bluuebunny/crossref_metadata_2025 huggingface dataset:
Four novel Caudoviricetes bacteriophages isolated from Baltic Sea water infect colonizers of Aurelia aurita
Authors: Stante Melissa , Weiland-Braeuer Nancy , Repnik Urska , Werner Almut , Chibani Cynthia Maria , Bramkamp Marc , Schmitz Ruth A.
Published: June 2023

The moon jellyfish Aurelia aurita is associated with a highly diverse microbiota changing with provenance, tissue, and life stage. While the crucial relevance of bacteria to host fitness is well known, bacteriophages have often been neglected. Here, we aimed to isolate lytic phages targeting bacteria that are part of the A. aurita-associated microbiota. Four phages (Pseudomonas phage BSwM KMM1, Citrobacter phages BSwM KMM2- BSwM KMM4) were isolated from the Baltic Sea water column and characterized. Phages KMM2/3/4 infected representatives of Citrobacter, Shigella, and Escherichia (Enterobacteriaceae), whereas KMM1 showed a remarkably broad host range, infecting Gram-negative Pseudomonas as well as Gram-positive Staphylococcus. All phages showed short latent periods (around 30 min), large burst sizes (mean of 128 pfu/mL), and high efficiency of plating (EOP > 0.5), demonstrating decent virulence, efficiency, and infectivity. Transmission electron microscopy and viral genome analysis revealed that all phages are novel species and belong to the tailed, linear double-stranded DNA phage families Siphovirus (KMM3) and Myovirus (KMM1/2/4), with genome sizes between 50 - 138 kbp. Those isolates now allow manipulation of the A. aurita-associated microbiota and will provide new insights into phage impact on the multicellular host.
Molecular determinants of avoidance and inhibition ofPseudomonas aeruginosaMexB efflux pump
Authors: Gervasoni Silvia , Mehla Jitender , Bergen Charles , Leus Inga V. , Margiotta Enrico , Malloci Giuliano , Bosin Andrea , Vargiu Attilio V. , Lomovskaya Olga , Rybenkov Valentin V. , Ruggerone Paolo , Zgurskaya Helen I.
Published: June 2023

Transporters of the Resistance-Nodulation-cell Division (RND) superfamily of proteins are the dominant multidrug efflux power of Gram-negative bacteria. The major RND efflux pump ofPseudomonas aeruginosais MexAB-OprM, in which the inner membrane transporter MexB is responsible for recognition and binding of compounds. The high importance of this pump in clinical antibiotic resistance made it a subject of intense investigations and a promising target for the discovery of efflux pump inhibitors. This study is focused on a series of peptidomimetic compounds developed as effective inhibitors of MexAB-OprM. Previous analyses of antibacterial and biochemical activities showed that these compounds vary broadly in their efficiency as inhibitors or substrates of MexAB and can be categorized into different functional classes. Here, we performed multi-copy molecular dynamics simulations, machine learning analyses and site-directed mutagenesis of MexB to investigate interactions of MexB with representatives of the various classes. The analysis of both direct and water-mediated protein-ligand interactions revealed characteristic patterns for each class, highlighting significant differences between them. We found that efflux avoiders poorly interact with the access binding site of MexB, and inhibition engages amino acid residues that are not directly involved in binding and transport of substrates. In agreement, machine learning models selected different residues predictive of MexB substrates and inhibitors. The differences in interactions were further validated by site-directed mutagenesis. We conclude that the substrate translocation and inhibition pathways of MexB split at the interface (between the main putative binding sites) and at the deep binding pocket, and that interactions outside of the hydrophobic patch contribute to the inhibition of MexB. This molecular-level information could help in the rational design of new inhibitors and antibiotics less susceptible to the efflux mechanism.

Importance

Multidrug transporters recognize and expel from cells a broad range of ligands including their own inhibitors. The difference between the substrate translocation and inhibition routes remains unclear. In this study, machine learning, computational and experimental approaches were used to understand dynamics of MexB interactions with its ligands. Our results show that some ligands engage a certain combination of polar and charged residues in MexB binding sites to be effectively expelled into the exit funnel, whereas others engage aromatic and hydrophobic residues that slow down or hinder the next step in the transporter cycle. These findings suggest that all MexB ligands fit into this substrate-inhibitor spectrum depending on their physico-chemical structures and properties.
Dominant negative effects on H3K27 methylation by Weaver syndrome-associated EZH2 variants
Authors: Deevy Orla , Monger Craig , Matrà Francesca , Tuck Ellen , Conway Eric , Badonyi Mihaly , Nimmo Darragh , Rodighiero Simona , Zhang Qi , Davidovich Chen , Marsh Joseph A. , Pasini Diego , Bracken Adrian P.
Published: June 2023

Heterozygous missense mutations inEZH2cause Weaver syndrome (WS), a developmental disorder characterized by intellectual disability and overgrowth.EZH2encodes the enzymatic subunit of Polycomb Repressive Complex 2 (PRC2), which mediates mono-, di-, and tri-methylation of histone H3 lysine residue 27 (H3K27me1/2/3). Although the functional characterization of most WS-associated EZH2 variants is lacking, they are presumed loss of function. However, the dearth of reported early truncating mutations inEZH2led us to hypothesise that a dominant negative mutational mechanism may underlie the development of WS. To test this, we performed a detailed structural analysis of all known WS-associated EZH2 variants, which provided initial support that they are dominant negative. Next, we isogenically modelled 10 representative WS-associated EZH2 variants in embryonic stem cells and showed they induce global reductions in H3K27me2 and H3K27me3 with concomitant global increases in H3K27me1, H3K27ac, and chromatin decompaction. Importantly, the reductions in H3K27me2/3 methylation revealed a pattern of dominant-negative interference to PRC2 activity. Comparative analysis of a gain-of-function EZH2 variant causing growth restriction highlighted the reciprocal nature of the chromatin changes in these opposing growth syndromes. Our findings detail the molecular effects of developmental-syndrome-associated EZH2 variants in cells and implicate imbalanced landscapes of H3K27 modification in their pathology.
Phage anti-CBASS protein simultaneously sequesters cyclic trinucleotides and dinucleotides
Authors: Cao Xueli , Xiao Yu , Huiting Erin , Cao Xujun , Li Dong , Ren Jie , Guan Linlin , Wang Yu , Li Lingyin , Bondy-Denomy Joseph , Feng Yue
Published: June 2023

CBASS is a common anti-phage immune system that uses cyclic oligonucleotide signals to activate effectors and limit phage replication. In turn, phages encode anti-CBASS (Acb) proteins. We recently uncovered a widespread phage anti-CBASS protein Acb2 that acts as a “sponge” by forming a hexamer complex with three cGAMP molecules. Here, we identified that Acb2 binds and sequesters many CBASS and cGAS-produced cyclic dinucleotidesin vitroand inhibits cGAMP-mediated STING activity in human cells. Surprisingly, Acb2 also binds CBASS cyclic trinucleotides 3’3’3’-cyclic AMP-AMP-AMP (cA3) and 3’3’3’-cAAG with high affinity. Structural characterization identified a distinct binding pocket within the Acb2 hexamer that binds two cyclic trinucleotide molecules and another binding pocket that binds to cyclic dinucleotides. Binding in one pocket does not allosterically alter the other, such that one Acb2 hexamer can simultaneously bind two cyclic trinucleotides and three cyclic dinucleotides. Phage-encoded Acb2 provides protection from Type III-C CBASS that uses cA3 signaling moleculesin vivoand blocks cA3-mediated activation of the endonuclease effectorin vitro. Altogether, Acb2 sequesters nearly all known CBASS signaling molecules through two distinct binding pockets and therefore serves as a broad-spectrum inhibitor of cGAS-based immunity.
Exoribonuclease RNase R protects AntarcticPseudomonas syringaeLz4W from DNA damage and oxidative stress
Authors: Mittal Pragya , Sipani Rashmi , Pandiyan Apuratha , Sulthana Shaheen , Sinha Anurag K , Hussain Ashaq , Ray Malay K , Pavankumar Theetha L
Published: June 2023

RNase R is a highly processive, 3’ -5’ exoribonuclease involved in RNA degradation, maturation, and processing in bacteria. InPseudomonas syringaeLz4W, RNase R interacts with RNase E to form the RNA degradosome complex and is essential for growth at low temperature. RNase R is also implicated in general stress response in many bacteria. We show here that the deletion mutant ofrnrgene (encoding RNase R) ofP. syringaeis highly sensitive to various DNA damaging agents and oxidative stress. RNase R is a multidomain protein comprised of CSD, RNB and S1 domains. We investigated the role of each domain of RNase R and its exoribonuclease activity in nucleic acid damage and oxidative stress response. Our results revealed that the RNB domain alone without its exoribonuclease activity is sufficient to protect against DNA damage and oxidative stress. We also show that the association of RNase R with the degradosome complex is not required for this function. Our study has discovered for the first time a hitherto unknown role of RNase R in protectingP. syringaeLz4W against DNA damage and oxidative stress.

Importance

Bacterial exoribonucleases play a crucial role in RNA maturation, degradation, quality control and turnover. In this study, we have uncovered a previously unknown role of 3’-5’ exoribonuclease RNase R ofP. syringaeLz4W in DNA damage and oxidative stress response. Here, we show that neither the exoribonuclease function of RNase R, nor its association with the RNA degradosome complex is essential for this function. Interestingly, inP. syringaeLz4W, hydrolytic RNase R exhibits physiological roles similar to phosphorolytic 3’-5’ exoribonuclease PNPase ofE. coli. Our data suggest that during the course of evolution, mesophilicE. coliand psychrotrophicP. syringaehave apparently swapped these exoribonucleases to adapt to their respective environmental growth conditions.
The virulence regulator VirB fromShigella flexneriuses a CTP-dependent switch mechanism to activate gene expression
Authors: Jakob Sara , Steinchen Wieland , Hanßmann Juri , Rosum Julia , Osorio-Valeriano Manuel , Giammarinaro Pietro I. , Bange Gert , Thanbichler Martin
Published: June 2023

The transcriptional antisilencer VirB acts as a master regulator of virulence gene expression in the human pathogenShigella flexneri. It binds defined sequences (virS) upstream of VirB-dependent promoters and counteracts their silencing by the nucleoid-organizing protein H-NS. However, its precise mode of action remains unclear. Notably, VirB is not a classical transcription factor but related to DNA partitioning proteins of the ParB family, which have recently been recognized as DNA-sliding clamps using CTP binding and hydrolysis to control their DNA entry gate. Here, we show that VirB binds CTP, embraces DNA in a clamp-like fashion upon its CTP-dependent loading atvirSsites and slides laterally on DNA after clamp closure. Mutations that prevent CTP binding block the loading of VirB clamps invitroand the formation of VirB nucleoprotein complexesin vivo. Thus, VirB represents a CTP-dependent molecular switch that uses a loading-and-sliding mechanism to control transcription during bacterial pathogenesis.
Spatial Organization of Gas Vesicles is Governed by Phase-separable GvpU
Authors: Li Zongru , Shen Qionghua , Dai Yifan , Anderson Andrew P. , Iburg Manuel , Lin Richard , Zimmer Brandon , Meyer Matthew D. , You Lingchong , Chilkoti Ashutosh , Lu George J.
Published: June 2023

Gas vesicles (GVs) are microbial protein organelles that support cellular buoyancy, and the recent engineering of GVs has led to multiple applications including reporter gene imaging, acoustic control, and payload delivery. GVs often cluster into a honeycomb pattern to minimize their occupancy of cytosolic space; however, the molecular mechanism behind this process and its influence on cellular physiology remain unknown. Here, we identified GvpU as the protein governing this process. GvpU-mediated clustering is selective to the genotype of GVs, allowing the design of GV variants with genetically encodable clustering states. Furthermore, we uncovered that the clustering is modulated by phase transition behaviors encoded in the intrinsically disordered region of GvpU through a balanced contribution of acidic and aromatic residues, and such phase transition can directly modulate cellular fitness. Collectively, our findings elucidate the protein player, molecular mechanism, and functional roles of GV clustering, and its programmability for biomedical applications.
Structure and activation of the human autophagy-initiating ULK1C:PI3KC3-C1 supercomplex
Authors: Chen Minghao , Nguyen Thanh N. , Ren Xuefeng , Khuu Grace , Cook Annan S. I. , Zhao Yuanchang , Yildiz Ahmet , Lazarou Michael , Hurley James H.
Published: June 2023

The unc-51-like kinase protein kinase complex (ULK1C) is the most upstream and central player in the initiation of macroautophagy in mammals. Here, the cryo-EM structure of the human ULK1C core was determined at amino acid residue-level resolution. A moderate resolution structure of the ULK1C core in complex with another autophagy core complex, the class III phosphatidylinositol 3-kinase complex I (PI3KC3-C1) was also determined. The two complexes co-assemble through extensive contacts between the FIP200 scaffold subunit of ULK1C and the VPS15, ATG14, and BECN1 subunits of PI3KC3-C1.

The FIP200:ATG13:ULK1 core of ULK1C undergoes a rearrangement from 2:1:1 to 2:2:2 stoichiometry in the presence of PI3KC3-C1. This suggests a structural mechanism for the initiation of autophagy through formation of a ULK1C:PI3KC3-C1 supercomplex and dimerization of ULK1 on the FIP200 scaffold.
Pore-forming activity ofS. pneumoniaepneumolysin disrupts the paracellular localization of the epithelial adherens junction protein E-cadherin
Authors: Xu Shuying , MO DEVONS , Rizvi Fatima Z. , Rosa Juan , Ruiz Jorge , Tan Shumin , Tweten Rodney K , Leong John M , Adams Walter
Published: June 2023

Streptococcus pneumoniae, a common cause of community-acquired bacterial pneumonia, can cross the respiratory epithelial barrier to cause lethal septicemia and meningitis. S. pneumoniae pore-forming toxin pneumolysin (PLY) triggers robust neutrophil (PMN) infiltration that promotes bacterial transepithelial migration in vitro and disseminated disease in mice. Apical infection of polarized respiratory epithelial monolayers by S. pneumoniae at a multiplicity of infection (MOI) of 20 resulted in recruitment of PMNs, loss of 50% of the monolayer, and PMN-dependent bacterial translocation. Reducing the MOI to 2 decreased PMN recruitment two-fold and preserved the monolayer, but apical-to-basolateral translocation of S. pneumoniae remained relatively efficient. At both MOI of 2 and 20, PLY was required for maximal PMN recruitment and bacterial translocation. Co-infection by wild type S. pneumoniae restored translocation by a PLY-deficient mutant, indicating that PLY can act in trans. Investigating the contribution of S. pneumoniae infection on apical junction complexes in the absence of PMN transmigration, we found that S. pneumoniae infection triggered the cleavage and mislocalization of the adherens junction (AJ) protein E-cadherin. This disruption was PLY-dependent at MOI of 2 and was recapitulated by purified PLY, requiring its pore-forming activity. In contrast, at MOI of 20, E-cadherin disruption was independent of PLY, indicating that S. pneumoniae encodes multiple means to disrupt epithelial integrity. This disruption was insufficient to promote bacterial translocation in the absence of PMNs. Thus, S. pneumoniae triggers cleavage and mislocalization of E-cadherin through PLY-dependent and PLY-independent mechanisms, but maximal bacterial translocation across epithelial monolayers requires PLY-dependent neutrophil transmigration.
Large-scale column-free purification of bovine F-ATP synthase
Authors: Chimari Jiko , Morimoto Yukio , Tsukihara Tomitake , Gerle Christoph
Published: June 2023

Mammalian F-ATP synthase is central to mitochondrial bioenergetics and is present in the inner mitochondrial membrane in a dynamic oligomeric state of higher oligomers, tetramers, dimers and monomers. In vitro investigations of mammalian F-ATP synthase are often limited by the ability to purify the oligomeric forms present in vivo at sufficient quantity, stability and purity. We developed a purification approach for the isolation of bovine F-ATP synthase from heart muscle mitochondria that uses a combination of buffer conditions favouring IF1 binding and sucrose density gradient ultracentrifugation to yield stable complexes at high purity in the milligram range. By tuning the GDN to LMNG ratio in a final gradient, fractions that are either enriched in tetrameric or monomeric F-ATP synthase can be obtained. It is expected that this large-scale column-free purification strategy broadens the spectrum of in vitro investigation on mammalian F-ATP synthase.
Using the metaverse in training: lessons from real cases
Authors: Hajjami Omaima , Park Sunyoung
Published: June 2023

Purpose

The purpose of this study is to explore the potential contribution of the metaverse to improve training and development as a function of human resource development (HRD) perspective. The authors explore the benefits and challenges of the metaverse and introduce cases of companies using the metaverse in training.

Design/methodology/approach

A narrative literature review was conducted to collect information on the metaverse in training. The authors reviewed peer- and non-peer-reviewed articles, book chapters, white papers, corporate websites and blogs and business magazines.

Findings

A total of 75 articles were reviewed, including 14 cases, which were summarized to demonstrate how companies are applying metaverse technology in training contexts. For a more in-depth review, three cases were selected and summarized in terms of context, process and outcomes.

Originality/value

The metaverse is an emergent topic in HRD. It has the potential to revolutionize the functions of training and development through the combination of advanced technologies, including virtual reality, augmented reality and mixed reality. This article is the foundational attempt to provide a comprehensive summary of existing literature and case studies that highlight the potential of the metaverse in training within the context of HRD.
Key influencing factors for the success of external innovation strategies in the biotechnology industry
Authors: Lin Meichun , Lekhawipat Watcharee
Published: June 2023

Purpose

Numerous biotechnology and pharmaceutical firms have undergone considerable changes and adapted to the challenge of developing sustainable products and services. However, few studies have explored the factors that contribute to the success of external innovation and value co-creation strategies adopted by biotechnology and pharmaceutical firms. The purpose of this study is to examine how biotechnology and pharmaceutical industries use value co-creation strategies to obtain external resources.

Design/methodology/approach

This study developed a conceptual framework based on the relevant literature. The study applied a resource-based approach, dynamic capability theory and a qualitative multiple-case study design to investigate several research questions; semi-structured interviews were conducted with representatives from 11 biotechnology/pharmaceutical firms in Taiwan, and the data extracted from the interview content were axially coded.

Findings

This study revealed that factors such as dynamic marketing capabilities and process optimization contributed to the success of the aforementioned strategies; several propositions were also developed on the basis of the literature review and coded data, thereby providing insights regarding the relative efficacy and propriety of various external innovation and value co-creation strategies and models in various situations and contexts. Firms and technology providers might enter a technology licensing agreement, establish a joint venture company; participate in a merger/acquisition depending on their size, research and development capabilities; or goals and time- and cost-related factors.

Originality/value

The main original contributions of this study are the proposed conceptual framework and the insights provided regarding the relative efficacy and propriety of different external innovation and value co-creation strategies and models in different situations and contexts.
Analysing and predicting a country’s entrepreneurial activity using insights from entrepreneurs’ digital footprint
Authors: Tekic Zeljko , Parfenov Andrei , Malyy Maksim
Published: June 2023

Purpose

Starting from intention–behaviour models and building upon the growing evidence that aggregated internet search query data represent a good proxy of human interests and intentions. The purpose of this study is to demonstrate that the internet search traffic information related to the selected key terms associated with establishing new businesses, reflects well the dynamics of entrepreneurial activity in a country and can be used for predicting entrepreneurial activity at the national level.

Design/methodology/approach

Theoretical framework is based on intention–behaviour models and supported by the knowledge spillover theory of entrepreneurship. Monthly data on new business registration from 2018 to 2021 is derived from the open database of the Russian Federal Tax Service. Terms of internet search interest are identified through interviews with the recent founders of new businesses, whereas the internet search query statistics on the identified terms are obtained from Google Trends and Yandex Wordstat.

Findings

The results suggest that aggregated data about web searches related to opening a new business in a country is positively correlated with the dynamics of entrepreneurial activity in the country and, as such, may be useful for predicting the level of that activity.

Practical implications

The results may serve as a starting point for a new approach to measure, monitor and predict entrepreneurial activities in a country and can help in better addressing policymaking issues related to entrepreneurship.

Originality/value

To the best of the authors’ knowledge, this study is original in its approach and results. Building on intention–behaviour models, this study outlines, to the best of the authors’ knowledge, the first usage of big data for analysing the intention–behaviour relationship in entrepreneurship. This study also contributes to the ongoing debate about the value of big data for entrepreneurship research by proposing and demonstrating the credibility of internet search query data as a novel source of quality data in analysing and predicting a country’s entrepreneurial activity.
Evaluation of the drivers to the implementation of blockchain technology in the construction supply chain management in Nigeria
Authors: Okanlawon Taofeek Tunde , Oyewobi Luqman Oyekunle , Jimoh Richard Ajayi
Published: June 2023

Purpose

Blockchain technology (BT) is a relatively new technological innovation in all industries, including the construction industry, that is used to improve supply chain management. Therefore, this study assesses the drivers for the implementation of BT in the construction supply chain management in Nigeria.

Design/methodology/approach

This study used a quantitative research approach, with a questionnaire survey administered to professionals in the Nigerian construction industry using the snowball sampling method, yielding 155 respondents. The collected data were analysed using descriptive and exploratory factor analysis (EFA) while Cronbach’s alpha was used to evaluate the reliability.

Findings

The analysis revealed that all the identified drivers ranked higher than the average mean item score, with level of awareness of the new technology and data management ranking topmost. The identified drivers were clustered into five categories using EFA: technological driver, social-economic driver, management driver, transparency and security driver and information driver.

Research limitations/implications

This research was carried out in the Southwestern region which is one of the six geo-political zones in Nigeria using a cross-sectional survey method.

Practical implications

The findings will be extremely useful to both professionals and practitioners in the Nigerian construction industry in gaining knowledge about the potential drivers to the implementation of BT in construction supply chain management.

Originality/value

The research categorized the drivers into technological, social-economic, management, transparency and security and information driver. It also identified that level of awareness of BT as the major driver in the implementation of BT in construction supply chain management.
Is training a green innovation driver? The mediating role of knowledge acquisition
Authors: Barba-Aragón María Isabel , Jiménez-Jiménez Daniel
Published: June 2023

Purpose

The purpose of this study is to contribute to empirical research on green innovation drivers. This paper analyzes the relationships between training, knowledge acquisition, green innovation and firm performance.

Design/methodology/approach

The analysis is carried out on a sample of 373 Spanish companies from a wide variety of sectors. This research has used the partial least squares (PLS) model to test the hypotheses.

Findings

It is found that green innovation and knowledge acquisition improve firm performance, and that knowledge acquisition has a mediating effect between training and green innovation.

Practical implications

The findings of this article indicate that green innovation allows the company to obtain benefits while reducing the negative environmental impact, then managers should bet on ecological innovation. This study also shows that there is an indirect effect of training on green innovation and, therefore, managers must invest in training as a mechanism to increase knowledge acquisition and, thus, green innovation.

Originality/value

This paper analyzes two research areas that have received little attention: the role of human resource management in green innovation and the relationship between a given driver and green innovation. In the first, it analyzes whether training increases green innovation, and in the second, it considers the effect of training on knowledge acquisition and on green innovation, specifically, it studies whether knowledge acquisition mediates the relationship between training and green innovation.
Crypto-asset market development: the role of country’s institutional quality
Authors: Škrabić Perić Blanka , Rimac Smiljanić Ana , Jerković Ivana
Published: June 2023

Purpose

Crypto-asset can be traded on many different exchanges worldwide with servers located in countries with different financial characteristics and institutional surroundings. Trading volume on these servers varies considerably regarding the server’s location, even though the prices do not differ greatly. Crypto-asset markets are poorly regulated and, as such, may leave a place for potential fraudulent activities and be linked to corruption. This paper aims to examine the role of country’s institutions in attracting Bitcoin traders.

Design/methodology/approach

Assuming heterogeneity between countries where crypto-asset exchange servers are located, the Pool Mean Group Estimator is used.

Findings

Results indicate that, from institutional variables, corruption in the country attracts while internal and external conflicts repel investors. Additionally, the growth of global uncertainty and the decline in the local stock markets motivate investors to trade Bitcoin.

Originality/value

Previous research has empirically proved the importance of institutions’ quality for financial market development. This paper goes one step further and tries to empirically confirm the theoretical assumptions and investigate in detail the role of institutions in choosing servers in a particular country for Bitcoin trading.
Wetting kinetics, spreading phenomena and interfacial reaction of Sn-15Bi-xZn solders on Cu substrate at different temperatures
Authors: Lin Wei , Li Xuewen , Tu Bing , Zhang Chaohua , Li Yulong
Published: June 2023

Purpose

This study aims to analyze the wettability of the self-developed Sn–Bi–Zn solder and to conduct a series of analysis on the wetting kinetics, diffusion phenomenon and interfacial reaction of Sn–Bi–Zn solder on Cu substrate.

Design/methodology/approach

The wetting kinetics, diffusion phenomenon and interfacial reaction of Sn–Bi–Zn solder on Cu substrate were analyzed by experiments. The interface was observed by scanning electron microscope to study the effect of Zn content on its interface.

Findings

With the increase in brazing temperature, the final spreading equivalent radius of the solder increases significantly, and the final contact angle of the solder decreases significantly. In addition, when the Zn content is 1%, the spreading effect of solder is the best, the equivalent radius is the largest and the contact angle is the smallest. According to the microstructural analysis, the thick intermetallic compounds layer of the Sn–15Bi–xZn solders on the Cu substrate can be effectively decreased by adding appropriate Zn content.

Originality/value

The wetting kinetics, diffusion phenomenon and interfacial reaction of Sn–15Bi–xZn solder on Cu substrate at different temperatures have not been studied yet.
Scavenger and herbivore functional role impairment modulates changes in plant communities following mass mortality events
Authors: Baruzzi C. , Barton B. T. , Cove M. V. , Strickland B. K. , Lashley M. A.
Published: June 2023

Mass mortality events (MMEs) of wildlife are increasingly frequent and may destabilize communities. MMEs provide a unique ecological context because they simultaneously produce a resource pulse that is sometimes coupled with the loss or severe impairment of functional roles such as predation or herbivory. Moreover, these effects are complicated by global declines in obligate vertebrate scavengers.

We designed an experiment to measure the relative importance of bottom‐up (nutrient addition) and top‐down (impairment of obligate scavenger and herbivore functional roles) forces experienced during MMEs on the local plant community.

Increasing carrion biomass shifted local plant assemblages from the original state promoting plants more resistant to soil disturbance (i.e. annual plants), but this effect was unique to carrion as the same amount of macronutrients entering the system did not affect the plant community. This may indicate that the effects of carrion are primarily driven by interactions with consumers rather than bottom‐up processes. Additionally, restricting obligate vertebrate scavenger access to increasing amounts of carrion biomass shifted the net effects of the carrion on the plant community by limiting perennial vines. Impairment of the herbivore functional role released plants from top‐down control, increasing plant growth and survival.

Our experiment indicates that top‐down forces may have strong effects on plant communities following MMEs. As such, the global increase in wildlife MMEs may have broad consequences on ecological communities, not only on the species affected.

Read the free Plain Language Summary for this article on the Journal blog.
Examining rural income and employment in Bangladesh: A case of structural changes in the rural nonfarm sector in a developing country
Authors: Iqbal Kazi , Pabon Md Nahid Ferdous , Ibon Md Wahid Ferdous
Published: June 2023

This study uncovers some important stylised facts about the structural changes in the rural nonfarm (RNF) economy in Bangladesh for the period 2000–2016 and identifies some broad determinants. Our work uses household‐level, secondary sources such as Household Income and Expenditure Survey, Labour Force Survey and Bangladesh Integrated Household Survey. We find that the positive relationship between landownership and rural income has become weaker in recent years, indicating the increasing role of nonland inputs in generating rural income. The share of RNF income in total rural income has increased substantially over the years. The increase in nonfarm income is largely driven by the nonfarm wage income of the richer households, indicating adverse distributional consequences. There are also indications for specialisation in nonfarm activities—the share of income from the ‘mixed’ sources of farm and nonfarm has decreased, and the ‘only nonfarm’ source has increased. Households tend to move away from agriculture and specialise in RNF occupations as the education level increases. Our results offer important insights into rural development strategies and contribute to the broader questions of the development discourse on the structural changes in developing countries.
Characterisation and identification of key cardboard‐like off‐odour compounds and possible origins in yoghurt using HS‐SPME‐GC–MS
Authors: Ye Zhi‐Kang , Lin Qin‐Bao , Zeng Ying , Liu Ai‐Jie , Li Dan , Zhong Huai‐Ning , Zhang Yi‐Cai , Xu Xiaowen
Published: June 2023

Cardboard‐like off‐odour in yoghurt can negatively impact consumer acceptability. Herein, a method has been developed to analyse off‐odorants in yoghurt using headspace solid‐phase microextraction coupled with gas chromatography–mass spectrometry. Of 56 volatile organic compounds identified, 8 were active compounds responsible for cardboard‐like off‐odour, including 2, 2‐dimethyl‐propanoic acid and 3‐methyl‐2‐pentanone, which were newly identified in yoghurt. Hexanol and hexanal were found to be indicators of quality deterioration. The off‐odour may be caused by packaging materials and temperature changes during logistic activities. Overall, identifying off‐odorants can help producers to determine which part of the yoghurt‐producing process can be changed to avoid contamination.
Financial constraints and political catering disclosures of non‐state‐owned firms: Evidence from textual analysis
Authors: Kong Dongmin , Shi Lu
Published: June 2023

Using textual analysis techniques, we construct a novel measure to quantify the level of political information in forward‐looking disclosures of privately controlled firms. Our results show that private firms with serious financial constraints are more likely to reveal more political information in forward‐looking disclosures. Plausible mechanisms driving our findings are firms' high growth, under‐investment, and weaker political connections, suggesting that firms cater to governments in the expectation of more financing resources. Finally, we show the economic consequences of political catering strategy on corporate performance.
Life‐history traits govern the habitat use of diverse amphibian assemblages in an agroforest landscape matrix
Authors: Sankararaman V. , Miller D. A. W.
Published: June 2023

Agroforests are increasingly seen as ancillary conservation landscapes that effectively integrate production needs while sustaining biodiversity goals. The conservation potential of these land uses can be significantly improved by using evidence‐based management practices. In this study, we examine the community assembly of anuran amphibians and identify vulnerable species based on their life‐history traits across tea and coffee agroforests and non‐agricultural forest fragments in the Anamalai Hills of India. We conducted visual and auditory encounter surveys for amphibians along streams and terrestrial habitats. A modified joint species distribution model was used to examine the drivers of species richness, community composition and species co‐occurrence patterns. At the community level, mean species richness was greatest in forest fragments followed by coffee and least in tea agroforests. Community composition was associated with both land use (tea/coffee/forest) and habitat (stream/terrestrial), with the greatest composition difference between coffee and forest. Life‐history traits were significant drivers of species occupancies, particularly in forests. Fast‐flowing water breeding amphibians and smaller body sizes were positively associated with forest streams over coffee and tea streams. Elevation was a strong predictor of amphibian occupancy with nine species showing negative association and 14 species showing positive association. Twelve species also showed a significant positive association with the wetter year, seven of which belonged to direct‐developing frogs. This suggests that even single‐year declines in rainfall could have detrimental effects on populations and make these species vulnerable to climate change. The results of the study have important conservation consequences for agroforests in the Western Ghats. Stream restoration efforts across elevation gradients could significantly improve habitats for different amphibian assemblages in agroforests.
Secondary alopecia induced by aesthetic procedures: An unrecognized potential complication
Authors: Barrera‐Ochoa Carlos A. , Alonso‐León María Teresa , Arenas Roberto , Vega‐Memjie Maria Elisa , Asz‐Sigall Daniel
Published: June 2023

Surgical facelifts and noninvasive techniques such as mesotherapy, hyaluronic fillers and botulinum toxin, among other procedures are widely used nowadays to reverse skin ageing and achieve rejuvenation effects. Secondary alopecia due to cosmetic procedures is a rare side effect and is poorly described in the literature. The mechanisms in which hair loss develops after an aesthetical procedure or surgical technique are not well known. The development of secondary scarring alopecia or non‐scarring alopecia depends upon the interaction between different external factors, the individual host response and the extent of damage to the hair follicle anatomy. Current knowledge hints at the type of substance used, pressure to hair structures and vasculature due to the materials used, previously unknown or unaware hair disorder, and poor surgical techniques to be the main factors contributing to the development of secondary alopecia. Physicians and patients must be aware of all the substances used for the procedures and be attentive to any change in hair density or hair loss. Clinicians must have a low threshold to take biopsies if the risk of scarring alopecia may occur. Herein, we review the clinical, trichoscopic, histopathological findings and potential pathophysiological mechanisms of hair loss due to different aesthetic procedures.
Multifactorial causes of chronic itch in diabetes: More than just neuropathy
Authors: Pérez Buenfil Luis Angel , Fortier Julia , Almeda‐Valdes Paloma , Güereca Olguín Diana Cecilia , Mena‐Hernández Lourdes , Corona‐Hernández María de los Ángeles , Lima‐Galindo Anabell Andrea , Barbosa Bibiana , Sánchez‐Gomez Josué Ernesto , Hernández Amparo , Domínguez‐Cherit Judith , Valdés‐Rodríguez Rodrigo
Published: June 2023

Background

Chronic pruritus is common in patients with diabetes though its pathophysiology is unknown and difficult to pinpoint given the multi‐system manifestations of diabetes. Herein, we aim to evaluate the severity of chronic itch in patients with diabetes and its association with glycaemic control, microvascular complications and quality of life.

Methods

We conducted a retrospective study of 105 adults with diabetes evaluated by a dermatologist at a tertiary care centre in Mexico City. Degree of chronic pruritus and its impact on quality of life as well as laboratory, clinical and demographic data were collected. Patients without chronic pruritus (n = 62) were compared to those with chronic pruritus (n = 43). The latter cohort was further stratified by itch severity, and characteristics of their itch were quantified.

Results

Neuropathy and loss of protective sensation were more common in patients with chronic pruritus, compared to those without chronic pruritus (p = 0.007 and p = 0.001, respectively). Anxiety and depression were more common in individuals with chronic pruritus (p = 0.009), and these group reported higher effect of pruritus on their quality of life (p < 0.0001). The most common sites of itch were the head, back and arms. Among patients with chronic itch, increasing itch severity was associated with decreasing eGFR (p = 0.080).

Conclusions

The underlying cause of chronic itch in patients with diabetes is likely multifactorial and owing to microvascular complications such as neuropathy and nephropathy. Better understanding of the causes of itch in these patients can allow for more targeted treatment, leading to improved quality of life.
Day surgery for endometriosis in Canada: A retrospective cohort of trend and regional variation in types of surgeries and their complications
Authors: Bahrami Foruzan , Maheux‐Lacroix Sarah , Bougie Olga , Boutin Amélie
Published: June 2023

Background

A significant proportion of patients with endometriosis require surgery for management of the disease.

Aims

We aimed to assess the trend and regional variation in day surgeries for endometriosis across Canada and to identify perioperative complications associated with types of surgeries and their temporal trend and regional variation.

Materials and Methods

We conducted a retrospective cohort study of women undergoing day surgeries for endometriosis between 2015 and 2019 using Canadian administrative data from the National Ambulatory Care Reporting System, which includes data from four provinces (Ontario (ON), Alberta (AB), Nova Scotia (NS) and Prince Edward Island (PEI)). Multivariate logistic regression models were used to compare perioperative complication rates, while adjusting for site(s) of endometriosis lesion, age, type of surgical intervention, and comorbidities.

Results

During the study period, the rate of day surgeries for endometriosis remained nearly constant at 80–90 cases per 100 000 women of reproductive age (P = 0.12). The rate of day surgeries was significantly different between provinces (AB = 94, NS = 93 vs ON = 85 per 100 000 women of reproductive age: P < 0.02).

The odds of complications decreased with time (2019 vs 2015; adjusted odds ratio (aOR): 0.84; 95% CI: 0.73–0.98). There was a significant regional variation in the frequency of perioperative complications (PEI vs ON aOR: 4.13, 95% CI: 2.58–6.62; and NS vs ON aOR: 1.47, 95% CI: 1.11–1.95).

Conclusion

The rates of day surgery for endometriosis remained stable and the risks of perioperative complications decreased during the five‐year study period. However, there were significant regional variations in the risk of perioperative complications.
Right posterior bile duct stricture after laparoscopic anterior sectionectomy with long right bile duct: A case report
Authors: Hori Yuya , Ueno Masaki , Miyamoto Atsushi , Hayami Shinya , Okada Ken‐ichi , Kitahata Yuji , Kawai Manabu
Published: June 2023

Right anterior liver sectionectomy (RAS) is a complicated procedure with high incidences of postoperative complications. We report a case of right posterior bile duct (RPBD) stricture after laparoscopic RAS with discussion of the anatomical aspects. A 69‐year‐old Japanese man had solitary colorectal liver metastasis. A tumor was located near the root of the right anterior Glissonean pedicle. On postoperative day 6, he had cholangitis and imaging studies showed RPBD stricture. Symptoms disappeared following a course of antibiotics and the patient was discharged on postoperative day 21. The RBPD anatomy type of this patient was a supra‐portal pattern with a long (18 mm) right biliary duct, which would be close to the right anterior Glissonean bifurcation. A stapling device might have caused its deformation and resulted in its stricture. As the RPBD has variant anatomy, we had to notice that there may be hazardous types for postoperative RPBD stricture.
Structural and taxonomic diversity predict above‐ground biomass better than functional measures of maximum height in mixed‐species forests
Authors: Mensah Sylvanus , Noulèkoun Florent , Salako Valère K. , Lokossou Christa S. M. J. , Akouété Pathmos , Seifert Thomas , Glèlè Kakaï Romain
Published: June 2023

Aims:Mixed‐species forests are known to be highly productive systems because of their high species diversity, including taxonomic diversity (species richness) and structural diversity. Recent empirical evidence also points to plant maximum height, as a functional trait that potentially drives forest above‐ground biomass (AGB). However, the interrelations between these biotic variables are complex, and it is not always predictable if structural diversity attributes or functional metrics of plant maximum height would act as the most important determinant of stand biomass. Here we evaluated the relative importance of structural diversity attributes and functional metrics of plant maximum height (Hmax) in predicting and mediating AGB response to variation in species richness in mixed‐species forests, while also accounting for fine‐scale environmental variation.

Location:Northern Benin.

Methods:We used forest inventory data from mixed‐species stands of native and exotic species. We quantified structural diversity as coefficient of variation of tree diameter at breast height (CVdbh) and of height (CVHt). For plant Hmax, we computed three metrics: functional range (FRHmax), functional divergence (FDHmax) and community‐weighted mean (CWMHmax). We used topographical variables such as elevation and slope to account for possible environmental effects. Simple and multiple mixed‐effects models, and structural equation models were performed to assess the direct and indirect links of AGB with species richness through structural diversity attributes and functional metrics of plant Hmax.

Results:Species richness and CVdbh were positively related to AGB, while functional metrics of plant Hmax were not. Structural equation models revealed that species richness influenced AGB indirectly via CVdbh, which alone strongly promoted AGB. Elevation only had a positive direct effect on AGB. While increasing species richness enhanced CVdbh and functional measures of plant Hmax, there was no support for the latter mediating the effects of species richness on AGB.

Conclusion:Structural diversity has a significant advantage in predicting and mediating the positive effect of species richness on AGB more so than functional measures of plant Hmax. We argue that structural diversity acts as a mechanism for the species richness–AGB relationship, and that maintaining high structural diversity would enhance biomass in mixed‐species forests.