bluuebunny/crossref_metadata_2025 huggingface dataset:
p53-mediated neurodegeneration in the absence of the nuclear protein Akirin2
Authors: Peek Stacey L. , Bosch Peter J. , Bahl Ethan , Iverson Brianna J. , Parida Mrutyunjaya , Bais Preeti , Manak J. Robert , Michaelson Jacob J. , Burgess Robert W. , Weiner Joshua A.
Published: July 2021

Proper gene regulation is critical for both neuronal development and maintenance as the brain matures. We previously demonstrated that Akirin2, an essential nuclear protein that interacts with transcription factors and chromatin remodeling complexes, is required for the embryonic formation of the cerebral cortex. Here we show that Akirin2 plays a mechanistically distinct role in maintaining healthy neurons during cortical maturation. Restricting Akirin2 loss to excitatory cortical neurons resulted in progressive neurodegeneration via necroptosis and severe cortical atrophy with age. Comparing transcriptomes from Akirin2-null postnatal neurons and cortical progenitors revealed that targets of the tumor suppressor p53, a regulator of both proliferation and cell death encoded by Trp53, were consistently upregulated. Heterozygous deletion of Trp53 rescued neurodegeneration in Akirin2-null neurons. These data: 1) implicate Akirin2 as a critical neuronal maintenance protein; 2) identify p53 pathways as mediators of Akirin2 functions; and 3) suggest Akirin2 dysfunction may be relevant to neurodegenerative diseases.
Tracing the evolution of human gene regulation and its association with shifts in environment
Authors: Colbran Laura L. , Johnson Maya R. , Mathieson Iain , Capra John A.
Published: July 2021

As humans spread throughout the world, they adapted to variation in many environmental factors, including climate, diet, and pathogens. Because many of these adaptations were likely mediated by multiple non-coding variants with small effects on gene regulation, it has been difficult to link genomic signals of selection to specific genes, and to describe the regulatory response to selection. To overcome this challenge, we adapted PrediXcan, a machine learning method for imputing gene regulation from genotype data, to analyze low-coverage ancient human DNA (aDNA). First, we used simulated genomes to benchmark strategies for adapting gene regulatory prediction to increase robustness to incomplete aDNA data. Applying the resulting models to 490 ancient Eurasians, we found that genes with the strongest divergent regulation among ancient populations with hunter-gatherer, pastoralist, and agricultural lifestyles are enriched for metabolic and immune functions. Next, we explored the contribution of divergent gene regulation to two traits with strong evidence of recent adaptation: dietary metabolism and skin pigmentation. We found enrichment for divergent regulation among genes previously proposed to be involved in diet-related local adaptation, and in many cases, the predicted effects on regulation provide explanations for previously observed signals of selection, e.g., atFADS1,GPX1, andLEPR. For skin pigmentation, we applied new models trained in melanocytes to a time series of 2999 ancient Europeans spanning ~38,000 years BP. In contrast to diet, skin pigmentation genes show little regulatory change over time, suggesting that adaptation mainly involved large-effect coding variants. This work demonstrates how aDNA can be combined with present-day genomes to shed light on the biological differences among ancient populations, the role of gene regulation in adaptation, and the relationship between ancient genetic diversity and the present-day distribution of complex traits.
Message in a Bottle – Metabarcoding Enables Biodiversity Comparisons Across Ecoregions
Authors: Steinke D , deWaard SL , Sones JE , Ivanova NV , Prosser SWJ , Perez K , Braukmann TWA , Milton M , Zakharov EV , deWaard JR , Ratnasingham S , Hebert PDN
Published: July 2021

Background

Traditional biomonitoring approaches have delivered a basic understanding of biodiversity, but they cannot support the large-scale assessments required to manage and protect entire ecosystems. This study employed DNA metabarcoding to assess spatial and temporal variation in species richness and diversity in arthropod communities from 52 protected areas spanning three Canadian ecoregions.

Results

This study revealed the presence of 26,263 arthropod species in the three ecoregions and indicated that at least another 3,000–5,000 await detection. Results further demonstrate that communities are more similar within than between ecoregions, even after controlling for geographical distance. Overall α-diversity declined from east to west, reflecting a gradient in habitat disturbance. Shifts in species composition were high at every site with turnover greater than nestedness, suggesting the presence of many transient species.

Conclusions

Differences in species composition among their arthropod communities confirm that ecoregions are a useful synoptic for biogeographic patterns and for structuring conservation efforts. The present results also demonstrate that metabarcoding enables large-scale monitoring of shifts in species composition, making it possible to move beyond the biomass measurements that have been the key metric employed in prior efforts to track change in arthropod communities.
Members of the CUGBP Elav-Like Family of RNA-Binding Proteins are Expressed in Distinct Populations of Primary Sensory Neurons
Authors: Grlickova-Duzevik Eliza , Reimonn Thomas M , Michael Merilla , Tian Tina , Owyoung Jordan , McGrath-Conwell Aidan , Neufeld Peter , Mueth Madison , Molliver Derek C , Ward Patricia Jillian , Harrison Benjamin J
Published: July 2021

Primary sensory Dorsal Root Ganglia (DRG) neurons are diverse, with distinct populations that respond to specific stimuli. Previously, we observed that functionally distinct populations of DRG neurons express mRNA transcript variants with different 3’ untranslated regions (3’UTR’s). 3’UTRs harbor binding sites for interaction with RNA-binding proteins (RBPs) for transporting mRNAs to subcellular domains, modulating transcript stability and regulating the rate of translation. In the current study, analysis of publicly available single-cell RNA-Sequencing (scRNA-Seq) data generated from adult mice revealed that 17 3’UTR-binding RBPs were enriched in specific populations of DRG neurons. This included 4 members of the CUGBP Elav-Like Family (CELF): CELF2 and CELF4 were enriched in peptidergic, CELF6 in both peptidergic and nonpeptidergic and CELF3 in tyrosine hydroxylase-expressing neurons.

Immunofluorescence studies confirmed that 60% of CELF4+ neurons are small diameter C fibers and 33% medium diameter myelinated (likely Aδ) fibers and showed that CELF4 is distributed to peripheral termini. Co-expression analyses using transcriptomic data and immunofluorescence revealed that CELF4 is enriched in nociceptive neurons that express GFRA3, CGRP and the capsaicin receptor TRPV1. Re-analysis of published transcriptomic data from macaque DRG revealed a highly similar distribution of CELF members, and re-analysis of single-nucleus RNA sequencing data derived mouse and rat DRG after sciatic injury revealed differential expression of CELFs in specific populations of sensory neurons. We propose that CELF RNA-binding proteins may regulate the fate of mRNAs in populations of nociceptors, and may play a role in pain and/or neuronal regeneration following nerve injury.
Find me if you can: Pre- and Post-hurricane Densities of the Red-bellied Racer (Alsophis rufiventris) on St. Eustatius, and a review of the genus in the Caribbean
Authors: Madden Hannah , Fernández Denny S. , Tremblay Raymond L. , Verdel Kevin , Kaboord Brent
Published: July 2021

We estimated population densities of the red-bellied racer (Alsophis rufiventris) on the Caribbean island of St. Eustatius in 2011, 2018 and 2019 to determine the likely influence of hurricanes Irma and Maria (September 2017), in addition to evaluating abiotic parameters which may be correlated with its presence. Surveys were conducted at seven sites in 2011 prior to the hurricanes, and at 81 and 108 sites in 2018 and 2019 respectively posterior to the hurricanes. A total of 8.2 ha was surveyed in 2011, and 11.42 ha in 2018/2019. The pre-hurricane (2011) racer density estimate was 9.2/ha (min 7.3 - max 11.6); post-hurricane estimates were 4.6/ha (min 3.4 - max 6.0) in 2018 and 5.0/ha (min 3.8 - max 6.5) in 2019. The pre-hurricane encounter rate of individual racers was 16.0 snakes/hour compared to 0.34 snakes/hour in 2018 and 0.41 snakes/hour in 2019 (post-hurricane). The decrease in encounter rates between 2011 and 2019 implies a negative impact of the hurricanes on racer abundance. Based on calculations of detection probability (0.02 in 2018 and 0.03 in 2019), post-hurricane lambda estimates were 1.82 (95% CI 0.66 - 5.01) in 2018 and 1.60 (95% CI 0.39 - 6.65) snakes/ha in 2019. Given the current small size of the remaining population and the presence of invasive species across the snake’s range, this species could be at risk of local extirpation. We suggest conservation actions such as invasive species management and habitat restoration to enable further recovery.
All-trans retinoic acid induces synaptopodin-dependent metaplasticity in mouse dentate granule cells
Authors: Lenz Maximilian , Eichler Amelie , Kruse Pia , Muellerleile Julia , Deller Thomas , Jedlicka Peter , Vlachos Andreas
Published: July 2021

The vitamin A derivative all-trans retinoic acid (atRA) is a key mediator of synaptic plasticity. Depending on the brain region studied, distinct effects of atRA on excitatory and inhibitory neurotransmission have been reported. However, it remains unclear how atRA mediates brain region-specific effects on synaptic transmission and plasticity. Here, we used intraperitoneal injections of atRA (10 mg/kg) in adult male C57BL/6J mice to study the effects of atRA on excitatory and inhibitory neurotransmission in the mouse fascia dentata. In contrast to what has been reported in other brain regions, no major changes in synaptic transmission were observed in the ventral and dorsal hippocampus 6 hours after atRA administration. Likewise, no evidence for changes in the intrinsic properties of hippocampal dentate granule cells was obtained in the atRA-treated group. Moreover, hippocampal transcriptome analysis revealed no essential changes upon atRA treatment. In light of these findings, we tested for the metaplastic effects of atRA, i.e., for its ability to modulate synaptic plasticity expression in the absence of major changes in baseline synaptic transmission. Indeed, in vivo long-term potentiation (LTP) experiments demonstrated that systemic atRA treatment improves the ability of dentate granule cells to express LTP. The plasticity-promoting effects of atRA were not observed in synaptopodin-deficient mice, thus extending our previous results on the relevance of synaptopodin in atRA-mediated synaptic strengthening in the mouse prefrontal cortex. Taken together, our data show that atRA mediates synaptopodin-dependent metaplasticity in mouse dentate granule cells.
Linguistic modulation of the neural encoding of phonemes
Authors: Kim Seung-Goo , De Martino Federico , Overath Tobias
Published: July 2021

Speech comprehension entails the neural mapping of the acoustic speech signal onto learned linguistic units. This acousto-linguistic transformation is bi-directional, whereby higher-level linguistic processes (e.g., semantics) modulate the acoustic analysis of individual linguistic units. Here, we investigated the cortical topography and linguistic modulation of the most fundamental linguistic unit, the phoneme. We presented natural speech and ‘phoneme quilts’ (pseudo-randomly shuffled phonemes) in either a familiar (English) or unfamiliar (Korean) language to native English speakers while recording fMRI. This allowed us to dissociate the contribution of acoustic vs. linguistic processes towards phoneme analysis. We show that (1) the acoustic analysis of phonemes is modulated by linguistic analysis and (2) that for this modulation both of acoustic and phonetic information need to be incorporated. These results suggest that the linguistic modulation of cortical sensitivity to phoneme classes minimizes prediction error during natural speech perception, thereby aiding speech comprehension in challenging listening situations.
Compound-specific, concentration-independent biophysical properties of sodium channel inhibitor mechanism of action
Authors: Pesti Krisztina , Földi Mátyás C. , Zboray Katalin , Toth Adam V. , Lukacs Peter , Mike Arpad
Published: July 2021

We have developed an automated patch-clamp protocol that allows high information content screening of sodium channel inhibitor compounds. We have observed that individual compounds had their specific signature patterns of inhibition, which were manifested irrespective of the concentration. Our aim in this study was to quantify these properties. Primary biophysical data, such as onset rate, the shift of the half inactivation voltage, or the delay of recovery from inactivation, are concentration-dependent. We wanted to derive compound-specific properties, therefore, we had to neutralize the effect of concentration. This study describes how this is done, and shows how compound-specific properties reflect the mechanism of action, including binding dynamics, cooperativity, and interaction with the membrane phase. We illustrate the method using four well-known sodium channel inhibitor compounds, riluzole, lidocaine, benzocaine, and bupivacaine. Compound-specific biophysical properties may also serve as a basis for deriving parameters for kinetic modeling of drug action. We discuss how knowledge about the mechanism of action may help to predict the frequency-dependence of individual compounds, as well as their potential persistent current component selectivity. The analysis method described in this study, together with the experimental protocol described in the accompanying paper, allows screening for inhibitor compounds with specific kinetic properties, or with specific mechanisms of inhibition.
Adolescent dopamine neurons represent reward differently during action and state guided learning
Authors: McCane Aqilah M. , Wegener Meredyth A. , Faraji Mojdeh , Garcia Maria T. Rivera , Wallin-Miller Kathryn , Costa Vincent D. , Moghaddam Bita
Published: July 2021

The neuronal underpinning of learning cause-and-effect associations in the adolescent brain remains poorly understood. Two fundamental forms of associative learning are Pavlovian (classical) conditioning, where a stimulus is followed by an outcome, and operant (instrumental) conditioning, where outcome is contingent on action execution. Both forms of learning, when associated with a rewarding outcome, rely on midbrain dopamine neurons in the ventral tegmental area (VTA) and substantia nigra (SN). We find that in adolescent male rats, reward-guided associative learning is encoded differently by midbrain dopamine neurons in each conditioning paradigm. Whereas simultaneously recorded VTA and SN adult neurons have a similar phasic response to reward delivery during both forms of conditioning, adolescent neurons display a muted reward response during operant but a profoundly larger reward response during Pavlovian conditioning suggesting that adolescent neurons assign a different value to reward when it is not gated by action. The learning rate of adolescents and adults during both forms of conditioning was similar further supporting the notion that differences in reward response in each paradigm are due to differences in motivation and independent of state versus action value learning. Static characteristics of dopamine neurons such as dopamine cell number and size were similar in the VTA and SN but there were age differences in baseline firing rate, stimulated release and correlated spike activity suggesting that differences in reward responsiveness by adolescent dopamine neurons are not due to differences in intrinsic properties of these neurons but engagement of different networks.
Network-level containment of single-species bioengineering
Authors: Maull Victor , Solé Ricard
Published: July 2021

Ecological systems are facing major diversity losses in this century due to Anthropogenic effects. Habitat loss, overexploitation of resources, invasion and pollution are rapidly jeopardising the survival of whole communities, as revealed by pronounced population losses. Moreover, the potential of future tipping points further complicate their survival and change our perspective of risk. It has been recently suggested that a potential approach to flatten the curve of species extinction and prevent catastrophic shifts would involve the engineering of one selected species within one of these communities, aiming at helping the maintenance of key conditions compatible with high diversity. Such possibility has started to become part of potential intervention scenarios to preserve coral reefs, kelp forests or soil microbiomes in drylands. Despite its potential, very little is known about the actual dynamic responses of complex ecological networks to the introduction of a synthetic strains derived from a resident species. In this paper we address this problem by modelling the response of a competitive community to the addition of a synthetic strain derived from a member of a stable ecosystem. We show that the community interaction matrix largely limits the spread of the engineered strain, thus suggesting that species diversity acts as an ecological firewall. Implications for future restoration and terraformation strategies are discussed.
Microglia and border-associated mouse macrophages maintain their embryonic origin during Alzheimer’s disease
Authors: Wu Xiaoting , Saito Takashi , Saido Takaomi C. , Barron Anna M. , Ruedl Christiane
Published: July 2021

Brain microglia and border-associated macrophages (BAMs) display distinct spatial, developmental, and phenotypic features. Although at steady-state, the origins of distinct brain macrophages are well-documented, the dynamics of their replenishment in neurodegenerative disorders remain elusive, particularly for disease-associated microglia (DAMs) and BAMs. In this study, we conducted a comprehensive fate-mapping analysis of murine microglia and BAMs and their turnover kinetics during Alzheimer’s disease (AD) progression. We used a novel inducible AD mouse model to investigate the contribution of bone marrow cells to the pool of foetal-derived brain macrophages during the development of AD. We demonstrated that microglia and DAMs remain a remarkably stable embryonic-derived population even during the progression of AD pathology, indicating that neither parenchymal macrophage subpopulation originates from, nor are replenished by, monocytes. At the border-associated brain regions, bona fide CD206+ BAMs are minimally replaced by monocytes, and their turnover rates are not accelerated by AD. In contrast, all other myeloid cells are swiftly replenished by bone marrow progenitors. This information further elucidates the turnover kinetics of these cells not only at steady-state, but also in neurodegenerative diseases, which is crucial for identifying potential novel therapeutic targets.

Impact statement

Inducible fate-mapping analysis demonstrates that neither microglia, disease-associated microglia nor border-associated macrophages are replenished by bone marrow-derived cells in Alzheimer’s disease.
Sexually distinct song cultures in a songbird metapopulation
Authors: Webb Wesley H. , Roper Michelle M. , Pawley Matthew D. , Fukuzawa Yukio , Harmer Aaron M. , Brunton Dianne H.
Published: July 2021

Songbirds learn their songs culturally, through imitating tutors. The vocal culture of a songbird population changes as new song units (syllables) are introduced through immigration, copying errors, and innovation, while other syllables fall out of use. This leads to a diversification of the syllable pool across the species, much like the diversification and spatial patterns of human language. Vocal cultures have been well studied in male songbirds but have been largely overlooked in females. In particular, few studies compare spatial variation of male and female song cultures. Here we undertake one of the first comparisons of male and female song culture in birds, analysing song data from a metapopulation of New Zealand bellbirds Anthornis melanura, spanning an archipelago of six islands. Having classified 20,700 syllables, we compare population syllable repertoire sizes and overlap between sites and sexes. We show that males and females—both with complex songs—have distinct song cultures, sharing only 6–26% of syllable types within each site. Furthermore, male and female syllable types can be statistically discriminated based on acoustic properties. Despite diverse syllable repertoires within sites, few syllable types were shared between sites (both sexes had highly distinct site-specific dialects). For the few types shared between sites, sharing decreased with distance only for males. Overall, there was no significant difference between sexes in degree of site–site repertoire overlap. These results suggest different cultural processes at play for the two sexes, underlining the inadequacy of male-centric song research and calling for comparisons of male and female song cultures in many more species.
Algorithms for the discovery of cis-eQTL signals in woody species: the vine (Vitis viniferaL.) as a study model
Authors: Martínez-García Pedro José , Mas-Gómez J , Wegrzyn Jill , Botía Juan A.
Published: July 2021

Expression quantitative trait loci (eQTLs), are associations between genetic variants, such as Single Nucleotide Polymorphisms (SNPs), and gene expression. eQTLs are an important tool to understand the genetics of gene expression of complex phenotypes. eQTLs analysis are common in human studies and in model species such as mice, rats and yeast but are very scarce in wood crop species such as fruit trees or grapevines. In this study a comprehensive bioinformatic pipeline has been carried out using genomics and expression data from 10 genotypes of grape, which has been used as model species. As a result of this study a total of 10,618 genetic variants that regulate gene expression levels of 525 genes were detected. A 78% of them, 411, received a functional annotation from UniProtKB or DAVID, between the annotated protein-coding genes are Germin-like proteins (GLPs), auxin-regulatory factors, GRFS, ANK_REP_REGION domain-containing protein, Kinesin motor domain-containing protein or RPP13like protein 2(LOC100852873). This new inventory of cis eQTLs influencing gene expression during the ripening of fruits ofVitis viniferaL. will be an important resource for future research to understand the mechanistic basis for variation in gene regulation in this species. In the future, this methodology may be applied to other woody species, once the necessary databases are generated.
Irisin stimulates the release of CXCL1 from differentiating human subcutaneous and deep-neck derived adipocytes via upregulation of NFκB pathway
Authors: Shaw Abhirup , Tóth Beáta B , Király Róbert , Arianti Rini , Csomós István , Póliska Szilárd , Vámos Attila , Korponay-Szabó Ilma R , Bacso Zsolt , Győry Ferenc , Fésüs László , Kristóf Endre
Published: July 2021

Thermogenic brown and beige adipocytes play an important role in combating obesity. Recent studies in rodents and humans have indicated that these adipocytes release cytokines, termed “batokines”. Irisin was discovered as a polypeptide regulator of beige adipocytes released by myocytes, primarily during exercise. We performed global RNA sequencing on adipocytes derived from human subcutaneous and deep-neck precursors, which were differentiated in the presence or absence of irisin. Irisin did not exert an effect on the expression of characteristic thermogenic genes, while upregulated genes belonging to various cytokine signaling pathways. Out of the several upregulated cytokines,CXCL1, the highest upregulated, was released throughout the entire differentiation period, and predominantly by differentiated adipocytes. Deep-neck area tissue biopsies also showed a significant release of CXCL1 during 24 hours irisin treatment. Gene expression data indicated upregulation of the NFкB pathway upon irisin treatment, which was validated by an increase of p50 and decrease of IкBα protein level, respectively. Continuous blocking of the NFκB pathway, using a cell permeable inhibitor of NFκB nuclear translocation, significantly reduced CXCL1 release. The released CXCL1 exerted a positive effect on the adhesion of endothelial cells. Together, our findings demonstrate that irisin stimulates the release of a novel “batokine”, CXCL1, via upregulation of NFκB pathway in neck area derived adipocytes, which might play an important role in improving tissue vascularization.
Identification of the cell-type-specific ER membrane protein Tanmp expressed in hypothalamic tanycytes and subsets of neurons
Authors: Takahashi Osamu , Tanahashi Mayuko , Yokoi Saori , Kaneko Mari , Tokuhara Tomoko , Yanaka Kaori , Nakagawa Shinichi , Maita Hiroshi
Published: July 2021

Genomes of higher eukaryotes encode many uncharacterized proteins, and the functions of these proteins cannot be predicted from the primary sequences due to a lack of conserved functional domains. During a screening of novel noncoding RNAs abundantly expressed in mouse brains, we incidentally identified a gene termed Tanmp, which encoded an endoplasmic reticulum (ER) protein without known functional domains. Tanmp is specifically expressed in the nervous system, and the highest expression was observed in a specialized cell type called tanycyte that aligns the ventral wall of the third ventricle in the hypothalamus. Immunostaining of Tanmp revealed the fine morphology of tanycytes with highly branched apical ER membranes. Immunoprecipitation revealed that Tanmp associates with mitochondrial ATPase at least in vitro, and ER and mitochondrial signals occasionally overlapped in tanycytes. Mutant mice lacking Tanmp did not exhibit overt phenotypes, suggesting that Tanmp is not essential in mice reared under normal laboratory conditions. We also found that RNA probes that are predicted to uniquely detect Tanmp mRNA cross-reacted with uncharacterized RNAs, highlighting the importance of experimental validation of the specificity of probes during the hybridization-based study of RNA localization.
Glial place cells: complementary encoding of spatial information in hippocampal astrocytes
Authors: Curreli Sebastiano , Bonato Jacopo , Romanzi Sara , Panzeri Stefano , Fellin Tommaso
Published: July 2021

Calcium dynamics into astrocytes influence the activity of nearby neuronal structures. However, because previous reports show that astrocytic calcium signals largely mirror neighboring neuronal activity, current information coding models neglect astrocytes. Using simultaneous two-photon calcium imaging of astrocytes and neurons in the hippocampus of mice navigating a virtual environment, we demonstrate that astrocytic calcium signals actively encode spatial information. Calcium events carrying spatial information occurred in topographically organized astrocytic subregions. Importantly, astrocytes encoded spatial information that was complementary and synergistic to that carried by neurons, improving spatial position decoding when astrocytic signals were considered alongside neuronal ones. These results suggest that the complementary place-dependence of localized astrocytic calcium signals regulates clusters of nearby synapses, enabling dynamic, context-dependent, variations in population coding within brain circuits.
Current-account breaks and stability spells in a global perspective
Authors: Camba-Crespo Alfonso , García-Solanes José , Torrejón-Flores Fernando
Published: July 2021

Purpose

This study aims to identify structural breaks in the current account and the periods between these breaks, which the authors name stability spells, and study their characteristics and determinants.

Design/methodology/approach

Using data from the IMF and the World Bank, this study applies the Lee and Strazicich test to endogenously identify breaks and the Heckman selection model to simultaneously study the determinants of structural breaks and current-account changes after breaks.

Findings

This study identifies 212 significant structural breaks and 341 stability spells. These spells become shorter and more volatile the further they are from equilibrium, and half of them last 10 years or less. The results show that economic growth and foreign-exchange piling are particularly useful to prevent breaks, while lower per capita income increases exposure to break risks.

Originality/value

This study introduces the concept of current-account stability spells to refer to the periods between structural breaks. These spells are then studied to determine their main characteristics. The authors also apply a global perspective in their analysis, using a wide sample of 181 economies between 1980 and 2018 and considering positive and negative breaks in both level and trend.
The impact of high-tech companies’ performance and growth on capital structure
Authors: Spitsin Vladislav , Vukovic Darko B. , Spitsina Lubov , Özer Mustafa
Published: July 2021

Purpose

The purpose of this paper is to investigate the joint influence of two factors (companies’ performance and growth) on the company’s capital structure and to determine the conditions for financially sustainable competitive strategies in the coordinates profitability and growth.

Design/methodology/approach

The study sample includes 1,996 companies from 6 high-tech industries in Russia (panel data: 7,984 observations). The authors use regression models with random effects and carry out a three-dimensional visualization of the resulting dependencies.

Findings

The study found that profitability improves the capital structure (reduces the share of borrowed capital) and, on the contrary, the growth of companies (assets growth or sales growth) increases the leverage ratio. In the case of assets growth, the combined influence of two factors reduces the negative effect of assets growth. The results have shown that the outstripping growth of most high-tech companies requires an increase in debt capital and deterioration in the capital structure and financial stability.

Practical implications

In general, based on the results of this study, the authors have identified groups of fast-growing companies that need financial support, and have defined the main areas of impact (reducing the loan burden and increasing profitability) that will allow these companies to maintain high growth rates and demonstrate advanced development.

Originality/value

The relationships (which the authors identified between the control variables, the studied variables and leverage) were obtained for the first time for a sample of companies in high-tech industries and services in bigger transition country (Russia).
Dynamic asymptotic model of rolling bearings with a pitting fault based on fractional damping
Authors: Li Yunlong , Li Zhinong , Wang Dong , Peng Zhike
Published: July 2021

Purpose

The purpose of this paper is to discuss the asymptotic models of different parts with a pitting fault in rolling bearings.

Design/methodology/approach

For rolling bearings with a pitting fault, the displacement deviation between raceways and rolling elements is usually considered to vary instantaneously. However, the deviation should change gradually. Based on this shortcoming, the variation rule and calculation method of the displacement deviation are explored. Asymptotic models of different parts with a pitting fault are discussed, respectively. Besides, rolling bearing systems have prominent fractional characteristics unconsidered in the traditional models. Therefore, fractional calculus is introduced into the modeling of rolling bearings. New dynamic asymptotic models of different parts with a pitting fault are proposed based on fractional damping. The numerical simulation is performed based on the proposed model, and the dynamic characteristics are analyzed through the bifurcation diagrams, trajectory diagrams and frequency spectrograms.

Findings

Compared with the model based on integral calculus, the proposed model can better reflect the periodic characteristics and fault characteristics of rolling bearings. Finally, the proposed model is verified by the experiment. The dynamic characteristics of rolling bearings at different rotating speeds are analyzed. The experimental results are consistent with the simulation results. Therefore, the proposed model is effective.

Originality/value

(1) The above models are idealized, i.e. the local pitting fault is treated as a rectangle. When a component comes into contact with the fault, the displacement deviation between the component and the fault component immediately releases if the component enters the fault area and restores if the component leaves. However, the displacement deviation should change gradually. Only when the component touches the fault bottom, the displacement deviation reaches the maximum. (2) Due to the material's memory and fluid viscoelasticity, rolling bearing systems exhibit significant fractional characteristics. However, the above models are all proposed based on integral calculus. Integral calculus has some local characteristics and is not suitable for describing historical dependent processes. Fractional calculus can better describe the essential characteristics of the system.
Seeing through their eyes: the diversity and inclusion lessons learned from rural university students
Authors: Browers Catherine S. , Ho Henry Wai Leong
Published: July 2021

Purpose

In recent years, diversity and inclusion in higher education has become a topic of increased interest both nationally and internationally. Given the importance of this topic in today's world, it is surprising that the research is limited, especially with university students in the rural areas. This study examines on-campus students' perceptions of university diversity initiatives, and their value to the university environment.

Design/methodology/approach

Focus-group interviews with both undergraduate and graduate students from a public university in rural Michigan, USA, were conducted. Focus groups were used in this study because they are a particularly good method for generating discussion and stimulating ideas.

Findings

Overall, the participants identified several positive attitudes toward diversity and inclusion that included being accepting and respectful. However, it is significant that some participants are limited in their perceptions of culturally diverse backgrounds, which has resulted in some anxiety.

Originality/value

This study not only provides guidance to current institution administrators to create effective inclusive environments in their university. It can also be treated as a model for other rural universities, as building a successful inclusive environment in the future.
Distribution planning problem of a supply chain of perishable products under disruptions and demand stochasticity
Authors: Suryawanshi Pravin , Dutta Pankaj
Published: July 2021

Purpose

The emergence of risk in today's business environment is affecting every managerial decision, majorly due to globalization, disruptions, poor infrastructure, forecasting errors and different uncertainties. The impact of such disruptive events is significantly high for perishable items due to their susceptibility toward economic loss. This paper aims to design and address an operational planning problem of a perishable food supply chain (SC).

Design/methodology/approach

The proposed model considers the simultaneous effect of disruption, random demand and deterioration of food items on business objectives under constrained conditions. The study describes this situation using a mixed-integer nonlinear program with a piecewise approximation algorithm. The proposed algorithm is easy to implement and competitive to handle stationary as well as nonstationary random variables in place of scenario techniques. The mathematical model includes a real-life case study from a kiwi fruit distribution industry.

Findings

The study quantifies the performance of SC in terms of SC cost and fill rate. Additionally, it investigates the effects of disruption due to suppliers, transport losses, product perishability and demand stochasticity. The model incorporates an incentive-based strategy to provide cost-cutting in the existing business plan considering the effect of deterioration. The study performs sensitivity analysis to show various “what-if” situations and derives implications for managerial insights.

Originality/value

The study contributes to the scant literature of quantitative modeling of food SC. The research work is original as it integrates a stochastic (uncertain) nature of SC simultaneously coupled with the effect of disruption, transport losses and product perishability. It incorporates proactive planning strategies to minimize the disruption impact and the concept of incremental quantity discounts on lot sizes at a destination node.
Patient hospital experience and satisfaction on social media
Authors: Chakraborty Subhajit , Church E. Mitchell
Published: July 2021

Purpose

The purpose of this paper is to show the value of open-ended narrative patient reviews on social media for elucidating aspects of hospital patient satisfaction.

Design/methodology/approach

Mixed methods analyses using qualitative (manual content analyses using grounded theory and algorithmic analyses using the Natural Language Toolkit) followed by quantitative analyses (negative binomial regression).

Findings

Health-care team communication, health-care team action orientation and patient hospital room environment are positively related to patient hospital satisfaction. Patients form their hospital satisfaction perceptions based on the three facets of their hospital stay experience.

Research limitations/implications

In the spirit of continuous quality improvement, periodically analyzing patient social media comments could help health-care teams understand the patient satisfaction inhibitors that they need to avoid to offer patient-centric care.

Practical implications

By periodically analyzing patient social media comments hospital leaders can quickly identify the gaps in their health service delivery and plug them, which could ultimately give the hospital a competitive advantage.

Originality/value

To the best of the authors’ knowledge, this is one of the first studies to apply mixed methods to patient hospital review comments given freely on social media to critically understand what drives patient hospital satisfaction ratings.
Impact of customers' interpersonal interactions in social commerce on customer relationship management performance
Authors: Hossain Md Shamim , Rahman Mst Farjana , Zhou Xiaoyan
Published: July 2021

Purpose

Social commerce is a subpart of electronic commerce (e-commerce), where social media is forced to support user contributions. The purpose of this study is to measure the impact of customers' interpersonal interactions in social commerce on customer relationship management (CRM) performance, based on the flow, commitment-trust and stimulus–organism–response (SOR) theories.

Design/methodology/approach

On the basis of the SOR framework, the authors developed a study model to determine the impact on CRM performance of customers' interpersonal interactions in social commerce. The primary data of the study were collected from 640 users of social commerce through a web questionnaire during the COVID-19 (coronavirus disease 2019) pandemic situation, and the authors tested the study model using the approach of covariance-based structural equation modeling (SEM).

Findings

Results of the current study reveal that customers' interpersonal interactions in social commerce optimistically influence their perceived flow. Moreover, perceived flow absolutely controls users' trust and CRM performance. In turn, collective users' trust positively influences users' commitment and CRM performance. Finally, collective users' commitment absolutely influences the performance of CRM.

Practical implications

The authors provide a valuable contribution to the theoretical field of online marketing and CRM. Besides, the findings of this study are relevant for marketers to know the issues for increasing customer trust, commitment and performance of CRM.

Originality/value

The current study develops a model based on the flow, commitment-trust and stimulus–organism–response (SOR) theories. The authors' research is the first to estimate the effect of customers' interpersonal interactions in social commerce on CRM performance.
Addressing cumulative harm: responding to chronic child maltreatment in the context of an intensive family support service
Authors: Collier Simone , Bryce India
Published: July 2021

Purpose

Adverse childhood experiences that are consistently experienced over a sustained period of time throughout childhood result in an accumulation of childhood adversity, which is often referred to in the literature as cumulative harm. This paper aims to closely examine statutory child protection practice, which favours an episodic and incident-focused approach to assessing risk and harm, failing to account for the evaluation of the accumulation of adversity and harm, commonly experienced by children exposed to maltreatment. The paper defines an existing gap in practice frameworks to adequately identify and respond to the accumulation of adversity.

Design/methodology/approach

Drawing on practice experiences in Queensland Australia, the paper examines service delivery responses to cumulative harm in the context of the Intensive Family Support model of service delivery.

Findings

Within current frameworks for child protection service delivery, there is no method of assessing the diverse and cumulative effects of ongoing chronic child maltreatment and adversity, despite research confirming that cumulative harm very often co-occurs with other child protection concerns. To effectively and collaboratively intervene in matters of chronic and cumulative abuse and neglect, practitioners and stakeholders must be guided by frameworks and assessments that accurately recognise and acknowledge the impact of ongoing exposure to adverse experiences and maltreatment.

Research limitations/implications

The need for a valid and reliable assessment method that draws together all elements contributing to the chronic maltreatment experience for a child and family: multiplicity, diversity and severity.

Social implications

Practice solutions tailored to each child’s specific cumulative experiences of adversity and maltreatment will promote better social, emotional and health outcomes across the lifespan.

Originality/value

This paper highlights a significant gap in assessment and practice frameworks and advances the impetus for cumulative harm to be proactively integrated into social care and service delivery.
Perceived threat and officer-involved shootings: characteristics leading to fatal vs non-fatal instances
Authors: Nazaretian Zavin , Heraux Cedrick , Merolla David
Published: July 2021

Purpose

The purpose of this research is to compare the fatality rate of Black and White subjects shot by police. This comparison is meant to explore whether officer-involved shootings (OIS) are impacted more by perceived threat or by demographic characteristics. Beyond race, contextual and officer-level variables are examined for their influence on lethal vs non-lethal police shootings.

Design/methodology/approach

The study utilizes data from the Tampa Bay Times database on police shootings in Florida from 2009 through 2014. Our analysis focuses on the substantive importance of this issue, using the population of OIS in one specific state over a specified time period. The authors also including multinomial logistic regression models analyzing the impact of race, contextual and officer-level variables on the lethal outcome of OIS is clear that the police are shooting at two very different populations.

Findings

Although Black subjects are disproportionately represented as the subjects of OIS, there was no significant difference in the lethality of such incidents based simply on race. However, when we compare Black subjects to White subjects, it is clear that the police are shooting at two very different populations. Black subjects were younger, less likely to be armed, less likely to be under the influence of drugs or alcohol, and less likely to have suspected or known mental health considerations than their White counterparts.

Research limitations/implications

Thus, it is possible that any racialized difference in the lethality of police shootings is being suppressed because we are comparing very different groups of subjects to one another.

Originality/value

This paper is the first to examine the racial threat that officers experience past the decision to engage in violence. The authors are looking at how they shoot at minorities vs the decision to shoot at minorities.
Analysing competing logics towards sustainable supplier management
Authors: León Bravo Verónica , Jaramillo Villacrés Mariuxy , Silva Minelle E.
Published: July 2021

Purpose

To understand the context surrounding the sustainable supplier management (SSM) process (i.e. selection, development and evaluation), this paper aims to explore institutional logics existing in the Ecuadorian cocoa supply chain (SC). By considering local characteristics and sustainability practices, this study illustrates how competing logic influences SSM.

Design/methodology/approach

This paper uses a multiple-case study method for which the authors interviewed different cocoa SC members in Ecuador and used a ground-up approach to analyse the data and reveal singularities influencing sustainability management.

Findings

The analysis uncovered two main logics operating within the Ecuadorian cocoa SC SSM process: a commercial logic (e.g. potential for market access, product traceability) and a sustainability logic (e.g. local development and traditions/cultural issues). These logics address market demand requirements; however, some local producers’ needs that impact SSM remains unexplored such as the existence of a regional ancestral culture that poses sustainability as a dominant logic with meaning beyond the triple bottom line. While the two logics have influenced supplier sustainability performance, this paper finds that, of the three SSM sub-processes (selection, development and evaluation), supplier development was the most relevant sub-process receiving attention from SC managers in the studied context.

Practical implications

By understanding the differences in logic and needs, SC managers can better develop strategies for SSM.

Originality/value

The study highlighted in this paper investigated the underexplored topic of the effects that competing logic may have on SSM. This paper focusses on the supplier’s point of view regarding sustainability requirements, addressing a consistent research gap in the literature.