bluuebunny/crossref_metadata_2025 huggingface dataset:
Dual-color GRAB sensors for monitoring spatiotemporal serotonin releasein vivo
Authors: Deng Fei , Wan Jinxia , Li Guochuan , Dong Hui , Xia Xiju , Wang Yipan , Li Xuelin , Zhuang Chaowei , Zheng Yu , Liu Laixin , Yan Yuqi , Feng Jiesi , Zhao Yulin , Xie Hao , Li Yulong
Published: May 2023

The serotonergic system plays important roles in both physiological and pathological processes, and is a widely used therapeutic target for many psychiatric disorders. Although several genetically encoded GFP-based serotonin (5-HT) sensors were recently developed, their sensitivities and spectral profiles are relatively limited. To overcome these limitations, we optimized green fluorescent G-protein-coupled receptor (GPCR)-activation-based 5-HT (GRAB5-HT) sensors and developed a new red fluorescent GRAB5-HTsensor. These sensors have excellent cell surface trafficking, high specificity, sensitivity, and spatiotemporal resolution, making them suitable for monitoring 5-HT dynamicsin vivo. Besides recording subcortical 5-HT release in freely moving mice, we observed both uniform and gradient 5-HT release in the mouse dorsal cortex with mesoscopic imaging. Finally, we performed dual-color imaging and observed seizure-induced waves of 5-HT release throughout the cortex following calcium and endocannabinoid waves. In summary, these 5-HT sensors can offer valuable insights regarding the serotonergic system in both physiological and pathological states.
Does the Wim Hof Method have a beneficial impact on physiological and psychological outcomes in healthy and non-healthy participants? A systematic review
Authors: Almahayni Omar , Hammond Lucy
Published: May 2023

Introduction:Wim Hof, also known as the iceman, developed a method called Wim Hof Method which he claims to have several benefits on physical and mental health. The aim of this systematic review is to identify and synthesise the results of the studies conducted on Wim Hof Method on physiological and psychological health-related outcomes.

Materials and Methods:Medline and Web of Science were searched. Studies were included if they met the predetermined inclusion/exclusion criteria. Data extraction and quality assessment were performed on the included studies. The effects of Wim Hof Method were categorised into physiological or psychological related outcomes and narrative synthesis was conducted.

Results:Nine papers were included in this review which consisted of eight individual trials. The findings of this systematic review suggest that the Wim Hof Method may affect the reduction of inflammation in healthy and non-healthy participants as it increases epinephrine levels, causing an increase in interleukin-10 and a decrease in pro-inflammatory cytokines. Additionally, Wim Hof breathing method was suggested to not enhance the performance of an exercise as minute ventilation, tidal volume, and breathing frequency were statistically insignificant.

Conclusion:Taken together, the findings of this review show promising use of Wim Hof Method in the inflammatory response category. The focus of future studies should move away from investigating the use of Wim Hof breathing method to enhance exercise performance and towards exploring the benefits of Wim Hof Method in non-healthy participants with inflammatory disorders.
Pattern-centric transformation of omics-data sources grounded on multi-wise gene associations aids predictive tasks in TCGA while ensuring interpretability
Authors: Patrício André , Costa Rafael S. , Henriques Rui
Published: May 2023

Motivation

The increasing prevalence of omics data sources is pushing the study of regulatory mechanisms underlying complex diseases such as cancer. However, the vast quantities of features produced and the inherent interplay between them lead to a level of complexity that hampers both descriptive and predictive tasks, requiring custom-built algorithms that can extract relevant information from these sources of data.

Results

We propose a transformation that moves data centered on molecules (e.g. transcripts and proteins) to a new data space focused on putative regulatory modules given by statistically relevant patterns of coexpression. The proposed transformation extracts patterns from the data through biclustering and uses them to create new variables with guarantees of interpretability and discriminative power. The transformation is shown to achieve dimensionality reductions of up to 99% and to increase the predictive performance of various classifiers across multiple omics layers. Our results suggest that a transformation of omics data from gene-centric to pattern-centric data provides benefits to both prediction tasks and human interpretation. The proposed approach is expected to greatly support further bioinformatic analyses for precision medicine applications.

Availability

Software code and the raw results generated are available atgithub.com/Andrempp/Pattern-Centric-Transformation.

Contact

andremppatricio@tecnico.ulisboa.pt

Supplementary information

Supplementary data are available atJournal Nameonline.
Imaging the microscopic viscoelastic anisotropy in living cells
Authors: Keshmiri Hamid , Cikes Domagoj , Samalova Marketa , Schindler Lukas , Appel Lisa-Marie , Urbanek Michal , Yudushkin Ivan , Slade Dea , Weninger Wolfgang J. , Peaucelle Alexis , Penninger Josef , Elsayad Kareem
Published: May 2023

Maintaining and modulating the mechanical anisotropy is essential for biological processes. How this is achieved on the microscopic scale in living soft matter is however not always clear. Here we introduce Brillouin Light Scattering Anisotropy Microscopy (BLAM) for mapping the high-frequency viscoelastic anisotropy inside living cells. Following proof-of-principle experiments on muscle myofibers, we apply this to study two fundamental biological processes. In plant cell walls we show how a phase-transition driven switch between anisotropic-isotropic wall properties may lead to asymmetric growth. In mammalian cell nuclei we uncover a spatio-temporally oscillating elastic anisotropy correlated to chromatin condensation, with long range orientational correlations that may provide a dynamic framework for coordinating intra-nuclear processes. Our results highlight the direct and indirect role the high-frequency mechanics can play in providing dynamic structure that lead to the regulation of diverse fundamental processes in biological systems, and offer a means for studying these. BLAM should find diverse biomedical and material characterization applications.
Fingering instability accelerates population growth of an expanding cell collective
Authors: Ye Yiyang , Lin Jie
Published: May 2023

During the expansion of a cell collective, such as the development of microbial colonies and tumor progression, the local cell growth increases the local pressure, which in turn suppresses cell growth. How this pressure-growth coupling affects the expansion of a cell collective remains unclear. Here, we answer this question using a continuum model of cell collective. We find that a fast-growing leading front and a slow-growing interior of the cell collective emerge due to the pressure-dependent growth rate. The leading front can exhibit fingering instability and we confirm the predicted instability criteria numerically with the leading front explicitly simulated. Intriguingly, we find that fingering instability is not only a consequence of local cell growth but also enhances the entire population’s growth rate as positive feedback. Our work unveils the fitness advantage of fingering formation quantitatively and suggests that the ability to form protrusion can be evolutionarily selected.
Adaptor protein complex 2 in the orbitofrontal cortex predicts alcohol use disorder
Authors: Mulholland Patrick J. , Berto Stefano , Wilmarth Phillip A. , McMahan Christopher , Ball Lauren E. , Woodward John J.
Published: May 2023

Alcohol use disorder (AUD) is a life-threatening disease characterized by compulsive drinking, cognitive deficits, and social impairment that continue despite negative consequences. The inability of individuals with AUD to regulate drinking may involve functional deficits in cortical areas that normally balance actions that have aspects of both reward and risk. Among these, the orbitofrontal cortex (OFC) is critically involved in goal-directed behavior and is thought to maintain a representation of reward value that guides decision making. In the present study, we analyzed post-mortem OFC brain samples collected from age- and sex-matched control subjects and those with AUD using proteomics, bioinformatics, machine learning, and reverse genetics approaches. Of the 4,500+ total unique proteins identified in the proteomics screen, there were 47 proteins that differed significantly by sex that were enriched in processes regulating extracellular matrix and axonal structure. Gene ontology enrichment analysis revealed that proteins differentially expressed in AUD cases were involved in synaptic and mitochondrial function, as well as transmembrane transporter activity. Alcohol-sensitive OFC proteins also mapped to abnormal social behaviors and social interactions. Machine learning analysis of the post-mortem OFC proteome revealed dysregulation of presynaptic (e.g., AP2A1) and mitochondrial proteins that predicted the occurrence and severity of AUD. Using a reverse genetics approach to validate a target protein, we found that prefrontalAp2a1expression significantly correlated with voluntary alcohol drinking in male and female genetically diverse mouse strains. Moreover, recombinant inbred strains that inherited the C57BL/6J allele at theAp2a1interval consumed higher amounts of alcohol than those that inherited the DBA/2J allele. Together, these findings highlight the impact of excessive alcohol consumption on the human OFC proteome and identify important cross-species cortical mechanisms and proteins that control drinking in individuals with AUD.
Consecutive treatments of methamphetamine promote the development of cardiac pathological symptoms in zebrafish
Authors: Zhang Jimmy , Nguyen Anh H. , Jilani Daniel , Torres Ramses Seferino Trigo , Schmiess-Heine Lauren , Le Tai , Xia Xing , Cao Hung
Published: May 2023

Chronic methamphetamine use, a widespread drug epidemic, has been associated with cardiac morphological and electrical remodeling, leading to the development of numerous cardiovascular diseases. While methamphetamine has been documented to induce arrhythmia, most results originate from clinical trials from users who experienced different durations of methamphetamine abuse, providing no documentation on the use of methamphetamine in standardized settings. Additionally, the underlying molecular mechanism on how methamphetamine affects the cardiovascular system remains elusive. A relationship was sought between cardiotoxicity and arrhythmia with associated methamphetamine abuse in zebrafish to identify and to understand the adverse cardiac symptoms associated with methamphetamine. Zebrafish were first treated with methamphetamine 3 times a week over a 2-week duration. Immediately after treatment, zebrafish underwent electrocardiogram (ECG) measurement using an in-house developed acquisition system for electrophysiological analysis. Subsequent analyses of cAMP expression and Ca2+regulation in zebrafish cardiomyocytes were conducted. cAMP is vital to development of myocardial fibrosis and arrhythmia, prominent symptoms in the development of cardiovascular diseases. Ca2+dysregulation is also a factor in inducing arrhythmias. During the first week of treatment, zebrafish that were administered with methamphetamine displayed a decrease in heart rate, which persisted throughout the second week and remained significantly lower than the heart rate of untreated fish. Results also indicate an increased heart rate variability during the early stage of treatment followed by a decrease in the late stage for methamphetamine-treated fish over the duration of the experiment, suggesting a biphasic response to methamphetamine exposure. Methamphetamine-treated fish also exhibited reduced QTc intervals throughout the experiment. Results from the cAMP and Ca2+assays demonstrate that cAMP was upregulated and Ca2+was dysregulated in response to methamphetamine treatment. Collagenic assays indicated significant fibrotic response to methamphetamine treatment. These results provide potential insight into the role of methamphetamine in the development of fibrosis and arrhythmia due to downstream effectors of cAMP.
Asymmetric conformations and lipid interactions shape the ATP-coupled cycle of a heterodimeric ABC transporter
Authors: Tang Qingyu , Sinclair Matt , Hasdemir Hale S. , Stein Richard , Karakas Erkan , Tajkhorshid Emad , Mchaourab Hassane
Published: May 2023

To illuminate the structural origin of catalytic asymmetry of heterodimeric ABC transporters and how it shapes the energetics of their conformational cycles, we used cryo-electron microscopy (cryo-EM), double electron-electron resonance spectroscopy (DEER), and molecular dynamics (MD) simulations, to capture and characterize conformational states of the heterodimeric ABC multidrug exporter BmrCD in lipid nanodiscs. In addition to multiple ATP- and substrate-bound inward-facing (IF) conformations, we obtained the structure of an occluded (OC) conformation wherein the unique extracellular domain (ECD) twists to partially open the extracellular gate. In conjunction with DEER analysis of the populations of these conformations, the structures reveal that ATP-powered isomerization entails changes in the relative symmetry of the BmrC and BmrD subunits that propagates from the transmembrane domain (TMD) to the nucleotide binding domain (NBD). The structures uncover asymmetric substrate and Mg2+binding which we hypothesize are required for triggering ATP hydrolysis preferentially in one of the nucleotide-binding sites. MD simulations demonstrated that multiple lipid molecules, identified from the cryo-EM density maps, differentially bind the IF versus the OC conformation thus modulating their relative stability. In addition to establishing how lipid interactions with BmrCD modulate the energy landscape, our findings are framed in a distinct transport model that highlights the role of asymmetric conformations in the ATP-coupled cycle with implications to the mechanism of ABC transporters in general.
Unveiling Liquid-Crystalline Lipids in the Urothelial Membrane through Cryo-EM
Authors: Yanagisawa Haruaki , Kita Yoshihiro , Oda Toshiyuki , Kikkawa Masahide
Published: May 2023

The urothelium, a distinct epithelial tissue lining the urinary tract, serves as an essential component in preserving urinary tract integrity and thwarting infections. The asymmetric unit membrane (AUM), primarily composed of the uroplakin complex, constitutes a critical permeability barrier in fulfilling this role. However, the molecular architectures of both the AUM and the uroplakin complex have remained enigmatic due to the paucity of high-resolution structural data. In this study, we utilized cryo-electron microscopy to elucidate the three-dimensional structure of the uroplakin complex within the porcine AUM. While the global resolution achieved was 3.5 Å, we acknowledge that due to orientation bias, the resolution in the vertical direction was determined to be 6.3 Å. Our findings unveiled that the uroplakin complexes are situated within hexagonally arranged crystalline lipid membrane domains, rich in hexosylceramides. Moreover, our research rectifies a misconception in a previous model by confirming the existence of a domain initially believed to be absent, and pinpointing the accurate location of a crucialEscherichia colibinding site implicated in urinary tract infections. These discoveries offer valuable insights into the molecular underpinnings governing the permeability barrier function of the urothelium and the orchestrated lipid phase formation within the plasma membrane.
Phase-encoded fMRI tracks down brainstorms of natural language processing with sub-second precision
Authors: Lei Victoria Lai Cheng , Leong Teng Ieng , Leong Cheok Teng , Liu Lili , Choi Chi Un , Sereno Martin I. , Li Defeng , Huang Ruey-Song
Published: May 2023

The human language system interacts with cognitive and sensorimotor regions during natural language processing. However, where, when, and how these processes occur remain unclear. Existing noninvasive subtraction-based neuroimaging techniques cannot simultaneously achieve the spatial and temporal resolutions required to visualize ongoing information flows across the whole brain. Here we have developed phase-encoded designs to fully exploit the temporal information latent in functional magnetic resonance imaging (fMRI) data, as well as overcoming scanner noise and head-motion challenges during overt language tasks. We captured neural information flows as coherent waves traveling over the cortical surface during listening, reciting, and oral cross-language interpreting. The timing, location, direction, and surge of traveling waves, visualized as ‘brainstorms’ on brain ‘weather’ maps, reveal the functional and effective connectivity of the brain in action. These maps uncover the functional neuroanatomy of language perception and production and motivate the construction of finer-grained models of human information processing.
A marker chromosome in psychosis identifies glycine decarboxylase (GLDC) as a novel regulator of neuronal and synaptic function in the hippocampus
Authors: Kambali Maltesh , Li Yan , Unichenko Petr , Pliego Jessica Feria , Yadav Rachita , Liu Jing , McGuinness Patrick , Cobb Johanna G. , Wang Muxiao , Nagarajan Rajasekar , Lyu Jinrui , Vongsouthi Vanessa , Jackson Colin J. , Engin Elif , Coyle Joseph T. , Shin Jeaweon , Talkowski Michael E. , Homanics Gregg E. , Bolshakov Vadim Y. , Henneberger Christian , Rudolph Uwe
Published: May 2023

The biological significance of a small supernumerary marker chromosome that results in dosage alterations to chromosome 9p24.1, including triplication of theGLDCgene encoding glycine decarboxylase, in two patients with psychosis is unclear. In an allelic series of copy number variant mouse models, we identify that triplication ofGldcreduces extracellular glycine levels as determined by optical fluorescence resonance energy transfer (FRET) in dentate gyrus (DG) but not in CA1, suppresses long-term potentiation (LTP) in mPP-DG synapses but not in CA3-CA1 synapses, reduces the activity of biochemical pathways implicated in schizophrenia and mitochondrial bioenergetics, and displays deficits in prepulse inhibition, startle habituation, latent inhibition, working memory, sociability and social preference. Our results thus provide a link between a genomic copy number variation, biochemical, cellular and behavioral phenotypes, and further demonstrate that GLDC negatively regulates long-term synaptic plasticity at specific hippocampal synapses, possibly contributing to the development of neuropsychiatric disorders.
Classifying high-dimensional phenotypes with ensemble learning
Authors: Devine Jay , Kurki Helen K. , Epp Jonathan R. , Gonzalez Paula N. , Claes Peter , Hallgrímsson Benedikt
Published: May 2023

Classification is a fundamental task in biology used to assign members to a class. While linear discriminant functions have long been effective, advances in phenotypic data collection are yielding increasingly high-dimensional datasets with more classes, unequal class covariances, and non-linear distributions. Numerous studies have deployed machine learning techniques to classify such distributions, but they are often restricted to a particular organism, a limited set of algorithms, and/or a specific classification task. In addition, the utility of ensemble learning or the strategic combination of models has not been fully explored.

We performed a meta-analysis of 33 algorithms across 20 datasets containing over 20,000 high-dimensional shape phenotypes using an ensemble learning framework. Both binary (e.g., sex, environment) and multi-class (e.g., species, genotype, population) classification tasks were considered. The ensemble workflow contains functions for preprocessing, training individual learners and ensembles, and model evaluation. We evaluated algorithm performance within and among datasets. Furthermore, we quantified the extent to which various dataset and phenotypic properties impact performance.

We found that discriminant analysis variants and neural networks were the most accurate base learners on average. However, their performance varied substantially between datasets. Ensemble models achieved the highest performance on average, both within and among datasets, increasing average accuracy by up to 3% over the top base learner. Higher class R2values, mean class shape distances, and between– vs. within-class variances were positively associated with performance, whereas higher class covariance distances were negatively associated. Class balance and total sample size were not predictive.

Learning-based classification is a complex task driven by many hyperparameters. We demonstrate that selecting and optimizing an algorithm based on the results of another study is a flawed strategy. Ensemble models instead offer a flexible approach that is data agnostic and exceptionally accurate. By assessing the impact of various dataset and phenotypic properties on classification performance, we also offer potential explanations for variation in performance. Researchers interested in maximizing performance stand to benefit from the simplicity and effectiveness of our approach made accessible via the R packagepheble.
Optimizing Cell Therapy by Sorting Cells with High Extracellular Vesicle Secretion
Authors: Koo Doyeon , Cheng Xiao , Udani Shreya , Zhu Dashuai , Li Junlang , Hall Brian , Tsubamoto Natalie , Hu Shiqi , Ko Jina , Cheng Ke , Di Carlo Dino
Published: May 2023

Critical challenges remain in clinical translation of extracellular vesicle (EV)-based therapeutics due to the absence of methods to enrich cells with high EV secretion. Current cell sorting methods are limited to surface markers that are uncorrelated to EV secretion or therapeutic potential. We developed a nanovial technology for enrichment of millions of single cells based on EV secretion. This approach was applied to select mesenchymal stem cells (MSCs) with high EV secretion as therapeutic cells for improving treatment. The selected MSCs exhibited distinct transcriptional profiles associated with EV biogenesis and vascular regeneration and maintained high levels of EV secretion after sorting and regrowth. In a mouse model of myocardial infarction, treatment with high-secreting MSCs improved heart functions compared to treatment with low-secreting MSCs. These findings highlight the therapeutic importance of EV secretion in regenerative cell therapies and suggest that selecting cells based on EV secretion could enhance therapeutic efficacy.
Hybrid Raman spectroscopy and artificial neural network algorithm discriminatingmycobacterium bovisBCG and members of the ordermycobacteriales
Authors: Macgregor-Fairlie Michael , De Gomes Paulo , Weston Daniel , Rickard Jonathan James Stanley , Goldberg Oppenheimer Pola
Published: May 2023

Even in the face of the COVID-19 pandemic, Tuberculosis (TB) continues to be a major public health problem and the 2nd biggest infectious cause of death worldwide. There is, therefore, an urgent need to develop effective TB diagnostic methods, which are cheap, portable, sensitive and specific. Raman spectroscopy is a potential spectroscopic technique for this purpose, however, so far, research efforts have focused primarily on the characterisation ofMycobacterium tuberculosisand other Mycobacteria, neglecting bacteria within the microbiome and thus, failing to consider the bigger picture. It is paramount to characterise relevant Mycobacteriales and develop suitable analytical tools to discriminate them from each other. Herein, through the combined use of Raman spectroscopy and the self-optimising Kohonen index network and further multivariate tools, we have successfully undertaken the spectral analysis ofMycobacterium bovisBCG,Corynebacterium glutamicumandRhodoccocus erythropolis. This has led to development of a useful tool set, which can readily discern spectral differences between these three closely related bacteria as well as generate a unique spectral barcode for each species. Further optimisation and refinement of the developed method will enable its application to other bacteria inhabiting the microbiome and ultimately lead to advanced diagnostic technologies, which can save many lives.
Glyceroglycolipids are essential forBurkholderia cenocepaciaintracellular survival by preventing phagolysosome acidification
Authors: Shropshire Holly , Guillonneau Richard , Han Zengsheng , Jones Rebekah A. , Ahmed Shadman , García-Romero Inmaculada , Aberdeen Isabel , Nezis Ioannis , Valvano Miguel A. , Scanlan David J. , Chen Yin
Published: May 2023

Burkholderia cenocepaciais a problematic pathogen that infects people with cystic fibrosis and often causes fatal “cepacia syndrome”.B. cenocepaciainfection is difficult to treat due to the high intrinsic resistance of the bacterium to antimicrobials and its ability to survive in macrophages. In this study, we uncover a hitherto unknown aspect ofB. cenocepacia’s pathogenesis related to the formation of new glyceroglycolipids, which is required for intracellular survival. Using lipidomics, we observed thatB. cenocepaciacan produce three glyceroglycolipid species in phosphate deplete conditions using a PlcP-mediated lipid remodelling pathway originally discovered in soil and ocean-dwelling bacteria. While lipid remodelling as an adaptation strategy for environmental microbes to cope with the scarcity of phosphorus is known, its role in intracellular bacterial survival was not investigated. Using mammalian macrophages andGalleria mellonellalarvae as infection models, we showed that the mutant unable to perform membrane lipid remodelling (ΔplcP) could not establish infection. Unlike the wild type bacterium, the ΔplcPmutant did not replicate within macrophages and failed to prevent phagosome acidification. Comparative genomics analyses showed that this PlcP pathway is conserved in all pathogenicBurkholderiathat infect a variety of mammalian and plant hosts. Overall, our results indicate that membrane lipid remodelling plays an essential, yet previously overlooked, role in subverting host immunity.
Aqua{μ-1,4-bis[(1,4,7,10-tetraazacyclododecan-1-yl)methyl]benzene}(nitrato-κO)dicopper(II) tris(nitrate) trihydrate
Authors: Ichimaru Yoshimi , Kato Koichi , Sugiura Kirara , Ogawa Sarina , Jin Wanchun , Kurihara Masaaki , Yamaguchi Yoshihiro , Imai Masanori , Kurosaki Hiromasa
Published: May 2023

In the title dinuclear CuII complex, [Cu2(NO3)(C24H46N8)(H2O)](NO3)3·3H2O, the two CuII molecules both have a square-pyramidal geometry, but the ligands in the axial positions are different: a water molecule and a nitrate ion. All nitrate ions, water molecules, and N—H groups are involved in an intermolecular hydrogen-bond network.
The effects of team diversity on promoting sustainable luxury products
Authors: Quach Sara , Septianto Felix , Thaichon Park , Sung Billy
Published: May 2023

Purpose

This research examines the effect of team diversity on customer behavior (purchase likelihood) associated with sustainable luxury products and further considers the mediating role of customer skepticism and the moderating role of the growth mindset in these relationships.

Design/methodology/approach

Study 1 aims to confirm the direct effect of team diversity on purchase intention and the mediating effect of customer skepticism. Featuring a fictitious brand, Study 2 seeks to test the moderating effects of a growth mindset. This research recruits participants located in the USA who have shopping experiences with a luxury product.

Findings

The findings support the notion that team diversity can mitigate customers' skepticism while enhancing purchase likelihood. Moreover, this effect is stronger among those with a growth mindset. As such, the findings suggest that communicating the heterogeneous composition of team members can benefit sustainable luxury brands.

Originality/value

Underpinned by the signaling theory and incremental theory, this research examines the effects of team diversity on customer behavior (purchase likelihood) related to sustainable luxury products, as well as the role of customer skepticism (as a mediator) and a growth mindset (as a moderator) in these relationships. Thus, the findings broaden the current diversity research which has predominantly focused on team decision-making and performance.
The effect of corruption level in steering the business–government relations: evidence from 23 African countries
Authors: Tesfagebreal Mebrahtu , Chang Li , Tuo Siele Jean , Qian Yu
Published: May 2023

Purpose

The purpose of this paper is to investigate the effect of corruption level in steering the business–government relations (BGRs) in developing countries. It also examines the moderating effect of firm size.

Design/methodology/approach

Using robust tobit and probit models, this study tests the response behavior of 9787 firms from 23 African countries to their government's policy and regulations and the direct effect of corruption control level in their response decisions. The authors also perform several other additional analyses to ensure the robustness of the findings, including change analysis, two-stage model and recursive bivariate model.

Findings

The result shows that corruption level is among the significant factors that drive BGRs exponentially. The finding points out that, there is a strong alliance of business and government in more corrupt countries. Moreover, the impact of corruption level exacerbates when the firm is bigger.

Research limitations/implications

Managers should focus more on activities that create long-term sustainable advantage. Valuable time of the senior managers should not waste on negotiating government policies to earn a short term advantages.

Practical implications

It is evident that legal and transparent government alliances can lead to economic rent for firms. However, it is important to note that any alliance based on corruption and illegality is short-lived and ultimately detrimental to long-term prosperity. Therefore, it is crucial for firms to prioritize ethical business practices and build relationships with governments that prioritize transparency and accountability.

Social implications

Given the detrimental impact of corruption on economic progress, it is crucial for Africa policy-makers to prioritize reforms aimed at reducing its adverse effect. By implementing ethical and transparent business practices, countries can attract more investment and promote economic growth.

Originality/value

This study contributes to the existing literature on the passive form of political connectivity/activity and to what extend corruption level affect the political activities of firms.
Enhancing supply chain resilience in SMEs: the role of business and political ties
Authors: Alghababsheh Mohammad
Published: May 2023

Purpose

The COVID-19 pandemic outbreak has created disruptions across the supply chain that are beyond the resources of small and medium-sized enterprises (SMEs) to effectively deal with. This study aims to examine the idea that top managers' business and political ties can play direct roles in enhancing SCR in SMEs during COVID-19 by providing access to valuable resources. The study further investigates integrative capability as an underlying mechanism through which the effects of business and political ties can be transformed into enhanced SCR.

Design/methodology/approach

Responses from 217 SMEs in the country of Jordan were received via an online survey. The measurement and structural models were tested using the partial least squares structural equation modelling (PLS-SEM) technique.

Findings

The study found that business and political ties are positively related to SCR. However, integrative capability fully mediates the relationship between business ties and SCR, whereas it partially mediates the relationship between political ties and SCR.

Research limitations/implications

The study examined only the direct and indirect impacts of business and political ties on SCR. It could be extended by exploring the conditions under which they influence SCR.

Originality/value

The study explicates the role of top managers' business and political ties on improving SCR in a developing country context. It further examines the mediating role of integrative capability in the relationships between business and political ties and SCR.
Multi-fidelity surrogate-based optimization for microfluidic concentration gradient generator design
Authors: Yang Haizhou , Hong Seong Hyeon , Qian Yu , Wang Yi
Published: May 2023

Purpose

This paper aims to present a multi-fidelity surrogate-based optimization (MFSBO) method for computationally accurate and efficient design of microfluidic concentration gradient generators (µCGGs).

Design/methodology/approach

Cokriging-based multi-fidelity surrogate model (MFSM) is constructed to combine data with varying fidelities and computational costs to accelerate the optimization process and improve design accuracy. An adaptive sampling approach based on parallel infill of multiple low-fidelity (LF) samples without notably adding computation burden is developed. The proposed optimization framework is compared with a surrogate-based optimization (SBO) method that relies on data from a single source, and a conventional multi-fidelity adaptive sampling and optimization method in terms of the convergence rate and design accuracy.

Findings

The results demonstrate that proposed MFSBO method allows faster convergence and better designs than SBO for all case studies with 49% more reduction in the objective function value on average. It is also found that parallel infill (MFSBO-4) with four LF samples, enables more robust, efficient and accurate designs than conventional multi-fidelity infill (MFSBO-1) that only adopts one LF sample during each iteration for more complex optimization problems.

Originality/value

A MFSM based on cokriging method is constructed to utilize data with varying fidelities, accuracies and computational costs for µCGG design. A parallel infill strategy based on multiple infill criteria is developed to accelerate the convergence and improve the design accuracy of optimization. The proposed methodology is proved to be a feasible method for µCGG design and its computational efficiency is verified.
Dynamic response of damaged rigid-frame bridges subjected to moving loads using analytical based formulations
Authors: Bozyigit Baran
Published: May 2023

Purpose

This study aims to perform dynamic response analysis of damaged rigid-frame bridges under multiple moving loads using analytical based transfer matrix method (TMM). The effects of crack depth, moving load velocity and damping on the dynamic response of the model are discussed. The dynamic amplifications are investigated for various damage scenarios in addition to displacement time-histories.

Design/methodology/approach

Timoshenko beam theory (TBT) and Rayleigh-Love bar theory (RLBT) are used for bending and axial vibrations, respectively. The cracks are modeled using rotational and extensional springs. The structure is simplified into an equivalent single degree of freedom (SDOF) system using exact mode shapes to perform forced vibration analysis according to moving load convoy.

Findings

The results are compared to experimental data from literature for different damaged beam under moving load scenarios where a good agreement is observed. The proposed approach is also verified using the results from previous studies for free vibration analysis of cracked frames as well as dynamic response of cracked beams subjected to moving load. The importance of using TBT and RLBT instead of Euler–Bernoulli beam theory (EBT) and classical bar theory (CBT) is revealed. The results show that peak dynamic response at mid-span of the beam is more sensitive to crack length when compared to moving load velocity and damping properties.

Originality/value

The combination of TMM and modal superposition is presented for dynamic response analysis of damaged rigid-frame bridges subjected to moving convoy loading. The effectiveness of transfer matrix formulations for the free vibration analysis of this model shows that proposed approach may be extended to free and forced vibration analysis of more complicated structures such as rigid-frame bridges supported by piles and having multiple cracks.
The “industrial halo” and its impact on the assessment of corporate reputation
Authors: Calvo-Iriarte Emilio , Esteban-González María Victoria , Rodríguez-Castellanos Arturo
Published: May 2023

Purpose

The gap that this research attempts to fill is to analyse the explanatory factor “industry” when assessing the reputation of a corporate group. In other words, this research attempts to demonstrate the impact of the “industrial halo” on the assessment of corporate reputation, given that, to date, the academic literature has not considered industry as an explanatory variable in the assessment of the reputation of private companies.

Design/methodology/approach

A sample of 43 Spanish companies was used to analyse the relationship between the reputation of firms as measured by the Merco Empresas index, and the industries to which they belong, after controlling for company performance, size, turnover, public recognition of their leadership, and corporate responsibility. This involved conducting a cross-sectional analysis of the relationship between the variables for each year in the time period from 2005 to 2016. The available data were taken from the firms' annual financial reports and websites, as well as from the Merco.

Findings

The paper shows the existence of industrial halos that account for the corporate reputation of businesses in Spain. It is also shown that industrial halos are not permanent over time, and that they tend to occur in years of crisis.

Research limitations/implications

It would have been desirable for this study to have had sufficient data to include other industries, but this was not possible. As for possible extensions, in addition to expanding the period considered, other analytical techniques, such as panel data models, could be applied to allow comparison with the results obtained here.

Practical and social implications

The results of this study have some practical implications. Firstly, firms that publish corporate reputation rankings should be aware of the distortion that the industrial halo can produce, especially in times of uncertainty, and seek to correct for it in their measurements. And secondly, corporate groups themselves should assume that the reputation of the industry affects their individual reputation, and consequently, they should see the other companies in the industry not only as competitors but also as “reputational allies”. They should therefore make collective efforts to improve in this respect, especially in the face of reputational crises.

Originality/value

This paper provides a better understanding of the relationship between the reputation of a company and the industry to which it belongs, and of its permanence over time. This relationship has been little studied in the Spanish market to date.
The impacts of the cyber-trust program on the cybersecurity maturity of government entities in the Kingdom of Bahrain
Authors: Shaheen Khalid , Zolait Ali Hussein
Published: May 2023

Purpose

This study aims to determine the impacts of the Bahrain Government framework [cyber-trust program (CTP)] on the cybersecurity maturity of government entities and how the CTP can impact the cybersecurity of government entities in the Kingdom of Bahrain.

Design/methodology/approach

The authors used a quantitative and qualitative approach. The data were collected by conducting semi-structured interviews with the information technology experts in the Bahrain Government entities participating in the CTP. Also, quantitative data was obtained through a questionnaire distributed to relevant people in the information technology field.

Findings

The findings of this study suggest that the CTP had a significant impact on the cybersecurity assurance of the government entities that participated in the CTP; it increased the employees’ awareness, reduced the number of cyberattacks and optimized the available resources. The findings also highlighted the role of top management in the success of the implementation of the CTP. The results also ensure that the CTP’s maturity model affected the cybersecurity compliance of an organization and the implementation of cybersecurity policies and controls.

Practical implications

This study enhances cybersecurity researchers’ and practitioners’ understanding of the impact of the CTP and its components and evaluates its influence on Bahrain’s cybersecurity assurance.

Originality/value

This study implies that to achieve better cybersecurity, managers should focus on implementing the policies and controls provided by cybersecurity frameworks to enhance cybersecurity assurance.
Corporate fraud and industry peer effects on IPO underpricing
Authors: Palkar Darshana
Published: May 2023

Purpose

Existing studies suggest that negative impacts emanating from corporate fraud revelations may diffuse to other firms through lower trust and lower market participation. Extending this literature stream, the authors examine whether corporate fraud revelations are associated with higher costs of raising capital through initial public offerings (IPOs) for industry peers.

Design/methodology/approach

The authors employ several analysis techniques including univariate analysis, multivariate regressions, propensity score matching methodology, and probit estimation. The sample consists of 3,015 US IPO firms for the 1996–2021 period.

Findings

By adopting US private securities class action lawsuits as a proxy for the presence of corporate fraud, the authors find that fraud revelations are associated with higher IPO underpricing, higher post-IPO stock return volatility and increased likelihood of withdrawal from the offering for industry peers. The findings are robust to alternative industry definitions and litigation proxies and to the inclusion of a battery of controls, including industry, state and year fixed effects.

Originality/value

This study presents private firms with an additional industry litigation factor to consider when assessing the marginal costs of going public.
Supervisor support, religiosity, work engagement, and affective commitment: evidence from a Middle Eastern emerging market
Authors: Abualigah Ahmad , Darwish Tamer K. , Davies Julie , Haq Muhibul , Ahmad Syed Zamberi
Published: May 2023

Purpose

Drawing on job demands-resources (JD-R) theory, this study aims to develop a model of how work engagement mediates the relationship between supervisor support and affective commitment, with religiosity moderating the relationship between supervisor support and work engagement. This study further tests a moderated-mediation model exploring the relationships between supervisor support, religiosity, work engagement and affective commitment within a unique institutional context where religious values and beliefs significantly influence and shape people management practices.

Design/methodology/approach

Using a survey-based approach, data were collected from 367 employees from the telecommunication sector in the context of Jordan.

Findings

Supervisor support was positively related to work engagement, which positively impacts affective commitment. Work engagement mediated the relationship between supervisor support and affective commitment. In addition, religiosity amplified the relationship between supervisor support and work engagement, and the mediating effect of work engagement on the relationship between supervisor support and affective commitment.

Originality/value

This study contributes to JD-R theory and pertinent literature by examining the moderating role of religiosity, an important yet neglected personal resource. To the best of the authors’ knowledge, this study is the first to examine the interaction effect between religiosity and supervisor support in predicting work engagement. It is also the first to examine a moderated mediation model exploring the relationships between supervisor support, religiosity, work engagement and affective commitment.
Analysis of factors influencing USA households' choice of ethnic restaurants
Authors: Bakhtavoryan Rafael , Suchini Chrystian , Lopez Jose , Djidonou Desire
Published: May 2023

Purpose

This study empirically identifies household demographic and socioeconomic characteristics as well as restaurant characteristics that affect the probability of households choosing an ethnic restaurant (American, Asian, European, Mexican and other) in the USA.

Design/methodology/approach

A multinomial logistic regression model is applied using the data derived from the information from the National Household Food Acquisition and Purchase Survey conducted between April 2012 and January 2013.

Findings

The empirical findings suggest that such factors as the unit cost on away-from-home food items (i.e. price), region of residence, primary respondent's ethnicity, race, education level, marital status and employment status as well as such restaurant characteristics as availability of loyalty program and presence of coupons significantly affect the probability of households choosing a particular ethnic restaurant in the USA.

Research limitations/implications

The original dataset employed in this study does not permit the quantification of information associated with size, location, and number of years in operation for the ethnic restaurants considered. Also, the dataset does not permit the classification of the ethnic restaurants included in the “other” category.

Originality/value

To the best of the authors' knowledge, there has been no empirical micro-level analysis associated with determining factors impacting households' choice of ethnic restaurants using a polytomous logistic regression model allowing for a wide range of ethnic restaurants and covering the entire USA, based on an extensive set of household demographic and socioeconomic factors and restaurants characteristics. As such, the current study plugs this research gap, with the empirical findings furnished by this study being of importance to ethnic restaurant operators (owners) in the operators' effort to develop effective marketing strategies.