bluuebunny/crossref_metadata_2025 huggingface dataset:
Mutational signatures of complex genomic rearrangements in human cancer
Authors: Bao Lisui , Zhong Xiaoming , Yang Yang , Yang Lixing
Published: May 2021

Complex genomic rearrangements (CGRs) are common in cancer and are known to form via two aberrant cellular structures—micronuclei and chromatin bridge. However, which mechanism is more relevant to CGR formation in cancer cells and whether there are other undiscovered mechanisms remain open questions. Here, we analyze 2,014 CGRs from 2,428 whole-genome sequenced tumors and deconvolute six CGR signatures based on the topology of CGRs. Through rigorous benchmarking, we show that our CGR signatures are highly accurate and biologically meaningful. Three signatures can be attributed to known biological processes—micronuclei- and chromatin-bridge-induced chromothripsis and extrachromosomal DNA. More than half of the CGRs belong to the remaining three newly discovered signatures. A unique signature (we named “hourglass chromothripsis”) with highly localized breakpoints and small amount of DNA loss is abundant in prostate cancer. Through genetic association analysis, we find SPOP as a candidate gene causing hourglass chromothripsis and playing important role in maintaining genome integrity. Our study offers valuable insights into the formation of CGRs.
Detection of fusion transcripts and their genomic breakpoints from RNA sequencing data
Authors: Hoogstrate Youri , Komor Malgorzata A. , Böttcher René , van Riet Job , van de Werken Harmen J. G. , van Lieshout Stef , Hoffmann Ralf , van den Broek Evert , Bolijn Anne S. , Dits Natasja , Sie Daoud , van der Meer David , Pepers Floor , Bangma Chris H. , van Leenders Geert J. L. H. , Smid Marcel , French Pim , Martens John W.M. , van Workum Wilbert , van der Spek Peter J. , Janssen Bart , Caldenhoven Eric , Rausch Christian , de Jong Mark , Stubbs Andrew P. , Meijer Gerrit A. , Fijneman Remond J.A. , Jenster Guido
Published: May 2021

Spliced fusion-transcripts are typically identified by RNA-seq without elucidating the causal genomic breakpoints. However, non poly(A)-enriched RNA-seq contains large proportions of intronic reads spanning also genomic breakpoints. Using 1.274 RNA-seq samples, we investigated what additional information is embedded in non poly(A)-enriched RNA-seq data. Here, we present our novel, graph-based, Dr. Disco algorithm that makes use of both intronic and exonic RNA-seq reads to identify not only fusion transcripts but also genomic breakpoints in gene but also in intergenic regions. Dr. Disco identified TMPRSS2-ERG fusions with genomic breakpoints and other transcribed rearrangements from multiple RNA-sequencing cohorts. In breast cancer and glioma samples Dr. Disco identified rearrangement hotspots near CCND1 and MDM2 and could directly associate this with increased expression. A comparison with matched DNA-sequencing revealed that most genomic breakpoints are not, or minimally, transcribed while also revealing highly expressed translocations missed by DNA-seq. By using the full potential of non poly(A)-enriched RNA-seq data, Dr. Disco can reliably identify expressed genomic breakpoints and their transcriptional effects.
A Meta-Analysis of fMRI Studies of Semantic Cognition in Children
Authors: Enge Alexander , Rahman Rasha Abdel , Skeide Michael A.
Published: May 2021

Our capacity to derive meaning from things that we see and words that we hear is unparalleled in other animal species and current AI systems. Despite a wealth of functional magnetic resonance imaging (fMRI) studies on where different semantic features are processed in the adult brain, the development of these systems in children is poorly understood. Here we conducted an extensive database search and identified 50 fMRI experiments investigating semantic world knowledge, semantic relatedness judgments, and the differentiation of visual semantic object categories in children (total N = 1,018, mean age = 10.1 years, range 4–15 years). Synthesizing the results of these experiments, we found consistent activation in the bilateral inferior frontal gyri (IFG), fusiform gyri (FG), and supplementary motor areas (SMA), as well as in the left middle and superior temporal gyri (MTG/STG). Within this system, we found little evidence for age-related changes across childhood and high overlap with the adult semantic system. In sum, the identification of these cortical areas provides the starting point for further research on the mechanisms by which the developing brain learns to make sense of its environment.
Rhizome trait scaling relationships are modulated by growth conditions and are linked to plant fitness
Authors: Thakur Dinesh , Münzbergová Zuzana
Published: May 2021

Background and Aim

Rhizomes are important organs allowing many clonal plants to persist and reproduce under stressful climates with longer rhizomes indicating enhanced ability of the plants to spread vegetatively. We do not however, know either how rhizome construction costs change with increasing length or vary with environmental conditions.

Methods

We analysed the rhizome length vs mass scaling relationship, the plasticity in the scaling relationships, their genetic basis, and how scaling relationships are linked to plant fitness. We used data from 275 genotypes of a clonal grass Festuca rubra originating from 11 localities and cultivated under four contrasting climates. Data were analysed using standard major axis regression, mixed-effect regression models and a structural equation model.

Key Results

Rhizome construction costs increased (i.e., lower specific rhizome length) with increasing length. The trait scaling relationships were modulated by cultivation climate and its effects also interacted with the climate of origin of the experimental plants. With increasing length, increasing moisture led to a greater increase in rhizome construction costs. Plants with lower rhizome construction costs showed significantly higher fitness.

Conclusions

This study suggests that rhizome scaling relationships are plastic, but also show genetic differentiation and are linked to plant fitness. Therefore, to persist under variable environments modulation in scaling relationships could be an important plants’ strategy.
Schema representations in distinct brain networks support narrative memory during encoding and retrieval
Authors: Masís-Obando Rolando , Norman Kenneth A. , Baldassano Christopher
Published: May 2021

Schematic prior knowledge can scaffold the construction of event memories during perception and also provide structured cues to guide memory search during retrieval. We measured the activation of story-specific and schematic representations using fMRI while participants were presented with 16 stories and then recalled each of the narratives, and related these activations to memory for specific story details. We predicted that schema representations in mPFC would be correlated with successful recall of story details. In keeping with this prediction, an anterior mPFC region showed a significant correlation between activation of schema representations at encoding and subsequent behavioral recall performance; however, this mPFC region was not implicated in schema representation during retrieval. More generally, our analyses revealed largely distinct brain networks at encoding and retrieval in which schema activation was related to successful recall. These results provide new insight into when and where event knowledge can support narrative memory.
Compensatory functional connectome changes in a rat model of traumatic brain injury
Authors: Yang Zhihui , Zhu Tian , Pompilus Marjory , Fu Yueqiang , Zhu Jiepei , Arjona Kefren , Arja Rawad Daniel , Grudny Matteo M. , Plant H. Daniel , Bose Prodip , Wang Kevin K. , Febo Marcelo
Published: May 2021

Penetrating cortical impact injuries alter neuronal communication beyond the injury epicenter, across regions involved in affective, sensorimotor, and cognitive processing. Understanding how traumatic brain injury (TBI) reorganizes local and brain wide nodal functional interactions may provide valuable quantitative parameters for monitoring pathological progression and functional recovery. To this end, we investigated spontaneous fluctuations in the functional magnetic resonance imaging (fMRI) signal obtained at 11.1 Tesla in rats sustaining controlled cortical impact (CCI) and imaged at 2- and 30-days post-injury. Graph theory-based calculations were applied to weighted undirected matrices constructed from 12,879 pairwise correlations between fMRI signals from 162 regions. Our data indicate that on days 2 and 30 post-CCI there is a significant increase in connectivity strength in nodes located in contralesional cortical, thalamic, and basal forebrain areas. Rats imaged on day 2 post-injury had significantly greater network modularity than controls, with influential nodes (with high eigenvector centrality) contained within the contralesional module and participating less in cross-modular interactions. By day 30, modularity and cross-modular interactions recover, although a cluster of nodes with low strength and low eigenvector centrality remain in the ipsilateral cortex. Our results suggest that changes in node strength, modularity, eigenvector centrality, and participation coefficient track early and late TBI effects on brain functional connectivity. We propose that the observed compensatory functional connectivity reorganization in response to CCI may be unfavorable to brain wide communication in the early post-injury period.
Deep Learning Assisted Mechanotyping of Individual Cells Through Repeated Deformations and Relaxations in Undulating Channels
Authors: Combs Cody T. , Seith Daniel D. , Bovyn Matthew J. , Gross Steven P. , Xie Xiaohui , Siwy Zuzanna S.
Published: May 2021

Mechanical properties of cells are important features that are tightly regulated, and are dictated by various pathologies. Deformability cytometry allows for the characterization of mechanical properties of hundreds of cells per second, opening the way to differentiating cells via mechanotyping. A remaining challenge for detecting and classifying rare sub-populations is the creation of a combined experimental and analysis protocol that would assure classification accuracy approaching 100%. In order to maximize the accuracy, we designed a microfluidic channel that subjects each cell to repeated deformations and relaxations. We also track the shape dynamics of individual cells with high time resolution, and apply sequence-based deep learning models for feature extraction. HL60 cells with and without treatment with cytochalasin D (cytoD), a reagent previously shown to perturb the actin network, were used as a model system to understand the classification potential of our approach. Multiple recurrent and convolutional neural network architectures were trained using time sequences of cell shapes, and shown to achieve high classification accuracy based on cytoskeletal properties alone. The best model classified the two sub-populations of HL60 cells with an accuracy of 95%. This work establishes the application of sequence-based deep learning models to dynamic deformability cytometry.
The mechanism of artemisinin resistance of Plasmodium falciparum malaria parasites originates in their initial transcriptional response
Authors: Zhu Lei , van der Pluijm Rob W. , Kucharski Michal , Nayak Sourav , Tripathi Jaishree , Nosten François , Faiz Abul , Amaratunga Chanaki , Lek Dysoley , Ashley Elizabeth A , Smithuis Frank , Phyo Aung Pyae , Lin Khin , Imwong Mallika , Mayxay Mayfong , Dhorda Mehul , Chau Nguyen Hoang , Thuy Nhien Nguyen Thanh , Newton Paul N , Jittamala Podjanee , Tripura Rupam , Pukrittayakamee Sasithon , Peto Thomas J , Miotto Olivo , Seidlein Lorenz von , Hien Tran Tinh , Ginsburg Hagai , Day Nicholas PJ , White Nicholas J. , Dondorp Arjen M , Bozdech Zbynek
Published: May 2021

The emergence and spread of artemisinin resistant Plasmodium falciparum, first in the Greater Mekong Subregion (GMS), and now in East Africa, is a major threat to global malaria eliminations ambitions. To investigate the artemisinin resistance mechanism, transcriptome analysis was conducted of 577 P. falciparum isolates collected in the GMS between 2016-2018. A specific artemisinin resistance-associated transcriptional profile was identified that involves a broad but discrete set of biological functions related to proteotoxic stress, host cytoplasm remodeling and REDOX metabolism. The artemisinin resistance-associated transcriptional profile evolved from initial transcriptional responses of susceptible parasites to artemisinin. The genetic basis for this adapted response is likely to be complex.

One sentence summary

The transcriptional profile that characterize artemisinin resistant infections with malaria parasites Plasmodium falciparum originates in the initial transcriptional response to the drug.
Diel CO2 fluctuations alter the molecular response of coral reef fishes to ocean acidification conditions
Authors: Schunter Celia , Jarrold Michael D. , Munday Philip L. , Ravasi Timothy
Published: May 2021

Environmental CO2 variation can modify the responses of marine organisms to ocean acidification, yet the underlying mechanisms for this effect remain unclear. On coral reefs, environmental CO2 fluctuates on a regular day-night cycle. Effects of future ocean acidification on coral reef fishes might therefore depend on their response to this diel cycle of CO2. To evaluate the effects on the brain molecular response, we exposed two common reef fishes (Acanthochromis polyacanthus and Amphiprion percula) to two projected future CO2 levels (750 and 1,000 μatm) under both stable and diel fluctuating conditions. We found a common signature to stable elevated pCO2 for both species, which included the downregulation of immediate early genes, indicating lower brain activity. The transcriptional program was more strongly affected by higher average CO2 in a stable treatment than for fluctuating treatments, however, the largest difference in molecular response was between stable and fluctuating CO2 treatments. This indicates that a response to a change in environmental CO2 conditions is different for organisms living in a fluctuating than in stable environments. The differential regulation was related to steroid hormones and circadian rhythm (CR). Both species exhibited a marked difference in the expression of CR genes among CO2 treatments, possibly accommodating a more flexible adaptive approach to acid-base control, which could explain reduced impairment. Our results suggest that environmental CO2 fluctuations might enable reef fishes to phase shift their clocks and anticipate CO2 changes, thereby avoiding impairments and more successfully adjust to ocean acidification conditions.
Genomic and physiological characterization of new Plant Growth Promoting Bacilli isolated from salt-pans
Authors: Petrillo Claudia , Castaldi Stefany , Lanzilli Mariamichela , Selci Matteo , Cordone Angelina , Giovannelli Donato , Isticato Rachele
Published: May 2021

Massive application of chemical fertilizers and pesticides has been the main strategy used to cope with the rising crop demands in the last decades. The indiscriminate use of chemicals while providing a temporary solution to food demand has led to a decrease in crop productivity and an increase in the environmental impact of modern agriculture. A sustainable alternative to the use of chemicals for crop production is the use of microorganisms naturally capable of enhancing plant growth and protecting crops from pests, known as Plant-Growth-Promoting Bacteria (PGPB). Aim of the present study was to isolate and characterize PGPB from salt-pans sand samples able to ameliorate plant fitness. To survive high salinity, salt-tolerant microbes produce a broad range of compounds with heterogeneous biological activities that are potentially beneficial for plant growth. We have isolated and screenedin vitroa total of 20 halophilic spore-forming bacteria for phyto-beneficial traits and compared the results with twoBacillirecently isolated from the rhizosphere of the same collection site and recently characterized as potential biocontrol agents. Whole-genome analysis on five selected halophilic strains confirmed the presence of numerous gene clusters with PGP and biocontrol functions and of novel secondary-metabolite biosynthetic genes potentially involved in plant growth promotion and protection. The predicted biocontrol potential was confirmed in dual culture assays against several phytopathogenic fungi and bacteria. Interestingly, the absence of predicted gene clusters with known biocontrol functions in some of the isolates was not predictive of thein vitroresults, supporting the need of combining laboratory assays and genome mining in PGPB identification for future applications.
Nuclear RNA concentration coordinates RNA production with cell size in human cells
Authors: Berry Scott , Müller Micha , Pelkmans Lucas
Published: May 2021

Unlike its DNA template, RNA abundance and synthesis rates increase with cell size, as part of a mechanism of cellular RNA concentration homeostasis. Here, we study this scaling phenomenon in human cells by combining genome-wide perturbations with quantitative single-cell measurements. Despite relative ease in perturbing RNA synthesis, we find that RNA concentrations remain highly constant. Systems-level analysis indicates that perturbations that would lead to increased nuclear mRNA abundance result in downregulation of mRNA synthesis. This is associated with reduced levels of several transcription-associated proteins and protein states that are normally coordinated with RNA production in single cells, including RNA polymerase II (Pol II) itself. Acute shut-down of nuclear RNA degradation, elevation of nuclear mRNA levels, and mathematical modelling indicate that mammalian cells achieve RNA concentration homeostasis by an mRNA-based negative feedback on transcriptional activity in the nucleus. Ultimately, this acts to robustly scale Pol II abundance with cell volume and coordinate mRNA synthesis and degradation.
Detection of Campylobacter in air samples from poultry houses using shot-gun metagenomics – a pilot study
Authors: Haverkamp Thomas H.A. , Spilsberg Bjørn , Johannessen Gro S. , Torp Mona , Sekse Camilla
Published: May 2021

Background

Foodborne pathogens such as Campylobacter jejuni are responsible for a large fraction of the gastrointestinal infections worldwide associated with poultry meat. Campylobacter spp. can be found in the chicken fecal microbiome and can contaminate poultry meat during the slaughter process. The current standard methods to detect these pathogens at poultry farms use fecal dropping or boot swaps in combination with cultivation / PCR. In this study, we have used air filters in combination with shotgun metagenomics for the detection of Campylobacter in poultry houses and MOCK communities to test the applicability of this approach for the detection of foodborne pathogens.

Results

The spiked MOCK communities showed that we could detect as little as 200 CFU Campylobacter per sample using our protocols. Since we were interested in detecting Campylobacter, a DNA extraction protocol for Gram negative bacteria was chosen, and as expected, we found that the DNA extraction protocol created a substantial bias affecting the community composition of the MOCK communities. It can be expected that the same bias is present for poultry house samples analyzed. We observed significant amounts of Campylobacter on the air filters using both real-time PCR as well as shotgun metagenomics, irrespective of the amount of spiked in Campylobacter cells, suggesting that the flocks in both houses harboured Campylobacter spp.. Interestingly, in both houses we find diverse microbial communities present in the indoor air. In addition, have we tested the Campylobacter detection rate using shotgun metagenomics by spiking with different levels of C. jejuni cells in both the mock and the house samples. This showed that even with limited sequencing Campylobacter is detectable in samples with low abundance.

Conclusions

These results show that air sampling of poultry houses in combination with shotgun metagenomics can detect and identify Campylobacter spp. present at low levels. This is important since early detection of Campylobacter in food production can help to decrease the number of food-borne infections.
Gymnasts’ ability to modulate bioelectric sensorimotor rhythms during kinesthetic motor imagery of sports non-specific movements
Authors: Sugino Hirotaka , Ushiyama Junichi
Published: May 2021

Previous psychological studies using questionnaires have consistently reported that athletes have superior motor imagery ability, both for sports-specific and sports non-specific movements. However, regarding motor imagery of sports non-specific movements, no physiological studies have demonstrated differences in neural activity between athletes and non-athletes. The purpose of the present study was to examine differences in bioelectric sensorimotor rhythms during kinesthetic motor imagery (KMI) of sports non-specific movements between gymnasts and non-gymnasts. We selected gymnasts as an example population because they are likely to have particularly superior motor imagery ability due to frequent usage of motor imagery including KMI as part of daily practice. Healthy young participants (16 gymnasts and 16 non-gymnasts) performed repeated motor execution and KMI of sports non-specific movements (wrist dorsiflexion and shoulder abduction of the dominant hand). Scalp electroencephalogram (EEG) was recorded over the contralateral sensorimotor cortex. During motor execution and KMI, sensorimotor EEG power is known to decrease in the α- (8–15 Hz) and β-bands (16–35 Hz), referred to as event-related desynchronization (ERD). We calculated the maximal peak of ERD both in the α- (αERDmax) and β-bands (βERDmax) as a measure of changes in corticospinal excitability. αERDmax was significantly greater in gymnasts, who subjectively evaluated their KMI as being more vivid, for both KMI tasks. On the other hand, βERDmax was greater in gymnasts only for shoulder abduction KMI. These findings suggest gymnasts’ signature of flexibly modulating sensorimotor rhythm with no movements, which may be the basis of their superior ability of KMI for sports non-specific movements.

New & Noteworthy

Kinesthetic motor imagery of sports non-specific movements was compared between gymnasts and non-gymnasts (i.e., healthy controls) from both physiological and psychological approaches. The EEG sensorimotor rhythms during kinesthetic motor imagery were more desynchronized in gymnasts who subjectively imaged their own movements as being more vivid. The work reveals novel ability in gymnasts to flexibly control their sensorimotor rhythms with no actual movements, which would be the basis of their superior ability of motor imagery.
Twenty-one Year Trends for Shorebirds, Waterfowl, and Other Waterbirds at Great Salt Lake, Utah
Authors: Tavernia Brian G. , Meehan Tim , Neill John , Luft John
Published: May 2021

Millions of wetland-dependent birds annually depend on saline lakes and associated wetlands in the western United States. Understanding the population status and trends of birds with different life histories and habitats can guide efforts to secure water resources needed to sustain bird habitats. We used a 21-year dataset to examine population trends for 24 survey units presumed to be high-quality habitat for migratory shorebirds, waterfowl, and other waterbirds at Great Salt Lake and associated wetlands. As expected for high-quality habitats, we found stable or positive trends for 36 of 37 species or groups in fall, spring, or both seasons when considering survey units in aggregate. Despite stable or positive aggregate trends, negative trends did occur in some individual survey units. Foraging, migration distance, and taxonomic groupings were unrelated to trend direction. Research is needed to test whether survey units represent high-quality habitat. With declining regional water resources, stable and positive aggregate trends reinforce the importance of surveyed units at Great Salt Lake and associated wetlands to wetland-dependent birds. Ensuring continuation of stable and positive trends will require identifying environmental factors - including water quantity and quality - driving trends, and require coordinated regional management and monitoring of wetland-dependent birds.
The impact of depressive symptoms on response to integrated cognitive behavioral therapy for substance use disorders and intimate partner violence
Authors: Kelly Lourah M. , Crane Cory A. , Zajac Kristyn , Easton Caroline J.
Published: May 2021

Purpose

Past studies demonstrated the efficacy of integrated cognitive-behavioral therapy (CBT) for substance use disorder (SUD) and intimate partner violence (IPV) as well as high rates of depressive symptoms in this population. However, little is known about how depressive symptoms impact treatment outcomes. The authors hypothesized that integrated CBT, but not standard drug counseling (DC), would buffer the negative effects of depressive symptoms on treatment response.

Design/methodology/approach

A secondary analysis of a randomized trial compared men assigned to 12 weeks of integrated CBT for SUD and IPV (n = 29) to those in DC (n = 34).

Findings

Most (60%) of the sample reported any depressive symptoms. Controlling for baseline IPV, reporting any depressive symptoms was associated with more positive cocaine screens during treatment. Among men with depressive symptoms, integrated CBT but not DC was associated with fewer positive cocaine screens. Controlling for baseline alcohol variables, integrated CBT and depressive symptoms were each associated with less aggression outside of intimate relationships (family, strangers, etc.) during treatment. For men without depressive symptoms, integrated CBT was associated with less non-IPV aggression compared to DC. Effects were not significant for other substances, IPV, or at follow-up.

Research limitations/implications

This study found some evidence for differential response to CBT by depressive symptoms on cocaine and aggression at end of treatment, which did not persist three months later. Future studies should explore mechanisms of integrated CBT for SUD and IPV, including mood regulation, on depressive symptoms in real-world samples.

Practical implications

Integrated CBT buffered depressive symptoms’ impact on cocaine use, yet only improved non-IPV aggression in men without depressive symptoms.

Originality/value

Although integrated CBT’s efficacy for improving SUD and IPV has been established, moderators of treatment response have not been investigated.
Age-inclusive HR practices and the thriving of older workers: the mediating role of occupational future time perspective
Authors: Oliveira Eduardo
Published: May 2021

Purpose

Drawing on social exchange theory and socio-emotional selectivity theory, this paper examines the role of occupational future time perspective (OFTP) in the relationship between age-inclusive HR practices (AIHRP) and the thriving of older workers.

Design/methodology/approach

A two-wave cross-sectional design was adopted with bootstrapped parallel multiple mediation analyses. In addition, polynomial regression with response surface analysis was used to examine the extent to which combinations of focus on opportunities and remaining time relate to thriving at work. Data were collected from 310 older workers working in 13 companies located in Portugal.

Findings

AIHRP have direct effects on OFTP dimensions (i.e. focus on opportunities and remaining time), and indirect effects on the two thriving dimensions (i.e. learning and vitality) via focus on opportunities. The positive relationship between AIHRP and learning was mediated by remaining time, while no significant mediating effect on vitality through remaining time was found. Additionally, surface analysis showed that overall thriving and learning increase more sharply when focus on opportunities is higher than remaining time, rather than vice versa.

Originality/value

This paper contributes to the literature by showing the importance of personal resources like OFTP in the relationship between AIHRP and the thriving of older workers. It also provides further support for the distinctiveness of the two OFTP dimensions as remaining time was not linked to vitality, whereas focus on opportunities was linked to both thriving dimensions.
A new hyperchaotic system from T chaotic system: dynamical analysis, circuit implementation, control and synchronization
Authors: Emiroglu Selcuk , Akgül Akif , Adıyaman Yusuf , Gümüş Talha Enes , Uyaroglu Yılmaz , Yalçın Mehmet Ali
Published: May 2021

Purpose

The purpose of this paper is to develop new four-dimensional (4D) hyperchaotic system by adding another state variable and linear controller to three-dimensional T chaotic dynamical systems. Its dynamical analyses, circuit experiment, control and synchronization applications are presented.

Design/methodology/approach

A new 4D hyperchaotic attractor is achieved through a simulation, circuit experiment and mathematical analysis by obtaining the Lyapunov exponent spectrum, equilibrium, bifurcation, Poincaré maps and power spectrum. Moreover, hardware experimental measurements are performed and obtained results well validate the numerical simulations. Also, the passive control method is presented to make the new 4D hyperchaotic system stable at the zero equilibrium and synchronize the two identical new 4D hyperchaotic system with different initial conditions.

Findings

The passive controllers can stabilize the new 4D chaotic system around equilibrium point and provide the synchronization of new 4D chaotic systems with different initial conditions. The findings from Matlab simulations, circuit design simulations in computer and physical circuit experiment are consistent with each other in terms of comparison.

Originality/value

The 4D hyperchaotic system is presented, and dynamical analysis and numerical simulation of the new hyperchaotic system were firstly carried out. The circuit of new 4D hyperchaotic system is realized, and control and synchronization applications are performed.
Reliability analysis for dependent competing failure of harmonic drive with strength failure and stiffness degradation failure
Authors: Zhang Xian , Jiang Gedong , Zhang Hao , Yun Xialun , Mei Xuesong
Published: May 2021

Purpose

The purpose of this paper is to analyze the dependent competing failure reliability of harmonic drive (HD) with strength failure and degradation failure.

Design/methodology/approach

Based on life tests and stiffness degradation experiments, Wiener process is used to establish the accelerated performance degradation model of HD. Model parameter distribution is estimated by Bayesian inference and Markov Chain Monte Carlo (MCMC) and stiffness degradation failure samples are obtained by a three-step sampling method. Combined with strength failure samples of HD, copula function is used to describe the dependence between strength failure and stiffness degradation failure.

Findings

Strength failure occurred earlier than degradation failure under high level accelerated condition; degradation failure occurred earlier than strength failure under medium- or low-level accelerated condition. Gumbel copula is the optimum copula function for dependence modeling of strength failure and stiffness degradation failure. Dependent competing failure reliability of HD is larger than independent competing failure reliability.

Originality/value

The reliability evaluation method of dependent competing failure of HD with strength failure and degradation failure is first proposed. Performance degradation experiments during accelerated life test (ALT), step-down ALT and life test under rated condition are conducted for Wiener process based step-down accelerated performance degradation modeling.
How social media influencer’s event endorsement changes attitudes of followers: the moderating effect of followers’ gender
Authors: Sun Jie , Leung Xi Yu , Bai Billy
Published: May 2021

Purpose

This paper aims to study how a social media influencer (SMI) endorsement affects followers’ event attitude and behavioral intentions. More importantly, it comparatively examines the role of followers’ gender in event SMI marketing effectiveness.

Design methodology approach

Based on the congruity theory of attitude change, the current study developed an integrated framework of SMI marketing. In total, 335 online surveys were collected. Partial least squares structural equation modeling and multi-group analysis were conducted to test the hypotheses.

Findings

Results show that a follower’s attitude and behavioral intentions toward the event are affected by his or her influencer attitude. The present study also finds that follower’s social media post attitude plays a mediating role. Moreover, female followers are impacted more directly by their influencer attitude, while male followers are affected more indirectly through their attitude toward the social media posts.

Research limitations implications

The current study not only extends the event literature on SMI marketing but also provides recommendations for event professionals on SMI selection.

Originality value

This study examines SMI endorsement as a relatively new marketing tool in the event setting. It also is a pioneer study in testing the effect of social media followers’ gender differences.
Human capital interaction on foreign aid-growth nexus: evidence from South Asia and sub-Saharan Africa
Authors: Nwani Stanley Emife
Published: May 2021

Purpose

The purpose of this study is to examine the interactive role of human capital development (HCD) in foreign aid-growth relations in South Asia and sub-Saharan Africa countries from 1985–2019.

Design/methodology/approach

The study used panel data that cut across all countries in South Asia and sub-Saharan Africa collected from The World Bank’s Development Indicators. The data were analysed using Bai and Ng panel unit root idiosyncratic cross-sectional tests and the system generalised method of moments (SGMM).

Findings

The study found that foreign aid and HCD have negative impacts on economic growth. Fortunately, the interaction of human capital with foreign aid reduces the extent to which foreign aid impedes economic growth. The presumption is that South Asia and sub-Saharan Africa economies had not reaped the potential growth effect of foreign aid inflows due to high illiteracy rates and weak social capacities. The peculiarity of these regions hinders the absorptive capacity to transform positive externality associated with foreign aid into sizeable economic prosperity.

Practical implications

It is imperative for South Asia and sub-Saharan Africa countries to not depend on foreign aid; instead, the strategic action by policymakers should be to developing sustainable social capacities with HCD as the centre-piece.

Originality/value

The highpoint of this study is its inter-regional approach and the interplay between human capital and foreign aid using the second generation panel unit root estimator and the SGMM approaches.
The Islamic credit card as an electronic payment method: the technical trick in the installment payment contract as a financial product
Authors: Alhusban Ahmad Abed Alla , Massadeh Ali Abdel Mahdi , Haloush Haitham
Published: May 2021

Purpose

This study aims to examine the validity of the installment payment contract when using the first Islamic credit card (ICC) in Jordan and will explore the hidden techniques that are used to operate such a financial product. The purpose of the study will be achieved by examining the structure and the issues surrounding the first ICC that was introduced to the Jordanian market as a hybrid contract of Qard Hassan (benevolent loan), Murabaha, Wakalah (agency) and Bay‘ Al Ajjal (credit sale). In addition, a further objective is to examine whether this credit card is a Sharia-compliant financial product.

Design/methodology/approach

A qualitative research method approach was adopted to understand the issues, nature and structure of the first Jordanian ICC. This was due to the explanatory nature of the product, the different financial solutions it offered and the fact that the ICC in Jordan is, to date, relatively unexplored. This paper used the technique of content/thematic analysis that involves multiple sequenced steps to analyze these matters.

Findings

The main finding of this research is that the first ICC in the Jordanian financial market has caused a degree of uncertainty. This is because, once a customer decides to choose the installment payment contract option, the bank does not have real possession of the assets in question. The issue of constructive possession has been denied by several classic and contemporary Islamic scholars, including the General Iftaa Department of Jordan. Therefore, it can be seen that the installment payment contract option does not comply with Islamic principles and particular Fatwas that have been decreed.

Originality/value

This is the first study that shows how the first ICC, being a new Islamic financial product in Jordan, operates in relation to the installment payment contract. In addition, focusing on the concept of changing the nature of the contract from a Qard Hassan (benevolent loan) to a hybrid contract is significant, to encourage Islamic scholars to take a clear, legal stand under Sharia law.
Six sigma in health-care service: a case study on COVID 19 patients’ satisfaction
Authors: Raja Mohamed Kaja Bantha Navas , M. Palaninatha Raja , S. SharmilaParveen , A. John Rajan , Anderson Ranjitham
Published: May 2021

Purpose

The purpose of this paper is to determine the major influencing factors for the COVID 19 patients’ satisfaction with a six sigma framework model and to explore the successful deployment of six sigma in the health-care sector a case study on COVID 19 patients’ satisfaction.

Design/methodology/approach

The study is based on a descriptive research design conducted in Chennai, India between May to July 2020 wherein 1,000 COVID 19 patients were studied. The convenience sampling method is used by the researcher for data collection. In this research paper, define-measure-analysis-improve-control methodology has been applied and factors such as assurance, process standardization, infrastructure, waiting time, cost were analyzed using quality function deployment (QFD), regression analysis and Monte Carlo simulation.

Findings

The applied six sigma model indicated that process standardization contributed the most toward the variation in COVID 19 patients’ satisfaction. Assurance by doctors is the second important factor. The interpersonal quality is important, which indicates a higher level of psychological needs in COVID 19 patients. Waiting time is another important factor influencing COVID 19 patients’ satisfaction. One of the unexpected findings is that cost is insignificant in influencing COVID 19 patients’ satisfaction.

Originality/value

Six Sigma focuses on process variation improvement that encourages data analysis and problem-solving statistical techniques and evaluates the ability of a process to perform defect-free. Six sigma focused toward COVID 19 patients’ satisfaction has not been carried out, which this paper has done.
Custom-made apparel manufacturing micro-enterprise owners’ perspectives on sustainability: how higher education can contribute
Authors: Christie Lorna , Kempen Elizabeth , Strydom Mariette
Published: May 2021

Purpose

The purpose of this paper is to investigate custom-made apparel manufacturing micro-enterprise (CMME) owners’ perspectives of sustainability within their business practices throughout the entire product development process and determine how educational initiatives can promote a more environmentally conscious product development process.

Design/methodology/approach

A qualitative case study, using face-to-face interviews and observations of CMMEs at an incubation hub presents evidence of owners’ sustainability perspectives.

Findings

Although CMME owners disregard sustainability as a pro-environmental approach within the business context, attempts at pro-environmental subconscious behaviour and a deliberate non-environmental consciousness are evident in sourcing and manufacturing during the product development process.

Research limitations/implications

Because of the case study approach of four CMMEs in an IH, the findings may not be applicable to other small and micro-businesses. Despite this limitation, valuable insights emerged that show the current inaptness of the CMMEs to manage an environmentally sustainable business practice.

Social implications

To promote sustainable development goal 12, related to the clothing and textile industry, it is postulated that CMMEs should be supported to minimise their use of resources, thereby promoting environmental sustainability.

Originality/value

The findings of this study direct the development of higher education educational programmes featuring learning content on pro-environmental design and business practices for CMMEs.
Towards effective e-learning on sustainability: a case study-course on participatory processes in environmental politics
Authors: Perbandt Daniela , Heinelt Marie-Sophie , Bacelar-Nicolau Paula , Mapar Mahsa , Caeiro Sandra Sofia
Published: May 2021

Purpose

Distance universities are of great importance for establishing sustainability literacy, as they operate as multipliers for thousands of students. However, despite several advantages of e-learning environments compared to traditional class-teaching, there are still challenges regarding suitable e-learning tools and didactical models. The purpose of this paper is to evaluate the effectiveness of several e-learning tools on students’ knowledge and skills growth and to compare two learning paths, synchronous vs asynchronous, exploring how each affects the level of students’ knowledge achievement and skills acquisition.

Design/methodology/approach

The empirical analysis is based on an online course “Participatory processes in environmental politics”. International MSc and PhD students who enrolled in the course were from FernUniversität in Hagen (Germany) and Aberta University (Portugal). The course was designed as the flipped classroom, applying different e-learning tools and activities, some synchronous and others asynchronous. A pre- and post-evaluation questionnaire was applied to evaluate students’ knowledge and skills. Descriptive statistical analyses were carried out on this data.

Findings

Results showed that in the synchronous group, knowledge about theoretical approaches to citizen participation and sustainable environmental governance improved to a greater extent, whereas the asynchronous group showed greater improvement in nearly all skills related to intercultural communication and e-learning. Also, in the synchronous path, students enhanced their knowledge on “research application” to a greater extent.

Originality/value

Evaluating the effectiveness of different e-learning tools on students’ sustainability knowledge and information and communication technologies skills is a fundamental issue. The study discusses these issues, contributing to enhancing the use of adequate and grounded e-learning models on sustainable development in higher education.
Consumer willingness to pay for locally produced hard cider in the USA
Authors: Jensen Kimberly Lynn , DeLong Karen Lewis , Gill Mackenzie Belen , Hughes David Wheeler
Published: May 2021

Purpose

This study aims to determine whether consumers are willing to pay a premium for locally produced hard apple cider and examine the factors influencing this premium. This study examines the influence of hard apple cider attributes and consumer characteristics on consumer preferences for local hard apple cider.

Design/methodology/approach

Data from a 2019 survey of 875 Tennessee consumers regarding their preferences for a local hard apple cider were obtained. Probit estimates were used to calculate the premium consumers were willing to pay for a locally made hard apple cider and factors influencing this premium. A multivariate probit was used to ascertain factors influencing the importance of attributes (e.g. heirloom apples, sweetness/dryness, sparking/still and no preservatives added) on local hard apple cider preference.

Findings

Consumers would pay a $3.22 premium for local hard apple cider compared with a $6.99 reference product. Local foods preferences, urbanization, weekly purchases of other alcoholic beverages and shopping venues influenced premium amounts. Other important attributes were sweetness/dryness and no preservatives. Influence of consumer demographics suggests targeted marketing of local ciders could be successful.

Originality/value

Few studies examine consumer preferences for hard apple ciders. This study represents a cross-sectional analysis of the premium consumers would pay for local hard apple ciders and the importance of other hard apple cider attributes.
EU money laundering regulation limit the use of tax havens
Authors: Rose Kalle Johannes
Published: May 2021

Purpose

Recent research shows that financial institutions in the European Union (EU) close branches, offices and correspondent connections to jurisdictions with less transparency due to possible sanctions related to the increase in EU money laundering regulation. This tendency is called de-risking and the purpose of this paper is to analyze whether the recent regulatory approach towards money laundering in the EU limits the incentive to have operations in tax havens.

Design/methodology/approach

This paper follows a functional approach to law and economics.

Findings

The paper finds that recent EU money laundering regulation increase an incentive for financial institutions to limit any connection to jurisdictions known as tax havens, where transparency is at minimum. Thereby, it can be discussed whether the spillover effect from money laundering regulation in to the fight of tax avoidance could support further regulatory interference.

Originality/value

The recent trend of de-risking in light of money laundering regulation is scarcely covered by present research. Furthermore, there has been no linking of this de-risking tendency and the effects or relation to the use of tax havens/low tax jurisdictions.
Assessing restaurant review helpfulness through big data: dual-process and social influence theory
Authors: Kwon Wooseok , Lee Minwoo , Back Ki-Joon , Lee Kyung Young
Published: May 2021

Purpose

This study aims to uncover how heuristic information cues (HIC) and systematic information cues (SIC) of online reviews influence review helpfulness and examine a moderating role of social influence in the process of assessing review helpfulness. In particular, this study conceptualizes a theoretical framework based on dual-process and social influence theory (SIT) and empirically tests the proposed hypotheses by analyzing a broad set of actual customer review data.

Design/methodology/approach

For 4,177,377 online reviews posted on Yelp.com from 2004 to 2018, this study used data mining and text analysis to extract independent variables. Zero-inflated negative binomial regression analysis was conducted to test the hypothesized model.

Findings

The present study demonstrates that both HIC and SIC have a significant relationship with review helpfulness. Normative social influence cue (NSIC) strengthened the relationship between HIC and review helpfulness. However, the moderating effect of NSIC was not valid in the relationship between SIC and review helpfulness.

Originality/value

This study contributes to the extant research on review helpfulness by providing a conceptual framework underpinned by dual-process theory and SIT. The study not only identifies determinants of review helpfulness but also reveals how social influences can impact individuals’ judgment on review helpfulness. By offering a state-of-the-art analysis with a vast amount of online reviews, this study contributes to the methodological improvement of further empirical research.