bluuebunny/crossref_metadata_2025 huggingface dataset:
Neurodegeneration and neuroinflammation are linked, but independent ofα-synuclein inclusions, in a seeding/spreading mouse model of Parkinson’s disease
Authors: Garcia Pierre , Jürgens-Wemheuer Wiebke , Uriarte Oihane , Schmit Kristopher J , Masuch Annette , Brioschi Simone , Weihofen Andreas , Koncina Eric , Coowar Djalil , Heurtaux Tony , Glaab Enrico , Balling Rudi , Sousa Carole , Michelucci Alessandro , Kaoma Tony , Nicot Nathalie , Pfander Tatjana , Schulz-Schaeffer Walter , Allouche Ahmad , Fischer Nicolas , Biber Knut , Mittelbronn Michel , Buttini Manuel
Published: August 2020

A key process of neurodegeneration in Parkinson’s disease (PD) is the transneuronal spreading of α-synuclein. Alpha-synuclein is a presynaptic protein that is implicated in the pathogenesis of PD and other synucleinopathies, where it forms, upon intracellular aggregation, pathological inclusions. Other hallmarks of PD include neurodegeneration and microgliosis in susceptible brain regions. Whether it is primarily transneuronal spreading of α-synuclein particles, inclusion formation, or other mechanisms, such as inflammation, that cause neurodegeneration in PD is unclear. We used spreading/aggregation of α-synuclein induced by intracerebral injection of α-synuclein preformed fibrils into the mouse brain to address this question. We performed quantitative histological analysis for α-synuclein inclusions, neurodegeneration, and microgliosis in different brain regions, and a gene expression profiling of the ventral midbrain, at two different timepoints after disease induction. We observed significant neurodegeneration and microgliosis in brain regions not only with, but also without α-synuclein inclusions. We also observed prominent microgliosis in injured brain regions that did not correlate with neurodegeneration nor with inclusion load. In longitudinal gene expression profiling experiments, we observed early and unique alterations linked to microglial mediated inflammation that preceded neurodegeneration, indicating an active role of microglia in inducing neurodegeneration. Our observations indicate that α-synuclein inclusion formation is not the major driver in the early phases of PD-like neurodegeneration, but that diffusible, oligomeric α-synuclein species, which induce unusual microglial reactivity, play a key role in this process. Our findings uncover new features of α-synuclein induced pathologies, in particular microgliosis, and point to the necessity of a broader view of the process of “prion-like spreading” of that protein.
Osmolarity-independent electrical cues guide rapid response to injury in zebrafish epidermis
Authors: Kennard Andrew S. , Theriot Julie A.
Published: August 2020

The ability of epithelial tissues to heal after injury is essential for animal life, yet the mechanisms by which epithelial cells sense tissue damage are incompletely understood. In aquatic organisms such as zebrafish, osmotic shock following injury is believed to be an early and potent activator of a wound response. We find that, in addition to sensing osmolarity, basal skin cells in zebrafish larvae are also sensitive to changes in the particular ionic composition of their surroundings after wounding, specifically the concentration of sodium chloride in the immediate vicinity of the wound. This sodium chloride-specific wound detection mechanism is independent of cell swelling, and instead is suggestive of a mechanism by which cells sense changes in the transepithelial electrical potential generated by the transport of sodium and chloride ions across the skin. Consistent with this hypothesis, we show that electric fields directly applied within the skin are sufficient to initiate actin polarization and migration of basal cells in their native epithelial contextin vivo, even overriding endogenous wound signaling. This suggests that, in order to mount a robust wound response, skin cells respond to both osmotic and electrical perturbations arising from tissue injury.
Rapid GMP-compliant expansion of SARS-CoV-2-specific T cells from convalescent donors for use as an allogeneic cell therapy for COVID-19
Authors: Cooper Rachel S , Fraser Alasdair R , Smith Linda , Burgoyne Paul , Imlach Stuart N , Jarvis Lisa M , Zahra Sharon , Turner Marc L. , Campbell John DM
Published: August 2020

COVID-19 disease caused by the SARS-CoV-2 virus is characterized by dysregulation of effector T cells and accumulation of exhausted T cells. T cell responses to viruses can be corrected by adoptive cellular therapy using donor-derived virus-specific T cells. Here we show that SARS-CoV-2-exposed blood donations contain CD4 and CD8 memory T cells specific for SARS-CoV-2 spike, nucleocapsid and membrane antigens. These peptides can be used to isolate virus-specific T cells in a GMP-compliant process. These T cells can be rapidly expanded using GMP-compliant reagents for use as a therapeutic product. Memory and effector phenotypes are present in the selected virus-specific T cells, but our method rapidly expands the desirable central memory phenotype. A manufacturing yield ranging from 1010to 1011T cells can be obtained within 21 days culture. Thus, multiple therapeutic doses of virus-specific T cells can be rapidly generated from convalescent donors for treatment of COVID-19 patients

One Sentence Summary

CD4+ and CD8+ T cells specific for SARS-CoV-2 can be isolated from convalescent donors and rapidly expanded to therapeutic doses at GMP standard, maintaining the desired central memory phenotype required for protective immune responses against severe COVID-19 infections.
Cortical silencing results in paradoxical fMRI overconnectivity
Authors: Canella Carola , Rocchi Federico , Noei Shahryar , Gutierrez-Barragan Daniel , Coletta Ludovico , Galbusera Alberto , Vassanelli Stefano , Pasqualetti Massimo , Iurilli Giuliano , Panzeri Stefano , Gozzi Alessandro
Published: August 2020

fMRI-based measurements of functional connectivity are commonly interpreted as an index of anatomical coupling and direct interareal communication. However, causal testing of this hypothesis has been lacking. Here we combine neural silencing, resting-state fMRI andin vivoelectrophysiology to causally probe how inactivation of a cortical region affects brain-wide functional coupling. We find that chronic silencing of the prefrontal cortex (PFC) via overexpression of a potassium channel paradoxically increases rsfMRI connectivity between the silenced area and its thalamo-cortical terminals. Acute chemogenetic silencing of the PFC reproduces analogous patterns of overconnectivity, an effect associated with over-synchronous fMRI coupling between polymodal thalamic regions and widespread cortical districts. Notably, multielectrode recordings revealed that chemogenetic inactivation of the PFC attenuates gamma activity and increases delta power in the silenced area, resulting in robustly increased delta band coherence between functionally overconnected regions. The observation of enhanced rsfMRI coupling between chemogenetically silenced areas challenges prevailing interpretations of functional connectivity as a monotonic index of direct axonal communication, and points at a critical contribution of slow rhythm generators to the establishment of brain-wide functional coupling.
Liquid-liquid phase separation of tau driven by hydrophobic interaction facilitates fibrillization of tau
Authors: Lin Yanxian , Fichou Yann , Longhini Andrew P. , Llanes Luana C. , Yin Yinson , Bazan Guillermo C. , Kosik Kenneth S. , Han Songi
Published: August 2020

Amyloid aggregation of tau protein is implicated in neurodegenerative diseases, yet its facilitating factors are poorly understood. Recently, tau has been shown to undergo liquid liquid phase separation (LLPS) bothin vivoandin vitro. LLPS was shown to facilitate tau amyloid aggregation in certain cases, while independent of aggregation in other cases. It is therefore important to understand the differentiating properties that resolve this apparent conflict. We report on a model system of hydrophobically driven LLPS induced by high salt concentration (LLPS-HS), and compare it to electrostatically driven LLPS represented by tau-RNA/heparin complex coacervation (LLPS-ED). We show that LLPS-HS promotes tau protein dehydration, undergoes maturation and directly leads to canonical tau fibrils, while LLPS-ED is reversible, remains hydrated and does not promote amyloid aggregation. We show that the nature of the interaction driving tau condensation is the differentiating factor between aggregation-prone and aggregation-independent LLPS.
A Facile Method for Simultaneous Visualization of Wet Cells and Nanostructured Biomaterials in SEM using Ionic Liquids
Authors: Lee Bryan E.J. , DiCecco Liza-Anastasia , Exir Hourieh , Weck Arnaud , Sask Kyla , Grandfield Kathryn
Published: August 2020

This work presents a successful methodology to image mammalian cells adhered to nanostructured biomaterials using scanning electron microscopy (SEM) operating in low-vacuum mode following ionic liquid treatment. Human osteoblast-like Saos-2 cells were treated with a room-temperature ionic liquid, 1-Ethyl-3-methylimidazolium tetrafluoroborate, and subsequently imaged on titanium utilizing SEM. Titanium substrates were modified to create laser-induced periodic surface structures (LIPSS) for visualizing at the sub-micron scale. Using a combination of fluorescence-based cell metabolism along with light microscopy and SEM image analysis, the shape and location of irradiated cells were confirmed to be unchanged after multiple irradiation sessions while the viability of minimally irradiated cells was unaltered. The wet imaging conditions combined with a rapid facile protocol using ionic liquid allows this technique to fulfill a niche in examining cellular behavior on biomaterials with sub-micron surface features. The demonstrated method to track observed cell adhesion to sub-micron surface features with SEM has great implications for the understanding of cell migration on nanostructured surfaces as well as on the exploration of simpler SEM preparation methods for cellular imaging.
The antimicrobial activity of the macrophage metabolite itaconate is synergistic with acidity
Authors: Duncan Dustin , Lupien Andréanne , Behr Marcel A. , Auclair Karine
Published: August 2020

The production of itaconate by macrophages was only discovered in 2011. A rapidly increasing number of studies have since revealed essential biological roles for itaconate, ranging from antimicrobial to immunomodulator. Itaconate has been estimated to reach low-millimolar concentrations in activated macrophages, including those within infected lungs and brains, whereas itaconate’s MIC towards several bacterial strains were measured to be in the low-to-mid-millimolar range, casting some doubts on the antibacterial role of itaconatein vivo. Several of these investigations, in particular those measuring MIC values of itaconate or itaconic acid, have however tended to ignore the high acidity of this small diacid (pKas 3.85 and 5.45), thereby potentially biasing the MIC measurements. We report herein that: 1) at high concentration, itaconic acid can significantly reduce the pH of growth media; 2) the antibacterial activity of itaconate increases in a synergistic manner with acidity; 3) this synergistic effect is not simply due to increased permeability of monoanionic itaconate; 4) considering that the MIC of itaconate is many fold lower under acidic conditions for all strains tested, itaconate may serve an antimicrobial role, particularly in acidic vesicles such as the phagolysosome; and 5) differential growth behavior in the presence of disodium itaconate versus itaconic acid may serve to rapidly screen bacterial strains for their ability to metabolize itaconate. Our results further support the hypothesis that inhibitors of itaconate degradation in bacteria may provide a new strategy to treat infections.
IFN-γand TNF-αdrive aCXCL10+CCL2+ macrophage phenotype expanded in severe COVID-19 and other diseases with tissue inflammation
Authors: Zhang Fan , Mears Joseph R. , Shakib Lorien , Beynor Jessica I. , Shanaj Sara , Korsunsky Ilya , Nathan Aparna ,   Accelerating Medicines Partnership Rheumatoid Arthritis and Systemic Lupus Erythematosus (AMP RA/SLE) Consortium, Donlin Laura T. , Raychaudhuri Soumya
Published: August 2020

Immunosuppressive and anti-cytokine treatment may have a protective effect for patients with COVID-19. Understanding the immune cell states shared between COVID-19 and other inflammatory diseases with established therapies may help nominate immunomodulatory therapies. Using an integrative strategy, we built a reference by meta-analyzing > 300,000 immune cells from COVID-19 and 5 inflammatory diseases including rheumatoid arthritis (RA), Crohn’s disease (CD), ulcerative colitis (UC), lupus, and interstitial lung disease. Our cross-disease analysis revealed that anFCN1+ inflammatory macrophage state is common to COVID-19 bronchoalveolar lavage samples, RA synovium, CD ileum, and UC colon. We also observed that aCXCL10+CCL2+ inflammatory macrophage state is abundant in severe COVID-19, inflamed CD and RA, and expresses inflammatory genes such asGBP1, STAT1, andIL1B. We found that theCXCL10+CCL2+ macrophages are transcriptionally similar to blood-derived macrophages stimulated with TNF-αand IFN-γ ex vivo. Our findings suggest that IFN-γ, alongside TNF-α, might be a key driver of this abundant inflammatory macrophage phenotype in severe COVID-19 and other inflammatory diseases, which may be targeted by existing immunomodulatory therapies.
The DHODH Inhibitor PTC299 Arrests SARS-CoV-2 Replication and Suppresses Induction of Inflammatory Cytokines
Authors: Luban Jeremy , Sattler Rachel , Mühlberger Elke , Graci Jason D. , Cao Liangxian , Weetall Marla , Trotta Christopher , Colacino Joseph M. , Bavari Sina , Strambio-De-Castillia Caterina , Suder Ellen L. , Wang Yetao , Soloveva Veronica , Cintron-Lue Katherine , Naryshkin Nikolai A. , Pykett Mark , Welch Ellen M. , O’Keefe Kylie , Kong Ronald , Goodwin Elizabeth , Jacobson Allan , Paessler Slobodan , Peltz Stuart
Published: August 2020

The coronavirus disease 2019 (COVID-19) pandemic has created an urgent need for therapeutics that inhibit the SARS-CoV-2 virus and suppress the fulminant inflammation characteristic of advanced illness. Here, we describe the anti-COVID-19 potential of PTC299, an orally available compound that is a potent inhibitor of dihydroorotate dehydrogenase (DHODH), the rate-limiting enzyme of the de novo pyrimidine biosynthesis pathway. In tissue culture, PTC299 manifests robust, dose-dependent, and DHODH-dependent inhibition of SARS CoV-2 replication (EC50range, 2.0 to 31.6 nM) with a selectivity index >3,800. PTC299 also blocked replication of other RNA viruses, including Ebola virus. Consistent with known DHODH requirements for immunomodulatory cytokine production, PTC299 inhibited the production of interleukin (IL)-6, IL-17A (also called IL-17), IL-17F, and vascular endothelial growth factor (VEGF) in tissue culture models. The combination of anti-SARS-CoV-2 activity, cytokine inhibitory activity, and previously established favorable pharmacokinetic and human safety profiles render PTC299 a promising therapeutic for COVID-19.
Analysis of the potential impact of genomic variants in SARS-CoV-2 genomes from India on molecular diagnostic assays
Authors: Jain Abhinav , Rophina Mercy , Mahajan Saurabh , Krishnan Bhavya Balaji , Sharma Manasa , Mandal Sreya , Fernandez Teresa , Sultanji Sumayra , Mathew Samatha , Sivasubbu Sridhar , Scaria Vinod
Published: August 2020

An isolated epidemic of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) causing Coronavirus Diseases (COVID-19) originating in Wuhan, China has now rapidly emerged into a global pandemic affecting millions of people worldwide. Molecular detection of SARS-CoV-2 using reverse transcription polymerase chain reaction (RT-PCR) forms the mainstay in screening, diagnosis and epidemiology of disease. The virus has been evolving through base substitutions. The recent availability of genomes of SARS-CoV-2 isolates from different countries including India motivated us to assess the presence and potential impact of variations in target sites for the oligonucleotide primers and probes used in molecular diagnosis. We catalogued a total of 132 primers or probes sequences from the literature and the public domain. Our analysis revealed a total of 125 unique genetic variants in 80 either primers or probes binding sites. A total of 13 unique variants had allele frequency of ≥ 1% in Indian SARS-CoV-2 genomes mapped to the primers or probes binding sites. A total of 15 primers or probes binding sites had cumulative variant frequency of ≥ 1% in the SARS-CoV-2 genomes. These included primers or probes sites which are widely used in India and across the world for molecular diagnosis as well as approved by national and international agencies. This highlights the need for sequencing genomes of emerging pathogens to make evidence based policies for development and approval of diagnostics. To the best of our knowledge, ours is the most comprehensive analysis of genomic variants in genomes of SARS-CoV-2 isolates from India and their potential impact on efficacy of molecular diagnostics.
Dynamic patterns of correlated activity in the prefrontal cortex encode information about social behavior
Authors: Frost Nicholas A. , Haggart Anna , Sohal Vikaas S.
Published: August 2020

New technologies have made it possible to measure activity from many neurons simultaneously. Nevertheless, most studies still analyze the activity of simultaneously recorded neurons one-at-a-time, then group together neurons which increase their activity during similar behaviors into an ‘ensemble.’ This notion of an ensemble ignores the ability of neurons to act collectively, and encode and transmit information in ways that are not reflected by their individual activity levels. We used microendoscopic GCaMP imaging to measure prefrontal activity while mice were either alone or engaged in social interaction. We developed new approaches, using neural network classifiers and surrogate (shuffled) datasets, to characterize how neurons synergistically transmit information about social behavior. Surrogate datasets which preserve behaviorally-specific patterns of coactivity (correlations) outperform those which preserve behaviorally-driven changes in activity levels but not correlated activity. This shows that prefrontal neurons act collectively to transmit information about socialization, because social behavior elicits increases in correlated activity that are not explained simply by the activity levels of the underlying neurons. Notably, this ability of correlated activity to enhance the information transmitted by neuronal ensembles is lost in mice lacking the autism-associated gene Shank3. These results show that synergy is an important concept for the coding of social behavior which can be disrupted in disease states, reveal a specific mechanism underlying this synergy (social behavior increases correlated activity within specific ensembles), and outlines methods for studying how neurons within an ensemble can work together to encode information.
Disruption of innate defense responses by endoglycosidase HPSE promotes cell survival
Authors: Agelidis Alex , Turturice Benjamin A. , Suryawanshi Rahul K. , Yadavalli Tejabhiram , Jaishankar Dinesh , Ames Joshua , Hopkins James , Koujah Lulia , Patil Chandrashekhar D. , Hadigal Satvik R. , Kyzar Evan J. , Campeau Anaamika , Wozniak Jacob M. , Gonzalez David J. , Vlodavsky Israel , Li Jin-ping , Perkins David L. , Finn Patricia W. , Shukla Deepak
Published: August 2020

The drive to withstand environmental stresses and defend against invasion is a universal trait extant in all forms of life. While numerous canonical signaling cascades have been characterized in detail, it remains unclear how these pathways interface to generate coordinated responses to diverse stimuli. To dissect these connections, we follow heparanase (HPSE), a protein best known for its endoglycosidic activity at the extracellular matrix but recently recognized to drive various forms of late stage disease through unknown mechanisms. Using herpes simplex virus-1 (HSV-1) infection as a model cellular perturbation, we demonstrate that HPSE acts beyond its established enzymatic role to restrict multiple forms of cell-intrinsic defense and facilitate host cell reprogramming by the invading pathogen. We reveal that cells devoid of HPSE are innately resistant to infection and counteract viral takeover through multiple amplified defense mechanisms. With a unique grasp of the fundamental processes of transcriptional regulation and cell death, HPSE represents a potent cellular intersection with broad therapeutic potential.
3D-printed Planktonic Observational Setup and Analysis Pipeline TrackmateTaxis
Authors: Döring Clemens C. , Hausen Harald
Published: August 2020

Planktonic organisms are a cornerstone of marine ecosystems. They vary significantly in size and have a repertoire of behaviors to aid them to survive and navigate their three-dimensional environment. One of the most important cues is light. A variety of setups were used to study the swimming behavior of specific organisms, but broader and comparative investigations need more versatile solutions. With the help of 3D printing, we designed and constructed a modular and flexible behavioral observation setup that enables recordings of animals down to 50μm or up to a few centimeters. A video analysis pipeline using ImageJ and python allows a quick, automated, and robust tracking solution, capable of processing many videos automatically. A modular light path allows the addition of filters or use of pulse width modulation to equalize photon emission of LEDs or additional LEDs to mix different wavelengths. Optionally, a spectrometer can be installed to enable live monitoring of a stimulus. We tested the setup with two phototactic marine planktonic larvae. First, we investigated the spectral sensitivity of the 7-day old larvae of the polychaeteMalacoceros fuliginosusand second, the behavior of the 200μm spherical bryozoan coronated larvae ofTricellaria inopinatato ultraviolet light coming from the bottom of the vessel. The setup and pipeline were able to record and analyze hundreds of animals simultaneously. We present an inexpensive, modular, and flexible setup to study planktonic behavior of a variety of sizes.
Marcksl1 modulates endothelial cell mechanoresponse to haemodynamic forces to control blood vessel shape and size
Authors: Kondrychyn Igor , Kelly Douglas J. , Carretero Núria Taberner , Nomori Akane , Kato Kagayaki , Chong Jeronica , Nakajima Hiroyuki , Okuda Satoru , Mochizuki Naoki , Phng Li-Kun
Published: August 2020

The formation of vascular tubes is driven by extensive changes in endothelial cell (EC) shape. Here, we have identified a novel role of the actin-binding protein, Marcksl1, in modulating the mechanical properties of EC cortex to regulate cell shape and vessel structure during angiogenesis. Increasing and depleting Marcksl1 expression levelin vivoresulted in an increase and decrease, respectively, in EC size and the diameter of microvessels. Furthermore, endothelial overexpression of Marcksl1 induced ectopic blebbing on both apical and basal membranes, during and after lumen formation, that is suppressed by reduced blood flow. High resolution imaging revealed that Marcksl1 promotes the formation of linear actin bundles and decreases actin density at the EC cortex. Our findings demonstrate that a balanced network of linear and branched actin at the EC cortex is essential in conferring cortical integrity to resist the deforming forces of blood flow to regulate vessel structure.
A versatile X-ray phase retarder for lock-in XMCD measurements
Authors: Poldi Eduardo H. T. , Escanhoela Jr Carlos A. , Fonseca Jr Jairo , Eleotério Marcos A. S. , dos Reis Ricardo D. , Lang Jonathan C. , Haskel Daniel , Souza-Neto Narcizo M.
Published: August 2020

X-ray magnetic circular dichroism (XMCD) is a technique commonly used to probe magnetic properties of materials with element and orbital selectivity, which requires the use of circularly polarized (CP) X-rays. It is possible to accomplish XMCD experiments with fixed CP and alternating the magnetic field orientation, but most reliable data are obtained when alternating the magnetization orientation and the polarization between right and left helicities. A versatile strategy has been developed to perform XMCD experiments using a hard X-ray quarter-wave plate, at both polychromatic dispersive and conventional monochromatic optics, in combination with synchronous data acquisition. The switching frequency waveform is fed into a lock-in amplifier to detect and amplify the XMCD signal. The results on a reference sample demonstrate an improvement in data quality and acquisition time. The instrumentation successfully generated 98% of CP X-rays switching the beam helicity at 13 Hz, with the possibility of faster helicity switching once it is installed at the new Brazilian fourth-generation source, SIRIUS.
Electron-event representation data enable efficient cryoEM file storage with full preservation of spatial and temporal resolution
Authors: Guo Hui , Franken Erik , Deng Yuchen , Benlekbir Samir , Singla Lezcano Garbi , Janssen Bart , Yu Lingbo , Ripstein Zev A. , Tan Yong Zi , Rubinstein John L.
Published: August 2020

Direct detector device (DDD) cameras have revolutionized electron cryomicroscopy (cryoEM) with their high detective quantum efficiency (DQE) and output of movie data. A high ratio of camera frame rate (frames per second) to camera exposure rate (electrons per pixel per second) allows electron counting, which further improves the DQE and enables the recording of super-resolution information. Movie output also allows the correction of specimen movement and compensation for radiation damage. However, these movies come at the cost of producing large volumes of data. It is common practice to sum groups of successive camera frames to reduce the final frame rate, and therefore the file size, to one suitable for storage and image processing. This reduction in the temporal resolution of the camera requires decisions to be made during data acquisition that may result in the loss of information that could have been advantageous during image analysis. Here, experimental analysis of a new electron-event representation (EER) data format for electron-counting DDD movies is presented, which is enabled by new hardware developed by Thermo Fisher Scientific for their Falcon DDD cameras. This format enables the recording of DDD movies at the raw camera frame rate without sacrificing either spatial or temporal resolution. Experimental data demonstrate that the method retains super-resolution information and allows the correction of specimen movement at the physical frame rate of the camera while maintaining manageable file sizes. The EER format will enable the development of new methods that can utilize the full spatial and temporal resolution of DDD cameras.
Risk mitigation in unstabilized approach with fuzzy Bayesian bow-tie analysis
Authors: Acarbay Caner , Kiyak Emre
Published: August 2020

Purpose

Stable approach concept has great importance for the safe operation of an airline during the approach and landing phases. The purpose of this study is to analyse the unstabilized approaches with bow-tie method and determine the threats that may cause risk in an unstable approach.

Design/methodology/approach

In this study, risk assessment of the unstabilized approaches is carried out by using fuzzy bow-tie method and Bayesian networks. Bow-tie method is the combination of event tree analysis and fault tree analysis. Bayesian network is used in the analysis to see interrelationship of basic and intermediate events as well as to update posterior probabilities. Finally, analysis results are verified by the safety performance indicator values.

Findings

In this study, the probabilistic values of the numerical model presented by the risk assessment system for risks were calculated using the fuzzy bow-tie method. Thus, the risk assessment system has been transformed into a structure that can be expressed in a probabilistic manner, and the relationship of the risks within the system has been examined and the effect of a possible change on the risk value has been found to be prevalent.

Originality/value

The bow-tie model is widely applied to assess the risks in aviation. Obtaining prior probabilities is not always possible in the risk assessment process. In this paper, innovative fuzzy bow-tie method is used to assess the risks to overcome the lack of prior probability problem in aviation operations.
Credit booms and financial instability in US agriculture
Authors: Kuethe Todd , Hubbs Todd
Published: August 2020

Purpose

This study examines the relationship between economic fluctuations and financial distress in the US agricultural sector, which is associated with a large degree of financial instability.

Design/methodology/approach

The authors developed a parsimonious model of economic fluctuations in the US agricultural sector. The authors used statistical filter methods to identify the co-movement in cyclical fluctuations in real, cumulative growth rates in farm real estate values, farm sector debt and leverage.

Findings

The proposed model closely approximated the financial evolution of the US agricultural sector between 1960 and 2018. In addition, the authors proved that the proposed model is an early warning indicator of farm loan delinquencies and farm bankruptcies.

Originality/value

This study exploits recent advances in economic theory and empirical macroeconomic modeling to develop a model that is a robust predictor of financial distress in the agricultural sector. Further, the authors demonstrate that the policy interventions following the 1980s farm financial crisis demonstrate the likely long-run economic response to the policies enacted following the 2008 financial crisis.
Developing a new super-efficiency DEA model in the presence of both zero data and stochastic data: a case study in the Iranian airline industry
Authors: Tavassoli Mohammad , Fathi Amirali , Farzipoor Saen Reza
Published: August 2020

Purpose

The purpose of this study is to propose a novel super-efficiency DEA model to appraise the relative efficiency of DMUs with zero data and stochastic data. Our model can work with both variable returns to scale (VRS) and constant returns to scale (CRS).

Design/methodology/approach

This study proposes a new stochastic super-efficiency DEA (SSDEA) model to assess the performance of airlines with stochastic and zero inputs and outputs.

Findings

This paper proposes a new analysis and contribution to the knowledge of efficiency assessment with stochastic super-efficiency DEA model by (1) using input saving and output surplus index for efficient DMUs to get the optimal solution; (2) obtaining efficiency scores from the proposed model that are equivalent to original stochastic super-efficiency model when feasible solutions exist. A case study is given to illustrate the applicability of our proposed model. Also, poor performance reasons are identified to improve the performance of inefficient airlines.

Originality/value

For the first time, a new SSDEA model for ranking DMUs is proposed. The introduced model produces a feasible solution when dealing with zero input or output. This paper applies the input saving and output surplus concept to rectify the infeasibility problem in the stochastic DEA model.
Exploring Deal of the Day: an e-commerce strategy
Authors: Nigam Achint , Dewani Prem Prakash , Behl Abhishek
Published: August 2020

Purpose

This paper examines differences in the discounts offered during Deal of the Day (DOD) promotion schemes by online retailers based on product category, festival season and the economic status of a country.

Design/methodology/approach

In study 1, the authors conducted three focus group studies and 20 in-depth personal interviews (PIs) to explore consumers' perspectives on DOD. To validate the hypotheses based on the findings of study 1 and collected 515 data points from Amazon.com (313 data points from the United States) and Amazon.in (202 data points from India) in study two. The authors used multinomial linear regression to analyze the data.

Findings

A significant difference in savings for buyers on the purchase of electronic product categories as compared to savings made by them on the purchase of non-electronic product categories during DOD promotional schemes. Electronic products get deeper discounts in the US during festival seasons as compared to non-festival seasons during DOD promotional schemes. In emerging economies discounts offered by e-commerce retailers during DOD offers on electronic items are lesser as compared to those offered during DOD offers made in developed economies like United States.

Practical implications

Managers should avoid offering the same products under DOD during the festive season and non-festive season at similar prices in emerging economies as during festivals customers expect more savings over and above the regular savings.

Originality/value

DOD is offered every day irrespective of the other promotions on e-commerce platforms to boost sales. This study analyses any significant difference in saving for DOD offered during special sales days in emerging and developed economies.
Twenty-five years’ contribution of “Benchmarking: an International Journal” to manufacturing strategy: a scientometric review
Authors: Dohale Vishwas , Gunasekaran Angappa , Akarte Milind M. , Verma Priyanka
Published: August 2020

Purpose

This study aims at reviewing the articles on the themes of manufacturing strategy (MS) published in “Benchmarking: An International Journal (BIJ)” and investigating the trends of publication for future research.

Design/methodology/approach

Five-stage methodology to conduct a literature review is adopted comprising: (1) article collection, (2) inclusion/exclusion criteria, (3) reviewing the articles, (4) analyzing the articles and (5) future research directions. A total of 57 articles specific to MS domain published in BIJ are reviewed. Further, a bibliometric analysis comprising keywords co-occurrence, citation and co-citation using a VOSviewer© software followed by content analysis to analyze the type of research, type of industry and type of tool/method used is carried out.

Findings

The study helps to find the scope of the journal and research gaps in the MS domain to provide future research directions. Most of the work found is survey-based or case-based in nature. However, there is a need for empirical research to be done in the field of MS.

Research limitations/implications

The study facilitates researchers willing to publish in BIJ to understand different themes of accepted papers concerning MS domain. The identified research gaps and future research direction can motivate researchers and practitioners to coin new approaches in the MS domain.

Originality/value

A comprehensive review and analysis of the MS literature published in BIJ has been provided. To the best of authors' knowledge, the current study is the only review study in MS domain focusing on one specific journal.
Impact of changing income distribution on fluid milk consumption in urban China
Authors: Zhu Wenbo , Chen Yongfu , Zheng Zhihao , Zhao Jing , Li Guojing , Si Wei
Published: August 2020

Purpose

China has experienced a fast economic growth and shown a significant rise in income inequality in the past decades. During the same period, fluid milk consumption in urban areas has rapidly expanded. The objective of this paper is to analyze and simulate the influence of income distribution changes on fluid milk consumption of households in urban China.

Design/methodology/approach

This study applies an inverse hyperbolic sine (IHS) double-hurdle model to modeling at-home fluid milk consumption of households across different income strata based on a sample of 11,861 urban households in five provinces in China, and simulating the impact of changing income distribution, including five income growth patterns, on fluid milk consumption of total households as well as specific household groups.

Findings

The fluid milk consumption in urban China will continue to increase, with the unconditional income elasticity being 0.334 for the full sample and 0.347, 0.335 and 0.162 for the low-, middle-, and high-income groups, respectively. The simulation results show an evidence that, compared with distribution-neutral and disparity-enlarging income growth patterns, a rising income equality would lead to a more significant increase in fluid milk consumption. And the inequality-reducing income growth pattern has a larger impact on fluid milk consumption of households with seniors and no children, as well as households having no local urban household registration (hukou).

Practical implications

The government should strengthen the supply measures of fluid milk in urban areas, enlarge domestic dairy production, and diversify the sources of milk imports. It is also necessary to subsidize low-income families, especially households with seniors or households migrated from other areas without getting local urbanhukou, which could simultaneously improve nutritional benefits and alleviate financial pressures.

Originality/value

A simulation considering the evolution of income distribution as well as different household groups is conducted. Widely distributed data with a large sample size and detailed demographic information are used. The problems of zero consumption and non-normal distribution are addressed by the IHS double-hurdle model.
Investigating the repurchase intention of Bitcoin: empirical evidence from China
Authors: Nadeem Muhammad Athar , Liu Zhiying , Pitafi Abdul Hameed , Younis Amna , Xu Yi
Published: August 2020

Purpose

Cryptocurrencies, such as Bitcoin, generate innovative and fast exchanges without any physical form and facilitate online payments; thus, they may bring about revolutions of the future economic system. Recent investigations reveal that China, the second largest Bitcoin market, accounts for a huge volume of Bitcoin trading and mining, which can cast distinct influences on future values of Bitcoin. Therefore, it would be of great significance to probe into the repurchase intention of Bitcoin of the Chinese individuals.

Design/methodology/approach

One hundred and forty-three questionnaires were collected from Chinese respondents. SPPS was employed for data analysis of the proposed hypotheses.

Findings

The results show that expectation has a positive impact on perceived enjoyment and perceived ease of use. A positive relationship between perceived ease of use and perceived enjoyment was confirmed. The findings also reveal that expectation, perceived enjoyment and perceived ease of use have significant impact on satisfaction. Moreover, it is found that perceived enjoyment, perceived ease of use and satisfaction significantly influence the repurchase intention of Bitcoin.

Research limitations/implications

This study encourages future comparative studies to be conducted. Besides, it is recommended to find out other possible antecedents of repurchase intention. Moreover, this study suggested negative effects of Bitcoin to be explored.

Practical implications

In a practical standpoint, this study provides valuable suggestions about cryptocurrencies use and regularization. For instance, education and learnability issues of novice users need to be considered. Further, the regularization/implementation of cryptocurrencies/blockchain technologies is also suggested.

Originality/value

This is the pioneer endeavor which investigates the repurchase intention of Bitcoin. The findings explore some of the possible antecedents which influence repurchase intention of Bitcoin. These findings provide valuable insights and enrich the existing body of literature in the domain of Bitcoin.
Integrating hierarchical and network centric management approaches in construction megaprojects using a holonic methodology
Authors: Gorod Alex , Hallo Leonie , Statsenko Larissa , Nguyen Tiep , Chileshe Nicholas
Published: August 2020

Purpose

Traditional “hierarchical” and “network-centric management” approaches often associated with the management of well-defined construction projects lack the adaptability to cope with uncertainty, standardised practices and the required conformance to industry standards. The purpose of this paper is to propose an integrative “holonic” methodology for the management of megaprojects in the construction industry, which incorporates both adaptability and conformance to standards, and to illustrate the associated benefits of such a methodology.

Design/methodology/approach

A multi-case study comprising three cases delivered in the USA and Australia, namely the Adelaide Desalination Plant (ADP), the Seattle–Tacoma International Airport, and the Olmsted Locks and Dam Replacement project were utilized to demonstrate the key features of the hierarchical, network-centric and holonic approaches to managing megaprojects.

Findings

The case studies demonstrate incorporating the holonic approach into the management of complex construction projects results in increased management effectiveness and project success. The proposed “holonic” methodology provides the potential to efficiently manage megaprojects navigating through high degrees of uncertainty.

Practical implications

The adoption of the holonic view by project management (PM) practitioners will help them manage megaprojects that are characterised by greater complexity. Second, the proposed methodology enables the discipline of PM to evolve in alignment with rapidly unfolding global transformation trends.

Originality/value

This paper demonstrates the application of the “holonic” methodology to the domain of the management of construction megaprojects. Such an approach is needed as construction projects become increasingly more complex across the world due to technological, political and social uncertainties, larger scale, changing environmental and safety regulations, and the growing involvement of human factors germane to this research.
Understanding the role of technological factors and external pressures in smart classroom adoption
Authors: Selim Hassan M. , Eid Riyad , Agag Gomaa
Published: August 2020

Purpose

The adoption of smart classroom is increasing in higher education around the world. Yet, factors affecting smart classroom adoption have not been sufficiently explored. Based on the innovation diffusion theory and external pressures, the present study developed a model to investigate the main drivers of smart classroom adoption.

Design/methodology/approach

SEM-AMOS was used to analyse the data collected from a sample of 1,208 educators.

Findings

The findings revealed that innovation diffusion theory and external pressures provide an appropriate model for understanding smart classroom adoption.

Practical implications

The findings offer important implications for higher education institutions, IT managers, and are likely to stimulate further research in the area of smart classrooms.

Originality/value

To the best of the authors' knowledge, this is the first study that used innovation diffusion theory external pressures to understanding smart classroom adoption.
Customers’ intention to use robot-serviced restaurants in Korea: relationship of coolness and MCI factors
Authors: Cha Seong Soo
Published: August 2020

Purpose

This study aims to empirically test a theoretical model by defining customers’ intention to use services of restaurant robots, which are rapidly developing in Korea. The proposed model incorporates three stages: coolness, motivated consumer innovativeness (MCI) and the theory of planned behaviour.

Design/methodology/approach

A total of 420 questionnaires were issued. The results were analysed to verify the reliability and validity of the measured variables. Structural equation modelling was used to test the research hypotheses.

Findings

The results showed that hedonically motivated consumer innovativeness (hMCI) and socially motivated consumer innovativeness (sMCI) have positive effects on attitude and are enhanced by attractiveness, utility, subcultural appeal and originality. However, the relationship between MCI and attitude differed among age groups.

Practical implications

The results revealed that sensory elements of robot services improve customer attitudes towards the use of robots in restaurants. This is a key finding that restaurant marketers should consider, because non-face-to-face services are becoming increasingly important in the current COVID-19 context.

Originality/value

This study analysed the relationship between coolness, MCI and the theory of planned behaviour in the context of robot-serviced restaurants and how the relationship between MCIs and attitude differed among the young and older customers. Practical implications are suggested.
Barriers to multi-tier supply chain risk management
Authors: Wang-Mlynek Liyuan , Foerstl Kai
Published: August 2020

Purpose

Multi-tier supply chain risk management (MSCRM) is an evolving and dynamic field, as any defaults or glitches in supply chains can potentially harm the efficiency and competitiveness of the entire supply chain. This study aims to investigate barriers to MSCRM in the automotive and civil aircraft industries.

Design/methodology/approach

This study adopts an inductive case study research design. The case analysis includes two parts. First, the within-case analysis develops case profiles and identifies critical categories. Second, the cross-case analysis compares MSCRM patterns across the cases.

Findings

This study argues that narrow information sharing and communication covering only the immediate supply chain partners obstruct the efficiency of MSCRM. Similarly, high dependency on strategic alliances with suppliers hinders efficient MSCRM. Additionally, relying on information and communication technologies (ICT) increases companies' exposure to risks and poses another barrier to efficient MSCRM.

Research limitations/implications

Further research should be pursued to expand generalizability and test the validity of the findings using other forms of data collection and methodologies, such as large-scale surveys, experiments or secondary data across different sectors and typical supply networks.

Practical implications

This study provides empirical evidence on the obstacles faced by companies during the process of MSCRM. These findings can guide practitioners in developing initiatives to overcome these challenges.

Originality/value

This study is among the first to investigate the barriers to MSCRM in the automotive and civil aircraft industries using in-depth case studies across three tiers of the supply chain.
SARS n-CoV2-19 detection from chest x-ray images using deep neural networks
Authors: Pandit Mohammad Khalid , Banday Shoaib Amin
Published: August 2020

Purpose

Novel coronavirus is fast spreading pathogen worldwide and is threatening billions of lives. SARS n-CoV2 is known to affect the lungs of the COVID-19 positive patients. Chest x-rays are the most widely used imaging technique for clinical diagnosis due to fast imaging time and low cost. The purpose of this study is to use deep learning technique for automatic detection of COVID-19 using chest x-rays.

Design/methodology/approach

The authors used a data set containing confirmed COVID-19 positive, common bacterial pneumonia and healthy cases (no infection). A collection of 1,428 x-ray images is used in this study. The authors used a pre-trained VGG-16 model for the classification task. Transfer learning with fine-tuning was used in this study to effectively train the network on a relatively small chest x-ray data set. Initial experiments show that the model achieves promising results and can be greatly used to expedite COVID-19 detection.

Findings

The authors achieved an accuracy of 96% and 92.5% in two and three output class cases, respectively. Based on these findings, the medical community can access using x-ray images as possible diagnostic tool for faster COVID-19 detection to complement the already testing and diagnosis methods.

Originality/value

The proposed method can be used as initial screening which can help health-care professionals to better treat the COVID patients by timely detecting and screening the presence of disease.