bluuebunny/crossref_metadata_2025 huggingface dataset:
Dissociable Cellular and Genetic Mechanisms of Cortical Thinning at Different Life Stages
Authors: Modabbernia Amirhossein , Vidal-Pineiro Didac , Agartz Ingrid , Andreassen Ole A , Ayesa-Arriola Rosa , Bertolino Alessandro , Boomsma Dorret I , Bourque Josiane , Breier Alan , Brodaty Henry , Brouwer Rachel M , Buitelaar Jan K , Canales-Rodríguez Erick J , Caseras Xavier , Conrod Patricia J , Crespo-Facorro Benedicto , Crivello Fabrice , Crone Eveline A , de Zubicaray Greig I , Dickie Erin W , Dima Danai , Frenzel Stefan , Fisher Simon E , Franke Barbara , Glahn David C , Grabe Hans-Jörgen , Grotegerd Dominik , Gruber Oliver , Guerrero-Pedraza Amalia , Gur Raquel E , Gur Ruben C , Hartman Catharina A , Hoekstra Pieter J , Hulshoff Pol Hilleke E , Jahanshad Neda , Jernigan Terry L , Jiang Jiyang , Kalnin Andrew J , Kochan Nicole A , Mazoyer Bernard , McDonald Brenna C , McMahon Katie L , Nyberg Lars , Oosterlaan Jaap , Pomarol-Clotet Edith , Radua Joaquim , Sachdev Perminder S , Satterthwaite Theodore D , Salvador Raymond , Sarro Salvador , Saykin Andrew J , Schumann Gunter , Smoller Jordan W , Sommer Iris E , Espeseth Thomas , Thomopoulos Sophia I , Trollor Julian N , van ‘t Ent Dennis , Voineskos Aristotle , Wang Yang , Weber Bernd , Westlye Lars T , Whalley Heather C , Williams Steven CR , Wittfeld Katharina , Wright Margaret J , Thompson Paul M , Paus Thomas , Frangou Sophia
Published: March 2022

Mechanisms underpinning age-related variations in cortical thickness in the human brain remain poorly understood. We investigated whether inter-regional age-related variations in cortical thinning (in a multicohort neuroimaging dataset from the ENIGMA Lifespan Working Group totalling 14,248 individuals, aged 4-89 years) depended on cell-specific marker gene expression levels. We found differences amidst early-life (<20 years), mid-life (20-60 years), and late-life (>60 years) in the patterns of association between inter-regional profiles of cortical thickness and expression profiles of marker genes for CA1 and S1 pyramidal cells, astrocytes, and microglia. Gene ontology and enrichment analyses indicated that each of the three life-stages was associated with different biological processes and cellular components: synaptic modeling in early life, neurotransmission in mid-life, and neurodegeneration in late-life. These findings provide mechanistic insights into age-related cortical thinning during typical development and aging.
Physoxia influences global and gene-specific methylation in pluripotent stem cells
Authors: Dogan Fatma , Al Jumaily Rakad M Kh , Kitchen Mark , Forsyth Nicholas R
Published: March 2022

Pluripotent stem cells (PSC) possess unlimited proliferation, self-renewal, and a differentiation capacity spanning all germ layers. Appropriate culture conditions are important for the maintenance of self-renewal, pluripotency, proliferation, differentiation, and epigenetic states. Oxygen concentrations vary across different human tissues depending on precise cell location and proximity to vascularisation. The bulk of PSC culture-based research is performed in a physiologically hyperoxic, air oxygen (21% O2) environment, with numerous reports now detailing the impact of physiologic normoxia (physoxia) low oxygen culture in the maintenance of stemness, survival, morphology, proliferation, differentiation potential, and epigenetic profiles. Epigenetic mechanisms affect multiple cellular characteristics including gene expression during development and cell fate determination in differentiated cells. We hypothesized that epigenetic marks are responsive to a reduced oxygen microenvironment in PSCs and their differentiation progeny. Here, we evaluated the role of physoxia in PSC culture, the regulation of DNA methylation (5mC and 5hmC), and expression of regulatory enzymes DNMTs and TETs. Physoxia enhanced the functional profile of PSC including proliferation, metabolic activity, and stemness attributes. PSCs cultured in physoxia revealed significant downregulation of DNMT3B, DNMT3L, TET1, and TET3 vs. air oxygen, accompanied by significantly reduced 5mC and 5hmC levels. Downregulation of DNMT3B was associated with an increase in its promoter methylation. Coupled to above we also noted decreased HIF1A but increased HIF2A expression in physoxia cultured PSCs, versus air oxygen. In conclusion, PSCs display oxygen-sensitive methylation patterns that correlate with transcriptional and translational regulation of the de novo methylase DNMT3B.
Polypyrimidine Tract-Binding Protein 1 (PTBP1) regulates CD4 T cell Activation independent of its role in proliferation
Authors: Narayanan Bitha , De Maio Diego Prado , LaPorta James , Voskoboynik Yekaterina , Matus-Nicodemos Rodrigo , Summers Sean , Ganapathi Usha , Valentin-Acevedo Anibal , Covey Lori R.
Published: March 2022

Our previous work found that the RNA binding protein polypyrimidine tract-binding protein (PTBP1) is critical for regulating multiple events in T cell activation including changes in proliferation, and expression of activation markers and cytokines. These changes corresponded to the regulation of the ERK1/2 and NF-κB pathways as well as through changes in steady-state RNA levels. Because proliferation is critical for driving T cell activation, it was unclear whether PTBP1 was required for optimal activationper seor whether changes were secondary to a requirement for initiating/sustaining proliferation. To address this question, the human T cell lymphoma cell line, Jurkat, which recapitulates many of the molecular events of TCR-induced activation, was used to understand how PTBP1 impacts early events in T cell activation with ongoing proliferation. Using two phenotypically distinct Jurkat subclones (D1.1 and B2.7), we first profiled global RNA expression patterns using RNAseq analysis and found marked differences between the two cell lines with the D1.1 line giving a more antigen-experienced phenotype. Reducing PTBP1 by shPTB expression, to 60% WT levels resulted in no significant decrease in proliferation in the two subclones. However, we observed that PTBP1 was required for both optimal expression of activation markers, CD25, CD38, CD69, and CD40L, and signaling through the ERK1/2, P38 and AKT pathways. Importantly, limiting PTBP1 had different effects on the activation signals for each cell line suggesting that the differentiation state of the cell is a critical factor in understanding the role of PTBP1 in T cell activation. This was further reinforced by our finding that PTBP1 regulated distinct groups of genes specific for each line. Together, our findings suggest that PTBP1 regulates specific T cell activation responses independent of its role in proliferation and that the initial phenotype of the T cell plays an essential role in the dependency of the cell on PTBP1 for driving these changes.
Leveraging shared ancestral variation to detect local introgression
Authors: Fang Lesly Lopez , Vecchyo Diego Ortega-Del , McTavish Emily Jane , Huerta-Sanchez Emilia
Published: March 2022

Introgression is a common evolutionary phenomenon that results in shared genetic material across non-sister taxa. Existing statistical methods such as Patterson’s D statistic can detect introgression by measuring an excess of shared derived alleles between populations. The D statistic is effective to detect genome-wide patterns of introgression but can give spurious inferences of introgression when applied to local regions. We propose a new statistic, D+, that leverages both shared ancestral and derived alleles to infer local introgressed regions. Incorporating both shared derived and ancestral alleles increases the number of informative sites per region, improving our ability to identify local introgression. We use a coalescent framework to derive the expected value of this statistic as a function of different demographic parameters under an instantaneous admixture model and use coalescent simulations to compute the power and precision of D+. While the power of D and D+ is comparable, D+ has better precision than D. We apply D+ to empirical data from the 1000 Genome Project and Heliconius butterflies to infer local targets of introgression in humans and in butterflies.
Identification of a Novel Osteogenetic Oligodeoxynucleotide (osteoDN) that Promotes Osteoblast Differentiation in a TLR9-Independent Manner
Authors: Nihashi Yuma , Miyoshi Mana , Umezawa Koji , Shimosato Takeshi , Takaya Tomohide
Published: March 2022

Recent studies have revealed that oligodeoxynucleotides (ODNs) designed from genome sequences have the potential to regulate cell fate. Currently, ODNs that conduct cell differentiation are nanomolecular drug candidates for regenerative medicine. Herein, we demonstrate that iSN40, an 18-base ODN derived from theLacticaseibacillus rhamnosusGG genome, promoted the differentiation and calcification of osteoblasts that play a central role during bone formation. In the murine osteoblast cell line MC3T3-E1, iSN40 enhanced alkaline phosphatase activity at the early stage of differentiation and facilitated calcium deposition at the late stage by inducing the expression of osteogenic genes such as Msx2, osterix, collagen type 1α, osteopontin, and osteocalcin. Intriguingly, the CpG motif within iSN40 was not required for its osteogenetic activity, indicating that iSN40 functions in a TLR9-independent manner. These data suggest that iSN40, serving as an osteogenetic ODN (osteoDN), as a drug seed that target osteoblasts for bone regeneration.
Basal and stress-induced expression changes consistent with water loss reduction explain desiccation tolerance of natural Drosophila melanogaster populations
Authors: Horváth Vivien , Guirao-Rico Sara , Salces-Ortiz Judit , Rech Gabriel E. , Green Llewellyn , Aprea Eugenio , Rodeghiero Mirco , Anfora Gianfranco , González Josefa
Published: March 2022

Background

Climate change is one of the main factors shaping the distribution and biodiversity of organisms, among others by greatly altering water availability, thus exposing species and ecosystems to harsh desiccation conditions. Insects are especially threatened by these challenging dry environments, because of their small size and thus large surface area to volume ratio. Integrating transcriptomics and physiology is key to advancing our knowledge on how species cope with desiccation stress, and these studies are still best accomplished in model organisms.

Results

Here, we characterized the natural variation of European D. melanogaster populations across climate zones and found that strains from arid regions were similar or more tolerant to desiccation compared with strains from temperate regions. Tolerant and sensitive strains differed not only in their transcriptomic response to stress but also in their basal expression levels. We further showed that gene expression changes in tolerant strains correlated with their physiological response to desiccation stress and with their cuticular hydrocarbon composition. Transposable elements, which are known to influence stress response across organisms, were not found to be enriched nearby differentially expressed genes. Finally, we identified several tRNA-derived small RNA fragments that differentially targeted genes in response to desiccation stress.

Conclusions

Our results showed that by integrating transcriptomics with physiological trait analysis we can pinpoint the genetic basis of the differences in tolerance to desiccation stress found in natural D. melanogaster populations. Moreover, we showed that, beyond starvation and aging, tRNA-derived small RNA fragments (tRFs) appear to be relevant post-transcriptional gene regulators in response to desiccation stress.
The little skate genome and the evolutionary emergence of wing-like fin appendages
Authors: Marletaz Ferdinand , de la Calle-Mustienes Elisa , Acemel Rafael D. , Nakamura Tetsuya , Paliou Christina , Naranjo Silvia , Martinez-Garcia Pedro M. , Cases Ildefonso , Sleight Victoria A. , Hirschberger Christine , Marcet-Houben Marina , Navon Dina , Andrescavage Ali , Skvortsova Ksenia , Duckett Paul E. , Gonzalez-Rajal Alvaro , Bogdanovic Ozren , Gibcus Johan H. , Yang Liyan , Gallardo-Fuentes Lourdes , Sospedra Ismael , Lopez-Rios Javier , Darbellay Fabrice , Visel Axel , Dekker Job , Shubin Neil , Gabaldon Toni , Tena Juan J. , Lupianez Dario G. , Rokhsar Daniel S. , Gomez-Skarmeta Jose L.
Published: March 2022

Skates are cartilaginous fish whose novel body plan features remarkably enlarged wing-like pectoral fins that allow them to thrive in benthic environments. The molecular underpinnings of this unique trait, however, remain elusive. Here we investigate the origin of this phenotypic innovation by developing the little skate Leucoraja erinacea as a genomically enabled model. Analysis of a high-quality chromosome-scale genome sequence for the little skate shows that it preserves many ancestral jawed vertebrate features compared with other sequenced genomes, including numerous ancient microchromosomes. Combining genome comparisons with extensive regulatory datasets in developing fins (gene expression, chromatin occupancy and three-dimensional (3D) conformation) we find skate-specific genomic rearrangements that alter the 3D regulatory landscape of genes involved in the planar cell polarity (PCP) pathway. Functional inhibition of PCP signaling resulted in marked reduction of anterior fin size, confirming this pathway as a major contributor of batoid fin morphology. We also identified a fin-specific enhancer that interacts with 3' HOX genes, consistent with the redeployment of Hox gene expression in anterior pectoral fins, and confirmed the potential of this element to activate transcription in the anterior fin using zebrafish reporter assays. Our findings underscore the central role of genome reorganizations and regulatory variation in the evolution of phenotypes, shedding light on the molecular origin of an enigmatic trait.
Solvent-induced allosteric transition of the Hepatitis C virus human cellular receptor CD81 large extracellular loop
Authors: Risueño C. , Charro D. , Abrescia N. G. A. , Coluzza I.
Published: March 2022

CD81 is a tetraspanin receptor that clusters into microdomains to mediate cell signalling processes. CD81 is also one of the four primary cellular receptors of the Hepatitis C virus (HCV). Previous structural studies on the α-helical CD81 large-extracellular-loop domain (CD81LEL) have shown that it can adopt different conformations (from closed to open), likely depending on the environmental conditions. This conformational plasticity has been implicated in the endosomal fusion of HCV upon entry. However, the precise mechanism governing the CD81LEL plasticity has remained elusive so far.

Here, by combining molecular dynamics simulations and circular dichroism experiments on wt-CD81LEL and two mutants at different endosomal pH conditions, pH 5.5 and pH 4.6, we show that the modulation of the solvation shell governs the plasticity of CD81LEL. The primarily implicated residues are D139 and E188, respectively, located near a loop preceded by a helix. At acidic conditions, their interaction with water is reduced, causing a re-ordering of the water molecules, and thus triggering the dynamics of CD81LEL. However, mutations E188Q and D139N retain the solvation shell and restrict the conformational space that the head subdomain can explore.

We propose that residues E188 and D139 control the solvent-induced allosteric transition of the CD81LEL domain. This mechanism might play a role in other cellular receptors that function along the endosomal pathway.

Popular Summary

Understanding the cellular mechanisms that are exploited by viruses to infect their host is key for the development of therapeutics. Here, in the context of Hepatitis C Virus infection we report the mechanism that governs the plasticity of the extra-cellular domain of tetraspanin CD81, one of the major cellular receptors of this virus. The mechanism proposed here is a novel form of solvent-induced allosteric transition in proteins mediated by two antenna residues located in the head subdomain of CD81. We propose that it could serve as a pH sensing strategy to time the endosomal pathway and trigger a signal at the right time for HCV fusion.
Implicit Versus Explicit Timing – Separate or Shared Mechanisms?
Authors: Herbst Sophie K , Obleser Jonas , van Wassenhove Virginie
Published: March 2022

Abstract

Time implicitly shapes cognition, but time is also explicitly represented, for instance in the form of durations. Parsimoniously, the brain could use the same mechanisms for implicit and explicit timing. Yet, the evidence has been equivocal, revealing both joint versus separate signatures of timing. Here, we directly compared implicit and explicit timing using magnetoencephalography, whose temporal resolution allows investigating the different stages of the timing processes. Implicit temporal predictability was induced in an auditory paradigm by a manipulation of the foreperiod. Participants received two consecutive task instructions: discriminate pitch (indirect measure of implicit timing) or duration (direct measure of explicit timing). The results show that the human brain efficiently extracts implicit temporal statistics of sensory environments, to enhance the behavioral and neural responses to auditory stimuli, but that those temporal predictions did not improve explicit timing. In both tasks, attentional orienting in time during predictive foreperiods was indexed by an increase in alpha power over visual and parietal areas. Furthermore, pre-target induced beta power in sensorimotor and parietal areas increased during implicit compared to explicit timing, in line with the suggested role for beta oscillations in temporal prediction. Interestingly, no distinct neural dynamics emerged when participants explicitly paid attention to time, compared to implicit timing. Our work thus indicates that implicit timing shapes the behavioral and sensory response in an automatic way, and is reflected in oscillatory neural dynamics, while the translation of implicit temporal statistics to explicit durations remains somewhat inconclusive, possibly due to the more abstract nature of this task.
Recruitment of clathrin to intracellular membranes is sufficient for vesicle formation
Authors: Küey Cansu , Sittewelle Méghane , Larocque Gabrielle , Hernández-González Miguel , Royle Stephen J
Published: March 2022

The formation of a clathrin-coated vesicle is a major membrane remodeling process that is crucial for membrane traffic in cells. Besides clathrin, these vesicles contain at least 100 different proteins although it is unclear how many are essential for the formation of the vesicle. Here, we show that intracellular clathrin-coated formation can be induced in living cells using minimal machinery and that it can be achieved on various membranes, including the mitochondrial outer membrane. Chemical heterodimerization was used to inducibly attach a clathrin-binding fragment "hook" to an "anchor" protein targeted to a specific membrane. Endogenous clathrin assembled to form coated pits on the mitochondria, termed MitoPits, within seconds of induction. MitoPits are double-membraned invaginations that form preferentially on high curvature regions of the mitochondrion. Upon induction, all stages of CCV formation - initiation, invagination, and even fission - were faithfully reconstituted. We found no evidence for the functional involvement of accessory proteins in this process. In addition, fission of MitoPit-derived vesicles was independent of known scission factors including dynamins and dynamin-related protein 1 (Drp1), suggesting that the clathrin cage generates sufficient force to bud intracellular vesicles. Our results suggest that, following its recruitment, clathrin alone is sufficient for intracellular clathrin-coated vesicle formation.
Mechanisms underlying the reprogramming of mouse embryonic fibroblasts to thymic epithelial cells
Authors: Ma Zhongyao , Kang Seung Woo , Condie Brian G. , Manley Nancy R.
Published: March 2022

Thymic epithelial cells (TECs) are a critical functional component of the thymus’s ability to generate T cells for the adaptive immune system in vertebrates. However, no in vitro system for studying TEC function exists. Overexpression of the transcription factor FOXN1 initiates reprogramming of fibroblasts into TEC-like cells (iTECs) that support T cell differentiation in culture or after transplant. In this study, we characterized iTEC reprogramming at the cellular and molecular level to determine how reprogramming proceeds and identify mechanisms that can be targeted for improving this process. These data show that iTEC reprogramming consists of discrete gene expression changes that differ in early and late reprogramming, and that iTECs upregulate markers of both cortical and medullary TEC (cTEC and mTEC) lineages, although mTEC differentiation is blocked at a progenitor stage. We demonstrate that promoting proliferation enhances iTEC generation, and that Notch inhibition allows induction of mTEC differentiation. Finally, we show that a major difference between iTEC and fetal TEC is the expression of MHCII. This study supports future efforts to improve iTEC reprogramming for both research and translational uses.
Genomic insights into the evolutionary relationships and demographic history of kiwi
Authors: Westbury Michael V , De Cahsan Binia , Shepherd Lara D , Holdaway Richard N , Duchene David A , Lorenzen Eline D
Published: March 2022

Kiwi are a unique and emblematic group of birds endemic to New Zealand. Deep-time evolutionary relationships among the five extant kiwi species have been difficult to resolve, in part due to the absence of pre-Quaternary fossils to inform speciation events among them. Here, we utilise single representative nuclear genomes of all extant kiwi species (great spotted kiwi, little spotted kiwi, Okarito brown kiwi, North Island brown kiwi, and southern brown kiwi) and investigate their evolutionary histories with phylogenomic, genetic diversity, and deep-time (past million years) demographic analyses. We uncover low levels of gene-tree phylogenetic discordance across the genomes, suggesting clear distinction between species. However, we also find indications of post-divergence gene flow, concordant with recent reports of interspecific hybrids. The four species with available reference assemblies show relatively low levels of genetic diversity, which we suggest reflects a combination of older environmental as well as more recent anthropogenic influence. In addition, we uncover similarities and differences in the demographic histories of the five kiwi species over the past million years, and suggest hypotheses regarding the impact of known past environmental events, such as volcanic eruptions and glacial periods, on the evolutionary history of the group.
{N′-[(E)-1-(5-Chloro-2-oxidophenyl)ethylidene]-4-methoxybenzohydrazidato-κ3
O,N′,O′}(1H-imidazole-κN
3)nickel(II)
Authors: Chang Jian-Guo
Published: March 2022

In the title complex, [Ni(C16H13ClN2O3)(C3H4N2)], the NiII ion is coordinated by two O atoms and one N atom derived from the dianionic N′-[(1E)-1-(5-chloro-2-hydroxyphenyl)ethylidene]-4-methoxybenzohydrazide ligand and one N atom from the imidazole molecule. The N2O2 donor set defines an approximate square-planar geometry. The dihedral angles between the imidazole ring and the fused six-membered and methoxybenzene rings are 17.78 (14) and 13.23 (16)°, respectively; the dihedral angle between the C6 rings is 6.63 (12)°. The most prominent feature of the molecular packing is the formation of 41-helical chains (along the c axis) mediated by imidazole-N—H...O(phenoxide) hydrogen bonding; these are linked by methyl-C—H...Cl interactions.
Psychologists’ views on the accessibility and effectiveness of psychological therapies for people with intellectual disabilities and autism
Authors: Siddell Poppy
Published: March 2022

Purpose

The purpose of this study was to explore the views of psychologists working in community teams for people who have intellectual disabilities (ID) on the provision of psychological therapies to those with ID and autism spectrum disorder (ASD).

Design/methodology/approach

Semi-structured interviews were carried out with seven clinical psychologists working across a large geographical area. Interviews concerned the accessibility and effectiveness of psychological therapies. These were transcribed and analysed thematically.

Findings

Participants expressed concern about lack of access to mainstream services, the lack of visibility of their service and the suitability of the physical space to deliver therapy. They were positive about the effectiveness of therapy but emphasised the importance of adaptations and managing expectations.

Research limitations/implications

There is a lack of research in this area, and further research is needed with service users to develop a fuller understanding of their needs.

Practical implications

Consideration needs to be given on how to optimally deliver psychological therapies for this group. This will need services to become more flexible and focussed on the needs of this group of service users.

Originality/value

This paper provides insights into the views of psychologists on providing psychological therapy to people who have autism and ID.
Business analytics: an example of integration of TD-ABC and the balanced scorecard
Authors: Nielsen Steen
Published: March 2022

Purpose

The purpose of this paper is twofold. First, to combine a holistic model – in our case the balanced scorecard – with the time-driven activity-based costing model. The inspiration for this stems both from Kaplan and Norton and from the intense discussions and use of business analytics (BA) and performance management (PM). Second, to use numerical experiments – more specifically Monte Carlo simulation – to design and explore four hypothetical scenarios within such a holistic model. The paper also aims to emphasise the role played by statistics in increasing the confidence in using such a framework.

Design/methodology/approach

The author runs four numerical experiments using different assumptions to show how a decision-maker can improve the outcome by making small changes in the key performance indicator (KPI) input variables.

Findings

The paper gives recommendations for the assumptions that each decision-maker has to consider when setting out to conduct this kind of analysis. Small changes in some input variables may completely change the output and hence the decision result.

Practical implications

The paper shows why practitioners and researchers need to better understand the limitations of deterministic analysis to make realistic models when combining more accounting models. To choose the relevant probability distributions for the input resources is an important issue for the decision-maker as they have a very large impact on the result.

Originality/value

The real value of the paper lies in making students and practitioners as well as researchers aware of the opportunities for stochastic modelling and also to point at the problems and limitations of combining elements from BA with performance measurement and management.
Bubble detection in Bitcoin and Ethereum and its relationship with volatility regimes
Authors: Diniz Renan , Prince Diogo de , Maciel Leandro
Published: March 2022

Purpose

The aim of this paper is to test the existence of bubbles for the daily prices of cryptocurrencies Bitcoin and Ethereum and verify if there is a relationship between bubbles and volatility regimes.

Design/methodology/approach

The authors test the presence of bubbles with the generalized supremum augmented Dickey–Fuller (GSADF) test using critical values simulated by the bootstrap procedures of Gutierrez (2011), Harvey et al. (2016) and Pedersen and Schütte (2020). Also, the authors estimate Markov regime switching generalized autoregressive conditional heteroskedasticity model for these cryptocurrencies.

Findings

The GSADF test result indicates the presence of bubbles for both cryptocurrencies. Simulating critical values by wild-bootstrap, which is robust to non-stationary volatility, leads to the highest number of bubbles in both cryptocurrencies. In addition, based on the estimates of conditional variance models with regime changes, the authors find that the bubbles identified are associated with a regime of low returns volatility, indicating a change in the trade-off between risk and return when the prices of cryptocurrencies differ from their fundamental values.

Originality/value

To the best of the authors knowledge, there are no studies that test the explosive behavior for cryptocurrencies by the GSADF test using the bootstrap method to simulate critical values from the procedures of Harvey et al. (2016) or Pedersen and Schütte (2020). These bootstrapping procedures are robust to heteroscedasticity and avoid the detection of false bubbles. Further, the advantage of Harvey et al. (2016) procedure is the robustness to non-stationary volatility.
How do low-status expatriates deal with crises? Stress, external support and personal coping strategies during the COVID-19 pandemic
Authors: Haist Joshua , Kurth Philipp
Published: March 2022

Purpose

Low-status expatriates (LSEs), a highly vulnerable group, have been significantly affected by the ongoing COVID-19 pandemic. This study explores the stressors that continue to impact LSEs in Germany and their access to support during the pandemic.

Design/methodology/approach

An interpretivist, qualitative research approach was employed. The authors utilised a multi-level data collection strategy that combined interview and questionnaire data from 16 expatriates and 16 social actors. The data were analysed using a directed content analysis method.

Findings

LSEs experienced high levels of stress that were further exacerbated by the introduction of COVID-19 control measures that were intended to slow the spread of the virus. LSEs are particularly vulnerable due to their overrepresentation in precarious professions and the associated job insecurity. Critically, external support from employers and social actors is generally lacking, leaving LSEs to rely on their own personal coping strategies in difficult times.

Research limitations/implications

The earlier Expatriate crisis Framework highlights the importance of external support for expatriates. However, this framework does not sufficiently account for personal coping strategies that are particularly important for individuals that cannot access such external support (e.g. LSEs). Herein, the authors offer a revised framework that is more applicable to LSEs.

Practical implications

Current practices are problematic, necessitating policy changes at both governmental and organisational levels.

Originality/value

This study provides unique insights into the ways in which the pandemic has affected the already precarious position of LSEs and identifies the importance of personal coping strategies in the absence of external sources of support.
Impact of institutional voids on the performance of small and medium-sized enterprises
Authors: Saha Krishnendu , Malesios Chrisovaladis , Chowdhury Soumyadeb , Dey Prasanta Kumar
Published: March 2022

Purpose

There is a critical gap in assessing how institutional voids affect SMEs' growth, investment commitment and reputation. The purpose of this paper is to explain how institutional void affects these three dimensions of SME performance; and to develop an institutional void-SME performance framework that can be applied for strategising, resourcing and competency acquisition for better performance.

Design/methodology/approach

The study used the Enterprise Survey Data of the World Bank, consisting of 118,763 firms from 140 countries. The structural equation modelling (SEM) is used to analyse the data, validate our analytical model and investigate the imposed theoretical claims of causality as indicated by specific research questions through correlation/covariation between the constructs of institutional void and SME performance.

Findings

Evidence suggests that there is a strong positive correlation between formal institutional infrastructure (independent variable) and SMEs' reputation (dependent variable). Among the institutional sub-constructs, tax administration, business licensing and permits, access to a bigger market and skilled labour and informal competition are significant for the SME performance constructs. We find similar results while comparing SMEs with large businesses.

Practical implications

The institutional void-SME performance framework developed from our findings will allow SMEs to manage institutional voids affecting their performance. The analytical framework can also be the foundation for future empirical research.

Originality/value

The originality of the study is embedded in its investigation of SMEs' investment commitment and reputation in relation to institutional voids. The latent relationship between the sub-constructs of institutional voids and SME performance adds new knowledge to the dynamic relationship between institutions and firm performance.
Adaptation strategies employed by rural women in the face of climate change impacts in Vhembe district, Limpopo province, South Africa
Authors: Nyahunda Louis , Tirivangasi Happy Mathew
Published: March 2022

Purpose

This study documented adaptation strategies employed by rural women in Vhembe district as they reel with climate change impacts. Women are heavily plagued by climate change impacts than any other genders worldwide. This is attributed to their high dependence on the natural resources for survival, low adaptive capacity, illiteracy, social ascribed roles that limit their participation in climate change initiatives like men and high poverty levels. Despite the daunting fact of women's vulnerability to climate change and its vagary impacts, women are agents of social change who have not remained passive victims to climate change and its impacts.

Design/methodology/approach

This study adopted a qualitative methodology guided by multi-case study design. A sample of 25 participants was selected through simple random and purposive sampling techniques. Data were collected using Focus Group Discussions and individual interviews and analysed thematically. Rural women and traditional leaders served as key informants and participated in the study.

Findings

The study established that the effects of climate change on rural women are real; however, there is a cocktail of strategies employed by women in Vhembe district in response to these effects. The strategies include livelihood and crop diversification, use of indigenous knowledge systems and harnessing of social capital among other household-based adaptation strategies.

Originality/value

The study recommends that the best way of assisting rural women in adapting to climate change is through the amelioration of poverty, enhancing capacity building for women and elimination of all systems that serve as barriers to effective adaptation.
Latin American female academic perceptions about the COVID pandemic’s impact on gender equity and within-country inequality
Authors: Ramirez Lozano Julianna Paola , Bridshaw Araya Leslie Cecilia , Brito Ochoa María Paulina
Published: March 2022

Purpose

The pandemic caused by COVID-19 has brought us a serious economic, health and social problem worldwide crisis. In this context, there has been an increase in inequality between men and women throughout the world. In this situation of home confinement, uncertainty, stress and fear, women have been the most affected, regardless of their education level. The purpose of this study is to know the impact on the perception of academic women who suffered from a lack of gender equality (sustainable development) during the pandemic (SDG 5) and, therefore, the increase in the gender inequality gap (SDG 10) in Latin America (LA).

Design/methodology/approach

This qualitative, exploratory-descriptive study has a nonexperimental field and cross-sectional design that uses the field technique of focus groups.

Findings

This study revealed the deepest feelings of women researchers on this issue, leading to a deep reflection on the need to build the basis to transform unequal gender relations and introduce the gender perspective in a cross-sectional manner in a university context.

Originality/value

This study, analyzed from a gender perspective, aimed to unravel the complexity in which the majority of LA women academics live and to explain the gaps and differences in their lives caused by the inequalities that have increased due to the pandemic in Latin American societies.
Effects of trust in organizations and trait mindfulness on optimism and perceived stress of flight attendants during the COVID-19 pandemic
Authors: Suthatorn Pornprom , Charoensukmongkol Peerayuth
Published: March 2022

Purpose

This research adopts the conservation of resources (COR) theory to examine the effects of trust in organizations and trait mindfulness on optimism and perceived stress of flight attendants in Thailand during the COVID-19 pandemic.

Design/methodology/approach

Online survey data were collected from 234 flight attendants who work for five low-cost airlines based in Thailand. The data were analyzed by using partial least squares structural equation modeling (PLS-SEM).

Findings

The results show that trust in an organization and trait mindfulness are negatively associated with the perceived stress of flight attendants. Their associations are also partially mediated by optimism. Moreover, the moderating effect analysis reveals that trait mindfulness intensifies the positive association between trust in organizations and optimism.

Originality/value

The evidence from this research broadens COR theory by showing that different aspects of resources can be combined to strengthen the ability of individuals to gain more resources to lessen stress.
A systemic approach for implementing AI methods in education during COVID-19 pandemic: higher education in Saudi Arabia
Authors: Sayed Al Mnhrawi Dalia Nabil Tawfiq Al , Alreshidi Hamad A.
Published: March 2022

Purpose

The outbreak of COVID-19 has projected prominent threats to the learning and teaching environment. The context of pandemic has delivered numerous advices, which are relevant in dealing with the pandemic situation, to the educational institution administrators, educators and other officials.

Design/methodology/approach

The response of an educational body addresses the needs as well as the concerns of learners and their parents. Educational body incorporates asynchronous learning methodologies that work pre-eminent in digital media, to enhance their ability to teach distantly. To make remote teaching and learning efficient, artificial intelligence (AI) approaches are incorporated into the traditional system of education.

Findings

Educational body have to encompass a diversified tools and system that places COVID-19 in a worldwide, in addition to the general disciplines of classroom. AI and other technological advancement has introduced numerous tools and applications for handling the pandemic situation.

Originality/value

This research discussed the impact of COVID and influence of AI on education and also the significance and applications of AI in education system in Saudi Arabia. In addition, this study examined the experience of Saudi’s students Universities with AI applications, (316) form the sample of this study to response it’s the Likert scale tool. The results of the study indicated that in the midst of the COVID-19 outbreak, the Government switched to online education, and positive responses were found from learners with taking all benefits of AI application. However, the lack of experience played a critical role in preventing full utilization of AI applications, which will motivate the decision maker to train the learner and the teacher to take advantage of these applications to face any pandemic in future.
Longitudinal prevalence of atopic dermatitis among freshmen at Hiroshima University between 2002 and 2019
Authors: Kan Takanobu , Tanaka Akio , Kanamoto Mayu , Morioke Satoshi , Takahagi Shunsuke , Hide Michihiro
Published: March 2022

The prevalence of atopic dermatitis (AD) has been steadily increasing in recent decades, reaching a steady plateau at the end of the 20th century. However, most of them were surveys of children, and the current prevalence and severity of AD in adults are unknown. A longitudinal survey including 40 649 freshmen attending Hiroshima University between 2002 and 2019 was conducted, with the aim to determine changes in AD prevalence in young adults over the age of 18 years. All data were longitudinally collected at a fixed time of the year. The AD diagnosis and severity assessment were made by dermatologists based on the diagnostic criteria in the Japanese Guidelines for AD. History or comorbidities of asthma and allergic rhinitis/conjunctivitis, current AD management, and use of topical corticosteroids (TCS) were also surveyed using a questionnaire. The prevalence of AD in university freshmen is slightly increasing from 9.1% in 2002 to 12.0% in 2010, remaining steady at around 10–11% until 2019, with poorly controlled AD present in nearly 10%. History or comorbidities of asthma and allergic rhinitis/conjunctivitis slightly increased from 2006 to 2019 in both the students with and without AD. Facial eczema was common among those with severe and most severe AD, whereas approximately 50% of the students with moderate AD and approximately 20% of those with mild AD exhibited facial eczema. The percentage of students treating AD at medical institutions and those self‐managing was almost the same. This survey also revealed the presence of substantial anxiety regarding TCS use for AD and the necessity of promoting more effective explanation and education on AD by medical professionals.
Disentangle genus microdiversity within a complex microbial community by using a multi‐distance long‐read binning method: example of Candidatus Accumulibacter
Authors: Adler Aline , Poirier Simon , Pagni Marco , Maillard Julien , Holliger Christof
Published: March 2022

Complete genomes can be recovered from metagenomes by assembling and binning DNA sequences into metagenome assembled genomes (MAGs). Yet, the presence of microdiversity can hamper the assembly and binning processes, possibly yielding chimeric, highly fragmented and incomplete genomes. Here, the metagenomes of four samples of aerobic granular sludge bioreactors containing Candidatus (Ca.) Accumulibacter, a phosphate‐accumulating organism of interest for wastewater treatment, were sequenced with both PacBio and Illumina. Different strategies of genome assembly and binning were investigated, including published protocols and a binning procedure adapted to the binning of long contigs (MuLoBiSC). Multiple criteria were considered to select the best strategy for Ca. Accumulibacter, whose multiple strains in every sample represent a challenging microdiversity. In this case, the best strategy relies on long‐read only assembly and a custom binning procedure including MuLoBiSC in metaWRAP. Several high‐quality Ca. Accumulibacter MAGs, including a novel species, were obtained independently from different samples. Comparative genomic analysis showed that MAGs retrieved in different samples harbour genomic rearrangements in addition to accumulation of point mutations. The microdiversity of Ca. Accumulibacter, likely driven by mobile genetic elements, causes major difficulties in recovering MAGs, but it is also a hallmark of the panmictic lifestyle of these bacteria.
The secret life of plant‐beneficial rhizosphere bacteria: insects as alternative hosts
Authors: Pronk Lotte J. U. , Bakker Peter A. H. M. , Keel Christoph , Maurhofer Monika , Flury Pascale
Published: March 2022

Root‐colonizing bacteria have been intensively investigated for their intimate relationship with plants and their manifold plant‐beneficial activities. They can inhibit growth and activity of pathogens or induce defence responses. In recent years, evidence has emerged that several plant‐beneficial rhizosphere bacteria do not only associate with plants but also with insects. Their relationships with insects range from pathogenic to mutualistic and some rhizobacteria can use insects as vectors for dispersal to new host plants. Thus, the interactions of these bacteria with their environment are even more complex than previously thought and can extend far beyond the rhizosphere. The discovery of this secret life of rhizobacteria represents an exciting new field of research that should link the fields of plant–microbe and insect–microbe interactions. In this review, we provide examples of plant‐beneficial rhizosphere bacteria that use insects as alternative hosts, and of potentially rhizosphere‐competent insect symbionts. We discuss the bacterial traits that may enable a host‐switch between plants and insects and further set the multi‐host lifestyle of rhizobacteria into an evolutionary and ecological context. Finally, we identify important open research questions and discuss perspectives on the use of these rhizobacteria in agriculture.
A Mixed Methods Evaluation of Interventions to Meet the Requirements of California Senate Bill 1152 in the Emergency Departments of a Public Hospital System
Authors: TAIRA BREENA R. , KIM HYUNG , PRODIGUE KARLA TLATELPA , GUTIERREZ‐PALOMINOS LEILANI , ALEMAN ALEXIS , STEINBERG LEORA , TCHAKALIAN GREGORY , YADAV KABIR , TUCKER‐SEELEY REGINALD
Published: March 2022

Policy Points

Clarifications to Senate Bill (SB) 1152 are necessary to address the differences between inpatient and emergency department (ED) discharge processes, determine how frequently an ED must deliver the SB 1152 bundle of services to a single patient, and establish expectations for compliance during off‐hours when social services are unavailable.

Because homelessness cannot be resolved in a single ED visit, the state should provide funding to support housing‐focused case workers that will follow patients experiencing homelessness (PEH) through the transition from temporary shelters to permanent supportive housing. Medi‐Cal could fund the delivery of the SB 1152 bundle of services to defray the costs to public hospitals that provide care for high numbers of PEH.

California legislators should consider complementary legislation to increase funding for shelters so that sufficient capacity is available to accept PEH from EDs and hospitals, and to fund alternative strategies to prevent poverty and the upstream root causes of homelessness itself.

Context

Prompted by stories of “patient dumping,” California enacted Senate Bill (SB) 1152, which mandates that hospitals offer patients experiencing homelessness (PEH) a set of resources at discharge to ensure safety and prevent dumping.

Methods

To evaluate interventions to meet the requirements of SB 1152 across three emergency departments (EDs) of a Los Angeles County public hospital system with a combined annual census of 260,000 visits, we used an explanatory sequential mixed methods approach, focusing first on quantitative evaluation and then using information from qualitative interviews to explain the quantitative findings.

Findings

In total, 2.9% (1,515/52,607) of encounters involved PEH. Documentation of compliance with the eight required components of SB 1152 was low, ranging from 9.0% to 33.9%. Twenty‐five provider interviews confirmed support for providing assistance to PEH in the ED, but the participants described barriers to compliance, including challenges in implementing universal screening for homelessness, incongruity of the requirements with the ED setting, the complexity of the patients, and the limitations of SB 1152 as a health policy.

Conclusions

Despite operationalizing universal screening for homelessness, we found poor compliance with SB 1152 and identified multiple barriers to implementation.