bluuebunny/crossref_metadata_2025 huggingface dataset:
Short OGA is targeted to the mitochondria and regulates mitochondrial reactive oxygen species level
Authors: Pagesy Patrick , Bouaboud Abdelouhab , Feng Zhihao , Hulin Philippe , Issad Tarik
Published: December 2021

O-GlcNAcylation is a reversible post-translational modification involved the regulation of cytosolic, nuclear and mitochondrial proteins. Only two enzymes, OGT and OGA, control attachment and removal of O-GlcNAc on proteins, respectively. Whereas a variant OGT (mOGT) has been proposed as the main isoform that O-GlcNAcylates proteins in mitochondria, identification of a mitochondrial OGA has not been performed yet. Two splice variants of OGA (short and long isoforms) have been described previously. In this work, using cell fractionation experiments, we show that short-OGA is preferentially recovered in mitochondria-enriched fractions from HEK-293T cells as well as mouse embryonic fibroblasts. Moreover, fluorescent microscopy imaging confirmed that GFP-tagged short-OGA is addressed to mitochondria. In addition, using a BRET-based mitochondrial O-GlcNAcylation biosensor, we show that co-transfection of short-OGA markedly reduced O-GlcNAcylation of the biosensor, whereas long-OGA had no significant effect. Finally, using genetically encoded or chemical fluorescent mitochondrial probes, we showed that short-OGA overexpression increases mitochondrial ROS levels, whereas long-OGA had no significant effect. Together, our work reveals that the short-OGA isoform is targeted to the mitochondria where it regulates ROS homoeostasis.
Rapid and sensitive single cell RNA sequencing with SHERRY2
Authors: Di Lin , Liu Bo , Lyu Yuzhu , Zhao Shihui , Pang Yuhong , Zhang Chen , Wang Jianbin , Qi Hai , Shen Jie , Huang Yanyi
Published: December 2021

Prevalent single cell transcriptomic profiling (scRNA-seq) mechods are mainly based on synthesis and enrichment of full-length double-stranded complementary DNA. These approaches are challenging to generate accurate quantification of transcripts when their abundance is low or their full-length amplifications are difficult. Based on our previous finding that Tn5 transposase can directly cut-and-tag DNA/RNA hetero-duplexes, we present SHERRY2, a specifically optimized protocol for scRNA-seq without second strand cDNA synthesis. SHERRY2 is free of pre-amplification and eliminates the sequence-dependent bias. In comparison with other widely-used scRNA-seq methods, SHERRY2 exhibits significantly higher sensitivity and accuracy even for single nuclei. Besides, SHERRY2 is simple and robust, and can be easily scaled up to high-throughput experiments. When testing single lymphocytes and neuron nuclei, SHERRY2 not only obtained accurate countings of transcription factors and long non-coding RNAs, but also provided bias-free results that enriched genes in specific cellular components or functions, which outperformed other protocols. With a few thousand cells sequenced by SHERRY2, we confirmed expression and dynamics of Myc in different cell types of germinal centers, which were previously only revealed by gene-specific amplification methods. SHERRY2 is able to provide high sensitivity, high accuracy, and high throughput for those applications that require high number of genes identified in each cell. It can reveal the subtle transcriptomic difference between cells and facilitate important biological discoveries.
Gdnf, a germ cell-derived factor, regulates zebrafish germ cell stemness through the creation of new spermatogonial niches (germ and Sertoli cells) and inhibition of spermatogonial differentiation in an autocrine and paracrine manners
Authors: Doretto Lucas B. , Butzge Arno J. , Nakajima Rafael T. , Martinez Emanuel R. M. , Marques Beatriz , da Silva Rodrigues Maira , Rosa Ivana F. , Ricci Juliana M. B. , Tovo-Neto Aldo , Costa Daniel F. , Malafaia Guilherme , Shao Changwei , Nóbrega Rafael H.
Published: December 2021

Glial cell line-derived neurotrophic factor (GDNF) and its receptor (GDNF Family Receptor α1 - GFRα1) are well known to mediate spermatogonial stem cell (SSC) proliferation and survival in the mammalian testes. In nonmammalian species, Gdnf and Gfrα1 orthologs have been found but their functions remain poorly investigated in the testis. Considering this background, this study aimed to understand the roles of Gdnf-Gfrα1 signaling pathway in the zebrafish testis by combining in vivo, in silico and ex vivo approaches. Our analysis showed that zebrafish exhibited two paralogs of Gndf (gdnfa and gdnfb) and its receptor, Gfrα1 (gfrα1a and gfrα1b), in agreement with the teleost-specific third round (3R) of whole genome duplication. Expression analysis further revealed that gdnfa and gfrα1a were the most expressed copies in the zebrafish adult testes. Subsequently, we demonstrated that gdnfa is expressed in the germ cells, while Gfrα1a was detected in early spermatogonia (mainly in types Aund and Adiff) and Sertoli cells. Functional ex vivo analysis showed that Gdnf promoted the creation of new available niches by stimulating proliferation of both type Aund spermatogonia and their surrounding Sertoli cells, but without changing pou5f3 mRNA levels. Strikingly, Gdnf also inhibited late spermatogonial differentiation as shown by the decrease of type B spermatogonia and down-regulation of dazl in the co-treatment with Fsh. Altogether, our data revealed for the first time that a germ cell-derived factor is associated with maintaining germ cell stemness through the creation of new available niches, supporting development of differentiating spermatogonial cysts and inhibiting late spermatogonial differentiation in autocrine and paracrine manners.
Integrated cytometry with machine learning applied to high-content imaging of human kidney tissue for in-situ cell classification and neighborhood analysis
Authors: Winfree Seth , McNutt Andrew T. , Khochare Suraj , Borgard Tyler J. , Barwinska Daria , Sabo Angela R. , Ferkowicz Michael J. , Williams James C. , Lingeman James E. , Gulbronson Connor J , Kelly Katherine J. , Sutton Timothy A. , Dagher Pierre C. , Eadon Michael T. , Dunn Kenneth W. , El-Achkar Tarek M.
Published: December 2021

The human kidney is a complex organ with various cell types that are intricately organized to perform key physiological functions and maintain homeostasis. New imaging modalities such as mesoscale and highly multiplexed fluorescence microscopy are increasingly applied to human kidney tissue to create single cell resolution datasets that are both spatially large and multi-dimensional. These single cell resolution high-content imaging datasets have a great potential to uncover the complex spatial organization and cellular make-up of the human kidney. Tissue cytometry is a novel approach used for quantitative analysis of imaging data, but the scale and complexity of such datasets pose unique challenges for processing and analysis. We have developed the Volumetric Tissue Exploration and Analysis (VTEA) software, a unique tool that integrates image processing, segmentation and interactive cytometry analysis into a single framework on desktop computers. Supported by an extensible and open-source framework, VTEA’s integrated pipeline now includes enhanced analytical tools, such as machine learning, data visualization, and neighborhood analyses for hyperdimensional large-scale imaging datasets. These novel capabilities enable the analysis of mesoscale two and three-dimensional multiplexed human kidney imaging datasets (such as CODEX and 3D confocal multiplexed fluorescence imaging). We demonstrate the utility of this approach in identifying cell subtypes in the kidney based on labels, spatial association and their microenvironment or neighborhood membership. VTEA provides integrated and intuitive approach to decipher the cellular and spatial complexity of the human kidney and complement other transcriptomics and epigenetic efforts to define the landscape of kidney cell types.
Single-cell analysis of microglial transcriptomic diversity in subarachnoid hemorrhage
Authors: Chen Junfan , Sun Lei , Lyu Hao , Zheng Zhiyuan , Lai Huasheng , Wang Yang , Luo Yujie , Lu Gang , Chan Wai Yee , Zhang Yisen , Chen Xinyi , Li Zhongqi , Ko Ho , Wong Kwok Chu George
Published: December 2021

Background

Subarachnoid hemorrhage (SAH) is a severe stroke and the advanced treatment for SAH is still limited. Recent studies have shown that microglia-mediated neuroinflammation plays a critical role in the pathogenesis of SAH. Microglia can transform their states in response to central nervous system injury. However, the transcriptomic features of microglia remained unknown in SAH. Recent developed single-cell RNA sequencing (scRNA-seq) provides a possible way to solve this problem.

Methods

Endovascular perforation (EVP) murine SAH model was established to reproduce experimental SAH. Microglia states are examined with immune staining and quantitate analysis. Post-SAH microglial single-cell suspension were harvest and sequenced using 10X scRNA-seq platform. Then, the detailed single-cell transcriptomic characterization of post-SAH microglia were analyzed with bioinformatics.

Results

Transcriptional analysis revealed at least ten diverse microglial subgroups, including SAH-associated microglia (SAM), inflammatory-associated microglia (IAM) and proliferation-associated microglia (PAM), which all exhibit distinct marker gene expression patterns. Microglia subsets interaction reveals the functional relationship between elevated signaling pathways and microglial sub-populations in SAH. Receptor-ligand pair analysis revealed that complex inter-cellular interactions exist between the microglia subsets and other cell types, and indicated that microglia are important mediators of neuroinflammation after SAH. Integrated analysis with normal microglia further proved the existence of these microglia subpopulations and different gene markers associated with SAH were clarified.

Conclusions

Collectively, we first report the single-cell transcriptome of post-SAH microglia and found specific biomarkers related to the neuroinflammation in SAH. These results enhanced our understanding of the pathological mechanisms of microglial response to SAH, and may guide future development of SAH monitoring methods and therapeutics.
Species-specific mitochondria dynamics and metabolism regulate the timing of neuronal development
Authors: Iwata Ryohei , Casimir Pierre , Erkol Emir , Boubakar Leïla , Planque Mélanie , Ditkowska Martyna , Vints Katlijn , Poovathingal Suresh , Gaspariunaite Vaiva , Bird Matthew , Corthout Nikky , Vermeersch Pieter , Davie Kristofer , Gounko Natalia V. , Aerts Stein , Ghesquière Bart , Fendt Sarah-Maria , Vanderhaeghen Pierre
Published: December 2021

The evolution of species involves changes in the timeline of key developmental programs. Among these, neuronal development is considerably prolonged in the human cerebral cortex compared with other mammals, leading to brain neoteny. Here we explore whether mitochondria influence the species-specific properties of cortical neuron maturation. By comparing human and mouse cortical neuronal maturation at high temporal and cell resolution, we found a slower pattern of mitochondria development in human cortical neurons compared with the mouse, together with lower mitochondria metabolic activity, particularly oxidative phosphorylation. Stimulation of mitochondria metabolism in human neurons resulted in accelerated maturation, leading to excitable and complex cells weeks ahead of time. Our data identify mitochondria as important regulators of the pace of neuronal development underlying human-specific features of brain evolution.
Multivalent Interactions between Molecular Components Involved in Fast Endophilin Mediated Endocytosis Drive Protein Phase Separation
Authors: Mondal Samsuzzoha , Narayan Karthik , Botterbusch Samuel , Powers Imania , Zheng Jason , James Honey Priya , Jin Rui , Baumgart Tobias
Published: December 2021

A specific group of transmembrane receptors, including the β1-adrenergic receptor (β1-AR), is internalized through a non-clathrin pathway known as Fast Endophilin Mediated Endocytosis (FEME). A key question is: how does the endocytic machinery assemble and how is it modulated by activated receptors during FEME. Here we show that endophilin, a major regulator of FEME, undergoes a phase transition into liquid-like condensates, which facilitates the formation of multi-protein assemblies by enabling the phase partitioning of endophilin binding proteins. The phase transition can be triggered by specific multivalent binding partners of endophilin in the FEME pathway such as the third intracellular loop (TIL) of the β1-AR, and the C-terminal domain of lamellipodin (LPD). Other endocytic accessory proteins can either partition into, or target interfacial regions of, these condensate droplets. On the membrane, TIL promotes protein clustering in the presence of endophilin and LPD C-terminal domain. Our results demonstrate how the multivalent interactions between endophilin, LPD, and TIL regulate protein assembly formation on the membrane, providing mechanistic insights into the priming and initiation steps of FEME.
Vendor-neutral sequences and fully transparent workflows improve inter-vendor reproducibility of quantitative MRI
Authors: Karakuzu Agah , Biswas Labonny , Cohen-Adad Julien , Stikov Nikola
Published: December 2021

Purpose

We developed an end-to-end workflow that starts with a vendor-neutral acquisition and tested the hypothesis that vendor-neutral sequences decrease inter-vendor variability of T1, MTR and MTsat measurements.

Methods

We developed and deployed a vendor-neutral 3D spoiled gradient-echo (SPGR) sequence on three clinical scanners by two MRI vendors. We then acquired T1 maps on the ISMRM-NIST system phantom, as well as T1, MTR and MTsat maps in three healthy participants. We performed hierarchical shift function analysis in vivo to characterize the differences between scanners when the vendor-neutral sequence is used instead of commercial vendor implementations. Inter-vendor deviations were compared for statistical significance to test the hypothesis.

Results

In the phantom, the vendor-neutral sequence reduced inter-vendor differences from 8 - 19.4% to 0.2 - 5% with an overall accuracy improvement, reducing ground truth T1 deviations from 7 - 11% to 0.2 - 4%. In vivo we found that the variability between vendors is significantly reduced (p = 0.015) for all maps (T1, MTR and MTsat) using the vendor-neutral sequence.

Conclusion

We conclude that vendor-neutral workflows are feasible and compatible with clinical MRI scanners. The significant reduction of inter-vendor variability using vendor-neutral sequences has important implications for qMRI research and for the reliability of multicenter clinical trials.
Mistimed feeding disrupts circadian rhythms of male mating behavior and female preovulatory LH surges in mice
Authors: Kukino Ayaka , Walbeek Thijs J. , Sun Lori J. , Watt Alexander T. , Park Jin Ho , Kauffman Alexander S. , Butler Matthew P.
Published: December 2021

In rodents, eating at atypical circadian times, such as during the biological rest phase when feeding is normally minimal, reduces fertility. Prior findings suggest this fertility impairment is due, at least in part, to reduced mating success. However, the physiological and behavioral mechanisms underlying this reproductive suppression are not known. In the present study, we tested the hypothesis that mistimed feeding-induced infertility is due to a disruption in the normal circadian timing of mating behavior and/or the generation of pre-ovulatory luteinizing hormone (LH) surges (estrogen positive feedback). In the first experiment, male+female mouse pairs, acclimated to be food restricted to either the light (mistimed feeding) or dark (control feeding) phase, were scored for mounting frequency and ejaculations over 96 hours. Male mounting behavior and ejaculations were distributed much more widely across the day in light-fed mice than in dark-fed controls and fewer light-fed males ejaculated. In the second experiment, the timing of the LH surge, a well characterized circadian event driven by estradiol (E2) and the SCN, was analyzed from serial blood samples taken from ovariectomized and E2-primed female mice that were light-, dark-, or ad-lib-fed. LH concentrations peaked 2h after lights-off in both dark-fed and ad-lib control females, as expected, but not in light-fed females. Instead, the normally clustered LH surges were distributed widely with high inter-mouse variability in the light-fed group. These data indicate that mistimed feeding disrupts the temporal control of the neural processes underlying both ovulation and mating behavior, contributing to subfertility.
Identification of potential astrocytes in the teleost brain
Authors: Hui Tan Germaine Jia , Bei Cheow Kathleen Wen , Min Ho May Si , Jesuthasan Suresh
Published: December 2021

Astrocytes are abundant star-shaped glial cells in the mammalian brain, with essential roles in metabolism, development, homeostasis, response to injury, behavior, and learning. Surprisingly, most regions of the teleost brain are thought to lack astrocytes, based primarily on the use of GFAP (glial fibrillary acidic protein) as a marker1. Here, drawing on recent evidence that astrocytes are molecularly heterogeneous, we propose that astrocytes exist in the teleost brain, albeit of the olig2 subtype2. Highly branched cells are present throughout the zebrafish brain, as shown here in Tg(sox10:EGFP) fish and previously in Tg(olig2:GFP) fish. Transcriptome data indicates the presence of brain cells that are olig2 and sox10 positive, which also express the astrocyte markers sox9b, sparcl1 and slc1a2b but lack gfap and the oligodendrocyte marker mbp. In situ hybridization confirms that stellate sox10:EGFP cells express olig2 and sox9b, while immunofluorescence indicates that they lack HuC/D and GFAP. We suggest that these cells be classified as astrocytes as this may more accurately reflect their functions.
Perceptual uncertainty alternates top-down and bottom-up fronto-temporal network signaling during response inhibition
Authors: Tsumura Kaho , Shintaki Reiko , Takeda Masaki , Chikazoe Junichi , Nakahara Kiyoshi , Jimura Koji
Published: December 2021

Response inhibition is a primary executive control function that allows the withholding of inappropriate responses, and requires appropriate perception of the external environment to achieve a behavioral goal. It remains unclear, however, how response inhibition is achieved when goal-relevant information involves perceptual uncertainty. Twenty-six human participants of both sexes performed a go/no-go task where visually presented random-dot motion stimuli involved perceptual uncertainties. The right inferior frontal cortex (rIFC) was involved in response inhibition, and the middle temporal (MT) region showed greater activity when dot motions involved less uncertainty. A neocortical temporal region in the superior temporal sulcus (STS) specifically showed greater activity during response inhibition in more perceptually certain trials. In this STS region, activity was greater when response inhibition was successful than when it failed. Directional effective connectivity analysis revealed that in more coherent trials, the MT and STS regions showed enhanced connectivity to the rIFC, whereas in less coherent trials, the signal direction was reversed. These results suggest that a reversible fronto-temporal functional network guides response inhibition under perceptual uncertainty, and in this network, perceptual information in the MT is converted to control information in the rIFC via STS, enabling achievement of response inhibition.

Significance statement

Response inhibition refers to withholding inappropriate behavior and is an important for achieving goals. Often, however, decision must be made based on limited environmental evidence. We showed that successful response inhibition is guided by a neocortical temporal region that plays a hub role in converting perceived information coded in a posterior temporal region to control information coded in the prefrontal cortex. Interestingly, when a perceived stimulus becomes more uncertain, the prefrontal cortex supplements stimulus encoding in the temporal regions. Our results highlight fronto-temporal mechanisms of response inhibition in which conversion of stimulus-control information is regulated based on the uncertainty of environmental evidence.
A Musculoskeletal Model of the Hand and Wrist Capable of Simulating Functional Tasks
Authors: McFarland Daniel C. , Binder-Markey Benjamin I. , Nichols Jennifer A. , Wohlman Sarah J. , de Bruin Marije , Murray Wendy M.
Published: December 2021

Objective

The purpose of this work was to develop an open-source musculoskeletal model of the hand and wrist and to evaluate its performance during simulations of functional tasks.

Methods

The musculoskeletal model was developed by adapting and expanding upon existing musculoskeletal models. An optimal control theory framework that combines forward-dynamics simulations with a simulated-annealing optimization was used to simulate maximum grip and pinch force. Active and passive hand opening were simulated to evaluate coordinated kinematic hand movements.

Results

The model’s maximum grip force production matched experimental measures of grip force, force distribution amongst the digits, and displayed sensitivity to wrist flexion. Simulated lateral pinch strength fell within variability of in vivo palmar pinch strength data. Additionally, predicted activation for 7 of 8 muscles fell within variability of EMG data during palmar pinch. The active and passive hand opening simulations predicted reasonable activations and demonstrated passive motion mimicking tenodesis, respectively.

Conclusion

This work advances simulation capabilities of hand and wrist models and provides a foundation for future work to build upon.

Significance

This is the first open-source musculoskeletal model of the hand and wrist to be implemented during both functional kinetic and kinematic tasks. We provide a novel simulation framework to predict maximal grip and pinch force which can be used to evaluate how potential surgical and rehabilitation interventions influence these functional outcomes while requiring minimal experimental data.
Layer-specific mitochondrial diversity across hippocampal CA2 dendrites
Authors: Pannoni Katy , Gil Daniela , Cawley Mikel , Campbell Logan , Farris Shannon
Published: December 2021

CA2 is an understudied subregion of the hippocampus that is critical for social memory. Previous studies identified multiple components of the mitochondrial calcium uniporter (MCU) complex as selectively enriched in CA2, however the functional significance of this enrichment remains unclear. The MCU complex regulates calcium entry into mitochondria, which in turn regulates mitochondrial transport and localization to active synapses. We found that MCU is strikingly enriched in CA2 distal apical dendrites, precisely where CA2 neurons receive entorhinal cortical input carrying social information. Further, MCU-enriched mitochondria in CA2 distal dendrites are larger compared to mitochondria in CA2 proximal apical dendrites and neighboring CA1 apical dendrites, an effect also seen with genetically labeled mitochondria and electron microscopy. MCU overexpression in neighboring CA1 led to larger mitochondria preferentially in proximal dendrites compared to distal dendrites and controls, suggesting that MCU may act as a coincidence detector linking synaptic activity to mitochondrial morphology and function. Our findings demonstrate that mitochondria are molecularly and structurally diverse across hippocampal cell types and circuits, and implicate MCU expression in regulating mitochondrial mass and layer-specific dendritic localization. Functionally distinct mitochondria in CA2 distal dendrites may confer unique synaptic and circuit properties underlying CA2 function in social memory.
Exploring BIM-triggered organisational and professional culture change: a systematic literature review
Authors: Alankarage Sonali , Chileshe Nicholas , Rameezdeen Raufdeen , Edwards David J. , Samaraweera Aparna
Published: December 2021

Purpose

Building information modelling (BIM) has had a considerable impact on the socio-technical aspects of construction organisations. Culture has been considered an essential element in BIM practice. Hence, this paper aims to explore existing research relates to culture in the BIM context.

Design/methodology/approach

A systematic literature review (SLR) was conducted based on the PRISMA guidelines using 104 articles published between 2011 and 2020 and directed with a descriptive and content analysis.

Findings

The SLR results give evidence that culture in the BIM context is still an under-researched topic. Culture has been considered as both a dependent and independent factor in the BIM domain. Organisational BIM culture is a collection of fundamental beliefs established in a BIM using organisation and passed to new employees with the use of BIM. BIM using organisations are have either weak or strong BIM cultures. Proper analysis and understanding of the BIM culture of different organisations are necessary to realise the strategies of transformation from a weak BIM culture to a strong BIM culture.

Originality/value

To the best of the author's knowledge, this is the first SLR in BIM research that investigates the role of culture in the BIM setting. This study contributed to the existing body of knowledge by proposing a conceptual framework to understand and change a weak BIM culture of an organisation to a strong, matured BIM culture. This SLR serves as a future research basis in BIM-triggered culture.
The application of “deep learning” in construction site management: scientometric, thematic and critical analysis
Authors: Elghaish Faris , Matarneh Sandra T. , Alhusban Mohammad
Published: December 2021

Purpose

The digital construction transformation requires using emerging digital technology such as deep learning to automate implementing tasks. Therefore, this paper aims to evaluate the current state of using deep learning in the construction management tasks to enable researchers to determine the capabilities of current solutions, as well as finding research gaps to carry out more research to bridge revealed knowledge and practice gaps.

Design/methodology/approach

The scientometric analysis is conducted for 181 articles to assess the density of publications in different topics of deep learning-based construction management applications. After that, a thematic and gap analysis are conducted to analyze contributions and limitations of key published articles in each area of application.

Findings

The scientometric analysis indicates that there are four main applications of deep learning in construction management, namely, automating progress monitoring, automating safety warning for workers, managing construction equipment, integrating Internet of things with deep learning to automatically collect data from the site. The thematic and gap analysis refers to many successful cases of using deep learning in automating site management tasks; however, more validations are recommended to test developed solutions, as well as additional research is required to consider practitioners and workers perspectives to implement existing applications in their daily tasks.

Practical implications

This paper enables researchers to directly find the research gaps in the existing solutions and develop more workable applications to bridge revealed gaps. Accordingly, this will be reflected on speeding the digital construction transformation, which is a strategy over the world.

Originality/value

To the best of the authors’ knowledge, this paper is the first of its kind to adopt a structured technique to assess deep learning-based construction site management applications to enable researcher/practitioners to either adopting these applications in their projects or conducting further research to extend existing solutions and bridging revealed knowledge gaps.
Hypercompetition: a review and agenda for future research
Authors: Lindskov Annesofie
Published: December 2021

Purpose

The purpose of this study is to review and understand the dimensionality of hypercompetition, factors causing a hypercompetitive environment and the consequences of hypercompetition on markets. Thereby, the purpose of the study is to cover the main contributors in the research field of hypercompetition and explore their findings and different views on hypercompetition.

Design/methodology/approach

Systematically review 131 conceptual and empirical studies published or presented at a conference in the past 25 years, with the focus on the definitions, causes and consequences (or presumed effects) of hypercompetition. In the paper, I follow the well-known systematic literature review method by Tranfieldet al.(2003).

Findings

The contribution of the study is to advance the knowledge of researchers and managers, in such a way that it becomes easier for them to select relevant variables to measure hypercompetition and identify strategies for gaining temporary competitive advantages in hypercompetitive environments. The construct of hypercompetition required a consolidation of commonalities in the definitions and characteristics used by scholars, to ensure that proper assumptions and variables are being used to measure hypercompetition in future research. Several ways to measure the effects of hypercompetition on firms, industries and individuals have been proposed, but the field still lacks of a clear definition on how to directly measure the construct.

Practical implications

In this paper, I highlight three managerial implications of hypercompetition as follows: action-based strategy, the determinants of hypercompetition and the importance for managers of accurately establishing their firm’s competitive situation.

Originality/value

Previous reviews in the area have either focussed on specific components or effects of hypercompetition. The present study collectively takes into consideration the definitions, causes and consequences of hypercompetition on firms, industries and individuals. The contribution of the paper is to indicate future opportunities and challenges within research on hypercompetition.
Privacy concerns with using public data for suicide risk prediction algorithms: a public opinion survey of contextual appropriateness
Authors: Zimmer Michael , Logan Sarah
Published: December 2021

Purpose

Existing algorithms for predicting suicide risk rely solely on data from electronic health records, but such models could be improved through the incorporation of publicly available socioeconomic data – such as financial, legal, life event and sociodemographic data. The purpose of this study is to understand the complex ethical and privacy implications of incorporating sociodemographic data within the health context. This paper presents results from a survey exploring what the general public’s knowledge and concerns are about such publicly available data and the appropriateness of using it in suicide risk prediction algorithms.

Design/methodology/approach

A survey was developed to measure public opinion about privacy concerns with using socioeconomic data across different contexts. This paper presented respondents with multiple vignettes that described scenarios situated in medical, private business and social media contexts, and asked participants to rate their level of concern over the context and what factor contributed most to their level of concern. Specific to suicide prediction, this paper presented respondents with various data attributes that could potentially be used in the context of a suicide risk algorithm and asked participants to rate how concerned they would be if each attribute was used for this purpose.

Findings

The authors found considerable concern across the various contexts represented in their vignettes, with greatest concern in vignettes that focused on the use of personal information within the medical context. Specific to the question of incorporating socioeconomic data within suicide risk prediction models, the results of this study show a clear concern from all participants in data attributes related to income, crime and court records, and assets. Data about one’s household were also particularly concerns for the respondents, suggesting that even if one might be comfortable with their own being used for risk modeling, data about other household members is more problematic.

Originality/value

Previous studies on the privacy concerns that arise when integrating data pertaining to various contexts of people’s lives into algorithmic and related computational models have approached these questions from individual contexts. This study differs in that it captured the variation in privacy concerns across multiple contexts. Also, this study specifically assessed the ethical concerns related to a suicide prediction model and determining people’s awareness of the publicness of select data attributes, as well as which of these data attributes generated the most concern in such a context. To the best of the authors’ knowledge, this is the first study to pursue this question.
Stronger effect of litter quality than micro‐organisms on leaf and root litter C and N loss at different decomposition stages following a subtropical land use change
Authors: Liao Chang , Long Chunyan , Zhang Qian , Cheng Xiaoli
Published: December 2021

Litter decomposition contributes largely to global carbon (C) and nitrogen (N) cycling, and it is strongly determined by litter quality and microbial community composition in ways that are poorly understood.

Here, we conducted a 2‐year field litter decomposition experiment by collecting leaf and root litter of crops (from cropland), shrubs (from shrubland) and wood (from woodland) and placing samples for decomposition in woodland soil in central China to investigate the effects of litter quality and microbial community composition on C and N losses of leaf and root litter of three species under different decomposition stages.

Our results showed that the leaf litter C and N losses of shrubs were significantly higher than those of crops and wood, whereas the root litter C and N losses of crops were significantly higher than those of shrubs and wood. Generally, the leaf litter C and N losses of the three species were higher on average than those of fine root litter during the whole decomposition period. For the C loss of the three species, litter lignin and phosphorus as well as initial litter quality were predominant drivers of root litter decomposition, while litter lignin, cellulose and hemicellulose concentrations were dominant for leaf litter decomposition.

For N loss, litter stoichiometry and litter quality directly governed leaf and root litter N loss, and the initial litter quality largely regulated N loss at the late decomposition stage. Unexpectedly, the effect of microbial community composition on litter C and N losses was relatively weak and only exhibited an effect on litter C and N losses during the early stage of decomposition.

Thus, our results revealed the huge disparity in C and N loss of plant species and litter types at different decomposition stages, which should be considered jointly when evaluating their roles in plant–soil feedbacks under global land use change.

A free Plain Language Summary can be found within the Supporting Information of this article.
Climate change legacies contrastingly affect the resistance and resilience of soil microbial communities and multifunctionality to extreme drought
Authors: Dacal Marina , García‐Palacios Pablo , Asensio Sergio , Wang Juntao , Singh Brajesh K. , Maestre Fernando T.
Published: December 2021

Soil microbial communities largely determine the ability of soils to provide multiple functions simultaneously (i.e. soil multifunctionality; multifunctionality hereafter). However, a major research challenge is understanding how soil microbial communities and associated multifunctionality resist and recover from extreme climate events such as droughts, and how the legacy of past climatic conditions may constrain such responses.

Here, we used soils subjected to 7 years of reduced rainfall (~35% reduction), warming (3°C temperature increase) and their combination to assess climate change legacies on the resistance and resilience of both soil fungal and bacterial communities and multifunctionality to a subsequent extreme drought event (2 weeks at 3% water‐holding capacity). At the end of the extreme drought, and 1, 15 and 60 days after rewetting, we assessed bacterial and fungal community composition, richness and abundance, as well as a multifunctionality index based on eight functions related with soil carbon (C), nitrogen (N) and phosphorous (P) cycling.

Climate change legacies influenced the resistance and resilience of bacterial and fungal abundance to extreme drought, but not those of community composition, richness and multifunctionality. The resistance of bacterial and fungal abundance showed opposite responses to warming and reduced rainfall. Specifically, climate change legacies increased the resistance of fungal abundance, whereas they reduced that of bacterial abundance. The resistance and resilience of multifunctionality to extreme drought were not related to the resistance or resilience of bacterial and fungal communities. Yet, the resistance of multifunctionality was related to that ofChytridiomycota, whereas its resilience was related to that ofProteobacteria.

Overall, our results indicate that climate change legacies affected the resistance and resilience of soil bacterial and fungal abundance to a subsequent extreme drought event, but not those of their community composition, richness and multifunctionality. Our results provide new insights on how climate change legacies contrastingly influence the resistance and resilience of soil microbial communities and multifunctionality. Furthermore, our findings highlight the role that specific microbial taxa play in maintaining soil multifunctionality and recovering from extreme drought events predicted under anthropogenic climate change.

A freePlain Language Summarycan be found within the Supporting Information of this article.
Tropical forest dung beetle–mammal dung interaction networks remain similar across an environmental disturbance gradient
Authors: Chiew Li Yuen , Hackett Talya D. , Brodie Jedediah F. , Teoh Shu Woan , Burslem David F. R. P. , Reynolds Glen , Deere Nicolas J. , Vairappan Charles S. , Slade Eleanor M.
Published: December 2021

Conservation outcomes could be greatly enhanced if strategies addressing anthropogenic land‐use change considered the impacts of these changes on entire communities as well as on individual species. Examining how species interactions change across gradients of habitat disturbance allows us to predict the cascading consequences of species extinctions and the response of ecological networks to environmental change.

We conducted the first detailed study of changes in a commensalist network of mammals and dung beetles across an environmental disturbance gradient, from primary tropical forest to plantations, which varied in above‐ground carbon density (ACD) and mammal communities.

Mammal diversity changed only slightly across the gradient, remaining high even in oil palm plantations and fragmented forest. Dung beetle species richness, however, declined in response to lower ACD and was particularly low in plantations and the most disturbed forest sites. Three of the five network metrics (nestedness, network specialization and functionality) were significantly affected by changes in dung beetle species richness and ACD, but mammal diversity was not an important predictor of network structure. Overall, the interaction networks remained structurally and functionally similar across the gradient, only becoming simplified (i.e. with fewer dung beetle species and fewer interactions) in the most disturbed sites.

We suggest that the high diversity of mammals, even in disturbed forests, combined with the generalist feeding patterns of dung beetles, confer resilience to the commensalist dung beetle–mammal networks.

This study highlights the importance of protecting logged and fragmented forests to maintain interaction networks and potentially prevent extinction cascades in human‐modified systems.
The sources of sex differences in aging in annual fishes
Authors: Reichard Martin , Blažek Radim , Žák Jakub , Cellerino Alessandro , Polačik Matej
Published: December 2021

Intersexual differences in life span (age at death) and aging (increase in mortality risk associated with functional deterioration) are widespread among animals, from nematodes to humans. Males often live shorter than females, but there is substantial unexplained variation among species and populations. Despite extensive research, it is poorly understood how life span differences between the sexes are modulated by an interplay among genetic, environmental and social factors.

The goal of our study was to test how sex differences in life span and ageing are modulated by social and environmental factors, and by intrinsic differences between males and females.

To disentangle the complex basis of sex differences in life span and aging, we combined comparative data from sex ratios in 367 natural populations of four species of African annual killifish with experimental results on sex differences in life span and aging from eight laboratory populations tested in treatments that varied social and environmental conditions.

In the wild, females consistently outlived males. In captivity, sex‐specific mortality depended on social conditions. In social‐housed experimental groups, male‐biased mortality persisted in two aggressive species, but ceased in two placid species. When social and physical contacts were prevented by housing all fish individually, male‐biased mortality ceased in all four species. This outcome held across benign and challenging environmental conditions. Fitting demographic survival models revealed that increased baseline mortality was primarily responsible for a shorter male life span in social‐housing conditions. The timing and rate of aging were not different between the sexes. No marker of functional aging we recorded in our study (lipofuscin accumulation, proliferative changes in kidney and liver) differed between males and females, despite their previously confirmed association with functional aging in Nothobranchius killifish.

We show that sex differences in life span and aging in killifish are driven by a combination of social and environmental conditions, rather than differential functional aging. They are primarily linked to sexual selection but precipitated through multiple processes (predation, social interference). This demonstrates how sex‐specific mortality varies among species even within an ecologically and evolutionary discrete lineage and explains how external factors mediate this difference.
Regime shifts in a shallow lake over 12 years: Consequences for taxonomic and functional diversities, and ecosystem multifunctionality
Authors: Moi Dieison A. , Romero Gustavo Q. , Jeppesen Erik , Kratina Pavel , Alves Diego C. , Antiqueira Pablo A. P. , Teixeira de Mello Franco , Figueiredo Bruno R. S. , Bonecker Claudia C. , Pires Aliny P. F. , Braghin Louizi S. M. , Mormul Roger P.
Published: December 2021

Under increasing nutrient loading, shallow lakes may shift from a state of clear water dominated by submerged macrophytes to a turbid state dominated by phytoplankton or a shaded state dominated by floating macrophytes. How such regime shifts mediate the relationship between taxonomic and functional diversities (FD) and lake multifunctionality is poorly understood.

We employed a detailed database describing a shallow lake over a 12‐year period during which the lake has displayed all the three states (clear, turbid and shaded) to investigate how species richness, FD of fish and zooplankton, ecosystem multifunctionality and five individual ecosystem functions (nitrogen and phosphorus concentrations, standing fish biomass, algae production and light availability) differ among states. We also evaluated how the relationship between biodiversity (species richness and FD) and multifunctionality is affected by regime shifts.

We showed that species richness and the FD of fish and zooplankton were highest during the clear state. The clear state also maintained the highest values of multifunctionality as well as standing fish biomass production, algae biomass and light availability, whereas the turbid and shaded states had higher nutrient concentrations. Functional diversity was the best predictor of multifunctionality. The relationship between FD and multifunctionality was strongly positive during the clear state, but such relationship became flatter after the shift to the turbid or shaded state.

Our findings illustrate that focusing on functional traits may provide a more mechanistic understanding of how regime shifts affect biodiversity and the consequences for ecosystem functioning. Regime shifts towards a turbid or shaded state negatively affect the taxonomic diversity and FD of fish and zooplankton, which in turn impairs the multifunctionality of shallow lakes.
Connecting the Dots: Do Financial Analysts Help Corporate Boards Improve Corporate Social Responsibility?
Authors: Hussain Nazim , García‐Sánchez Isabel‐María , Khan Sana Akbar , Khan Zaheer , Martínez‐Ferrero Jennifer
Published: December 2021

This paper presents an examination of the joint impact of board structural elements at firm level and financial analysts as market‐level corporate governance (CG) on corporate social responsibility (CSR) performance. Our study contributes to the CG–CSR literature by adopting the bundling approach, a perspective that has recently attracted researchers’ attention as an answer to any heterogeneity and fragmentation in existing findings. It is based on an extensive sample consisting of 7,739 firm‐year observations of US firms for the 2006–2015 period. The findings suggest that financial analysts complement the corporate board with more independence, gender diversity and a specialized CSR committee to realize a certain level of CSR performance of a firm. The findings also indicate that analysts substitute for those internal governance factors that are associated with weaker boards – larger sizes and dual‐role CEOs. We also draw implications for research and practice from our findings.
‘It Was Necessary to Do Something With Those Women’: Colonial Governance and the ‘Disposal’ of Women and Girls in Early Nineteenth‐Century Sierra Leone
Authors: Ryan Maeve
Published: December 2021

The colonial archive offers comparatively few glimpses of the individual lives of enslaved African women and girls brought to Sierra Leone in the nineteenth century and ‘liberated’ under the terms of the British Abolition Act of 1807. This article sets out to do four things: first, to consider what colonial sources reveal about how women and girls experienced and responded to becoming ‘liberated Africans’, and to the ‘disposal’ practices of the Liberated African Department – including schooling, indenture and arranged marriages. Second, it considers what factors might have shaped those experiences. Third, it seeks to make a contribution to the literature on marriage in early colonial Africa by considering whether, and to what extent, British colonial policy towards liberated African women in Sierra Leone meets a modern definition of government‐led coerced or forced marriage. Finally, it evaluates the usefulness and limits of official archives, missionary records, court records and the accounts of self‐styled British Sierra Leone experts for studying the experiences of women and girls, and indicates potential avenues for further research.