bluuebunny/crossref_metadata_2025 huggingface dataset:
Species turnover between age groups of horses and positive network of co-occurrences define the structure of horse strongylid communities: a meta-analysis
Authors: Boisseau Michel , Mach Núria , Basiaga Marta , Kornaś Sławomir , Kuzmina Tetiana , Laugier Claire , Sallé Guillaume
Published: May 2021

Grazing horses are infected by a wide range of strongylid species mostly located in the large intestine. Despite their impact on equine health and the emergence of drug resistant isolates, the phenology of these nematodes has been poorly characterized and the rules structuring their assembly as a community are not understood. Here, we compiled data on 46 equine strongylid species collected worldwide at the regional or horse scales (upon deworming or after necropsy) to analyse their richness, diversity and associated factors of variation. Worldwide, twelve species from the Cylicocyclus (n = 4), Cylicostephanus (n = 3), Coronocyclus (n = 2) and Cyathostomum (n = 2) genera were found in at least 75% of sites. Geoclimatic conditions had a limited effect on strongylid communities, but reduced species richness was found under the temperate European area. The recovery method did not affect species richness and differences on the temporal and sampling effort scales between studies applying either methods underpinned heterogeneous variances in community diversity.

At the horse level, rarefaction curves correlated poorly to parasite egg excretion, suggesting little contribution of community diversity to this trait. Using a diversity partitioning approach, we found that within-host diversity represented half of overall diversity underscoring the importance of host density and environmental contamination to the diversity of strongylid communities. While this is expected to erase diversity across communities, species turnover between age classes was the second most important contributor to overall diversity (23.9%). This was associated with a network of positive co-occurrences between the four most prevalent genera that we resolved at the anatomical niche level. Altogether this pattern of β-diversity maintenance across age classes combined with positive co-occurrences may be grounded by priority effects between major species. Our findings set the first assembly rules of equine strongylid communities.
Functional analysis of Ost3p and Ost6p containing yeast oligosaccharyltransferases
Authors: Neuhaus Julia D. , Wild Rebekka , Eyring Jillianne , Irobalieva Rossitza N. , Kowal Julia , Lin Chia-wei , Locher Kaspar P. , Aebi Markus
Published: May 2021

The oligosaccharyltransferase (OST) is the central enzyme in theN-glycosylation pathway. It transfers a defined oligosaccharide from a lipid-linker onto the asparagine side chain of proteins. The yeast OST consists of eight subunits and exists in two catalytically distinct isoforms that differ in one subunit, Ost3p or Ost6p. The cryo-electron microscopy structure of the Ost6p containing complex was found to be highly similar to the Ost3p containing OST. OST enzymes with altered Ost3p/Ost6p subunits were generated and functionally analysed. The three C-terminal transmembrane helices were responsible for the higher turnover-rate of the Ost3p vs. the Ost6p containing enzymein vitroand the more severe hypoglycosylation in Ost3p lacking strainsin vivo. Glycosylation of specific OST target sites required the N-terminal thioredoxin domain of Ost3p or Ost6p. This Ost3p/Ost6p dependence was glycosylation site but not protein specific. We concluded that the Ost3p/Ost6p subunits modulate the catalytic activity of OST and provide additional specificity for OST substrate recognition.
3D matrix adhesion composition facilitates nuclear force coupling to drive invasive cell migration
Authors: Newman Daniel , Young Lorna , Waring Thomas , Brown Louise , Wolanska Katarzyna , Macdonald Ewan , Orszag Arthur Charles , Caswell Patrick , Sakuma Tetsushi , Yamamoto Takashi , Machesky Laura , Morgan Mark , Zech Tobias
Published: May 2021

Cell invasion and metastasis is a multi-step process, initialised through the acquisition of a migratory phenotype and the ability to move through differing and complex 3D extracellular environments. In this study we set out to identify the parameters required for invasive cell migration in 3D environments. Cells interact with the extracellular matrix via transmembrane-spanning integrin adhesion complexes, which are well characterised in cells plated on 2D surfaces, yet much less is known about them in cells embedded in 3D matrices. We establish a technique to determine the composition of cell matrix adhesion complexes of invasive breast cancer cells in 3D matrices and on 2D surfaces and we identify an interaction complex enriched in 3D adhesive sites required for 3D invasive migration. Depletion of β-PIX-Myosin18A (Myo18A) abolishes cancer cell invasion, without negatively affecting matrix degradation, Rho GTPase signalling, or protrusion formation in collagen matrices. Instead, in a mechanism only seen in cells moving through 3D matrix, β-PIX and Myo18A drive the polarised recruitment of non-muscle Myosin 2A (NM2A) to the tips of protrusions. This recruitment of NM2A is required for the creation of an NM2A-NM2B isoform gradient, which ranges from the protrusion to the nucleus. We observe a requirement for active force transmission to the nucleus during invasive migration that is needed to pull the nucleus forward. We postulate that the establishment of the NM2A-NM2B actomyosin gradient facilitates the coupling of cell-matrix interactions at the protrusive cell front with nuclear movement, enabling effective invasive migration and front-rear cell polarity.
Hidden viral sequences in public sequencing data and warning for future emerging diseases
Authors: Kawasaki Junna , Kojima Shohei , Tomonaga Keizo , Horie Masayuki
Published: May 2021

RNA viruses cause numerous emerging diseases, mostly due to transmission from mammalian and avian reservoirs. Large-scale surveillance of RNA viral infections in these animals is a fundamental step for controlling viral infectious diseases. Metagenomic analysis is a powerful method for virus identification with low bias and has substantially contributed to the discovery of novel viruses. Deep sequencing data have been collected from diverse animals and accumulated in public databases, which can be valuable resources for identifying unknown viral sequences. Here, we screened for infections of 33 RNA viral families in publicly available mammalian and avian sequencing data and found approximately 900 hidden viral infections. We also discovered six nearly complete viral genomes in livestock, wild, and experimental animals: hepatovirus in a goat, hepeviruses in blind mole-rats and a galago, astrovirus in macaque monkeys, parechovirus in a cow, and pegivirus in tree shrews. Some of these viruses were phylogenetically close to human pathogenic viruses, suggesting the potential risk of causing disease in humans upon infection. Furthermore, the infections of five novel viruses were identified in several different individuals, indicating that their infections may have already spread in the natural host population. Our findings demonstrate the reusability of public sequencing data for surveying viral infections and identifying novel viral sequences, presenting a warning about a new threat of viral infectious disease to public health.

Importance

Monitoring the spread of viral infections and identifying novel viruses capable of infecting humans through animal reservoirs are necessary to control emerging viral diseases. Massive amounts of sequencing data collected from various animals are publicly available, and these data may contain sequences originating from a wide variety of viruses. Here, we analyzed more than 46,000 public sequencing data and identified approximately 900 hidden RNA viral infections in mammalian and avian samples. Some viruses discovered in this study were genetically similar to pathogens that cause hepatitis, diarrhea, or encephalitis in humans, suggesting the presence of new threats to public health. Our study demonstrates the effectiveness of reusing public sequencing data to identify known and unknown viral infections, indicating that future continuous monitoring of public sequencing data by metagenomic analyses would help prepare and mitigate future viral pandemics.
Probabilistically Weighted Multilayer Networks disclose the link between default mode network instability and psychosis-like experiences in healthy adults
Authors: Di Plinio Simone , Ebisch Sjoerd J H
Published: May 2021

The brain is a complex system in which the functional interactions among its subunits vary over time. The trajectories of this dynamic variation contribute to inter-individual behavioral differences and psychopathologic phenotypes. Despite many methodological advancements, the study of dynamic brain networks still relies on biased assumptions in the temporal domain. The current paper has two goals. First, we present a novel method to study multilayer networks: by modelling intra-nodal connections in a probabilistic, biologically driven way, we introduce a temporal resolution of the multilayer network based on signal similarity across time series. This new method is tested on synthetic networks by varying the number of modules and the sources of noise in the simulation. Secondly, we implement these probabilistically weighted (PW) multilayer networks to study the association between network dynamics and subclinical, psychosis-relevant personality traits in healthy adults. We show that the PW method for multilayer networks outperforms the standard procedure in modular detection and is less affected by increasing noise levels. Additionally, the PW method highlighted associations between the temporal instability of default mode network connections and psychosis-like experiences in healthy adults. PW multilayer networks allow an unbiased study of dynamic brain functioning and its behavioral correlates.
Genomic contacts reveal the control of sister chromosome decatenation in E. coli
Authors: Conin Brenna , Billault-Chaumartin Ingrid , Sayyed Hafez El , Cockram Charlotte , Koszul Romain , Espéli Olivier
Published: May 2021

In bacteria, chromosome segregation occurs progressively, from the origin to the terminus, a few minutes after the replication of each locus. In-between replication and segregation, sister loci are maintained in an apparent cohesive state by topological links. Whereas topoisomerase IV (Topo IV), the main bacteria decatenase, controls segregation, little is known regarding the influence of the cohesion step on chromosome folding. In this work, we investigated chromosome folding in cells with altered decatenation activities. Within minutes after Topo IV inactivation, a massive chromosome reorganization takes place, associated with increases in trans-contacts between catenated sister chromatids and in long-range cis-contacts between the terminus and distant loci on the genome. A genetic analysis of these signals allowed us to decipher specific roles for Topo IV and Topo III, an accessory decatenase. Moreover we revealed the role of MatP, the terminus macrodomain organizing system and MukB, the E. coli SMC in organizing sister chromatids tied by persistent catenation links. We propose that large-scale conformation changes observed in these conditions reveal a defective decatenation hub located in the terminus area. Altogether, our findings support a model of spatial and temporal partition of the tasks required for sister chromosome segregation.
The Medaka Inbred Kiyosu-Karlsruhe (MIKK) Panel
Authors: Fitzgerald Tomas , Brettell Ian , Leger Adrien , Wolf Nadeshda , Kusminski Natalja , Monahan Jack , Barton Carl , Herder Cathrin , Aadepu Narendar , Gierten Jakob , Becker Clara , Hammouda Omar T. , Hasel Eva , Lischik Colin , Lust Katharina , Suzuki Risa , Tsingos Erika , Tavhelidse Tinatini , Thumberger Thomas , Watson Philip , Welz Bettina , Khouja Nadia , Naruse Kiyoshi , Birney Ewan , Wittbrodt Joachim , Loosli Felix
Published: May 2021

Unraveling the relationship between genetic variation and phenotypic traits remains a fundamental challenge in biology. Mapping variants underlying complex traits while controlling for confounding environmental factors is often problematic. To address this, we have established a vertebrate genetic resource specifically to allow for robust genotype-to-phenotype investigations. The teleost medaka (Oryzias latipes) is an established genetic model system with a long history of genetic research and a high tolerance to inbreeding from the wild. Here we present the Medaka Inbred Kiyosu-Karlsruhe (MIKK) panel: the first near-isogenic panel of 80 inbred lines in a vertebrate model derived from a wild founder population. Inbred lines provide fixed genomes that are a prerequisite for the replication of studies, studies which vary both the genetics and environment in a controlled manner and functional testing. The MIKK panel will therefore enable phenotype-to-genotype association studies of complex genetic traits while allowing for careful control of interacting factors, with numerous applications in genetic research, human health, and drug development and fundamental biology. Here we present a detailed characterisation of the genetic variation across the MIKK panel, which provides a rich and unique genetic resource to the community by enabling large-scale experiments for mapping complex traits.
Lactate is a major energy substrate for cortical neurons and enhances their firing activity
Authors: Karagiannis Anastassios , Gallopin Thierry , Lacroix Alexandre , Plaisier Fabrice , Piquet Juliette , Geoffroy Hélène , Hepp Régine , Naudé Jérémie , Le Gac Benjamin , Egger Richard , Lambolez Bertrand , Li Dongdong , Rossier Jean , Staiger Jochen F. , Imamura Hiromi , Seino Susumu , Roeper Jochen , Cauli Bruno
Published: May 2021

Glucose is the mandatory fuel for the brain, yet the relative contribution of glucose and lactate for neuronal energy metabolism is unclear. We found that increased lactate, but not glucose concentration, enhances the spiking activity of neurons of the cerebral cortex. Enhanced spiking was dependent on ATP-sensitive potassium (KATP) channels formed with Kir6.2 and SUR1 subunits, which we show are functionally expressed in most neocortical neuronal types. We also demonstrate the ability of cortical neurons to take-up and metabolize lactate. We further reveal that ATP is produced by cortical neurons largely via oxidative phosphorylation and only modestly by glycolysis. Our data demonstrate that in active neurons, lactate is preferred to glucose as an energy substrate, and that lactate metabolism shapes neuronal activity in the neocortex through KATP channels. Our results highlight the importance of metabolic crosstalk between neurons and astrocytes for brain function.

Highlights

Most cortical neurons subtypes express pancreatic beta-cell like KATP channels.

Lactate enhances spiking activity via its uptake and closure of KATP channels.

Cortical neurons take up and oxidize lactate.

Cortical neurons produce ATP mainly by oxidative phosphorylation.
Comparative analyses and phylogenetic relationships of 15Trapa(Trapaceae) species based on Complete Chloroplast Genomes
Authors: Fan Xiangrong , Wang Wuchao , Wagutu Godfrey K. , Li Wei , Li Xiuling , Chen Yuanyuan
Published: May 2021

TrapaL. is floating-leaved aquatic plants with important economic and ecological values. However, species identification and phylogenetic relationship are still unresolved forTrapa. In this study, complete chloroplast genomes of 13Trapaspecies/taxa were sequenced and annotated. Combined with released sequences of the other two species, comparative analysis of cp genomes was first performed on the 15Trapaspecies/taxa. The 15 cp genomes exhibited quadripartite structures with medium size of 155, 453-155, 559 bp. IR/SC junctions were conservative with no obvious change found. Long repetitive repeats and SSRs were mostly detected in the intergenic and LSC regions, providing useful plastid markers for species and relationship identification. Three phylogenetic analyses (MP, ML and BI) consistently showed two clusters withinTrapa, including large- and small-seed species/taxa, respectively. This study provided the baseline information for phylogeography ofTrapa, which would facilitate the management and utilization of genetic resources of the genus.
Loricarioid catfish evolved skin denticles that recapitulate teeth at the structural, developmental, and genetic levels
Authors: Rivera-Rivera Carlos J. , Guevara-Delgadillo Nadezhda I. , Bahechar Ilham A. , Shea Claire A. , Montoya-Burgos Juan I.
Published: May 2021

The first vertebrate mineralized skeleton was an external bony armor coated with dental structures. The subsequent emergence of a mineralized endoskeleton and of teeth are considered key innovations in the diversification of vertebrates. Although time clouds our understanding of the initial evolution of these mineralized structures, recent re-emergences may shed light on the underlying processes. Loricarioid catfishes are a lineage that, much like the ancestral vertebrates, bear denticle-clad bony armor from head to tail. Loricarioid denticles (LDs) and oral teeth are very similar in superstructure. We show here that other extra-oral dental structures are found as ancestral characters only in lineages that are distantly related to loricarioids such as sharks or coelacanth, indicating that LDs have independently re-emerged in loricarioid catfishes. We investigate whether the similarities between LDs and teeth extend to their developmental and genetic context, and how their development compares to that of other vertebrate integument structures. Our detailed study of the development of LDs, and gene expression analyses through in situ hybridization confirm that all 12 genes from the tooth-forming gene regulatory network (oGRN) are expressed in developing LDs in a similar way as they are expressed in developing teeth. We then compare the developmental, structural, and genetic aspects of LD and teeth with that of other integument appendages such as fish scales, shark dermal denticles, feathers and hairs. We find that LDs share all developmental cues with teeth and, to a lesser extent, with the other vertebrate integument structures. Taken together, our results indicate that denticles have re-emerged on the trunk of loricarioid catfishes through the ectopic co-option of the oGRN rather than the resurrection of an ancestral trunk-specific denticle genetic pathway.
Towards risk-based surveillance of African Swine Fever in Switzerland
Authors: Amado Maria Elena Vargas , Carmo Luís Pedro , Berezowski John , Fischer Claude , Santos Maria João , Grütter Rolf
Published: May 2021

African Swine Fever (ASF) has emerged as a disease of great concern to swine producers and government disease control agencies because of its severe consequences to animal health and the pig industry. Early detection of an ASF introduction is considered essential for reducing the harm caused by the disease. Risk-based surveillance approaches have been used as enhancements to early disease epidemic detection systems in livestock populations. Such approaches may consider the role wildlife plays in hosting and transmitting a disease. In this study, a novel method is presented to estimate and map the risk of introducing ASF into the domestic pig population through wild boar intermediate hosts. It makes use of data about hunted wild boar, rest areas along motorways connecting ASF affected countries to Switzerland, outdoor piggeries, and forest cover. These data were used to compute relative wild boar abundance as well as to estimate the risk of both disease introduction into the wild boar population and disease transmission to domestic pigs. The way relative wild boar abundance was calculated adds to the current state of the art by considering the effect of beech mast on hunting success and the probability of wild boar occurrence when distributing relative abundance values among individual grid cells. The risk of ASF introduction into the domestic pig population by wild boar was highest near the borders of France, Germany, and Italy. On the north side of the Alps, areas of high risk were located on the unshielded side of the main motorway crossing the Central Plateau, which acts as a barrier for wild boar. The results of this study can be used to focus surveillance efforts for early disease detection on high risk areas. The developed method may also inform policies to control other diseases that are transmitted by direct contact from wild boar to domestic pigs.
Genomic variations and epigenomic landscape of the Medaka Inbred Kiyosu-Karlsruhe (MIKK) panel
Authors: Leger Adrien , Brettell Ian , Monahan Jack , Barton Carl , Wolf Nadeshda , Kusminski Natalja , Herder Cathrin , Aadepu Narendar , Becker Clara , Gierten Jakob , Hammouda Omar T. , Hasel Eva , Lischik Colin , Lust Katharina , Suzuki Risa , Tavhelidse Tinatini , Thumberger Thomas , Tsingos Erika , Watson Philip , Welz Bettina , Naruse Kiyoshi , Loosli Felix , Wittbrodt Joachim , Birney Ewan , Fitzgerald Tomas
Published: May 2021

The teleost medaka (Oryzias latipes) is a well-established vertebrate model system, with a long history of genetic research, and multiple high-quality reference genomes available for several inbred strains (HdrR, HNI and HSOK). Medaka has a high tolerance to inbreeding from the wild, thus allowing one to establish inbred lines from wild founder individuals. We have exploited this feature to create an inbred panel resource: the Medaka Inbred Kiyosu-Karlsruhe (MIKK) panel. This panel of 80 near-isogenic inbred lines contains a large amount of genetic variation inherited from the original wild population. We used Oxford Nanopore Technologies (ONT) long read data to further investigate the genomic and epigenomic landscapes of a subset of the MIKK panel. Nanopore sequencing allowed us to identify a much greater variety of high-quality structural variants compared with Illumina sequencing. We also present results and methods using a pan-genome graph representation of 12 individual medaka lines from the MIKK panel. This graph-based reference MIKK panel genome revealed novel differences between the MIKK panel lines compared to standard linear reference genomes. We found additional MIKK panel-specific genomic content that would be missing from linear reference alignment approaches. We were also able to identify and quantify the presence of repeat elements in each of the lines. Finally, we investigated line-specific CpG methylation and performed differential DNA methylation analysis across the 12 lines. We thus present a detailed analysis of the MIKK panel genomes using long and short read sequence technologies, creating a MIKK panel specific pan genome reference dataset allowing for the investigation of novel variation types that would be elusive using standard approaches.
Functional or vestigial? The genomics of the pineal gland in Xenarthra
Authors: Valente Raul , Alves Filipe , Pinto Isabel Sousa , Ruivo Raquel , Castro L. Filipe C.
Published: May 2021

Vestigial organs are historical echoes of past phenotypes. Determining whether a specific organ constitutes a functional or vestigial structure can be a challenging task, given that distinct levels of atrophy may arise between and within lineages. The mammalian pineal gland, an endocrine organ involved in melatonin biorhythmicity, represents a classic example, often yielding contradicting anatomical observations. In Xenarthra (sloths, anteaters and armadillos), a peculiar mammalian order, the presence of a distinct pineal organ was clearly observed in some species (i.e. Linnaeus’s two-toed sloth) but undetected in other closely related species (i.e. brown-throated sloth). In the nine-banded armadillo, contradicting evidence supports either functional or vestigial scenarios. Thus, to untangle the physiological status of the pineal gland in Xenarthra, we used a genomic approach to investigate the evolution of the gene hub responsible for melatonin synthesis and signaling. We show that both synthesis and signaling compartments are eroded and were lost independently. Additionally, by expanding our analysis to 157 mammal genomes we offer a comprehensive view showing that species with very distinctive habitats and lifestyles have convergently evolved a similar phenotype: Cetacea, Pholidota, Dermoptera, Sirenia and Xenarthra. Our findings suggest that the recurrent inactivation of melatonin genes correlates with pineal atrophy, and endorse the use of genomic analyses to ascertain the physiological status of suspected vestigial structures.
Megalencephalic leukoencephalopathy with subcortical cysts is a developmental disorder of the gliovascular unit
Authors: Gilbert Alice , Elorza-Vidal Xabier , Rancillac Armelle , Chagnot Audrey , Yetim Mervé , Hingot Vincent , Deffieux Thomas , Boulay Anne-Cécile , Alvear-Perez Rodrigo , Cisternino Salvatore , Martin Sabrina , Taib Sonia , Gelot Antoinette , Mignon Virginie , Favier Maryline , Brunet Isabelle , Declèves Xavier , Tanter Mickael , Estevez Raul , Vivien Denis , Saubaméa Bruno , Cohen-Salmon Martine
Published: May 2021

Absence of the astrocyte-specific membrane protein MLC1 is responsible for megalencephalic leukoencephalopathy with subcortical cysts (MLC); this rare type of leukodystrophy is characterized by early-onset macrocephaly and progressive white matter vacuolation that lead to ataxia, spasticity, and cognitive decline. During postnatal development (from P5 to P15 in the mouse), MLC1 forms a membrane complex with GlialCAM (another astrocytic transmembrane protein) at the junctions between perivascular astrocytic processes (PvAPs, which along with blood vessels form the gliovascular unit (GVU)). We analyzed the GVU in the Mlc1 knock-out mouse model of MLC. The absence of MLC1 led to an accumulation of fluid in the brain but did not modify the endothelial organization or the integrity of the blood-brain barrier. From P10 onward, the postnatal acquisition of vascular smooth muscle cell contractility was altered, resulting in a marked reduction in arterial perfusion and neurovascular coupling. These anomalies were correlated with alterations in astrocyte morphology, astrocyte polarity and the structural organization of the PvAP’s perivascular coverage, and poor intraparenchymal circulation of the cerebrospinal fluid (CSF). Hence, MLC1 is required for the postnatal development and organization of PvAPs and controls vessel contractility and intraparenchymal interstitial fluid clearance. Our data suggest that (i) MLC is a developmental disorder of the GVU, and (ii) PvAP and VSMC maturation defects are primary events in the pathogenesis of MLC and therapeutic targets for this disease.
Decoding Angiotensin II Type 1 Receptor Allosteric Communication to Gq and β-arrestin
Authors: Nivedha Anita K. , Cao Yubo , Lee Sangbae , Bhattacharya Supriyo , Laporte Stéphane A. , Vaidehi Nagarajan
Published: May 2021

The allosteric communication between the agonist binding site and the G protein or β-arrestin coupling sites in G protein-coupled receptors (GPCRs) play an important role in determining ligand efficacy towards these two signaling pathways and hence the ligand bias. Knowledge of the amino acid residue networks involved in the allosteric communication will aid understanding GPCR signaling and the design of biased ligands. Angiotensin II type I receptor (AT1R) is an ideal model GPCR to study the molecular basis of ligand bias as it has multiple β-arrestin2 and Gq protein biased agonists as well as three-dimensional structures. Using Molecular Dynamics simulations, dynamic allostery analysis, and functional BRET assays, we identified a network of residues involved in allosteric communication from the angiotensin II binding site to the putative Gq coupling sites and another network to the β-arrestin2 coupling sites, with 6 residues common to both pathways located in TM3, TM5 and TM6. Our findings unveil unique and common allosteric communication residue hubs for Gq and β-arr2 coupling by AngII ligands and suggests that some of these residues can be targeted to design biased AT1R ligands. Finally, we show through analysis of the inter-residue distance distributions of the activation microswitches involved in class A GPCR activation for ten different agonists, that these microswitches behave like rheostats with different relative strengths of activation, which we speculate could modulate the relative efficacy of these agonists toward the two signaling pathways.

Significance Statement

Knowledge of the residues involved in allosteric communication from the ligand binding site to the G protein or β-arrestin (β-arr) coupling sites in GPCRs will aid in understanding their role in mediating ligand bias. Using a combination of molecular dynamics simulations and functional signaling assays we have identified a network of residues involved in allosteric communication from the Angiotensin II (Ang II) binding site to the Gq and β-arr2 coupling sites in the Ang II type I receptor (AT1R). The residues in the allosteric network for β-arr2 coupling are distributed across multiple structural regions of AT1R compared to Gq coupling. The residues in the two networks show conserved chemical properties across class A GPCRs, demonstrating the importance of allosteric communication in modulating ligand bias.
Heritability and phenotypic plasticity of biting time behaviors in the major African malaria vectorAnopheles arabiensis
Authors: Govella Nicodem J. , Johnson Paul C. D. , Killeen Gerry F. , Ferguson Heather M.
Published: May 2021

Use of Insecticide Treated Nets for malaria control has been associated with shifts in mosquito vector feeding behavior including earlier and outdoor biting on humans. The relative contribution of phenotypic plasticity and heritability to these behavioural shifts is unknown. Elucidation of the mechanisms behind these shifts is crucial for anticipating impacts on vector control. We used a novel portable semi-field system (PSFS) to experimentally measure heritability of biting time in the malaria vectorAnopheles arabiensisin Tanzania. In PSFS assays, the biting time of F2 offspring (early: 18:00-21:00, mid: 22:00-04:00 or late: 05:00-07:00) was significantly associated with that of their wild-caught F0 grandmothers, corresponding to an estimated heritability of 0.30 (95% CI: 0.20, 0.41). F2 from early-biting F0 were more likely to bite early than F2 from mid or late late-biting F0. Similarly, the probability of biting late was higher in F2 derived from mid and late-biting F0 than from early-biting F0. Our results indicate that variation in biting time is attributable to additive genetic variation. Selection can therefore act efficiently on mosquito biting times, highlighting the need for control methods that target early and outdoor biting mosquitoes.
Pathogen clonal expansion underlies multiorgan dissemination and organ-specific outcomes during systemic infection
Authors: Hullahalli Karthik , Waldor Matthew K.
Published: May 2021

The dissemination of pathogens through blood and their establishment within organs lead to severe clinical outcomes. However, the within-host dynamics that underly pathogen spread to and clearance from systemic organs remain largely uncharacterized. Here, we investigate the population dynamics of extraintestinal pathogenic E. coli, a common cause of bacteremia, during systemic infection. We show that while bacteria are largely cleared by most organs, organ-specific clearance failures are pervasive and result from dramatic expansions of clones representing less than 0.0001% of the inoculum. Clonal expansion underlies the variability in bacterial burden between animals, and stochastic dissemination of clones profoundly alters the pathogen population structure within organs. Despite variable pathogen expansion events, host bottlenecks are consistent yet highly sensitive to infection variables, including inoculum size and macrophage depletion. Finally, we identify organ-specific bacterial genetic factors that distinguish between establishment of within-organ pathogen populations and subsequent survival or expansion.
Public food procurement for Italian schools: results from analytical and content analyses
Authors: Salvatore Fiorella Pia , Fanelli Simone , Lanza Gianluca , Milone Michele
Published: May 2021

Purpose

The study objective was to understand if uniformity of approach exists in evaluation methods of public food tender for schools at national and local level. This purpose was divided into three sub-objectives: (1) to extract the main criteria, (2) to document the synthesizing findings process and (3) to prioritize the different decision-making alternatives through pairwise comparisons.

Design/methodology/approach

To achieve the sub-objectives (1) and (2), a content analysis of the Italian food tenders was carried out. Analytic hierarchy process was used to evaluate and compare the importance of various food tender evaluation criteria (3). The inclusion criteria were: cities' selection; metro area population; population density; duration of the contract; years.

Findings

Six public food tenders were analyzed. The first one concerned the National legislation guidelines. The remaining five food tenders were categorized according to the city investigated. Four macro-categories (Food quality; Sustainability; Resources; Ancillary services) were classified. AHP revealed that “Food quality” and “Resources” categories have greater importance in the evaluation phase of almost all cities investigated.

Originality/value

This study in-depth analyzes each criterion used to evaluate public food tenders, providing a new methodological framework for assigning scores to clusters of criteria. Since the literature search did not reveal any previous study on a quantitative evaluation of elements such as short supply chain, organic food and environmental impacts on public food tenders, this research delivers interesting results and fills this knowledge gap.
The link between independent directors and firm’s performance: the moderating role of corporate social responsibility
Authors: Tran Hien Thi
Published: May 2021

Purpose

This paper aims to examine how independent directors (IDs) affect a firm’s performance measured on profitability, with corporate social responsibility (CSR) interaction.

Design/methodology/approach

The study uses an international data set of 1,817 firm-year observations from 545 large companies in 20 countries across Asia, America and Europe, and the fixed-effects estimation method.

Findings

The direct effect of IDs alone on profitability is statistically insignificant; however, the synergic effect of IDs and CSR on profitability becomes significantly positive when firms disclose CSR information.

Practical implications

The profitability is partially sourced from the synergy of IDs and stakeholders through CSR. IDs may use CSR disclosure to win stakeholders’ goodwill. This goodwill will likely be transformed into profitability. The empirical results indicate that there should be more need for IDs’ engagement in CSR projects as the resources of IDs combined with external stakeholders can be of important value to firms.

Originality/value

This paper reveals the underlying mechanism that firm-idiosyncratic value is formed using a combination of ID resources and stakeholders through CSR. This research extends the literature of IDs’ efficiency and effectiveness and confirms the agency theory and resource dependence theory.
Effect of transverse and parallel magnetic fields on thermal and thermo-hydraulic performances of ferro-nanofluid flow in trapezoidal microchannel heat sink
Authors: Sepehrnia Mojtaba , Khorasanizadeh Hossein , Shafii Mohammad Behshad
Published: May 2021

Purpose

This paper aims to study the thermal and thermo-hydraulic performances of ferro-nanofluid flow in a three-dimensional trapezoidal microchannel heat sink (TMCHS) under uniform heat flux and magnetic fields.

Design/methodology/approach

To investigate the effect of direction of Lorentz force the magnetic field has been applied: transversely in the x direction (Case I);transversely in the y direction (Case II); and parallel in the z direction (Case III). The three-dimensional governing equations with the associated boundary conditions for ferro-nanofluid flow and heat transfer have been solved by using an element-based finite volume method. The coupled algorithm has been used to solve the velocity and pressure fields. The convergence is reached when the accuracy of solutions attains 10–6 for the continuity and momentum equations and 10–9 for the energy equation.

Findings

According to thermal indicators the Case III has the best performance, but according to performance evaluation criterion (PEC) the Case II is the best. The simulation results show by increasing the Hartmann number from 0 to 12, there is an increase for PEC between 845.01% and 2997.39%, for thermal resistance between 155.91% and 262.35% and ratio of the maximum electronic chip temperature difference to heat flux between 155.16% and 289.59%. Also, the best thermo-hydraulic performance occurs at Hartmann number of 12, pressure drop of 10 kPa and volume fraction of 2%.

Research limitations/implications

The embedded electronic chip on the base plate generates heat flux of 60 kW/m2. Simulations have been performed for ferro-nanofluid with volume fractions of 1%, 2% and 3%, pressure drops of 10, 20 and 30 kPa and Hartmann numbers of 0, 3, 6, 9 and 12.

Practical implications

The authors obtained interesting results, which can be used as a design tool for magnetohydrodynamics micro pumps, microelectronic devices, micro heat exchanger and micro scale cooling systems.

Originality/value

Review of the literature indicated that there has been no study on the effects of magnetic field on thermal and thermo-hydraulic performances of ferro-nanofluid flow in a TMCHS, so far. In this three dimensional study, flow of ferro-nanofluid through a trapezoidal heat sink with five trapezoidal microchannels has been considered. In all of previous studies, in which the effect of magnetic field has been investigated, the magnetic field has been applied only in one direction. So as another innovation of the present research, the effect of applying magnetic field direction (transverse and parallel) on thermo-hydraulic behavior of TMCHS is investigated.
Sharing economy research in hospitality and tourism: a critical review using bibliometric analysis, content analysis and a quantitative systematic literature review
Authors: Mody Makarand Amrish , Hanks Lydia , Cheng Mingming
Published: May 2021

Purpose

This study aims to conduct a critical review of the research on the sharing economy to identify its key intellectual foundations and their evolution and offers thematic and methodological recommendations for future research to advance the domain.

Design/methodology/approach

A tri-method approach using bibliometric (co-citation) analysis, thematic content analysis and a quantitative systematic literature review was conducted on sharing economy research in hospitality and tourism journals, up to and including May 2020.

Findings

The findings from the three methods were coherent and provide a clear picture of the fact that while research on the sharing economy in hospitality and tourism has achieved significant depth, the breadth of the understanding of this area remains somewhat limited. Each of the three periods of research on the sharing economy identified in the study were marked by a focus on specific thematic areas, with largely Western-situated researchers demonstrating limited theoretical engagement and using a limited range of methods and perspectives (disciplinary, stakeholders and sectors) to examine these themes.

Research limitations/implications

Recommendations for future thematic research opportunities are provided using a multi-level perspective. The present review does not include research that incorporates the impacts of COVID-19, which has significantly disrupted the hospitality and tourism industry and is the focus of current research in the field. However, the review represents the largest and most comprehensive assessment of the state of research on the sharing economy prior to COVID-19, and, as such, can serve as a valuable baseline for future reviews of sharing economy research during and after the pandemic.

Originality/value

In contrast with previous literature reviews, the present review is comprehensive in its scope, methodology and temporal coverage of sharing economy research. It also examines the evolution of research on the topic, enabling a more nuanced identification of gaps and future thematic and methodological research opportunities.
Identifying and prioritizing barriers to digital transformation in higher education: a case study in Indonesia
Authors: Aditya Bayu Rima , Ferdiana Ridi , Kusumawardani Sri Suning
Published: May 2021

Purpose

This study aims to test a theoretical framework to identify and prioritize barriers in the implementation of digital transformation in higher education.

Design/methodology/approach

The framework was tested using the context of a particular nation: Indonesia. First, a survey questionnaire was conducted to identify the key barriers. Second, the contextual relationship between the key barriers was determined based on an expert’s input to find the importance level of barriers and the degree of difficulty to fix the barriers. Finally, a barrier priority matrix was developed to prioritize the barriers.

Findings

This study identified the key barriers in the implementation of digital transformation in higher education in Indonesia including eight contextual issues, one technical issue and two cultural issues with different levels of importance and difficulty. Based on the matrix constructed, this study also presented a list of the top 11 priorities of barriers.

Research limitations/implications

The results were based on a particular region context.

Practical implications

This study lays the foundation for the theoretical framework that is practically useful to perform the identification and prioritization of barriers. Besides, the result discussed in this study gives some direction for policymakers in designing sensible strategies to overcome the barriers.

Originality/value

The main contribution of this study is an empirical study that systematically identifies and prioritizes barriers to digital transformation in higher education.
Consumer xenocentrism and foreign goods purchase intention in an emerging economy
Authors: Mahmoud Mahmoud Abdulai , Mallen-Ntiador Tracy Nana Ebaskwa , Andoh Dominic , Iddrisu Mustapha , Kastner Adelaide Naa Amerley
Published: May 2021

Purpose

The purpose of this study is to test consumer xenocentric tendencies on foreign goods purchase intention and to examine the mediating role of cultural openness on the relationship.

Design/methodology/approach

A total number of 204 respondents participated in the study. Web-based sampling technique was employed to select a cross-section of consumers. Structural equation modelling technique of AMOS 21 version was used to test the nature of relationships in the research hypotheses.

Findings

The results suggest that except country image and interpersonal influence, all other constructs had a positive significant relationship with the intention to purchase. Country of origin, self-confidence and self-esteem had impact on consumer intention to purchase foreign products, though exposure of consumers to other cultures did not endear them to the products of those foreign markets.

Practical implications

From a managerial perspective, management awareness of xenocentrism tendencies is the surest way to make prudent decisions with respect to stocking and distributing foreign and local products or services.

Originality/value

The current study brings newness to the phenomenon as it tests consumer xenocentric (C-XEN) constructs in an emerging economy, and cultural openness as a mediating variable.
The effect of monetary incentives on task attractiveness, effort and performance
Authors: Robinson Michael , Farkas Maia
Published: May 2021

Purpose

There is a longstanding debate regarding the effectiveness of financial incentives in improving work performance. This study is motivated by seemingly conflicting theory and mixed research evidence, and advances the management accounting literature on pay-for-performance by examining the separate and joint effects of task attractiveness and monetary incentives on allocation of effort and on performance.

Design/methodology/approach

This study uses an online, multi-period, mixed design experiment with two independent groups of participants who receive either incentive pay or flat pay to perform a multidimensional job. The job tasks differ in complexity and participants can choose how to distribute effort between tasks. Observations are taken across two periods.

Findings

If the complex task is initially viewed as attractive it becomes less attractive over time, while the attractiveness of the simple task is stable. Participants who receive flat pay and who find the complex task attractive spent more time on working on that task than those compensated with incentives. Incentives caused higher initial performance than flat pay among participants who find the complex task to be attractive, but the differential is transient; dissatisfaction with initial performance seemingly contribute to a decline in attractiveness and deterioration in performance.

Research limitations/implications

The results indicate that task attributes and personal preferences moderate the effects of incentives on performance and that further research is needed to examine strategies to mitigate spillover effects of deficient performance to subsequent periods. However, the findings may not be applicable to extremely complex work environments involving numerous tasks and/or group work.

Practical implications

Showing that incentives may have a positive but transitory effect on performance, because task attributes and personal preferences moderate the incentive-performance relationship, may have practical implications for hiring, job design and compensation systems design.

Originality/value

This paper contributes to the literature on pay-for-performance by using a setting that better represents contemporary work environments than prior studies have and introduces choice over effort allocation. Additionally, we contribute to theory by showing that economics and psychology theories should be viewed as complements in investigating the intricate relationship between incentives and performance.