bluuebunny/crossref_metadata_2025 huggingface dataset:
Arresting microbiome development limits immune system maturation and resistance to infection
Authors: Lubin Jean-Bernard , Green Jamal , Maddux Sarah , Denu Lidiya , Duranova Tereza , Lanza Matthew , Wynosky-Dolfi Meghan , Brodsky Igor E. , Planet Paul J. , Silverman Michael A.
Published: January 2022

Disruptions to the intestinal microbiome during weaning lead to long-term negative effects on host immune function. However, the critical host-microbe interactions occurring during weaning required for healthy immune system development remain poorly understood. We find that restricting microbiome maturation during weaning leads to stunted immune system development and increased susceptibility to enteric infection. We developed a gnotobiotic mouse model of the early-life microbiome designated as Pediatric Community (PedsCom). This nine-member consortium of microbes derived from intestinal microbiomes of preweaning mice stably colonized germfree adult mice and was efficiently transmitted to offspring for multiple generations. Unexpectedly, the relative abundance of PedsCom microbes were largely unaffected by the transition from a milk-based to a fiber rich solid food diet. PedsCom mice developed less peripheral regulatory T cells and Immunoglobulin A, hallmarks of microbiota-driven immune system development. Consistent with defects in maturation, adult PedsCom mice retain high susceptibility to salmonella infection characteristic of young mice and humans. Altogether, our work illustrates how the post-weaning transition in intestinal microbiome composition contributes to normal immune maturation and protection from enteric infection. Accurate modelling of the pre-weaning microbiome provides a window into the microbial requirements of healthy immune development and suggests an opportunity to design microbial interventions at weaning to improve immune system development in human infants.

One Sentence Summary

Arresting microbiome development stunts immune ontogeny
Structural basis for Nirmatrelvir in vitro efficacy against SARS-CoV-2 variants
Authors: Greasley Samantha E , Noell Stephen , Plotnikova Olga , Ferre Rose Ann , Liu Wei , Bolanos Ben , Fennell Kimberly , Nicki Jennifer , Craig Tim , Zhu Yuao , Stewart Al E , Steppan Claire M
Published: January 2022

The COVID-19 pandemic continues to be a public health threat with emerging variants of SARS-CoV-2. Nirmatrelvir (PF-07321332) is a reversible, covalent inhibitor targeting the main protease (Mpro) of SARS-CoV-2 and the active protease inhibitor in PAXLOVID™ (nirmatrelvir tablets and ritonavir tablets). We evaluated the in vitro catalytic activity and in vitro potency of nirmatrelvir against the main protease (Mpro) of prevalent variants of concern (VOC) or variants of interest (VOI): Alpha (α, B.1.1.7), Beta (β, B.1.351), Delta (δ, B1.617.2), Gamma (γ, P.1), Lambda (λ, B.1.1.1.37/C37), Omicron (o, B.1.1.529) as well as the original Washington or wildtype strain. These VOC/VOI carry prevalent mutations at varying frequencies in the Mpro specifically for: α, β, γ (K90R), λ (G15S) and o (P132H). In vitro biochemical enzymatic assay characterization of the enzyme kinetics of the mutant Mpros demonstrate that they are catalytically comparable to wildtype. Nirmatrelvir has similar potency against each mutant Mpro including P132H that is observed in the Omicron variant with a Ki of 0.635 nM as compared to a Ki of 0.933nM for wildtype. The molecular basis for these observations were provided by solution-phase structural dynamics and structural determination of nirmatrelvir bound to the o, λ and β Mpro at 1.63 - 2.09 Å resolution. These in vitro data suggest that PAXLOVID has the potential to maintain plasma concentrations of nirmatrelvir many-fold times higher than the amount required to stop the SARS-CoV-2 VOC/VOI, including Omicron, from replicating in cells (1).
Super-silencers regulated by chromatin interactions control apoptotic genes
Authors: Zhang Ying , Chen Kaijing , Cai Yichao , Nambu Akiko , See Yi Xiang , Fu Chaoyu , Raju Anandhkumar , Lakshmanan Manikandan , Osato Motomi , Tergaonkar Vinay , Fullwood Melissa Jane
Published: January 2022

Human silencers have been shown to exist and regulate developmental gene expression. However, the functional importance of human silencers needs to be elucidated such as the working mechanism and whether they can form “super-silencers”. Here, through interrogating two putative silencer components of FGF18 gene, we found that two silencers can cooperate via compensated chromatin interactions to form a “super-silencer”. Furthermore, double knock-out of two silencers exhibited synergistic upregulation of FGF18 expression and changes of cell identity. To disturb the “super-silencers”, we applied combinational treatment of an EZH2 inhibitor GSK343, and a REST inhibitor, X5050 (“GR”). We found that GR led to severe loss of TADs and loops, while the use of just one inhibitor by itself only showed mild changes. Such changes of TADs and loops may due to reduced CTCF protein level observed upon GR treatment. Moreover, GSK343 and X5050 worked together synergistically to upregulate the apoptotic genes controlled by super-silencers, and thus gave rise to antitumor effects including apoptosis, cell cycle arrest and tumor growth inhibition. Overall, our data demonstrated the first example of a “super-silencer” and showed that combinational usage of GSK343 and X5050 could potentially lead to cancer ablation through disruption of “super-silencers”.
Activation of the Integrated Stress Response overcomes multidrug resistance in FBXW7-deficient cells
Authors: Sanchez-Burgos Laura , Navarro-González Belén , García-Martín Santiago , Tejero Héctor , Antón Marta Elena , Al-Shahrour Fátima , Fernandez-Capetillo Oscar
Published: January 2022

FBXW7 is one of the most frequently mutated tumor suppressors, the deficiency of which has been associated with resistance to some anticancer therapies. Through bioinformatic analyses and genome-wide CRISPR screens, we here reveal that FBXW7 deficiency leads to multidrug resistance (MDR), to a bigger extent than well-established MDR-drivers such as overexpression of the drug-efflux pump ABCB1. Proteomic data from FBXW7-deficient cancer cells identify the upregulation of mitochondrial function as a hallmark of FBXW7 deficiency, which has been previously linked to an increased resistance to chemotherapy. Accordingly, genetic or chemical targeting of mitochondria is preferentially toxic for FBXW7-deficient cells in vitro and in vivo. Mechanistically, we show that the toxicity associated with therapies that target mitochondrial translation such as the antibiotic tigecycline relates to the activation of the Integrated Stress Response (ISR). Furthermore, while searching for additional drugs that could overcome the MDR of FBXW7-deficient cells, we found that all of them unexpectedly also activated the ISR regardless of their currently accepted mechanism of action. Together, our study reveals that one of the most frequent mutations in cancer reduces the sensitivity to the vast majority of available therapies, and identifies a general principle to overcome such resistance.
Single cell profiling of γδ hepatosplenic T-cell lymphoma unravels tumor cell heterogeneity associated with disease progression
Authors: Song Wei , Zhang Haixi , Yang Fan , Nakahira Kiichi , Wang Cheng , Shi Keqian , Zhang Ruoyu
Published: January 2022

Hepatosplenic T-cell lymphoma (HSTCL), mostly derived from γδ T cells, is a rare but very aggressive lymphoma with poor outcomes. The molecular pathogenesis driving HSTCL is largely unknown while only limited treatment options are available. In this study, by performing paired single cell RNA-seq and T cell receptor (TCR) sequencing on biopsies from a HSTCL patient pre- and post-chemotherapy treatments, we characterized unique gene expressing signatures of malignant γδ T cells, with a set of marker genes were newly identified in HSTCL (AREG, PLEKHA5, VCAM1 etc.). Although the malignant γδ T cells were expanded from a single TCR clonotype according to their TCR identities, they evolved into two transcriptional distinct tumor subtypes during the disease progression. The Tumor_1 subtype was dominant in pre-treatment samples with highly aggressive phenotypes. While the Tumor_2 had relative mild cancer hallmark signatures but expressed genes associated with tumor survival signal and drug resistance (IL32, TOX2, AIF1, AKAP12 etc.), and finally became the main tumor subtype post-treatment. We further dissected the tumor microenvironment of the HSTCL and noticed that CD8 memory T cells were clonal expanded post-treatment. In addition, we discovered dynamically rewiring cell-cell interaction networks during the treatment. The tumor cells had reduced communications with the microenvironment post-treatment. Our study reveals heterogenous and dynamic tumor and microenvironment underlying pathogenesis of HSTCL and may contribute to identify novel targets for diagnosis and cure of HSTCL in the future.
xia2.multiplex: a multi-crystal data analysis pipeline
Authors: Gildea Richard J. , Beilsten-Edmands James , Axford Danny , Horrell Sam , Aller Pierre , Sandy James , Sanchez-Weatherby Juan , Owen C. David , Lukacik Petra , Strain-Damerell Claire , Owen Robin L. , Walsh Martin A. , Winter Graeme
Published: January 2022

In macromolecular crystallography radiation damage limits the amount of data that can be collected from a single crystal. It is often necessary to merge data sets from multiple crystals, for example small-wedge data collections on micro-crystals, in situ room-temperature data collections, and collection from membrane proteins in lipidic mesophase. Whilst indexing and integration of individual data sets may be relatively straightforward with existing software, merging multiple data sets from small wedges presents new challenges. Identification of a consensus symmetry can be problematic, particularly in the presence of a potential indexing ambiguity. Furthermore, the presence of non-isomorphous or poor-quality data sets may reduce the overall quality of the final merged data set.

To facilitate and help optimise the scaling and merging of multiple data sets, we developed a new program, xia2.multiplex, which takes data sets individually integrated with DIALS and performs symmetry analysis, scaling and merging of multicrystal data sets. xia2.multiplex also performs analysis of various pathologies that typically affect multi-crystal data sets, including non-isomorphism, radiation damage and preferential orientation. After describing a number of use cases, we demonstrate the benefit of xia2.multiplex within a wider autoprocessing framework in facilitating a multi-crystal experiment collected as part of in situ room-temperature fragment screening experiments on the SARS-CoV-2 main protease.
AXL-TBK1 driven nuclear AKT3 promotes metastasis
Authors: Arner Emily N. , Westcott Jill M. , Hinz Stefan , Tiron Crina Elena , Blø Magnus , Mai Anja , Virtakoivu Reetta , Phinney Natalie , Nord Silje , Aguilera Kristina Y. , Rizvi Ali , Toombs Jason E. , Reese Tanner , Fey Vidal , Micklem David , Gausdal Gro , Ivaska Johanna , Lorens James B. , Brekken Rolf A.
Published: January 2022

Epithelial-to-mesenchymal transition (EMT) contributes to tumor cell survival, immune evasion, migration, invasion, and therapy resistance. Across human cancer, tumors that are high grade, poorly differentiated, and have undergone EMT carry a worse prognosis with a higher likelihood of metastasis. AXL, a receptor tyrosine kinase, drives EMT and is implicated in tumor progression, metastasis, and therapy resistance in multiple cancer types including pancreatic cancer and breast cancer. TANK-binding kinase 1 (TBK1) is central to AXL-driven EMT yet, the mechanism of how TBK1 induces EMT remains unclear. Here, we report that AXL activation stimulates TBK1 binding and phosphorylation of AKT3. TBK1 activation of AKT3 drives binding and phosphorylation of slug/snail resulting in protection from proteasomal degradation and translocation of the complex into the nucleus. We show that nuclear translocation of AKT3 is required for AXL-driven EMT and metastasis. Congruently, nuclear AKT3 expression correlates with worse outcome in aggressive breast cancer. To advance AKT3 as a therapeutic target, an AKT3-isoform selective allosteric small molecule inhibitor, BGB214, was developed. BGB214 inhibits AKT3 nuclear translocation, EMT-TF stability, AKT3-mediated invasion of breast cancer cells and reduces tumor initiation in vivo. Our results suggest that AKT3 nuclear activity is an important feature of AXL-driven epithelial plasticity and that selective AKT3 inhibition represents a novel therapeutic avenue for treating aggressive cancer.

Significance

Nuclear AKT3 activity is an important feature of AXL-TBK1 driven EMT and metastasis, thus selective AKT3 targeting represents a novel approach to treat aggressive cancer.
Mapping the developing human immune system across organs
Authors: Suo Chenqu , Dann Emma , Goh Issac , Jardine Laura , Kleshchevnikov Vitalii , Park Jong-Eun , Botting Rachel A. , Stephenson Emily , Engelbert Justin , Tuong Zewen Kelvin , Polanski Krzysztof , Yayon Nadav , Xu Chuan , Suchanek Ondrej , Elmentaite Rasa , Conde Cecilia Domínguez , He Peng , Pritchard Sophie , Miah Mohi , Moldovan Corina , Steemers Alexander S. , Prete Martin , Marioni John C. , Clatworthy Menna R. , Haniffa Muzlifah , Teichmann Sarah A.
Published: January 2022

Recent advances in single cell genomics technologies have facilitated studies on the developing immune system at unprecedented scale and resolution. However, these studies have focused on one or a few organs and were thus limited in understanding the developing immune system as a distributed network across tissues. Here, we profiled prenatal haematopoietic organs, lymphoid organs and non-lymphoid tissues using a combination of single-cell RNA sequencing, paired antigen-receptor sequencing and spatial transcriptomics to reconstruct the developing human immune system. Our analysis revealed the acquisition of immune effector transcriptome profiles in macrophages, mast cells and NK cells from the second trimester, and the transcriptomic changes accompanying the late-stage maturation of developing monocytes and T cells that extended from their organ of origin to peripheral tissues. We uncovered system-wide blood and immune cell development beyond the conventional primary haematopoietic organs. We further identified, extensively characterised and functionally validated the human prenatal B1 cells. Finally, we provide evidence for thymocyte-thymocyte selection origin for αβTCR- expressing unconventional T cells based on TCR gene usage and anin vitroartificial thymic organoid culture model. Our comprehensive atlas of the developing human immune system provides both valuable data resources and biological insights that will facilitate cell engineering, regenerative medicine and disease understanding.

One-Sentence Summary

By performing a comprehensive single-cell RNA sequencing atlas of human developing immune system together with antigen-receptor sequencing and spatial transcriptomics, we explored the cross-gestation and cross-organ variability in immune cells, discovered system-wide blood and immune cell development, identified, characterised and functionally validated the properties of human prenatal B1 cells and the origin of unconventional T cells.
Ultra high diversity factorizable libraries for efficient therapeutic discovery
Authors: Dai Zheng , Saksena Sachit D. , Horny Geraldine , Banholzer Christine , Ewert Stefan , Gifford David K.
Published: January 2022

The successful discovery of novel biological therapeutics by selection requires highly diverse libraries of candidate sequences that contain a high proportion of desirable candidates. Here we propose the use of computationally designed factorizable libraries made of concatenated segment libraries as a method of creating large libraries that meet an objective function at low cost. We show that factorizable libraries can be designed efficiently by representing objective functions that describe sequence optimality as an inner product of feature vectors, which we use to design an optimization method we call Stochastically Annealed Product Spaces (SAPS). We then use this approach to design diverse and efficient libraries of antibody CDR-H3 sequences with various optimized characteristics.
A genome-wide screen identifies SCAI as a modulator of the UV-induced replicative stress response in human cells
Authors: Lemay Jean-François , St-Hilaire Edlie , Gezzar-Dandashi Sari , McQuaid Mary , Ronato Daryl A. , Gao Yuandi , Bélanger François , Sawchyn Christina , Ishimwe Aimé Boris Kimenyi , Mallette Frédérick A. , Masson Jean-Yves , Drobetsky Elliot A. , Wurtele Hugo
Published: January 2022

Helix-destabilizing DNA lesions induced by environmental mutagens such as UV light cause genomic instability by strongly blocking the progression of DNA replication forks (RF). At blocked RF, single-stranded DNA (ssDNA) accumulates and is rapidly bound by Replication Protein A (RPA) complexes. Such stretches of RPA-ssDNA constitute platforms for recruitment/activation of critical factors that promote DNA synthesis restart. However, during periods of severe replicative stress, RPA availability may become limiting due to inordinate sequestration of this multifunctional complex on ssDNA, thereby negatively impacting multiple vital RPA-dependent processes. Here, we performed a genome-wide screen to identify factors which restrict the accumulation of RPA-ssDNA during UV-induced replicative stress. While this approach revealed some expected “hits” acting in pathways such as nucleotide excision repair, translesion DNA synthesis, and the intra-S phase checkpoint, it also identifed SCAI, whose role in the replicative stress response was previously unappreciated. Upon UV exposure, SCAI knock-down caused elevated accumulation of RPA-ssDNA during S phase, accompanied by reduced cell survival and compromised RF progression. These effects were independent of the previously reported role of SCAI in 53BP1-dependent DNA double-strand break repair. We also found that SCAI colocalized with stalled RF, and that its depletion promoted nascent DNA degradation. Finally, we (i) provide evidence that EXO1 is the major nuclease underlying ssDNA formation and consequent DNA replication defects in SCAI knockout cells and, consistent with this, (ii) demonstrate that SCAI inhibits EXO1 activity on a ssDNA gap in vitro. Taken together, our data establish SCAI as a novel regulator of the replicative stress response in human cells.
SARS-CoV-2 induces human endogenous retrovirus type W envelope protein expression in blood lymphocytes and in tissues of COVID-19 patients
Authors: Charvet Benjamin , Brunel Joanna , Pierquin Justine , Iampietro Mathieu , Decimo Didier , Queruel Nelly , Lucas Alexandre , del Mar Encabo-Berzosa María , Arenaz Izaskun , Marmolejo Tania Perez , Morales Francina Valezka Bolaños , Gonzalez Arturo Ivan Gonzalez , Maldonado Armando Castorena , Rivero César Luna , Mathieu Cyrille , Küry Patrick , Flores-Rivera Jose , Rios Santiago Avila , de Oca Gonzalo Salgado Montes , Schoorlemmer Jon , Horvat Branka , Perron Hervé
Published: January 2022

Patients with COVID-19 may develop abnormal inflammatory response and lymphopenia, followed in some cases by delayed-onset syndromes, often long-lasting after the initial SARS-CoV-2 infection. As viral infections may activate human endogenous retroviral elements (HERV), we studied the effect of SARS-CoV-2 on HERV-W and HERV-K envelope (ENV) expression, known to be involved in immunological and neurological pathogenesis of human diseases. Our results have showed that the exposure to SARS-CoV-2 virus activates early HERV-W and K transcription but only HERV-W ENV protein expression, in an infection- and ACE2-independent way within peripheral blood mononuclear cell cultures from one-third of healthy donors. Moreover, HERV-W ENV protein was significantly increased in serum and plasma of COVID-19 patients, correlating with its expression in CD3+ lymphocytes and with disease severity. Finally, HERV-W ENV was found expressed in post-mortem tissues of lungs, heart, brain olfactory bulb and nasal mucosa from acute COVID-19 patients in cell-types relevant for COVID-19-associated pathogenesis within affected organs, but different from those expressing of SARS-CoV-2 antigens. Altogether, the present study revealed that SARS-CoV-2 can induce HERV-W ENV expression in cells from individuals with symptomatic and severe COVID-19. Our data suggest that HERV-W ENV is likely to be involved in pathogenic features underlying symptoms of acute and post-acute COVID. It highlights the importance to further understand patients’ genetic susceptibility to HERV-W activation and the relevance of this pathogenic element as a prognostic marker and a therapeutic target in COVID-19 associated syndromes.

Graphical abstract
Genomic surveillance of Bacillus cereus sensu lato strains isolated from meat and poultry products in South Africa enables inter- and intra-national surveillance and source tracking
Authors: Carroll Laura M. , Pierneef Rian , Mathole Aletta , Atanda Abimbola , Matle Itumeleng
Published: January 2022

Members of the Bacillus cereus sensu lato (s.l.) species complex, also known as the B. cereus group, vary in their ability to cause illness, but are frequently isolated from foods, including meat products; however, food safety surveillance efforts that employ whole-genome sequencing (WGS) often neglect these potential pathogens. Here, WGS was used to characterize B. cereus s.l. strains (n = 25) isolated during surveillance of meat products in South Africa. Strains were collected from beef, poultry, and mixed meat products obtained from (i) retail outlets, processing plants, and butcheries across six South African provinces (n = 15, 7, and 1, respectively), and (ii) imports in cold stores (n = 2). Strains were assigned to panC Groups IV, III, II, and V (n = 18, 5, 1, and 1, respectively) and spanned multiple genomospecies, regardless of the taxonomy used. All strains possessed diarrheal toxin-encoding genes, while one sequence type 26 (ST26) strain possessed cereulide (emetic toxin) synthetase-encoding genes. No strains harbored anthrax toxin- or capsule-encoding genes. The 25 strains were partitioned into 15 lineages via in silico seven-gene multi-locus sequence typing (MLST), six of which contained multiple strains sequenced in this study, which were identical or nearly identical at the whole-genome scale. Five MLST lineages contained (nearly) identical genomes collected from two or three South African provinces; one MLST lineage contained nearly identical genomes from two countries (South Africa and the Netherlands), indicating that B. cereus s.l. can spread intra- and inter-nationally via foodstuffs.

Importance

Nation-wide foodborne pathogen surveillance programs that employ high-resolution genomic methods have been shown to provide vast public health and economic benefits. However, B. cereus s.l. are often overlooked during large-scale, routine WGS efforts. Thus, to our knowledge, no studies to date have evaluated the potential utility of WGS for B. cereus s.l. surveillance and source tracking in foodstuffs. In this proof-of-concept study, we applied WGS to B. cereus s.l. strains collected via South Africa’s national surveillance program of domestic and imported meat products, and we provide strong evidence that B. cereus s.l. can be disseminated intra- and inter-nationally via the agro-food supply chain. Our results showcase that WGS can be used for source tracking of B. cereus s.l. in foods, although future WGS and isolate metadata collection efforts are needed to ensure that B. cereus s.l. surveillance initiatives are on par with those of other foodborne pathogens.
Effect of habitual reading direction on saccadic eye movements
Authors: Lyu A , Abel L , Cheong AMY
Published: January 2022

Cognitive processes can influence the characteristics of saccadic eye movements. Reading habits, including habitual reading direction, also affects cognitive and visuospatial processes, favouring attention to the side where reading begins. Few studies have investigated the effect of habitual reading direction on saccade directionality of low-cognitive-demand stimuli (such as dots). The current study examined horizontal prosaccade, antisaccade and self-paced saccade in subjects with two primary habitual reading directions. We hypothesised that saccades responding to the target in subject’s habitual reading direction would show a longer prosaccade latency and lower antisaccade error rate (errors being a reflexive glance to a sudden-appearing target, rather than a saccade away from it). Sixteen young Chinese participants with primary habitual reading direction from left to right and sixteen young Arabic and Persian participants with primary habitual reading direction from right to left were recruited. Subjects needed to look towards a 5°/ 10°target in the prosaccade task or look towards the mirror image location of the target in the antisaccade task and look between two 10-degree targets in the self-paced saccade task. Only Arabic and Persian participants showed a shorter and directional prosaccade latency towards 5°target against their habitual reading direction. No significant effect of primary reading direction on antisaccade latency towards the correct directions was found. However, we found that Chinese readers generated significantly shorter prosaccade latencies and higher antisaccade directional errors compared with Arabic and Persian readers. The present study provides an insight into the effect of reading habits on saccadic eye movements in response to low-cognitive-demand stimuli and offers a platform for future studies to investigate the relationship between reading habits and neural mechanisms of eye movement behaviours.
A wide-field micro-computed tomography detector: micron resolution at half-centimetre scale
Authors: Yakovlev Maksim A. , Vanselow Daniel J. , Ngu Mee Siing , Zaino Carolyn R. , Katz Spencer R. , Ding Yifu , Parkinson Dula , Wang Steve Yuxin , Ang Khai Chung , La Riviere Patrick , Cheng Keith C.
Published: January 2022

Ideal three-dimensional imaging of complex samples made up of micron-scale structures extending over mm to cm, such as biological tissues, requires both wide field of view and high resolution. For existing optics and detectors used for micro-CT (computed tomography) imaging, sub-micron pixel resolution can only be achieved for fields of view of <2 mm. This article presents a unique detector system with a 6 mm field-of-view image circle and 0.5 µm pixel size that can be used in micro-CT units utilizing both synchrotron and commercial X-ray sources. A resolution-test pattern with linear microstructures and whole adult Daphnia magna were imaged at beamline 8.3.2 of the Berkeley Advanced Light Source. Volumes of 10000 × 10000 × 7096 isotropic 0.5 µm voxels were reconstructed over a 5.0 mm × 3.5 mm field of view. Measurements in the projection domain confirmed a 0.90 µm measured spatial resolution that is largely Nyquist-limited. This unprecedented combination of field of view and resolution dramatically reduces the need for sectional scans and computational stitching for large samples, ultimately offering the means to elucidate changes in tissue and cellular morphology in the context of larger, whole, intact model organisms and specimens. This system is also anticipated to benefit micro-CT imaging in materials science, microelectronics, agricultural science and biomedical engineering.
Effects of stress, strain rate and sulfate-reducing bacteria on corrosion behavior of X70 pipeline steel
Authors: Wang Yue , Wang Dan , Zhao Meng , Xie Fei , Zhang Kaili
Published: January 2022

Purpose

The purpose of this study is to find the multi-factor influence law of stress, strain rate and sulfate-reducing bacteria (SRB) on X70 pipeline steel in a simulated solution of sea mud and the order of influence of the three factors on X70 steel to develop a scientific basis for pipeline corrosion protection.

Design/methodology/approach

This paper studied the effects of stress, strain rate and SRB on the X70 pipeline steel corrosion behavior in simulated sea mud solution through orthogonal testing, electrochemical experiments and morphological observations.

Findings

The results of this study showed that stress proved to be the most relevant element for corrosion behavior, followed by SRB and strain rate. At high stresses (301 MPa and 576 MPa), stress dominated the corrosion behavior of X70 pipeline steel. However, at low stress (82 MPa), SRB played the most important role.

Originality/value

Subsea pipelines are in a very complex environmental regime that includes stress, strain rates and SRB, which often cause pipeline pitting and perforation. However, most scholars have only looked into the influence of single factors on metal corrosion. So, the single-factor experimental results of previous studies could hardly be applied to actual working conditions. There is an urgent need to understand the multi-factor influence law of stress, strain and SRB acting together on the pipeline corrosion behavior, especially to determine the dominant factor.
Dynamic model to characterise sectors using machine learning techniques
Authors: Pérez Moreno Francisco , Gómez Comendador Víctor Fernando , Delgado-Aguilera Jurado Raquel , Zamarreño Suárez María , Janisch Dominik , Arnaldo Valdes Rosa María
Published: January 2022

Purpose

The purpose of this paper is to set out a methodology for characterising the complexity of air traffic control (ATC) sectors based on individual operations. This machine learning methodology also learns from the data on which the model is based.

Design/methodology/approach

The methodology comprises three steps. Firstly, a statistical analysis of individual operations is carried out using elementary or initial variables, and these are combined using machine learning. Secondly, based on the initial statistical analysis and using machine learning techniques, the impact of air traffic flows on an ATC sector are determined. The last step is to calculate the complexity of the ATC sector based on the impact of its air traffic flows.

Findings

The results obtained are logical from an operational point of view and are easy to interpret. The classification of ATC sectors based on complexity is quite accurate.

Research limitations/implications

The methodology is in its preliminary phase and has been tested with very little data. Further refinement is required.

Originality/value

The methodology can be of significant value to ATC in that when applied to real cases, ATC will be able to anticipate the complexity of the airspace and optimise its resources accordingly.
Barriers to entry of gig workers in the gig platforms: exploring the dark side of the gig economy
Authors: Behl Aastha , Rajagopal K. , Sheorey Pratima , Mahendra Ashish
Published: January 2022

Purpose

The alternative arrangements to traditional employment have become a promising area in the gig economy with the technological advancements dominating every work. The purpose of this paper is to explore the barriers to the entry of gig workers in gig platforms pertaining to the food delivery sector. It proposes a framework using interpretive structural modelling (ISM) for which systematic literature review is done to extract the variables. This analysis helps to examine the relationship between the entry barriers to gig platforms. The study further proposes strategies to reduce the entry barriers in gig sector which would help to enhance productivity and generate employment opportunities.

Design/methodology/approach

The study uses interpretive structural model (ISM) to ascertain the relationship between various entry barriers of the gig workers to the gig platforms. It also validates the relationship and understand the reasons of their association along with MICMAC analysis. The model was designed by consulting the gig workers and the experts allied to food delivery gig platforms namely Zomato and Swiggy.

Findings

It was observed that high competition, longer login hours and late-night deliveries are the significant barriers with high driving power and low dependence power. Poor payment structures and strict terms and conditions for receiving the incentives are interdependent on each other and have moderate driving and dependence power. The expenses borne by the gig workers, such as Internet, fuel and vehicle maintenance expenses have high dependence power and low driving power. Hence, they are relatively less significant than other barriers.

Research limitations/implications

The study is confined to food delivery sector of India, without considering other important sectors of gig economy for generalizing the framework. As the study is based on forming an ISM framework through literature review only, it does not consider other research methods for analysing the entry barriers to the gig platforms.

Practical implications

The study attempts to dig out the low entry barriers for gig workers in food delivery platforms as there is a dearth of analysis of these factors. This study would weave them using ISM framework to help the gig platforms overcome these barriers at various levels, thus adding to the body of literature.

Originality/value

The study discusses the need for understanding relationship between the entry barriers in the form of ISM model to identify the dependent and driving factors of the same.
Public psychological crisis reports: an investigation during the remission of COVID-19 in China
Authors: Han Shuai , Sun Tongtong , Sun Yanming , Gao Xi
Published: January 2022

Purpose

The COVID-19 outbreak has been effectively controlled in China, but the resulting public psychological crisis is a latent, persistent and torturous disaster. This crisis affects not only the individual’s health but also social stability. This study aims to reveal the structure and situation of public psychological crisis during the remission period of the COVID-19 epidemic.

Design/methodology/approach

A questionnaire survey of the psychological crisis was conducted from February to May 2021. Data was collected from 1,056 respondents from different provinces in China.

Findings

The findings reveal the dangerous risks of public psychological crises. The specific results are as follows: first, a hierarchical state structure of psychological crisis is constructed and characterized as a significant gradient decline, namely, anxious state>panic state>depressive state>hostile state. Second, 43.939% of respondents reported an anxious state, 46.780% reported a panic state, 40.909% reported a depressive state, 28.883% reported a hostile state and 22.254% of the respondents had four psychological crisis states. Third, those with 56–65 years of age, equal or below high school and PhD, with monthly family incomes of ¥50,000–¥100,000 and living in the county and city areas have relatively high levels of psychological crisis.

Originality/value

This study enriches the research on the evolution of the psychological crisis in terms of structure and periods. This study also provides substantial evidence for hierarchical intervention and differentiated intervention of psychological crisis.
Attracting Generation Z talents to the hospitality industry through COVID CSR practices
Authors: Sun Jie , Leung Xi Yu , Zhang Huiying , Williams Kim
Published: January 2022

Purpose

This study aims to examine how COVID-related corporate social responsibility (CSR) activities affect future Generation Z employees’ intention to join the hotel industry through experimental designs.

Design/methodology/approach

Based on signaling theory, construal level theory and value theory, this study established an integrated research framework to explain the mechanism of CSR communication. The proposed study conducted three online experiments on a total of 463 participants. ANCOVA test and PROCESS macro were performed to analyze the data for main, mediation and moderation effects.

Findings

The results of this study indicate that in-kind donation is more efficacious in improving Generation Z’s job pursuit intention, as compared to cause-related marketing (CRM). CSR messages framed in a “how” mindset are favored by Generation Z members who are either unemployed or eager to change their current job. The findings also confirm the effect of brand warmth as a mediator and other-regarding personal value as a moderator.

Research limitations/implications

The present study contributes to the limited knowledge on CSR initiatives by addressing the research gap of future employees and examining CSR as a response to COVID-19. The findings also provide hotel executives actionable implications to plan and communicate future CSR programs, especially during times of crisis.

Originality/value

This study is one of the first studies to address Generation Z employees and to investigate the role of CSR initiatives on future hotel workers.
Lubrication properties of silver complexes under the high temperature abrupt operating conditions
Authors: Zhang Xiuheng , Hu Ningning , Chen Tianchi , Wang Songquan
Published: January 2022

Purpose

This study aims to prevent the sharp decline in the load-carrying capacity of lubricating oil film under harsh conditions of abrupt changes in friction interface temperature, which is a major challenge in lubrication technology.

Design/methodology/approach

In this paper, we synthesized a series of silver pyrazole methylpyridine complexes containing a high metal concentration and minimal supporting organic ligands (complex 1 [Ag(LMe)]2(BF4)2, complex 2 [Ag(Li-Pr)n](BF4)n and complex 3 [Ag(LMe)(NO3)]2). The thermal decompose behavior of as-prepared silver complex was investigated by thermogravimetric analysis and X-ray photoelectron spectrometry (XPS). Four-ball friction testers were used to evaluate the friction and wear properties of lubricating oil in the temperature ranges associated with the operation of modern heavy machinery.

Findings

The complex decomposed silver particles at high-temperature, which could fill the pits on the friction surface, change the wear form of the friction pair and reduce the roughness of the friction surface. Reduction in both friction coefficients and wear scar diameters was obtained by adding silver complexes in oil. The lubricating oil, with the additive content of 1.5 Wt.%, has the best tribological performance, moreover, the lubricating performance of the silver complexes in oil were correlated with their concentration and thermal decomposed temperatures, respectively.

Originality/value

As a result, a series of silver pyrazole methylpyridine complexes as oil additives can support friction and wear reduction under abrupt high-temperature conditions are intended to be a controllable backup lubricant additive.
Monetary policy effectiveness in Africa: the role of financial development and institutional quality
Authors: Fiador Vera , Sarpong-Kumankoma Emmanuel , Karikari Nana Kwasi
Published: January 2022

Purpose

This study aims to provide empirical evidence of the pass-through effect of monetary policy on bank lending rates vis-à-vis the potential moderating effects of financial sector development and institutional quality in Africa.

Design/methodology/approach

The study uses robust fixed effects panel data estimation techniques and data from 1990 to 2017 across 37 countries in Africa.

Findings

The results show that financial development aids in the effectiveness of monetary policy transmission. A decomposition of financial development into financial institution development and financial market development shows that financial institutional development is more influential with regard to effectiveness of the interest rate pass-through compared to financial market development. This study again shows that improvements in the quality of institutions reduced lending rates in African economies.

Practical implications

The findings present relevant policy implications regarding effective transmission of monetary policy, by linking the pursuit of institutional quality, characterized by the control of corruption, political stability, regulatory quality, rule of law and the voice of accountability and development of financial institutions with lending rates and ultimately the demand for growth capital.

Originality/value

This study contributes to the literature on the factors influencing the effectiveness of monetary policy. This study considers financial sector development and institutional quality as conduits to monetary policy effectiveness in developing African countries.
Retail tenant mix effect on shopping mall’s performance
Authors: Xu Yishuang , Yiu Chung Yim , Cheung Ka Shing
Published: January 2022

Purpose

Achieving a balanced tenant mix is a long-standing discourse in the retailing and consumer marketing literature. From the perspective of marketing mix planning, the diversity of tenants is beneficial to the performance of shopping malls. This paper aims to use a revealed preference approach to study empirically the effect of retail tenant mix planning on the rents of shopping malls.

Design/methodology/approach

This study adopts a cross-disciplinary approach to develop the Island-Species-Area-Energy model to study the shopping mall marketing and management framework. The empirical data are obtained from the 129 major shopping malls in the UK.

Findings

The results confirm that the retail tenant mix is positively associated with mall size and shopping district purchasing power, implying a tenant mix equilibrium. Any deviations from the tenant mix equilibrium will impose a negative impact on total retail rents. Further, five factors, i.e. tenant mix equilibrium, building quality, locational convenience, leasing strategy and anchorage, are found to be contributing factors to retail rents.

Originality/value

The findings contribute to the current body of marketing knowledge from two perspectives: first, tenant mix effects on retail rents are empirically analysed based on the biogeography theory, which shows a tenant mix equilibrium for retail marketing planning. Second, a five-factor model on shopping mall marketing and management mix framework is developed and tested for the performance of shopping malls.
Mobility challenges and experiences for students with disabilities in Tanzania universities: dealing with a social inclusion nightmare in property management
Authors: Mubiru Moses Batanda
Published: January 2022

Purpose

Despite the presence of people with disabilities in higher learning institutions, facilities provided for both accommodation and classrooms prove to be ineffective in fulfilling their expectations. However, the existing measures have tended to be rigid and unable to incorporate the ever evolving user experiences from constantly enrolling students in public campus buildings. The paper is premised on the notion of social inclusivity of the built environment in public universities through user experiences, measured through a qualitative lens.

Design/methodology/approach

The study was qualitative and deployed a case study strategy. Respondents were purposively identified and subjected to in-depth interviews, key informant interviews and focused group discussions. The full realisation of the sample frames was determined by data saturation. Data from responses was thereafter sorted, coded and categorised through a systematic thematic analysis. Some responses reactions were reported verbatim. The anonymity of the respondents was observed though through the use of pseudonyms.

Findings

This paper has indicated respondents' experiences regarding social inclusivity of the institutional built environment and thematically categorised them in six areas: complaints mechanism and feedback, pre- and post-enrolment experiences, namely; complaints mechanism and feedback, pre- and post-enrolment experiences and social support as a property management policy. Others include, representation in university decision-making organs, perceptions regarding disability and its needs and distribution of facilities and site works. It recommends that property management practices should be re-oriented to ensure the sustainability of learning facilities for the disabled, taking into consideration the ever-evolving needs and preferences of PWD user students with disabilities.

Originality/value

Linking the social and human rights models to actual experiences of property occupiers is unique. The author believes that it will, in addition to the existing models and strategies, improve on a better achievement of inclusivity of building use used by all categories of members of the society.
Does competition in product markets affect the value of analyst coverage? Evidence from an emerging market
Authors: Farooq Omar , Bendriouch Fatimazahra , Satt Harit , Archane Saad
Published: January 2022

Purpose

This paper aims to document the impact of product market competition on the value of analyst coverage.

Design/methodology/approach

This paper uses variety of estimation techniques (panel regression as well as the quantile regression approaches) and the data for nonfinancial firms from India to document the impact of product market competition on the value of analyst coverage during the period between 2001 and 2018.

Findings

The findings show that the value of analyst coverage is an increasing function of product market competition. The authors argue that better information environment associated with firms operating in industries with high competition improves the quality of research done by analysts, thereby increasing the value of analyst coverage. The study results are consistent across different subsample and remain quantitatively the same when the authors use alternate estimation procedures.

Originality/value

The paper provides evidence regarding the role played by product market competition – a publicly available measure – on the value of research produced by analysts within the context of emerging markets.