bluuebunny/crossref_metadata_2025 huggingface dataset:
Heritable variation and lack of tradeoffs suggest adaptive capacity inAcropora cervicornisdespite negative synergism under climate change scenarios
Authors: Muller Erinn M. , Dungan Ashley M. , Million Wyatt C. , Eaton Katherine R. , Petrik Chelsea , Bartels Erich , Hall Emily R. , Kenkel Carly D.
Published: October 2021

Knowledge of multi-stressor interactions and the potential for tradeoffs among tolerance traits is essential for developing intervention strategies for the conservation and restoration of reef ecosystems in a changing climate. Thermal extremes and acidification are two major co-occurring stresses predicted to limit the recovery of vital Caribbean reef-building corals. Here, we conducted an aquarium-based experiment to quantify the effects of increased water temperatures andpCO2individually and in concert on 12 genotypes of the endangered branching coralAcropora cervicornis,currently being reared and outplanted for large-scale coral restoration. Quantification of 12 host, symbiont and holobiont traits throughout the two-month-long experiment showed several synergistic negative effects, where the combined stress treatment often caused a greater reduction in physiological function than the individual stressors alone. However, we found significant genetic variation for most traits and positive trait correlations among treatments indicating an apparent lack of tradeoffs, suggesting that adaptive evolution will not be constrained. Our results suggest that it may be possible to incorporate climate-resistant coral genotypes into restoration and selective breeding programmes, potentially accelerating adaptation.
Mass-flowering monoculture attracts bees, amplifying parasite prevalence
Authors: Cohen Hamutahl , Smith Gordon P. , Sardiñas Hillary , Zorn Jocelyn F. , McFrederick Quinn S. , Woodard S. Hollis , Ponisio Lauren C.
Published: October 2021

As the global agricultural footprint expands, it is increasingly important to address the link between the resource pulses characteristic of monoculture farming and wildlife epidemiology. To understand how mass-flowering crops impact host communities and subsequently amplify or dilute parasitism, we surveyed wild and managed bees in a monoculture landscape with varying degrees of floral diversification. We screened 1509 bees from 16 genera in sunflower fields and in non-crop flowering habitat across 200 km
2
of the California Central Valley. We found that mass-flowering crops increase bee abundance. Wild bee abundance was subsequently associated with higher parasite presence, but only in sites with a low abundance of non-crop flowers. Bee traits related to higher dispersal ability (body size) and diet breadth (pollen lecty) were also positively related to parasite presence. Our results highlight the importance of non-crop flowering habitat for supporting bee communities. We suggest monoculture alone cannot support healthy bees.
Introduction of probiotic bacterial consortia promotes plant growth via impacts on the resident rhizosphere microbiome
Authors: Hu Jie , Yang Tianjie , Friman Ville-Petri , Kowalchuk George A. , Hautier Yann , Li Mei , Wei Zhong , Xu Yangchun , Shen Qirong , Jousset Alexandre
Published: October 2021

Plant growth depends on a range of functions provided by their associated rhizosphere microbiome, including nutrient mineralization, hormone co-regulation and pathogen suppression. Improving the ability of plant-associated microbiomes to deliver these functions is thus important for developing robust and sustainable crop production. However, it is yet unclear how beneficial effects of probiotic microbial inoculants can be optimized and how their effects are mediated. Here, we sought to enhance tomato plant growth by targeted introduction of probiotic bacterial consortia consisting of up to eight plant-associated
Pseudomonas
strains. We found that the effect of probiotic consortium inoculation was richness-dependent: consortia that contained more
Pseudomonas
strains reached higher densities in the tomato rhizosphere and had clearer beneficial effects on multiple plant growth characteristics. Crucially, these effects were best explained by changes in the resident community diversity, composition and increase in the relative abundance of initially rare taxa, instead of introduction of plant-beneficial traits into the existing community along with probiotic consortia. Together, our results suggest that beneficial effects of microbial introductions can be driven indirectly through effects on the diversity and composition of the resident plant rhizosphere microbiome.
Cross-modal individual recognition in the African penguin and the effect of partnership
Authors: Baciadonna Luigi , Solvi Cwyn , La Cava Sara , Pilenga Cristina , Gamba Marco , Favaro Livio
Published: October 2021

An animal's ability to recognize another individual by matching their image to their voice suggests they form internal representations of other individuals. To what extent this ability, termed cross-modal individual recognition, extends to birds other than corvids is unknown. Here, we used an expectancy violation paradigm to determine whether a monogamous territorial seabird (Spheniscus demersus) can cross-modally recognize familiar conspecifics (partners or colony-mates). After pairs of penguins spent time together in an isolated area, one of the penguins was released from the area leaving the focal penguin alone. Subsequently, we played contact calls of the released penguin (congruent condition) or a different penguin (incongruent condition). After being paired with a colony-mate, focal penguins' response latency to the auditory stimulus was faster in the incongruent compared to congruent condition, indicating the mismatch violated their expectations. This behavioural pattern was not observed in focal penguins after being paired with their partner. We discuss these different results in the light of penguins’ natural behaviour and the evolution of social communication strategies. Our results suggest that cross-modal individual recognition extends to penguins and reveals, in contrast with previously thought, that social communication between members of this endangered species can also use visual cues.
Integrating genomics and multivariate evolutionary quantitative genetics: a case study of constraints on sexual selection in
Drosophila serrata
Authors: Reddiex Adam J. , Chenoweth Stephen F.
Published: October 2021

In evolutionary quantitative genetics, the genetic variance–covariance matrix,
G
, and the vector of directional selection gradients,

β

, are key parameters for predicting multivariate selection responses and genetic constraints. Historically, investigations of
G
and

β

have not overlapped with those dissecting the genetic basis of quantitative traits. Thus, it remains unknown whether these parameters reflect pleiotropic effects at individual loci. Here, we integrate multivariate genome-wide association study (GWAS) with
G
and

β

estimation in a well-studied system of multivariate constraint: sexual selection on male cuticular hydrocarbons (CHCs) in
Drosophila serrata
. In a panel of wild-derived re-sequenced lines, we augment genome-based restricted maximum likelihood to estimate
G
alongside multivariate single nucleotide polymorphism (SNP) effects, detecting 532 significant associations from 1 652 276 SNPs. Constraint was evident, with

β

lying in a direction of
G
with low evolvability. Interestingly, minor frequency alleles typically increased male CHC-attractiveness suggesting opposing natural selection on

β

. SNP effects were significantly misaligned with the major eigenvector of
G
,

g

max
, but well aligned to the second and third eigenvectors

g

2
and

g

3
. We discuss potential factors leading to these varied results including multivariate stabilizing selection and mutational bias. Our framework may be useful as researchers increasingly access genomic methods to study multivariate selection responses in wild populations.
Time-based binding as a solution to and a limitation for flexible cognition
Authors: Senoussi Mehdi , Verbeke Pieter , Verguts Tom
Published: October 2021

Why can’t we keep as many items as we want in working memory? It has long been debated whether this resource limitation is a bug (a downside of our fallible biological system) or instead a feature (an optimal response to a computational problem). We propose that the resource limitation is a consequence of a useful feature. Specifically, we propose that flexible cognition requires time-based binding, and time-based binding necessarily limits the number of (bound) memoranda that can be stored simultaneously. Time-based binding is most naturally instantiated via neural oscillations, for which there exists ample experimental evidence. We report simulations that illustrate this theory and that relate it to empirical data. We also compare the theory to several other (feature and bug) resource theories.
Environmentally dependent and independent control of cell shape determination by Rho GTPase regulators in melanoma
Authors: Dent L. G. , Curry N. , Sparks H. , Bousgouni V. , Maioli V. , Kumar S. , Munro I. , Dunsby C. , Bakal C.
Published: October 2021

In order to invade 3D tissues, cancer cells dynamically change cell morphology in response to geometric and mechanical cues in the environment. But how cells determine their shape in 3D versus 2D environments is poorly understood. Studying 2D versus 3D single cell shape determination has historically been technically difficult due to the lack of methodologies to directly compare the two environments. We developed an approach to study cell shape in 2D versus 3D by measuring cell shape at different depths in collagen using stage-scanning oblique plane microscopy (ssOPM). We find characteristic shape changes occur in melanoma cells depending on whether a cell is attached to a 2D surface or 3D environment, and that these changes can be modulated by Rho GTPase regulatory proteins. Our data suggest that regulation of cell protrusivity undergoes a ‘switch’ of control between different Rho GTPase regulators depending on the physical microenvironment.
A functionally conserved STORR gene fusion in Papaver species that diverged 16.8 million years ago
Authors: Catania Theresa , Li Yi , Winzer Thilo , Harvey David , Meade Fergus , Caridi Anna , Larson Tony R. , Ning Zemin , Graham Ian A
Published: October 2021

The STORR gene fusion event is considered a key step in the evolution of benzylisoquinoline alkaloid (BIA) metabolism in opium poppy as the resulting bi-modular protein performs the isomerization of (S)- to (R)-reticuline which is required for morphinan biosynthesis. Our previous analysis of the opium poppy genome suggested the STORR gene fusion event occurred before a whole genome duplication event 7.2 million years ago. Here we use a combination of phylogenetic, transcriptomic, metabolomic, biochemical and genomic analysis to investigate the origin of the STORR gene fusion across the Papaveraceae family. The pro-morphinan/morphinan subclass of BIAs was present in a subset of 10 Papaver species including P. somniferum (opium poppy) and this correlated with the presence of the STORR gene fusion with one important exception. P. californicum does not produce morphinans but it does contain a STORR gene fusion that epimerizes (S)- to (R)-reticuline when heterologously expressed in yeast. The high similarity of the amino acid sequence linking the two modules of STORR along with phylogenetic gene tree analysis strongly suggests the gene fusion occurred only once and between 17-25 million years ago before the separation of P. californicum from the other Papaver species. We discovered that the most abundant BIA in P. californicum is (R)-glaucine, a member of the aporphine subclass of BIAs. Only the (S) isomer of this compound has previously been reported from nature. These results lead us to conclude that the function of the STORR gene fusion is not exclusive to morphinan production in the Papaveraceae.
Coincident Fluorescence Burst Analysis of dUTP-Loaded Exosome-Mimetic Nanovesicles
Authors: Sanaee Maryam , Sandberg Elin , Ronquist K. Göran , Morrell Jane M. , Widengren Jerker , Gallo Katia
Published: October 2021

The targeting functionality and low immunogenicity of exosomes and exosome-mimetic nanovesicles make them promising as drug-delivery carriers. To tap into this potential, accurate non-destructive methods to load them and characterize their contents are of utmost importance. However, their small size, polydispersity and aggregation in solution make quantitative characterizations of their loading particularly challenging. Here we develop an ad-hoc methodology based on a burst analysis of dual-color confocal fluorescence microscopy experiments, suited for quantitative characterizations of exosome-like nanovesicles and of their loading. We apply it to study bioengineered nanovesicles, loaded with dUTP cargo molecules, synthetized from detergent-resistant membranes of animal extracellular vesicles and human red blood cells. For both classes of bioengineered nanovesicles we prove, by means of dual-color fluorescence cross-correlation spectroscopy (FCCS), successful loading. Furthermore, by a dual-color coincident fluorescence burst (DC-CFB) analysis of the experimental data, we retrieve size and loading statistics for both types of nanovesicles. The procedure affords single-vesicle characterizations, which are essential for reliable quantitative studies of loading processes in exosomes and exosome-mimetic nanovesicles, especially in light of the typically high heterogeneity of their populations. Moreover, the method implementation can be easily adapted to the investigation of a variety of combinations of different cargo molecules and biological nanovesicles besides the proof-of-principle demonstrations considered in this study. The results provide a powerful characterization tool, well-suited for the optimization of loading processes of biomimetic nanovesicles and their advanced engineering for therapeutic drug delivery.
Application of synthetic peptide CEP1 increases nutrient uptake rates along plant roots
Authors: Roy Sonali , Griffiths Marcus , Torres-Jerez Ivone , Sanchez Bailey , Antonelli Elizabeth , Jain Divya , Krom Nicholas , Zhang Shulan , York Larry M. , Scheible Wolf-Rüdiger , Udvardi Michael K.
Published: October 2021

The root system of a plant provides vital functions including resource uptake, storage, and anchorage in soil. Uptake from the soil of macro-nutrients like nitrogen (N), phosphorus (P), potassium (K), and sulphur (S) is critical for plant growth and development. Small signaling peptide (SSP) hormones are best known as potent regulators of plant growth and development with a few also known to have specialized roles in macronutrient utilization. Here we describe a high-throughput screen of SSP effects on root uptake of multiple nutrients. The SSP, MtCEP1 enhanced nitrate uptake rate per unit root length in Medicago truncatula plants deprived of N. MtCEP1 and AtCEP1 enhanced uptake not only of nitrate, but also phosphate and sulfate in both Medicago and Arabidopsis. Transcriptome analysis of Medicago roots treated with different MtCEP1 encoded peptide domains revealed that hundreds of genes respond to these peptides, including several nitrate transporters and a sulfate transporter that may mediate the uptake of these macronutrients downstream of CEP1 signaling. Likewise, several putative signaling pathway genes were induced in roots by CEP1 treatment. Thus, a scalable method has been developed for screening synthetic peptides of potential use in agriculture, with CEP1 shown to be one such peptide.
Sparse Representation Learning Derives Biological Features with Explicit Gene Weights from the Allen Mouse Brain Atlas
Authors: Abbasi Mohammad , Sanderford Connor R , Raghu Narendiran , Pasha Mirjeta , Bartelle Benjamin B
Published: October 2021

Unsupervised learning methods are commonly used to detect features within transcriptomic data and ultimately derive meaningful representations of biology. Contributions of individual genes to any feature however becomes convolved with each learning step, requiring followup analysis and validation to understand what biology might be represented by a cluster on a low dimensional plot. We sought learning methods that could preserve the gene information of detected features, using the spatial transcriptomic data and anatomical labels of the Allen Mouse Brain Atlas as a test dataset with verifiable ground truth. We established metrics for accurate representation of molecular anatomy to find sparse learning approaches were uniquely capable of generating anatomical representations and gene weights in a single learning step. Fit to labeled anatomy was highly correlated with intrinsic properties of the data, offering a means to optimize parameters without established ground truth. Once representations were derived, complementary gene lists could be further compressed to generate a low complexity dataset, or to probe for individual features with >95% accuracy. We demonstrate the utility of sparse learning as a means to derive biologically meaningful representations from transcriptomic data and reduce the complexity of large datasets while preserving intelligible gene information throughout the analysis.
The mechanochemical origins of the microtubule sliding motility within the kinesin-5 domain organization
Authors: Nithianantham Stanley , Iwanski Malina K. , Gaska Ignas , Pandey Himanshu , Bodrug Tatyana , Inagaki Sayaka , Major Jennifer , Brouhard Gary J. , Gheber Larissa , Rosenfeld Steven S. , Forth Scott , Hendricks Adam G. , Al-Bassam Jawdat
Published: October 2021

The conserved kinesin-5 bipolar tetrameric motors slide apart microtubules during mitotic spindle assembly and elongation. Kinesin-5 bipolar organization originates from its conserved tetrameric helical minifilament, which position the C-terminal tail domains of two subunits near the N-terminal motor domains of two anti-parallel subunits (Scholey et al, 2014). This unique tetrameric structure enables kinesin-5 to simultaneously engage two microtubules and transmit forces between them, and for multiple kinesin-5 motors to organize via tail to motor interactions during microtubule sliding (Bodrug et al, 2020). Here, we show how these two structural adaptations, the kinesin-5 tail-motor domain interactions and the length of the tetrameric minifilament, determine critical aspects of kinesin-5 motility and sliding mechanisms. An x-ray structure of the 34-nm kinesin-5 minifilament reveals how the dual dimeric N-terminal coiled-coils emerge from the tetrameric central bundle. Using this structure, we generated active bipolar mini-tetrameric motors from Drosophila and human orthologs, which are half the length of native kinesin-5. Using single-molecule motility assays, we show that kinesin-5 tail domains promote mini-tetramers static pauses that punctuate processive motility. During such pauses, kinesin-5 mini-tetramers form multi-motor clusters mediated via tail to motor domain cross-interactions. These clusters undergo slow and highly processive motility and accumulate at microtubule plus-ends. In contrast to native kinesin-5, mini-tetramers require tail domains to initiate microtubule crosslinking. Although mini-tetramers are highly strained in initially aligning microtubules, they slide microtubules more efficiently than native kinesin-5, due to their decreased minifilament flexibility. Our studies reveal that the conserved kinesin-5 motor-tail mediated clustering and the length of the tetrameric minifilament are key features for sliding motility and are critical in organizing microtubules during mitotic spindle assembly and elongation.
Requirements for mammalian promoters to decode transcription factor dynamics
Authors: Antwi Enoch B. , Marrakchi Yassine , Çiçek Özgün , Brox Thomas , Di Ventura Barbara
Published: October 2021

In response to different stimuli many transcription factors (TFs) display different activation dynamics that trigger the expression of specific sets of target genes, suggesting that promoters have a way to decode them. Combining optogenetics, deep learning-based image analysis and mathematical modeling, we find that decoding of TF dynamics occurs only when the coupling between TF binding and transcription pre-initiation complex formation is inefficient and that the ability of a promoter to decode TF dynamics gets amplified by inefficient translation initiation. Furthermore, we propose a theoretical mechanism based on phase separation that would allow a promoter to be activated better by pulsatile than sustained TF signals. These results provide an understanding on how TF dynamics are decoded in mammalian cells, which is important to develop optimal strategies to counteract disease conditions, and suggest ways to achieve multiplexing in synthetic pathways.
Differential growth rates and in vitro drug susceptibility to currently used drugs for multiple isolates of Naegleria fowleri
Authors: Russell A. Cassiopeia , Kyle Dennis E.
Published: October 2021

The free-living amoeba, Naegleria fowleri, which typically dwells within warm, freshwater environments, can opportunistically cause Primary Amoebic Meningoencephalitis (PAM), a disease with a mortality rate of >98%, even with the administration of the best available drug regimens. The lack of positive outcomes for PAM has prompted a push for the discovery and development of more effective therapeutics, but most studies only utilize one or two clinical isolates in their drug discovery assays. The inability to assess possible heterogenic responses to drugs among isolates from varying geographical regions hinders progress in the field due to a lack of proven universal efficacy for novel therapeutics. Herein we conducted drug efficacy and growth rate determinations for 11 different clinical isolates, including one obtained from a successful treatment outcome, by applying a previously developed CellTiter-Glo 2.0 screening technique and flow cytometry. We found some significant differences in the susceptibility of these isolates to 7 of 8 different drugs tested, all of which comprise the cocktail that is recommended to physicians by the Centers for Disease Control. We also discovered significant variances in growth rates among isolates which draws attention to the dissidence among the amoebae populations collected from different patients. The findings of this study reiterate the need for inclusion of additional clinical isolates of varying genotypes in drug assays and highlight the necessity for more targeted therapeutics with universal efficacy across N. fowleri isolates. Our data establishes a needed baseline for drug susceptibility among clinical isolates and provides a segue for future combination therapy studies as well as research related to phenotypic or genetic differences that could shed light on mechanisms of action or predispositions to specific drugs.
APOBEC mutagenesis is low in most types of non-B DNA structures, unlike other types of cancer mutagenesis
Authors: Ponomarev Gennady V. , Fatykhov Bulat , Nazarov Vladimir A. , Abasov Ruslan , Shvarov Evgeny , Landik Nina-Vicky , Denisova Alexandra A. , Chervova Almira A. , Gelfand Mikhail S. , Kazanov Marat D.
Published: October 2021

While somatic mutations are known to be enriched in genome regions with non-canonical DNA secondary structure, the impact of particular mutagens still needs to be elucidated. Here, we demonstrate that in human cancers, the APOBEC mutagenesis is not enriched in direct repeats, mirror repeats, short tandem repeats, and G-quadruplexes, and even decreased below its level in B-DNA for cancer samples with very high APOBEC activity. In contrast, we observe that the APOBEC-induced mutational density is positively associated with APOBEC activity in inverted repeats (cruciform structures), where the impact of cytosine at the 3’-end of the hairpin loop is substantial. Surprisingly, the APOBEC-signature mutation density per TC motif in the single-stranded DNA of a G-quadruplex (G4) is lower than in the four-stranded part of G4 and in B-DNA. The APOBEC mutagenesis, as well as the UV-mutagenesis in melanoma samples are absent in Z-DNA regions, due to depletion of their mutational signature motifs.
Nephronectin-Integrin α8 signaling is required for proper migration of periocular neural crest cells during chick corneal development
Authors: Ma Justin , Bi Lian , Spurlin James , Lwigale Peter
Published: October 2021

During development, cells aggregate at tissue boundaries to form normal tissue architecture of organs. However, how cells are segregated into tissue precursors remains largely unknown. Cornea development is a perfect example of this process whereby neural crest cells aggregate in the periocular region prior to their migration and differentiation into corneal cells. Our recent RNA-Seq analysis identified upregulation of Nephronectin (Npnt) transcripts during early stages of corneal development where its function has not been investigated. We found that Npnt mRNA and protein are expressed by various ocular tissues including the migratory periocular neural crest (pNC), which also express the integrin alpha 8 (Itgα8) receptor. Knockdown of either Npnt or Itgα8 attenuated cornea development, whereas overexpression of Npnt resulted in cornea thickening. Moreover, overexpression of Npnt variants lacking RGD binding sites did not affect corneal thickness. Neither the knockdown or augmentation of Npnt caused significant changes in cell proliferation, suggesting that Npnt directs pNC migration into the cornea. In vitro analyses showed that Npnt promotes pNC migration from explanted periocular mesenchyme, which requires Itgα8. Combined, these findings show that Npnt specifies and tunes cell migration into the presumptive cornea ECM by providing a substrate for Itgα8-positive pNC cells.
Formation of a macrocycle from dichlorodimethylsilane and a pyridoxalimine Schiff base ligand
Authors: Böhme Uwe , Schwarzer Anke , Günther Betty
Published: October 2021

The reaction of dichlorodimethylsilane with a polydentate Schiff base ligand derived from pyridoxal and 2-ethanolamine yielded the macrocyclic silicon compound (8E,22E)-4,4,12,18,18,26-hexamethyl-3,5,17,19-tetraoxa-8,13,22,27-tetraaza-4,18-disilatricyclo[22.4.0.010,15]octacosa-1(24),8,10,12,14,22,25,27-octaene-11,25-diol, C24H36N4O6Si2. The asymmetric unit contains the half macrocycle with an intramolecular O—H...N hydrogen bond between the imine nitrogen atom and a neighbouring oxygen atom. The crystal structure is dominated by C—H...O and C—H...π interactions, which form a high ordered molecular network.
Hydrogen-bonding landscape of the carbamoylcyanonitrosomethanide anion in the crystal structure of its ammonium salt
Authors: Domasevitch Kostiantyn V. , Senchyk Ganna A. , Lysenko Andrey B. , Rusanov Eduard B.
Published: October 2021

The structure of the title salt, ammonium carbamoylcyanonitrosomethanide, NH4
+·C3H2N3O2
−, features the co-existence of different hydrogen-bonding patterns, which are specific to each of the three functional groups (nitroso, carbamoyl and cyano) of the methanide anion. The nitroso O-atoms accept as many as three N—H...O bonds from the ammonium cations [N...O = 2.688 (3)–3.000 (3) Å] to form chains of fused rhombs [(NH4)(O)2]. The most prominent bonds of the carbamoyl groups are mutual and they yield 21 helices [N...O = 2.903 (2) Å], whereas the cyano N-atoms accept hydrogen bonds from sterically less accessible carbamoyl H-atoms [N...N = 3.004 (3) Å]. Two weaker NH4
+...O=C bonds [N...O = 3.021 (2), 3.017 (2) Å] complete the hydrogen-bonded environment of the carbamoyl groups. A Hirshfeld surface analysis indicates that the most important interactions are overwhelmingly O...H/H...O and N...H/H...N, in total accounting for 64.1% of the contacts for the individual anions. The relatively simple scheme of these interactions allows the delineation of the supramolecular synthons, which may be applicable to crystal engineering of hydrogen-bonded solids containing polyfunctional methanide anions.
Crystal structure of 2-oxo-1,2-diphenylethyl diisopropylcarbamate
Authors: Martens Viktor , Görls Helmar , Imhof Wolfgang
Published: October 2021

The title compound, C21H25NO3, crystallized as a racemic twin in the Sohnke space group P21. In the molecular structure of the title compound, both enantiomers show a highly similar conformation with the urethane function and the benzoyl group showing an almost perpendicular arrangement [the dihedral angle is 72.46 (8)° in the S-enantiomer and 76.21 (8)° in the R-enantiomer]. In the crystal structure, molecules of both enantiomers show infinite helical arrangements parallel to the b axis formed by weak C—H...O hydrogen bonds between the phenyl ring of the benzoyl group and the carbamate carbonyl group. In case of the R-enantiomer, this helix is additionally stabilized by a bifurcated hydrogen bond between the carbonyl function of the benzoyl group towards both phenyl groups of the molecule.
Distributed robust H∞ adaptive fault-tolerant control of amorphous and flat air-to-ground wireless self-organizing network system
Authors: Wang Zhifang , Yu Jianguo , Lin Shangjing , Dong Junguo , Yu Zheng
Published: October 2021

Purpose

The paper takes the air-ground integrated wireless ad hoc network-integrated system as the research object, this paper aims to propose a distributed robust H∞ adaptive fault-tolerant control algorithm suitable for the system to distribute to solve the problem of control and communication failure at the same time.

Design/methodology/approach

In the paper, the authors propose a distributed robust H∞ adaptive fault-tolerant control algorithm suitable for the air-ground integrated wireless ad hoc network-integrated system.

Findings

The results show that the integrated system has good robustness and fault tolerance performance indicators for flight control and wireless signal transmission when confronted with external disturbances, internal actuator failures and wireless network associated failures and the flight control curve of the quadrotor unmanned aerial vehicle (UAV) is generally smooth and stable, even if it encounters external disturbances and actuator failures, its fault tolerance performance is very good. Then in the range of 400–800 m wireless communication distance, the success rate of wireless signal loop transmission is stable at 80%–100% and the performance is at least relatively improved by 158.823%.

Originality/value

This paper takes the air-ground integrated wireless ad hoc network-integrated system as the research object, based on the robust fault-tolerant control algorithm, the authors propose a distributed robust H∞ adaptive fault-tolerant control algorithm suitable for the system and through the Riccati equation and linear matrix inequation method, the designed distributed robust H∞ adaptive fault-tolerant controller further optimizes the fault suppression factor γ, so as to break through the limitation of only one Lyapunov matrix for different fault modes to distribute to solve the problem of control and communication failure at the same time.
Using Bayesian Kriging for spatial smoothing of trends in non-normal yield densities
Authors: Niyibizi Bart , Brorsen B. Wade , Park Eunchun
Published: October 2021

Purpose

The purpose of this paper is to estimate crop yield densities considering time trends in the first three moments and spatially varying coefficients.

Design/methodology/approach

Yield density parameters are assumed to be spatially correlated, through a Gaussian spatial process. This study spatially smooth multiple parameters using Bayesian Kriging.

Findings

Assuming that county yields follow skew normal distributions, the location parameter increased faster in the eastern and northwestern counties of Iowa, while the scale increased faster in southern counties and the shape parameter increased more (implying less left skewness) in southwestern counties. Over time, the mean has increased sharply, while the variance and left skewness increased modestly.

Originality/value

Bayesian Kriging can smooth time-varying yield distributions, handle unbalanced panel data and provide estimates when data are missing. Most past models used a two-stage estimation procedure, while our procedure estimates parameters jointly.
Effects of quantity promotional frames on inaction inertia
Authors: Liu Hsin-Hsien , Chou Hsuan-Yi
Published: October 2021

Purpose

Inaction inertia is the phenomenon in which people are less likely to accept an opportunity after having previously missed a relatively superior one. This research explores how framing quantity promotions as either a freebie (e.g. “buy 1, get 1 free”) or a price bundle (e.g. “buy 2, get 50% off”) influences inaction inertia. Relevant mediators are also identified.

Design/methodology/approach

Three experiments, two using imaginary scenarios and one using an incentive-compatible design, test the hypotheses.

Findings

Consumers who miss a freebie quantity promotion express higher inaction inertia than consumers who miss a price bundle promotion. The cause of this difference is higher perceived regret and greater devaluation that result from missing a superior freebie (vs price bundle) promotion.

Research limitations/implications

Future research should examine how factors influencing perceived regret and devaluation moderate the quantity promotional frame effect on inaction inertia.

Practical implications

The findings provide insights into which quantity promotional frames practitioners should use to reduce inaction inertia.

Originality/value

This study's comprehensive theoretical framework predicts quantity promotional frame effects on inaction inertia and identifies relevant internal mechanisms. The findings are evidence that inaction inertia is caused by both perceived regret and devaluation in certain contexts. Furthermore, this study identifies the conditions in which a price bundle promotional frame is more beneficial than a freebie promotional frame.
The impact of green finance and Covid-19 on economic development: capital formation and educational expenditure of ASEAN economies
Authors: Ngo Quang-Thanh , Tran Hoa Anh , Tran Hai Thi Thanh
Published: October 2021

Purpose

The purpose of this study is to examine the impact of green finance (i.e. green investment, green security and green credit) along with capital formation and government educational expenditures on the economic development of (ASEAN) countries.

Design/methodology/approach

The data were gathered from the central banks of all ASEAN countries and the World Bank Indicators between 2008 and 2019. The fixed-effect model and generalized method of moments were used to check the nexus between the constructs.

Findings

The results revealed that green finance along with capital formation and government educational expenditures have a positive association with the economic development of ASEAN countries.

Research limitations/implications

The study carries some limitations, even though it addresses the underlying variables comprehensively. These limitations provide opportunities to future researchers and authors to expand the scope and accuracy of their study. This research investigation has been supported by the data collected from a single source. Though data collection is maintained correctly, it is still recommended to the upcoming scholars to acquire data to reconfirm the same findings using multiple data sources. The data collected from using some specific data source may be limited in scope and may hinder the comprehensive elaboration of the underlying variables and their mutual relationship. Therefore, the utilization of multiple sources of data collection gives data sufficient to meet the requirement of an okay quality research study. The study is about the economies of ASEAN countries. It checks the influences of green finance development on economic activities and the country's economic growth in ASEAN countries' economies. Thus, its results are valid only in the economies of these countries, and this research investigation lacks generalizability. For generalizability, the authors must consider the underlying variables in the world's vast economies. They must adopt a standard scale to judge the impacts of green financial development on economic development. Besides, the study analyzes the economic factors, economic conditions and their effects on the country's position in the world economy in the face of a severe epidemic like COVID-19. Thus, the results may be different in the case of the normal situation. So, a general standardized study is recommended to be conducted in the upcoming days.

Originality/value

Green finance has significant capability to improve the global economy, especially amidst the COVID-19 pandemic. This study is beneficial for policymakers to develop policies related to economic development with reference to green finance and also helps future research on a similar topic.
The influence of stacking technologies on structural dynamic properties of electric motors iron cores
Authors: Mönninghoff Sebastian , Jaeger Markus , Hameyer Kay
Published: October 2021

Purpose

It is essential to understand the structural dynamic behavior of electrical machines to predict their acoustic and vibrational behavior. Stacking technology, which is used to manufacture soft magnetic cores, has a strong influence on the material properties. The purpose of this paper is therefore to research the influence of the stacking technologies welding and bonding with bake varnish on the modal properties of iron cores.

Design/methodology/approach

A finite element simulation model is developed based on homogenization of the stator core. Eigenfrequencies, modeshapes and modal damping ratios are extracted from measurements and are used to validate the simulation model.

Findings

Modal characteristics depend on the participation of certain material layers at a certain mode. Higher amount of shear deformation results in higher modal damping. Bonded stacks exhibit lower shear stiffness and higher damping ratios.

Originality/value

This research paper provides insights to the modal characteristics of iron cores used in electric machine and compares the influence of stacking technologies.
Quantifying costs of the productivity loss due to schedule changes in construction projects
Authors: Lee Jae-Seob
Published: October 2021

Purpose

The purpose of the paper is to develop a method to integrate the schedule-based analysis with a productivity-based analysis to prove and support the result of the damages calculation.

Design/methodology/approach

In this paper, a “cost and schedule impact integration” (CSI2) model is proposed to objectively show and estimate lost productivity due to changes in construction projects.

Findings

A schedule-based analysis to include separate tracking of change order costs can be used to predict productivity due to the delay and disruption; changes in construction projects almost always result in delay and disruption. However, the schedule-based analysis needs to be integrated with a productivity-based analysis to prove and support the result of the damages calculation.

Practical implications

The results of this study expand upon construction practices for proving and quantifying lost productivity due to changes in construction projects.

Originality/value

The contribution of the paper is summarized as the introduction of a “schedule impact analysis” into a “cost impact analysis” technique to assess the damages, as well as to demonstrate the labor productivity impact due to delay and disruption in construction projects.
The impact of entrepreneurship education and cultural context on entrepreneurial intentions of Ukrainian students: the mediating role of attitudes and perceived control
Authors: Mykolenko Olena , Ippolitova Inna , Doroshenko Hanna , Strapchuk Svitlana
Published: October 2021

Purpose

The purpose of the research is to test empirically whether the variables of personal attitudes towards entrepreneurship and perceived control mediate the relationship between entrepreneurship education and intentions of Ukrainian students to become entrepreneurs; to determine whether personal attitudes mediate the relationship between cultural context and entrepreneurial intentions.

Design/methodology/approach

The research project carried out jointly by four Kharkiv universities used 349 survey responses from senior students majoring in business and economics and management and marketing. The data was analysed using Partial Least Squares regression.

Findings

Education and employed teaching methods, in particular, positively affect students' attitudes towards entrepreneurship, their perceived capability to start a business and indirectly influence entrepreneurial intentions. However, attendance of entrepreneurship-related courses itself does not enhance perceived control and has no significant effect on personal attitudes. The study also shows that cultural context has a positive influence on students' attitudes towards entrepreneurship and, therefore, indirectly impacts their intentions to become entrepreneurs.

Research limitations/implications

Firstly, the students participating in the study were from one country. And secondly, the paper deals with pre-educational entrepreneurial intentions.

Practical implications

The study suggests that a practice-based approach to entrepreneurship education is a key to raising entrepreneurial awareness of young people in countries whose national cultures are built on collectivist values.

Originality/value

The results of the study are of value for teaching staff, who can actually influence students' entrepreneurial self-awareness, and for university management in the context of contemporary education reforms and the latest requirements to education process.
Sentiment analysis in hospitality and tourism: a thematic and methodological review
Authors: Mehraliyev Fuad , Chan Irene Cheng Chu , Kirilenko Andrei Petrovich
Published: October 2021

Purpose

This study aims to conduct a systematic review and critically analyze the sentiment analysis literature in hospitality and tourism from methodological (data sets and analyzes) and thematic (topics, theories, key constructs and their relationships) perspectives.

Design/methodology/approach

Qualitative thematic review and quantitative systematic review were performed on 70 papers obtained from hospitality and tourism categories of two databases, namely, Web of Science and Scopus.

Findings

A total of 5 topics and 27 sub-topics were identified and the major theme is market intelligence. Sentiment variables were investigated not only as independent but also as dependent variables. The customer rating is the most investigated dependent variable, whereas moderators and mediators were rarely tested. Most reviewed studies did not use theory. The findings from the methodological review show that analysis of big data was rare. Moreover, testing the performance of sentiment analyzes was uncommon, and only one paper tested the performance of aspect/feature extraction.

Research limitations/implications

This study extends prior review studies by providing a comprehensive view of how knowledge and methodologies of sentiment analysis have developed. The identified themes and key constructs serve as a solid base for future knowledge advancement. Future research directions on sentiment analysis are also provided.

Originality/value

To the best of the authors’ knowledge, this study is the first comprehensive methodological and thematic review of sentiment analysis in hospitality and tourism. Based on the identified findings, the authors propose several directions for future research.
Image, eventscape, satisfaction and loyalty: a case study of a wine tourism event
Authors: Goncalves Olga , Camprubí Raquel , Fons Cendrine , Solonandrasana Bernardin
Published: October 2021

Purpose

Eventscape is widely recognised as having played an important role in the image of wine events; however, research on this topic is scarce, with only a few studies examining the image of a wine tourism event. To date, no studies have examined eventscape and attitudinal variables of a wine event together, thus indicating a gap in the research. Further research to gain a deeper understanding of the role these factors play is needed; thus, this paper aims to explore the relationships between event image, eventscape, satisfaction and loyalty in wine events.

Design/methodology/approach

A structured questionnaire was chosen for data collection, with a final sample of 117 valid responses. Qualitative data was analysed by means of content analysis. Univariate and bivariate statistical analyses were performed to analyse eventscape attributes and explore its relationship with event image, satisfaction and loyalty.

Findings

The paper highlights that perceptions of eventscape are intrinsically related to perceived event image and reveal a statistically significant relationship between these two elements. Results show the importance of the social dimension in the image perception of a wine event and point to conviviality as the main element. This study also reveals a relationship between perceived event image and attitudinal variables and suggests that having a positive image of the event positively influences levels of satisfaction, which are higher, and willingness to participate in future editions of the event. Findings also reveal a relationship between event image and loyalty.

Originality/value

Wine-related events are undergoing significant developments, creating a need for competitive strategies to develop wine tourism and vineyards in certain regions. Research in this field is scarce to date; therefore, this paper adds to the literature by the studying consumer behaviour of attendees at wine events.
The role of online social networks in university students’ environmentally responsible behavior
Authors: Rezaei Amirreza , Ahmadi Saba , Karimi Hamid
Published: October 2021

Purpose

This study aims to determine the effect of online social networks on university students’ environmentally responsible behavior (ERB). This research aimed to develop and test a behavioral model in the context of online social networks, where students’ attitudes, knowledge and behavior influence their ERB.

Design/methodology/approach

This study used a quasi-experiment with a pretest-posttest design and a random parallelization control group. The research used a questionnaire to assess ERB, environmental attitudes and environmental knowledge. The researcher randomly assigned 120 students to an experimental and a control group of equal size. Both groups initially completed a pretest. The experimental group was trained in environmental issues over four months (an academic semester) via an online social network.

Findings

The findings indicated that the social network had a significant effect on motivating ERB. Additionally, it improved environmental attitudes. According to the results, online social networks such as Facebook can significantly aid in teaching and learning environmental issues in formal academic settings.

Originality/value

Online social networks facilitated significant cognitive progress in environmental education. The primary objective is to educate students about ERB.