bluuebunny/crossref_metadata_2025 huggingface dataset:
SARS-CoV-2 antibody prevalence in Sierra Leone, March 2021: a cross-sectional, nationally representative, age-stratified serosurvey
Authors: Barrie Mohamed Bailor , Lakoh Sulaiman , Kelly J. Daniel , Kanu Joseph Sam , Squire James , Koroma Zikan , Bah Silleh , Sankoh Osman , Brima Abdulai , Ansumana Rashid , Goldberg Sarah A. , Chitre Smit , Osuagwu Chidinma , Maeda Justin , Barekye Bernard , Numbere Tamuno-Wari , Abdulaziz Mohammed , Mounts Anthony , Blanton Curtis , Singh Tushar , Samai Mohamed , Vandi Mohamed A. , Richardson Eugene T.
Published: July 2021

Background

As of 26 March 2021, the Africa CDC had reported 4,159,055 cases of COVID-19 and 111,357 deaths among the 55 African Union Member States; however, no country has published a nationally representative serosurvey as of May 2021. Such data are vital for understanding the pandemic’s progression on the continent, evaluating containment measures, and policy planning.

Methods

We conducted a cross-sectional, nationally representative, age-stratified serosurvey in Sierra Leone in March 2021 by randomly selecting 120 Enumeration Areas throughout the country and 10 randomly selected households in each of these. One to two persons per selected household were interviewed to collect information on socio-demographics, symptoms suggestive of COVID-19, exposure history to laboratory-confirmed COVID-19 cases, and history of COVID-19 illness. Capillary blood was collected by fingerstick, and blood samples were tested using the Hangzhou Biotest Biotech RightSign COVID-19 IgG/IgM Rapid Test Cassette. Total seroprevalence was was estimated after applying sampling weights.

Findings

The overall weighted seroprevalence was 2.6% (95% CI 1.9-3.4). This is 43 times higher than the reported number of cases. Rural seropositivity was 1.8% (95% CI 1.0-2.5), and urban seropositivity was 4.2% (95% CI 2.6-5.7).

Interpretation

Although overall seroprevalence was low compared to countries in Europe and the Americas (suggesting relatively successful containment in Sierra Leone), our findings indicate enormous underreporting of active cases. This has ramifications for the country’s third wave (which started in June 2021), where the average number of daily reported cases was 87 by the end of the month—this could potentially be on the order of 3,700 actual infections, calling for stronger containment measures in a country with only 0.2% of people fully vaccinated. It may also reflect significant underreporting of incidence and mortality across the continent.

Funding

This study was supported by NIAID K08 AI139361, the Sierra Leone Ministry of Health and Sanitation, and the Africa CDC.
The health impacts of a 4-month long community-wide COVID-19 lockdown: Findings from a prospective longitudinal study in the state of Victoria, Australia
Authors: Griffiths Daniel , Sheehan Luke , Petrie Dennis , van Vreden Caryn , Whiteford Peter , Collie Alex
Published: July 2021

Objectives

To determine health impacts during, and following, an extended community lockdown and COVID-19 outbreak in the Australian state of Victoria, compared with the rest of Australia.

Methods

A national cohort of 898 working-age Australians enrolled in a longitudinal cohort study, completing surveys before, during, and after a 112-day community lockdown in Victoria (8 July – 27 October 2020). Outcomes included psychological distress, mental and physical health, work, social interactions and finances. Regression models examined health changes during and following lockdown.

Results

The Victorian lockdown led to increased psychological distress. Health impacts coincided with greater social isolation and work loss. Following the extended lockdown, mental health, work and social interactions recovered to an extent whereby no significant long-lasting effects were identified in Victoria compared to the rest of Australia.

Conclusion

The Victorian community lockdown had adverse health consequences, which reversed upon release from lockdown. Governments should weigh all potential health impacts of lockdown. Services and programs to reduce the negative impacts of lockdown may include increases in mental health care, encouraging safe social interactions and supports to maintain employment relationships.
Sigma70Pred: A highly accurate method for predicting sigma70 promoter in prokaryotic genome
Authors: Patiyal Sumeet , Singh Nitindeep , Ali Mohd. Zartab , Pundir Dhawal Singh , Raghava Gajendra P.S.
Published: July 2021

Sigma70 factor plays a crucial role in prokaryotes and regulates the transcription of most of the housekeeping genes. One of the major challenges is to predict the sigma70 promoter or sigma70 factor binding site with high precision. In this study, we trained and evaluate our models on a dataset consists of 741 sigma70 promoters and 1400 non-promoters. We have generated a wide range of features around 8000 which includes Dinucleotide Auto-Correlation, Dinucleotide Cross-Correlation, Dinucleotide Auto Cross-Correlation, Moran Auto-Correlation, Normalized Moreau-Broto Auto-Correlation, Parallel Correlation Pseudo Tri-Nucleotide Composition, etc. Our SVM based model achieved maximum accuracy 97.38% with AUROC 0.99 on training dataset, using 200 selected features. In order to check the robustness of our model we have tested our model on the independent dataset made by using latest version of RegulonDB10.8, which included 1134 sigma70 and 638 non-sigma70 promoters, and able to achieve accuracy of 90.41% with AUROC of 0.95. We have developed a method, Sigma70Pred, which is available as webserver and standalone packages at https://webs.iiitd.edu.in/raghava/sigma70pred/. The services are freely accessible.
Clonal hematopoiesis of indeterminate potential is associated with worse kidney function and anemia in a cohort of patients with advanced chronic kidney disease
Authors: Vlasschaert Caitlyn , McNaughton Amy J. M. , Hopman Wilma , Kestenbaum Bryan , Robinson-Cohen Cassianne , Garland Jocelyn , Moran Sarah M. , Holden Rachel , Lanktree Matthew B. , Rauh Michael J.
Published: July 2021

Background

Clonal hematopoiesis of indeterminate potential (CHIP) is an inflammatory premalignant disorder resulting from acquired genetic mutations in hematopoietic stem cells. CHIP is common in aging populations and associated with cardiovascular morbidity and overall mortality, but its role in chronic kidney disease (CKD) has not been investigated.

Methods

We performed targeted sequencing to detect CHIP mutations in a cohort of 87 adults with eGFR < 60 ml/min/1.73m2. Kidney function, hematologic, and mineral bone disease parameters were assessed cross-sectionally at baseline, and a total of 2,091 creatinine measurements and 3,382 hemoglobin measurements were retrospectively collected over the following 12-year period.

Results

At baseline, 20 of 87 (23%) cohort participants had CHIP detected. Those with CHIP had lower baseline eGFR (22.3 ± 11.2 vs. 28.2 ± 11.5 ml/min/1.73 m2, P = 0.04) in age- and sex-adjusted regression models. Individuals with CHIP had a 2.5–fold increased risk of incident 50% decline in eGFR or ESKD in a Cox proportional hazard model adjusted for age and sex (95% confidence interval, 1.3–4.7). The annualized rate of eGFR decline adjusted for age and sex was -2.3 ±1.1 ml/min/1.73m2 per year in those with CHIP versus -1.6 ±0.5 ml/min/1.73m2 per year in those without CHIP. Further, those with CHIP had lower hemoglobin at baseline (11.6 ± 0.3 vs. 12.8 ± 0.2 g/dL, P = 0.0003) and throughout the follow-up period despite a greater use of erythropoiesis-stimulating agents.

Conclusion

In those with pre-existing CKD, CHIP was associated with lower eGFR at baseline, faster progression of CKD, and anemia.
Intrinsic Network Connectivity Reflects the Cyclic Trajectory of Migraine Attacks
Authors: Stankewitz Anne , Schulz Enrico
Published: July 2021

Background

Episodic migraine is considered to be cyclic in nature, triggered by the hypothalamus. To assess the natural trajectory of intrinsic networks over an entire migraine cycle, we designed a longitudinal intra-individual study using functional magnetic resonance imaging (fMRI).

Methods

Intrinsic network connectivity was assessed for 12 migraineurs in 82 sessions including spontaneous, untriggered headache attacks and follow-up recordings towards the next attack.

Results

We found cyclic changes in the visual, auditory, and somatosensory networks, in limbic networks (e.g. thalamo-insular, parahippocampal), and in the salience network (anterior insula and dorsal anterior cingulate cortex). Connectivity changes also extended to further cortical networks, such as the central executive network, the default mode network, as well as subcortical networks.

Almost all of these network connectivity changes followed the trajectory of a linear increase over the pain-free interval that peaked immediately prior to the headache, and “dropped” to the baseline level during the headache. These network alterations are associated with a number of cortical functions that may explain the variety of ictal and pre-ictal physiological and psychological migraine symptoms.

Conclusion

Our results suggest that migraine disease is associated with widespread cyclic alterations of intrinsic networks that develop before the headache is initiated, i.e. during the interictal and premonitory phase. The increasing magnitude of connectivity within these networks towards the next attack may reflect an increasing effort to maintain network integrity.
Oculomotor plant and neural dynamics suggest gaze control requires integration on distributed timescales
Authors: Miri Andrew , Bhasin Brandon J. , Aksay Emre R. F. , Tank David W. , Goldman Mark S.
Published: July 2021

A fundamental principle of biological motor control is that the neural commands driving movement must conform to the response properties of the motor plants they control. In the oculomotor system, characterizations of oculomotor plant dynamics traditionally supported models in which the plant responds to neural drive to extraocular muscles on exclusively short, subsecond timescales. These models predict that the stabilization of gaze during fixations between saccades requires neural drive that approximates eye position on longer timescales and is generated through the temporal integration of brief eye velocity-encoding signals that cause saccades. However, recent measurements of oculomotor plant behaviour have revealed responses on longer timescales. Furthermore, measurements of firing patterns in the oculomotor integrator have revealed a more complex encoding of eye movement dynamics. Yet, the link between these observations has remained unclear. Here we use measurements from the larval zebrafish to link dynamics in the oculomotor plant to dynamics in the neural integrator. The oculomotor plant in both anaesthetized and awake larval zebrafish was characterized by a broad distribution of response timescales, including those much longer than one second. Analysis of the firing patterns of oculomotor integrator neurons, which exhibited a broadly distributed range of decay time constants, demonstrates the sufficiency of this activity for stabilizing gaze given an oculomotor plant with distributed response timescales. This work suggests that leaky integration on multiple, distributed timescales by the oculomotor integrator reflects an inverse model for generating oculomotor commands, and that multi-timescale dynamics may be a general feature of motor circuitry.

KEY POINTS

Recent observations of oculomotor plant response properties and neural activity across the oculomotor system have called into question classical formulations of both the oculomotor plant and the oculomotor integrator.

Here we use measurements from new and published experiments in the larval zebrafish together with modelling to reconcile recent oculomotor plant observations with oculomotor integrator function.

We developed computational techniques to characterize oculomotor plant responses over several seconds in awake animals, demonstrating that long timescale responses seen in anesthetized animals extend to the awake state.

Analysis of firing patterns of oculomotor integrator neurons demonstrates the sufficiency of this activity for stabilizing gaze given an oculomotor plant with multiple, distributed response timescales.

Our results support a formulation of gaze stabilization by the oculomotor system in which commands for stabilizing gaze are generated through integration on multiple, distributed timescales.
On the topochronic map of the human brain dynamics
Authors: Sorrentino P. , Petkoski S. , Sparaco M. , Troisi Lopez E. , Signoriello E. , Baselice F. , Bonavita S. , Pirozzi M.A. , Quarantelli M. , Sorrentino G. , Jirsa V.
Published: July 2021

Two structurally connected brain regions are more likely to interact, with the lengths of the structural bundles, their widths, myelination, and the topology of the structural connectome influencing the timing of the interactions. We introduce an in vivo approach for measuring functional delays across the whole brain using magneto/electroencephalography and integrating them with the structural bundles. The resulting topochronic map of the functional delays/velocities shows that larger bundles have faster velocities. We estimated the topochronic map in multiple sclerosis patients, who have damaged myelin sheaths, and controls, demonstrating greater delays in patients across the network and that structurally lesioned tracks were slowed down more than unaffected ones. We provide a novel framework for estimating functional transmission delays in vivo at the single-subject and single-fiber level.

One-Sentence Summary

A non-invasive estimation of the individual deterministic spatio-temporal scaffold underlying the evolution of brain dynamics.
CRISPRa screening with real world evidence identifies potassium channels as neuronal entry factors and druggable targets for SARS-CoV-2
Authors: Wang Chengkun , Dinesh Ravi K. , Qu Yuanhao , Rustagi Arjun , Cousins Henry , Zengel James , Zhang Tianyi , Magazine Nicholas , Guo Yinglong , Hall Taryn , Beck Aimee , Heilbroner Lucas Miecho , Peters-Schulze Grace , Wilk Aaron , Tso Luke , Erdemic Elif Tokar , Tanudtanud Kae , Ren Sheng , Tzeng Kathy Tzy-Hwa , Wang Mengdi , Howitt Brooke , Huang Weishan , Carette Jan , Altman Russ , Blish Catherine A. , Cong Le
Published: July 2021

Although vaccines for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have been successful, there are no good treatments for those who are actively infected. While SARS-CoV-2 primarily infects the respiratory tract, clinical evidence indicates that cells from sensory organs and the brain are also susceptible to infection. While many patients suffer from diverse neurological symptoms, the virus’s neuronal entry remains mysterious. To discover host factors involved in SARS-CoV-2 viral entry, we performed CRISPR activation (CRISPRa) screens targeting all 6000+ human membrane proteins in cells with and without overexpression of ACE2 using Spike-pseudotyped lentiviruses. This unbiased gain-of-function screening identified both novel and previously validated host factors. Notably, newly found host factors have high expression in neuronal and immune cells, including potassium channel KCNA6, protease LGMN, and MHC-II component HLA-DPB1. We validated these factors using replication-competent SARS-CoV-2 infection assays. Notably, the overexpression of KCNA6 led to a marked increase in infection even in cells with undetectable levels of ACE2 expression. Analysis of human olfactory epithelium scRNA-seq data revealed that OLIG2+/TUJ1+ cells--previously identified as sites of infection in COVID-19 autopsy studies-- have high KCNA6 expression and minimal levels of ACE2. The presence of KCNA6 may thus explain sensory/neuronal aspects of COVID-19 symptoms. Further, we demonstrate that FDA-approved compound dalfampridine, an inhibitor of KCNA-family potassium channels, suppresses viral entry in a dosage-dependent manner. Finally, we identified common prescription drugs likely to modulate the top identified host factors, and performed a retrospective analysis of insurance claims of ~8 million patients. This large cohort study revealed a statistically significant association between top drug classes, particularly those targeting potassium channels, and COVID-19 severity. Taken together, the potassium channel KCNA6 facilitates neuronal entry of SARS-CoV-2 and is a promising target for drug repurposing and development.
Single-cell anatomical analysis of human hippocampus and entorhinal cortex uncovers early-stage molecular pathology in Alzheimer’s disease
Authors: Davila-Velderrain Jose , Mathys Hansruedi , Mohammadi Shahin , Ruzicka Brad , Jiang Xueqiao , Ng Ayesha , Bennett David A. , Tsai Li-Huei , Kellis Manolis
Published: July 2021

The human hippocampal formation plays a central role in Alzheimer’s disease (AD) progression, cognitive traits, and the onset of dementia; yet its molecular states in AD remain uncharacterized. Here, we report a comprehensive single-cell transcriptomic dissection of the human hippocampus and entorhinal cortex across 489,558 cells from 65 individuals with varying stages of AD pathology. We transcriptionally characterize major brain cell types and neuronal classes, including 17 glutamatergic and 8 GABAergic neuron subpopulations. Combining evidence from human and mouse tissue-microdissection, neuronal cell isolation and spatial transcriptomics, we show that single-cell expression patterns capture fine-resolution neuronal anatomical topography. By stratifying subjects into early and late pathology groups, we uncover stage-dependent and cell-type specific transcriptional modules altered during AD progression. These include early-stage cell-type specific dysregulation of cellular and cholesterol metabolism, late-stage neuron-glia alterations in neurotransmission, and late-stage signatures of cellular stress, apoptosis, and DNA damage broadly shared across cell types. Late-stage signatures show signs of convergence in hippocampal and cortical cells, while early changes diverge; highlighting the relevance of characterizing molecular pathology across brain regions and AD progression. Finally, we characterize neuron subregion-specific responses to AD pathology and show that CA1 pyramidal neurons are the most transcriptionally altered while CA3 and dentate gyrus granule neurons the least. Our study provides a valuable resource to extend cell type-specific studies of AD to clinically relevant brain regions affected early by pathology in disease progression.
High-density transposon mutagenesis in Mycobacterium abscessus identifies an essential penicillin-binding lipo-protein (PBP-lipo) involved in septal peptidoglycan synthesis and antibiotic sensitivity
Authors: Akusobi Chidiebere , Benghomari Bouchra S. , Zhu Junhao , Wolf Ian D. , Singhvi Shreya , Dulberger Charles L. , Ioerger Thomas R. , Rubin Eric J.
Published: July 2021

Mycobacterium abscessus (Mab) is a rapidly growing non-tuberculous mycobacterium (NTM) that causes a wide range of infections. Treatment of Mab infections is difficult because the bacterium is intrinsically resistant to many classes of antibiotics. Developing new and effective treatments against Mab requires a better understanding of the unique vulnerabilities that can be targeted for future drug development. To achieve this, we identified essential genes in Mab by conducting transposon-sequencing (TnSeq) on the reference Mab strain ATCC 19977. We generated ∼51,000 unique transposon mutants and used this high-density library to identify 362 essential genes for in vitro growth. To investigate species-specific vulnerabilities in Mab, we further characterized MAB_3167c, a predicted penicillin-binding-lipoprotein (PBP-lipo) that is essential in Mab and non-essential in Mycobacterium tuberculosis (Mtb). We found that PBP-lipo primarily localizes to the subpolar region and later to the septum as cells prepare to divide. Depletion of Mab PBP-lipo causes cells to elongate, develop ectopic branches, and form multiple septa. Knockdown of PBP-lipo along with PbpB, DacB1, and a carboxypeptidase, MAB_0519 lead to synergistic growth arrest. In contrast, these genetic interactions were absent in the Mtb model organism, Mycobacterium smegmatis, indicating that the PBP-lipo homologs in the two species exist in distinct genetic networks. Finally, repressing PBP-lipo sensitized the reference strain and 11 Mab clinical isolates to several classes of antibiotics, including the β-lactams, ampicillin and amoxicillin by greater than 128-fold. Altogether, this study presents PBP-lipo as a key enzyme to study Mab specific processes in cell wall synthesis and importantly positions PBP-lipo as an attractive drug target to treat Mab infections.
Crystal structure and Hirshfeld surface analysis of a pyrrolo-thiazine complex
Authors: Sribala R. , Srinivasan N. , Rajalaksmi P. , Indumathi S. , Krishnakumar R.V.
Published: July 2021

In the title compound, diethyl 2,2-dioxo-4-(thiophen-2-yl)-1-[(thiophen-2-yl)methyl]-3,4,6,7,8,8a-hexahydro-1H-pyrrolo[2,1-c][1,4]thiazine-1,3-dicarboxylate, C22H28NO6S3, the pyrrolo ring is in an envelope conformation while the thiazine ring adopts a near chair conformation. The dihedral angles between the thiazine ring and the methylthienyl, thienyl and pyrrolo rings are 64.0 (2), 87.92 (7) and 5.6 (2)°, respectively. In the crystal, the molecules are linked by weak C—H...O hydrogen bonds. A Hirshfeld surface analysis was performed to investigate the intermolecular interactions. Disorder of the methylthienyl group with site occupancies of 0. 792 (3) and 0.208 (3) is observed
Institutional pressures, environmental management practices, firm characteristics and environmental performance
Authors: Bananuka Juma , Bakalikwira Lasuli , Nuwagaba Patience , Tumwebaze Zainabu
Published: July 2021

Purpose

The purpose of this paper is twofold: to establish the contribution of institutional pressures, environmental management practices and firm characteristics to environmental performance; and to establish whether environmental management practices mediate the relationship between institutional pressures and environmental performance.

Design/methodology/approach

Using a cross-sectional design, data were collected through a questionnaire survey of 303 manufacturing firms in Uganda. Data were analyzed using Statistical Package for Social Sciences and MedGraph program (Excel version).

Findings

Both environmental management practices and institutional pressures are significant predictors of environmental performance. Results further suggest that environmental management practices partially mediate the relationship between institutional pressures and environmental performance. Variables that represent firm characteristics are not significantly associated with environmental performance.

Originality/value

This study provides an initial empirical evidence on the mediating role of environmental management practices in the relationship between institutional pressures and environmental performance. It also enhances our understanding of the contribution of individual dimensions of environmental management practices and institutional pressures to environmental performance using evidence from an emerging economy setting.
Commitment in an organizational context: a SET-theoretic approach that provides management tools
Authors: Curado Carla , Jerónimo Helena Mateus , Henriques Paulo Lopes , Tavares Marta
Published: July 2021

Purpose

Grounded on the social exchange theory (SET), this paper aims to analyze the different networks of conditions that lead to the presence and absence of total commitment, in its affective, continuance and normative dimensions. Six conditions – competencies development, empowerment, work-family conflict, trust, transformational leadership and seniority – are studied to explore and explain the exchanges and reciprocity relationships between organizations and employees.

Design/methodology/approach

Using a sample of 546 employees from Portuguese large companies, the study uses the fuzzy-set qualitative comparative analysis (fsQCA) to explore how causal conditions jointly link to the outcome of organizational commitment.

Findings

The results show more causal configurations leading to the most favorable dimensions of commitment (affective, normative and the absence of continuance commitment), which is a positive sign for organizations. Employees' seniority stands out in all types of commitment, reflecting the affective and emotional themes in Portuguese culture.

Originality/value

This study makes an original contribution to the literature on organizational commitment by showing the alternative complementarity of the conditions in the context of the SET, only possible through fsQCA. It also provides inputs for practitioners who can adopt strategies and measures to develop the paths that lead to successful outcomes (presence of commitment) and avoid those that lead to undesired ones (absence of commitment).
Stagnation point flow toward an exponentially shrinking sheet in a hybrid nanofluid
Authors: Waini Iskandar , Pop Ioan , Abu Bakar Sakhinah , Ishak Anuar
Published: July 2021

Purpose

This paper aims to investigate the radiation and magnetohydrodynamic effect on the flow toward a stagnation point of an exponentially shrinking sheet in a hybrid nanofluid.

Design/methodology/approach

The governing partial differential equations are transformed into a set of similarity equations and are then solved numerically using the boundary value problem solver, bvp4c, available in MATLAB software. The effects of several physical parameters on the flow and the thermal characteristics of the hybrid nanofluid are analyzed and discussed.

Findings

Numerical results clarify that the dual solutions arise for the shrinking case (λ < 0). The critical values expand for the stronger magnetic field. Besides, the skin friction and the heat transfer coefficients enhance with the rise of the magnetic field and the hybrid nanoparticles. The heat transfer rate increases by 10.11% for the nanofluid and 28.69% for the hybrid nanofluid compared to the regular fluid. In addition, the presence of radiation gives a higher heat transfer rate. Using the stability analysis, it is found that the first solution is stable, and the second solution is unstable, over time.

Originality/value

The stagnation point flow problem has been widely studied for the flow over a stretching sheet, but only limited findings can be found for the flow over a shrinking sheet. Therefore, the present study considers the problem of the stagnation point flow over a shrinking sheet in a Cu-Al2O3/water hybrid nanofluid with the effects of magnetic field and thermal radiation. The dual solutions of the hybrid nanofluid flow over a shrinking sheet are obtained. Further analysis shows that only one of the solutions is stable and thus physically reliable as time evolves.
Improving student satisfaction and learning outcomes with service quality of online courses: evidence from Thai and Indonesian higher education institutions
Authors: Darawong Chonlatis , Widayati Ani
Published: July 2021

Purpose

The purpose of this article is to compare Thai students with Indonesian students in regard to the impact of four service quality dimensions on student satisfaction and the learning outcomes of online courses.

Design/methodology/approach

Samples were 352 Indonesian and 380 Thai students who were in bachelor's degree programmes and experienced online course services.

Findings

For Thai samples, however, the strongest dimension of service quality affecting student satisfaction is reliability, followed by responsiveness and competence, accordingly. For Indonesian samples, the strongest effect service quality dimension affecting student satisfaction is empathy, followed by responsiveness, competence and reliability.

Research limitations/implications

First, the sample consisted of online course students from two countries, Thailand and Indonesia. The findings may not be generalized to other countries where teaching and learning cultures are largely different. Second, four service quality dimensions were examined for their influence on student satisfaction, which consequently affects learning outcomes.

Practical implications

Firstly, instructors should strictly follow what they promise to their students. Secondly, a communication network should be developed to minimize possible misunderstandings. Thirdly, faculty administrations should provide training programmes for online instructors to enhance their competence. Lastly, online instructors need appropriate support mechanisms for technical issues and mishaps that students may face in technology-enhanced learning environments.

Originality/value

This study performs an original survey conducted in Thailand and Indonesia and reports the results based on the data analysis and the interpretation of research findings.
COVID-19 complications and economic recovery of China: guidelines for other economies
Authors: Soomro Bahadur Ali , Mangi Shah Nawaz , Shah Naimatullah
Published: July 2021

Purpose

Coronavirus (COVID-19) brought massive economic damage throughout the globe. Economic as well as social set-ups have enormously collapsed. The present paper underlines some economic complications of China during COVID-19. The study also sheds light on initiatives taken by the government of China to fight against such a damaging pandemic.

Design/methodology/approach

The study employed secondary research or desk research that involves existing data. The data were collected from reliable sources, described below. The data were summarized and organized to increase the overall efficacy and reliability of the research.

Findings

The study finds that China has confronted many downturns in export and import, GDP decline, blockage of markets and production evaluation. To recover from these unfavorable and adverse circumstances, China has recovered its economy by introducing digital transformation, effective legislations, A V-shaped recovery and A U-shaped recovery in manufacturing and services.

Practical implications

China's steps and initiatives to invigorate economic developments during a pandemic would be beneficial for other economies facing the severe challenges of economic development, especially after COVID-19.

Originality/value

The present study is one of the rare studies of the domain that offers the guidelines to the policymakers and economists of developing countries to develop their policies regarding the digital economy to face the traditional market's challenges.
The relationship between management entrenchment and financial statement fraud
Authors: Seifzadeh Maryam , Rajaeei Raha , Allahbakhsh Arezao
Published: July 2021

Purpose

This study aims to assess the relationship between managerial entrenchment and the chance of fraud in financial statements, which are the only available source for shareholders’ decisions, so their accuracy and reliability are of great importance. Hence, the realization of contributing factors to preventing financial information distortion is vital. Moreover, managerial entrenchment on the chance of fraud in the company’s upcoming years has also been analyzed.

Design/methodology/approach

The factor analysis of five variables [chief executive officer (CEO) duality, managerial ownership, board independence, board compensation and CEO tenure] is used for management entrenchment. To examine the hypothesis testing, multivariate regressions, feasible general least squares regression and Logit model regression are used. The statistical sample under study in this paper includes 1,122 year-company observations during 2013–2018 and Beneish’s (1999) model is used for evaluating fraud.

Findings

The study results show a negative and significant relationship between management entrenchment and the chance of fraud in financial statements. That means managers with a higher degree of managerial entrenchment are more likely to create value and acquire wealth for the firm, and that causes them not to waste and waste the firm resources through enhancing the supervisory mechanisms. Moreover, the study results also show that improving and strengthening management entrenchment will lower the upcoming years’ fraud condition.

Originality/value

The current paper is the first time that the relationship between managerial entrenchment and financial statement fraud is assessed within a study. The results of the paper help the beneficiaries and shareholders realize different aspects of management entrenchment. That means managers’ power and authority can be used to make shareholders’ interests, but they can hinder misuse and fraud.
Does cluttered social media environment hurt advertising effectiveness? The moderation of ad types and personalization
Authors: Jung A-Reum , Heo Jun
Published: July 2021

Purpose

The purpose of this study is to figure out the factors (i.e. ad type and ad personalization) that diminish the detrimental advertising clutter effects in terms of ad attention and ad clicks.

Design/methodology/approach

To fulfill the purpose, an eye-tracking study using real-time Facebook accounts of the participants was conducted.

Findings

The findings suggest that not all types of ad format face attentional competition. Consumers have a tendency to selectively care of native advertising area, where clutter becomes a significant issue. Additionally, personalized advertising is beneficial for attracting consumer attention regardless of the clutter level.

Originality/value

This less-artificial study setting with an eye-tracker makes up for the findings from previous ad clutter studies based on self-reported data; this study was able to observe real-life interaction between consumers and social media. The personalized native format may benefit advertisers in grabbing more attention. However, the careful use of native ads is recommended, because excessive ads could increase the attentional competition among native ads.
Understanding innovativeness and commitment to sustainable service practices
Authors: Marín-García Antonio , Gil-Saura Irene , Ruiz-Molina Maria-Eugenia
Published: July 2021

Purpose

The purpose of this study is two-fold. First, to examine the relationship between the retailer’s innovativeness and sustainability from the customer standpoint. Second, to assess the impact of the retailer’s innovativeness and commitment toward sustainability as perceived by the consumer on store image and store equity.

Design/methodology/approach

To achieve this objective, a theoretical model is proposed based on the literature that is tested through an empirical study conducted on a sample of 510 customers of three grocery retail formats – i.e. hypermarkets, supermarkets and discount stores.

Findings

The results obtained confirm the hypotheses proposed and, consequently, both innovation and sustainability emerge as key elements in the development of store equity through store image.

Originality/value

This study allows to draw a set of managerial recommendations for food retailers based on the benefits of investing in innovative processes, that boosted by the implementation of innovative solutions, assist in the development of sustainable practices, thus allowing improvements in store image and store brand equity.
Interval type-2 fuzzy inference-based failure mode and effect analysis model in a group decision-making setting
Authors: Gölcük İlker
Published: July 2021

Purpose

This paper proposes an integrated IT2F-FMEA model under a group decision-making setting. In risk assessment models, experts' evaluations are often aggregated beforehand, and necessary computations are performed, which in turn, may cause a loss of information and valuable individual opinions. The proposed integrated IT2F-FMEA model aims to calculate risk priority numbers from the experts' evaluations and then fuse experts' judgments using a novel integrated model.

Design/methodology/approach

This paper presents a novel failure mode and effect analysis (FMEA) model by integrating the fuzzy inference system, best-worst method (BWM) and weighted aggregated sum-product assessment (WASPAS) methods under interval type-2 fuzzy (IT2F) environment. The proposed FMEA approach utilizes the Mamdani-type IT2F inference system to calculate risk priority numbers. The individual FMEA results are combined by using integrated IT2F-BWM and IT2F-WASPAS methods.

Findings

The proposed model is implemented in a real-life case study in the furniture industry. According to the case study, fifteen failure modes are considered, and the proposed integrated method is used to prioritize the failure modes.

Originality/value

Mamdani-type singleton IT2F inference model is employed in the FMEA. Additionally, the proposed model allows experts to construct their membership functions and fuzzy rules to capitalize on the experience and knowledge of the experts. The proposed group FMEA model aggregates experts' judgments by using IT2F-BWM and IT2F-WASPAS methods. The proposed model is implemented in a real-life case study in the furniture company.
Mixed frequency domain spillover effect of international economic policy uncertainty on stock market
Authors: Zhu Shuzhen , Wu Xiaofei , He Zhen , He Yining
Published: July 2021

Purpose

The purpose of this paper is to construct a frequency-domain framework to study the asymmetric spillover effects of international economic policy uncertainty on China’s stock market industry indexes.

Design/methodology/approach

This paper follows the time domain spillover model, asymmetric spillover model and frequency domain spillover model, which not only studies the degree of spillover in time domain but also studies the persistence of spillover effect in frequency domain.

Findings

It is found that China’s economic policy uncertainty plays a dominant role in the spillover effect on the stock market, while the global and US economic policy uncertainty is relatively weak. By decomposing realized volatility into quantified asymmetric risks of “good” volatility and “bad” volatility, it is concluded that economic policy uncertainty has a greater impact on stock downside risk than upside risk. For different time periods, the sensitivity of long-term and short-term spillover economic policy impact is different. Among them, asymmetric high-frequency spillover in the stock market is more easily observed, which provides certain reference significance for the stability of the financial market.

Originality/value

The originality aims at extending the traditional research paradigm of “time domain” to the research perspective of “frequency domain.” This study uses the more advanced models to analyze various factors from the static and dynamic levels, with a view to obtain reliable and robust research conclusions.
Failure analysis of delaminated carbon/epoxy composite under pure bending: validation with numerical analysis
Authors: Kopparthi Phaneendra Kumar , Gemaraju Srikar , Pathakokila Bhaskara Rao , Gamini Suresh
Published: July 2021

Purpose

Delamination is a common and crucial damage mode which occurs during manufacturing of layered composites or their service life. Its existence leads to degradation in mechanical properties or even structural failure of composites. Hence, the purpose of this article is to study the effect of induced delamination on flexural performance of CFRP composites.

Design/methodology/approach

In this article, the flexural behaviors of intact and delaminated carbon/epoxy laminates were investigated under pure bending. A circular PTFE film was introduced during fabrication to create artificial delamination. Moreover, finite element models were developed for intact and delaminated composites using ANSYS. The created models were discretized using 3D structural eight node solid elements.

Findings

The delamination influenced considerably flexural properties of composite. The composite exhibited a linear elastic nature prior to the damage of top ply on the compression side. The flexural strength and stiffness of the composite reduced to 44.5% and 18.2% respectively due to the existence of artificial delamination. The results of four point bending experiments and finite element analysis agreed for both intact and delaminated composites within acceptable error. Finally for same composites, first ply failure analysis was carried out using Tsai-Hill, Tsai-Wu and Hashin failure criteria.

Originality/value

In pure bending, beam section of the middle portion is free from shear. It is not so in case of three-point bending. Hence, the effect of embedded artificial defect on bending performance of CFRP composite due to pure bending has been investigated.
Acquired epidermodysplasia verruciformis or generalized verrucosis? A clinical and virological comparative study
Authors: Cheng Chun Yu , Lin Chiao‐Yun , Lai Chyong‐Huey , Chen Chun‐Bing , Chung Wen‐Hung
Published: July 2021

Few articles have described the difference between epidermodysplasia verruciformis (EV) and generalized verrucosis (GV). This study aimed to analyze the clinical findings and virology of the two diseases. The study enrolled patients diagnosed with EV and GV by clinical and histopathological findings. The demographic information, clinical manifestation, treatment, and therapeutic outcome were analyzed. All of the biopsy specimens of enrolled patients were sent for β‐human papillomavirus (HPV) DNA detection. A total of 13 cases were included in the present study, including five EV cases and eight GV cases. Legs and feet were significantly affected in GV cases (p = 0.035). All acquired EV cases had immunocompromised conditions, while only three GV cases could be identified as having an immunocompromised history. All EV cases were detected with β‐HPV infection, especially HPV5, but none of the GV cases were found to be infected with β‐HPV. The therapeutic response was refractory and often relapsed after discontinuation of treatment in both groups.
Functional diversity response to geographic and experimental precipitation gradients varies with plant community type
Authors: Zuo Xiaoan , Zhao Shenglong , Cheng Huan , Hu Ya , Wang Shaokun , Yue Ping , Liu Rentao , Knapp Alan K. , Smith Melinda D. , Yu Qiang , Koerner Sally E.
Published: July 2021

Precipitation is a primary determinant of plant community structure in drylands. However, the empirical evidence and predictions are lacking for how plant functional diversity in desert and steppe communities respond to altered precipitation regimes.

We examined how precipitation changes along the natural and experimental gradients affect different components of functional diversity in desert‐shrub and steppe‐grass communities. We compared the associations of precipitation changes with community‐weighted means (CWMs) of six traits, functional divergence (FDvar) of each single‐trait and multi‐trait functional richness (FRic) and dispersion (FDis) for shrub and grass communities along the natural and experimental gradients. We also disentangle the roles of species turnover and intraspecific variations in affecting the responses of different functional diversity to precipitation changes.

We found that in general, the similar responses of functional traits or diversity to both the natural and experimental precipitation gradients were dependent on plant community type. Across both two gradients, precipitation was positively associated with CWM of plant height and negatively associated with the CWM of SLA and leaf thickness in grass community, while positively associated with FDvar of four traits and FDis in shrub communities. Both species turnover and intraspecific variations contributed to the responses of grass community traits to precipitation changes across both two gradients, and to FDvar of traits and FDis in shrub community along the natural gradient. In contrast, species turnover variations contributed to FDvar of traits and FDis in shrub community in experiment.

These results suggest that there is better concordance between the effects of naturally and experimentally increased precipitation on functional diversity of plant communities, but different mechanisms behind the relationship of functional diversity–precipitation between shrub and grass communities. Grass communities can adapt to precipitation changes by average trait differences, while shrub communities persist through FDvar of single‐trait and multi‐trait dispersion, thus highlighting the important differences in adaptive strategies between shrub and grass communities. Our findings demonstrate that short‐term responses of plant communities to manipulative precipitation changes can reflect long‐term shifts at spatial scales depending on the specific functional trait and diversity.

A free Plain Language Summary can be found within the Supporting Information of this article.
Intraspecific correlations between growth and defence vary with resource availability and differ within and among populations
Authors: Hahn Philip G. , Keefover‐Ring Ken , Nguyen Linh M. N. , Maron John L.
Published: July 2021

A paradigm in the plant defence literature is that defending against herbivores comes at a cost to growth, resulting in a growth–defence trade‐off. However, while there is strong evidence for growth–defence trade‐offs across species, evidence is mixed within species.

Several mechanisms can account for this equivocal support within species, but teasing them apart requires examining growth–defence relationships both within and among populations, an approach seldom employed.

We examined correlations between plant biomass (growth) and terpene production (defence) within and among populations of Monarda fistulosa, a perennial herb. We sampled populations from Montana and Wisconsin, regions that differ in resource availability characterized by different summer precipitation and associated abiotic conditions that influence plant productivity.

We found negative, neutral and positive growth–defence correlations, depending on the scale examined. Negative correlations occurred across populations originating from divergent regions, positive correlations occurred across populations originating from within the high‐resource region and neutral correlations were found within single populations.

Collectively, these results challenge the general expectation of ubiquitous trade‐offs and support emerging views that resource availability (as it affects productivity) shapes the evolution of defence at different scales.

A free Plain Language Summary can be found within the Supporting Information of this article.
Glucocorticoid‐induced dose‐related and site‐specific bone remodelling, microstructure, and mechanical changes in cancellous and cortical bones
Authors: Chen Yan , Zhong Zhiguo , Chen Wenshuang , Lv Xiaohua , Luo Shi‐ying
Published: July 2021

The study investigated the effects of long‐term glucocorticoid (GC) administration on bone remodelling, microstructure, and biomechanical strength in cortical and cancellous (trabecular) bones. Thirty‐one female Sprague–Dawley rats were randomly divided into three dexamethasone (Dex) dosage groups, 1.0, 2.5, and 5.0 mg/kg twice a week for 8 weeks, and one control group treated with saline. At the end of the experiment, the tibia of one side and the fourth lumbar vertebrae were processed into sections for a histomorphometric analysis, while the femur of the same side and the fifth vertebrae were isolated for a biomechanical test. A dose‐dependent decline in bone formation was observed in both trabecular and cortical (periosteal and endosteal) bones. In contrast, bone resorption was inhibited only in cancellous bone in the two higher dose groups and not dose‐related. The ratio of Node/Termini increased, while marrow star volume (MSV) decreased in all Dex groups in metaphyseal trabecular bones, both of which were dose‐dependent. Subendosteal cortex porosity increased in parallel with non‐uniform trabecular distribution, but cortical thickness remained unchanged. Interestingly, there were no significant changes in microstructure or mechanical strength in lumbar trabecular bone. The cortical elastic load was dose‐independently reduced in all three Dex groups when compared with the control group. In summary, bone remodelling was dose‐dependently inhibited in cancellous bones but enhanced in intracortical bones. The non‐uniform distribution of trabecular bone and increased porosity in the inner edge of cortical bone were both in parallel with GC dosage, and the porosity increase was more likely to occur, leading to reduced cortical mechanical strength.