bluuebunny/crossref_metadata_2025 huggingface dataset:
Canonical Wnt and TGF-β/BMP signaling enhance melanocyte regeneration and suppress invasiveness, migration, and proliferation of melanoma cells
Authors: Katkat Esra , Demirci Yeliz , Heger Guillaume , Karagulle Doga , Papatheodorou Irene , Brazma Alvis , Ozhan Gunes
Published: March 2022

Tissue regeneration and cancer share remarkable features including activation of cell proliferation and migration. Yet, tumors considerably differ from the regenerating tissue with respect to abnormal proliferation, invasive growth, and metastasis. Thus, it is likely that cancer resembles early stages of regeneration with increased proliferation, but separates from the later stages with reduced proliferation and enhanced differentiation. Here, by exploiting the zebrafish melanocytes that can efficiently regenerate and be induced to undergo malignant melanoma, we unravel the transcriptome profiles of the regenerating melanocytes during early and late regeneration, and the melanocytic nevi and malignant melanoma. Our global comparison of the gene expression profiles of melanocyte regeneration and nevi/melanoma uncovers the differential regulation of a substantial number of genes related to Wnt signaling and TGF-β/BMP signaling pathways between regeneration and cancer. Functional activation of canonical Wnt or TGF-β/BMP pathways during melanocyte regeneration promoted melanocyte regeneration and potently suppressed the invasiveness, migration, and proliferation of human melanoma cellsin vitroandin vivo. Therefore, differential regulation of signaling mechanisms between regeneration and cancer can be exploited to stop tumor growth and develop new anticancer therapies.
Short-chain fatty acid concentrations in the incidence and risk-stratification of colorectal cancer: a systematic review and meta-analysis
Authors: Alvandi Ehsan , Wong Wilson K M , Joglekar Mugdha V , Spring Kevin J , Hardikar Anandwardhan A
Published: March 2022

The beneficial role of gut microbiota and bacterial metabolites, including short-chain fatty acids (SCFAs), is well recognized; although the available literature around their role in colorectal cancer (CRC) has been inconsistent.

We performed a systematic review and meta-analysis to examine associations of fecal SCFA concentrations to the incidence and risk of CRC.

Data extraction through Medline, Embase, and Web of Science was carried out from database conception to May 21, 2021. Predefined criteria included human clinical observational studies, while excluding cell/animal model studies, conference proceedings, and reviews. Quality assessment of selected 16 case-control and six cross-sectional studies is reported using PRISMA 2020 guidelines. Studies were categorized for CRC risk or incidence, and RevMan 5.4 was used to perform the meta-analyses. Standardized mean differences (SMD) with 95% confidence intervals (CI) were calculated using a random-effects model.

Combined analysis of acetic-, propionic-, and butyric-acid revealed significantly lower concentrations of these SCFAs in individuals with high-risk of CRC (SMD = 2.02, 95% CI 0.31 to 3.74, P = 0.02). Further, CRC incidence increased in individuals with lower levels of SCFAs (SMD = 0.45, 95% CI 0.19 to 0.72, P = 0.0009), compared to healthy individuals.

Overall, lower fecal concentrations of the three major SCFAs is associated with higher risk and incidence of CRC.
The triadic structure of personality space in the house mouse resembles that of species with known personality badges; suggesting reciprocal hierarchies are an evolutionary motif with mixed strategies being more common
Authors: Forkosh Oren , Sinervo Barry
Published: March 2022

Differences in animal personalities are generally hard to measure - even in an animal as common as the house mouse. Yet, in some rare cases, nature has provided us with clear visual cues as to the nature of a specific individual. These so-called badges are the case for the side botched lizard, often referred to as the ‘rock-paper-scissor’ lizard. Here, we show that mice have behavioral archetypes that are similar to the triadic social dynamics of the lizards. We find analogs in territoriality, aggressiveness, and pro-social behavior linking ultra-dominant, dominant, and subordinate mice to the lizard’s orange, blue, and yellow morphs accordingly. Yet, unlike the lizards, most mice in the study displayed mixed strategies rather than fall into clear behavioral archetypes. In such a case, it makes less sense to have distinct visual cues to distinguish between personalities. The result implies that, although visual distinctions are infrequent in nature, having multiple behavioral archetypes might serve as an evolutionary motif. In addition, we find that mammals, like mice, might have circular hierarchies, similar to the lizards, where no single behavioral strategy outweighs others.
Combination treatment can hinder the evolution of resistance to antimicrobial peptides
Authors: Maron Bar , Friedman Jonathan , Hayouka Zvi
Published: March 2022

Antibiotic resistant microbial pathogens are becoming a major threat to human health. Therefore, there is an urgent need to develop new alternatives to conventional antibiotics. One such promising alternative is antimicrobial peptides (AMPs), which are produced by virtually all organisms and typically inhibit bacteria via membrane disruption. However, previous studies demonstrated that bacteria can rapidly develop AMP resistance. Here, we study whether combination therapy, known to be able to inhibit the evolution of resistance to conventional antibiotics, can also hinder the evolution of AMP resistance. To do so, we evolved the opportunistic pathogen S. aureus in the presence of individual AMP, AMP pairs, and a combinatorial antimicrobial peptide library. Treatment with some AMP pair indeed hindered the evolution of resistance compared with individual AMPs. In particular, resistance to pairs was delayed when resistance to the individual AMPs came at a cost of impaired bacterial growth, and did not confer cross-resistance to other tested AMPs. The lowest level of resistance evolved during treatment with the combinatorial antimicrobial peptide library termed random antimicrobial peptide mixture, which contains more than a million different peptides. A better understanding of how AMP combinations affect the evolution of resistance is a crucial step in order to design ‘resistant proof’ AMPs cocktails that will offer a sustainable treatment option for antibiotic resistant pathogens.
In vitro engineering of the lung alveolus
Authors: Leiby Katherine L. , Yuan Yifan , Ng Ronald , Raredon Micha Sam Brickman , Adams Taylor S. , Baevova Pavlina , Hirschi Karen K. , Campbell Stuart G. , Kaminski Naftali , Herzog Erica L. , Niklason Laura E.
Published: March 2022

Therapeutic lung regeneration is predicated upon successful reconstitution of lung alveoli, the functional units of gas exchange. Here, we identify requisite multimodal cues that are critical to reconstructing the alveolar epithelium and alveoli in lung scaffolds. Alveolar reconstruction in vitro is divided into several distinct phases. In the first phase, endothelial cells coordinate with fibroblasts and select exogenous factors to promote alveolar scaffold population with surfactant-secreting alveolar epithelial type 2 cells (AEC2s). After formation of organized epithelial alveolar-like structures, subsequent withdrawal of Wnt and FGF agonism synergizes with tidal-level mechanical strain to induce differentiation of AEC2s to squamous type 1 AECs (AEC1s) in cultured alveoli, in situ. These results outline a rational strategy to engineer an alveolus of AEC2s and AEC1s contained within epithelial-mesenchymal-endothelial units, and reveal the critical interplay amongst biochemical, cellular, and mechanical niche cues within the reconstituting alveolus.
Acidity of expiratory aerosols controls the infectivity of airborne influenza virus and SARS-CoV-2
Authors: Luo Beiping , Schaub Aline , Glas Irina , Klein Liviana K. , David Shannon C. , Bluvshtein Nir , Violaki Kalliopi , Motos Ghislain , Pohl Marie , Hugentobler Walter , Nenes Athanasios , Krieger Ulrich K. , Stertz Silke , Peter Thomas , Kohn Tamar
Published: March 2022

Enveloped viruses are prone to inactivation when exposed to strong acidity levels characteristic of atmospheric aerosol. Yet, the acidity of expiratory aerosol particles and its effect on airborne virus persistence has not been examined. Here, we combine pH-dependent inactivation rates of influenza A virus and SARS-CoV-2 with microphysical properties of respiratory fluids under indoor conditions using a biophysical aerosol model. We find that particles exhaled into indoor air become mildly acidic (pH ≈ 4), rapidly inactivating influenza A virus within minutes, whereas SARS-CoV-2 requires days. If indoor air is enriched with non-hazardous levels of nitric acid, aerosol pH drops by up to 2 units, decreasing 99%-inactivation times for both viruses in small aerosol particles to below 30 seconds.Conversely, unintentional removal of volatile acids from indoor air by filtration may elevate pH and prolong airborne virus persistence. The overlooked role of aerosol pH has profound implications for virus transmission and mitigation strategies.

One Sentence Summary

Respiratory viruses are sensitive to aerosol pH, an unidentified factor in the mitigation of airborne virus transmission
Migrants’ primary care utilisation before and during the COVID-19 pandemic in England: An interrupted time series
Authors: Zhang Claire X. , Boukari Yamina , Pathak Neha , Mathur Rohini , Katikireddi Srinivasa Vittal , Patel Parth , Campos-Matos Ines , Lewer Dan , Nguyen Vincent , Hugenholtz Greg , Burns Rachel , Mulick Amy , Henderson Alasdair , Aldridge Robert W.
Published: March 2022

Background

How international migrants access and use primary care in England is poorly understood. We aimed to compare primary care consultation rates between international migrants and non-migrants in England before and during the COVID-19 pandemic (2015– 2020).

Methods

Using linked data from the Clinical Practice Research Datalink (CPRD) GOLD and the Office for National Statistics, we identified migrants using country-of-birth, visa-status or other codes indicating international migration. We ran a controlled interrupted time series (ITS) using negative binomial regression to compare rates before and during the pandemic.

Findings

In 262,644 individuals, pre-pandemic consultation rates per person-year were 4.35 (4.34-4.36) for migrants and 4.6 (4.59-4.6) for non-migrants (RR:0.94 [0.92-0.96]). Between 29 March and 26 December 2020, rates reduced to 3.54 (3.52-3.57) for migrants and 4.2 (4.17-4.23) for non-migrants (RR:0.84 [0.8–0.88]). Overall, this represents an 11% widening of the pre-pandemic difference in consultation rates between migrants and non-migrants during the first year of the pandemic (RR:0.89, 95%CI:0.84–0.94). This widening was greater for children, individuals whose first language was not English, and individuals of White British, White non-British and Black/African/Caribbean/Black British ethnicities.

Interpretation

Migrants were less likely to use primary care before the pandemic and the first year of the pandemic exacerbated this difference. As GP practices retain remote and hybrid models of service delivery, they must improve services and ensure they are accessible and responsive to migrants’ healthcare needs.

Funding

This study was funded by the Medical Research Council (MR/V028375/1) and Wellcome Clinical Research Career Development Fellowship (206602).
Modifiable lifestyle activities affect cognition in cognitively healthy middle-aged individuals at risk for late-life Alzheimer’s Disease
Authors: Heneghan Amy , Deng Feng , Wells Katie , Ritchie Karen , Muniz-Terrera Graciela , Ritchie Craig W , Lawlor Brian , Naci Lorina
Published: March 2022

It is now acknowledged that Alzheimer’s Disease (AD) processes are present decades before the onset of clinical symptoms, but it remains unknown whether lifestyle factors can protect against these early AD processes in mid-life. We asked whether modifiable lifestyle activities impact cognition in middle-aged individuals who are cognitively healthy, but at risk for late life AD. Participants (40–59 years) completed cognitive and clinical assessments at baseline (N = 206) and two years follow-up (N = 174). Mid-life activities were measured with the Lifetime of Experiences Questionnaire. We assessed the impact of lifestyle activities, known risk factors for sporadic late-onset AD (Apolipoprotein E □4 allele status, family history of dementia, and the Cardiovascular Risk Factors Aging and Dementia score), and their interactions on cognition. More frequent engagement in physically, socially and intellectually stimulating activities was associated with better cognition (verbal, spatial and relational memory), at baseline and follow-up. Critically, more frequent engagement in these activities was associated with stronger cognition (verbal and visuospatial functions, and conjunctive short-term memory binding) in individuals with family history of dementia. Impaired visuospatial function is one of the earliest cognitive deficits in AD and has previously associated with increased AD risk in this cohort. Additionally, conjunctive memory functions have been found impaired in the pre-symptomatic stages of AD. These findings suggest that modifiable lifestyle activities offset cognitive decrements due to AD risk in mid-life and support the targeting of modifiable lifestyle activities for the prevention of Alzheimer’s Disease.
Parsing the role of NSP1 in SARS-CoV-2 infection
Authors: Fisher Tal , Gluck Avi , Narayanan Krishna , Kuroda Makoto , Nachshon Aharon , Hsu Jason C. , Halfmann Peter J. , Yahalom-Ronen Yfat , Finkel Yaara , Schwartz Michal , Weiss Shay , Tseng Chien-Te K. , Israely Tomer , Paran Nir , Kawaoka Yoshihiro , Makino Shinji , Stern-Ginossar Noam
Published: March 2022

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the cause of the ongoing coronavirus disease 19 (COVID-19) pandemic. Despite its urgency, we still do not fully understand the molecular basis of SARS-CoV-2 pathogenesis and its ability to antagonize innate immune responses. SARS-CoV-2 leads to shutoff of cellular protein synthesis and over-expression of nsp1, a central shutoff factor in coronaviruses, inhibits cellular gene translation. However, the diverse molecular mechanisms nsp1 employs as well as its functional importance in infection are still unresolved. By overexpressing various nsp1 mutants and generating a SARS-CoV-2 mutant in which nsp1 does not bind ribosomes, we untangle the effects of nsp1. We uncover that nsp1, through inhibition of translation and induction of mRNA degradation, is the main driver of host shutoff during SARS-CoV-2 infection. Furthermore, we find the propagation of nsp1 mutant virus is inhibited specifically in cells with intact interferon (IFN) response as well as in-vivo, in infected hamsters, and this attenuation is associated with stronger induction of type I IFN response. This illustrates that nsp1 shutoff activity has an essential role mainly in counteracting the IFN response. Overall, our results reveal the multifaceted approach nsp1 uses to shut off cellular protein synthesis and uncover the central role it plays in SARS-CoV-2 pathogenesis, explicitly through blockage of the IFN response.
Contribution of the Golgi apparatus in morphogenesis of a virus induced cytopathic vacuolar system
Authors: Sengupta Ranjan , Mihelc Elaine M. , Angel Stephanie , Lanman Jason K. , Kuhn Richard J. , Stahelin Robert V.
Published: March 2022

The Golgi apparatus (GA) in mammalian cells is pericentrosomally anchored and exhibits a stacked architecture. During infections by members of the alphavirus genus, the host cell GA is thought to give rise to distinct mobile pleomorphic vacuoles known as CPV-II (cytopathic vesicle-II) via unknown morphological steps. To dissect this, we adopted a phased electron tomography approach to image multiple overlapping volumes of a cell infected with Venezuelan equine encephalitis virus (VEEV) and complemented it with localization of peroxidase tagged Golgi marker. Analysis of the tomograms revealed a pattern of progressive cisternal bending into double-lamellar vesicles as a central process underpinning the biogenesis and the morphological complexity of this vacuolar system. Here we propose a model for the conversion of GA to CPV-II that reveals a unique pathway of intracellular virus envelopment. Our result has implications for alphavirus virus induced displacement of Golgi cisternae to the plasma membrane to aid viral egress operating late in the infection cycle.
Group II Intron-Like Reverse Transcriptases Function in Double-Strand Break Repair by Microhomology-Mediated End Joining
Authors: Park Seung Kuk , Mohr Georg , Yao Jun , Russell Rick , Lambowitz Alan M.
Published: March 2022

Bacteria encode free-standing reverse transcriptases (RTs) of unknown function that are closely related to group II intron-encoded RTs. Here, we found that a Pseudomonas aeruginosa group II intron-like RT (G2L4 RT) with YIDD instead of YADD at its active site functions in DNA repair in its native host and when transferred into Escherichia coli. G2L4 RT has biochemical activities strikingly similar to those of human DNA repair polymerase θ and uses them for translesion DNA synthesis and double-strand break repair (DSBR) via microhomology-mediated end-joining (MMEJ) in vitro and in vivo. We also found that a group II intron RT can function similarly to G2L4 RT in DNA repair, with reciprocal substitutions at the active site showing an I residue favors MMEJ and an A residue favors primer extension in both enzymes. The DNA repair functions of these enzymes utilize conserved structural features of non-LTR-retroelement RTs, including human LINE-1 and other eukaryotic non-LTR-retrotransposon RTs, suggesting such enzymes may have an inherent ability to function in DSBR in a wide range of organisms.
Validation of a small molecule inhibitor of PDE6D-RAS interaction with potent anti-leukemic effects
Authors: Nunes Sara Canovas , De Vita Serena , Anighoro Andrew , Autelitano François , Beaumont Edward , Klingbeil Pamela , McGuinness Meaghan , Duvert Beatrice , Harris Chad , Yang Lu , Pokharel Sheela Pangeni , Chen Chun-Wei , Ermann Monika , Williams David A. , Xu Haiming
Published: March 2022

RAS mutations prevalent in high-risk leukemia have been linked to relapse and chemotherapy resistance. Efforts to directly target RAS proteins have been largely unsuccessful. However, since RAS-mediated transformation is dependent on signaling through the RAS-related C3 botulinum toxin substrate (RAC) small GTPase, we hypothesized that targeting RAC may be an effective therapeutic approach in RAS mutated tumors. Here we describe multiple small molecules capable of inhibiting RAC activation in acute lymphoblastic leukemia cell lines. One of these, DW0254, also demonstrates promising anti-leukemic activity in RAS-mutated cells. Using chemical proteomics and biophysical methods, we identified the hydrophobic pocket of phosphodiester 6 subunit delta (PDE6D), a known RAS chaperone, as a target for this compound. Inhibition of RAS localization to the plasma membrane upon DW0254 treatment is associated with RAC inhibition through a phosphatidylinositol-3-kinase/AKT-dependent mechanism. Our findings provide new insights on the importance of PDE6D-mediated transport for RAS-dependent RAC activation and leukemic cell survival.
Imaging tools generated by CRISPR/Cas9 tagging reveal cytokinetic diversity in mammalian cells
Authors: Husser Mathieu C. , Ozugergin Imge , Resta Tiziana , Martin Vincent J. J. , Piekny Alisa J.
Published: March 2022

Cytokinesis is required to physically separate the daughter cells at the end of mitosis. This process occurs via the ingression of an actomyosin ring that assembles in anaphase and pulls in the overlying plasma membrane as it constricts. Mechanistic studies have uncovered different pathways that regulate the assembly and position of the ring in mammalian cells, but the majority of these studies were done using HeLa cells with overexpressed transgenes, and the relative requirement for these mechanisms among the majority of cell types is not known. Here, we used CRISPR/Cas9 gene editing to endogenously tag cytokinesis proteins, anillin, Ect2 and RhoA, as well as other cellular components, with fluorescent proteins. These tools enabled the visualization of cytokinesis by live imaging to quantitatively study these proteins at endogenous levels. As a proof-of-concept, tagging anillin in multiple mammalian cell lines revealed cytokinetic diversity, which will be useful for studies of how mechanisms controlling cytokinesis vary among cell types. We also successfully tagged multiple cellular components in the same cell line, demonstrating the versatility of these tagging tools.
Arctic phytoplankton spring bloom diversity across the marginal ice zone in Baffin Bay
Authors: Ribeiro Catherine Gérikas , dos Santos Adriana Lopes , Trefault Nicole , Marie Dominique , Lovejoy Connie , Vaulot Daniel
Published: March 2022

Phytoplankton under-ice blooms have been recently recognized as an important Arctic phenomenon for global primary production and biogeochemical cycling. Drastic sea-ice decline in both extension and thickness enables the development of early blooms, sometimes hundreds of kilometers beneath the pack ice. Baffin Bay is a semi-enclosed sea where Arctic and North Atlantic water masses interact. It is totally covered by sea-ice by March and ice-free by August/September. In the present work, we investigated the phytoplankton community structure across the marginal ice zone between the ice-free, Atlantic-influenced, east and the ice-covered, Arctic-influenced, west Baffin Bay using 18S rRNA high-throughput amplicon sequencing, flow cytometry cell counting and numerous environmental and biological data collected and compiled in the scope of the Green Edge project. Sampling was performed during June-July 2016 in a total of 16 stations with around 6 depths each. Stations were clustered into “Under Ice” (UI), “Marginal Ice Zone” (MIZ) and “Open Water” (OW) on the basis of its sea ice cover upon sampling. Phytoplankton community structure was analyzed by 18S rRNA metabarcoding with the microdiversity approach. The UI sector was characterized by a shallow nitracline, high pico-phytoplankton abundance and a shared dominance between Micromonas and Phaeocystis in the 0.2-3 µm size fraction, as well as an increased contribution of Cryptophyceae and non-diatom Ochrophyta in the 3-20 µm size fraction. Several amplicon sequence variants (ASVs) were flagged as indicator for the UI+MIZ sector group, including known ice-associated taxa such as the diatoms Melosira arctica and Pseudo-nitzschia seriata, but also specific ASVs assigned to the green alga Micromonas polaris and the cryptophyte Falcomonas daucoides, the silicoflagellate Dictyocha speculum, one member of the uncultivated MOCH-2 group, and a Pterosperma sp. (green algae) rarely seen in other metabarcoding datasets, including from the Arctic. The OW sector harbored a community adapted to a nutrient-depleted/high light environment, with a significant contribution of the haptophytePhaeocystis pouchetii and big centric diatoms, including several Thalassiosira species.
Laboratory changes associated with medication non-adherence in patients with hypertension over six months of the COVID-19 pandemic
Authors: Chang Shu-Mei , Chen Yi-Chun , Hsuan Chin-Feng , Lu I-Cheng , Chuang Hung-Yi
Published: March 2022

The coexistence of multiple diseases is common in the elderly and often accompanied by medication non-adherence. This study investigated the relationship between medication non- adherence and laboratory findings inpatients with hypertension and hypertensive comorbidities (i.e., diabetes and nephropathy) in southern Taiwan during 6 months of the coronavirus disease pandemic. This was a panel study and involved outpatients from three hospitals classified as regional hospitals or above. Questionnaireswere usedto collect information on patient demographics, diet, medication adherence, and laboratory data at the time of recruitment and 6 months after. A total of 140 patients with only hypertension and 98 patients with hypertension and comorbidities were recruited, and the changes inblood pressure andlaboratory data were assessed after 6 months. Analyses performed with generalized estimating equations showed that patients who had not forgotten to take medication had a higher estimated glomerular filtration rate. Moreover, patients who did not change their medication time arbitrarily had lower low- density lipoprotein levels. Furthermore, patients who did not stop or interrupt their medication arbitrarily had lower diastolic blood pressuresand low-density lipoprotein levels. Overall, patients with better medication adherence had better estimated glomerular filtration rates,lower low-density lipoprotein levels, and lower diastolic blood pressures.
Hypoxia inducible factors regulate infectious SARS-CoV-2, epithelial damage and respiratory symptoms in a hamster COVID-19 model
Authors: Wing Peter A.C. , Prange-Barczynska Maria , Cross Amy , Crotta Stefania , Orbegozo Rubio Claudia , Cheng Xiaotong , Harris James M. , Zhuang Xiaodong , Johnson Rachel L. , Ryan Kathryn A. , Hall Yper , Carroll Miles W. , Issa Fadi , Balfe Peter , Wack Andreas , Bishop Tammie , Salguero Francisco J. , McKeating Jane A.
Published: March 2022

Understanding the host pathways that define susceptibility to SARS-CoV-2 infection and disease are essential for the design of new therapies. Oxygen levels in the microenvironment define the transcriptional landscape, however the influence of hypoxia on virus replication and disease in animal models is not well understood. In this study, we identify a role for the hypoxic inducible factor (HIF) signalling axis to inhibit SARS-CoV-2 infection, epithelial damage and respiratory symptoms in Syrian hamsters. Pharmacological activation of HIF with the prolyl-hydroxylase inhibitor FG-4592 significantly reduced the levels of infectious virus in the upper and lower respiratory tract. Nasal and lung epithelia showed a reduction in SARS-CoV-2 RNA and nucleocapsid expression in treated animals. Transcriptomic and pathological analysis showed reduced epithelial damage and increased expression of ciliated cells. Our study provides new insights on the intrinsic antiviral properties of the HIF signalling pathway in SARS-CoV-2 replication that may be applicable to other respiratory pathogens and identifies new therapeutic opportunities.
Crystal structure of tetrakis(μ-4-benzyl-4H-1,2,4-triazole-κ2
N
1:N
2)tetrafluoridodi-μ2-oxido-dioxidodisilver(I)divanadium(V)
Authors: Senchyk Ganna A. , Lysenko Andrey B. , Rusanov Eduard B. , Domasevitch Kostiantyn V.
Published: March 2022

The crystal structure of the title compound, [Ag2(VO2F2)2(C9H9N3)4], is presented. The molecular complex is based on the heterobimetallic AgI—VV fragment {AgI
2(VVO2F2)2(tr)4} supported by four 1,2,4-triazole ligands [4-benzyl-(4H-1,2,4-triazol-4-yl)]. The triazole functional group demonstrates homo- and heterometallic connectivity (Ag—Ag and Ag—V) of the metal centers through the [–NN–] double and single bridges, respectively. The vanadium atom possesses a distorted trigonal–bipyramidal coordination environment [VO2F2N] with the Reedijk structural parameter τ = 0.59. In the crystal, C—H...O and C—H...F hydrogen bonds as well as C—H...π contacts are observed involving the organic ligands and the vanadium oxofluoride anions. A Hirshfeld surface analysis of the hydrogen-bonding interactions is also described.
Effect of Hg2+ on the corrosion behavior of Al-2%Zn coatings on AA5083 in 3.5 Wt.% NaCl solution
Authors: Xia Yanming , Zhou Dejing , Gao Zhiming , Hu Wenbin
Published: March 2022

Purpose

This paper aims to study the effect of Hg2+ on the corrosion behavior of Al–2%Zn coatings on AA5083 in 3.5 Wt.% NaCl solution.

Design/methodology/approach

Potentiodynamic polarization and electrochemical impedance spectroscopy are used to investigate the effect of Hg2+ on the corrosion behavior. The surface and cross-sectional morphology are characterized by scanning electron microscopy and energy dispersive spectroscopy (EDS) to further reveal the corrosion mechanism of Hg2+.

Findings

The results show that the corrosion behavior of the coating changes significantly as the concentration of Hg2+ increases from 5 to 30 μg/L. The corrosion production film can inhibit the corrosion process when Hg2+ concentration is in the range of 0.5–5 μg/L, while Hg2+ can promote the corrosion process significantly when its concentration reaches to 30 μg/L. The generation rate of dense oxide film on the coating surface is faster than dissolution rate when the concentration of Hg2+ is in the range of 0–5 μg/L, which makes the coating “self-healing” and thus slightly slows down the corrosion rate. The EDS analysis shows that excessive Hg2+ are preferentially deposited at locations with inhomogeneous electrochemical properties, which in turn accelerates corrosion.

Originality/value

The corrosion resistance of Al-based coatings is significantly affected by Hg2+ in seawater. Thus, it is important to explain the corrosion mechanism of Al–2%Zn coatings under the combined effect of Hg2+ and Cl− in 3.5 Wt.% NaCl solution.
The pre-process DV-UKF algorithm for high-precision attitude measurement with low-cost inertial sensor
Authors: Wang Rong , Wu Jin , Li Chong , Qi Shengbo , Meng Xiangrui , Wang Xinning , Zhang Chengxi
Published: March 2022

Purpose

The purpose of this paper is to propose a high-precision attitude solution to solve the attitude drift problem caused by the dispersion of low-cost micro-electro-mechanical system devices in strap-down inertial navigation attitude solution of micro-quadrotor.

Design/methodology/approach

In this study, a three-stage attitude estimation scheme that combines data preprocessing, gyro drifts prediction and enhanced unscented Kalman filtering (UKF) is proposed. By introducing a preprocessing model, the quaternion orientation is calculated as the composition of two algebraic quaternions, and the decoupling feature of the two quaternions makes the roll and pitch components independent of magnetic interference. A novel real-time based on differential value (DV) estimation algorithm is proposed for gyro drift. This novel solution prevents the impact of quartic characteristics and uses the iterative method to meet the requirement of real-time applications. A novel attitude determination algorithm, the pre-process DV-UKF algorithm, is proposed in combination with UKF based on the above solution and its characteristics.

Findings

Compared to UKF, both simulation and experimental results demonstrate that the pre-process DV-UKF algorithm has higher reliability in attitude determination. The dynamic errors in the three directions of the attitude are below 2.0°, the static errors are all less than 0.2° and the absolute attitude errors tailored by average are about 47.98% compared to the UKF.

Originality/value

This paper fulfils an identified need to achieve high-precision attitude estimation when using low-cost inertial devices in micro-quadrotor. The accuracy of the pre-process DV-UKF algorithm is superior to other products in the market.
Development and strength assessment of eco-friendly geopolymer concrete made with natural and recycled aggregates
Authors: Kanagaraj Balamurali , Kiran Tattukolla , N. Anand , Al Jabri Khalifa , S. Justin
Published: March 2022

Purpose

This study aims to develop geopolymer concrete (GPC) using manufactured sand (M-sand) and recycled concrete aggregate (RCA) under different curing conditions. GPC is a sustainable construction material developed with industrial waste products such as fly ash to eliminate the use of cement in the production of concrete. GPC requires heat curing for the attainment of early age strength. The development of GPC under heat curing conditions is a hard process in practice. To overcome such circumstances, an attempt was made to develop the GPC under different curing conditions with the aid of coarse aggregate (CA) and RCA. The influence of different curing conditions on strength gain and microstructural characteristics of GPC is investigated. Mechanical properties of GPC such as compressive strength, tensile strength, flexural strength and elastic modulus are reported and discussed.

Design/methodology/approach

This study focuses on the assessment of mechanical and microstructure characterization of eco-efficient GPC developed with natural CA and RCAs. The required optimum quantity of binder, alkali activator, alkaline liquid to binder ratio and aggregates was determined by appropriate trials. Three types of curing methods, namely, ambient, oven and water, were used for the development of GPC mixes. Following the properties of RCA, it is realistic to substitute up to 40% of coarser aggregates as the resulting aggregate mix falls within the requirements of the analyzed mix.

Findings

Special attention is required for the mix with RCA because the mix’s consistency is affected by the high water absorption of the RCA mix. GPC specimens cured at ambient and water conditions exhibited marginal variation in the compressive strength for both CA and RCA. The compressive strength of GPC mixes prepared with RCA was marginally higher than that of the GPC made with CA under different curing regimes. RCA can be used as a sustainable material in lieu of CA in GPC.

Originality/value

The main significance of this research work is to develop the optimal mix design with appropriate mix proportion. The present study proposes a satisfactory methodology that enhances the mechanical strength of GPC as the guidelines are not available in the standards to address this problem. Effective use of waste materials such as fly ash and recycled aggregate for the development of GPC is another major research focus in the proposed investigation.
Predictors of the dependence on smartphones: the neglect of studies among Muslim students
Authors: Tan Christine Nya-Ling , Fauzi Muhammad Ashraf , Ojo Adedapo Oluwaseyi
Published: March 2022

Purpose

This study aims to posit the extended version of the technology acceptance model to explain the psychological factors of Muslim university students’ smartphone addictive behaviour and neglect of studies. In particular, this research conceptualised addictive behaviour as smartphone dependency and proposed process usage, flow, habitual smartphone behaviour and preference for online social interaction (POSI) as the associated factors. Besides, this study investigated the effect of smartphone dependency on the neglect of studies.

Design/methodology/approach

Following the quantitative research design, this research tested the proposed model using data collected from Muslim students’ smartphone users in Malaysia. The analyses were based on the partial least squares–structural equation modelling technique.

Findings

The results revealed that flow has the most significant influence on smartphone dependency. Habitual behaviour and process usage were also significant predictors, but POSI was not significantly associated with smartphone dependency. Also, smartphone dependency was significantly related to the neglect of studies.

Research limitations/implications

This study provides empirical support to guide university management in preventing Muslim students’ over-dependence on smartphones. The Muslim community is synonymous with time management, where overdependence would diminish students’ religious and academic responsibilities. Such overdependence can cause neglect of studies; thus, the research findings can assist the university in introducing policies and campaigns that can educate students on the negative consequences of this pervasive digital addiction and ways to overcome them. This study contributes to the body of knowledge in understanding Muslim students coping mechanisms through smartphone usage.

Originality/value

This study contributes to the literature by demonstrating the psychological factors of smartphone addiction and the resultant effect on the neglect of studies among Muslim university students.
Does oil price uncertainty affect earnings management? Evidence from GCC markets
Authors: Bugshan Abdullah , Alnahdi Sally , Ananzeh Husam , Alnori Faisal
Published: March 2022

Purpose

Since it is believed that economic growth in oil-rich countries is highly influenced by oil price movements, this study aims to explore the relationship between oil price volatility (uncertainty) and earnings-management decisions.

Design/methodology/approach

Financial data from oil-exporting countries were used to explore the relationship between oil price volatility and earnings-management decisions. The study used univariate and multivariate analysis. The modified Jones model is the proxy accrual earnings management. Further, the standard deviation of daily oil price returns is used to proxy annualised oil price volatility.

Findings

The results show that there is an association between oil price volatility and accrual earnings management. Specifically, there is a positive and significant relationship between negative accruals and oil price volatility, indicating that firms are inclined to conduct income-decreasing earnings management in periods of high oil price volatility.

Research limitations/implications

This study’s findings have important implications for regulators and investors because they indicate that the uncertainty of oil price volatility has an influence on earnings quality in oil-dependent economies. This is especially important considering the ongoing debate on transparency issues.

Originality/value

To the best of the authors’ knowledge, this study is the first to investigate the relationship between oil prices volatility and earning management behaviour for non-financial firms. Further, the study uses unique data of oil-dependent economies.
Metaverse – the new marketing universe
Authors: Hollensen Svend , Kotler Philip , Opresnik Marc Oliver
Published: March 2022

Purpose

This study aims to present and explain the concept of Metaverse, which will revolutionize nearly every industry and can be regarded as the 3D version of the internet. Especially, the paper explores the “building blocks” of the Metaverse and how it is functioning in a case study.

Design/methodology/approach

The Metaverse concept is explained by the Nike–Roblox case study, where the authors explore the customer benefits, that are provided by the Nikeland project.

Findings

The Nike–Roblox case study is showing that virtual platforms, content services, consumer and business behavior are the most important and visible “building blocks” to the Nikeland visitors (customers) in the Nike–Roblox alliance. The Metaverse is gaining popularity among the big global brands. It is expected that the big breakthrough for Metaverse will happen when the next layer of brands, the regional and local brands, will start penetrating the Metaverse.

Originality/value

Metaverse will be the new future marketing platform for presenting and giving life to all kinds of brands in the 3D interactive digital space. Metaverse is a digital copy of how we are working in the physical world. In this 3D digital space, the users can come together via avatars that resemble them. This will have an enormous effect on how companies will use the marketing function and how we will communicate with each other in future.
Traffic signal coordination control for arterials with dedicated CAV lanes
Authors: Xu Liang , Jin Sheng , Li Bolin , Wu Jiaming
Published: March 2022

Purpose

This study aims to make full use of the advantages of connected and autonomous vehicles (CAVs) and dedicated CAV lanes to ensure all CAVs can pass intersections without stopping.

Design/methodology/approach

The authors developed a signal coordination model for arteries with dedicated CAV lanes by using mixed integer linear programming. CAV non-stop constraints are proposed to adapt to the characteristics of CAVs. As it is a continuous problem, various situations that CAVs arrive at intersections are analyzed. The rules are discovered to simplify the problem by discretization method.

Findings

A case study is conducted via SUMO traffic simulation program. The results show that the efficiency of CAVs can be improved significantly both in high-volume scenario and medium-volume scenario with the plan optimized by the model proposed in this paper. At the same time, the progression efficiency of regular vehicles is not affected significantly. It is indicated that full-scale benefits of dedicated CAV lanes can only be achieved with signal coordination plans considering CAV characteristics.

Originality/value

To the best of the authors’ knowledge, this is the first research that develops a signal coordination model for arteries with dedicated CAV lanes.
The impact of advertising appeals on impulse buying
Authors: Deshpande Bilwa , Pradhan Debasis , Sivakumaran Bharadhwaj , Lyngdoh Teidorlang
Published: March 2022

Purpose

The purpose of this paper is to examine the varying impact of advertising appeals on customers’ impulse buying (IB) for vice and virtue products.

Design/methodology/approach

This research used two experiments varying humor/scarcity (high/low) and product category (vice versus virtue).

Findings

Humor (scarcity) enhances IB of vice (virtue) products through anticipation of enjoyment (perception of uniqueness).

Research limitations/implications

This research identifies a new antecedent of IB, advertising and additionally, a new moderator, product type (vice/virtue) in the ad appeal–IB relationship.

Practical implications

Practitioners managing vice (virtue) brands may use humor (scarcity) appeals to promote impulse buying.

Originality/value

This paper demonstrates that humor (scarcity) appeals enhance impulse buying of vice (virtue) products and shows the underlying mechanisms behind these effects.
Motivations to share knowledge in professional service teams: the moderating role of project stage
Authors: Nguyen Ngoc Lan , Phan Anh Thi Thuc , Doan Nga Thanh
Published: March 2022

Purpose

This study aims to examine the effects of three-perspective motivations including task interdependence, normative conformity, affective bonding on team knowledge sharing (KS) and the moderating effects of project stage on the proposed model paths.

Design/methodology/approach

The quantitative method was applied through surveying senior auditors representing 263 audit teams in Vietnam.

Findings

Findings show that task interdependence has salient effect on team KS. Normative conformity and affective bonding become more important when projects move to later stages where knowledge shared is more tacit and the team involves more social interactions.

Research limitations/implications

This study puts forth the limitations related to the study scope of financial statement auditing teams that may influence the generalization.

Practical implications

This study recommends auditing managers to be aware of diverse motivations for team KS and their increasingly important role in specific project stages.

Originality/value

The novelty of the research is to integrate three knowledge-sharing motivations based on economics, social and psychological perspectives and to affirm the dynamic nature of KS within team projects.
Aptness of nano alumina (Al2O3) with high range water reducer-incorporated concrete
Authors: Peerzada Mudasir , Adnan Khan , Bilal Basrah , Janees Riyaz , Qazi Bazila , Javed Naqash Ahmed
Published: March 2022

Purpose

The purpose of this paper is to study the effect of nano alumina (Al2O3) on the properties of fresh concrete, hardened concrete and microstructure of concrete incorporated with high range water reducer (HRWR). This initiative was taken to improve characteristic properties of concrete using nano alumina because nano alumina can be easily be manufactured from a scrap of industrial aluminum products, so its incorporation in concrete will not only reduce industrial aluminum waste but will also change the morphology of concrete at the microstructural level.

Design/methodology/approach

To accomplish the objectives of the research, four different concrete mixes with the constant water–cement ratio (W/C) and superplasticizer (SP) content 0.4 and 0.6% by weight of cement, respectively, were prepared, whereas nano alumina content was altered by 0.3% and 0.4% by weight of cement. Fresh property of concrete was analyzed by using slump cone test, whereas hardened properties of concrete were analyzed through compression test and flexural strength test. The interaction of nano alumina with concrete composite was evaluated using an X-ray diffraction test.

Findings

It was observed that 0.6% superplasticizer by weight of cement increased workability by 22% but with the addition of 0.3%, nano alumina by weight of cement workability decreased by 31%. Compressive strength increased by 4.88% with the addition of 0.6% superplasticizer but with the addition of 0.3% nano alumina by weight of cement compressive strength increased by 18.60%. Also, flexural strength increased by 1.21% with the addition of 0.6% superplasticizer by weight of cement but with the addition of 0.3% nano alumina by weight of cement flexural strength increased by 8.76%. With the addition of superplasticizer, alite and belite phases remained un-hydrated but with the addition of nano alumina alite phase was hydrated while belite phase was un-hydrated. The size of belite crystals in mixes having nano alumina was less than that of mix having 0.6% superplasticizer. Also with the addition of nano alumina, a calcium aluminum silicate phase was formed which was responsible for the increment of strength in mixes having nano alumina.

Originality/value

Incorporation nano alumina (Al2O3) in concrete will not only reduce industrial aluminum waste but will also reduce CO2 emission. Nano alumina (Al2O3) also changes morphology of concrete at micro structural level.