December 2017

Genetic exchange in microbes and other facultative sexuals can be rare enough that evolution is almost entirely asexual and populations almost clonal. But the benefits of genetic exchange depend crucially on the diversity of genotypes in a population. How very rare recombination together with the accumulation of new mutations shapes the diversity of large populations and gives rise to faster adaptation is still poorly understood. This paper analyzes a particularly simple model: organisms with two asexual chromosomes that can reassort during rare matings that occur at a rater. The speed of adaptation for large population sizes,N, is found to depend on the ratio ~ log(Nr)/log(N). For larger populations, the r needed to yield the same speed deceases as a power ofN. Remarkably, the population undergoes spontaneous oscillations alternating between phases when the fittest individuals are created by mutation and when they are created by reassortment, which—in contrast to conventional regimes—decreases the diversity. Between the two phases, the mean fitness jumps rapidly. The oscillatory dynamics and the strong fluctuations this induces have implications for the diversity and coalescent statistics. The results are potentially applicable to large microbial populations, especially viruses that have a small number of chromosomes. Some of the key features may be more broadly applicable for large populations with other types of rare genetic exchange.
Tissue architectural cues drive organ targeting of human tumor cells in zebrafish
Authors: Paul Colin D. , Bishop Kevin , Devine Alexus , Paine Elliott L. , Staunton Jack R. , Thomas Sarah M. , Jenkins Lisa M. Miller , Morgan Nicole Y. , Sood Raman , Tanner Kandice
Published: December 2017

Sites of metastasis are non-random, with certain types of cancers showing organ preference during distal colonization. Using multiple brain- and bone marrow-seeking human and murine breast cancer subclones, we determined that tumor cells that home to specific murine organs (brain and bone marrow) ultimately colonized analogous tissues (brain and caudal vein plexus [CVP]) in larval zebrafish. We then exploited the zebrafish model to delineate factors leading to differential cell homing and extravasation. Bone marrow-tropic clones showed higher expression of integrins and focal adhesions associated with mechanosensing machinery than brain-tropic clones and were more sensitive to vessel topography during extravasation. Knockdown of β1 integrin reduced extravasation and redistributed organ targeting from disordered vessels in the CVP to the brain. Our results show that organ selectivity is driven by topography- and cell type-dependent extravasation at the tumor-endothelial interface in the larval zebrafish and provide important insights into the early stages of metastasis.
Characterizing the response to face pareidolia in human category-selective visual cortex
Authors: Wardle Susan G , Seymour Kiley , Taubert Jessica
Published: December 2017

The neural mechanisms underlying face and object recognition are understood to originate in ventral occipital-temporal cortex. A key feature of the functional architecture of the visual ventral pathway is its category-selectivity, yet it is unclear how category-selective regions process ambiguous visual input which violates category boundaries. One example is the spontaneous misperception of faces in inanimate objects such as the Man in the Moon, in which an object belongs to more than one category and face perception is divorced from its usual diagnostic visual features. We used fMRI to investigate the representation of illusory faces in category-selective regions. The perception of illusory faces was decodable from activation patterns in the fusiform face area (FFA) and lateral occipital complex (LOC), but not from other visual areas. Further, activity in FFA was strongly modulated by the perception of illusory faces, such that even objects with vastly different visual features were represented similarly if all images contained an illusory face. The results show that the FFA is broadly-tuned for face detection, not finely-tuned to the homogenous visual properties that typically distinguish faces from other objects. A complete understanding of high-level vision will require explanation of the mechanisms underlying natural errors of face detection.
Haploinsufficiency of Parkinsonism Gene SYNJ1 Contributes to Dopamine neuron Vulnerability in Aged Mice
Authors: Pan Ping-Yue , Sheehan Patricia , Wang Qian , Zhang Yuanxi , Wang Jing , El Gaamouch Farida , Zhu Li , Cai Dongming , Yue Zhenyu
Published: December 2017

Parkinson’s disease (PD) is an age-dependent neurodegenerative disorder characterized by the loss of substantia nigra dopaminergic (DAergic) neurons in ventral midbrain (MB). Identification of interactions between aging and the known risk variants is crucial to understanding the etiology of PD. Recessive mutations in SYNJ1 have recently been linked to familial early-onset atypical Parkinsonism. We now show an age-dependent decline of SYNJ1 expression in the striatum as well as in striatal DAergic terminals of aged mice. Heterozygous deletion of SYNJ1 in mice causes selective elevation of PIP2 in the MB, and manipulation of PIP2 levels also impairs synaptic vesicle recycling preferentially in MB neurons. SYNJ1+/− mice display progressive PD-like behavioral alterations and DAergic terminal degeneration. Furthermore, we found down-regulation of human SYNJ1 transcripts in a subset of sporadic PD brains, corroborating the role of an age-dependent decrease in SYNJ1 in predisposing DAergic neuron vulnerability and PD pathogenesis.
The complement system supports normal postnatal development and gonadal function in both sexes
Authors: Lee Arthur S. , Rusch Jannette , Usmani Abul , Lima Ana C. , Wong Wendy S.W. , Huang Ni , Lepamets Maarja , Vigh-Conrad Katinka A. , Worthington Ronald E. , Mägi Reedik , Niederhuber John E. , Wu Xiaobo , Atkinson John P. , Hess Rex A. , Conrad Donald F.
Published: December 2017

Male and female infertility are clinically managed and classified as distinct diseases, and relatively little is known about mechanisms of gonadal function common to both sexes. We used genome-wide genetic analysis on 74,896 women and men to find rare genetic variants that modulate gonadal function in both sexes. This uncovered an association with variants disrupting CSMD1, a complement regulatory protein located on 8p23, in a genomic region with an exceptional evolution. We found that Csmd1 knockout mice display a diverse array of gonadal defects in both sexes, and in females, impaired mammary gland development that leads to increased offspring mortality. The complement pathway is significantly disrupted in Csmd1 mice, and further disruption of the complement pathway from joint inactivation of C3 leads to more extreme reproductive defects. Our results can explain a novel human genetic association with infertility and implicate the complement system in the normal development of postnatal tissues.
The genomic and ecological context of hybridization affect the probability that symmetrical incompatibilities drive hybrid speciation
Authors: Comeault Aaron A.
Published: December 2017

Despite examples of homoploid hybrid species, theoretical work describing when, where, and how we expect homoploid hybrid speciation to occur remains relatively rare. Here I explore the probability of homoploid hybrid speciation due to “symmetrical incompatibilities” under different selective and genetic scenarios. Through simulation, I test how genetic architecture and selection acting on traits that do not themselves generate incompatibilities interact to affect the probability that hybrids evolve symmetrical incompatibilities with their parent species. Unsurprisingly, selection against admixture at ‘adaptive’ loci that are linked to loci that generate incompatibilities tends to reduce the probability of evolving symmetrical incompatibilities. By contrast, selection that favors admixed genotypes at adaptive loci can promote the evolution of symmetrical incompatibilities. The magnitude of these outcomes is affected by the strength of selection, aspects of genetic architecture such as linkage relationships and the linear arrangement of loci along a chromosome, and the amount of hybridization following the formation of a hybrid zone. These results highlight how understanding the nature of selection, aspects of the genetics of traits affecting fitness, and the strength of reproductive isolation between hybridizing taxa can all be used to inform when we expect to observe homoploid hybrid speciation due to symmetrical incompatibilities.
netSmooth: Network-smoothing based imputation for single cell RNA-seq
Authors: Ronen Jonathan , Akalin Altuna
Published: December 2017

Single cell RNA-seq (scRNA-seq) experiments suffer from a range of characteristic technical biases, such as dropouts (zero or near zero counts) and high variance. Current analysis methods rely on imputing missing values by various means of local averaging or regression, often amplifying biases inherent in the data. We present netSmooth, a network-diffusion based method that uses priors for the covariance structure of gene expression profiles on scRNA-seq experiments in order to smooth expression values. We demonstrate that netSmooth improves clustering results of scRNA-seq experiments from distinct cell populations, time-course experiments, and cancer genomics. We provide an R package for our method, available at: https://github.com/BIMSBbioinfo/netSmooth.
Parental legacy, demography, and introgression influenced the evolution of the two subgenomes of the tetraploidCapsella bursa-pastoris(Brassicaceae)
Authors: Kryvokhyzha Dmytro , Salcedo Adriana , Eriksson Mimmi C. , Duan Tianlin , Tawari Nilesh , Chen Jun , Guerrina Maria , Kreiner Julia M. , Kent Tyler V. , Lagercrantz Ulf , Stinchcombe John R. , Glémin Sylvain , Wright Stephen I. , Lascoux Martin
Published: December 2017

Allopolyploidy is generally perceived as a major source of evolutionary novelties and as an instantaneous way to create isolation barriers. However, we do not have a clear understanding of how two subgenomes evolve and interact once they have fused in an allopolyploid species and how isolated they are from their relatives. Here, we address these questions by analyzing genomic and transcriptomic data of allotetraploidCapsella bursa-pastorisin three differentiated populations, Asia, Europe and the Middle East. We phased the two subgenomes, one descended from the outcrossing and highly diverseCapsella grandiflora(Cg) and the other one from the selfing and genetically depauperateCapsella orientalis(Co). For each subgenome, we assessed its relationship with the diploid relatives, temporal change of effective population sizeNe, signatures of positive and negative selection, and gene expression patterns. Introgression betweenC. bursa-pastorisand its diploid relatives was widespread and the two subgenomes were impacted differentially depending on geographic region. In all three regions, Ne of the two subgenomes decreased gradually and the Co subgenome accumulated more deleterious changes than Cg. Selective sweeps were more common on the Cg subgenome in Europe and the Middle East, and on the Co subgenome in Asia. In contrast, differences in expression were limited with the Cg subgenome slightly more expressed than Co in Europe and the Middle-East. In summary, after more than 100,000 generations of co-existence, the two subgenomes ofC. bursa-pastorisstill retained a strong signature of parental legacy and were differentially affected by introgression and selection.
Design and performance of the variable-wavelength Bonse–Hart ultra-small-angle neutron scattering diffractometer KOOKABURRA at ANSTO
Authors: Rehm Christine , de Campo Liliana , Brûlé Alain , Darmann Frank , Bartsch Friedl , Berry Andrew
Published: December 2017

The double-crystal ultra-small-angle neutron scattering (USANS) diffractometer KOOKABURRA at ANSTO was made available for user experiments in 2014. KOOKABURRA allows the characterization of microstructures covering length scales in the range of 0.1–10 µm. Use of the first- and second-order reflections coming off a doubly curved highly oriented mosaic pyrolytic graphite premonochromator at a fixed Bragg angle, in conjunction with two interchangeable pairs of Si(111) and Si(311) quintuple-reflection channel-cut crystals, permits operation of the instrument at two individual wavelengths, 4.74 and 2.37 Å. This unique feature among reactor-based USANS instruments allows optimal accommodation of a broad range of samples, both weakly and strongly scattering, in one sample setup. The versatility and capabilities of KOOKABURRA have already resulted in a number of research papers, clearly demonstrating that this instrument has a major impact in the field of large-scale structure determination.
Detection and estimation of mental fatigue in manual assembly process of complex products
Authors: Xiao Hong , Duan Yugang , Zhang Zhongbo , Li Ming
Published: December 2017

Purpose

This paper aims to investigate an approach for mental fatigue detection and estimation of assembly operators in the manual assembly process of complex products, with the purpose of founding the basis for adaptive transfer and demonstration of assembly process information (API), and eventually making the manual assembly process smarter and more human-friendly.

Design/methodology/approach

The proposed approach detects and estimates the mental state of assembly operators by electroencephalography (EEG) signal recording and analysis in an engine assembly experiment. When the subjects perform assembly tasks, their EEG signal is recorded by a portable EEG recording system called Emotiv EPOC+ headset. The feature set of the EEG signal is then extracted by calculating its power spectrum density (PSD), followed by data dimension reduction based on principal component analysis (PCA). The dimension-reduced data are classified by using support vector machines (SVMs), and hence, the mental state of assembly operators can be estimated during the assembly process.

Findings

The experimental result shows that the proposed approach is able to estimate the mental state of assembly operators within an acceptable accuracy range, and the PCA-based dimension reduction method performs very well by representing the high-dimensional EEG feature set with just a few principal components.

Originality/value

This paper provides theoretical and experimental basis for the API transfer and demonstration based on human cognition. It provides a new idea to seek balance between the improvement of production efficiency and the sustainable utilization of human resources.
Physical deformation configuration of a spatial clamped cable based on Kirchhoff rods
Authors: Du Hongwang , Xiong Wei , Wang Haitao , Wang Zuwen
Published: December 2017

Purpose

In this study, a modeling method for a clamped deformable cable simulation based on Kirchhoff theory is proposed. This methodology can be used to describe the physical deformation configuration of any constrained flexible cable in a computer-aided design/manufacturing system. The modeling method, solution algorithm, simulation and experimental results are presented to prove the feasibility of the proposed methodology. The paper aims to discuss these issues.

Design/methodology/approach

First, Kirchhoff equations for deformable cables are proposed based on the nonlinear mechanics of thin elastic rods, and the general solution of the equations described by the Euler angles is given in the arc coordinate system. The parametric form solution of the Kirchhoff equations, which is easy to use, is then obtained in a cylindrical coordinate form based on Saint Venant’s theory. Finally, mathematical expressions that reflect the clamped cable configuration are given, and the deformable process is simulated based on an open source geometry kernel and is then tested by a 3D laser scanning technology.

Findings

The method presented in this paper can be adapted to any boundary condition for constrained cables as long as the external force and torque are known. The experimental results indicate that both the model and algorithm are efficient and accurate.

Research limitations/implications

A more comprehensive study must be executed for the physical simulation of more complicated constrained cables, such as the helical spring and asymmetric constraint. The influence of the material properties of the cable on the calculation efficiency must be considered in future analysis.

Originality/value

The semi-analytical algorithm of the cable simulation in cylindrical coordinates is a novel topic and is more accurate and efficient than the common numerical solution.
Implementation of blockchain-based energy trading system
Authors: Oh Se-Chang , Kim Min-Soo , Park Yoon , Roh Gyu-Tak , Lee Chin-Woo
Published: December 2017

Purpose

The centralized processes of today’s power trading systems are complex and pose a risk of price tampering and hacking. The decentralized and unmodifiable nature of the blockchain technology that has recently been highlighted offers the potential to improve this power trading process. The purpose of this study is to implement a system to apply the blockchain technology to the problem of power trading.

Design/methodology/approach

The authors modeled the power trading problem as the interaction between admin, producer and consumer nodes. And a power trading scenario has been created for this model using a blockchain platform called Multichain which is both fast and highly scalable. To verify this scenario, they implemented a trading system using Savoir, a Python-based JsonRPC module.

Findings

Experimental results show that all processes, such as blockchain creation, node connectivity, asset issuance and exchange transactions have been correctly handled according to the scenario.

Originality/value

In this study, the authors have proposed and implemented a power trading method that determines price according to the pure market principle and cannot be manipulated or hacked. It is based on the nature of blockchain technology that is decentralized and cannot be tampered.
Climate impact assessment and “islandness”
Authors: Foley Aideen Maria
Published: December 2017

Purpose

Climate data, including historical climate observations and climate model outputs, are often used in climate impact assessments, to explore potential climate futures. However, characteristics often associated with “islandness”, such as smallness, land boundedness and isolation, may mean that climate impact assessment methods applied at broader scales cannot simply be downscaled to island settings. This paper aims to discuss information needs and the limitations of climate models and datasets in the context of small islands and explores how such challenges might be addressed.

Design/methodology/approach

Reviewing existing literature, this paper explores challenges of islandness in top-down, model-led climate impact assessment and bottom-up, vulnerability-led approaches. It examines how alternative forms of knowledge production can play a role in validating models and in guiding adaptation actions at the local level and highlights decision-making techniques that can support adaptation even when data is uncertain.

Findings

Small island topography is often too detailed for global or even regional climate models to resolve, but equally, local meteorological station data may be absent or uncertain, particularly in island peripheries. However, rather than viewing the issue as decision-making with big data at the regional/global scale versus with little or no data at the small island scale, a more productive discourse can emerge by conceptualising strategies of decision-making with unconventional types of data.

Originality/value

This paper provides a critical overview and synthesis of issues relating to climate models, data sets and impact assessment methods as they pertain to islands, which can benefit decision makers and other end-users of climate data in island communities.
Developing entrepreneurship in Africa: investigating critical resource challenges
Authors: Atiase Victor Yawo , Mahmood Samia , Wang Yong , Botchie David
Published: December 2017

Purpose

By drawing upon institutional theory, the purpose of this paper is to investigate the role of four critical resources (credit, electricity, contract enforcement and political governance) in explaining the quality of entrepreneurship and the depth of the supporting entrepreneurship ecosystem in Africa.

Design/methodology/approach

A quantitative approach based on ordinary least squares regression analysis was used. Three data sources were employed. First, the Global Entrepreneurship Index (GEI) of 35 African countries was used to measure the quality of entrepreneurship and the depth of the entrepreneurial ecosystem in Africa which represents the dependent variable. Second, the World Bank’s data on access to credit, electricity and contract enforcement in Africa were also employed as explanatory variables. Third, the Ibrahim Index of African Governance was used as an explanatory variable. Finally, country-specific data on four control variables (GDP, foreign direct investment, population and education) were gathered and analysed.

Findings

To support entrepreneurship development, Africa needs broad financial inclusion and state institutions that are more effective at enforcing contracts. Access to credit was non-significant and therefore did not contribute to the dependent variable (entrepreneurship quality and depth of entrepreneurial support in Africa). Access to electricity and political governance were statistically significant and correlated positively with the dependent variables. Finally, contract enforcement was partially significant and contributed to the dependent variable.

Research limitations/implications

A lack of GEI data for all 54 African countries limited this study to only 35 African countries: 31 in sub-Saharan Africa and 4 in North Africa. Therefore, the generalisability of this study’s findings to the whole of Africa might be limited. Second, this study depended on indexes for this study. Therefore, any inconsistencies in the index aggregation if any could not be authenticated. This study has practical implications for the development of entrepreneurship in Africa. Public and private institutions for credit delivery, contract enforcement and the provision of utility services such as electricity are crucial for entrepreneurship development.

Originality/value

The institutional void is a challenge for Africa. This study highlights the weak, corrupt nature of African institutions that supposedly support MSME growth. Effective entrepreneurship development in Africa depends on the presence of a supportive institutional infrastructure. This study engages institutional theory to explain the role of institutional factors such as state institutions, financial institutions, utility providers and markets in entrepreneurship development in Africa.
Share experiences: receiving word of mouth and its effect on relationships with donors
Authors: Sundermann Larissa M.
Published: December 2017

Purpose

Although antecedents and consequences for the sender of word of mouth (WOM) are well evaluated in many research fields, non-profit service research focusing on consequences for WOM receivers is limited. Thus, the purpose of this paper is to provide evidence for the positive effect that WOM has on commitment, trust, satisfaction and identification (relationship-related factors) and on intentional loyalty of blood donors. Furthermore, the role of the social reference group and the incentive ethics are analysed.

Design/methodology/approach

Blood donors of the German Red Cross Blood Donor Service were invited to take part in an online survey during May/June 2016. A total of 702 (23.74 per cent) blood donors, who first donated in 2015/2016, participated. The data were analysed using partial least squares structural equation modelling.

Findings

The results provide evidence that the mere presence of receiving WOM positively influences commitment, satisfaction and identification as well as intentional loyalty. The negative moderation effect of incentive ethics was partially confirmed.

Practical implications

This study recommends using WOM approaches to bind donors but first evaluating the exact consequences of provided WOM rewards. WOM is an effective strategy, and non-profit organizations (NPOs) should use this to strengthen their relationship with donors.

Originality value

The paper provides and tests a theoretical framework to evaluate the impact of receiving WOM on relationship-related factors and intentional loyalty. It fills a gap in current discussions about the effectiveness of WOM as a marketing strategy to strengthen donor–NPO relationships.
Customer Service and Satisfaction: Competitive Advantage and Beyond
Authors: Bazan Stanley
Published: December 2017

This article examines how excellence in customer service and satisfaction can be a major source of competitive advantage and profits for small businesses. The costs and causes of poor service and satisfaction are discussed and special emphasis is given to the value of the lifelong customer. Methods to pursue the goal of completely satisfying customers 100 percent of the time are examined. Leadership, aggressive problem solving, problem-solving teams, and assessment of customer service are among the topics reviewed.
Spatial dynamics of habitat use informs reintroduction efforts in the presence of an invasive predator
Authors: Rehm Evan M. , Balsat Mallory B. , Lemoine Nathan P. , Savidge Julie A.
Published: December 2017

Islands experience major impacts from introduced species, especially nocturnal predators. The brown tree snake (Boiga irregularis) extirpated almost the entire native avifauna on Guam after introduction. Reintroductions from neighbouring islands can restore bird communities but will take place in heavily managed units where snake populations can be controlled. Yet, reintroductions often proceed without relevant biological information such as habitat and space use when nocturnal predators are present. To guide efforts, we studied the avian frugivore community's diurnal and nocturnal habitat and space use on the island of Saipan, where the snake is absent.

Using radiotelemetry and a Bayesian framework, we compared data typically accessible to resource managers (diurnal home range [DHR] and habitat selection), which often form the basis of reintroduction plans. We contrasted this with data on nocturnal habitat use that is often not available but relevant when nocturnal predation threat is high.

Diurnal home range size varied within and among species with Micronesian Starlings (Aplonis opaca) having DHRs at least 45 ha larger than other species. For all species, night roost locations were generally spatially clustered within a DHR and covered a smaller spatial extent. Two species had higher probabilities of roosting outside DHR boundaries but, when outside, roosts were often within 200 m of the DHR boundary. All species selected forested habitats during day and night, with some species choosing native forest over non‐native habitat.

Synthesis and applications. If individuals roosted randomly throughout diurnal home ranges (DHRs), landscape‐level suppression of the brown tree snake on Guam might be the only viable option for reintroductions. However, we found that all species showed clustered roosting and high site fidelity. If site fidelity is common, then individuals that roost within fenced areas where snake populations are severely reduced will experience high survival even if diurnal home ranges extend into the surrounding unprotected matrix. There was a large overlap in habitat selection during day and night, indicating managed areas should be composed of native forest with non‐native forests of secondary importance. In systems with nocturnal predators, understanding variability in diurnal and nocturnal habitat use could lead to better informed management decisions.
Development and characterisation of a sugar‐free milk‐based dessert formulation with fig (Ficus carica L.) and carboxymethylcellulose
Authors: Jahromi Mastaneh , Niakousari Mehrdad
Published: December 2017

The objective of this study was to develop an optimum formula for ‘Shir Anjir’, an Iranian dessert containing milk, dried fig (13, 16.5, 20%) and carboxymethylcellulose (CMC) (0, 0.35, 0.7%) with no added sugar. Apparent viscosity, flow behaviour indices, pH, acidity (% lactic acid), total solid and colour parameters were compared. Sensory tests were performed to evaluate degree of liking of colour, appearance, taste, texture, mouthfeel and general acceptance. Figs and CMC influenced the dessert's characteristics. The most popular formula contained milk, 16.5% figs and 0.7% CMC and had an apparent viscosity of 3.78 Pa·s at 5 °C, exhibiting a shear‐thinning behaviour.