bluuebunny/crossref_metadata_2025 huggingface dataset:
Electro-Metabolic Sensing Through Capillary ATP-Sensitive K+Channels and Adenosine to Control Cerebral Blood Flow
Authors: Sancho Maria , Klug Nicholas R. , Mughal Amreen , Heppner Thomas J. , Hill-Eubanks David , Nelson Mark. T.
Published: March 2021

The dense network of capillaries composed of capillary endothelial cells (cECs) and pericytes lies in close proximity to all neurons, ideally positioning it to sense neuro/glial-derived compounds that regulate regional and global cerebral perfusion. The membrane potential (VM) of vascular cells serves as the essential output in this scenario, linking brain activity to vascular function. The ATP-sensitive K+channel (KATP) is a key regulator of vascular VMin other beds, but whether brain capillaries possess functional KATPchannels remains unknown. Here, we demonstrate that brain capillary ECs and pericytes express KATPchannels that robustly control VM. We further show that the endogenous mediator adenosine acts through A2Areceptors and the Gs/cAMP/PKA pathway to activate capillary KATPchannels. Moreover, KATPchannel stimulationin vivocauses vasodilation and increases cerebral blood flow (CBF). These findings establish the presence of KATPchannels in cECs and pericytes and suggest their significant influence on CBF.

HIGHLIGHTS

Capillary network cellular components—endothelial cells and pericytes—possess functional KATPchannels.

Activation of KATPchannels causes profound hyperpolarization of capillary cell membranes.

Capillary KATPchannels are activated by exogenous adenosine via A2Areceptors and cAMP-dependent protein kinase.

KATPchannel activation by adenosine or synthetic openers increases cerebral blood flow.
DNA methylation is not a driver of gene expression reprogramming in young honey bee workers
Authors: Cardoso-Junior Carlos A. M. , Yagound Boris , Ronai Isobel , Remnant Emily J. , Hartfelder Klaus , Oldroyd Benjamin P.
Published: March 2021

Intragenic DNA methylation, also called gene body methylation, is an evolutionarily-conserved epigenetic mechanism in animals and plants. In social insects, gene body methylation is thought to contribute to behavioral plasticity, for example between foragers and nurse workers, by modulating gene expression. However, recent studies have suggested that the majority of DNA methylation is sequence-specific, and therefore cannot act as a flexible mediator between environmental cues and gene expression. To address this paradox, we examined whole-genome methylation patterns in the brains and ovaries of young honey bee workers that had been subjected to divergent social contexts: the presence or absence of the queen. Although these social contexts are known to bring about extreme changes in behavioral and reproductive traits through differential gene expression, we found no significant differences between the methylomes of workers from queenright and queenless colonies. In contrast, thousands of regions were differentially methylated between colonies, and these differences were not associated with differential gene expression in a subset of genes examined. Methylation patterns were highly similar between brain and ovary tissues and only differed in nine regions. These results strongly indicate that DNA methylation is not a driver of differential gene expression between tissues or behavioral morphs. Finally, despite the lack of difference in methylation patterns, queen presence affected the expression of all four DNA methyltransferase genes, suggesting that these enzymes have roles beyond DNA methylation. Therefore, the functional role of DNA methylation in social insect genomes remains an open question.
An extended DNA-free intranuclear compartment organizes centrosomal microtubules in Plasmodium falciparum
Authors: Simon Caroline S. , Funaya Charlotta , Bauer Johanna , Voß Yannik , Machado Marta , Penning Alexander , Klaschka Darius , Cyrklaff Marek , Kim Juyeop , Ganter Markus , Guizetti Julien
Published: March 2021

Rapid proliferation ofPlasmodium falciparumparasites in human red blood cells is the cause of malaria and is underpinned by an unconventional cell division mode, called schizogony. Contrary to model organisms,P. falciparumreplicates by multiple rounds of closed and asynchronous nuclear divisions that are not interrupted by cytokinesis. Organization and dynamics of the critical nuclear division factors are, however, poorly understood. Centriolar plaques, the centrosomes ofP. falciparum, are important regulators of division and serve as microtubule organizing centers. Early microscopy studies reveal an acentriolar, amorphous structure although its detailed organization remains elusive. Intranuclear microtubules mediate chromosome segregation, but the small size of parasite nuclei has precluded detailed analysis of their arrangement by classical fluorescence microscopy. We apply recently developed STED, expansion microscopy, and live cell imaging protocols to describe the reconfiguration of microtubules during schizogony. Analysis of centrin, nuclear pore, and microtubule positioning reveals a bipartite organization of the centriolar plaque. While centrin is extranuclear, we confirm by correlative light and electron tomography that microtubules are nucleated in a previously unknown and extended intranuclear compartment, which is devoid of chromatin. This study enables us to build a working model of the organization of an unconventional centrosome and better understand the diversity of eukaryotic cell division modes.
Can offsetting the energetic cost of hibernation restore an active season phenotype in grizzly bears (Ursus arctos horribilis)?
Authors: Jansen Heiko T. , Hutzenbiler Brandon Evans , Hapner Hannah R. , McPhee Madeline L. , Carnahan Anthony M. , Kelley Joanna L. , Saxton Michael W. , Robbins Charles T.
Published: March 2021

Hibernation is characterized by suppression of many physiological processes. To determine if this state is reversible in a non-food caching species, we fed hibernating grizzly bears (Ursus arctos horribilis) glucose for 10 days to replace 53% or 100% of the estimated minimum daily energetic cost of hibernation. Feeding caused serum concentrations of glycerol and ketones (ß-hydroxybutyrate) to return to active season levels irrespective of the amount of glucose fed. By contrast, free-fatty acids and indices of metabolic rate, such as general activity, heart rate, and strength of the daily heart rate rhythm and insulin sensitivity were restored to roughly 50% of active season levels. Body temperature was unaffected by feeding. To determine the contribution of adipose to these metabolic effects of glucose feeding we cultured bear adipocytes collected at the beginning and end of the feeding and performed metabolic flux analysis. We found a roughly 33% increase in energy metabolism after feeding. Moreover, basal metabolism before feeding was 40% lower in hibernation cells compared to fed cells or active cells cultured at 37°C, thereby confirming the temperature independence of metabolic rate. The partial suppression of circulating FFA with feeding likely explains the incomplete restoration of insulin sensitivity and other metabolic parameters in hibernating bears. Further suppression of metabolic function is likely an active process. Together, the results provide a highly controlled model to examine the relationship between nutrient availability and metabolism on the hibernation phenotype in bears.
Neural Networks for parameter estimation in microstructural MRI: a study with a high-dimensional diffusion-relaxation model of white matter microstructure
Authors: de Almeida Martins João P. , Nilsson Markus , Lampinen Björn , Palombo Marco , While Peter T. , Westin Carl-Fredrik , Szczepankiewicz Filip
Published: March 2021

Specific features of white-matter microstructure can be investigated by using biophysical models to interpret relaxation-diffusion MRI brain data. Although more intricate models have the potential to reveal more details of the tissue, they also incur time-consuming parameter estimation that may con-verge to inaccurate solutions due to a prevalence of local minima in a degenerate fitting landscape. Machine-learning fitting algorithms have been proposed to accelerate the parameter estimation and increase the robustness of the attained estimates. So far, learning-based fitting approaches have been restricted to lower-dimensional microstructural models where dense sets of training data are easy to generate. Moreover, the degree to which machine learning can alleviate the degeneracy problem is poorly understood. For conventional least-squares solvers, it has been shown that degeneracy can be avoided by acquisition with optimized relaxation-diffusion-correlation protocols that include tensor-valued diffusion encoding; whether machine-learning techniques can offset these acquisition require-ments remains to be tested. In this work, we employ deep neural networks to vastly accelerate the fitting of a recently introduced high-dimensional relaxation-diffusion model of tissue microstructure. We also develop strategies for assessing the accuracy and sensitivity of function fitting networks and use those strategies to explore the impact of acquisition protocol design on the performance of the network. The developed learning-based fitting pipelines were tested on relaxation-diffusion data acquired with optimized and sub-sampled acquisition protocols. We found no evidence that machine-learning algorithms can by themselves replace a careful design of the acquisition protocol or correct for a degenerate fitting landscape.
Reconstructing human early embryogenesis in vitro with pluripotent stem cells
Authors: Sozen Berna , Jorgensen Victoria , Zhu Meng , Cui Tongtong , Zernicka-Goetz Magdalena
Published: March 2021

Understanding human development is of fundamental biological and clinical importance. Yet despite its significance, insights into early developmental events in humans still remain largely unknown. While recent advances show that stem cells can mimic embryogenesis1–9to unravel hidden developmental mechanisms, a stem cell-based model of early human embryogenesis is lacking. Here, we use human extended pluripotent stem cells10to reconstitute early human development in 3-dimensions and recapitulate early embryo-like events. We first perform a systematic characterisation to reveal unique signalling requirements for building the human pre-implantation blastocyst. Further, we show that thesein vitrostem cell-derived blastocyst-like structures are able to undertake spatiotemporal self-organisation to mimic peri-implantation remodelling in which a polarised rosette opens up the amniotic cavity within a developing disc. The hallmarks of human early development displayed by this stem cell-basedin vitromodel mimics features of embryonic day 3 to day 9/10 of natural development. Thus, this platform represents a tractable model system to contribute to the basic understanding of cellular and molecular mechanisms governing early embryonic events in humans and to provide valuable insights into the design of differentiation protocols for human stem cells in clinical applications.
TMEM106B in humans and Vac7 and Tag1 in yeast are predicted to be lipid transfer proteins
Authors: Levine Tim P.
Published: March 2021

TMEM106B is an integral membrane protein of late endosomes and lysosomes involved in neuronal function, its over-expression being associated with familial frontotemporal lobar degeneration, and under-expression linked to hypomyelination. It has also been identified in multiple screens for host proteins required for productive SARS-CoV2 infection. Because standard approaches to understand TMEM106B at the sequence level find no homology to other proteins, it has remained a protein of unknown function. Here, the standard tool PSI-BLAST was used in a non-standard way to show that the lumenal portion of TMEM106B is a member of the LEA-2 domain superfamily. The non-standard tools (HMMER, HHpred and trRosetta) extended this to predict two yeast LEA-2 proteins in the lumenal domains of the degradative vacuole, equivalent to the lysosome: one in Vac7, a regulator of PI(3,5)P2production, and three in Tag1 which signals to terminate autophagy. Further analysis of previously unreported LEA-2 structures indicated that LEA-2 domains have a long, conserved lipid binding groove. This implies that TMEM106B, Vac7 and Tag1 may all be lipid transfer proteins in the lumen of late endocytic organelles.
Experience-related remapping of temporal encoding by striatal ensembles
Authors: Bruce R. Austin. , Weber Matthew A. , Volkman Rachael A. , Oya Mayu , Emmons Eric B. , Kim Youngcho , Narayanan Nandakumar S.
Published: March 2021

Temporal control of action is key for a broad range of behaviors and is disrupted in human diseases such as Parkinson’s disease and schizophrenia. A brain structure that is critical for temporal control is the dorsal striatum. Experience and learning can influence dorsal striatal neuronal activity, but it is unknown how these neurons change with experience in contexts which require precise temporal control of movement. We investigated this question by recording from medium-spiny neurons (MSNs) in the dorsal striatum of mice as they gained experience controlling their actions in time. We leveraged an interval timing task optimized for mice which required them to “switch” response ports after enough time had passed without receiving a reward. We report three main results. First, we found that time-related ramping activity and response-related activity increased with more experience. Second, temporal decoding by MSN ensembles improved with experience and was predominantly driven by time-related ramping activity. Finally, we found that some MSNs had differential modulation on error trials. These findings enhance our understanding of dorsal striatal temporal processing by demonstrating how MSN ensembles can evolve with experience. Our results can be linked to temporal habituation and illuminate striatal flexibility during interval timing, which may be relevant for human disease.
Antimalarials in mosquitoes overcomeAnophelesandPlasmodiumresistance to malaria control strategies
Authors: Paton Douglas G. , Probst Alexandra S. , Ma Erica , Adams Kelsey L. , Shaw W. Robert , Singh Naresh , Bopp Selina , Volkman Sarah K. , Hien Domombele F. S. , Paré Prislaure S. L. , Yerbanga Rakiswendé S. , Diabaté Abdoullaye , Dabiré Roch K. , Lefèvre Thierry , Wirth Dyann F. , Catteruccia Flaminia
Published: March 2021

The spread of insecticide resistance inAnophelesmosquitoes and drug resistance inPlasmodiumparasites is contributing to a global resurgence of malaria, making the generation of control tools that can overcome these issues an urgent public health priority. We recently showed that the transmission ofPlasmodium falciparumparasites can be efficiently blocked when exposingAnopheles gambiaefemales to antimalarials deposited on a treated surface, with no negative consequences on mosquito fitness. Here, we demonstrate this approach can overcome the hurdles of insecticide resistance in mosquitoes and drug resistant in parasites. We show that the transmission-blocking efficacy of mosquito-targeted antimalarials is maintained when field-derived, insecticide resistantAnophelesare exposed to the potent cytochrome b inhibitor atovaquone, demonstrating that this drug escapes insecticide resistance mechanisms that could potentially interfere with its function. Moreover, this approach prevents transmission of field-derived, artemisinin resistantP. falciparumparasites (Kelch13C580Y mutant), proving that this strategy could be used to prevent the spread of parasite mutations that induce resistance to front-line antimalarials. Atovaquone is also highly effective at limiting parasite development when ingested by mosquitoes in sugar solutions, including in ongoing infections. These data support the use of mosquito-targeted antimalarials as a promising tool to complement and extend the efficacy of current malaria control interventions.

Significance Statement

Effective control of malaria is hampered by resistance to vector-targeted insecticides and parasite-targeted drugs. This situation is exacerbated by a critical lack of chemical diversity in both interventions and, as such, new interventions are badly needed. Recent laboratory studies have shown that an alternative approach based on treatingAnophelesmosquitoes directly with antimalarial compounds can render the vector incapable of transmitting thePlasmodiumparasites that cause malaria. While promising, showing that mosquito-targeted antimalarials remain effective against wild parasites and mosquitoes, including drug- and insecticide-resistant populations, respectively, is crucial to the future viability of this approach. In this study, carried out in the US and Burkina Faso, we show that antimalarial exposure is highly effective, even against extremely resistant mosquitoes, and can block transmission of drug-resistant parasites. By combining lab, and field-based studies in this way we have demonstrated that this novel approach can be effective in areas where conventional control measures are no longer as effective.
Massively parallel reporter perturbation assay uncovers temporal regulatory architecture during neural differentiation
Authors: Kreimer Anat , Ashuach Tal , Inoue Fumitaka , Khodaverdian Alex , Yosef Nir , Ahituv Nadav
Published: March 2021

Gene regulatory elements play a key role in orchestrating gene expression during cellular differentiation, but what determines their function over time remains largely unknown. Here, we performed perturbation-based massively parallel reporter assays at seven early time points of neural differentiation to systematically characterize how regulatory elements and motifs within them guide cellular differentiation. By perturbing over 2,000 putative DNA binding motifs in active regulatory regions, we delineated four categories of functional elements, and observed that activity direction is mostly determined by the sequence itself, while the magnitude of effect depends on the cellular environment. We also find that fine-tuning transcription rates is often achieved by a combined activity of adjacent activating and repressing elements. Our work provides a blueprint for the sequence components needed to induce different transcriptional patterns in general and specifically during neural differentiation.
An Off-the-Shelf Bioadhesive Patch for Sutureless Repair of Gastrointestinal Defects
Authors: Wu Jingjing , Yuk Hyunwoo , Sarrafian Tiffany L. , Guo Chuanfei , Griffiths Leigh G. , Nabzdyk Christoph S. , Zhao Xuanhe
Published: March 2021

Surgical sealing and repair of injured and resected gastrointestinal (GI) organs are critical requirements for successful treatment and tissue healing. Despite being the standard of care, hand-sewn closure of GI defects using sutures faces various limitations and challenges. The process remains technically complicated and time-consuming. The needle-piercing and pointwise closure also inflict tissue damage and stress concentration, raising the risk of local failure and subsequent anastomotic leaks. To address these limitations and challenges, we introduce an off-the-shelf bioadhesive GI patch capable of atraumatic, rapid, robust, and sutureless repair of GI defects. The GI patch synergistically integrates a non-adhesive top layer and a dry bioadhesive bottom layer, resulting in a thin, flexible, transparent, and ready to use dressing with tissue-matching mechanical properties. Rapid, robust, and sutureless sealing capability of the GI patch is systematically characterized based on various standard tests inex vivoporcine GI organ models.In vitroandin vivorat models are utilized to validate biocompatibility and biodegradability of the GI patch including comprehensive cytotoxicity, histopathology, immunofluorescence, and blood analyses. To validate the GI patch’s efficacy in a clinically relevant setting, we demonstrate successful suturelessin vivosealing and healing of GI defects; namely in rat stomach and colon, and porcine colon injury models. The proposed GI patch not only provides a promising alternative to suture for repair of GI defects but also offers potential clinical opportunities in the treatment and repair of other organs.

One Sentence Summary

An off-the-shelf bioadhesive patch is introduced for facile sutureless repair of gastrointestinal defects, addressing various limitations of conventional suture-based treatments.
Differential regulation of mRNA fate by the human Ccr4-Not complex is driven by CDS composition and mRNA localisation
Authors: Gillen Sarah L. , Giacomelli Chiara , Hodge Kelly , Zanivan Sara , Bushell Martin , Wilczynska Ania
Published: March 2021

Background

Regulation of protein output at the level of translation allows for a rapid adaptation to dynamic changes to the cell’s requirements. This precise control of gene expression is achieved by complex and interlinked biochemical processes that modulate both the protein synthesis rate and stability of each individual mRNA. A major factor coordinating this regulation is the Ccr4-Not complex. Despite playing a role in most stages of the mRNA life cycle, no attempt has been made to take a global integrated view of how the Ccr4-Not complex affects gene expression.

Results

This study has taken a comprehensive approach to investigate post-transcriptional regulation mediated by the Ccr4-Not complex assessing steady-state mRNA levels, ribosome position, mRNA stability and protein production transcriptome-wide. Depletion of the scaffold protein CNOT1 results in a global upregulation of mRNA stability and the preferential stabilisation of mRNAs enriched for G/C-ending codons. We also uncover that mRNAs targeted to the ER for their translation have reduced translational efficiency when CNOT1 is depleted, specifically downstream of the signal sequence cleavage site. In contrast, translationally upregulated mRNAs are normally localised in p-bodies, contain disorder-promoting amino acids and encode nuclear localised proteins. Finally, we identify ribosome pause sites that are resolved or induced by the depletion of CNOT1.

Conclusion

We define the key mRNA features that determine how the human Ccr4-Not complex differentially regulates mRNA fate and protein synthesis through a mechanism linked to codon composition, amino acid usage, and mRNA localisation.
Stigma hurts: exploring employer and employee perceptions of tattoos and body piercings in Nigeria
Authors: Adisa Toyin Ajibade , Adekoya Olatunji David , Sani Kareem Folohunso
Published: March 2021

Purpose

This study draws on social stigma and prejudice to examine the perceptions and beliefs of managers and employees regarding visible tattoos and body piercings, as well as the impact they have on potential employment and human resource management in the global South, using Nigeria as the research context.

Design/methodology/approach

The study uses a qualitative research approach, drawing on data from 43 semi-structured interviews with employees and managers in Nigeria.

Findings

Contrary to the popular opinion that tattoos and body piercings are becoming more accepted and mainstream in society, this study finds that some Nigerian employers and employees may stigmatise and discriminate against people with visible tattoos and body piercings. The findings of this study suggest that beliefs about tattoos are predicated on ideologies as well as religious and sociocultural values, which then influence corporate values.

Research limitations/implications

The extent to which the findings of this research can be generalised is constrained by the limited sample and scope of the research.

Practical implications

Religious and sociocultural preconceptions about people with visible tattoos and body piercings have negative implications for the recruitment and employment of such people and could prevent organisations from hiring and keeping talented employees. This implies that talented employees might experience prejudice at job interviews, preventing them from gaining employment. Furthermore, stigmatising and discriminating against people with visible tattoos and body piercings may lead to the termination of employment of talented employees, which could negatively affect organisational productivity and growth.

Originality/value

This study provides an insight into the employment relations regarding tattoos and body piercing in Nigeria. The study highlights the need for mild beliefs and positive perceptions about people with visible tattoos and unconventional body piercings. There should be a general tolerance of the individual preference for body art and physical appearance, and this tolerance should be incorporated in organisational policies, which are enactments of corporate culture.
CMS at 13: a retrospective of the journey
Authors: Farrukh Muhammad , Raza Ali , Meng Fanchen , Wu Yihua
Published: March 2021

Purpose

To commemorate the 13th anniversary of the Chinese Management Studies (CMS) and suggest future research directions, this study aims to present an overview of the CMS through a systematic bibliometric analysis from 2007 to 2019. The analysis emphasizes the trend of themes, structure of publications and citations, the most cited publications, the most productive authors, universities, countries and regions.

Design/methodology/approach

The study uses the data extracted from the Scopus database to present an overview; besides, it also uses VOSviewer and Bibliometrix software packages to visualize the intellectual network of CMS.

Findings

This analysis is based on 486 publications between 2007 and 2019. Results show that there is a rising trend in the number of citations to CMS. The researchers from China were the most frequent contributors to the journal, whereas researchers from the USA, Taiwan, Singapore and Australia were well represented. In addition, the results show that innovation, leadership, human resource management and corporate social responsibility have been the most important research themes in the journal.

Practical implications

This study offers an objective view of the CMS publication structure. The study’s findings can help the journal readers obtain a quick snapshot of the leading trends occurring in the journal. Furthermore, this study provides future research directions for the journals by underscoring important themes.

Originality/value

As the journal’s first retrospective, this study not only educates and enriches CMS’ global readers and aspiring contributors but can also be useful to its editorial board, as it provides several inputs in the form of future research directions to guide the journal’s progress.
Restaurant failure in post-conflict Beirut: the macroenvironmental context and mismanagement
Authors: Yacoub Laurent , Nakhle Samer , Yahiaoui Dorra
Published: March 2021

Purpose

Given the complexity of a post-conflict environment, the restaurant sector needs to be analyzed not just from the economic perspective. This paper aims to identify the diverse macroenvironmental and managerial factors underlying restaurant failures in Lebanon. The authors hope that this effort may help increasing restaurant success rates in other post-conflict settings.

Design/methodology/approach

The aim of this paper is to explain how macroenvironmental pressures influence the restaurant business and which managerial factors are most critical in a post-conflict context. The authors adopted a qualitative method by conducting face-to-face, semi-structured interviews.

Findings

The findings show that restaurant failures in a competitive and uncertain post-conflict environment were caused mainly by a snowball of internal organizational factors related to bad management, poor human resource management policies, inefficiency and fraud. Internal organizational factors can all be associated with human mistakes and bad decisions, including excessive initial investment, expensive decoration, inability to manage monthly expenses, bad communication and market research.

Originality/value

This study contributes to the literature regarding restaurant failures in post-conflict regions and presents results that are expected to help managers in family- and non-family-owned businesses to enhance their decision-making process.
Examination of impact of COVID-19 on stock market: evidence from American peninsula
Authors: Amin Ali , Arshad Muhammad , Sultana Naheed , Raoof Rabeeya
Published: March 2021

Purpose

The rapid spread of COVID-19 has dramatic effects on financial market across the globe. This study analyzes the relationship between the COVID-19 cases, age and stock market indexes in Central America, North America, and South America.

Design/methodology/approach

The panel regression analysis on three regions from March 10, 2020 to April 9, 2020 was conducted to test the hypothesized model. The authors used Levin et al.’s (2002) panel data unit root test to check the stationarity, and Hausman (1978) test was applied to determine the random and fixed effects.

Findings

The authors’ panel regression results indicate that the COVID-19 cases have a negative impact on stock indexes, whereas the age has a positive impact on the stock indexes. The region-wise analysis supports the panel finding except for South America, which shows an insignificant association between stock indexes and COVID-19 cases.

Originality/value

The study supplements the literature by examining the impact of pandemics on stock indexes and focus on three multicultural regions, comprising developed, developing and emerging countries, which are hitherto unaddressed.
Mentoring and newcomer well-being: a socialization resources perspective
Authors: Cai Di , Liu Shengming , Liu Jia , Yao Li , Jia Xingze
Published: March 2021

Purpose

The purpose of this paper is to examine the effect of mentoring on newcomer well-being, as mediated by newcomer socialization and moderated by proactive personality.

Design/methodology/approach

Data were collected at four time points in a sample of 227 newcomers. Regression analysis and bootstrapping method were used to test the hypotheses.

Findings

Mentoring had a positive and indirect effect on newcomer well-being through socialization. The moderated mediation analysis also revealed that proactive personality augmented the direct effect of mentoring on socialization and its indirect effect on well-being.

Research limitations/implications

Our data were collected in China, thereby limiting the generalization of the research findings. Future research can test our model in different cultural contexts.

Practical implications

Organizations should consider establishing a mentoring program to foster newcomer socialization and achieve well-being. Within the mentoring context, cultivating newcomers to become more proactive can predict higher socialization levels, resulting in higher well-being.

Originality/value

Previous research largely focused on the development of the well-being of tenured employees. Drawing on socialization resources theory, this study focuses on the newcomer well-being and proposes the influential mechanism and boundary condition of the relationship between mentoring and newcomer well-being. It sheds light on exploring the well-being development for newcomers.
A network case of knowledge brokering
Authors: Rodway Joelle , MacGregor Stephen , Daly Alan , Liou Yi-Hwa , Yonezawa Susan , Pollock Mica
Published: March 2021

Purpose

The purpose of this paper is two-fold: (1) to offer a conceptual understanding of knowledge brokering from a sociometric point-of-view; and (2) to provide an empirical example of this conceptualization in an education context.

Design/methodology/approach

We use social network theory and analysis tools to explore knowledge exchange patterns among a group of teachers, instructional coaches and administrators who are collectively seeking to build increased capacity for effective mathematics instruction. We propose the concept of network activity to measure direct and indirect knowledge brokerage through the use of degree and betweenness centrality measures. Further, we propose network utility—measured by tie multiplexity—as a second key component of effective knowledge brokering.

Findings

Our findings suggest significant increases in both direct and indirect knowledge brokering activity across the network over time. Teachers, in particular, emerge as key knowledge brokers within this networked learning community. Importantly, there is also an increase in the number of resources exchanged through network relationships over time; the most active knowledge brokers in this social ecosystem are those individuals who are exchanging multiple forms of knowledge.

Originality/value

This study focuses on knowledge brokering as it presents itself in the relational patterns among educators within a social ecosystem. While it could be that formal organizational roles may encapsulate knowledge brokering across physical structures with an education system (e.g. between schools and central offices), these individuals are not necessarily the people who are most effectively brokering knowledge across actors within the broader social network.
Freshening increases the susceptibility to heat stress in intertidal mussels (Mytilus edulis) from the Arctic
Authors: Nielsen Martin B. , Vogensen Trine K. , Thyrring Jakob , Sørensen Jesper G. , Sejr Mikael K.
Published: March 2021

Temperatures in the Arctic are increasing at a faster pace than at lower latitudes resulting in range expansion of boreal species. In Greenland, the warming also drives accelerating melt of the Greenland Ice Sheet resulting in more meltwater entering Greenland fjords in summer.

Our aim was to determine if increasing summer temperatures combined with lower salinity can induce the expression of stress‐related proteins, for example, heat shock protein, in boreal intertidal mussels in Greenland, and whether low salinity reduces the upper thermal limit at which mortality occurs.

We conducted a mortality experiment, using 12 different combinations of salinity and air temperature treatments during a simulated tidal regime, and quantified the change in mRNA levels of five stress‐related genes (hsp24, hsp70, hsp90, sod and p38) in surviving mussels to discern the level of sublethal stress.

Heat‐induced mortality occurred in mussels exposed to an air temperature of 30°C and mortality was higher in treatments with lowered salinity (5 and 15‰), which confirms that low habitat salinity decreases the upper thermal limit of Mytilus edulis. The gene expression analysis supported the mortality results, with the highest gene expression found at combinations of high temperature and low salinity.

Combined with seasonal measurements of intertidal temperatures in Greenland, we suggest heat stress occurs in low salinity intertidal area, and that further lowered salinity in coastal water due to increased run‐off can make intertidal bivalves more susceptible to summer heat stress. This study thus provides an example of how different impacts of climate warming can work synergistically to stress marine organisms.
Disentangling the nonlinear effects of habitat complexity on functional responses
Authors: Mocq Julien , Soukup Pavel R. , Näslund Joacim , Boukal David S.
Published: March 2021

Structural complexity of habitats modifies trophic interactions by providing refuges and altering predator and prey behaviour. Nonlinear effects on trophic interaction strengths driven by these mechanisms may alter food web dynamics and community structure in response to habitat modifications. However, changes in functional response, the relationship between prey density and feeding rate, along habitat complexity (HC) gradients are little understood.

We quantified functional responses along a HC gradient from an entirely unstructured to highly structured habitat in a freshwater system, using dragonfly larvae (Aeshna cyanea) preying onChaoborus obscuripeslarvae. To disentangle mechanisms by which changes in HC affect functional responses, we used two different approaches—a population‐level and a behavioural experiment—applied an information theoretic approach to identify plausible links between HC and functional response parameters, and compared our results to previous studies.

Functional response shape did not change, but we found strong evidence for nonlinear dependence of attack rate and handling time on HC in our study. Combined results from both experiments imply that attack rate increased stepwise between the unstructured and structured habitats in line with the threshold hypothesis, because the predators gained better access to the prey. Handling time was lowest at an intermediate HC level in the population‐level experiment while the direct estimate of handling time did not vary with HC in the behavioural experiment. These differences point towards HC‐driven changes in foraging activity and other predator and prey behaviour.

Most previous studies reported stepwise decrease in attack rate in line with the threshold hypothesis or no change with increasing HC. Moreover, changes in the handling time parameter with HC appear to be relatively common but not conforming to the threshold hypothesis. Overall, increased HC appears to, respectively, weaken and strengthen trophic links in 2D and 3D predator–prey interactions.

We conclude that detailed understanding of HC effects on food webs requires complementary experimental approaches across HC gradients that consider predator foraging strategies and predator and prey behaviour. Such studies can also help guide conservation efforts as addition of structural elements is frequently used for restoration of degraded aquatic habitats.
Grow fast but don't die young: Maternal effects mediate life‐history trade‐offs of lizards under climate warming
Authors: Hao Xin , Zou Ting‐Ting , Han Xing‐Zhi , Zhang Fu‐Shun , Du Wei‐Guo
Published: March 2021

As postulated by life‐history theory, not all life‐history traits can be maximized simultaneously. In ectothermic animals, climate warming is predicted to increase growth rates, but at a cost to overall life span. Maternal effects are expected to mediate this life‐history trade‐off, but such effects have not yet been explicitly elucidated.

To understand maternal effects on the life‐history responses to climate warming in lizard offspring, we conducted a manipulative field experiment on a desert‐dwelling viviparous lacertid lizardEremias multiocellata, using open‐top chambers in a factorial design (maternal warm climate and maternal present climate treatments × offspring warm climate and offspring present climate treatments).

We found that the maternal warm climate treatment had little impact on the physiological and life‐history traits of adult females (i.e. metabolic rate, reproductive output, growth and survival). However, the offspring warm climate treatment significantly affected offspring growth, and both maternal and offspring warm climate treatments interacted to affect offspring survival.

Offspring from the warm climate treatment grew faster than those from the present climate treatment. However, the offspring warm climate treatment significantly decreased the survival rate of offspring from maternal present climate treatment, but not for those from the maternal warm climate treatment.

Our study demonstrates that maternal effects mediate the trade‐off between growth and survival of offspring lizards, allowing them to grow fast without a concurrent cost of low survival rate (short life span). These findings stress the importance of adaptive maternal effects in buffering the impact of climate warming on organisms, which may help us to accurately predict the vulnerability of populations and species to future warming climates.
Lianas have more acquisitive traits than trees in a dry but not in a wet forest
Authors: Medina‐Vega José A. , Bongers Frans , Poorter Lourens , Schnitzer Stefan A. , Sterck Frank J.
Published: March 2021

Lianas are increasing in relative abundance and biomass in many tropical forests. We tested the hypothesis that lianas conform to the fast and acquisitive end of the continuum of plant strategies, allowing lianas to acquire resources faster than trees.

We assessed functional traits representative of the leaf (LES) and wood economics spectrum (WES), including plant hydraulics, in 16 liana and 16 tree species in the canopy of two tropical forests at the extremes of the climatic and geological gradient across the Isthmus of Panama.

For both forests, we observed a trade‐off between the construction of more productive leaves with rapid turnover and expensive leaves with slower turnover. We also found trait variation associated with wood and hydraulic traits. These two axes were orthogonal, suggesting that trade‐offs at the leaf and stem, including plant hydraulics, operate independently.

For the dry forest, lianas had cheaper and more efficient leaves than trees. For the wet forest, lianas and trees overlapped in leaf and stem characteristics. Moreover, the duration of green foliage highly explained the variation between dry forest species, reflecting different adaptations to drought. In the wet forest, fast‐growing species benefited from a higher return on investments of leaf vascular tissues than slow‐growing species and they had a higher capacity to transport water through the leaf.

A higher capacity to construct more productive leaves and display leaves with lower costs may favour lianas over trees in light interception, photosynthetic rates, and growth under high light and nutrient availability in dry forests.

Synthesis. Lianas in a dry tropical forest had a more acquisitive strategy than trees, characterized by more productive leaves and more efficient display for light interception. In dry environments, lianas appear to benefit from high‐light and nutrient‐rich soils and thus take advantage of higher resource conditions compared to trees. By contrast, in a wet tropical forest, lianas and trees overlapped in leaf and stem characteristics and lianas were not more acquisitive than trees. In wet environments, low light availability and nutrient‐poor soils in a context of low water limitation may constrain variation in resource acquisition strategies between lianas and trees.
Effects of pigment richness and size variation on coexistence, richness and function in light‐limited phytoplankton
Authors: Spaak Jurg Werner , De Laender Frederik
Published: March 2021

Trait diversity is traditionally seen as promoting species richness and ecosystem function. Species with dissimilar traits would partition available resources, increasing niche differences, facilitating coexistence and increasing ecosystem function.

Here we first show, using theory and simulations for light‐limited phytoplankton, that combing photosynthetic pigments is indeed a necessary condition for coexistence and stimulates ecosystem function.

However, pigment richness does mostly not permit the coexistence of more than two species, and increases productivity at most 40% compared to single‐pigment communities. That is because blending in more pigments leads to coexistence of species with many pigments and therefore flat absorption spectra, which equalizes their fitness but decreases their niche differences. Similarly, seeding species with more variable size leads to an excess of large‐celled species, which does not only decrease fitness differences but also niche differences.

Empirical data and additional simulations suggest that pigment richness effects can be stronger during transient dynamics but inevitably weaken with time, that is, pigment richness effects on species richness and function are likely short‐lived.

Synthesis. Our results highlight the need to apply coexistence theory to understand the long‐term effects of trait diversity on biodiversity and ecosystem function.
What is in a name? Autonomic imbalance and medically unexplained symptoms in Taiwan
Authors: Chen Jia‐shin
Published: March 2021

Medically unexplained symptoms (MUS) are persistent bodily symptoms without known pathology. An unofficial term has recently emerged in Taiwan to accommodate MUS: autonomic imbalance (AI). AI literally refers to disturbances of the autonomic nervous system (ANS) that innervates vital organs. However, AI is variously conceptualised by different parties. This study intends to investigate what is in the name of AI. It draws on available databases and in‐depth interviews with AI sufferers and Western and Chinese medicine physicians. Some physicians research ANS functions through heart rate variability measurements. Research findings show that physicians regard AI as a convenient term for clinical communication and a euphemistic substitute for MUS or even psychiatric diagnoses. It is not a ‘real thing’. However, AI sufferers treat AI as a bona fide disease, only that it has not been officially classified. AI is therefore an unfaithful translation, or an uncontrolled equivocation, of MUS. The paper concludes by discussing the implications of treating AI as an equivocation. These implications include the limitations of the current diagnostic criteria, the necessity to rethink the dichotomy of mind and body, and the underlying realities exposed or masked by ‘diagnosis’.
The datafication of nature: data formations and new scales in natural history
Authors: Nadim Tahani
Published: March 2021

In this essay, I consider the scales and connections lost and gained as natural history adopts digital data infrastructures. On the basis of ongoing work in the Museum für Naturkunde Berlin, I track the relations between insect specimens and their material and digital informational ecologies. Using Latour's notion of the ‘circulating reference’, I follow the insect specimens as they make their way into taxonomies, databases, and digitization apparatuses. In focusing on human‐data mediations in museum practices of ordering, describing, and distributing specimens, I show how the datafication of nature makes present conventionally dissociated contexts, including German colonialism. Proposing the concept of a data formation, I suggest that ethnographers have much to contribute in bringing forward the sociocultural and historical specificities and contingencies within data.
Data – ova – gene – data
Authors: Walford Antonia
Published: March 2021

In this essay, I observe that data is valuable not only for what it is, but also for what it will become: that is, that data is a form of potential. I explore two aspects of this by drawing two comparisons with other forms of potential: ova and genes. First, building on ethnographic fieldwork with environmental scientists and technicians in the Brazilian Amazon, I compare data processing with ova donation in the United Kingdom in order to explore how data processing might be considered a form of reproductive labour. I then turn to emergent big data infrastructures in the environmental sciences, and compare the environmental sciences with genomics, in order to gesture towards some critical questions that need to be asked of such open data initiatives. I end with a reflection on comparison as a privileged means of drawing out the forms understood to be latent within data.