bluuebunny/crossref_metadata_2025 huggingface dataset:
Nuclear dengue virus NS5 antagonizes expression of PAF1-dependent immune response genes
Authors: Petit Marine J. , Kenaston Matthew W. , Nagainis Ariana A. , Shah Priya S.
Published: April 2021

Dengue virus (DENV) disruption of the innate immune response is critical to establish infection. DENV non-structural protein 5 (NS5) plays a central role in this disruption, such as antagonism of STAT2. We recently found that DENV serotype 2 (DENV2) NS5 interacts with Polymerase associated factor 1 complex (PAF1C). The primary members of PAF1C are PAF1, LEO1, CTR9 and CDC73. This nuclear complex is an emerging player in the immune response. It promotes the expression of many genes, including genes related to the antiviral, antimicrobial and inflammatory responses, through close association with the chromatin of these genes. Our previous work demonstrated that NS5 antagonizes PAF1C recruitment to immune response genes. However, it remains unknown if NS5 antagonism of PAF1C is complementary to its antagonism of STAT2. Here, we show that knockout of PAF1 enhances DENV2 infectious virion production. By comparing gene expression profiles in PAF1 and STAT2 knockout cells, we find that PAF1 is necessary to express immune response genes that are STAT2-independent. Finally, we mapped the viral determinants for the NS5-PAF1C protein interaction. We found that NS5 nuclear localization and the C-terminal region of the methyltransferase domain are required for its interaction with PAF1C. Mutation of these regions rescued the expression of PAF1-dependent immune response genes that are antagonized by NS5. In sum, our results support a role for PAF1C in restricting DENV2 replication that NS5 antagonizes through its protein interaction with PAF1C.

Author summary

Dengue virus (DENV) is a pathogen that infects nearly 400 million people a year and thus represents a major challenge for public health. Productive infection by DENV relies on the effective evasion of intrinsic antiviral defenses and is often accomplished through virus-host protein interactions. Here, we investigate the recently discovered interaction between DENV non-structural protein 5 (NS5) and the transcriptional regulator Polymerase associated factor 1 complex (PAF1C). Our work demonstrates PAF1C member PAF1 acts as an antiviral factor and inhibits DENV replication. In parallel, we identified immune response genes involved in intrinsic antiviral defense that depend on PAF1 for expression. We further identified the regions of NS5 required for the protein interaction with PAF1C. Breaking the NS5-PAF1C protein interaction restores the expression of PAF1-dependent immune response genes. Together, our work establishes the antiviral role of PAF1C in DENV infection and NS5 antagonism of PAF1-dependent gene expression through a virus-host protein interaction.
The barley mutantmultiflorus2.breveals quantitative genetic variation for new spikelet architecture
Authors: Koppolu Ravi , Jiang Guojing , Milner Sara G , Muqaddasi Quddoos H , Rutten Twan , Himmelbach Axel , Stein Nils , Mascher Martin , Schnurbusch Thorsten
Published: April 2021

Understanding the genetic basis of yield forming factors in small grain cereals is of extreme importance, especially in the wake of stagnation of further yield gains in these crops. One such yield forming factor in these cereals is the number of grain-bearing florets produced per spikelet. Wildtype barley (Hordeum vulgareL.) spikelets are determinate structures, the spikelet axis (rachilla) degenerates after producing single floret. In contrast, the rachilla of wheat (Triticum ssp.) spikelets, which are indeterminate, elongates to produce up to 12 florets. In our study, we characterized the barley spikelet determinacy mutantmultiflorus2.b(mul2.b) that produced up to three fertile florets on elongated rachillae of lateral spikelets. Apart from the lateral spikelet indeterminacy (LS-IN), we also characterized the supernumerary spikelet phenotype in the central spikelets (CS-SS) ofmul2.b. Through our phenotypic and genetic analyses, we identified two major QTLs on chromosomes 2H and 6H, and two minor QTLs on 3H for the LS-IN phenotype. For, the CS-SS phenotype we identified one major QTL on 6H, and a minor QTL on 5H chromosomes. Notably, the 6H QTLs for CS-SS and LS-IN phenotypes co-located with each other, potentially indicating that a single genetic factor might regulate both phenotypes. Thus, our in-depth phenotyping combined with genetic analyses revealed the quantitative nature of the LS-IN and CS-SS phenotypes inmul2.b, paving the way for cloning the genes underlying these QTLs in the future.

Key message

Spikelet indeterminacy and supernumerary spikelet phenotypes in barleymultiflorus2.bmutant show polygenic inheritance. Genetic analysis ofmultiflorus2.brevealed major QTLs for spikelet determinacy and supernumerary spikelet phenotypes on 2H and 6H chromosomes.
Target identification of drug candidates with machine-learning algorithms: how choosing negative examples for training
Authors: Najm Matthieu , Azencott Chloé-Agathe , Playe Benoit , Stoven Véronique
Published: April 2021

(1) Background:Identification of hit molecules protein targets is essential in the drug discovery process. Target prediction with machine-learning algorithms can help accelerate this search, limiting the number of required experiments. However, Drug-Target Interactions databases used for training present high statistical bias, leading to a high number of false positive predicted targets, thus increasing time and cost of experimental validation campaigns. (2) Methods: To minimize the number of false positive predicted proteins, we propose a new scheme for choosing negative examples, so that each protein and each drug appears an equal number of times in positive and negative examples. We artificially reproduce the process of target identification for 3 particular drugs, and more globally for 200 approved drugs. (3) Results: For the detailed 3 drugs examples, and for the larger set of 200 drugs, training with the proposed scheme for the choice of negative examples improved target prediction results: the average number of false positive among the top ranked predicted targets decreased and overall the rank of the true targets was improved. (4) Conclusion: Our method enables to correct databases statistical bias and reduces the number of false positive predictions, and therefore the number of useless experiments potentially undertaken.
Comprehensive Proteomic Quantification of Bladder Stone Progression in a Cystinuric Mouse Model Using Data-Independent Acquisitions
Authors: Rose Jacob , Basisty Nathan , Zee Tiffany , Wehrfritz Cameron , Bose Neelanjan , Desprez Pierre-Yves , Kapahi Pankaj , Stoller Marshall , Schilling Birgit
Published: April 2021

Cystinuria is one of various disorders that cause biomineralization in the urinary system, including bladder stone formation in humans. It is most prevalent in children and adolescents and more aggressive in males. There is no cure, and only limited disease management techniques help to solubilize the stones. Recurrence, even after treatment, occurs frequently. Other than a buildup of cystine, little is known about factors involved in the formation, expansion, and recurrence of these stones. This study sought to define the growth of bladder stones, guided by micro-computed tomography imaging, and to profile dynamic stone proteome changes in a cystinuria mouse model. After bladder stones developed in vivo, they were harvested and separated into four developmental stages (sand, small, medium and large stone), based on their size. Data-dependent and data-independent acquisitions allowed deep profiling of stone proteomics. The proteomic signatures and pathways illustrated major changes as the stones grew. Stones initiate from a small nidus, grow outward, and show major enrichment in ribosomal proteins and factors related to coagulation and platelet degranulation, suggesting a major dysregulation in specific pathways that can be targeted for new therapeutic options.
Effects of imidacloprid and thiamethoxam at LC30and LC50on the life table of soybean aphidAphis glycines(Hemiptera: Aphididae)
Authors: Zhang Aonan , Zhu Lin , Shi Zhenghao , Zhao Kuijun , Liu Tianying , Han Lanlan
Published: April 2021

The soybean aphid,Aphis glycinesMatsumura (Hemiptera: Aphididae), is a main pests of soybean that poses a serious threat to its production. Studies were conducted to understand effects of the different concentrations of the insecticides (imidacloprid and thiamethoxam) on the life table ofA. glycinesto provide vital information for its effective management. We found that the mean generation time, adult and total pre-oviposition periods inA. glycinesspecimens exposed to LC50imidacloprid and thiamethoxam were significantly longer than those in the control group. However, when exposed to LC30imidacloprid and thiamethoxam, the adult pre-ovipositional period was significantly shorter than that in the control group. The mean fecundity per female adult, net reproductive rate, intrinsic rate of increase, and finite rate of increase were significantly decreased in individuals exposed to LC30and LC50concentrations of imidacloprid and thiamethoxam, respectively (P< 0.05). Both insecticides produce stress effects onA. glycines, and specimens treated with LC50concentrations of the two insecticides exhibited a significant decrease in their growth rates than those treated with LC30concentrations. This study provides data that can be used as a reference to predict the effect of imidacloprid and thiamethoxam on the population dynamics in the field, and agricultural producers could attach importance to prevent stimulation the reproduction made by low-lethal concentrations during actually applying pesticides.
Promoter-sequence determinants and structural basis of primer-dependent transcription initiation inEscherichia coli
Authors: Skalenko Kyle S. , Li Lingting , Zhang Yuanchao , Vvedenskaya Irina O. , Winkelman Jared T. , Cope Alexander , Taylor Deanne M. , Shah Premal , Ebright Richard H. , Kinney Justin B. , Zhang Yu , Nickels Bryce E.
Published: April 2021

Chemical modifications of RNA 5′ ends enable “epitranscriptomic” regulation, influencing multiple aspects of RNA fate. In transcription initiation, a large inventory of substrates compete with nucleoside triphosphates (NTPs) for use as initiating entities, providing anab initiomechanism for altering the RNA 5′ end. InEscherichia colicells, RNAs with a 5′-end hydroxyl are generated by use of dinucleotide RNAs as primers for transcription initiation, “primer-dependent initiation.” Here we use massively systematic transcript end readout (“MASTER”) to detect and quantify RNA 5′ ends generated by primer-dependent initiation for ~410(~1,000,000) promoter sequences inE. coli. The results show primer-dependent initiation inE. coliinvolves any of the 16 possible dinucleotide primers and depends on promoter sequences in, upstream, and downstream of the primer binding site. The results yield a consensus sequence for primer-dependent initiation, YTSS-2NTSS-1NTSSWTSS+1, where TSS is the transcription start site, NTSS-1NTSSis the primer binding site, Y is pyrimidine, and W is A or T. Biochemical and structure-determination studies show that the base pair (nontemplate-strand base:template-strand base) immediately upstream of the primer binding site (Y:RTSS-2, where R is purine) exerts its effect through the base on the DNA template strand (RTSS-2) through inter-chain base stacking with the RNA primer. Results from analysis of a large set of natural, chromosomally-encodedE.colipromoters support the conclusions from MASTER. Our findings provide a mechanistic and structural description of how TSS-region sequence hard-codes not only the TSS position, but also the potential for epitranscriptomic regulation through primer-dependent transcription initiation.
Millisecond Mix-and-Quench Crystallography (MMQX) Enables Time-Resolved Studies of PEPCK With Remote Data Collection
Authors: Clinger Jonathan A. , Moreau David W. , McLeod Matthew J. , Holyoak Todd , Thorne Robert E.
Published: April 2021

Time-resolved crystallography of biomolecules in action has advanced rapidly as methods for serial crystallography have improved, but the large number of crystals and complex experimental infrastructure required remain serious obstacles to widespread application. We have developed Millisecond Mix-and-Quench crystallography (MMQX), which yields millisecond time-resolved data using far fewer crystals and routine remote synchrotron data collection. To demonstrate the capabilities of MMQX, the conversion of oxaloacetic acid to phosphoenolpyruvate by phosphoenolpyruvate carboxykinase is observed with a time resolution of 40 ms. MMQX, by lowering the entry barrier to time-resolved crystallography, should enable broad expansion in structural studies of protein dynamics.
Anuran Heart Metamorphosis: Anatomical Support for Pulmonary Blood Separation in the Early Aquatic Phase
Authors: Kraus Nina , Metscher Brian
Published: April 2021

1.

Background

In both larval and adult anurans, blood separation and respiratory physiology have remained an enigma. While various blood separation mechanisms have been proposed, the same structure is seen as playing a key role: the conus arteriosus. However, previous findings on its internal structure are contradictory, depending on the specifics of the 2D imaging methods used by different authors. To resolve this problem, we used high-resolution X-ray microtomography of wholeBufo bufospecimens to acquire the first detailed 3D descriptions of this complex structure through metamorphosis.

Results

In early tadpoles two small valvular openings develop at the ventricular-conal junction, providing two paths separated by the septum coni and continuing into the aortic arches. Thus, structures to support segregated pulmonary circulation are fully developed well before the lungs appear. The external gills undergo partial resorption and retreat asymmetrically into a gill chamber formed by a hyoidal cover, leaving only a single opening on the left side, the opercular spout.

Conclusions

The timing of events inBufocirculatory development does not track the changing modes of respiration used by the developing tadpole. In particular, a system capable of double circulation carries only oxygen-depleted blood for a significant portion of the tadpole stage.
“Multi-Agent” Screening Improves the Efficiency of Directed Enzyme Evolution
Authors: Yang Tian , Ye Zhixia , Lynch Michael D.
Published: April 2021

Enzyme evolution has enabled numerous advances in biotechnology. However, directed evolution programs can still require many iterative rounds of screening to identify optimal mutant sequences. This is due to the sparsity of the fitness landscape, which in turn, is due to “hidden” mutations that only offer improvements synergistically in combination with other mutations. These “hidden” mutations are only identified by evaluating mutant combinations, necessitating large combinatorial libraries or iterative rounds of screening. Here, we report a multi-agent directed evolution approach that incorporates diverse substrate analogues in the screening process. With multiple substrates acting like multiple agents navigating the fitness landscape, we are able to identify “hidden” mutant residues that impact substrate specificity without a need for testing numerous combinations. We initially validate this approach in engineering a malonyl-CoA synthetase for improved activity with a wide variety of non-natural substrates. We found that “hidden” mutations are often distant from the active site, making them hard to predict using popular structure-based methods. Interestingly, many of the “hidden” mutations identified in this case are expected to destabilize interactions between elements of tertiary structure, potentially affecting protein flexibility. This approach may be widely applicable to accelerate enzyme engineering. Lastly, multi-agent system inspired approaches may be more broadly useful in tackling other complex combinatorial search problems in biology.

Highlights

- “Multi-agent” screening improves directed evolution.

- The incorporation of multiple substrates leads to the identification of “hidden” mutations, which can be hard to identify through one substrate.

- “Hidden” mutations are often remote from the active site and are expected to interrupt stabilizing side-chain interactions, thus increasing enzyme flexibility.
Fast slow folding of an Outer Membrane Porin
Authors: Weatherill Eve E. , Fahie Monifa A. , Marshall David P. , Andvig Rachel A. , Cheetham Matthew R. , Chen Min , Wallace Mark I.
Published: April 2021

In comparison to globular proteins, the spontaneous folding and insertion ofβ-barrel membrane proteins is surprisingly slow, typically occurring on the order of minutes. Using single-molecule Förster Resonance Energy Transfer to report on the folding of fluorescently-labelled Outer Membrane Protein G we measured the real-time insertion of aβ-barrel membrane protein from an unfolded state. Folding events were rare, and fast (<20 ms); occurring immediately upon arrival at the membrane. This combination of infrequent, but rare, folding resolves this apparent dichotomy between slow ensemble kinetics, and the typical timescales of biomolecular folding.
Nuclear RNA-acetylation can be erased by the deacetylase SIRT7
Authors: Kudrin Pavel , Meierhofer David , Vågbø Cathrine Broberg , Ørom Ulf Andersson Vang
Published: April 2021

A large number of RNA modifications are known to affect processing and function of rRNA, tRNA and mRNA1. The N4-acetylcytidine (ac4C) is the only known RNA acetylation event and is known to occur on rRNA, tRNA and mRNA2,3. RNA modification by acetylation affects a number of biological processes, including translation and RNA stability2. For a few RNA methyl modifications, a reversible nature has been demonstrated where specific writer proteins deposit the modification and eraser proteins can remove them by oxidative demethylation4–6. The functionality of RNA modifications is often mediated by interaction with reader proteins that bind dependent on the presence of specific modifications1. The NAT10 acetyltransferase has been firmly identified as the main writer of acetylation of cytidine ribonucleotides, but so far neither readers nor erasers of ac4C have been identified2,3. Here we show, that ac4C is bound by the nucleolar protein NOP58 and deacetylated by SIRT7, for the first time demonstrating reversal by another mechanism than oxidative demethylation. NOP58 and SIRT7 are involved in snoRNA function and pre-ribosomal RNA processing7–10, and using a NAT10 deficient cell line we can show that the reduction in ac4C levels affects both snoRNA sub-nuclear localization and pre-rRNA processing. SIRT7 can deacetylate RNAin vitroand endogenous levels of ac4C on snoRNA increase in a SIRT7 deficient cell line, supporting its endogenous function as an RNA deacetylase. In summary, we identify the first eraser and reader proteins of the RNA modification ac4C, respectively, and suggest an involvement of RNA acetylation in snoRNA function and pre-rRNA processing.
Morphology of migration: Associations between wing, and bill morphology and migration in kingbirds (Tyrannus)
Authors: MacPherson Maggie P. , Jahn Alex E. , Mason Nicholas A.
Published: April 2021

Morphology is closely linked to locomotion and diet in animals. In animals that undertake long-distance migrations, limb-morphology is under selection to maximize mobility and minimize energy expenditure. Migratory behaviors also interact with diet, such that migratory animals tend to be dietary generalists, while sedentary taxa tend to be dietary specialists. Despite a hypothesized link between migration status and morphology, phylogenetic comparative studies have yielded conflicting findings. We tested for evolutionary associations between migratory status and limb and bill morphology across kingbirds, a pan-American genus of birds with migratory, partially migratory, and sedentary taxa. Migratory kingbirds had longer wings, in agreement with expectations if selection favors improved aerodynamics for long-distance migration. We also found an association between migratory status and bill shape, such that more migratory taxa had wider, deeper, and shorter bills compared to sedentary taxa. However, there was no difference in intraspecific morphological variation among migrants, partial migrants, and residents, suggesting that dietary specialization has evolved independently of migration strategy. The evolutionary links between migration, diet, and morphology in kingbirds uncovered here further strengthen ecomorphological associations that underlie long-distance seasonal movements in animals.
Potassium channel-driven bioelectric signaling regulates metastasis in triple-negative breast cancer
Authors: Payne Samantha L , Ram Priyanka , Srinivasan Deepti H. , Le Thanh T. , Levin Michael , Oudin Madeleine J
Published: April 2021

There is a critical need to better understand the mechanisms that drive local cell invasion and metastasis to develop new therapeutics targeting metastatic disease. Bioelectricity is an important mediator of cellular processes and changes in the resting membrane potential (RMP) are associated with increased cancer cell invasion. However, the mechanism is not well understood. Our data demonstrate that altering the RMP of triple-negative breast cancer (TNBC) cells by manipulating potassium channel expression increasesin vitroinvasion,in vivotumor growth, and metastasis, and is accompanied by changes in gene expression associated with cell adhesion. We describe a novel mechanism for RMP-mediated cell migration involving cadherin-11 and the MAPK pathway. Importantly, we identify a new strategy to target metastatic TNBCin vivoby repurposing FDA-approved potassium channel blockers. Our results provide an understanding of the mechanisms by which bioelectricity regulates cancer cell invasion and metastasis that could lead to a new class of therapeutics for patients with metastatic disease.
Intron Losses and Gains in Nematodes: Not Eccentric at All
Authors: Ma Ming-Yue , Xia Ji , Shu Kunxian , Niu Deng-Ke
Published: April 2021

The evolution of spliceosomal introns has been widely studied among various eukaryotic groups. Researchers nearly reached the consensuses on the pattern and the mechanisms of intron losses and gains across eukaryotes. However, according to previous studies that analyzed a few genes or genomes of nematodes, Nematoda seem to be an eccentric group. Taking advantage of the recent accumulation of sequenced genomes, we carried out an extensive analysis on the intron losses and gains using 104 nematodes genomes across all the five Clades of the phylum. Nematodes have a wide range of intron density, from less than one to more than nine per 1kbp coding sequence. The rates of intron losses and gains exhibit significant heterogeneity both across different nematode lineages and across different evolutionary stages of the same lineage. The frequency of intron losses far exceeds that of intron gains. Five pieces of evidence supporting the model of cDNA-mediated intron loss have been observed in tenCaenorhabditisspecies, the dominance of the precise intron losses, frequent loss of adjacent introns, and high-level expression of the intron-lost genes, preferential losses of short introns, and the preferential losses of introns close to 3′-ends of genes. Like studies in most eukaryotic groups, we cannot find the source sequences for the limited number of intron gains detected in theCaenorhabditisgenomes. All the results indicate that nematodes are a typical eukaryotic group rather than an outlier in intron evolution.
delilah, prosperoandD-Pax2constitute a gene regulatory network essential for the development of functional proprioceptors
Authors: Avetisyan Adel , Glatt Yael , Cohen Maya , Timerman Yael , Aspis Nitay , Nachman Atalya , Halachmi Naomi , Noon Ella Preger-Ben , Salzberg Adi
Published: April 2021

Coordinated animal locomotion depends on the development of functional proprioceptors. While early cell-fate determination processes are well characterized, little is known about the terminal differentiation of cells within the proprioceptive lineage and the genetic networks that control them. In this work we describe a gene regulatory network consisting of three transcription factors-Prospero (Pros), D-Pax2 and Delilah (Dei)-that dictates two alternative differentiation programs within the proprioceptive lineage in Drosophila. We show that D-Pax2 and Pros control the differentiation of cap versus scolopale cells in the chordotonal organ lineage by, respectively, activating and repressing the transcription ofdei.Normally, D-Pax2 activates the expression ofdeiin the cap cell but is unable to do so in the scolopale cell where Pros is co-expressed. We further show that D-Pax2 and Pros exert their effects ondeitranscription via a 262 bp chordotonal-specific enhancer in which two D-Pax2- and three Pros-binding sites were identified experimentally. When this enhancer was removed from the fly genome, the cap- and ligament-specific expression ofdeiwas lost, resulting in loss of chordotonal organ functionality and defective larval locomotion. Thus, coordinated larval locomotion depends on the activity of adeienhancer that integrates both activating and repressive inputs for the generation of a functional proprioceptive organ.
Quadrotor navigation in dynamic environments with deep reinforcement learning
Authors: Fang Jinbao , Sun Qiyu , Chen Yukun , Tang Yang
Published: April 2021

Purpose

This work aims to combine the cloud robotics technologies with deep reinforcement learning to build a distributed training architecture and accelerate the learning procedure of autonomous systems. Especially, a distributed training architecture for navigating unmanned aerial vehicles (UAVs) in complicated dynamic environments is proposed.

Design/methodology/approach

This study proposes a distributed training architecture named experience-sharing learner-worker (ESLW) for deep reinforcement learning to navigate UAVs in dynamic environments, which is inspired by cloud-based techniques. With the ESLW architecture, multiple worker nodes operating in different environments can generate training data in parallel, and then the learner node trains a policy through the training data collected by the worker nodes. Besides, this study proposes an extended experience replay (EER) strategy to ensure the method can be applied to experience sequences to improve training efficiency. To learn more about dynamic environments, convolutional long short-term memory (ConvLSTM) modules are adopted to extract spatiotemporal information from training sequences.

Findings

Experimental results demonstrate that the ESLW architecture and the EER strategy accelerate the convergence speed and the ConvLSTM modules specialize in extract sequential information when navigating UAVs in dynamic environments.

Originality/value

Inspired by the cloud robotics technologies, this study proposes a distributed ESLW architecture for navigating UAVs in dynamic environments. Besides, the EER strategy is proposed to speed up training processes of experience sequences, and the ConvLSTM modules are added to networks to make full use of the sequential experiences.
Unripe Cavendish banana (Musa acuminata) and enzymatic hydrolysis (Flavourzyme®) enhance sensorial and nutritional profiles of functional chicken nugget
Authors: Teo Corine Sze Xuan , Yan See Wan
Published: April 2021

Purpose

Health promotion and disease prevention by means of functional foods have become more popular among consumers due to the rising trend of non-communicable diseases. Driven by the increased demand, the authors aimed to investigate sensorial, nutritional and physicochemical properties of chicken nugget incorporated with unripe Cavendish banana and Flavourzyme® [Control (without banana and Flavourzyme®), F1 (banana only), F2 (Flavourzyme® only), F3 (banana and Flavourzyme®)].

Design/methodology/approach

Sensory evaluation was carried out by means of 9-point hedonic scale among consumer panels (n = 83) to evaluate control, F1, F2 and F3. These were then subjected to chemical (moisture, protein, fat, ash, carbohydrate, total dietary fibre, potassium and antioxidant contents) and physical (texture profile and water activity) analyses.

Findings

Sensory acceptance of control was significantly higher compared to other formulations. Fibre, antioxidant and potassium contents were significantly higher, although moisture, protein and fat contents were significantly lower in F1 and F3 compared to control. Remarkably, F1 and F3 were eligible to be declared as “source of dietary fibre”. Therefore, F1, F2 and F3 can serve as healthier alternatives with high antioxidant activity without compromising consumers' acceptance.

Originality/value

This innovative study generates unique findings pertaining to the nutritional values of novel functional chicken nugget and the formulation enables it to be declared as a source of dietary fibre. Results have contributed knowledge to existing literature as well as benefits food manufacturers in creating healthy functional food to better meet the needs and expectations of health-conscious consumers, healthcare providers, governmental organisations and consumer advocacy groups.
Internal environmental management and green human resource management: significant catalysts for improved corporate reputation and performance
Authors: Afum Ebenezer , Agyabeng-Mensah Yaw , Opoku Mensah Abigail , Mensah-Williams Enoch , Baah Charles , Dacosta Essel
Published: April 2021

Purpose

This paper investigates the combined effect of internal environmental management (IEM) and green human resource management (GHRM) on corporate reputation (CR), environmental performance (EP) and financial performance (FP). The paper further explores the indirect effects of CR and EP between the direct paths.

Design/methodology/approach

Data are garnered from 164 firms from three industries in Ghana. Partial least square structural equation modeling (PLS-SEM) is the methodological technique used to test the hypothesized relationships.

Findings

The result demonstrates that unlike IEM which has a significant effect on FP when implemented in isolation, GHRM does not have a significant effect on FP. However, the joint implementation of IEM and GHRM can provide better results in terms of improved CR, enhanced EP and significant FP improvement. CR and EP were further found to mediate the relationship between the direct paths.

Practical implications

The results suggest that the joint implementation of IEM and GHRM is critical for firms that seek to enjoy superior reputation, enhance their environmental sustainability and achieve financial gains. Consequently, managers are strongly encouraged to create a sustainable and vibrant company via significant and rational investment in green initiatives like IEM and GHRM.

Originality/value

This study happens to be one of the first to develop a research model that investigates the joint effect of IEM and GHRM within the context of CR, environmental sustainability and FP.
Corporate liquidity, supply chain and cost issues awareness within the Covid-19 context: evidence from us management reports’ textual analysis
Authors: Fassas Athanasios , Bellos Sotirios , Kladakis George
Published: April 2021

Purpose

The purpose of this study is to assess the management responses and intentions of 3,279 US firms from all industries, before and after the coronavirus outbreak, to identify the level of managerial concern about specific financial issues and potential economic costs of the COVID-19 pandemic.

Design/methodology/approach

This paper uses textual analysis of official management reports to search for specific single words in five domains related to corporate finance and governance. This paper focuses on the relative frequency of single words using a weighting scheme that adjusts for document length and for the inverse document frequency. This paper then uses t-tests to investigate the univariate differences across groups of reports before and after the US stock market crash in February 2020.

Findings

The applied textual and empirical analysis provides evidence that firms’ primary concerns relate to the disruption in supply chains, liquidity need and coronavirus-led recession. This paper also shows that the main cost reduction measure they are considering is salary reduction, rather than workforce reduction. This paper also shows evidence that firm managers are rather swift to provide coronavirus-related information in the US Securities and Exchange Commission (SEC) corporate filings.

Practical implications

The findings provide a primary view of the directions, on which US firms will move in the near future, and thus, they can be used as tools for the formulation of appropriate government policies in the corresponding sectors, which could mitigate the economic risks related to the pandemic. At the business level, the disseminated knowledge can assist firms either in the same sector or in similar/related sectors to “locate” themselves within the map of the pandemic and to adjust or align correspondingly their strategies and decisions as they will have a view of the bigger picture.

Originality/value

The empirical analysis divulges US firms’ management primary concerns after the COVID-19 outbreak, and thus, offers insights to the processes taking place in the US business community and the formulating new corporate and economic reality.
Revisiting the effects of anthropomorphism on brand relationship outcomes: the moderating role of psychological disposition
Authors: Chen Kuan-Ju , Lin Jhih-Syuan
Published: April 2021

Purpose

Given the thriving attention paid to brand personification in marketing, this paper aims to delve into consumers’ psychological traits that may moderate the positive anthropomorphic effects on brand outcomes specific to relationship marketing.

Design/methodology/approach

A theoretical model was proposed based on a review of the extant literature. Study 1 conducted an online survey and used confirmatory factor analysis to validate the constructs significantly correlated with anthropomorphic processing. Two follow-up studies (Study 2a and 2b) using experimental designs were performed to provide evidence substantiating the moderated mediation in the process.

Findings

Based on the results across the three studies, motivational, rather than cognitive, disposition significantly correlates with perceived anthropomorphism and brand relationship outcomes. Need for belonging serves as a sociality moderator in strengthening the mediating effects of perceived anthropomorphism on brand attachment and brand experience, respectively. Parasocial interaction serves as an effectance moderator in augmenting the mediating effects of perceived anthropomorphism on brand attachment.

Research limitations/implications

This research extends and contrasts the theoretical grounding for anthropomorphism as a set of situational consumer perceptions by integrating its boosting factors in social psychology with emerging brand constructs in marketing and consumer behavior research. More studies are encouraged to probe into the complex anthropomorphic phenomenon.

Practical implications

This research sheds light on marketers’ strategic management efforts in implementing brand personification to target a wide range of market segments with diverse psychological disposition.

Originality/value

Conceiving anthropomorphism as an in-process situational output in information processing, this research provides further understanding of the psychological traits that facilitate the construction of consumer-brand relationships through anthropomorphic perceptions in the context of brand personification.
Board gender diversity: performance and risk of Brazilian firms
Authors: Mastella Mauro , Vancin Daniel , Perlin Marcelo , Kirch Guilherme
Published: April 2021

Purpose

This study aims to intend to check if female board representation affects performance and risk and to analyse the evolution of the demographic aspects of the presence of women on boards in Brazil.

Design/methodology/approach

The authors used a sample of 150 Brazilian publicly traded companies from 2010–2018, with different measures of firm performance, firm risk and women’s presence on the board. The study approach is based on a set of ordinary least squares, quantile and panel data regressions.

Findings

The presence of women on the board has a positive effect on all of our accounting and market performance measures. However, the result of the impact on risk is not conclusive. The study also found that the number of females on the board has a more significant effect at the lower levels of firm performance measured by return on equity, but at the higher levels when measured by Tobin’s Q. Regarding return on assets, the more significant effect happened on the extremes of the performance distribution. The study findings point that market investors place more value in female presence on the board than in director positions.

Originality/value

By estimating the impact of women’s presence on the boards of directors in firm performance and risk, this study aimed to verify this impact in different aspects of the company. In addition, the authors did so in a sample with many years, making it possible to evaluate the historical evolution of the feminine presence in the boards of administration as well as in the groups of directors, assisting Brazilian legislators with new evidence about the possible impacts of Draft Law 7179/2017.
Why do hotels find reducing their carbon footprint difficult?
Authors: Chan Eric S.W.
Published: April 2021

Purpose

The term “carbon footprint” emerged during the early 2000s, but many hotels remain unaware of what they should do to implement a comprehensive programme to reduce carbon footprint despite having some environmental measures. This study aims to investigate the barriers to reducing hotel carbon footprint and to explore why many hotel managers remain bystanders.

Design/methodology/approach

In-depth semi-structured interviews were conducted with hotel executives to understand what hinders hotels’ implementation of comprehensive programmes to reduce their carbon footprint. The NVivo 11 software package was used to organise data and code the transcribed interviews to identify patterns and themes.

Findings

The findings identified several main barriers. They were (1) a lack of understanding, (2) a lack of owner initiative, (3) difficulty with measurements, (4) a lack of stakeholder coordination and support, (5) a lack of a strong mediator, (6) balancing interests and (7) risky investment. The findings of this study suggest some specific strategies for overcoming these barriers.

Research limitations/implications

The study sample was restricted to the Hong Kong hotel executives interviewed; therefore, the findings will not reflect the full picture of managerial perceptions. Drawing on the foundations laid by this study, researchers could collect quantitative data from hotels in other countries to conduct a cross-cultural study.

Originality/value

Very few studies have investigated barriers to carbon-footprint reduction programmes. Specifically, none have been published in the hotel environmental management literature. This study represents a preliminary step towards understanding the barriers that prevent hotels from implementing the programmes.
Influence of microdimple on lubrication performance of textured plunger pump
Authors: Jia Hekun , Zhou Zeyuan , Yin Bifeng , Zhou Huiqin , Xu Bo
Published: April 2021

Purpose

The purpose of this study is to investigate the influence of dimple radius, depth and density on the lubrication performance of the plunger.

Design/methodology/approach

A lubrication model was adopted to consider eccentricity and deformation during the working process of the plunger, and a rig test was performed to confirm the simulation results. The texture was fabricated using laser surface texturing.

Findings

The simulation results suggested that when dimple radius or depth increases, oil film thickness of the plunger increases before decreasing, and asperity friction displays an opposite trend. Therefore, appropriate microdimple texture could facilitate lubrication performance improvement and reduce the wear. Microdimples were then lased on the plunger surface, and a basic tribological test was conducted to validate the simulation results. The experimental results suggested that the average friction coefficient decreased from 0.18 to 0.13, a reduction of 27.8%.

Social implications

The introduction of microdimple on a plunger couple to reduce friction and improve lubrication is expected to provide a new approach to developing high-performance plunger couple and improve the performance of the internal combustion engine. If applied, the surface texture could help reduce friction by around 27% and cap the cost relative to the plugger friction.

Originality/value

The microdimple texture was introduced into the plunger couple of a vehicle to reduce the friction and improve the performance. Findings suggested that surface texture could be used in the automotive industry to improve oil efficiency and lubrication performance.

Peer review

The peer review history for this article is available at: http://dx.doi.org/10.1108/ILT-07-2020-0259.
Enhanced disturbance observer-based robust yaw servo control for ROVs with multi-vector propulsion
Authors: Gong Yihui , Li Lin , Qi Shengbo , Wang Changbin , Song Dalei
Published: April 2021

Purpose

A novel proportional integral derivative-extended state disturbance observer-based control (PID-ESDOBC) algorithm is proposed to solve the nonlinear hydrodynamics, parameters perturbation and external disturbance in yaw control of remote operated vehicles (ROVs). The effectiveness of PID-ESDOBC is verified through the experiments and the results indicate that the proposed method can effectively track the desired attitude and attenuate the external disturbance.

Design/methodology/approach

This study fully investigates the hydrodynamic model of ROVs and proposes a control-oriented hydrodynamic state space model of ROVs in yaw direction. Based on this, this study designs the PID-ESDOBC controller, whose stability is also analyzed through Kharitonov theorem and Mikhailov criterion. The conventional proportional-integral-derivative (PID) and active disturbance rejection control (ADRC) are compared with our method in our experiment.

Findings

In this paper, the authors address the nonlinear hydrodynamics, parameters perturbation and external disturbance problems of ROVs with multi-vector propulsion by using PID-ESDOBC control scheme. The advantage is that the nonlinearities and external disturbance can be estimated accurately and attenuate promptly without requiring the precise model of ROVs. Compared to PID and ADRC, both in overshoot and settling time, the improvement is 2X on average compared to conventional PID and ADRC in the pool experiment.

Research limitations/implications

The delays occurred in the control process can be solved in the future work.

Practical implications

The attitude control is a kernel problem for ROVs. A precise kinematic and dynamic model for ROVs and an advanced control system are the key factors to obtain the better maneuverability in attitude control. The PID-ESDOBC method proposed in this paper can effectively attenuate nonlinearities and external disturbance, which leads to a quick response and good tracking performance to baseline controller.

Social implications

The PID-ESDOBC algorithm proposed in this paper can be ensure the precise and fast maneuverability in attitude control of ROVs or other underwater equipment operating in the complex underwater environment. In this way, the robot can better perform undersea work and tasks.

Originality/value

The dynamics of the ROV and the nominal control model are investigated. A novel control scheme PID-ESDOBC is proposed to achieve rapidly yaw attitude tracking and effectively reject the external disturbance. The robustness of the controller is also analyzed which provides parameters tuning guidelines. The effectiveness of the proposed controller is experimental verified with a comparison by conventional PID, ADRC.
Topological drone navigation in uncertain environment
Authors: Patle Bhumeshwar , Chen Shyh-Leh , Patel Brijesh , Kashyap Sunil Kumar , Sanap Sudarshan
Published: April 2021

Purpose

With the increasing demand for surveillance and smart transportation, drone technology has become the center of attraction for robotics researchers. This study aims to introduce a new path planning approach to drone navigation based on topology in an uncertain environment. The main objective of this study is to use the Ricci flow evolution equation of metric and curvature tensor over angular Riemannian metric, and manifold for achieving navigational goals such as path length optimization at the minimum required time, collision-free obstacle avoidance in static and dynamic environments and reaching to the static and dynamic goals. The proposed navigational controller performs linearly and nonlinearly both with reduced error-based objective function by Riemannian metric and scalar curvature, respectively.

Design/methodology/approach

Topology and manifolds application-based methodology establishes the resultant drone. The trajectory planning and its optimization are controlled by the system of evolution equation over Ricci flow entropy. The navigation follows the Riemannian metric-based optimal path with an angular trajectory in the range from 0° to 360°. The obstacle avoidance in static and dynamic environments is controlled by the metric tensor and curvature tensor, respectively. The in-house drone is developed and coded using C++. For comparison of the real-time results and simulation results in static and dynamic environments, the simulation study has been conducted using MATLAB software. The proposed controller follows the topological programming constituted with manifold-based objective function and Riemannian metric, and scalar curvature-based constraints for linear and nonlinear navigation, respectively.

Findings

This proposed study demonstrates the possibility to develop the new topology-based efficient path planning approach for navigation of drone and provides a unique way to develop an innovative system having characteristics of static and dynamic obstacle avoidance and moving goal chasing in an uncertain environment. From the results obtained in the simulation and real-time environments, satisfactory agreements have been seen in terms of navigational parameters with the minimum error that justifies the significant working of the proposed controller. Additionally, the comparison of the proposed navigational controller with the other artificial intelligent controllers reveals performance improvement.

Originality/value

In this study, a new topological controller has been proposed for drone navigation. The topological drone navigation comprises the effective speed control and collision-free decisions corresponding to the Ricci flow equation and Ricci curvature over the Riemannian metric, respectively.