bluuebunny/crossref_metadata_2025 huggingface dataset:
Validation of a Pancreatic Cancer Detection Test in New-Onset Diabetes Using Cell-Free DNA 5-Hydroxymethylation Signatures
Authors: Haan David , Bergamaschi Anna , Guler Gulfem D , Friedl Verena , Ning Yuhong , Reggiardo Roman , Kesling Michael , Collins Micah , Gibb Bill , Pitea Adriana , Hazen Kyle , Bates Steve , Antoine Michael , Fraire Carolina , Lopez Vanessa , Malta Roger , Nabiyouni Maryam , Nguyen Albert , Phillips Tierney , Riviere Michael , Scott Aaron , Nilson Eric , Sheard Judy , Peters Melissa , Chowdhury Shimul , Volkmuth Wayne , Levy Samuel
Published: December 2021

BACKGROUND

Pancreatic cancer (PaC) has poor (10%) 5-year overall survival, largely due to predominant late-stage diagnosis. Patients with new-onset diabetes (NOD) are at a six-to eightfold increased risk for PaC. We developed a pancreatic cancer detection test for the use in a clinical setting that employs a logistic regression model based on 5-hydroxymethylcytosine (5hmC) profiling of cell-free DNA (cfDNA).

METHODS

cfDNA was isolated from plasma from 89 subjects with PaC and 596 case-control non-cancer subjects, and 5hmC libraries were generated and sequenced. These data coupled with machine-learning, were used to generate a predictive model for PaC detection, which was independently validated on 79 subjects with PaC, 163 non-cancer subjects, and 506 patients with non-PaC cancers.

RESULTS

The area under the receiver operating characteristic curve for PaC classification was 0.93 across the training data. Training sensitivity was 58.4% (95% confidence interval [CI]: 47.5– 68.6) after setting a classification probability threshold that resulted in 98% (95% CI: 96.5–99) specificity. The independent validation dataset sensitivity and specificity were 51.9% (95% CI: 40.4–63.3) and 100.0% (95% CI: 97.8–100.0), respectively. Early-stage (stage 1 and 2) PaC detection was 47.6% (95% CI: 23%–58%) and 39.4% (95% CI: 32%–64%) in the training and independent validation datasets, respectively. Sensitivity and specificity in NOD patients were 55.2% [95% CI: 35.7–73.6] and 98.4% [95% CI: 91.3–100.0], respectively. The PaC signal was identified in intraductal papillary mucinous neoplasm (64%), pancreatitis (56%), and non-PaC cancers (17%).

CONCLUSIONS

The pancreatic cancer detection assay showed robust performance in the tested cohorts and carries the promise of becoming an essential clinical tool to enable early detection in high-risk NOD patients.
Control Strategies for the Third wave of COVID-19 infection in India: A Mathematical Model Incorporating Vaccine Effectiveness
Authors: Sivadas Namitha A , Panda Pooja , Mahajan Ashutosh
Published: December 2021

The waning effectiveness of the COVID-19 vaccines and the emergence of a new variant Omicron has given rise to the possibility of another outbreak of the infection in India. COVID-19 has caused more than 34 million reported cases and 475 thousand deaths in India so far, and it has affected the country at the root level, socially as well as economically. After going through different control measures, mass vaccination has been achieved to a large extent for the highly populous country, and currently under progress. India has already been hit by a massive second wave of infection in April-June, 2021 mainly due to the delta variant, and might see a third wave in the near future that needs to be controlled with effective control strategies. In this paper, we present a compartmental epidemiological model with vaccinations incorporating the dose-dependent effectiveness. We study a possible sudden outbreak of SARS-CoV2 variants in the future, and bring out the associated predictions for various vaccination rates and point out optimum control measures. Our results show that for transmission rate 30% higher than the current rate due to emergence of new variant or relaxation of social distancing conditions, daily new cases can peak to 250k in March 2022, taking the second dose effectiveness dropping to 50% in the future. Combination of vaccination and controlled lockdown or social distancing is the key to tackling the current situation and for the coming few months. Our simulation results show that social distancing measures show better control over the disease spread than the higher vaccination rates.
Functional properties of the spike glycoprotein of the emerging SARS-CoV-2 variant B.1.1.529
Authors: Wang Qian , Anang Saumya , Iketani Sho , Guo Yicheng , Liu Lihong , Ho David D. , Sodroski Joseph G.
Published: December 2021

The recently emerged B.1.1.529 (Omicron) SARS-CoV-2 variant has a highly divergent spike (S) glycoprotein. We compared the functional properties of B.1.1.529 S with those of previous globally prevalent SARS-CoV-2 variants, D614G and B.1.617.2. Relative to these variants, B.1.1.529 S exhibits decreased processing, resulting in less efficient syncytium formation and lower S incorporation into virus particles. Nonetheless, B.1.1.529 S supports virus infection equivalently. B.1.1.529 and B.1.617.2 S glycoproteins bind ACE2 with higher affinity than D614G S. The unliganded B.1.1.529 S trimer is less stable at low temperatures than the other SARS-CoV-2 spikes, a property related to spike conformation. Upon ACE2 binding, the B.1.1.529 S trimer sheds S1 at 37 degrees but not at 0 degrees C. B.1.1.529 pseudoviruses are relatively resistant to neutralization by sera from convalescent COVID-19 patients and vaccinees. These properties of the B.1.1.529 spike glycoprotein likely influence the transmission, cytopathic effects and immune evasion of this emerging variant.
A novel assessment method for COVID-19 humoral immunity duration using serial measurements in naturally infected and vaccinated subjects
Authors: de Boer Jasper , Saade Ursula , Granjon Elodie , Trouillet-Assant Sophie , Saade Carla , Pottel Hans , Zrein Maan
Published: December 2021

Background

It is crucial for medical decision-making and vaccination strategies to collect information on sustainability of immune responses after infection or vaccination, and how long-lasting antibodies against SARS-COV-2 could provide a humoral and protective immunity, preventing reinfection with SARS-CoV-2 or its variants. The aim of this study is to present a novel method to quantitatively measure and monitor the diversity of SARS-CoV-2 specific antibody profiles over time.

Methods

Two collections of serum samples were used in this study: A collection from 20 naturally infected subjects (follow-ups to 1 year) and a collection from 83 subjects vaccinated with one or two doses of Pfizer BioNtech vaccine (BNT162b2/BNT162b2) (follow-ups to 6 months). The Multi-SARS-CoV-2 assay, a multiparameter serology test, developed for the serological confirmation of past-infections was used to determine the reactivity of six different SARS-CoV-2 antigens. For each patient sample, 3 dilutions (1/50, 1/400 and 1/3200) were defined as an optimal set over the six antigens and their respective linear ranges, allowing accurate quantitation of the corresponding six specific antibodies. Nonlinear mixed-effects modelling was applied to convert intensity readings from 3 determined dilutions to a single quantification value for each antibody.

Results

Median half-life for the 20 naturally infected vs 74 vaccinated subjects (two doses) was respectively 120 vs 50 days for RBD, 127 vs 53 days for S1 and 187 vs 86 days for S2 antibodies. Respectively, 90% of the antibody concentration wanes after 398 vs 158 days for RBD, 420 vs 171 days for S1, and 620 vs 225 days for S2 after the second vaccine shot.

Conclusion

The newly proposed method, based on a series of a limited number of dilutions, can convert a conventional qualitative assay into a quantitative assay. This conversion helps define the sustainability of specific immune responses against each relevant viral antigen and can help in defining the protection characteristics after an infection or a vaccination.
A Novel CRISPR-Engineered, Stem Cell-Derived Cellular Vaccine
Authors: Chakraborty Krishnendu , Chandrashekar Abishek , Sidaway Adam , Latta Elizabeth , Yu Jingyou , McMahan Katherine , Giffin Victoria , Manickam Cordelia , Kroll Kyle , Mosher Matthew , Reeves R. Keith , Gam Rihab , Arthofer Elisa , Choudhry Modassir , Barouch Dan H , Henley Tom
Published: December 2021

COVID-19 has forced rapid clinical translation of novel vaccine technologies, principally mRNA vaccines, that have resulted in meaningful efficacy and adequate safety in response to the global pandemic. Notwithstanding this success, there remains an opportunity for innovation in vaccine technology to address current limitations and meet the challenges of inevitable future pandemics. We describe a universal vaccine cell (UVC) rationally designed to mimic the natural physiologic immunity induced post viral infection of host cells. Induced pluripotent stem cells were CRISPR engineered to delete MHC-I expression and simultaneously overexpress a NK Ligand adjuvant to increase rapid cellular apoptosis which was hypothesized to enhance viral antigen presentation in the resulting immune microenvironment leading to a protective immune response. Cells were further engineered to express the parental variant WA1/2020 SARS-CoV-2 spike protein as a representative viral antigen prior to irradiation and cryopreservation. The cellular vaccine was then used to immunize non-human primates in a standard 2-dose, IM injected prime + boost vaccination with 1e8 cells per 1 ml dose resulting in robust neutralizing antibody responses (1e3 nAb titers) with decreasing levels at 6 months duration. Similar titers generated in this established NHP model have translated into protective human neutralizing antibody levels in SARS-Cov-2 vaccinated individuals. Animals vaccinated with WA1/2020 spike antigens were subsequently challenged with 1.0 × 105TCID50infectious Delta (B.1.617.2) SARS-CoV-2 in a heterologous challenge which resulted in an approximately 3-log order decrease in viral RNA load in the lungs. These heterologous viral challenge results reflect the ongoing real-world experience of original variant WA1/2020 spike antigen vaccinated populations exposed to rapidly emerging variants like Delta and now Omicron. This cellular vaccine is designed to be a rapidly scalable cell line with a modular poly-antigenic payload to allow for practical, large-scale clinical manufacturing and use in an evolving viral variant environment. Human clinical translation of the UVC is being actively explored for this and potential future pandemics.
A high-throughput 3D bioprinted cancer cell migration and invasion model with versatile and broad biological applicability
Authors: Jung MoonSun , Skhinas Joanna N. , Du Eric Y. , Tolentino M.A. Kristine , Utama Robert H. , Engel Martin , Volkerling Alexander , Sexton Andrew , O’Mahony Aidan P. , Ribeiro Julio C. C. , Gooding J. Justin , Kavallaris Maria
Published: December 2021

Understanding the underlying mechanisms of migration and metastasis is a key focus of cancer research. There is an urgent need to developin vitro3D tumor models that can mimic physiological cell-cell and cell-extracellular matrix interactions, with high reproducibility and that are suitable for high throughput (HTP) drug screening. Here, we developed a HTP 3D bioprinted migration model using a bespoke drop-on-demand bioprinting platform. This HTP platform coupled with tunable hydrogel systems enables (i) the rapid encapsulation of cancer cells withinin vivotumor mimicking matrices, (ii)in situand real-time measurement of cell movement, (iii) detailed molecular analysis for the study of mechanisms underlying cell migration and invasion, and (iv) the identification of novel therapeutic options. This work demonstrates that this HTP 3D bioprinted cell migration platform has broad applications across quantitative cell and cancer biology as well as drug screening.
Pipeline for retrieval of COVID-19 immune signatures
Authors: Newton Adam J.H. , Chartash David , Kleinstein Steven H. , McDougal Robert A.
Published: December 2021

Objective

The accelerating pace of biomedical publication has made retrieving papers and extracting specific comprehensive scientific information a key challenge. A timely example of such a challenge is to retrieve the subset of papers that report on immune signatures (coherent sets of biomarkers) to understand the immune response mechanisms which drive differential SARS-CoV-2 infection outcomes. A systematic and scalable approach is needed to identify and extract COVID-19 immune signatures in a structured and machine-readable format.

Materials and Methods

We used SPECTER embeddings with SVM classifiers to automatically identify papers containing immune signatures. A generic web platform was used to manually screen papers and allow anonymous submission.

Results

We demonstrate a classifier that retrieves papers with human COVID-19 immune signatures with a positive predictive value of 86%. Semi-automated queries to the corresponding authors of these publications requesting signature information achieved a 31% response rate. This demonstrates the efficacy of using a SVM classifier with document embeddings of the abstract and title, to retrieve papers with scientifically salient information, even when that information is rarely present in the abstract. Additionally, classification based on the embeddings identified the type of immune signature (e.g., gene expression vs. other types of profiling) with a positive predictive value of 74%.

Conclusion

Coupling a classifier based on document embeddings with direct author engagement offers a promising pathway to build a semistructured representation of scientifically relevant information. Through this approach, partially automated literature mining can help rapidly create semistructured knowledge repositories for automatic analysis of emerging health threats.
Copper imbalance linked to oxidative stress and cell death during Zika virus infection in human astrocytes
Authors: Puig-Pijuan Teresa , Souza Leticia R. Q. , Pedrosa Carolina da S. G. , Higa Luiza M. , Monteiro Fabio Luis , Tanuri Amilcar , Valverde Rafael H. F. , Einicker-Lamas Marcelo , Rehen Stevens Kastrup
Published: December 2021

The Zika virus (ZIKV) caused neurological abnormalities in more than 3500 Brazilian newborns between 2015 and 2020. Data have pointed to oxidative stress in astrocytes as well as to dysregulations in neural cell proliferation and cell cycle as important events accounting for the cell death and neurological complications observed in Congenital Zika Syndrome. Copper imbalance has been shown to induce similar alterations in other pathologies, and disturbances in copper homeostasis have already been described in viral infections. For this reason, we investigated copper homeostasis imbalance as a factor that could contribute to the cytotoxic effects of ZIKV infection in iPSC-derived human astrocytes. Our results show that ZIKV infection leads to a downregulation of one of the transporters mediating copper release, ATP7B protein. We also observed the activation of mechanisms that counteract high copper levels, including the synthesis of copper chaperones and the reduction of the copper importer protein CTR1. Finally, we show that chelator-mediated copper sequestration in ZIKV-infected astrocytes reduces the levels of reactive oxygen species and improves cell viability, but does not change the overall percentage of infected cells. In summary, our results show that copper homeostasis imbalance plays a role in the pathology of ZIKV in astrocytes, indicating that it may also be a factor accounting for the developmental abnormalities in the central nervous system following viral infection. Evaluating micronutrient levels and the use of copper chelators in pregnant women susceptible to ZIKV infection may be promising strategies to manage novel cases of congenital ZIKV syndrome.
Genome-wide identification and expression analysis of the invertase gene family in common wheat (Triticum aestivum L.)
Authors: Wang Chao , Wang Guanghao , Qu Xiaojian , Zhang Xiangyu , Deng Pingchuan , Ji Wanquan , Zhang Hong
Published: December 2021

Background

The degradation of sucrose plays an important role in the process of crop biomass allocation and yield formation. Invertase (INV) irreversibly catalyzes the conversion of sucrose into glucose and fructose, which doomed its’ important role in plant development and stress tolerance. However, the functions of INV genes in wheat, one of the most important crops, were less studied due to the polyploidy.

Results

Here, we systematically analyzed the INV gene family based on the latest published wheat reference genomic information. A total of 126 TaINV genes were identified and classified into three classes based on the phylogenetic relationship and their gene structure. Of which, 11 and 83 gene pairs were identified as tandem and segmental duplication genes respectively, while the Ka/Ks ratios of tandem and segmental duplication TaINV genes were less than 1. Expression profile analysis shows that 18 TaINV genes have tissue-specific expression, and 54 TaINV genes were involved in stress response. Furthermore, RNA-seq showed that 35 genes are differentially expressed in grain weight NILs N0910-81L/N0910-81S, in which 9 TaINVs were stably detected by qRT-PCR at three time-points, 4, 7 and 10 DPA. Four of them (TaCWI47, TaCWI48, TaCWI50 and TaVI27) different expressed between the NILs resided in 4 QTL segments (QTGW.nwafu-5DL.1, QTGW.nwafu-5DL.2, QTGW.nwafu-7AS.1 and QTGW.nwafu-7AS.2). These findings facilitate function investigations of the wheat INV gene family and provide new insights into the grain development mechanism in wheat.

Conclusions

Our results showed that allopolyploid events were the main reason for the expansion of the TaINV gene family in hexaploid wheat, and duplication genes might undergo purifying selection. The expression profiling of TaINV genes implied that they are likely to play an important role in wheat growth and development and adaption to stressful environments. And TaCWI47, TaCWI48, TaCWI50 and TaVI27 may have more important roles in grain developments. Our study lay a base for further dissecting the functional characterization of TaINV family members.
Vein fate determined by flow-based but time-delayed integration of network architecture
Authors: Marbach Sophie , Ziethen Noah , Bastin Leonie , Bäuerle Felix K. , Alim Karen
Published: December 2021

Veins in vascular networks, such as in blood vasculature or leaf networks, continuously reorganize, grow or shrink, to minimize energy dissipation. Flow shear stress on vein walls has been set forth as the local driver for a vein’s continuous adaptation. Yet, shear feedback alone cannot account for the observed diversity of vein dynamics – a puzzle made harder by scarce spatiotemporal data. Here, we resolve network-wide vein dynamics and shear rate during spontaneous reorganization in the prototypical vascular networks ofPhysarum polycephalum. Our experiments reveal a plethora of vein dynamics (stable, growing, shrinking) where the role of shear is ambiguous. Quantitative analysis of our data reveals that (a) shear rate indeed feeds back on vein radius, yet, with a time delay of 1 — 3 min. Further, we reconcile the experimentally observed disparate vein fates by developing a model for vein adaptation within a network and accounting for the observed time delay. The model reveals that (b) vein fate is determined by parameters – local pressure or relative vein resistance – which integrate the entire network’s architecture, as they result from global conservation of fluid volume. Finally, we observe avalanches of network reorganization events that cause entire clusters of veins to vanish. Such avalanches are consistent with network architecture integrating parameters governing vein fate as vein connections continuously change. As the network architecture integrating parameters intrinsically arise from laminar fluid flow in veins, we expect our findings to play a role across flow-based vascular networks.
The rich-to-poor vaccine donation game: When will self-interested countries donate their surplus vaccines during pandemics?
Authors: Lampert Adam , Sulitzeanu-Kenan Raanan , Vanhuysse Pieter , Tepe Markus
Published: December 2021

When will self-interested vaccine-rich countries voluntarily donate their surplus vaccines to vaccine-poor countries during a pandemic? We develop a game-theoretic approach to address this question. We identify vaccine-rich countries’ optimal surplus donation strategies, and then examine whether these strategies are stable (Nash equilibrium or self-enforcing international agreement). We identify parameter ranges in which full or partial surplus stock donations are optimal for the donor countries. Within a more restrictive parameter region, these optimal strategies are also stable. This implies that, under certain conditions (notably a total amount of surplus vaccines that is sufficiently large), simple coordination can lead to significant donations by strictly self-interested vaccine-rich countries. On the other hand, if the total amount that the countries can donate is small, we expect no contribution from self-interested countries. The results of this analysis provide guidance to policy makers in identifying the circumstances in which coordination efforts are likely to be effective.
Single-cell monitoring of dry mass and dry density reveals exocytosis of cellular dry contents in mitosis
Authors: Miettinen Teemu P. , Ly Kevin S. , Lam Alice , Manalis Scott R.
Published: December 2021

Cell mass and composition change with cell cycle progression. Our previous work characterized buoyant mass accumulation dynamics in mitosis (Miettinen et al., 2019), but how dry mass and cell composition change in mitosis has remained unclear. To better understand mitotic cell growth and compositional changes, we develop a single-cell approach for monitoring dry mass and the density of that dry mass every ∼75 seconds with 1.3% and 0.3% measurement precision, respectively. We find that suspension grown mammalian cells lose dry mass and increase dry density following mitotic entry. These changes display large, non-genetic cell-to-cell variability, and the changes are reversed at metaphase-anaphase transition, after which dry mass continues accumulating. The change in dry density causes buoyant and dry mass to differ specifically in early mitosis, thus reconciling existing literature on mitotic cell growth. Mechanistically, the dry composition changes do not require mitotic cell swelling or elongation. Instead, cells in early mitosis increase lysosomal exocytosis, and inhibition of exocytosis prevents the dry composition from changing. Overall, our work provides a new approach for monitoring single-cell dry mass and composition and reveals that mitosis is coupled to extensive exocytosis-mediated secretion of cellular contents.
Broad neutralization of SARS-CoV-2 variants by an inhalable bispecific single-domain antibody
Authors: Li Cheng , Zhan Wuqiang , Yang Zhenlin , Tu Chao , Zhu Yuanfei , Song Wenping , Huang Keke , Gu Xiaodan , Kong Yu , Zhang Xiang , Zhang Meng , Zhang Yi , Xie Youhua , Deng Qiang , Chen Zhenguo , Lu Lu , Jiang Shibo , Sun Lei , Wu Yanling , Ying Tianlei
Published: December 2021

The effectiveness of SARS-CoV-2 vaccines and therapeutic antibodies has been limited by the continuous emergence of viral variants, and by the restricted diffusion of antibodies from circulation into the sites of respiratory virus infection. Here, we report the identification of two highly conserved regions on Omicron variant RBD recognized by broadly neutralizing antibodies. Based on this finding, we generated a bispecific single-domain antibody that was able to simultaneously and synergistically bind these two regions on a single Omicron variant RBD as revealed by Cryo-EM structures. This inhalable antibody exhibited exquisite neutralization breadth and therapeutic efficacy in mouse models of SARS-CoV-2 infections. The structures also deciphered an uncommon cryptic epitope within the spike trimeric interface that may have implications for the design of broadly protective SARS-CoV-2 vaccines and therapeutics.
The Zip4 protein directly couples meiotic crossover formation to synaptonemal complex assembly
Authors: Pyatnitskaya Alexandra , Andreani Jessica , Guérois Raphaël , De Muyt Arnaud , Borde Valérie
Published: December 2021

Meiotic recombination is triggered by programmed double-strand breaks (DSBs), a subset of these being repaired as crossovers, promoted by eight evolutionarily conserved proteins, named ZMM. Crossover formation is functionally linked to synaptonemal complex (SC) assembly between homologous chromosomes, but the underlying mechanism is unknown. Here we show that Ecm11, a SC central element protein, localizes on both DSB sites and sites that attach chromatin loops to the chromosome axis, which are the starting points of SC formation, in a way that strictly requires the ZMM protein Zip4. Furthermore, Zip4 directly interacts with Ecm11, and point mutants that specifically abolish this interaction lose Ecm11 binding to chromosomes and exhibit defective SC assembly. This can be partially rescued by artificially tethering interaction-defective Ecm11 to Zip4. Mechanistically, this direct connection ensuring SC assembly from CO sites could be a way for the meiotic cell to shut down further DSB formation once enough recombination sites have been selected for crossovers, thereby preventing excess crossovers. Finally, the mammalian ortholog of Zip4, TEX11, also interacts with the SC central element TEX12, suggesting a general mechanism.
Transcription factor-mediated intestinal metaplasia and the role of a shadow enhancer
Authors: Singh Harshabad , Seruggia Davide , Madha Shariq , Saxena Madhurima , Nagaraja Ankur K. , Wu Zhong , Zhou Jin , Huebner Aaron J. , Maglieri Adrianna , Wezenbeek Juliette , Hochedlinger Konrad , Orkin Stuart H. , Bass Adam J. , Hornick Jason L. , Shivdasani Ramesh A.
Published: December 2021

Barrett's esophagus (BE) and gastric intestinal metaplasia are related premalignant conditions in which areas of human stomach epithelium express mixed gastric and intestinal features. Intestinal transcription factors (TFs) are expressed in both conditions, with unclear causal roles andcis-regulatory mechanisms. Ectopic CDX2 reprogrammed isogenic mouse stomach organoid lines to a hybrid stomach–intestinal state transcriptionally similar to clinical metaplasia; squamous esophageal organoids resisted this CDX2-mediated effect. Reprogramming was associated with induced activity at thousands of previously inaccessible intestine-restricted enhancers, where CDX2 occupied DNA directly. HNF4A, a TF recently implicated in BE pathogenesis, induced weaker intestinalization by binding a novel shadowCdx2enhancer and hence activatingCdx2expression. CRISPR/Cas9-mediated germline deletion of thatcis-element demonstrated its requirement inCdx2induction and in the resulting activation of intestinal genes in stomach cells. dCas9-conjugated KRAB repression mapped this activity to the shadow enhancer's HNF4A binding site. Altogether, we show extensive but selective recruitment of intestinal enhancers by CDX2 in gastric cells and that HNF4A-mediated ectopic CDX2 expression in the stomach occurs through a conserved shadowcis-element. These findings identify mechanisms for TF-driven intestinal metaplasia and a likely pathogenic TF hierarchy.
The transition toward the business formality of the Peruvian MSEs: How does the perception of entrepreneurs and the sector influence?
Authors: Silupu Brenda , Usero Belen , Montoro-Sánchez Ángeles
Published: December 2021

Purpose

The formalization of a company is a process that requires compliance with standards established by government institutions. In developing countries, many businesses start this process, but do not finish it, with different levels of formality. The objective of this research is to analyze how the perception of entrepreneurs about bureaucratic procedures and the sector determine the level of formality regarding an established company that has taken the first step to formality.

Design/methodology/approach

The National Survey of Micro and Small Enterprises (MSEs) is used with a sample of 4,619 Peruvian MSEs with more than three years of operation within the manufacturing and services sector. The data are analyzed with the ordered logistic regression technique.

Findings

The results show that the more favorable the perception of entrepreneurs about the ease of bureaucratic procedures, the higher the level of business formality; and companies in the manufacturing sector are less formal than those in the services sector. In addition, the perceptions of entrepreneurs positively moderate the level of formality in the case of companies in the manufacturing sector.

Originality/value

Levels of formality in established companies are analyzed, defined by the compliance degree with the requirements to be a formal company. The literature on business informality in emerging countries is expanded, particularly in Latin America, incorporating the analysis of the formalization process.
Entrepreneurial leadership and employee innovative behavior in the software development firms: do employees' epistemic curiosity and creative process engagement matter?
Authors: Khan Muhammad Awais
Published: December 2021

Purpose

Building on self-determination theory, this study empirically examined the influence of entrepreneurial leadership (EL) style on employee innovative behavior (EIB) in the context of software development firms located in the twin cities of Pakistan (Rawalpindi and Islamabad).

Design/methodology/approach

For the present study, an employee survey (online questionnaire) was used for data collection. The data were collected through an adopted questionnaire by using emails and messaging applications. Structural Equation Modeling (PLS-SEM) was used to analyze data collected from 245 respondents.

Findings

The findings of this study delineate that entrepreneurial leadership positively and significantly influences employee innovative behavior. Moreover, the relationship between entrepreneurial leadership and employee innovative behavior was partially mediated by employee epistemic curiosity (EC) and creative process engagement (CPE). The sequential mediation by the employee epistemic curiosity and creative process engagement between the link of entrepreneurial leadership and employee innovative behavior was also confirmed.

Practical implications

In innovation-intensive organizations like software development firms, entrepreneurial leadership style can foster employee innovative behavior that is critical for organizational innovation success. This study provides information to the strategic leaders on how leadership behaviors can drive employee innovative behavior, particularly in the context of software development companies.

Originality/value

This study is an attempt to extend the scarce literature on the mechanisms through which leadership styles impact employee innovative behavior. Specifically, the mediating roles of employee epistemic curiosity and creative process engagement have been explored through a self-determination perspective.
Comparative study on performance of different artificial neural network methods for prediction of the Covid19
Authors: Sedighi Fard Alireza
Published: December 2021

Purpose

This study aims to compare many artificial neural network (ANN) methods to find out which method is better for the prediction of Covid19 number of cases in N steps ahead of the current time. Therefore, the authors can be more ready for similar issues in the future.

Design/methodology/approach

The authors are going to use many ANNs in this study including, five different long short-term memory (LSTM) methods, polynomial regression (from degree 2 to 5) and online dynamic unsupervised feedforward neural network (ODUFFNN). The authors are going to use these networks over a data set of Covid19 number of cases gathered by World Health Organization. After 1,000 epochs for each network, the authors are going to calculate the accuracy of each network, to be able to compare these networks by their performance and choose the best method for the prediction of Covid19.

Findings

The authors concluded that for most of the cases LSTM could predict Covid19 cases with an accuracy of more than 85% after LSTM networks ODUFFNN had medium accuracy of 45% but this network is highly flexible and fast computing. The authors concluded that polynomial regression cant is a good method for the specific purpose.

Originality/value

Considering the fact that Covid19 is a new global issue, less studies have been conducted with a comparative approach toward the prediction of Covid19 using ANN methods to introduce the best model of the prediction of this virus.
Analysing the impact of artificial intelligence on the competitiveness of tourism firms: a modified total interpretive structural modeling (m-TISM) approach
Authors: Sharma Kamakshi , Jain Mahima , Dhir Sanjay
Published: December 2021

Purpose

This study explores the variables that drive the impact of artificial intelligence (AI) on the competitiveness of a tourism firm. The relationship between the variables is established using the modified total interpretive structural modelling (m-TISM) methodology. The factors are identified through literature review and expert opinion. This study investigates the hierarchical relationship between these variables.

Design/methodology/approach

The modified total interpretive structural modelling (m-TISM) method is used to develop a hierarchical interrelationship among variables that display direct and indirect impact. The competitiveness of a tourism firm is measured by investigating the effect of variables on the firm's financial performance.

Findings

The study identifies ten key factors essential for analysing the impact of AI on a firm's competitiveness. The m-TISM methodology gave us the hierarchical relationship between the factors and their interpretation. A theoretical TISM model has been constructed based on the hierarchy and relationship of the elements. The elements that fall in Level V are “AI Skilled Workforce”, “Infrastructure” and “Policies and Regulations”. Level IV includes the elements “AI Readiness”, “AI-Enabled Technologies” and “Digital Platforms”. Elements that fall under Level III are “Productivity” and “AI Innovation”. Level II and Level I comprise “Tourist Satisfaction” and “Financial Performance”, respectively. The levels indicate the elements' hierarchical level, with Level I the highest and Level V the lowest.

Research limitations/implications

Tourism and AI scholars can analyse the given variables by including the transitive links and incorporate new variables depending upon future research. The m-TISM model constructed from literature review and expert opinion can act as a theoretical base for future studies to be conducted by researchers.

Practical implications

Management/Practitioners can focus on the available characteristics and capitalise on them while working on the factors lacking in their organisation to enhance their competitiveness. Entrepreneurs starting their own business can utilise the elements in understanding the ecosystem of strengthening a firm's competitiveness. They can work to improve on the aspects which are crucial and trigger the impact on competitiveness. The government and management can devise policies and strategies that encompass the essential factors that positively impact the competitiveness of the firms. The approach can then be looked at with a holistic approach to cater to the other related components of the tourism industry.

Originality/value

This study is the first of its kind to use the modified TISM methodology to understand the impact of AI on the competitiveness of tourism firms.
Geometric imperfect preventive maintenance and replacement (GIPMAR) model for aging repairable systems
Authors: Udoh Nse , Effanga Effanga
Published: December 2021

Purpose

This work seeks to develop a geometric imperfect preventive maintenance (PM) and replacement model (GIPMAR) for aging repairable systems due to age and prolong usage that would meet users need in three phases: within average life span, beyond average life span and beyond initial replacement age of system.

Design/methodology/approach

The authors utilized the geometric process (GP) as the hazard function to characterize the increasing failure rate (IFR) of the system. The GP hazard function was incorporated into the hybridized preventive and replacement model of Lin et al. (2000). The resultant expected cost rate function was optimized to obtain optimum intervals for PM/replacement and required numbers of PM per cycle. The proposed GIPMAR model was applied to repairable systems characterized by Weibull life function and the results yielded PM/replacement schedules for three different phases of system operation.

Findings

The proposed GIPMAR model is a generalization of Lin et al. (2000) PM model that were comparable with results of earlier models and is adaptive to situations in developing countries where systems are used across the three phases of operation depicted in this work. This may be due to economic hardship and operating environment.

Practical implications

The proposed model has provided PM/Replacement schedules for different phases of operation which was never considered. This would provide a useful guide to maintenance engineers and end-users in developing countries with a view to minimizing the average cost of maintenance as well as reducing the number of down times of systems.

Social implications

A duly implemented GIPMAR model would ensure efficient operation of systems, optimum man-hour need in the organization and guarantee customer's goodwill in a competitive environment.

Originality/value

In this work, the authors have extended Lin et al. (2000) PM model to provide PM/replacement schedules for aging repairable systems which was not provided for in earlier existing models and literature.
Low friction bio-inspired polydopamine/polytetrafluoroethylene coating performance in hydrodynamic bearings
Authors: Rutkevičius Marius , Dong Jimmy , Tremelling Darren , Viertel Julia , Beckford Samuel
Published: December 2021

Purpose

Low friction polymer coatings able to withstand high loadings and many years of continuous operation are difficult to formulate at low cost, but could find many applications in industry. This study aims to analyze and compare friction and wear performance of novel polydopamine/polytetrafluoroethylene (PDA/PTFE) and traditional tin Babbitt coatings applied to an industrial journal bearing.

Design/methodology/approach

This paper tested PTFE based coating, co-deposited with PDA, a biopolymer allowing sea mussels to adhere to ocean rocks. This coating was deposited on flat steel substrates and on a curved cast iron hydrodynamic journal bearing surface. The flat substrates were analyzed with a tribometer and an optical microscope, while the coated bearing liners were tested in an industrial laboratory setting at different speeds and different radial loads.

Findings

PDA/PTFE coating showed 2-3 times lower friction compared to traditional tin Babbitt for flat substrates, but higher friction in the bearing liners. PDA/PTFE also showed considerable wear through coating delamination and abrasion in the bearing liners.

Research limitations/implications

Five future modifications to mitigate coating flaws are provided, which include modifications to coating thickness and its surface finish.

Originality/value

While the novel coating showed excellent results on flat substrates, coating performance in a large scale bearing was found to be poor. This study shows that coating preparation needs to be improved to avoid frictional losses and unwanted damage to bearings. We provide several routes that could improve coating performance in industrial applications.
Fractal model of thermal contact conductance of two spherical joint surfaces considering friction coefficient
Authors: Sun Xianguang , Meng Chunxiao , Duan Tiantang
Published: December 2021

Purpose

The purpose of this study is to propose a fractal model of thermal contact conductance (TCC) of two spherical joint surfaces, considering friction coefficient based on the three-dimensional fractal theory.

Design/methodology/approach

The effects of friction coefficient, fractal parameters, radius of curvature and contact type on TCC were analyzed using numerical simulation.

Findings

The results indicate that the TCC decreases with the increase of friction coefficient and fractal roughness and increases with the increase of fractal dimension and radius of curvature; the contact type of two spherical joint surfaces has an important influence on the TCC, and the TCC of external contact is smaller than that of internal contact under the same contact load.

Originality/value

A fractal model of TCC of two spherical joint surfaces considering friction coefficient is proposed in this paper. Achievements of this work provide some theoretical basis for the research of TCC of bearings and other curved surfaces.
Macroeconomic impacts of fiscal shocks on the Moroccan economy: a disaggregated SVAR analysis
Authors: Alami Youssef , El Idrissi Issam , Bousselhami Ahmed , Raouf Radouane , Boujettou Hassane
Published: December 2021

Purpose

The present paper aims to evaluate the structural impact of exogenously induced fiscal shocks on the Moroccan economy. This entails an analysis of the effect on the GDP of COVID-19-induced fiscal shocks manifesting in terms of budgetary revenues and expenditures. A key aspect of this analysis addresses the size of the tax and fiscal multipliers.

Design/methodology/approach

The study examines the structural relationship between five variables during the period between Q1 2009 and Q2 2020 using an SVAR approach that allows for a dynamic interaction between ordinary expenditures and revenues on a quarterly basis.

Findings

Positive structural shocks on public spending are likely to negatively impact economic growth. Negative economic growth, in turn, will damage price levels and interest rates, mainly over the long term. However, public-revenue-multiplier-associated shocks exceed these price- and interest-rate multiplier-associated shocks. Indeed, a structural shock to ordinary revenues can have a positive but insignificant impact on the GDP stemming from the ensuing decrease in the government budget deficit that proceeds from the increase in government revenues.

Originality/value

This is one of the first studies in the Moroccan context to assess the impact of the current worldwide pandemic on public finances. In addition, this study highlights the importance of boosting economic recovery through public spending.
Innovational duality and sustainable development: finding optima amidst socio-ecological policy trade-off in post-COVID-19 era
Authors: Sinha Avik , Adhikari Arnab , Jha Ashish Kumar
Published: December 2021

Purpose

This study aims to analyze the socio-ecological policy trade-off caused by technological innovations in the post-COVID-19 era. The study outcomes are utilized to design a comprehensive policy framework for attaining sustainable development goals (SDGs).

Design/methodology/approach

Study is done for 100 countries over 1991–2019. Second-generation estimation method is used. Innovation is measured by total factor productivity, environmental quality is measured by carbon dioxide (CO2) emissions and social dimension is captured by unemployment.

Findings

Innovation–CO2 emissions association is found to be inverted U-shaped and innovation–unemployment association is found to be U-shaped.

Research limitations/implications

The study outcomes show the conflicting impact of technological innovation leading to policy trade-off. This dual impact of innovation is considered during policy recommendation.

Practical implications

The policy framework recommended in the study shows a way to address the objectives of SDG 8, 9 and 13 during post-COVID-19 period.

Social implications

Policy recommendations in the study show a way to internalize the negative social externality exerted by innovation.

Originality/value

This study contributes to the literature by considering the policy trade-off caused by innovation and recommending an SDG-oriented policy framework for the post-COVID-19 era.
Research data stewardship at the University of Hong Kong
Authors: Xiao SiZhe , Ng Tsz Yan , Yang Tao T.
Published: December 2021

Purpose

The purpose of this paper is to look at the journey and experience of the University of Hong Kong (HKU) Research Data Management (RDM) practice to respond to the needs of researchers in an academic library.

Design/methodology/approach

The research data services (RDS) practice is based on the FAIR data principle. And the authors designed the RDM Stewardship framework to implement the RDS step by step.

Findings

The HKU Libraries developed and implemented a set of RDS under a research data stewardship framework in response to the recent evolving research needs for RDM amongst the academic communities. The services cover policy and procedure settings for research data planning, research data infrastructure establishment, data curation services and provision of online resources and instructional guidelines.

Originality/value

This study provides an example of an approach to respond to the needs of the academic libraries about how to start the RDS including the data policy, data repository, data librarianship and data curation.
Intellectual landscape of research on change management: a bibliometric analysis
Authors: Moosa Visal , Khalid Abdul Hafeez , Mohamed Ahmed
Published: December 2021

Purpose

This study aims to illustrate an overarching picture of the knowledge base on change management, including contributing authors, institutions and countries. The study also aims to elicit the intellectual structure of the knowledge base using science mapping.

Design/methodology/approach

The authors engaged 1,457 published documents, generated from a SCOPUS search, to analyse research conducted in the area of change management. Bibliometric indicators such as authors, institutions and countries were used in the analysis. Additionally, science mapping analyses such as keyword co-occurrence and co-citation were also performed using VOSviewer.

Findings

The findings indicated that scholarly work in the field of change management is on the rise. Furthermore, while the contribution from different regions of the world was observed, the most impactful scholarly works came from the West and Asia. Finally, it was found that research on change management could be classified into four schools of thought; engineering and information and communication technology (ICT) industry, organisational aspects of change, leadership aspects of change and human aspects of change.

Originality/value

This study contributes to the knowledge base on change management by creating an intellectual landscape of the existing research. The results demonstrated that the existing literature on the topic forms four broad clusters of knowledge and that the ICT industry is the current epicentre of research in this area. These findings could benefit researchers, as well as practitioners in streamlining their actions towards the most relevant and critical areas on the topic of change management.