bluuebunny/crossref_metadata_2025 huggingface dataset:
Rqc1 and other yeast proteins containing highly positively charged sequences are not targets of the RQC complex
Authors: Barros Géssica C. , Requião Rodrigo D. , Carneiro Rodolfo L. , Masuda Claudio A. , Moreira Mariana H. , Rossetto Silvana , Domitrovic Tatiana , Palhano Fernando L.
Published: November 2019

Highly positively charged protein segments are known to result in poor translation efficiency. This effect is explained by ribosome stalling caused by electrostatic interactions between the nascent peptide and the negatively charged ribosome exit tunnel, leading to translation termination followed by protein degradation mediated by the RQC complex. These polybasic sequences are mainly studied in the context of artificial reporter systems. Examples of endogenous yeast proteins targeted by the RQC complex are Rqc1, a protein essential for RQC function, and Sdd1. Both contain polybasic sequences that are thought to activate the RQC, leading to protein down-regulation. Here, we investigated whether the RQC complex regulates other endogenous proteins with polybasic sequences. We show by bioinformatics, ribosome profiling data analysis, and western blot that endogenous proteins containing polybasic sequences similar to, or even more positively charged than those of Rqc1 and Sdd1, are not targeted by the RQC complex suggesting that endogenous polybasic sequences are not sufficient to induce this type of regulation. Finally, our results also suggest that Rqc1 is regulated post-translationally by the E3 component of the RQC complex Ltn1, in a manner independent of the RQC complex.
Complexin suppresses spontaneous exocytosis by capturing the membrane-proximal regions of VAMP2 and SNAP25
Authors: Malsam J. , Bärfuss S. , Trimbuch T. , Zarebidaki F. , Sonnen A.F.-P. , Wild K. , Scheutzow A. , Sinning I. , Briggs J.A.G. , Rosenmund C. , Söllner T.H.
Published: November 2019

The neuronal protein complexin contains multiple domains that exert both clamping and facilitatory functions to tune spontaneous and action potential triggered synaptic release. We address the clamping mechanism and show that the accessory helix of complexin arrests the assembly of the soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) complex that forms the core machinery of intracellular membrane fusion. In a reconstituted fusion assay, site- and stage-specific photo-cross-linking reveals that prior to fusion the complexin accessory helix laterally binds the membrane-proximal C-terminal ends of SNAP25 and VAMP2. Corresponding complexin interface mutants selectively increase spontaneous release of neurotransmitter in living neurons, implying that the accessory helix suppresses final zippering/assembly of the SNARE four-helix bundle by restraining VAMP2 and SNAP25.
GraphProt2: A graph neural network-based method for predicting binding sites of RNA-binding proteins
Authors: Uhl Michael , Tran Van Dinh , Heyl Florian , Backofen Rolf
Published: November 2019

CLIP-seq is the state-of-the-art technique to experimentally determine transcriptome-wide binding sites of RNA-binding proteins (RBPs). However, it relies on gene expression which can be highly variable between conditions, and thus cannot provide a complete picture of the RBP binding landscape. This creates a demand for computational methods to predict missing binding sites. Here we present GraphProt2, a computational RBP binding site prediction framework based on graph convolutional neural networks (GCNs). In contrast to current CNN methods, GraphProt2 offers native support for the encoding of base pair information as well as variable length input, providing increased flexibility and the prediction of nucleotide-wise RBP binding profiles. We demonstrate its superior performance compared to GraphProt and two CNN-based methods on single as well as combined CLIP-seq datasets. Conceived as an end-to-end method, GraphProt2 includes all necessary functionalities, from dataset generation over model training to the evaluation of binding preferences and binding site prediction. Various input types and features are supported, accompanied by comprehensive statistics and visualizations to inform the user about datatset characteristics and learned model properties. All this makes GraphProt2 the most versatile and complete RBP binding site prediction method available so far.
Rapid Quantification of Peptide Oxidation Isomers from Complex Mixtures
Authors: Khaje Niloofar Abolhasani , Sharp Joshua S.
Published: November 2019

Hydroxyl radical protein footprinting (HRPF) is a powerful technique for probing changes in protein topography, based on quantifying the amount of oxidation of different regions of a protein. While quantification of HRPF oxidation at the peptide level is relatively common, quantification at the residue level is challenging due to the influence of oxidation on MS/MS fragmentation and the large number of complex and only partially chromatographically resolved isomeric peptide oxidation products. HRPF quantification of isomeric peptide oxidation products (where the peptide sequence is the same but isomeric oxidation products are formed at different sites) at the residue level by electron transfer dissociation tandem mass spectrometry (ETD MS/MS) has been demonstrated in both model peptides and HRPF products, but the method is hampered by the partial separation of oxidation isomers by reversed phase chromatography. This requires custom MS/MS methods to equally sample all isomeric oxidation products across their elution window, greatly increasing method development time and reducing the oxidation products quantified in a single LC-MS/MS run. Here we present a zwitterionic hydrophilic interaction capillary chromatography (ZIC-HILIC) method to ideally co-elute all isomeric peptide oxidation products while separating different peptides. This allows us to relatively quantify peptide oxidation isomers using an ETD MS/MS spectrum acquired at any point across the single peptide oxidation isomer peak, greatly simplifying data acquisition and data analysis at both the peptide and amino acid level.
Neural Responses and Perceptual Sensitivity to Sound Depend on Sound-Level Statistics
Authors: Herrmann Björn , Augereau Thomas , Johnsrude Ingrid S.
Published: November 2019

Sensitivity to sound-level statistics is crucial for optimal perception, but research has focused mostly on neurophysiological recordings, whereas behavioral evidence is sparse. We use electroencephalography (EEG) and behavioral methods to investigate how sound-level statistics affect neural activity and the detection of near-threshold changes in sound amplitude. We presented noise bursts with sound levels drawn from distributions with either a low or a high modal sound level. One participant group listened to the stimulation while EEG was recorded (Experiment I). A second group performed a behavioral amplitude-modulation detection task (Experiment II). Neural activity depended on sound-level statistical context in two different ways. Consistent with an account positing that the sensitivity of neurons to sound intensity adapts to ambient sound level, responses for higher-intensity bursts were larger in low-mode than high-mode contexts, whereas responses for lower-intensity bursts did not differ between contexts. In contrast, a concurrent slow neural response indicated prediction-error processing: The response was larger for bursts at intensities that deviated from the predicted statistical context compared to those not deviating. Behavioral responses were consistent with prediction-error processing, but not with neural adaptation. Hence, neural activity adapts to sound-level statistics, but fine-tuning of perceptual sensitivity appears to involve neural prediction-error responses.
Differential activation of G-protein-mediated signalling by synthetic cannabinoid receptor agonists
Authors: Sachdev Shivani , Banister Samuel D. , Santiago Marina , Bladen Chris , Kassiou Michael , Connor Mark
Published: November 2019

Synthetic cannabinoid receptor agonists (SCRAs) are new psychoactive substances associated with acute intoxication and even death. However, the molecular mechanisms through which SCRAs may exert their toxic effects remain unclear - including the potential differential activation of G protein subtypes by CB1, a major target of SCRA. We measured CB1-mediated activation of Gαs and Gαi/o proteins by SCRAs by examining stimulation (PTX-treated) as well as inhibition (non-PTX treated) of forskolin-induced cAMP accumulation in HEK cells stably expressing CB1. Real-time measurements of stimulation and inhibition of cAMP levels were made using a BRET biosensor. We found that the maximum concentration of SCRAs tested (10 μM), increased cAMP levels 12 to 45% above that produced by forskolin alone, while the phytocannabinoid THC did not significantly alter cAMP levels in PTX-treated HEK-CB1 cells. All SCRAs had greater potency to inhibit of forskolin-induced cAMP levels than to stimulate cAMP levels. The rank order of potencies for SCRA stimulation of cAMP (Gαs) was PB-22 > 5F-MDMB-PICA > JWH-018 > AB-FUBINACA > XLR-11. By contrast, the potency of SCRAs for inhibition of cAMP (Gαi/o) was 5F-MDMB-PICA > AB-FUBINACA > PB-22 > JWH-018 > XLR-11. The different rank order of potency of the SCRAs to stimulate Gαs-like signalling compared to Gαi/o signalling suggests differences in G protein preference between SCRAs. Understanding the apparent differences among these drugs may contribute to unravelling their complex effects in humans.
Benchmark of tools for CNV detection from NGS panel data in a genetic diagnostics context
Authors: Moreno-Cabrera José Marcos , Valle Jesús del , Castellanos Elisabeth , Feliubadaló Lidia , Pineda Marta , Brunet Joan , Serra Eduard , Capellà Gabriel , Lázaro Conxi , Gel Bernat
Published: November 2019

Motivation

Although germline copy number variants (CNVs) are the genetic cause of multiple hereditary diseases, detecting them from targeted next-generation sequencing data (NGS) remains a challenge. Existing tools perform well for large CNVs but struggle with single and multi-exon alterations. The aim of this work is to evaluate CNV calling tools working on gene panel NGS data with CNVs up to single-exon resolution and their suitability as a screening step before orthogonal confirmation in genetic diagnostics strategies.

Results

Five tools (DECoN, CoNVaDING, panelcn.MOPS, ExomeDepth and CODEX2) were tested against four genetic diagnostics datasets (495 samples, 231 CNVs), using the default and sensitivity-optimized parameters. Most tools were highly sensitive and specific, but the performance was dataset-dependant. In our in-house datasets, DECoN and panelcn.MOPS with optimized parameters showed enough sensitivity to be used as screening methods in genetic diagnostics.

Availability

Benchmarking-optimization code is freely available athttps://github.com/TranslationalBioinformaticsIGTP/CNVbenchmarkeR.
Affinity of rhodopsin to raft enables the aligned oligomer formation from dimers: Coarse-grained molecular dynamics simulation of disk membranes
Authors: Kaneshige Yukito , Hayashi Fumio , Morigaki Kenichi , Tanimoto Yasushi , Yamashita Hayato , Fuji Masashi , Awazu Akinori
Published: November 2019

The visual photopigment protein rhodopsin (Rh) is a typical G protein-coupled receptor (GPCR) that initiates the phototransduction cascade in retinal disk membrane of rod-photoreceptor cells. Rh molecule has a tendency to form dimer, and the dimer tends to form rows, which is suggested to heighten phototransduction efficiency in single-photon regime. In addition, the dimerization confers Rh an affinity for lipid raft, i.e. raftophilicity. However, the mechanism by which Rh-dimer raftophilicity contributes to the organization of the higher order structure remains unknown. In this study, we performed coarse-grained molecular dynamics simulations of a disk membrane model containing unsaturated lipids, saturated lipids with cholesterol, and Rh-dimers. We described the Rh-dimers by two-dimensional particle populations where the palmitoyl moieties of each Rh exhibits raftophilicity. We simulated the structuring of Rh in a disk for two types of Rh-dimer, i.e., the most and second most stable Rh dimers, which exposes the raftophilic regions at the dimerization-interface (H1/H8 dimer) and two edges away from the interface (H4/H5 dimer), respectively. Our simulations revealed that only the H1/H8 dimer could form a row structure. A small number of raftophilic lipids recruited to and intercalated in a narrow space between H1/H8 dimers stabilize the side-by-side interaction between dimers in a row. Our results implicate that the nano-sized lipid raft domains act as a “glue” to organize the long row structures of Rh-dimers.
Cutting in-line with iron: ribosomal function and non-oxidative RNA cleavage
Authors: Guth-Metzler Rebecca , Bray Marcus S. , Frenkel-Pinter Moran , Suttapitugsakul Suttipong , Montllor-Albalate Claudia , Bowman Jessica C. , Wu Ronghu , Reddi Amit R. , Okafor C. Denise , Glass Jennifer B. , Williams Loren Dean
Published: November 2019

Divalent metal cations are essential to the structure and function of the ribosome. Previous characterizations of the ribosome performed under standard laboratory conditions have implicated Mg2+ as a primary mediator of ribosomal structure and function. Possible contributions of Fe2+ as a ribosomal cofactor have been largely overlooked, despite the ribosome’s early evolution in a high Fe2+ environment, and its continued use by obligate anaerobes inhabiting high Fe2+ niches. Here we show that (i) Fe2+ cleaves RNA by in-line cleavage, a non-oxidative mechanism that has not previously been shown experimentally for this metal, (ii) the first-order rate constant with respect to divalent cations is more than 200 times greater with Fe2+ than with Mg2+, (iii) functional ribosomes are associated with Fe2+ after purification from cells grown under low O2 and high Fe2+, and (iv) a small fraction of Fe2+ that is associated with the ribosome is not exchangeable with surrounding divalent cations, presumably because it is tightly coordinated by rRNA and buried in the ribosome. In total, these results expand the ancient role of iron in biochemistry and highlight a possible new mechanism of iron toxicity.

Key Points

Fe2+ cleaves rRNA by a non-oxidative in-line cleavage mechanism that is more than 200 times faster than in-line cleavage with Mg2+;

ribosomes purified from cells grown under low O2 and high Fe2+ retain ~10 Fe2+ ions per ribosome and produce as much protein as low O2, high Mg2+-grown ribosomes;

a small fraction (~2%) of Fe2+ that is associated with the ribosome is not exchangeable.
Increased efficacy of histone methyltransferase G9a inhibitors against MYCN-amplified Neuroblastoma
Authors: Bellamy Jacob , Szemes Marianna , Melegh Zsombor , Dallosso Anthony , Kollareddy Madhu , Catchpoole Daniel , Malik Karim
Published: November 2019

Targeted inhibition of proteins modulating epigenetic changes is an increasingly important priority in cancer therapeutics, and many small molecule inhibitors are currently being developed. In the case of neuroblastoma (NB), a paediatric solid tumour with a paucity of intragenic mutations, epigenetic deregulation may be especially important. In this study we validate the histone methyltransferase G9a/EHMT2 as being associated with indicators of poor prognosis in NB. Immunological analysis of G9a protein shows it to be more highly expressed in NB cell-lines with MYCN amplification, which is a primary determinant of dismal outcome in NB patients. Furthermore, G9a protein in primary tumours is expressed at higher levels in poorly differentiated/undifferentiated NB, and correlates with high EZH2 expression, a known co-operative oncoprotein in NB. Our functional analyses demonstrate that siRNA-mediated G9a depletion inhibits cell growth in all NB cell lines, but, strikingly, only triggers apoptosis in NB cells with MYCN amplification, suggesting a synthetic lethal relationship between G9a and MYCN. This pattern of sensitivity is also evident when using small molecule inhibitors of G9a, UNC0638 and UNC0642. The increased efficacy of G9a inhibition in the presence of MYCN-overexpression is also demonstrated in the SHEP-21N isogenic model with tet-regulatable MYCN. Finally, using RNA sequencing, we identify several potential tumour suppressor genes that are reactivated by G9a inhibition in NB, including the CLU, FLCN, AMHR2 and AKR1C1-3. Together, our study underlines the under-appreciated role of G9a in NB, especially in MYCN-amplified tumours.
The cell-wall-localised BETA-XYLOSIDASE 4 contributes to immunity of Arabidopsis against Botrytis cinerea
Authors: Guzha Athanas , McGee Robert , Hartken Denise , Scholz Patricia , Lüdke Daniel , Bauer Kornelia , Wenig Marion , Zienkiewicz Krzysztof , Feussner Ivo , Vlot A. Corina , Wiermer Marcel , Haughn George , Ischebeck Till
Published: November 2019

Plant cell walls constitute physical barriers that restrict access of microbial pathogens to the contents of plant cells. The primary cell wall of multicellular plants predominantly consists of cellulose, hemicellulose and pectin. In Arabidopsis, a cell wall-localised protein, BETA-XYLOSIDASE 4 (BXL4) that belongs to a seven-member BETA-XYLOSIDASE (BXL) gene family was induced upon infection with the necrotrophic fungal pathogen Botrytis cinerea and mechanical wounding in a jasmonoyl isoleucine (JA-Ile) dependent manner. Ectopic expression of the BXL4 gene in Arabidopsis seed coat epidermal cells was able to rescue a bxl1 mutant phenotype suggesting that like BXL1, BXL4, had both xylosidase and arabinosidase activity and acts in mura on cell wall polysaccharides. bxl4 mutants show a compromised resistance to B. cinerea. Upon infection, bxl4 mutants accumulated reduced levels of JA-Ile and camalexin. Conditional overexpression of BXL4 resulted in enhanced expression of PDF1.2 and PAD3 transcripts both before and after B. cinerea infection. This was associated with reduced susceptibility of the transgenic lines to B. cinerea. These data suggest that remodelling or degradation of one or more cell wall polysaccharides is important for plant immunity against B. cinerea and plays a role in pathogen-induced JA-Ile and camalexin accumulation.

One-sentence summary

BXL4 is a putative bifunctional xylosidase/arabinofuranisodase localising to the apoplast, important for immunity against the necrotrphic pathogen B. cinerea.
A whole-genome scan for association with invasion success in the fruit flyDrosophila suzukiiusing contrasts of allele frequencies corrected for population structure
Authors: Olazcuaga Laure , Loiseau Anne , Parrinello Hugues , Paris Mathilde , Fraimout Antoine , Guedot Christelle , Diepenbrock Lauren M. , Kenis Marc , Zhang Jinping , Chen Xiao , Borowieck Nicolas , Facon Benoit , Vogt Heidrun , Price Donald K. , Vogel Heiko , Prud’homme Benjamin , Estoup Arnaud , Gautier Mathieu
Published: November 2019

Evidence is accumulating that evolutionary changes are not only common during biological invasions but may also contribute directly to invasion success. The genomic basis of such changes is still largely unexplored. Yet, understanding the genomic response to invasion may help to predict the conditions under which invasiveness can be enhanced or suppressed. Here we characterized the genome response of the spotted wing drosophilaDrosophila suzukiiduring the worldwide invasion of this pest insect species, by conducting a genome-wide association study to identify genes involved in adaptive processes during invasion. Genomic data from 22 population samples were analyzed to detect genetic variants associated with the status (invasive versus native) of the sampled populations based on a newly developed statistic, we calledC2, that contrasts allele frequencies corrected for population structure. This new statistical framework has been implemented in an upgraded version of the program BayPass. We identified a relatively small set of single nucleotide polymorphisms (SNPs) that show a highly significant association with the invasive status of populations. In particular, two genesRhoGEF64Candcpo, the latter contributing to natural variation in several life-history traits (including diapause) inDrosophila melanogaster, contained SNPs significantly associated with the invasive status in the two separate main invasion routes ofD. suzukii. Our methodological approaches can be applied to any other invasive species, and more generally to any evolutionary model for species characterized by non-equilibrium demographic conditions for which binary covariables of interest can be defined at the population level.
Maternal exposure to cigarette smoking induces immediate and durable changes in placental DNA methylation affecting enhancer and imprinting control regions
Authors: Rousseaux Sophie , Seyve Emie , Chuffart Florent , Bourova-Flin Ekaterina , Benmerad Meriem , Charles Marie-Aline , Forhan Anne , Heude Barbara , Siroux Valérie , Slama Remy , Tost Jorg , Vaiman Daniel , Khochbin Saadi , Lepeule Johanna ,   the EDEN mother-child cohort study group
Published: November 2019

Objective

Exposure to cigarette smoking during pregnancy has been robustly associated with cord blood DNA methylation. However, little is known about such effects on the placenta; in particular, whether cigarette smoking before pregnancy could also induce epigenetic alterations in the placenta of former smokers is unknown.

Design and results

Placental DNA methylation levels were measured in 568 women and compared among non-smokers and women either smoking during their pregnancy or who had ceased smoking before pregnancy. An Epigenome Wide Association Study identified 344 Differentially Methylated Regions (DMRs) significantly associated with maternal smoking status. Among these 344 DMRs, 262 showed “reversible” alterations of DNA methylation, only present in the placenta of current smokers, whereas 44 were also found altered in former smokers, whose placenta had not been exposed directly to cigarette smoking. This observation was further supported by a significant demethylation of LINE-1 sequences in the placentas of both current (−0.43 (−0.83 to −0.02)) and former smokers (−0.55 (−1.02 to −0.08)) compared to nonsmokers. A comparative analysis of the epigenome landscape based on the ENCODE placenta data demonstrated an enrichment of all 344 DMRs in enhancers histone marks. Additionally, smoking-associated DMRs were found near and/or overlapping with 13 imprinting gene clusters encompassing 18 imprinted genes.

Conclusions

DNA methylation patterns alterations were found in 344 genomic regions in the placenta of women smoking during their pregnancy, including 44 DMRs and LINE-1 elements, where methylation changes persisted in former smokers, supporting the hypothesis of an “epigenetic memory” of exposure to cigarette smoking before pregnancy. Enhancers regions, including imprinting control regions were also particularly affected by placenta methylation changes associated to smoking, suggesting a biological basis for the sensitivity of these regions to tobacco exposure and mechanisms by which fetal development could be impacted.
The photochromic behaviour of two viologen salts modulated by the distances between the halide anions and the cationic N atoms of viologen
Authors: Zhang Yan , Li Mei , Li Shi-Li , Zhang Xian-Ming
Published: November 2019

In recent years, viologens and their derivatives have received much attention due to their various potential applications, ranging from electro- or photochromic devices to clean energy. Generally, viologen compounds exhibit a colour change upon being subjected to an external stimulus. However, the chromic mechanism is still ambiguous, because there are many electron-transfer pathways for a chromic compound that need to be considered. Thus, exploring new chromic viologen-based compounds with one pathway should be important and meaningful. In this article, two new viologen-based derivatives, namely 1-(2-cyanobenzyl)-4,4′-bipyridinium chloride (o-CBbpy·Cl), C18H14N3
+·Cl− (1), and 1-(2-cyanobenzyl)-4,4′-bipyridinium bromide (o-CBbpy·Br), C18H14N3
+·Br− (2), have been synthesized and characterized. Interestingly, both isomorphic compounds possess only one electron-transfer pathway, in which 1-(2-cyanobenzyl)-4,4′-bipyridinium cations (o-CBbpy) and halide anions are employed as electron donors and acceptors, respectively. Salts 1 and 2 consist of o-CBbpy cations involved in π–π interactions and hydrogen-bond interactions, and halide anions weakly hydrogen bonded to the viologen cations. The salts show different photoresponsive characteristics under identical conditions, which should be mainly related to the distances between the halide cations and the cationic N atoms of o-CBbpy but not the electronegativities of the halogen atoms. These results should not only help in understanding that the distance of the electron-transfer pathway plays an important role in viologen-based photochromism, but should also guide the design and synthesis of additional photochromic materials.
Like a conductor: whole-class discussion in English classrooms
Authors: Reynolds Todd
Published: November 2019

Purpose

After interviewing teachers about their beliefs on discussion, the author observed four English teachers as they led class discussions. The purpose of this study is to see what kinds of discussion were happening, and what teachers were doing to facilitate those discussions.

Design/methodology/approach

The author observed six English class sessions with discussion as a technique and transcribed each. To analyze the discussion events (DEs), the author focused on the addressivity of the teachers’ comments, and plotted the DEs on a four-quadrant system of analysis. The quadrants helped to move beyond the value-laden dichotomy between monologic and dialogic discussion, and to better understand what teachers are doing.

Findings

The majority of class sessions were classified as convergent-active but teachers used a variety of discussions. In particular, teachers were concerned about control, so they used three techniques to keep procedural control as follows: taking over the discussion, creating specific procedures and using the Initiation-Response-Evaluation format in different ways.

Originality/value

Instead of focusing on a dichotomy this method of analysis opens up the possibility for labeling different kinds of dialogic instruction, like the teacher-as-conductor form of convergent-active discussions. This can help teachers understand that addressivity and purpose matter as they create their discussions but also that various forms of discussion are necessary in the classroom. Incorporating dialogic instruction has been difficult for teachers; this method can help describe what they are doing while not devaluing the kinds of discussion that are taking place.
Emerging theory of teacher resilience: a situational analysis
Authors: Drew Sally Valentino , Sosnowski Cathy
Published: November 2019

Purpose

This study aims to explore the construct of teacher resilience. Researchers examined the relationship among complex risk (constraining) factors leading to burnout and attrition, as well as protective (enabling) factors that allow teachers to adapt and thrive within stressful school settings.

Design/methodology/approach

This paper presents results from three focus groups comprised of 33 English language arts teachers across diverse school districts. Utilizing situational analysis, developed from grounded theory, the research plan included six stages: development of initial situational map honoring theoretical sensitivity, theoretical sampling, data collection, coding, memoing, sorting, revising of the initial map based on analysis and literature review to develop the relational map.

Findings

Three propositions emerged beginning to comprise a theory of teacher resilience. (1) Resilient teachers embed roots in their school communities to withstand challenges, pulling from a sense of purpose to navigate constraining factors and benefit from enabling factors. (2) Resilient teachers embrace uncertainty, reframing negative experiences into learning experiences. Reframing helps teachers retain power, not cede it to situations, which helps balance constraining and enabling factors. (3) Teachers use relationships with colleagues, students and school leaders to endure challenges. The dynamic interaction between internal and external enabling and constraining factors is depicted on the situational map illustrating how factors counterbalance to either predict positive outcomes such as resilience and agency or negative outcomes such as burnout or attrition.

Originality/value

Despite a robust international evidence base, there is a dearth of US studies exploring teacher resilience. This study proposes a theory of teacher resilience relevant to US schools and recommends practical applications and future research.
Influence of transportation infrastructure on the relationship between institutions and economic performance
Authors: Wong Mei Chi , Yip Tsz Leung
Published: November 2019

Purpose

This study aims to analyse the observation that the economics of many countries have boomed after the input of substantial investments into physical and social infrastructures.

Design/methodology/approach

A structural equation model is formulated to examine the effect of transportation infrastructure on the relationship between institutions and gross domestic product per capita (GDPPC). This study further differentiates between developed and developing economies.

Findings

The study identifies the different roles of transportation infrastructure in mediating the relationship between institutions and average income in these two types of economy. Institutions and transportation infrastructure positively influence GDPPC, whereas institutions positively influence transportation infrastructure. In addition, the results found indirect influence of institutions on GDPPC via transportation infrastructure.

Originality/value

This study provides new insights into international business studies based on institutional theory and factor-mobility theory.
Understanding social media users’ unfollow intentions: take WeChat subscriptions as an example
Authors: Zhang Ge , Ma Liang , Zhang Xin , Ding Xiao Yan , Yang Yi Ping
Published: November 2019

Purpose

An increasing number of users join and become immersed in WeChat official accounts, but many users quit using these services as well. Nevertheless, most of the previous studies mainly focussed on the usage behavior. The purpose of this paper is to fill the gap by examining factors affecting users’ unfollow intentions for WeChat subscriptions in a Chinese context.

Design/methodology/approach

Structural equation modeling is used in our study. A field survey with 260 WeChat users is conducted to test the research model and hypotheses.

Findings

The results show the following interesting key findings: first, the effect of actual cost on users’ unfollow intentions is larger than the effect of opportunity cost; second, users’ unfollow intentions will decrease with the increase of users’ perceptions of information usefulness; third, the results of the control variables showed that only landing frequency has a negative effect on users’ unfollow intentions; and fourth, users’ demographic differences are also examined in regard to how they may affect users’ unfollow intentions.

Originality/value

First, this paper studies factors influencing users’ unfollow intentions for WeChat subscriptions from a social exchange theory perspective; the authors considered both extraneous factors and users’ internal perception factors potentially affecting users’ unfollow intentions, which has rarely been researched. Furthermore, the authors examined significant differences among users’ demographic characteristics in affecting users’ unfollow intentions. The results of the study provide a more comprehensive understanding of the influencing factors of users’ unfollow intentions.
Fostering sustainability and competitiveness in European tourism
Authors: Santander Eduardo
Published: November 2019

Purpose

This paper aims to explore sustainable tourism in Europe in economic, socio-cultural and environmental dimensions as well as discuss key challenges and necessary steps to be taken by the national tourism organisations.

Design/methodology/approach

The author takes a look at the evolution and importance of sustainable development for the travel and tourism industry today.

Findings

Last year Europe reached another record of international tourist arrivals, resulting in a 6 per cent increase on the previous year’s performance. Factors that contributed to this development include the recovery of major source markets, marketing efforts in promoting travel offseason as well as themed promotional activities in third markets. However, the European tourism industry is facing increasing challenges, in particular, those related to the quest between sustainable practices and the need for increasing competitiveness as a global destination.

Originality/value

This paper provides a current view of how sustainable tourism in Europe became a key global challenge.
Sustainability communication in hospitality in peripheral tourist destinations
Authors: Santos Margarida Custódio , Veiga Célia , Águas Paulo , Santos José António C.
Published: November 2019

Purpose

The purpose of this study posited that tourism companies and more especially hotels located in tourist destinations dependent on air transportation, need to commit more strongly to sustainability because of their greater distance from the main outbound markets. The research focused on determining whether hotels’ star rating, location, age and size influence their sustainability communication and on identifying the characteristics of the messages used in hotels’ sustainability communication.

Design/methodology/approach

To accomplish these objectives, a sequential mixed methods design with three interconnected phases was used, including quantitative data and content analysis.

Findings

Less than 10% of hotels located in a tourist destination strongly dependent on air transportation and peripheral to the main outbound markets actually communicate about sustainable practices on their websites. Communication practices are dependent on hotels’ star rating, location, size and age.

Research limitations/implications

The study limitations are that it was conducted in only one destination and that the hotel websites’ layouts are heterogeneous, which means that the analysis and comparison of the relevant information is extremely challenging. In addition, the research only considered hotels or similar lodgings, leaving out other types of accommodation.

Practical implications

Hotels in tourist destinations dependent on air transportation need to adjust their sustainability communication in response to the trend among tourists toward greater consciousness about the environmental impacts of their individual tourism-related choices. Hotels also need to provide more accurate and detailed information on sustainable practices, with both affective and rational appeals that focus on tourists’ experiences.

Originality/value

The study was conducted in a destination dependent on air transportation and peripheral to the primary outbound markets.
How much do rare and crop‐pollinating bees overlap in identity and flower preferences?
Authors: MacLeod Molly , Reilly James , Cariveau Daniel P. , Genung Mark A. , Roswell Michael , Gibbs Jason , Winfree Rachael
Published: November 2019

The biodiversity‐centred approach to conservation prioritizes rare species, whereas the ecosystem services approach prioritizes species that provide services to people. The two approaches align when rare species provide ecosystem services, or when both groups of species benefit from the same management action. We use data on bee pollinators and the plant species they forage on to determine if there are rare species among the most important crop pollinators, and the extent to which plant species selected to support crop pollinators would support rare species as well.

We used pre‐existing, regional‐scale datasets to determine which bee species are regionally rare, and which are regionally important crop pollinators. To assess the plant preferences of these two groups of bee species, we collected two datasets on plant–pollinator interactions, one experimental and one observational. The experiment consisted of monospecific plots of 17 plant species from which we collected bees over 3 years. The observational data consisted of bees collected from 66 species of plants growing in semi‐natural meadows, also over 3 years.

Nineteen percent of the dominant crop‐pollinating species were regionally rare. Both rare species and crop‐pollinating species had strong preferences for certain plants, and the preferences of rare and crop‐pollinating bees were significantly but not strongly (r ≤ .54) correlated. Ten plant species were significantly preferred by both rare and crop‐pollinating bees.

Synthesis and applications. We found several dominant crop pollinators that are rare at a regional scale, supporting the idea that rare species can be important providers of ecosystem services. The flower preferences of rare and crop‐pollinating bees are significantly positively associated, suggesting that plants chosen to support crop pollinators will benefit rare species as well. We identify plant species that are preferred by regionally rare bees and by crop pollinators, including 10 plant species preferred by both types of bees, and recommend these for use in pollinator habitat plantings.
Contribution of small isolated habitats in creating refuges from biological invasions along a geomorphological gradient of floodplain waterbodies
Authors: Ishiyama Nobuo , Miura Kazuki , Yamanaka Satoshi , Negishi Junjiro N. , Nakamura Futoshi
Published: November 2019

Habitat fragmentation, which involves habitat size reduction and isolation, is a major cause of biodiversity decline. However, interest in small isolated habitats has increased among ecosystem managers because these fragments can serve as remnant refuges for unique and/or endangered species in human‐altered landscapes.

In a fragmented floodplain of northern Japan, we demonstrate how habitat fragmentation and habitat quality shape the refuges for a unique endangered minnow Rhynchocypris percnurus sachalinensis from biological invasions. We focused on two invasive minnows, topmouth gudgeon Pseudorasbora parva and rosy bitterling Rhodeus ocellatus ocellatus, which are the dominant invasive species. By using a graph theoretical approach and structural equation modelling, we elucidated the relationships among habitat fragmentation, habitat quality and the abundance of invasive minnows with the endangered swamp minnow.

We found that the invasion of topmouth gudgeon, which has a high mobility and environmental tolerance, negatively affected swamp minnow populations. The invasive species may outcompete the native species in their overlapping trophic niche.

Analyses indicated that habitat fragmentation (decreasing habitat size and connectivity) indirectly and positively affected the population abundance of swamp minnow by reducing the potential for invasion by topmouth gudgeon. We further found an interaction between the indirect effects of habitat fragmentation and local habitat quality: the indirect effects became more apparent in the relatively deeper habitats that were of better quality for natives. This result was likely attributed to the strong control effect of the abiotic stressor. Interspecific competition between the two minnows would be masked in shallow ponds because the native populations are primarily restricted by the abiotic factor, and its abundance is inherently limited regardless of pressure by invaders.

Synthesis and applications. In fragmented landscapes, evenly conserving all small fragments within a limited budget is difficult. The change in importance of small isolated ponds across a pond‐depth gradient suggests that conservation priorities for small fragments should be established by considering local habitat quality. Our findings do not justify habitat fragmentation but suggest that both landscape‐scale and local‐scale perspectives synergistically aid in the management of biological invasions in modified habitat networks.
Host selection of hematophagous leeches (Haemadipsa japonica): Implications for iDNA studies
Authors: Hanya Goro , Morishima Kaori , Koide Tomoya , Otani Yosuke , Hongo Shun , Honda Takeaki , Okamura Hiroki , Higo Yuma , Hattori Masamichi , Kondo Yuki , Kurihara Yosuke , Jin Sakura , Otake Aji , Shiroisihi Izumi , Takakuwa Tomomi , Yamamoto Hiroki , Suzuki Hanami , Kajimura Hisashi , Hayakawa Takashi , Suzuki‐Hashido Nami , Nakano Takafumi
Published: November 2019

The development of an efficient and cost‐effective method for monitoring animal populations or biodiversity is urgently needed, and invertebrate‐derived DNA (iDNA) may offer a promising tool for assessing the diversity and other ecological information of vertebrates. We studied the host species of a hematophagous leech (Haemadipsa japonica) in Yakushima by genetic barcoding and compared the results with those for mammal composition revealed by camera trapping. We analyzed 119 samples using two sets of primers by Sanger sequencing and one set of primer by next generation sequencing. The proportion of the samples that were successfully sequenced and identified to at least one species was 11.8–24.3%, depending on the three different methods. In all of these three methods, most of the samples were identified as sika deer (18/20, 6/15 and 16/29) or human (2/20, 7/15 and 21/29). The nonhuman mammal host species composition was significantly different from that estimated by camera trapping. Sika deer was the main host, which may be related with their high abundance, large body size and terrestriality. Ten samples included DNA derived from multiple species of vertebrates. This may be due to the contamination of human DNA, but we also found DNA from deer, Japanese macaque and a frog in the same samples, suggesting the mixture of the two meals in the gut of the leech. Using H. japonica‐derived iDNA would not be suitable to make an inventory of species, but it may be useful to collect genetic information on the targeted species, due to their high host selectivity.
Migrant Age Profiles and Long‐Run Living Standards in Australia
Authors: Parr Nick , Guest Ross
Published: November 2019

The age profile of immigration to Australia can be altered by public policies. This article applies a method of valuing long term population paths in order to evaluate alternative immigrant age profiles based on a proxy indicator of living standards over time for Australia. Results show that the variation in value of the population path follows an inverted U‐shape by immigrant's age. The strength of preference between immigrants aged 20–29 years and older working age immigrants reduces as the social discount rate increases. Higher life expectancy and lower fertility accentuate preference for younger working age immigrants.
Cost of chronic inflammatory disease: The impact of eosinophilic esophagitis in Nevada
Authors: Anderson Julia , Moonie Sheniz , Hogan Mary Beth , Scherr Rebecca , Labus Brian , Word Jessica
Published: November 2019

Objectives

The cost of treating the rare eosinophilic esophagitis (EoE) disease and its impact on patients’ quality of life have not been well documented in the literature. This study seeks to fill this gap by comparing the cost of EoE with other well‐known inflammatory diseases, including Crohn's disease (CD) and celiac disease (CeD).

Methods

A Mann‐Whitney U test and multiple logistic regression were used to examine the cost of EoE in the state of Nevada across all hospital settings and its impact on quality of life compared with CD and CeD.

Results

Several factors were associated with the overall cost of EoE in Nevada, including patients’ age, sex and region (P < 0.001). EoE was significantly more expensive to treat in the pediatric group ($4001 EoE; $985 CD; $856 CeD), among men ($2532 EoE; $1500 CD; $1724 CeD), among those residing in the southern region of Nevada ($4501 EoE; $2538 CD; $1888 CeD), and among patients seeking medical care from outpatient clinics ($3298 EoE; $741 CD; $1686 CeD) (P < 0.001). Age, sex, region and hospital setting were all associated with having a positive EoE record compared with CeD or CD (P < 0.001).

Conclusions

Data from this study indicate that the EoE burden is significantly higher in cost for certain demographics and regions compared with CD and CeD in the state of Nevada, specifically among pediatric and male patients. These differences suggest that clinicians may encounter similar issues when treating EoE.
Bacillus Calmette–Guérin immunotherapy for bladder cancer: a review of immunological aspects, clinical effects and BCG infections
Authors: Larsen Emilie Stavnsbjerg , Joensen Ulla Nordström , Poulsen Alicia Martin , Goletti Delia , Johansen Isik Somuncu
Published: November 2019

Bacillus Calmette–Guérin (BCG) immunotherapy for bladder cancer has been used since 1976 when the first evidence of its ability to lower recurrence and progression rates was published. Today, BCG immunotherapy is the choice of care for high‐grade non‐muscle invasive bladder cancer (NMIBC) after transurethral resection. This article presents indications and procedure of BCG instillations, and outlines the effects on recurrence and progression of NMIBC. The BCG‐induced immunity in NMIBC is not yet fully understood. Animal studies point towards BCG inducing specific tumour immunity. We describe the current knowledge of how this immunity is induced, from internalization of BCG bacilli in urothelial cells, to cytokine‐ and chemokine‐mediated recruitment of neutrophils, monocytes, macrophages, T cells, B cells and natural killer cells. In addition, we describe the process of trained immunity, the non‐specific protective effects of BCG. Recent studies also indicate that dysbiosis of the urinary microbiome may cause lower urinary tract dysfunction. Side effects of BCG bladder instillations range from common, mild and transient symptoms, such as dysuria and flu‐like symptoms, to more severe and rarely occurring life‐threatening complications. We review the literature and give an overview of reported incidences and management of BCG infections after intravesical instillation.