bluuebunny/crossref_metadata_2025 huggingface dataset:
Nanoscopic Structural Fluctuations of Disassembling Microtubules Revealed by Label-Free Super-Resolution Microscopy
Authors: Vala Milan , Bujak Łukasz , Marín Antonio García , Holanová Kristýna , Henrichs Verena , Braun Marcus , Lánský Zdeněk , Piliarik Marek
Published: October 2020

Microtubules are cytoskeletal polymers of tubulin dimers assembled into protofilaments that constitute nanotubes undergoing periods of assembly and disassembly. Static electron micrographs suggest a structural transition of straight protofilaments into curved ones occurring at the tips of disassembling microtubules. However, these structural transitions have never been observed and the process of microtubule disassembly thus remains unclear. Here, a label-free optical microscopy capable of selective imaging of the transient structural changes of protofilaments at the tip of a disassembling microtubule is introduced. Upon induced disassembly, the transition of ordered protofilaments into a disordered conformation is resolved at the tip of the microtubule. Imaging the unbinding of individual tubulin oligomers from the microtubule tip reveals transient pauses and relapses in the disassembly, concurrent with enrichment of ordered protofilament segments at the microtubule tip. These findings show that microtubule disassembly is a discrete process and suggest a mechanism of switching from the disassembly to the assembly phase.
GWAS analysis combined with QTL mapping identifyCPT3andABHas genes underlying dolichol accumulation in Arabidopsis
Authors: Gawarecka Katarzyna , Siwinska Joanna , Poznanski Jaroslaw , Onysk Agnieszka , Surowiecki Przemyslaw , Surmacz Liliana , Ahn Ji Hoon , Korte Arthur , Swiezewska Ewa , Ihnatowicz Anna
Published: October 2020

Dolichols (Dols), ubiquitous components of living organisms, are indispensable for cell survival. In plants, as well as other eukaryotes, Dols are crucial for posttranslational protein glycosylation, aberration of which leads to fatal metabolic disorders in humans. Until now, the regulatory mechanisms underlying Dol accumulation remain elusive. In this report, we have analyzed the natural variation of the accumulation of Dols and six other isoprenoids between 120Arabidopsis thalianaaccessions. Subsequently, by combining QTL and GWAS approaches, we have identified several candidate genes involved in the accumulation of Dols, polyprenols, plastoquinone, and phytosterols. The role of two genes implicated in the accumulation of major Dols in Arabidopsis – the AT2G17570 gene encoding a long searched forcis-prenyltransferase (CPT3) and the AT1G52460 gene encoding an alpha-beta hydrolase (ABH) – is experimentally confirmed. These data will help to generate Dol-enriched plants which might serve as a remedy for Dol-deficiency in humans.
Epistasis shapes the fitness landscape of an allosteric specificity switch
Authors: Nishikawa Kyle K. , Hoppe Nicholas , Smith Robert , Bingman Craig , Raman Srivatsan
Published: October 2020

Epistasis is a major determinant in the emergence of novel protein function. In allosteric proteins, direct interactions between inducer-binding mutations propagate through the allosteric network, manifesting as epistasis at the level of biological function. Elucidating this relationship between local interactions and their global effects is essential to understanding evolution of allosteric proteins. We integrate computational design, structural and biophysical analysis to characterize the emergence of novel inducer specificity in an allosteric transcription factor. Adaptive landscapes of different inducers of the engineered mutant show that a few strong epistatic interactions constrain the number of viable sequence pathways, revealing ridges in the fitness landscape leading to new specificity. Crystallographic evidence shows a single mutation drives specificity by reshaping the binding pocket. Comparison of biophysical and functional landscapes emphasizes the nonlinear relationship between local inducer affinity and global function (allostery). Our results highlight the functional and evolutionary complexity of allosteric proteins.
Biochemical Validation of a Fourth Guanidine Riboswitch Class in Bacteria
Authors: Salvail Hubert , Balaji Aparaajita , Yu Diane , Roth Adam , Breaker Ronald R.
Published: October 2020

An intriguing consequence of ongoing riboswitch discovery efforts is the occasional identification of metabolic or toxicity response pathways for unusual ligands. Recently, we reported the experimental validation of three distinct bacterial riboswitch classes that regulate gene expression in response to the selective binding of a guanidinium ion. These riboswitch classes, called guanidine-I, -II and -III, regulate numerous genes whose protein products include previously misannotated guanidine exporters and enzymes that degrade guanidine via an initial carboxylation reaction. Guanidine is now recognized as the primal substrate of many multidrug efflux pumps that are important for bacterial resistance to certain antibiotics. Guanidine carboxylase enzymes had long been annotated as urea carboxylase enzymes but are now understood to participate in guanidine degradation. Herein we report the existence of a fourth riboswitch class for this ligand, called “guanidine-IV”. Members of this class use a novel aptamer to selectively bind guanidine and use an unusual expression platform arrangement that is predicted to activate gene expression when ligand is present. The wide distribution of this abundant riboswitch class, coupled with the striking diversity of other guanidine-sensing RNAs, demonstrates that many bacterial species maintain sophisticated sensory and genetic mechanisms to avoid guanidine toxicity. This finding further highlights the mystery regarding the natural source of this nitrogen-rich chemical moiety.
Molecular determinants for α-tubulin methylation by SETD2
Authors: Kearns Sarah , Mason Frank M. , Rathmell W. Kimryn , Park In Young , Walker Cheryl , Verhey Kristen , Cianfrocco Michael A.
Published: October 2020

Post-translational modifications to tubulin are important for many microtubule-based functions inside cells. A recently identified tubulin modification, methylation, occurs on mitotic spindle microtubules during cell division, and is enzymatically added to tubulin by the histone methyltransferase SETD2. We used a truncated version of human SETD2 (tSETD2) containing the catalytic SET and C-terminal Set2 Rpb1 interacting (SRI) domains to investigate the biochemical mechanism of tubulin methylation. We found that recombinant tSETD2 has a higher activity towards tubulin dimers than polymerized microtubules. Using recombinant single-isotype tubulin, we demonstrate that methylation is restricted to lysine 40 (K40) of α-tubulin. We then introduced pathogenic mutations into tSETD2 to probe the recognition of histone and tubulin substrates. A mutation in the catalytic domain, R1625C, bound to tubulin but could not methylate it whereas a mutation in the SRI domain, R2510H, caused loss of both tubulin binding and methylation. We thus further probed a role for the SRI domain in substrate binding and found that mutations within this region had differential effects on the ability of tSETD2 to bind to tubulin versus RNA Polymerase II substrates, suggesting distinct mechanisms for tubulin and histone methylation by SETD2. Lastly, we found that substrate recognition also requires the negatively-charged C-terminal tail of α-tubulin. Together, this work provides a framework for understanding how SETD2 serves as a dual methyltransferase for histone and tubulin methylation.
Structural basis of inhibition of a putative drug efflux transporter NorC, through a single-domain camelid antibody
Authors: Kumar Sushant , Athreya Arunabh , Gulati Ashutosh , Nair Rahul Mony , Penmatsa Aravind
Published: October 2020

Multi-drug efflux is a major mechanism of acquiring antimicrobial resistance among superbugs. In this study, we report the X-ray structure of NorC, a 14 transmembrane major facilitator superfamily member that is implicated in fluoroquinolone resistance in drug-resistantStaphylococcus aureusstrains, at a resolution of 3.6 Å. The NorC structure was determined in complex with a single-domain camelid antibody that interacts at the extracellular face of the transporter and stabilizes it in an outward-open conformation. The complementarity determining regions of the antibody enter and block solvent access to the interior of the vestibule, thereby inhibiting alternating-access. NorC specifically interacts with an organic cation, tetraphenylphosphonium, although it does not demonstrate an ability to transport it. The interaction is compromised in the presence of NorC-antibody complex, consequently establishing a strategy to detect and block NorC and related efflux pumps through the use of single- domain camelid antibodies.
Yeast Ssd1 is a non-enzymatic member of the RNase II family with an alternative RNA recognition interface
Authors: Bayne Rosemary A. , Jayachandran Uma , Kasprowicz Aleksandra , Bresson Stefan , Tollervey David , Wallace Edward W. J. , Cook Atlanta G.
Published: October 2020

The conserved fungal RNA binding protein Ssd1, is important in stress responses, cell division and virulence. Ssd1 is closely related to Dis3L2 of the RNase II family of nucleases, but lacks catalytic activity and may act by suppressing translation of associated mRNAs. Previous studies identified motifs that are enriched in Ssd1-associated transcripts, yet the sequence requirements for Ssd1 binding are not well understood. Here we present the crystal structure of Ssd1 at 1.9 Å resolution. Active RNase II enzymes have a characteristic, internal RNA binding path, but in Ssd1 this is blocked by remnants of regulatory sequences. Instead, RNA binding activity has likely been relocated to the outer surface of the protein. Usingin vivocrosslinking and cDNA analysis (CRAC), we identify Ssd1-RNA binding sites. These are strongly enriched in 5’UTRs of a subset of mRNAs encoding cell wall proteins. Based on these and previous analyses, we identified a conserved bipartite motif that binds Ssd1 with high affinityin vitro. These studies provide a new framework for understanding the function of a pleiotropic post-transcriptional regulator of gene expression and give insights into the evolution of regulatory elements in the RNase II family.
Fluorescent tagging ofPlasmodiumcircumsporozoite protein allows imaging of sporozoite formation but blocks egress from oocysts
Authors: Singer Mirko , Frischknecht Friedrich
Published: October 2020

The circumsporozoite protein, CSP is the major surface protein ofPlasmodiumsporozoites, the form of malaria parasites transmitted by mosquitoes. CSP is involved in sporozoite formation within and egress from oocysts, entry into mosquito salivary glands and mammalian liver as well as migration in the skin. Antibodies against CSP can stop infection prior to the first round of parasite replication in the liver. CSP consists of different domains and is proteolytically cleaved prior to hepatocyte invasion. Part of CSP has been developed into a licensed vaccine against malaria. Yet, how CSP facilitates sporozoite formation, oocyst egress and hepatocyte specific invasion is still not fully understood. Here, we generated a series of parasites expressing full-length versions of CSP as fusion proteins with the green fluorescent protein. This enabled the investigation of sporozoite formation in living oocysts and revealed a dominant negative function of some GFP-CSP fusions during sporozoite egress.
Characterization of potassium, sodium and their interactions effects in yeasts
Authors: Illarionov Aleksandr , Lahtvee Petri-Jaan , Kumar Rahul
Published: October 2020

Biotechnology requires efficient microbial cell factories. The budding yeastSaccharomyces cerevisiaeis an important cell factory but for a sustainable use of natural resources more diverse cellular attributes are essential. Here, we benchmarked non-conventional yeastsKluyveromyces marxianus(KM) andRhodotorula toruloides(RT) against the extensively characterized strains ofS. cerevisiae, CEN.PK and W303. We developed a computational method for the characterization of cell/vacuole volumes and observed an inverse relationship between the maximal growth rate and the median cell volume that was responsive to monovalent cations. We found that the supplementation of certain K+concentrations to CEN.PK cultures containing 1.0 M Na+increased the specific growth rate by four-fold with a parabolic shift in the median cell/vacuole volumes. The impairment of ethanol and acetate utilization in CEN.PK, acetate in W303, at the higher K+/Na+concentrations implied an interference in the metabolic pathways required for their consumption. In RT cultures, the supplementation of K+/Na+induced a trade-off in glucose utilization but alleviated cellular aggregates formation where specified cationic concentrations increased the beta-carotene yield by 60% compared with the reference. Our comparative analysis of cell/vacuole volumes using exponential phase cultures showed that the median volumes decreased the most for KM and the least for RT in response to studied cations. Noteworthy for the implication in aging research using yeasts, the vacuole to cell volume ratio increased with the increase in cell volume for W303 and KM, but not for CEN.PK and RT.

Importance

For designing efficient bioprocesses characterization of microbial cell factories in the relevant culture environment is important. The control of cell volume in response to salt stress is crucial for the productivity of microbial cell factories. We developed an open source computational method for the analysis of optical microscopy images that allowed us to quantify changes in cell/vacuole volumes in response to common salts in yeasts. Our study provides a framework for appreciating the role of cellular/organellar volumes in response to changing physiological environment. Our analysis showed that K+/Na+interactions could be used for improving the cellular fitness of CEN.PK and increasing the productivity of beta-carotene inR. toruloides, which is a commercially important antioxidant and a valuable additive in foods.
Sequencing identifies multiple early introductions of SARS-CoV-2 to the New York City region
Authors: Maurano Matthew T. , Ramaswami Sitharam , Zappile Paul , Dimartino Dacia , Boytard Ludovic , Ribeiro-dos-Santos André M. , Vulpescu Nicholas A. , Westby Gael , Shen Guomiao , Feng Xiaojun , Hogan Megan S. , Ragonnet-Cronin Manon , Geidelberg Lily , Marier Christian , Meyn Peter , Zhang Yutong , Cadley John , Ordoñez Raquel , Luther Raven , Huang Emily , Guzman Emily , Arguelles-Grande Carolina , Argyropoulos Kimon V. , Black Margaret , Serrano Antonio , Call Melissa E. , Kim Min Jae , Belovarac Brendan , Gindin Tatyana , Lytle Andrew , Pinnell Jared , Vougiouklakis Theodore , Chen John , Lin Lawrence H. , Rapkiewicz Amy , Raabe Vanessa , Samanovic Marie I. , Jour George , Osman Iman , Aguero-Rosenfeld Maria , Mulligan Mark J. , Volz Erik M. , Cotzia Paolo , Snuderl Matija , Heguy Adriana
Published: October 2020

Effective public response to a pandemic relies upon accurate measurement of the extent and dynamics of an outbreak. Viral genome sequencing has emerged as a powerful approach to link seemingly unrelated cases, and large-scale sequencing surveillance can inform on critical epidemiological parameters. Here, we report the analysis of 864 SARS-CoV-2 sequences from cases in the New York City metropolitan area during the COVID-19 outbreak in spring 2020. The majority of cases had no recent travel history or known exposure, and genetically linked cases were spread throughout the region. Comparison to global viral sequences showed that early transmission was most linked to cases from Europe. Our data are consistent with numerous seeds from multiple sources and a prolonged period of unrecognized community spreading. This work highlights the complementary role of genomic surveillance in addition to traditional epidemiological indicators.
Lowest emission sustainable aviation biofuels as the potential replacement for the Jet-A fuels
Authors: A. Anderson , A. Karthikeyan , C. Ramesh Kumar , S. Ramachandran , T.R. Praveenkumar
Published: October 2020

Purpose

The purpose of this study is to predict the performance and emission characteristics of micro gas turbine engines powered by alternate fuels. The micro gas turbine engine performance, combustion and emission characteristics are analyzed for the jet fuel with different additives.

Design/methodology/approach

The experimental investigation was carried out with Jet A-1 fuel on the gas turbine engines at different load conditions. The primary blends of the Jet A-1 fuels are from canola and solid waste pyrolysis oil. Then the ultrasonication of highly concentrated multiwall carbon nanotubes is carried with the primary blends of canola (Jet-A fuel 70%, canola 20% and 10% ethanol) and P20E (Jet-A 70% fuel, 20% PO and 10% ethanol).

Findings

The consumption of the fuel is appreciable with the blends at a very high static thrust. The 39% reduction in thrust specific fuel consumption associated with a 32% enhance in static thrust with P20E blend among different fuel blends. Moreover, due to the increase in ethanol concentration in the blends PO20E and C20E lead to a 22% rise in thermal efficiency and a 9% increase in higher oxygen content is observed.

Practical implications

The gas turbine engine emits very low emission of gases such as CO, CO2 and NOx by using the fuel blends, which typically reduces the fossil fuel usage limits with reduced pollutants.

Originality/value

The emission of the gas turbine engines is further optimized with the addition of hydrogen in Jet-A fuel. That is leading to high specific fuel exergy and owing to the lower carbon content in the hydrogen fuel when compared with that of the fossil fuels used in gas turbine engines. Therefore, the usage of hydrogen with nanofluids was so promising based on the results obtained for replacing fossil fuels.
Flavonoid enrichment of fresh-cut apple through osmotic dehydration-assisted impregnation
Authors: Lopez Ma. Michelle L. , Morais Rui M.S.C. , Morais Alcina M.M.B.
Published: October 2020

Purpose

Inclusion of bioactive compounds in food products is promising for developing novel functional food products. The feasibility of incorporating flavonoids and low-calorie sugar substitutes in fresh-cut apple through osmotic dehydration (OD) was investigated.

Design/methodology/approach

The impregnation of quercetin and fisetin in apple cubes was tested. The effects of different osmotic agents, sucrose and sorbitol:mannose, on the water loss (WL) and sugar gain of the samples were studied at 25 and 40 °C for eight hours.

Findings

Temperature was a significant factor in the mass transfer kinetics, that is to say, higher temperatures resulting in higher rates. The molecular weight of the solutes in the osmotic solution also affected the OD kinetics and flavonoids uptake, as well as the physico-chemical quality.

Originality/value

Overall, the results indicate that OD using alternative low-calorie and health-promoting solutes can be an effective treatment to simultaneously enrich fresh-cut apples with senolytic flavonoids, therefore presenting a great potential for a novel functional food product.
Technological innovation research in the last six decades: a bibliometric analysis
Authors: Akbari Morteza , Khodayari Maryam , Khaleghi Armin , Danesh Mozhgan , Padash Hamid
Published: October 2020

Purpose

This study aims to explore the evolutionary trajectories of technological innovation using 1,361 documents to determine the most cited documents, influential authors, prominent journals and leading countries in the field of technological innovation research.

Design/methodology/approach

In this paper, the intellectual structure of technological innovation literature was studied using bibliometric co-occurrence and co-citation analyses. The authors focused on the 1,361 documents in this research stream published between 1961 and 2019.

Findings

The findings show that researchers do not appropriately draw on theoretical perspectives external to the field to study different dimensions of technological innovation. This study reveals six distinct areas within the literature: sources of innovation, environmental innovation and technological innovation, investment, economic growth of countries, technological innovation systems for sustainable development, innovation system, research and development and competitiveness.

Originality/value

This study investigates the foundations of the conception, themes and research communities within the technological innovation domain. This paper found strong evidence that technological innovation is one of the keys to the research area in innovation studies.
Methods in assessing the values of architecture in residential neighbourhoods
Authors: Spoormans Lidwine , Pereira Roders Ana
Published: October 2020

Purpose

Although residential neighbourhoods are the largest and most resilient share of a city and the process of urban conservation and renewal is ongoing, methods to assess their values are limited. This paper presents the results of a systematic literature review, revealing the state of the art and its knowledge gaps with regard to methods for assessing values of architecture in residential neighbourhoods.

Design/methodology/approach

The systematic literature review is based on studies selected by a research protocol, using a digital database of peer-reviewed literature. A metanarrative approach is used to synthesise the qualitative data from reviewed articles. This review has two stages: (1) giving an overview of the field and (2) categorising research methods and disciplines.

Findings

The review revealed a wide variety of studies from different disciplines and deduced its key trends, titled as “storylines”, concerning the methods to assess significance, integrating a broader scope of values and different perspectives. In particular, the “storylines” outside traditional heritage disciplines offer methods to include more stakeholders, link value assessment to policy development or highlight heritage potential. Results reveal the diversity in concepts and strengthen the need for an interdisciplinary vocabulary on values and methods, enabling planners and policymakers to compare their results and help to create more attractive and resilient cities.

Originality/value

By reviewing and comparing the selected studies from a wider range of disciplines and research fields, this paper shares insights into the complementary characteristics of the different types of value research, outlining the added value of the different perspectives.
Satisfying consumers all around: a multidisciplinary view of omnichannel retail
Authors: Wang Juan , Zheng Bowen , Liu Hefu
Published: October 2020

Purpose

Omnichannel retail are catching increasing attention from multiple research area, due to its widespread and essential application in retailing industry. The principal object of this paper is to systematically review current studies on omnichannel retail in information systems, operations and marketing research area. Further, the second purpose of this study is to provide insights and guides on omnichannel research to facilitate advance research in the area.

Design/methodology/approach

A systematic review on omnichannel retail in retailing industry has been conducted. 33 research articles from 2014 to 2020 from Financial Times 50 journals (FT 50 journals) were identified to be reviewed. The articles were reviewed on the basis of study area namely: information systems, operations and marketing. These research areas were further divided into subcategories to provide in-depth and crystal clear review of literature.

Findings

The review outcome showed that omnichannel topics are active in management studies. There are three main research areas: information systems, operations management and marketing. This study found that IT enhances channel capabilities and expands demand in omnichannel retail; operations can be better optimized based on understanding of cross-channel interactions, product category and retailer types; consumer heterogeneity, product category, channel capabilities and retailer type are all found to contribute to complexities of omnichannel marketing.

Originality/value

This study provides a pioneering review to gauge the updated literature concerned with omnichannel research in terms of IT, operations and marketing perspective. Further, a systematic literature review provides insights and guides for future significant studies on potential research subjects.
An empirical study of the influence of individual-related factors on undergraduates' academic burnout: Malaysian context
Authors: Lau Sook Cheng , Chow Hon Jie , Wong Siew Chin , Lim Chui Seong
Published: October 2020

Purpose

The purpose of this study is to examine the relationship between perfectionism, self-efficacy, coping strategies and academic burnout among Malaysian undergraduates in higher education institutions.

Design/methodology/approach

Data were collected from 251 respondents who were public and private university undergraduates. Partial least square structural equation modelling (PLS-SEM) was used to investigate the influences of coping strategies, perfectionism and self-efficacy on academic burnout among undergraduates.

Findings

The results showed that all independent variables, namely coping strategies, perfectionism and self-efficacy are statistically correlated to academic burnout.

Research limitations/implications

This article provides an empirical framework for explaining the academic burnout of undergraduates’ based on the review of related career works of literature.

Practical implications

To provide insights in order to improve understanding of existing stress models and provide practical implications for local higher education institutions and undergraduates to reduce academic burnout.

Social implications

The study seeks to enhance awareness and destigmatise the mental health issues of undergraduates, which is important to help them to maintain a healthy lifestyle and well-being.

Originality/value

This paper offers new insight to identify the predictors of academic burnout among undergraduates from Malaysian higher education institutions.
Does terrorism hamper FDI inflows? A pre and post 9/11 analysis
Authors: Arif Imtiaz , Rawat Amna Sohail , Khan Lubna
Published: October 2020

Purpose

This research intends to determine the role of terrorism in defying foreign direct investment (FDI) in top terror effected economies.

Design/methodology/approach

Panel data on FDI and terrorism from top terror effected economies spanning from 1987 to 2018 were used and the relationship for whole sample was investigated. Later the sample period was divided into pre (1987–2001) and post 9/11 (2002–2018) subsample and same relationship was tested to investigate the normalization of terror effect on FDI. The method of Pooled Mean Group (PMG) was used to test the hypothesis.

Findings

The results showed a negative but statistically insignificant impact of terrorism on the FDI inflows in the long run. Later the sample period was divided into pre (1987–2001) and post 9/11 (2002–2018) subsample. The empirical estimates for pre and post 9/11 periods indicated a negative and statistically significant relationship between terrorism and FDI for pre 9/11 period, and a negative but statistically insignificant relationship between the two variables for post 9/11 period.

Originality/value

The findings suggest several important policy implications for the terror affected countries and are further discussed in the study.
Human resource management adaptation among family firms operating in Western Australia: an exploratory study
Authors: O'Shea Michelle , Duarte Alonso Abel
Published: October 2020

Purpose

Interviews were conducted with eight family businesses involved in several industries in Western Australia.

Design/methodology/approach

The purpose of this study is to draw on the experiences of family-owned firms and explore how contemporary human resource management (HRM) and allied developments shape their business practices.

Findings

Significant strengths emerged relevant to “formalised HRM processes” and “familiness”. However, challenges were simultaneously experienced or interpreted as negatively affecting family firm performance. In addition, there was a relationship between challenges and external environmental factors. These challenges are categorised as “labour costs and supply” and “formalising HRM practices”. Further, participants discussed emerging opportunities, and how they were strategically considering the relationship between organisation finance, innovation, future growth, operations and HRM.

Originality/value

From a practical standpoint, the research addresses the complexities of managing contemporary HRM developments in ways that contribute to improved family firm performance. From a theoretical perspective, key insights of the resource-based view (RBV) of the firm and strategic HRM theory are considered to gain a deeper understanding of family firms' adaptive managerial activities.
Temporal dimensions of knowledge exchanges in horizontal knowledge networks
Authors: Abualqumboz Moheeb , Chan Paul W. , Bamford David , Reid Iain
Published: October 2020

Purpose

This study aims to examine reciprocal exchanges in knowledge networks using temporal differentiation of knowledge exchanges. To date, research on horizontal knowledge networks rather overlooks the temporal perspective, which could explain the dynamics of exchange in those networks.

Design/methodology/approach

The paper reports on a study of four horizontal knowledge networks in the UK over a period of 18 months.

Findings

The findings integrate three temporal dimensions of timescale, timeliness and time modalities. The dimensions have implications for the way knowledge is exchanged (or not), which can in turn sustain or stymie productive knowledge exchange in horizontal knowledge networks.

Research limitations/implications

The study encourages researchers to attend to the micro-processes of knowledge exchanges through the integrative framework of temporalities. While this study examined horizontal networks, future research can be extended to analysing temporalities in other types of networks.

Practical implications

It seeks to inspire practitioners to appreciate how the impacts of knowledge networks play out in/over time, and how more effective coopetitive knowledge-sharing environments can be created and sustained by taking differentiated time structures into account.

Originality/value

This study contributes to the knowledge management literature by providing a temporal perspective to understand reciprocal knowledge exchanges in horizontal knowledge networks.
Overcoming risk for women in leader identity development
Authors: Ryan Nuala F. , Hammond Michelle , MacCurtain Sarah , Cross Christine
Published: October 2020

Purpose

The purpose of this paper is to advance our understanding of the role of risk in leader identity development for women by identifying processes women leaders employ to overcome perceived risk.

Design/methodology/approach

Twenty-five women leaders in the Irish healthcare sector took part in an 18-month long identity-based leadership development program. Qualitative data from interviews, focus groups, critical incident diaries and individual exit surveys and observations were analyzed using the constant comparative method.

Findings

Four key processes are identified as women leaders work through risks associated with structural elements (perceiving and mitigating structural risk) and agency of the leader (accepting agentic risks and developing agency).

Research limitations/implications

Like many focused qualitative studies, generalizability to a larger population might be limited. The authors, therefore, recommend future research to consider these issues in other industries, levels and national contexts.

Practical implications

Organizational members should pay attention to structural factors that affect women's perceptions of risks in internalizing a leader identity such as perceptions of organizational support for development, role models, mentoring and behavioral norms. Programs should aim to increase individual agency through personal reflection and freedom to experiment.

Originality/value

This paper offers an original and nuanced perspective on the role of risk in the leader identity development process for women.
Building social capital for constructive adaptive capacity under social stress
Authors: Wang Yutong , Ko Pakon , Law Nancy
Published: October 2020

Purpose

This study examines how a school progressively built its social capital for agile adaptation to provide inclusive and effective fully online learning provisions through intentionally enhancing its architecture for learning.

Design/methodology/approach

The authors conducted a case study to examine how school A was able to respond rapidly and progressively to the demand for quality online learning provisions in the face of unanticipated school closure with an uncertain end date. Video recordings of online school sharing sessions, interviews and documents provided by the school constituted data sources for this study.

Findings

In creating a collective new norm for the implementation of online learning, a school needs to enhance both structural and cognitive aspects of its social capital. School A achieved this through intentional changes to its architecture for learning (i.e. organizational structure, interaction mechanisms, mediating artifacts and technology) when deliberating measures to deliver the changes under periods of serious social stress.

Originality/value

Adaptive capacity is a core demand on the social capital of schools and organizations under the “new normal” when the future is unpredictable. This paper uncovers the connection between a school's architecture for learning and its adaptive capacity.
A real estate portfolio management risk assessment framework for nonlisted real estate funds in India
Authors: Gupta Ashish , Newell Graeme
Published: October 2020

Purpose

This study provides an extensive risk assessment framework for nonlisted real estate funds' (NREFs) portfolio management in India across their life cycle; that is, the investment stage, the monitoring stage and the exit stage in an emerging market context. The study of risk across these three stages is a new addition to the literature and assumes importance in the context of real estate portfolio management for NREFs in the emerging markets (e.g. India), which are predominantly an opportunistic investment play.

Design/methodology/approach

The risk assessment framework is built on the multiactor/multicriteria risk priorities, using analytical hierarchy process (AHP), obtained from 35 experts in four real estate fund management professional groups; namely, investors/fund managers, valuers, consultants and international developers.

Findings

The results demonstrate that the real estate portfolio management risk priorities change across the three life cycle stages of the fund. At the investment stage, specific risks are most critical; at the monitoring stage, it is important to concentrate on all three risks – specific, systematic and management risks; and at the exit stage, systematic risk plays a crucial role. Real estate portfolio management risk evaluation at the subfactor level shows that investee/partner and location selection needs to be critically evaluated at the time of the investment; project execution and quality of development must be monitored during the construction/monitoring period; and repatriation of the funds, currency volatility and exit risk (resale) are critical at the exit stage of the fund.

Practical implications

The understanding of the real estate portfolio management risk transformation across the life cycle stages is crucial for NREF managers for risk minimization, transfer and mitigation strategy formulation in their real estate portfolios. Unlike previous research that evaluates investment risk, this study breaks the NREF's risks into the investment, monitoring and exit stages. The key risk factors for each stage depend on the NREF's real estate activities for that stage. These activities, in turn, give rise to a typical risk profile for that stage. The findings are crucial for the various stakeholders of real estate fund management and policymakers in an emerging market context; particularly India, one of the fastest growing major economies in the world.

Originality/value

This risk assessment framework for simultaneously assessing risk across the three life cycle stages of NREFs is a new addition to the literature.
Comparative effectiveness of Lopinavir/Ritonavir‐based regimens in COVID‐19
Authors: Qu Jian , Li Guo‐Hua , Wang Jiao‐Jiao , He Ge‐Fei , Huang Juan‐Juan , Chen Ying , Qu Qiang , Chen Xiang‐Yu , Lu Qiong
Published: October 2020

The coronavirus disease 2019 (COVID‐19) is an epidemic disease caused by the Severe Acute Respiratory Syndrome Corona Virus 2 (SARS‐CoV‐2) and spreading throughout the world rapidly. Here we evaluated the efficacy of the Lopinavir/Ritonavir (LPV/r) and its combination with other drugs in the treatment of COVID‐19. We included 170 confirmed COVID‐19 patients who had been cured and discharged. Their antiviral therapies were LPV/r alone or combinations with interferon (IFN), Novaferon and Arbidol. We evaluated the medication efficacy by comparing the time of the negative nucleic acid conversion and the length of hospitalization mainly. The LPV/r + Novaferon [6.00 (4.00–8.00) and 7.50 (5.00–10.00) days] had shorter time of the negative nucleic acid conversion (P = .0036) and shorter time of hospitalization (P < .001) compared with LPV/r alone [9.00 (5.00–12.00) and 12.00 (11.00–15.00) days] and LPV/r + IFN [9.00 (7.25–11.00) and 12.00 (10.00–13.50) days]. On the contrary, LPV/r + IFN [9.00 (7.25–11.00) and 12.00 (10.00–13.50) days] had shorter time of the negative nucleic acid conversion (P = .031) and shorter time of hospitalization (P < .001) compared with LPV/r + IFN +Novaferon [10.00 (8.00–11.25) and 13.50 (11.50–17.00) days] and LPV/r + IFN +Arbidol [14.00 (9.75–19.00) and 19.50 (13.25–24.00) days]. In conclusion, the combination of LPV/r and Novaferon may have better efficacy against COVID‐19. However, adding IFN based on LPV/r + Novaferon or adding Arbidol based on LPV/r + IFN may not improve the efficacy.
Ribonucleases control distinct traits of Pseudomonas putida lifestyle
Authors: Apura Patrícia , de Lorenzo Víctor , Arraiano Cecília M. , Martínez‐García Esteban , Viegas Sandra C.
Published: October 2020

The role of archetypal ribonucleases (RNases) in the physiology and stress endurance of the soil bacterium and metabolic engineering platform Pseudomonas putida KT2440 has been inspected. To this end, variants of this strain lacking each of the most important RNases were constructed. Each mutant lacked either one exoribonuclease (PNPase, RNase R) or one endoribonuclease (RNase E, RNase III, RNase G). The global physiological and metabolic costs of the absence of each of these enzymes were then analysed in terms of growth, motility and morphology. The effects of different oxidative chemicals that mimic the stresses endured by this microorganism in its natural habitats were studied as well. The results highlighted that each ribonuclease is specifically related with different traits of the environmental lifestyle that distinctively characterizes this microorganism. Interestingly, the physiological responses of P. putida to the absence of each enzyme diverged significantly from those known previously in Escherichia coli. This exposed not only species‐specific regulatory functions for otherwise known RNase activities but also expanded the panoply of post‐transcriptional adaptation devices that P. putida can make use of for facing hostile environments.
Differential recruitment of opportunistic taxa leads to contrasting abilities in carbon processing by bathypelagic and surface microbial communities
Authors: Sebastián Marta , Forn Irene , Auladell Adrià , Gómez‐Letona Markel , Sala M. Montserrat , Gasol Josep M. , Marrasé Cèlia
Published: October 2020

Different factors affect the way dissolved organic matter (DOM) is processed in the ocean water column, including environmental conditions and the functional capabilities of the communities. Recent studies have shown that bathypelagic prokaryotes are metabolically flexible, but whether this versatility translates into a higher ability to process DOM has been barely explored. Here we performed a multifactorial transplant experiment to compare the growth, activity and changes in DOM quality in surface and bathypelagic waters inoculated with either surface or bathypelagic prokaryotic communities. The effect of nutrient additions to surface waters was also explored. Despite no differences in the cell abundance of surface and deep ocean prokaryotes were observed in any of the treatments, in surface waters with nutrients the heterotrophic production of surface prokaryotes rapidly decreased. Conversely, bathypelagic communities displayed a sustained production throughout the experiment. Incubations with surface prokaryotes always led to a significant accumulation of recalcitrant compounds, which did not occur with bathypelagic prokaryotes, suggesting they have a higher ability to process DOM. These contrasting abilities could be explained by the recruitment of a comparatively larger number of opportunistic taxa within the bathypelagic assemblages, which likely resulted in a broader community capability of substrate utilization.
‘Better in kung fu movies than in political parties’: Labour’s Factionalism and a Reappraisal of Eric Hobsbawm’s Political Thought
Authors: Pike Karl , Diamond Patrick
Published: October 2020

Eric Hobsbawm will forever be a giant intellectual figure. Yet, an aspect of his work is underappreciated—the case for a more pluralistic, dynamic and intellectually inquiring Labour Party. As such, his political thought is particularly relevant given the recent election of Keir Starmer, and the avowed quest for ‘unity’ in bringing Labour back to power. Hobsbawm came to believe that political strategies which sought to exploit social and political stratification and conflict—such as vilifying reformist political movements and those of moderate persuasion—doomed Labour to permanent opposition. A broad‐based people’s party, uniting objectives of solidarity and aspiration, was the only viable class politics. Although from the Marxist tradition, Hobsbawm believed Labour’s purpose was to make liberal democracy function more effectively, rather than creating an alternative economic and political system. Suggesting conflict was more suited to kung fu movies, Hobsbawm’s predominant theme of ‘anti‐factionalism with a purpose’ remains apposite today.
The Female Mortality Advantage in the Seventeenth‐Century Rural Low Countries
Authors: Curtis Daniel R. , Han Qijun
Published: October 2020

Data from famines from the nineteenth century onward suggest that women hold a mortality advantage during times of acute malnutrition, while modern laboratory research suggests that women are more resilient to most pathogens causing epidemic diseases. There is, however, a paucity of sex‐disaggregated mortality data for the period prior to the Industrial Revolution to test this view across a broader span of history. We offer a newly compiled database of adult burial information for 293 rural localities and small towns in the seventeenth‐century Low Countries, explicitly comparing mortality crises against ‘normal’ years. In contrast to expected results, we find no clear female mortality advantage during mortality spikes and, more to the point, women tended to die more frequently than men when only taking into account those years with very severe raised mortality. Gender‐related differences in levels of protection, but also exposure to vectors and points of contagion, meant that some of these female advantages were ‘lost’ during food crises or epidemic disease outbreaks. Responses to mortality crises such as epidemics may shine new light on gender‐based inequalities perhaps hidden from view in ‘normal times’ – with relevance for recent work asserting ‘female agency’ in the early modern Low Countries context.
Cognitive subgroups in first episode bipolar I disorder: Relation to clinical and brain volumetric variables
Authors: Chakrabarty Trisha , Torres Ivan J. , Su Weizhong W. , Sawatzky Richard , Keramatian Kamyar , Yatham Lakshmi N.
Published: October 2020

Objective

Distinct cognitive subgroups are seen in patients with long duration bipolar I disorder (BDI), possibly reflective of underlying pathophysiological differences. It is unknown whether such cognitive heterogeneity is present at illness onset. We applied latent class analysis (LCA) to cognitive test scores in first episode BDI patients. Exploratory analysis elucidated whether impaired subgroups were characterized by ‘early neurodevelopmental’ (low premorbid IQ and intracranial volume) versus ‘later neurodevelopmental’ (decline from premorbid to current IQ, changes in relative grey (GM)/white (WM) matter volumes) pathology.

Methods

Recently recovered first manic episode BDI patients (n = 91) and healthy controls (HC, n = 63) comprised the study sample. LCA identified subgroups based on processing speed, verbal memory, non‐verbal memory, executive functioning, attention and working memory scores. Subgroups were compared amongst each other and HC on premorbid/current IQ, intracranial (ICV), total brain and regional volumes.

Results

Three cognitive subgroups emerged: (i) globally impaired (GI, n = 31), scoring 0.5‐1 SD below demographically corrected norms across domains, (ii) selectively impaired (SI, n = 47), with predominant processing speed deficits and (iii) high performing (HP, n = 13), with above‐average cognitive performance. GI patients showed a ‘later neurodevelopmental’ pattern, with normal ICV, significant decline from premorbid to current IQ, higher total GM and lower total WM (with respect to total brain volume) versus SI and HC (p = 0.003). GI patients had higher left frontal pole GM versus HC (p < 0.05, FWE corrected).

Conclusions

A globally impaired patient subgroup is identifiable in first episode BDI, possibly characterized by unique neurodevelopmental pathologic processes proximal to illness onset.