bluuebunny/crossref_metadata_2025 huggingface dataset:
Toxicological impacts and likely protein targets of bisphenol A in Paramecium caudatum
Authors: Senra Marcus V. X. , Lúcia Fonseca Ana
Published: June 2021

Bisphenol A (BPA) is a chemical agent widely used in plastic production and a well-known ubiquitous endocrine disruptor, frequently associated with a series of reproductive, developmental, and transgenerational impacts over wildlife, livestocks, and humans. Although widely studied, toxicological data on the effects of BPA are mostly restricted to mammalian models, remaining largely underexplored for other groups of organisms such as protists, which represents a considerable proportion of eukaryotic diversity. Here, we used acute end-point toxicological assay to evaluate the impacts of BPA over the survival of the cosmopolitan Paramecium caudatum; and a proteome-wide inverted virtual-screening (IVS) to predict the most likely P. caudatum proteins and pathways affected by BPA. This xenobiotic exerts a time-dependent effect over P. caudatum survival, which may be a consequence of impairments to multiple core cellular functions. We discuss the potential use of this ciliate as a biosensor for environmental BPA and as a new model organism to study the general impacts of this plasticizer agent over Eukaryotes. Finally, our data stress the relevance of bioinformatic methods to leverage the current knowledge on the molecular impacts of environmental contaminants over a diversity of biological systems.
Short-term facilitation of long-range corticocortical synapses revealed by selective optical stimulation
Authors: Martinetti Luis E. , Bonekamp Kelly E. , Autio Dawn M. , Kim Hye-Hyun , Crandall Shane R.
Published: June 2021

Short-term plasticity regulates the strength of central synapses as a function of previous activity. In the neocortex, direct synaptic interactions between areas play a central role in cognitive function, but the activity-dependent regulation of these long-range corticocortical connections and their impact on a postsynaptic target neuron is unclear. Here, we use an optogenetic strategy to study the connections between mouse primary somatosensory and motor cortex. We found that short-term facilitation was strong in both corticocortical synapses, resulting in far more sustained responses than local intra-cortical and thalamocortical connections. A major difference between pathways was that the synaptic strength and magnitude of facilitation were distinct for individual excitatory cells located across all cortical layers and specific subtypes of GABAergic neurons. Facilitation was dependent on the presynaptic calcium sensor synaptotagmin-7 and altered by several optogenetic approaches. Current-clamp recordings revealed that during repetitive activation, the short-term dynamics of corticocortical synapses enhanced the excitability of layer 2/3 pyramidal neurons, increasing the probability of spiking with activity. Furthermore, the properties of the connections linking primary with secondary somatosensory cortex resemble those between somatosensory-motor areas. These short-term changes in transmission properties suggest long-range corticocortical synapses are specialized for conveying information over relatively extended periods.
Design and validation of a multi-point injection technology for MR-guided convection enhanced delivery in the brain
Authors: Prezelski Kayla , Keiser Megan , Stein Joel M. , Lucas Timothy H. , Davidson Beverly , Gonzalez-Alegre Pedro , Vitale Flavia
Published: June 2021

Convection enhanced delivery (CED) allows direct intracranial administration of neuro-therapeutics. Success of CED relies on specific targeting and broad volume distributions (VD). However, to prevent off-target delivery and tissue damage, CED is typically conducted with small cannulas and at low flow rates, which critically limit the maximum achievable VD. Furthermore, in applications such as gene therapy requiring injections of large fluid volumes into broad subcortical regions, low flow rates translate into long infusion times and multiple surgical trajectories. The cannula design is a major limiting factor in achieving broad VD, while minimizing infusion time and backflow. Here we present and validate a novel multi-point cannula specifically designed to optimize distribution and delivery time in MR-guided intracranial CED of gene-based therapeutics. First, we evaluated the compatibility of our cannula with MRI and common viral vectors for gene therapy. Then, we conducted CED tests in agarose brain phantoms and benchmarked the results against single-needle delivery. 3T MRI in brain phantoms revealed minimal susceptibility-induced artifacts, comparable to the device dimensions. Benchtop CED of adeno-associated virus demonstrated no viral loss or inactivation. CED in agarose brain phantoms at 3, 6, and 9 μL/min showed >3x increase in volume distribution and 60% time reduction compared to single-needle delivery. This study confirms the validity of a multi-point delivery approach for improving infusate distribution at clinically-compatible timescales and supports the feasibility of our novel cannula design for advancing safety and efficacy of MR-guided CED to the central nervous system.
Distinct Hippocampal Neuronal Reactions Reveal Different Neuronal Codes for Memory Generalization
Authors: Guo Jun , Truong Duc , Barreiro Andrea , Lin Da-Ting , Xu Wei
Published: June 2021

To survive in an ever-changing world we need to learn and memorize associations of environmental stimuli and generalize them to new situations. Both memory and generalization critically rely on the hippocampus, but it is unclear how hippocampal neuronal activities represent memory and generalization, and if a conserved hippocampal mechanism serves these functions. Here we compared neuronal activities in hippocampal CA1 region of two sub-strains of the widely used C57BL/6 mice, C57BL/6J (B6J) and C57BL/6NCrl (B6NCrl), in contextual fear conditioning. Both sub-strains learnt well but differed in freezing and generalization. They displayed distinct early-late bi-phasic reactions to the unconditioned stimulus. While in both sub-strains the neurons showing late-phase reactions were preferentially engaged in memory representation, the neuronal activity feature that correlated with generalization level differed in the two sub-strains: in B6NCrl, these neurons’ activity level during learning negatively correlated with the generalization level; in B6J, functional coupling of these late-phase neurons with other neurons positively correlated with the generalization level. We further found that the distinct neuronal reactions were accompanied by distinct GABAb receptor-mediated inhibition but not by differences in the major synaptic inputs or neuronal excitability of the CA1. Therefore, this comparative study reveals two signature neuronal activity features in learning that can predict generalization levels. The results also demonstrate that differences in hippocampal network properties lead to diverse hippocampal mechanisms in memory encoding and generalization.
In vitro and in vivo co-infection and super-infection dynamics of Mayaro and Zika viruses in mosquito and vertebrate backgrounds
Authors: Brustolin Marco , Pujhari Sujit , Henderson Cory A. , Kim Donghun , Rasgon Jason L.
Published: June 2021

Factors related to increasing globalization and climate change have contributed to the simultaneous increase and spread of arboviral diseases. Co-circulation of multiple arboviruses in the same geographic regions provides impetus to study the impacts of multiple arbovirus infections in a single vector. In the present study we describe co-infection and super-infection with Mayaro virus (Family Togaviridae, genus Alphavirus) and Zika virus (family Flaviviridae, genus Flavivirus) in vertebrate cells, mosquito cells, and Aedes aegypti mosquitoes to understand the interaction dynamics of these pathogens and effects on viral infection, dissemination and transmission. In Aedes aegypti mosquitoes, co-infection has a negative impact on infection and dissemination rates for Zika virus, but not Mayaro virus, when compared to single infection scenarios, and super-infection of Mayaro virus with a previous Zika virus infection resulted in increased Mayaro virus infection rates. We found that co-infection and super-infection negatively affected Zika viral replication in vertebrate cells (Vero and Huh), resulting in the complete blockage of Zika virus replication in some scenarios. At the cellular level, we demonstrate that single vertebrate and insect cells can be simultaneously infected with Zika and Mayaro viruses. This study highlights the dynamics of arboviral co- and super-infections and emphasizes the importance of considering these dynamics during risk assessment in epidemic areas.
Discovery and visualization of uncharacterized drug-protein adducts using mass spectrometry
Authors: Riffle Michael , Hoopmann Michael R. , Jaschob Daniel , Zhong Guo , Moritz Robert L. , MacCoss Michael J. , Davis Trisha N. , Isoherranen Nina , Zelter Alex
Published: June 2021

Drugs are often metabolized to reactive intermediates that form protein adducts. Adducts can inhibit protein activity, elicit immune responses, and cause life threatening adverse drug reactions. The masses of reactive metabolites are frequently unknown, rendering traditional mass spectrometry-based proteomics incapable of adduct identification. Here, we present Magnum, an open-mass search algorithm optimized for adduct identification, and Limelight, a web-based data processing package for analysis and visualization of data from all existing algorithms. Limelight incorporates tools for sample comparisons and xenobiotic-adduct discovery. We validate our tools with two drug/protein combinations and apply our workflow to identify novel xenobiotic-protein adducts in CYP3A4. Our new methods and software enable accurate identification of xenobiotic-protein adducts with no prior knowledge of adduct masses or protein targets. Magnum outperforms existing tools in xenobiotic-protein adduct discovery, while Limelight fulfills a major need in the rapidly developing field of open-mass searching, which until now lacked comprehensive data visualization tools.
c-di-GMP inhibits early sporulation in Clostridioides difficile
Authors: Edwards Adrianne N. , Willams Caitlin L. , Pareek Nivedita , McBride Shonna M. , Tamayo Rita
Published: June 2021

The formation of dormant spores is essential for the anaerobic pathogen Clostridioides difficile to survive outside of the host gastrointestinal tract. The regulatory pathways and environmental signals that initiate C. difficile spore formation within the host are not well understood. One bacterial second messenger signaling molecule, cyclic diguanylate (c-di-GMP), modulates several physiological processes important for C. difficile pathogenesis and colonization, but the impact of c-di-GMP on sporulation is unknown. In this study, we investigated the contribution of c-di-GMP to C. difficile sporulation. Overexpression of a gene encoding a diguanylate cyclase, dccA, decreased sporulation frequency and early sporulation gene transcription in both the epidemic R20291 and historical 630Δerm strains. Expression of a dccA allele encoding a catalytically inactive DccA that is unable to synthesize c-di-GMP no longer inhibited sporulation, indicating that the accumulation of intracellular c-di-GMP reduces C. difficile sporulation. A null mutation in dccA slightly increased sporulation in R20291 and slightly decreased sporulation in 630Δerm, suggesting that DccA may contribute to the intracellular pool of c-di-GMP in a strain-dependent manner. However, these data were highly variable, underscoring the complex regulation involved in modulating intracellular c-di-GMP concentrations. Finally, overexpression of dccA in known sporulation mutants revealed that c-di-GMP is likely signaling through an unidentified regulatory pathway to control early sporulation events in C. difficile. C-di-GMP-dependent regulation of C. difficile sporulation may represent an unexplored avenue of potential environmental and intracellular signaling that contributes to the complex regulation of sporulation initiation.

IMPORTANCE

Many bacterial organisms utilize the small signaling molecule cyclic diguanylate (c-di-GMP) to regulate important physiological processes, including motility, toxin production, biofilm formation, and colonization. C-di-GMP inhibits motility and toxin production and promotes biofilm formation and colonization in the anaerobic, gastrointestinal pathogen Clostridioides difficile. However, the impact of c-di-GMP on C. difficile spore formation, a critical step in this pathogen’s life cycle, is unknown. Here, we demonstrate that c-di-GMP negatively impacts sporulation in two clinically relevant C. difficile strains, the epidemic R20291 and the historical 630Δerm. The pathway through which c-di-GMP controls sporulation was investigated, and our results suggest that c-di-GMP is likely signaling through an unidentified regulatory pathway to control C. difficile sporulation. This work implicates c-di-GMP metabolism as a potential mechanism to integrate environmental and intracellular cues through c-di-GMP levels to influence C. difficile sporulation.
Genome-wide identification and characterization of DNA/RNA differences associated with Fusarium graminearum infection in wheat
Authors: Yang Guang , Pan Yan , Zhang Ruoyu , Huang Jiaqian , Pan Wenqiu , Cui Licao , Song Weining , Nie Xiaojun
Published: June 2021

RNA editing (DNA/RNA differences) as a post-transcriptional modification approach to enrich genetic information, plays the crucial role in regulating diverse biological processes in eukaryotes. Although it has been extensively studied in plant chloroplast and mitochondria genome, RNA editing in plant nuclear genome, especially those associated with Fusarium head blight (FHB), is not well studied at present. Here, we investigated the DNA/RNA differences associated with FHB through a novel method by comparing the RNA-seq data from Fusarium-infected and control samples from 4 wheat genotypes. A total of 187 DNA/RNA differences were identified in 36 wheat genes, representing the first landscape of the FHB-responsive RNA editome in wheat. Furthermore, all of these 36 edited genes were located in the FHB related co-expression gene modules, which may involve in regulating FHB response. Finally, the effects of DNA/RNA differences were systematically investigated to show that they could cause the change of RNA structure and protein structure in edited genes. In particular, the G to C editing (chr3A_487854715) in TraesCS3A02G263900, which is the orthology of OsRACK1, resulted that it was targeted by tae-miR9664-3p to control its expression in different genotype through different editing efficiency, suggesting RNA editing could mediate miRNA to participate in the regulation network of FHB tolerance. This study reported the first wheat DNA/RNA differences associated with FHB, which not only contribute to better understand the molecular basis underlying FHB tolerance, but also shed light on improving FHB tolerance through epigenetic method in wheat and beyond.
A random priming amplification method for whole genome sequencing of SARS-CoV-2 and H1N1 influenza A virus
Authors: Chrzastek Klaudia , Tennakoon Chandana , Bialy Dagmara , Freimanis Graham , Flannery John , Shelton Holly
Published: June 2021

Background

Non-targeted whole genome sequencing is a powerful tool to comprehensively identify constituents of microbial communities in a sample. There is no need to direct the analysis to any identification before sequencing which can decrease the introduction of bias and false negatives results. It also allows the assessment of genetic aberrations in the genome (e.g., single nucleotide variants, deletions, insertions and copy number variants) including in noncoding protein regions.

Methods

The performance of four different random priming amplification methods to recover RNA viral genetic material of SARS-CoV-2 were compared in this study. In method 1 (H-P) the reverse transcriptase (RT) step was performed with random hexamers whereas in methods 2-4 RT incorporating an octamer primer with a known tag. In methods 1 and 2 (K-P) sequencing was applied on material derived from the RT-PCR step, whereas in methods 3 (SISPA) and 4 (S-P) an additional amplification was incorporated before sequencing.

Results

The SISPA method was the most effective and efficient method for non-targeted/random priming whole genome sequencing of COVID that we tested. The SISPA method described in this study allowed for whole genome assembly of SARS-CoV-2 and influenza A(H1N1)pdm09 in mixed samples. We determined the limit of detection and characterization of SARS-CoV-2 virus which was 103 pfu/ml (Ct, 22.4) for whole genome assembly and 101 pfu/ml (Ct, 30) for metagenomics detection.

Conclusions

The SISPA method is predominantly useful for obtaining genome sequences from RNA viruses or investigating complex clinical samples as no prior sequence information is needed. It might be applied to monitor genomic virus changes, virus evolution and can be used for fast metagenomics detection or to assess the general picture of different pathogens within the sample.
BayesDeBulk: A Flexible Bayesian Algorithm for the Deconvolution of Bulk Tumor Data
Authors: Petralia Francesca , Krek Azra , Calinawan Anna P. , Charytonowicz Daniel , Sebra Robert , Feng Song , Gosline Sara , Pugliese Pietro , Paulovich Amanda G. , Kennedy Jacob J. , Ceccarelli Michele , Wang Pei
Published: June 2021

To understand immune activation and evasion mechanisms in cancer, one crucial step is to characterize the composition of immune and stromal cells in the tumor microenvironment (TME). Deconvolution analysis based on bulk transcriptomic data has been used to estimate cell composition in TME. However, these algorithms are sub-optimal for proteomic data, which has hindered research in the rapidly growing field of proteogenomics. Moreover, with the increasing prevalence of multi-omics studies, there is an opportunity to enhance deconvolution analysis by utilizing paired proteomic and transcriptomic profiles of the same tissue samples. To bridge these gaps, we propose BayesDeBulk, a new method for estimating the immune/stromal cell composition based on bulk proteomic and gene expression data. BayesDeBulk utilizes the information of known cell-type-specific markers without requiring their absolute abundance levels as prior knowledge. We compared BayesDeBulk with existing tools on synthetic and real data examples, demonstrating its superior performance and versatility.

Availability

Software available athttp://www.BayesDeBulk.com/

Contact

For any information, please contactfrancesca.petralia@mssm.edu
Genomic miscellany and allelic frequencies of Plasmodium falciparum msp-1, msp-2 and glurp in parasite isolates
Authors: Ullah Ibrar , Afridi Sahib Gul , Ullah Asif , Israr Muhammad , Ali Anwar , Jabeen Hina , Rasool Akhtar , Akbar Fazal , Shah Muzafar
Published: June 2021

The genomic miscellany of malaria parasites can inform the intensity of transmission and identify potential deficiencies in malaria control programs. The aim of this study was to investigate the genomic miscellany, allele frequencies and multiplicity of infection (MOI) of P. falciparum.

Methods

A total of 85 isolates from patients presenting to the local health centers with P. falciparum species were collected from 2017 to 2019. Parasite DNA was extracted from a total of 200 µl whole blood per patient using the Qiagen DNA extraction kit according to manufactures instructions. The polymorphic region of msp-1, msp-2 and glurp loci were genotyped by using nested polymerase chain reactions followed by gel electrophoresis for fragment analysis.

Results

Genetic diversity and allelic frequencies of msp-1, msp-2 and glurp were identified in 85 blood samples. A total of 62 msp alleles were detected in which 30 for msp-1 and 32 for msp-2. For msp-1 the successful amplification occurred in (75/85) 88.23% isolates for msp-1, 78.9% (67/85) for msp-2 and 70% (60/85) for glurp. For msp-1, the K1 allelic family was predominant at 66.66% (50/75), followed by RO33 and MAD20. The frequency of samples having only K1, MAD20 and RO33 were 21.34% (16/75), 8% (6/75) and 10.67% (8/75) respectively. In msp-2, the FC27 allelic family was the most abundant with 70.14% (47/67) compared to 3D7 with 67.16% (45/67). Nine glurp RII region genotypes were identified. The overall mean multiplicity of infection was 2.6 with1.8 and 1.4 for msp-1 and msp-2 respectively while for glurp RII genes (MOI=1.03). There was no significant association between multiplicity of infection and age group (Spearman’s rank coefficient = 0.050; P = 0.6). There was significant correlation between MOI and parasite density for msp-2 allelic family.

Conclusion

Our study showed high genetic diversity and allelic frequency with multiple clones of msp-1, msp-2 and glurp in P. falciparum isolates from malaria patients in Khyber Pakhtunkhwa Pakistan. In the present study the genotype data provided the valuable information which is essential for monitoring the impact of malaria eradication efforts in this region.
Essential role of translation factor eIF5a in cytokine production and cell cycle regulation in primary CD8 T lymphocytes
Authors: Tan Thomas CJ , Kelly Van , Zhou Xiaoyan , Ly Tony , Zamoyska Rose
Published: June 2021

Translational control adjusts protein production rapidly and facilitates local cellular responses to environmental conditions. Translation can be regulated through sequestration of mRNAs by regulatory proteins or RNAs, but also by the availability of ribosomes and translation factors which enable initiation and elongation of nascent polypeptides. Traditionally initiation of mRNA translation has been considered to be a major translational control point, however, control of peptide elongation can also play a role. Here we show that post-translational modification of the elongation factor, eIF5a, controls translation of subsets of proteins in naïve T-cells upon activation. Sequencing of nascent polypeptides indicated that functional eIF5a was required for the production of proteins which regulate T-cell proliferation and effector function. Control of translation in multiple immune cell lineages is required to co-ordinate immune responses and these data illustrate that translational elongation can contribute to post-transcriptional regulons important for the control of inflammation.
Precancer: Mutant clones in normal epithelium outcompete and eliminate esophageal micro-tumors
Authors: Colom B. , Herms A. , Hall M.W.J. , Dentro S.C. , King C. , Sood R.K. , Alcolea M.P. , Piedrafita G. , Fernandez-Antoran D. , Ong S.H. , Fowler J.C. , Mahbubani K.T. , Saeb-Parsy K. , Gerstung M. , Hall B.A. , Jones P.H.
Published: June 2021

Human epithelial tissues accumulate cancer-driver mutations with age1–7, yet tumor formation remains rare. The positive selection of these mutations argues they alter the behavior and fitness of proliferating cells8–10. Hence, normal adult tissues become a patchwork of mutant clones competing for space and survival, with the fittest clones expanding by eliminating their less-competitive neighbors9–12. However, little is known about how such dynamic competition in normal epithelia impacts early tumorigenesis. Here we show that the majority of newly formed esophageal tumors are eliminated through competition with mutant clones in the surrounding normal epithelium. We followed the fate of microscopic tumors in a mouse model of esophageal carcinogenesis. Most neoplasms are rapidly lost despite no indication of tumor cell death, decreased proliferation, or an anti-tumor immune response. Deep-sequencing of 10-day and 1-year-old tumors shows evidence of genetic selection on the surviving neoplasms. Induction of highly competitive clones in transgenic mice increased tumor removal, while pharmacologically inhibiting clonal competition reduced tumor loss. The results are consistent with a model where survival of early neoplasms depends on their competitive fitness relative to that of mutant clones in the adjacent normal tissue. We have identified an unexpected anti-tumorigenic role for mutant clones in normal epithelium by purging early neoplasms through cell competition, thereby preserving tissue integrity.
The Personalized Cancer Network Explorer (PeCaX) as a visual analytics tool to support molecular tumor boards
Authors: Figaschewski Mirjam , Sürün Bilge , Tiede Thorsten , Kohlbacher Oliver
Published: June 2021

Background

Personalized oncology represents a shift in cancer treatment from conventional methods to target specific therapies where the decisions are made based on the patient specific tumor profile. Selection of the optimal therapy relies on a complex interdisciplinary analysis and interpretation of these variants by experts in molecular tumor boards. With up to hundreds of somatic variants identified in a tumor, this process requires visual analytics tools to guide and accelerate the annotation process.

Results

The Personal Cancer Network Explorer (PeCaX) is a visual analytics tool supporting the efficient annotation, navigation, and interpretation of somatic genomic variants through functional annotation, drug target annotation, and visual interpretation within the context of biological networks. Starting with somatic variants in a VCF file, PeCaX enables users to explore these variants through a web-based graphical user interface. The most protruding feature of PeCaX is the combination of clinical variant annotation and gene-drug networks with an interactive visualization. This reduces the time and effort the user needs to invest to get to a treatment suggestion and helps to generate new hypotheses. PeCaX is being provided as a platform-independent containerized software package for local or institution-wide deployment. PeCaX is available for download athttps://github.com/KohlbacherLab/PeCaX-docker.
Tools for supporting solution scattering during the COVID-19 pandemic
Authors: Yang Lin , Lazo Edwin , Byrnes James , Chodankar Shirish , Antonelli Stephen , Rakitin Maksim
Published: June 2021

During the COVID-19 pandemic, synchrotron beamlines were forced to limit user access. Performing routine measurements became a challenge. At the Life Science X-ray Scattering (LiX) beamline, new instrumentation and mail-in protocols have been developed to remove the access barrier to solution scattering measurements. Our efforts took advantage of existing instrumentation and coincided with the larger effort at NSLS-II to support remote measurements. Given the limited staff–user interaction for mail-in measurements, additional software tools have been developed to ensure data quality, to automate the adjustments in data processing, as users would otherwise rely on the experience of the beamline staff, and produce a summary of the initial assessments of the data. This report describes the details of these developments.
Crystal structure and Hirshfeld surface analysis of ethyl 2-({5-acetyl-3-cyano-6-methyl-4-[(E)-2-phenylethenyl]pyridin-2-yl}sulfanyl)acetate
Authors: Al-Waleedy Safiyyah A. H. , Mohamed Shaaban K. , Mague Joel T. , Akkurt Mehmet , Abbady Mohamed S. , Bakhite Etify A.
Published: June 2021

In the title molecule, C21H20N2O3S, the styryl and ester substituents are displaced to opposite sides of the plane of the pyridine ring. In the crystal, C—H...O hydrogen bonds form chains extending parallel to the a-axis direction, which pack with partial intercalation of the styryl and ester substituents. A Hirshfeld surface analysis indicates that the most significant contributions to the crystal packing are from H...H (43.6%), C...H/H...C (15.6%), O...H/H...O (14.9%) and N...H/H...N (11.2%) contacts.
Push recovery control for the underactuated lower extremity exoskeleton based on improved capture point concept
Authors: Zhang Jiaqi , Cong Ming , Liu Dong , Du Yu , Ma Hongjiang
Published: June 2021

Purpose

The purpose of this paper is to use a simple method to enhance the ability of lower limb exoskeletons to restore balance under large interference conditions and to solve the problem that biped robot stability criterion cannot be fully applied to the underactuated lower limb exoskeletons.

Design/methodology/approach

The method used in this paper is to construct an underactuated lower extremity exoskeleton ankle joint with a torsion spring. Based on the constructed exoskeleton, the linear inverted torsion spring pendulum model is proposed, and the traditional capture point (CP) concept is optimized.

Findings

The underactuated exoskeleton ankle joint with torsion springs, combined with the improved CP concept, can effectively reduce the forward stepping distance under the same interference condition, which is equivalent to enhancing the balance ability of the lower extremity exoskeleton.

Originality/value

The contribution of this paper is to enhance the balance ability of the exoskeleton of the lower limbs under large interference conditions. The torsion spring is used as the exoskeleton ankle joint, and the traditional CP concept is optimized according to the constructed exoskeleton.
Integration effects of UAVs in non-segregated airspace
Authors: Savas Tamer , Usanmaz Oznur , Sahin Ozlem , Çınar Ertan , Karaderili Murat
Published: June 2021

Purpose

The study aims to design a new route model for unmanned aerial vehicles (UAVs) to integrate them into non-segregated airspace.

Design/methodology/approach

The proposed route model was assessed and validated through real-time simulations.

Findings

The comparison results of baseline and proposed route model show that a reduction of 38% and 41% in the total flight time and total flight distance were obtained in favour of the proposed model, respectively.

Practical implications

The proposed route model can be applied by airspace designers and UAV users to perform safe and efficient landing in non-segregated airspace.

Originality/value

In this study, a new proposed route model is constructed for UAVs. Quantitative results, using a real-time simulation method, are achieved in terms of flight distance and flight time.
Do high-reputation companies pay more non-audit fees?
Authors: Huang Xuan , Kang Fei
Published: June 2021

Purpose

The purpose of this study is to investigate the association between companies’ reputation and their purchase of non-audit services (NAS).

Design/methodology/approach

This study measures company reputation using the reputation scores from Fortune’s “America’s Most Admired Companies” list. Multivariate analysis is performed to examine the association between public companies’ overall reputation and their decision of NAS purchase. Robustness checks are performed to control for self-selection bias and alternate measures are used to proxy for company reputation and NAS fees.

Findings

This study finds that high-reputation companies on average pay more NAS fees than their counterparts. The results suggest that due to less severe agency conflicts, high-reputation companies tend to purchase more NAS from their incumbent auditors to appreciate the potential benefits of the auditors’ knowledge spillovers.

Originality/value

The findings of this study on the association between company reputation and NAS fees contribute to the literature by providing additional insight on the factors influencing companies’ NAS purchases. The results of this study suggest that a unique company-level characteristic, company reputation, is significantly associated with companies’ NAS purchase, and therefore has both policy and practical implications for the demand of NAS. This study also adds to the growing literature on the influence of company reputation on corporate behavior by documenting the important role that company reputation plays in the managerial decision-making process.
Evaluation of supply chain resilience index: a graph theory based approach
Authors: Agarwal Nishtha , Seth Nitin , Agarwal Ashish
Published: June 2021

Purpose

The present study aims at developing a model to quantify supply chain resilience as a single numerical value. The numerical value is called resilience index that measures the resilience capability of the case company's supply chain. The model calculates the index value based on the interactions between the enablers of supply chain resilience and its dimensions.

Design/methodology/approach

Graph theoretic approach (GTA) is used to evaluate the resilience index for the case company's supply chain. In GTA, the dimensions of resilience enablers and their interdependencies are modelled through a digraph. The digraph depicting the influence of each dimension is converted into an adjacency matrix. The permanent function value of the adjacency matrix is called the resilience index (RI).

Findings

The proposed approach has been illustrated in context of an Indian automobile organization, and value of the RI is evaluated. The best case and the worst-case values are also obtained with the help of GTA. It is noted from the model that strategic level dimension of enablers is most important in contributing towards supply chain resilience. They are followed by tactical and operational level enablers. The GTA framework proposed will help supply chain practitioners to evaluate and benchmark the supply chain resilience of their respective organizations with the best in the industry.

Originality/value

A firm can compare the RI of its own supply chain with other's supply chain or with the best in the industry for benchmarking purpose. Benchmarking of resilience will help organizations in developing strategies to compete in dynamic market scenario.
Application of stacking ensemble machine learning algorithm in predicting the cost of highway construction projects
Authors: Meharie Meseret Getnet , Mengesha Wubshet Jekale , Gariy Zachary Abiero , Mutuku Raphael N.N.
Published: June 2021

Purpose

The purpose of this study to apply stacking ensemble machine learning algorithm for predicting the cost of highway construction projects.

Design/methodology/approach

The proposed stacking ensemble model was developed by combining three distinct base predictive models automatically and optimally: linear regression, support vector machine and artificial neural network models using gradient boosting algorithm as meta-regressor.

Findings

The findings reveal that the proposed model predicted the final project cost with a very small prediction error value. This implies that the difference between predicted and actual cost was quite small. A comparison of the results of the models revealed that in all performance metrics, the stacking ensemble model outperforms the sole ones. The stacking ensemble cost model produces 86.8, 87.8 and 5.6 percent more accurate results than linear regression, vector machine support, and neural network models, respectively, based on the root mean square error values.

Research limitations/implications

The study shows how stacking ensemble machine learning algorithm applies to predict the cost of construction projects. The estimators or practitioners can use the new model as an effectual and reliable tool for predicting the cost of Ethiopian highway construction projects at the preliminary stage.

Originality/value

The study provides insight into the machine learning algorithm application in forecasting the cost of future highway construction projects in Ethiopia.
Kaya FM: the challenge of an afropolitan positioning
Authors: Quaye Emmanuel Silva , Saini Yvonne
Published: June 2021

Learning outcomes

Amongst other things, at the end of this case discussion, the student should be able to: diagnose situational factors that contribute to a brand’s positioning; explore important issues in implementing brand positioning strategies; use relevant models for understanding a firm’s internal and external environments to inform strategic decisions about customers and competition; demonstrate an understanding of target audience; identify the unique attributes of the competition to inform a firm’s positioning and competitive strategy.

Case overview/synopsis

Kaya FM derives its name from the isiZulu word “ikhaya”, which means “home”. The name reflects the mission of the radio station to provide a home for black South Africans who were denied many opportunities during the apartheid era in South Africa. Kaya FM has been broadcasting since 1997, following the deregulation of the media landscape in South Africa. However, by 2018, the radio landscape has become very challenging. Mainstream advertisers still do not consider Kaya FM as a preferred channel to reach their target audience. Overall, radio listenership is dwindling and advertising sales growth is not encouraging. Greg Maloka, Kaya FM’s station manager is considering how to preserve the station’s unique positioning as it competes with both more dominant stations and new entrants so that Kaya FM can truly be a home for Afropolitans for many years to come.

Complexity academic level

Honour’s and master’s level, as well as executive education delegates.

Supplementary materials

Teaching Notes are available for educators only.

Subject code

CSS 8: Marketing.
Washup: aspiring to empower Pakistan’s informal workers
Authors: Fareed Muhammad , Taimoor Sadaf
Published: June 2021

Learning outcomes

Learn the application of important strategy frameworks such as PESTLE, SWOT and Porter’s five forces. Understand the theoretical underpinnings of services marketing and learn the art of developing service blueprints. Critically evaluate the use of change management strategies to induce behavioral change among employees. Appreciate the balance that social enterprises need to achieve between their commercial and social impact goals. Critically evaluate the decision of outsourcing core competencies.

Case overview/synopsis

In 2019, Abbas Jaffery and Sumair Saleem, founders of Washup, Pakistan, a young venture providing on-demand, high-quality and cost-effective laundry service faced a critical management dilemma as their supply chain collapsed due to a rampant surge in demand. The demand surge had been the outcome of Washup’s effort to push its services to the customers by getting vetted by a social media influencer. However, the duo was caught off guard when their supply chain could not meet the sudden increase in demand. The hesitant behavior of the informal workers to join hands with Washup had not only cost Washup this management nightmare but even left the duo at wits ends to develop a strategy that would help gain business idea acceptance from the grass root workers to whom the core competencies of washing and ironing were being outsourced. This case is a rich description of the nuances of operating an unconventional social enterprise in an emerging market and gives an insight on how behavioral change among key workers is critical in ensuring the success of ventures.

Complexity academic level

This case is geared toward undergraduate students enrolled in courses of entrepreneurship, strategy and services marketing.

Supplementary materials

Teaching Notes are available for educators only.

Subject code

CSS 11: Strategy.
A multilevel perspective on the perceived effects of COVID-19 on nurses in China
Authors: Sun Mengyao , Hennekam Sophie
Published: June 2021

Purpose

This study examines the effects of COVID-19 on individual, organizational and societal level as perceived by nurses in China.

Design/methodology/approach

We draw on two qualitative studies consisting of 483 qualitative surveys and 28 in-depth interviews with nurses in China.

Findings

The pandemic has enhanced the profile of the nursing profession in Chinese society and has led to an increase in recognition, respect and visibility of nurses. In addition, participants point to an improved workplace culture in which there is a strong sense of pride in the collective effort they put. Simultaneously, however, nurses reported how COVID-19 was perceived to be detrimental to their own psychological well-being, while also interfering with their work–life balance.

Originality/value

The data reveal the paradoxal effects of COVID-19 on nurses in China. On societal and organizational level, the pandemic seems to have had a positive effect, while on individual level a range of perceived negative effects is identified.
Emotional intelligence and job performance in the hospitality industry: a meta-analytic review
Authors: Miao Chao , Humphrey Ronald H. , Qian Shanshan
Published: June 2021

Purpose

Hospitality workers are emotional labor workers because they must display appropriate emotions to their customers to provide outstanding service. Emotional intelligence (EI) helps employees regulate their emotions and display appropriate emotions, and hence should help hospitality workers provide outstanding service. However, the strength of the relationship between EI and hospitality workers’ job performance substantially varied across studies. Hence, the purpose of the present study is to clarify the mixed findings and to examine if EI can improve hospitality workers’ job performance.

Design/methodology/approach

A meta-analysis was performed to investigate the relationship between EI and hospitality workers’ job performance as well as the moderators which condition this relationship.

Findings

The present meta-analysis indicated that EI is positively related to hospitality workers’ job performance (ρ̅̂ = 0.54); the relationship between EI and hospitality workers’ job performance is stronger when the percentage of married subjects is low and in feminine cultures; and this relationship does not differ between male-dominated and female-dominated studies, across educational levels, between collectivistic and individualistic cultures, between low and high power distance cultures and between low and high uncertainty avoidance cultures.

Research limitations/implications

This study uncovers theoretically important moderators that contribute to cross-cultural research, work–family literature and gender-related literature in hospitality research.

Originality/value

The present study builds a theoretical foundation and performs a meta-analysis to elucidate the relationship between EI and hospitality workers’ job performance and to identify the moderators which condition this relationship.
Collaborative risk management in decentralised multi-tier global food supply chains: an exploratory study
Authors: Cao Shoufeng , Bryceson Kim , Hine Damian
Published: June 2021

Purpose

The aim of this paper is to explore the value of collaborative risk management in a decentralised multi-tier global fresh produce supply chain.

Design/methodology/approach

This study utilised a mixed methods approach. A qualitative field study was conducted to examine the need for collaborative risk management. The simulation experiments with industry datasets were conducted to assess whether risk-sharing contracts work in mitigating joint risks in parts of and across the supply chain.

Findings

The qualitative field study revealed risk propagation and the inefficiency of company-specific risk management strategies in value delivery. The simulation results indicated that risk-sharing contracts can incentivise various actors to absorb interrelated risks for value creation.

Research limitations/implications

The research is limited to risks relevant to supply chain processes in the Australia–China table grrape supply chain and does not consider product-related risks and the risk-taking behaviours of supply chain actors.

Practical implications

Collaborative risk management can be deployed to mitigate systematic risks that disrupt global fresh produce supply chains. The results offer evidence-based knowledge to supply chain professionals in understanding the value of collaborative risk assessment and management and provide insights on how to conduct collaborative risk management for effective risk management.

Originality/value

The results contribute to the supply chain risk management literature by new collaborative forms for effective risk management and strategic competition of “supply chain to supply chain” in multi-tier food supply chains.
A performance measurement system for public–private partnerships: integrating stakeholder influence and process trans-period effect
Authors: Wang Dan , Wang Xueqing , Wang Lu , Liu Henry J. , Jia Xiajie
Published: June 2021

Purpose

The purpose of this study is for examining the evolution of stakeholder influence and the trans-period effect (TPE) of process performance of public–private partnerships (PPPs). TPE refers to the ripple effect of project performance across different phases of a PPP.

Design/methodology/approach

Social network analysis is used to analyze each stakeholder’s influence on PPP performance. For examining the TPE, partial least squares structural equation modelling is conducted.

Findings

The performance in the five phases (e.g. initiation and planning, procurement, construction, operation and transition) of PPPs exhibits significant TPE. The stakeholder network varies in different phases. The most influential stakeholder is a public authority, followed by a public initiator and a private consortium.

Research limitations/implications

The project type of PPPs is not considered in the stakeholder network analysis. Future work should focus on developing a multidimensional stakeholder network by considering the typology of the project. Moreover, the TPE cannot reflect the relationships between the KPIs in the different phases, and thus, further study is required.

Practical implications

This research provides a useful tool for measuring the life cycle outputs and outcomes of PPPs through enhanced process-oriented performance measurement. The developed PMS enable practitioners to have a better understanding of the process performance of the projects and then ensure informed decision-making about actions to be required and taken to improve future performance.

Originality/value

This study contributes to knowledge of performance management by simultaneously addressing the process and stakeholder management theories within the context of PPPs. The proposed PMS provides an insight into managing stakeholders’ influences to enhance the life cycle performance of PPPs.
Constraints and limitations of concrete 3D printing in architecture
Authors: Ko Chien-Ho
Published: June 2021

Purpose

Additive manufacturing of concrete (AMoC) is an emerging technology for constructing buildings. However, due to the nature of the concrete property and constructing buildings in layers, constraints and limitations are encountered while applying AMoC in architecture. This paper aims to analyze the constraints and limitations that may be encountered while using AMoC in architecture.

Design/methodology/approach

A descriptive research approach is used to conduct this study. First, basic notions of AMoC are introduced. Then, challenges of AMoC, including hardware, material property, control and design, are addressed. Finally, strategies that may be used to overcome the challenges are discussed.

Findings

Factors influencing the success of AMoC include hardware, material, control methods, manufacturing process and design. Considering these issues in the early design phase is crucial to achieving a successful computer-aided design (CAD)/computer-aided manufacturing (CAM) integration to bring CAD and CAM benefits into the architecture industry.

Originality/value

In three-dimensional (3D) printing, objects are constructed layer by layer. Printing results are thus affected by the additive method (such as toolpath) and material properties (such as tensile strength and slump). Although previous studies attempt to improve AMoC, most of them focus on the manufacturing process. However, a successful application of AMoC in architecture needs to consider the possible constraints and limitations of concrete 3D printing. So far, research on the potential challenges of applying AMoC in architecture from a building lifecycle perspective is still limited. The study results of this study could be used to improve design and construction while applying AMoC in architecture.