bluuebunny/crossref_metadata_2025 huggingface dataset:
Beyond parallel evolution: when several species colonize the same environmental gradient
Authors: Le Moan Alan , Gaggiotti Oscar , Henriques Romina , Martinez Paulino , Bekkevold Dorte , Hemmer-Hansen Jakob
Published: June 2019

Genomic signatures associated with population divergence, speciation and the evolutionary mechanisms responsible for these are key research topics in evolutionary biology. Evolutionary radiations and parallel evolution have offered opportunities to study the role of the environment by providing replicates of ecologically driven speciation. Here, we apply an extension of the parallel evolution framework to study replicates of ecological speciation where multiple species went through a process of population divergence during the colonization of a common environmental gradient. We used the conditions offered by the North Sea – Baltic Sea environmental transition zone and found clear evidence of population structure linked to the Baltic Sea salinity gradient in four flatfish species. We found highly heterogeneous signatures of population divergence within and between species, and no evidence of parallel genomic architecture across species associated with the divergence. Analyses of demographic history suggest that Baltic Sea lineages are older than the age of the Baltic Sea itself. In most cases, divergence appears to involve reticulated demography through secondary contact, and our analyses revealed that genomic patterns of divergence were likely the result of a combination of effects from past isolation and subsequent adaptation to a new environment. In one case, we identified two large structural variants associated with the environmental gradient, where populations were inferred to have diverged in the presence of gene flow. Our results highlight the heterogeneous genomic effects associated with complex interplays of evolutionary forces, and stress the importance of genomic background for studies of parallel evolution.
Transposons played a major role in the diversification between the closely related almond (Prunus dulcis) and peach (P. persica) genomes: Results from the almond genome sequence
Authors: Alioto Tyler , Alexiou Konstantinos , Bardil Amélie , Barteri Fabio , Castanera Raúl , Cruz Fernando , Dhingra Amit , Duval Henri , Fernández i Martí Ángel , Frias Leonor , Galán Beatriz , Garcia José L. , Howad Werner , Garrido Jèssica Gómez , Gut Marta , Julca Irene , Morata Jordi , Puigdomènech Pere , Ribeca Paolo , Rubio Cabetas María José , Vlasova Anna , Wirthensohn Michelle , Garcia-Mas Jordi , Gabaldón Toni , Casacuberta Josep M. , Arús Pere
Published: June 2019

Combining both short and long-read sequencing, we have estimated the almondPrunus dulciscv. Texas genome size in 235 Mbp and assembled 227.6 Mb of its sequence. The highly heterozygous compact genome of Texas comprises eight chromosomes, to which we have anchored over 91% of the assembly. We annotated 27,042 protein-coding genes and 6,800 non-coding transcripts. High levels of genetic variability were characterized after resequencing a collection of ten almond accessions. Phylogenomic comparison with the genomes of 16 other close and distant species allowed estimating that almond and peach diverged around 5.88 Mya. Comparison between peach and almond genomes confirmed the high synteny between these close relatives, but also revealed high numbers of presence-absence variants, many attributable to the movement of transposable elements (TEs). The number and distribution of TEs between peach and almond was similar, but the history of TE movement was distinct, with peach having a larger proportion of recent transpositions and almond preserving a higher level of polymorphism in the older TEs. When focusing on specific genes involved in key characters such as the bitter vs. sweet kernel taste and the formation of a fleshy mesocarp, we found that for one gene associated with the biosynthesis of amygdalin that confers the bitter kernel taste, several TEs were inserted in its vicinity only in sweet almond cultivars but not in bitter cultivars andPrunusbitter kernel relatives, includingP. webbii,P. mume, and other species like peach and cherry. TE insertions likely to produce affects in the expression of six more genes involved in the formation of the fleshy mesocarp were also identified. Altogether, our results suggest a key role of TEs in the recent history and diversification of almond with respect to peach.
Identifying and removing widespread signal deflections from fMRI data: Rethinking the global signal regression problem
Authors: Aquino Kevin M. , Fulcher Ben D. , Parkes Linden , Sabaroedin Kristina , Fornito Alex
Published: June 2019

One of the most controversial procedures in the analysis of resting-state functional magnetic resonance imaging (rsfMRI) data is global signal regression (GSR): the removal, via linear regression, of the mean signal averaged over the entire brain, from voxel-wise or regional time series. On one hand, the global mean signal contains variance associated with respiratory, scanner-, and motion-related artifacts. Its removal via GSR improves various quality control metrics, enhances the anatomical specificity of functional connectivity patterns, and can increase the behavioural variance explained by such patterns. On the other hand, GSR alters the distribution of regional signal correlations in the brain, can induce artifactual anticorrelations, may remove real neural signal, and can distort case-control comparisons of functional-connectivity measures. Global signal fluctuations can be identified by visualizing a matrix of colour-coded signal intensities, called a carpet plot, in which rows represent voxels and columns represent time. Prior to GSR, large, periodic bands of coherent signal changes that affect most of the brain are often apparent; after GSR, these apparent global changes are greatly diminished. Here, using three independent datasets, we show that reordering carpet plots to emphasize cluster structure in the data reveals a greater diversity of spatially widespread signal deflections (WSDs) than previously thought. Their precise form varies across time and participants and GSR is only effective in removing specific kinds of WSDs. We present an alternative, iterative correction method called Diffuse Cluster Estimation and Regression (DiCER), that identifies representative signals associated with large clusters of coherent voxels. DiCER is more effective than GSR at removing diverse WSDs as visualized in carpet plots, reduces correlations between functional connectivity and head-motion estimates, reduces inter-individual variability in global correlation structure, and results in comparable or improved identification of canonical functional-connectivity networks. All code for implementing DiCER and replicating our results is available at https://github.com/BMHLab/DiCER.
Efficient small-scale conjugation of DNA to primary antibodies for multiplexed cellular targeting
Authors: Cremers Glenn A.O. , Rosier Bas J.H.M. , Brillas Roger Riera , Albertazzi Lorenzo , de Greef Tom F.A.
Published: June 2019

The combination of the specificity of antibodies and the programmability of DNA nanotechnology has provided the scientific community with a powerful tool to label and unambiguously distinguish a large number of subcellular targets using fluorescence-based read-out methods. While primary antibodies are commercially available for a large class of targets, a general stoichiometric site-specific DNA labeling strategy for this affinity reagent is lacking. Here, we present a universal, site-selective, conjugation method using a small photocrosslinkable protein G adaptor that allows labeling of antibodies of different host species with a controlled number of short oligonucleotides (ODNs). Importantly, we illustrate that this conjugation method can be directly performed on commercially-available primary antibodies, on a small scale and without cross-reactivity towards other proteins, such as bovine serum albumin. In addition, we present a general, benchtop-compatible strategy to purify DNA-labeled antibodies without loss of function. The application of protein G-ODN labeled primary antibodies is demonstrated by employing three well-known methods for detecting subcellular targets using fluorescent read-out, including flow cytometry, DNA-PAINT, and dSTORM. This work thus establishes a general and efficient platform for the synthesis of a library of unique ODN-antibody conjugates, facilitating the broader use of DNA-based programmable tags for multiplexed labeling to identify subcellular features with nanometer-precision, improving our understanding of cellular structure and function.
Coordination difficulties, IQ and psychopathology in children with high-risk Copy Number Variants
Authors: Cunningham Adam C , Hall Jeremy , Owen Michael J , van den Bree Marianne B M
Published: June 2019

Background

The prevalence and impact of motor coordination difficulties in children with Copy Number Variants that are associated with high risk of neurodevelopmental disorder (ND-CNVS) remain unknown. The present study aims to advance understanding of motor coordination difficulties in children with ND-CNVs and establish relationships with IQ and psychopathology.

Methods

169 children with a ND-CNV (67% male, median age 8.88 years, range 6.02-14.81) and 57 closest-in-age unaffected siblings (controls; 55% male, median age 10.41 years, SD=3.04, range 4.89-14.75) were assessed with the Developmental Coordination Disorder Questionnaire, alongside psychiatric interviews, and standardised assessments of IQ.

Results

91% of children with an ND-CNV screened positive for coordination problems, compared to 19% of unaffected sibling controls (OR=42.53, p<.001). There was no difference in coordination ability between ND-CNV genotypes (F=1.47, p=.184). Poorer motor coordination in the ND-CNV group was associated with greater numbers of ADHD (p=.021) and autism spectrum disorder trait (p<.001) symptoms, along with lower full-scale (p=.011), performance (p=.015), and verbal IQ (p=.036). Mediation analysis indicated that coordination ability was a full mediator of anxiety symptoms (69% mediated, p=.012), and a partial mediator of ADHD (51%, p=.001) and ASD trait symptoms (66%, p<.001) along with FSIQ (40%, p=.002) PIQ (40%, p=.005) and VIQ (38%, p=.006) scores.

Conclusions

The findings indicate that poor motor coordination is highly prevalent and closely linked to risk of mental health disorder and lower intellectual function. Future research should explore whether early interventions for poor coordination ability could ameliorate neurodevelopmental risk more generally.
Retroviral integration into nucleosomes through DNA looping and sliding along the histone octamer
Authors: Wilson Marcus D. , Renault Ludovic , Maskell Daniel P. , Ghoneim Mohamed , Pye Valerie E. , Nans Andrea , Rueda David S. , Cherepanov Peter , Costa Alessandro
Published: June 2019

Retroviral integrase can efficiently utilise nucleosomes for insertion of the reverse-transcribed viral DNA. In face of the structural constraints imposed by the nucleosomal structure, integrase gains access to the scissile phosphodiester bonds by lifting DNA off the histone octamer at the site of integration. To clarify the mechanism of DNA looping by integrase, we determined a 3.9 Å resolution structure of the prototype foamy virus intasome engaged with a nucleosome core particle. The structural data along with complementary single-molecule Förster resonance energy transfer measurements reveal twisting and sliding of the nucleosomal DNA arm proximal to the integration site. Sliding the nucleosomal DNA by approximately two base pairs along the histone octamer accommodates the necessary DNA lifting from the histone H2A-H2B subunits to allow engagement with the intasome. Thus, retroviral integration into nucleosomes involves the looping-and-sliding mechanism for nucleosomal DNA repositioning, bearing unexpected similarities with chromatin remodelers.
RedMed: Extending drug lexicons for social media applications
Authors: Lavertu Adam , Altman Russ B
Published: June 2019

Social media has been identified as a promising potential source of information for pharmacovigilance. The adoption of social media data has been hindered by the massive and noisy nature of the data. Initial attempts to use social media data have relied on exact text matches to drugs of interest, and therefore suffer from the gap between formal drug lexicons and the informal nature of social media. The Reddit comment archive represents an ideal corpus for bridging this gap. We trained a word embedding model, RedMed, to facilitate the identification and retrieval of health entities from Reddit data. We compare the performance of our model trained on a consumer-generated corpus against publicly available models trained on expert-generated corpora. Our automated classification pipeline achieves an accuracy of 0.88 and a specificity of >0.9 across four different term classes. Of all drug mentions, an average of 79% (±0.5%) were exact matches to a generic or trademark drug name, 14% (±0.5%) were misspellings, 6.4% (±0.3%) were synonyms, and 0.13% (±0.05%) were pill marks. We find that our system captures an additional 20% of mentions; these would have been missed by approaches that rely solely on exact string matches. We provide a lexicon of misspellings and synonyms for 2,978 drugs and a word embedding model trained on a health-oriented subset of Reddit.
Kappa Opioid Receptor and Dynorphin Signaling in the Central Amygdala Regulates Alcohol Intake
Authors: Bloodgood Daniel W. , Pati Dipanwita , Pina Melanie M. , Neira Sofia , Hardaway J. Andrew , Desai Shivani , Boyt Kristen M. , Palmiter Richard D. , Kash Thomas L.
Published: June 2019

Excessive alcohol drinking has been shown to modify brain circuitry to predispose individuals for future alcohol abuse. Previous studies have implicated the central nucleus of the amygdala (CeA) as an important site for mediating the somatic symptoms of withdrawal and for regulating alcohol intake. In addition, recent work has established a role for both the Kappa Opioid Receptor (KOR) and its endogenous ligand dynorphin in mediating these processes. However, it is unclear whether these effects are due to dynorphin or KOR arising from within the CeA itself or other input brain regions. To directly examine the role of preprodynorphin (PDYN) and KOR expression in CeA neurons, we performed region-specific conditional knockout of these genes and assessed the effects on the Drinking in the Dark (DID) and Intermittent Access (IA) paradigms. We then examined the effects of DID on PDYN and KOR modulation of CeA circuit physiology. Conditional gene knockout resulted in sex-specific responses wherein PDYN knockout decreased alcohol drinking in both male and female mice, whereas KOR knockout decreased drinking in males only. We also found that neither PDYN nor KOR knockout protected against anxiety caused by alcohol drinking. Lastly, a history of alcohol drinking did not alter synaptic transmission in PDYN neurons in the CeA of either sex, but excitability of PDYN neurons was increased in male mice only. Taken together, our findings indicate that PDYN and KOR signaling in the CeA plays an important role in regulating excessive alcohol consumption and highlight the need for future studies to examine how this is mediated through downstream effector regions.
Patterns of microbial colonization of human bone from surface-decomposed remains
Authors: Emmons Alexandra L. , Mundorff Amy Z. , Keenan Sarah W. , Davoren Jonathan , Andronowski Janna , Carter David O. , DeBruyn Jennifer M.
Published: June 2019

Microbial colonization of bone is an important mechanism of post-mortem skeletal degradation. However, the types and distributions of bone and tooth colonizing microbes are not well characterized. It is unknown if microbial communities vary in abundance or composition between bone element types, which could help explain patterns of human DNA preservation. The goals of the present study were to (1) identify the types of microbes capable of colonizing different human bone types and (2) relate microbial abundances, diversity, and community composition to bone type and human DNA preservation. DNA extracts from 165 bone and tooth samples from three skeletonized individuals were assessed for bacterial loading and microbial community composition and structure. Random forest models were applied to predict operational taxonomic units (OTUs) associated with human DNA concentration. Dominant bacterial bone colonizers were from the phyla Proteobacteria (36%), Actinobacteria (23%), Firmicutes (13%), Bacteroidetes (12%), and Planctomycetes (4.4%). Eukaryotic bone colonizers were from Ascomycota (40%), Apicomplexa (21%), Annelida (19%), Basidiomycota (17%), and Ciliophora (14%). Bacterial loading was not a significant predictor of human DNA concentration in two out of three individuals. Random forest models were minimally successful in identifying microbes related to patterns of DNA preservation, complicated by high variability in community structure between individuals and body regions. This work expands on our understanding of the types of microbes capable of colonizing human bone and contributing to human skeletal DNA degradation.
Development of a multi-locus typing scheme for anEnterobacteriaceaelinear plasmid that mediates inter-species transfer of flagella
Authors: Robertson James , Lin Janet , Wren-Hedegus Amie , Arya Gitanjali , Carrillo Catherine , Nash John H.E.
Published: June 2019

Due to the public health importance of flagellar genes for typing, it is important to understand mechanisms that could alter their expression or presence. Phenotypic novelty in flagellar genes arise predominately through accumulation of mutations but horizontal transfer is known to occur. A linear plasmid termed pBSSB1 previously identified inSalmonellaTyphi, was found to encode a flagellar operon that can mediate phase variation, which results in the rare z66 flagella phenotype. The identification and tracking of homologs of pBSSB1 is limited because it falls outside the normal replicon typing schemes for plasmids. Here we report the generation of nine new pBSSB1-family sequences using Illumina and Nanopore sequence data. Homologs of pBSSB1 were identified in 154 genomes representing 25 distinct serotypes from 67,758Salmonellapublic genomes. Pangenome analysis of pBSSB1-family contigs was performed using Roary and we identified three core genes amenable to a minimal MLST scheme. Population structure analysis based on the newly developed MLST scheme identified three major lineages representing 35 sequence types, and the distribution of these sequence types was found to span multiple serovars across the globe. This MLST scheme has shown utility in tracking and subtyping pBSSB1-family plasmids and it has been incorporated into the plasmid MLST database under the name “pBSSB1-family”.
Satellite glial cells modulate cholinergic transmission between sympathetic neurons
Authors: Enes Joana , Sona Surbhi , Gerard Nega , Mitchell Alexander C. , Haburcak Marian , Birren Susan J.
Published: June 2019

Postganglionic sympathetic neurons and satellite glial cells are the two major cell types of the peripheral sympathetic ganglia. Sympathetic neurons project to and provide neural control of peripheral organs and have been implicated in human disorders ranging from cardiovascular disease to peripheral neuropathies. Here we show that satellite glia regulate postnatal development and activity of sympathetic neurons, providing evidence for local ganglionic control of sympathetic drive. We show changes in the cellular architecture of the rat sympathetic ganglia during the postnatal period, with satellite glia enwrapping sympathetic neuronal somata during a period of neuronal hypertrophy. In culture, satellite glia contribute to neuronal survival, promote synapse formation and play a modulatory role in neuron-to-neuron cholinergic neurotransmission, consistent with the close contact seen within the ganglia. Cultured satellite glia make and release neurotrophins, which can partially rescue the neurons from nerve growth factor deprivation. Electrophysiological recordings and immunocytochemical analysis on cultured sympathetic neurons show that satellite glial cells influence synapse number and total neuronal activity with little effect on neuronal intrinsic excitability. Thus, satellite glia play an early and ongoing role within the postnatal sympathetic ganglia, expanding our understanding of the contributions of local and target-derived factors in the regulation of sympathetic neuron function.
The effects of arm swing amplitude and lower-limb asymmetry on gait stability
Authors: Hill Allen , Nantel Julie
Published: June 2019

Changes to arm swing and gait symmetry are symptomatic of several pathological gaits associated with reduced stability. The purpose of this study was to examine the relative contributions of arm swing and gait symmetry towards gait stability. We theorized that actively increasing arm swing would increase gait stability, while asymmetric walking would decrease gait stability. Fifteen healthy, young adults (23.4 ± 2.8 yrs) walked on a split-belt treadmill under symmetric (1.2 m/s) and asymmetric walking (left/right, 5:4 speed ratio) with three different arm swings: held, normal, and active. Trunk local dynamic stability, inter-limb coordination, and spatiotemporal gait variability and symmetry were measured. Active arm swing resulted in improved local trunk stability, increased gait variability, and decreased inter-limb coordination (p < .013). The changes in local trunk stability and gait variability during active arm swing suggests that these metrics quantify fundamentally different aspects of stability and are not always comparable. Split-belt walking caused reduced local trunk stability, increased gait variability, and increased lower limb asymmetry (p < .003). However, the arm swing symmetry was unaffected by gait asymmetry, this suggests that deficits in gait stability in pathological gaits may be linked to increases in gait asymmetry rather than increases in arm swing asymmetry.
Investigation of inkjet printed path resistance in the context of manufacture and flexible application
Authors: Tomaszewski Grzegorz , Potencki Jerzy , Błąd Grzegorz , Wałach Tadeusz , Gajór Grzegorz , Pietrikova Alena , Lukacs Peter
Published: June 2019

Purpose

The purpose of this paper is to study the repeatability of path manufacturing in the drop on demand inkjet printing process and the influences of environmental and application factors on path resistance.

Design/methodology/approach

Paths were printed as multiline paths in packets one-, two- and three-layer paths on polyimide substrates using nanoparticle silver ink. The sintering conditions were determined experimentally. The paths were subjected to climatic and shock exposures and to bending processes. The resistance, profile and width of the paths were measured and analyzed. The temperature distribution for electrically heated paths was measured to identify the defects.

Findings

This research shows the repeatability of printing processes and identifies the sources that cause diversification in path parameters after the whole technological process. The influence of shock, climatic and mechanical exposures on path electrical properties is indicated. An effective method for identifying defects thermally is shown.

Research limitations/implications

The research could have limited universality by arbitrarily use of substrate material, ink, printhead, process parameters and kind of sample exposures.

Practical implications

The research includes practically useful information about the width, thickness, defects and resistances and their changes during a typical application for a path printed with different technological parameters.

Originality/value

This research presents the results of original empirical research on problems concerning the manufacture of paths with uniform parameters and shows how path parameters will change under exposures that may occur in a typical application. The research combines both production and application aspects.
Stability investigations based on two-port describing functions
Authors: Ladvanszky Janos
Published: June 2019

Purpose

Stability of a nonlinear, tuned amplifier has been investigated based on the describing function method. On stability, this paper means global asymptotic stability. The tuned amplifier comprises a saturated amplifying device with feedback and two resonators, at the input and the output. Describing function method here means introduction of the two-port describing functions.

Design/methodology/approach

Describing function method is applied, extended for two ports. Results from complex analysis and matrix algebra are heavily used. The two resonators have identical resonant frequency and bandwidth. Instability is represented by non-vanishing output perturbation for zero-input perturbation. Applying a simple transistor model with saturation and feedback, stability is analyzed in the form of output voltage as a function of input voltage.

Findings

Two-port scattering and admittance describing functions have been introduced. At a certain input voltage amplitude, instability appears in the form of unwanted sidebands, then at a higher input voltage, instability disappears, in good agreement with experiments. The hand calculated stability limits are in good agreement with the computer analysis.

Originality/value

The paper is based on an early publication of the author (Baranyi and Ladvánszky, 1984). Here, the full material is presented, explained step by step, extended and revised. All neglections that were earlier made in the author’s paper have been avoided here. This paper has significant tutorial value as well.
The influence of the diffusion of food safety information through social media on consumers’ purchase intentions
Authors: Cui Li , Jiang Haiyang , Deng Hepu , Zhang Tao
Published: June 2019

Purpose

The purpose of this paper is to investigate how the diffusion of food safety information through social media affects customers’ purchase intentions in China. This leads to the identification of the critical factors that impact the purchase intention of individual consumer through the diffusion of food safety information using social media in China.

Design/methodology/approach

A research model is proposed based on a comprehensive review of the related studies. Such a model is then tested and validated using structural equation modeling based on the survey of 199 individuals who have experience in purchasing food products online while having social media accounts.

Findings

The study reveals that friend recommendation and perceived risk directly affect consumers’ purchase intentions and opinion leader recommendation, quality of information, credibility of information and demand for information indirectly affect consumers’ purchase intentions through the diffusion of food safety information using social media in China.

Originality/value

This study is the first of this kind in China for exploring the critical factors that affect consumers’ purchase intentions through the diffusion of food safety information using social media. The findings of the study are significant for the government and food enterprises to make a full use of the advantages of social media to improve the communication of food safety information in ensuring the safety of the food supply in China.
Research on the simplified vehicle window buffeting noise with a modified LRN CLES model using a transition-code based method
Authors: Chen Zhen , Gu Zhengqi , Wang Zhonggang
Published: June 2019

Purpose

This paper aims to propose a precise turbulence model for vehicle aerodynamics, especially for vehicle window buffeting noise.

Design/methodology/approach

Aiming at the fact that commonly used turbulence models cannot precisely predict laminar-turbulent transition, a transition-code-based improvement is introduced. This improvement includes the introduction of total stress limitation (TSL) and separation-sensitive model. They are integrated into low Reynolds number (LRN) k-ε model to concern transport properties of total stress and precisely capture boundary layer separations. As a result, the ability of LRN k-ε model to predict the transition is improved. Combined with the constructing scheme of constrained large-eddy simulation (CLES) model, a modified LRN CLES model is achieved. Several typical flows and relevant experimental results are introduced to validate this model. Finally, the modified LRN CLES model is used to acquire detailed flow structures and noise signature of a simplified vehicle window. Then, experimental validations are conducted.

Findings

Current results indicate that the modified LRN CLES model is capable of achieving acceptable accuracy in prediction of various types of transition at various Reynolds numbers. And, the ability of this model to simulate the vehicle window buffeting noise is greater than commonly used models.

Originality/value

Based on the TSL idea and separation-sensitive model, a modified LRN CLES model concerning the laminar-turbulent transition for the vehicle window buffeting noise is first proposed.
Homotopy perturbation method for peristaltic motion of gold-blood nanofluid with heat source
Authors: Ebaid Abdelhalim , Aljohani Abdulrahman F. , Aly Emad H.
Published: June 2019

Purpose

This paper aims to investigate the impacts of the gold nanoparticles on the peristaltic flow and heat transfer of blood in the presence of heat source. This element has been chosen because on comparing with the other common nanoparticles, gold nanoparticles are preferred due to their unique properties in absorbing the temperature when a heat source exists.

Design/methodology/approach

On simplifying the governing equations under the assumption of long-wavelength and low-Reynolds number approximations, the resulted system has been solved by applying the homotopy perturbation method. Then, detailed physical discussion has been introduced through several plots while focusing on the consequences of the current results on the treatment of cancer.

Findings

The present results revealed that the heat source has a great effect on the blood velocity, blood temperature and concentration of the gold nanoparticles within the artery/vein cavity when represented as asymmetric channel. Moreover, the accuracy of the current solutions was validated through several plots of the remainder error for each studied phenomenon.

Originality/value

The current idea gives some light on the attempts of using the gold nanoparticles in the treatment of cancer and therefore may lead to possible applications for diagnosis/therapy of the human cancer. To the best of authors’ knowledge, this is novel, very efficient and applicable.
Simulation of phase separation in a Van der Waals fluid under gravitational force with Lattice Boltzmann method
Authors: Fogliatto Ezequiel Oscar , Clausse Alejandro , Teruel Federico Eduardo
Published: June 2019

Purpose

This paper aims to assess the accuracy of Lattice Boltzmann method (LBM) for numerical simulation of the stratification of a Van der Waals (VdW) fluid subjected to a gravity field and non-uniform temperature distribution. A sensitivity analysis of the influence of the pseudopotential parameters and the grid resolution is presented. The effect of gravity force on interface densities, density profiles and liquid volume fraction is studied.

Design/methodology/approach

The D2Q9 multiple-relaxation-time pseudopotential LBM for two-phase flow is proposed to simulate the phase separation. The analytical solution for density profiles in a one-dimensional problem is derived and used as a benchmark case to validate the numerical results.

Findings

The numerical results reproduce the analytical density profiles with great accuracy over a wide range of simulation conditions, including variations of the gravity and temperature fields. Particularly, the numerical simulations are able to represent the effect of gravity on the existence and position of the liquid–vapor boundary of an ideal pure substance in thermodynamic equilibrium. The sensitivity of the results to variations of the calibration parameters of the VdW pseudopotential was assessed.

Research limitations/implications

The numerical simulations were performed assuming a VdW fluid in a 2-D cavity with one periodic direction for which analytical solutions for benchmarking purposes are possible to obtain.

Originality/value

The following fundamental question is addressed: Is the pseudopotential LBM capable of simulating accurately the liquid–vapor equilibrium under gravity forces and temperature gradients? Moreover, regarding that the pseudopotential model requires the calibration of several internal parameters to achieve thermodynamic consistency, the sensitivity of the results to variations of these parameters is assessed.
Scale to measure tourist value of destination restaurant service
Authors: Kim Og Yeon , Seo Sunhee , Nurhidayati Vieta Annisa
Published: June 2019

Purpose

The purpose of this study is to develop a measurement scale to explain how international tourists, as consumers at destination restaurants, evaluate their dining experiences.

Design/methodology/approach

The measurement scale was developed using a three-stage process: initial item generation, scale development and scale evaluation. A total of 369 self-administered questionnaires validated the developed scale.

Findings

The results showed five dimensions of value of destination restaurant services: service quality value, authentic experience value, emotional experience value, social value and utility value. The scale, comprising 40 items, was reliable and valid for assessing the value of destination restaurant services.

Research limitations/implications

This scale revealed new items that help explain the value of various destination restaurant services among international tourists. The developed scale could be used to extend the research model with antecedents of value and consequences of value for destination restaurant services.

Practical implications

Considering the popularity of food tourism among international tourists, the developed scale should be useful in assessing how tourists value destination restaurant services, thereby helping restaurant managers create effective marketing strategies.

Originality/value

This study contributes with a new, reliable and valid measurement scale that was specifically developed to address the unique value of destination restaurant services.
Rebuilding a global brand under crisis – case of a global brand Maggi
Authors: Srivastava Rajesh Kumar
Published: June 2019

Purpose

The purpose of this paper is to study whether the controversy because of brand crisis based on quality had any impact on consumer brand equity, brand image, brand reliability, brand perception of quality, perceived value, brand sentiments and purchase behavior.

Design/methodology/approach

The research methodology consisted of two types of data: primary and secondary data. The secondary research consisted of social media brand sentiments and financial analysis. The primary research focused on perception study of brand quality, consumer brand equity, brand reliability, brand image, purchase and brand switch behavior.

Findings

Maggi used social media extensively to address the issue and re-build the brand reliability and confidence among its users. Communication strategy adopted by focusing on the past experience of consumers and using them as a spokesperson generated a positive sentiment towards the brand under crisis.

Research limitations/implications

While Maggi suffered the backlash because of the controversy across the length and breadth of India and was banned in a number of states, the author could conduct the primary research only in one city of the state of Maharashtra, Mumbai. The effectiveness of the survey was impacted because of the geographic limitations the author faced while collecting the responses. The survey would have definitely been more effective, with responses collected from different states and with more number of respondents. Fishbein is very old, from the 1980s, even though this theory has met the test of time. Application of the effect of experiences on experiential perceptions and how this influences value through networking could have been used to explain the same.

Practical implications

An important implication of this paper’s findings for practice, therefore, is that brands should incessantly strive to maintain the consumers’ level of trust, as it is essential for the preservation of the brand equity after a crisis. Crisis-stricken brands should safeguard their reputations from the negative effects of crises. It is even more important for any brand to act appropriately when the cause of the crisis is attributed to its actions and processes. Managers have to address the quality of products in case of brand crisis for restoring trust, image and reliability in the brand. Right type of communication to right targeted consumers will help in the restoration of the image, trust on the brand and bring back loyal customers. Managers have to build brand equity on a regular basis, as a strong brand can recover faster as seen from this paper.

Originality/value

This paper helps to upgrade the knowledge and understanding of the impact of the controversy on brand equity and image and how the crisis management strategy can be adopted to regain the mind share and equity. This paper will help the brands in the future to know how a crisis can be managed efficiently by drawing a cue from the strategies implemented by Maggi.
Promoting the image of a historic city for sustainable cultural tourism: the case of Tlemcen Capital of Islamic Culture 2011
Authors: Kherbouche Somia , Djedid Abdelkader
Published: June 2019

Purpose

Focussing on the event “Tlemcen Capital of Islamic Culture 2011”, the purpose of this paper is to examine the changing perception of the city’s image, assess its durability and determine its relationship with the development of sustainable cultural tourism.

Design/methodology/approach

This research is tested by an empirical study that combines a qualitative and a quantitative approach. The qualitative study is based on semi-directive interviews, whereas quantitative study is based on statistics from the Wilaya Tourism Department.

Findings

The results of this study indicate first of all that the perception of the city’s image by the inhabitants is not static and that it follows the same process of evolution of the perception of the image by tourists but in relation to other factors such as awareness and age. The second result shows that the sustainability of the image must be verified both inside and outside to achieve sustainable cultural tourism.

Originality/value

This study is in line with previous research with another point of view on the city’s image and another case study which is the historical city of Tlemcen. It serves to examine the evolution of the perception of the city’s image produced by the event and to assess its sustainability.
Strategies and measures directed towards overtourism: a perspective of European DMOs
Authors: Eckert Christian , Zacher Daniel , Pechlaner Harald , Namberger Philipp , Schmude Jürgen
Published: June 2019

Purpose

Due to both the new quality and intensity overtourism discussions have received, it is time to examine the question concerning the consequences this development has on destination level and how destinations can adjust their strategies for future development. This is especially important to consider, since overtourism can be seen as a fundamental issue for tourism development. First measures taken within destinations show that reactions are taking place, e.g. through access restrictions of frequently visited places. The purpose of this paper is to identify future-oriented strategies and to derive concrete measures in order to deal with overtourism on a destination level.

Design/methodology/approach

In total, 19 qualitative interviews with European destination managers were conducted and evaluated via the qualitative analysis method GABEK® with WinRelan® software.

Findings

The results show that various stakeholders are involved in overtourism, with the destination management organization being the central actor to deal with issues. It is challenging to choose between different strategies and measures, which always have to be considered in relation to the specific conditions of a destination and the perception level of overtourism. In order to face current developments, the initiation of a stakeholder dialog can be seen as a promising factor, but also as a challenging task.

Originality/value

Currently, a “wait-and-see-attitude” exists, where well-known destinations are cited as negative examples, but a serious examination related to one’s own destination has not yet been developed. This consideration should be seen as a prerequisite for future-oriented destination development, which takes the local population into account.
Extending the double jeopardy and duplication of purchase laws to the wine market
Authors: Wilson Damien , Winchester Maxwell
Published: June 2019

Purpose

This study aims to understand the market structure and explore the applicability of recognised generalisations to a European wine retail market. The study considers whether brands in European wine retailing follow the established double jeopardy and duplication of purchase laws, with the aim of investigating their limits so as to identify where market partitions are evident.

Design/methodology/approach

The researchers conducted a cross-purchasing analysis within the wine category over a 12-month period, using a customer panel of n = 25,000 across a chain of independent retail stores in an English-speaking European country. Analysis was conducted across purchases of the top 20 wine brands.

Findings

Consumer wine repurchase results confirmed a double jeopardy pattern. These consumers’ wine repurchasing behaviour from other top-20 wine brands could have generally been predicted in line with the duplication of purchase law. However, a small number of exceptions to these patterns were identified, suggesting the existence of market partitions.

Research limitations/implications

In this study, market partitions were evident for selected brands, a wine region and a common grape variety, Sauvignon blanc. Such exceptions illustrate that consumer purchase patterns can deviate from predictions, for a small number of brands in a consumer goods category than would be expected given duplication of purchase law norms. Such anomalies to empirical generalisations help demonstrate boundary conditions and lead further research on the market conditions required for such anomalies to be evident. Implications suggest that further research should be conducted on the product features creating market partitions.

Practical implications

The findings suggest that regional wines can appeal to a more clearly partitioned customer group within the clientele, but that substitution is noted among brands within regions.

Originality/value

To the best of the authors’ knowledge, this is the first study to use a large sample consumer database to determine the generalisability of two well-established empirical generalisations: the double jeopardy and duplication of purchase laws, to the wine retail market. Knowing these are applicable to the wine retail markets allows wine producers and retailers to predict expected repurchase and cross-purchasing norms.
Gender differentials and implicit feedback on online video content: enhancing user interest evaluation
Authors: Chong Woonkian , Rudkin Simon , Zhang Junhui
Published: June 2019

Purpose

Exponential growth in online video content makes viewing choice and video promotion increasingly challenging. While explicit recommendation systems have value, they inherently distract the user from normal behaviour and are open to numerous biases. To enhance user interest evaluation accuracy, the purpose of this paper is to comprehensively examine the relationship between implicit feedback and online video content, and reviews gender differentials in the interest indicated by a comprehensive set of viewer responses.

Design/methodology/approach

This paper includes 200 useable observations based on an experiment of user interaction with the Youku platform (one of the largest video-hosting websites in China). Logistic regression was employed for its simple interpretation to test the proposed hypotheses.

Findings

The findings demonstrate gender differentials in cursor movement behaviour, explainable via well-studied splits in personality, biological factors, primitive behaviour and emotion management. This work offers a solution to the sparsity of work on implicit feedback, contributing to the literature that combines explicit and implicit feedback.

Practical implications

This study offers a launch point for further work on human–computer interaction, and highlights the importance of looking beyond individual metrics to embrace wider human traits in video site design and implementation.

Originality/value

This paper links implicit feedback to online video content for the first time, and demonstrates its value as an interest capturing tool. By reviewing gender differentials in the interest indicated by a comprehensive set of viewer responses, this paper indicates how user characteristics remain critical. Consequently, this work signposts highly fruitful directions for both practitioners and researchers.
Dual mechanisms of reinforcement reward and habit in driving smartphone addiction
Authors: Chen Chongyang , Zhang Kem Z.K. , Gong Xiang , Lee Matthew
Published: June 2019

Purpose

In the limited existing research on smartphone addiction, reinforcement reward and automatic habit have been identified as two distinct underlying mechanisms. The purpose of this paper is to better understand the interaction between these two mechanisms, as well as role of smartphone features in activating different formation mechanisms.

Design/methodology/approach

An online survey with 379 samples was conducted to empirically validate the model. The data were analyzed by structural equation modeling approach.

Findings

The automatic habit strengthens the driving effects of reinforcement rewards (i.e. perceived enjoyment and mood regulation) on smartphone addiction. Smartphone features activate distinct underlying mechanisms. Value-added function facilitates the perception of reinforcement rewards, while convenience promotes the habit formation.

Originality/value

This study is one of the first ones that assess the interplay between the two formation mechanisms in the extant literature on smartphone addiction. This study also reveals the dangers of smartphone features which have always been regarded as advantages. The findings contribute to the current understandings of smartphone addiction.