bluuebunny/crossref_metadata_2025_split huggingface dataset:
Shared internal models for feedforward and feedback control of arm dynamics in non-human primates
Authors: Maeda Rodrigo S. , Kersten Rhonda , Pruszynski J. Andrew 
Published: April 2020

AbstractPrevious work has shown that humans account for and learn novel properties or the arm’s dynamics, and that such learning causes changes in both the predictive (i.e., feedforward) control of reaching and reflex (i.e., feedback) responses to mechanical perturbations. Here we show that similar observations hold in old-world monkeys (macaca fascicularis). Two monkeys were trained to use an exoskeleton to perform a single-joint elbow reaching and to respond to mechanical perturbations that created pure elbow motion. Both of these tasks engaged robust shoulder muscle activity as required to account for the torques that typically arise at the shoulder when the forearm rotates around the elbow joint (i.e., intersegmental dynamics). We altered these intersegmental arm dynamics by having the monkeys generate the same elbow movements with the shoulder joint either free to rotate, as normal, or fixed by the robotic manipulandum, which eliminates the shoulder torques caused by forearm rotation. After fixing the shoulder joint, we found a systematic reduction in shoulder muscle activity. In addition, after releasing the shoulder joint again, we found evidence of kinematic aftereffects (i.e., reach errors) in the direction predicted if failing to compensate for normal arm dynamics. We also tested whether such learning transfers to feedback responses evoked by mechanical perturbations and found a reduction in shoulder feedback responses, as appropriate for these altered arm intersegmental dynamics. Demonstrating this learning and transfer in non-human primates will allow the investigation of the neural mechanisms involved in feedforward and feedback control of the arm’s dynamics.
A Computational Model of Levodopa-Induced Toxicity in Substantia Nigra Pars Compacta in Parkinson’s Disease
Authors: Muddapu Vignayanandam Ravindernath , Vijayakumar Karthik , Ramakrishnan Keerthiga , Chakravarthy V Srinivasa 
Published: April 2020

ABSTRACTBackgroundParkinson’s disease (PD) is caused by the progressive loss of dopaminergic cells in substantia nigra pars compacta (SNc). The root cause of this cell loss in PD is still not decisively elucidated. A recent line of thinking traces the cause of PD neurodegeneration to metabolic deficiency. Due to exceptionally high energy demand, SNc neurons exhibit a higher basal metabolic rate and higher oxygen consumption rate, which results in oxidative stress. Recently, we have suggested that the excitotoxic loss of SNc cells might be due to energy deficiency occurring at different levels of neural hierarchy. Levodopa (LDOPA), a precursor of dopamine, which is used as a symptom-relieving treatment for PD, leads to outcomes that are both positive and negative. Several researchers suggested that LDOPA might be harmful to SNc cells due to oxidative stress. The role of LDOPA in the course of PD pathogenesis is still debatable.New MethodWe hypothesize that energy deficiency can lead to LDOPA-induced toxicity (LIT) in two ways: by promoting dopamine-induced oxidative stress and by exacerbating excitotoxicity in SNc. We present a multiscale computational model of SNc-striatum system, which will help us in understanding the mechanism behind neurodegeneration postulated above and provides insights for developing disease-modifying therapeutics.ResultsIt was observed that SNc terminals are more vulnerable to energy deficiency than SNc somas. During LDOPA therapy, it was observed that higher LDOPA dosage results in increased loss of somas and terminals in SNc. It was also observed that co-administration of LDOPA and glutathione (antioxidant) evades LDOPA-induced toxicity in SNc neurons.Comparison with Existing MethodsOur proposed multiscale model of SNc-striatum system is first of its kind, where SNc neuron was modelled at biophysical level, and striatal neurons were modelled at spiking level.ConclusionsWe show that our proposed model was able to capture LDOPA-induced toxicity in SNc, caused by energy deficiency.
A molecular approach to studying Hymenoptera diets using polistine wasps
Authors: Lefort M.-C. , Beggs J.R. , Glare T.R. , Doyle E.J. , Saunders T.E. , Boyer S. 
Published: April 2020

AbstractThe study of animal diets has benefited from the rise of high-throughput DNA sequencing applied to stomach content or faecal samples. The latter can be fresh samples used to describe recent meals, or older samples, which can inform about past feeding activities. For most invertebrates, however, it is difficult to access ‘historical’ samples, due to the small size of the animals and the absence of permanent defecation sites. Therefore, sampling must be repeated to account for seasonal variation and to capture the overall diet of a species.This study develops a method to describe the overall diet of nest-building Hymenoptera based on a single sampling event, by analysing prey DNA from faeces accumulated in brood cells. We collected 48 nests from two species of introduced paper wasps (Polistes chinensis, andP. humilis) in the urban and peri-urban areas of Auckland, New Zealand, and selected two samples per nest. One from brood cells in the outer layer of the nest to represent the most recent diet, and one from brood cells in an inner layer to represent older diet.Diet differed between species, although both fed mainly on Thysanoptera, Lepidoptera and Acariformes. Prey taxa identified to species level included both agricultural pests and native species. Prey communities consumed were significantly different between inner and outer nest samples suggesting seasonal variation in prey availability and/or a diversification of the wasps’ diet as the colony grows. We also show for the first time potential predation of marine organisms by Polistes wasps.Our study provides field evidence that polistine wasps feed on agricultural pests, supporting the hypothesis that some social wasp species could have a suppressing effect on agricultural pests. The proposed methodology is readily applicable to other nest-building Hymenoptera and has the potential to provide comprehensive knowledge about their diet with minimum sampling effort. Such knowledge is Essential to measure the ecological impact of invasive Vespidae and support the conservation of native invertebrate biodiversity.
Inhibitor of Differentiation 4 (ID4) represses myoepithelial differentiation of mammary stem cells through its interaction with HEB
Authors: Holliday Holly , Roden Daniel , Junankar Simon , Wu Sunny Z. , Baker Laura A. , Krisp Christoph , Chan Chia-Ling , McFarland Andrea , Skhinas Joanna N. , Cox Thomas R. , Pal Bhupinder , Huntington Nicholas , Ormandy Christopher J. , Carroll Jason S. , Visvader Jane , Molloy Mark P. , Swarbrick Alexander 
Published: April 2020

AbstractDifferentiation of stem cells embedded within the mammary epithelium is orchestrated by lineage-specifying transcription factors. Unlike the well-defined luminal hierarchy, dissection of the basal lineage has been hindered by a lack of specific markers. Inhibitor of Differentiation 4 (ID4) is a basally-restricted helix-loop-helix (HLH) transcription factor essential for mammary development. Here we show that ID4 is highly expressed in basal stem cells and decreases during myoepithelial differentiation. By integrating transcriptomic, proteomic, and ChIP-sequencing data, we reveal that ID4 is required to suppress myoepithelial gene expression and cell fate. We identify the bHLH protein HEB as a direct binding partner of ID4, and describe a previously-unknown role for this regulator in mammary development. HEB binds to E-boxes in regulatory elements of developmental genes, negatively regulated by ID4, involved in extracellular matrix synthesis and cytoskeletal contraction. Together our findings support a model whereby ID4 binds to HEB and blocks it from promoting myoepithelial specialisation. These new insights expand our current understanding into control of myoepithelial differentiation and mammary gland morphogenesis.
Acute aggressive behavior perturbates the oxidative status of a wild bird independently of testosterone and progesterone
Authors: Mentesana Lucia , Adreani Nicolas M. 
Published: April 2020

AbstractAerobically demanding activities like aggression can lead to an elevated oxidative metabolism affecting the concentration of pro-oxidant and antioxidant compounds and can result in an overall perturbation of the oxidative status. Aggression may also alter the oxidative status indirectly through an increase in testosterone and progesterone concentrations. Given that changes in the oxidative status could represent a physiological cost of aggression, we tested the hypothesis that acute conspecific aggression impairs the oxidative status and evaluated the role of testosterone and progesterone as potential mediators. To achieve this, we experimentally manipulated the aggressive behavior of wild female and male birds and measured the concentrations of pro-oxidants, enzymatic- and non-enzymatic antioxidants, testosterone and progesterone in blood. After 20 minutes of conspecific aggressive behavior, both sexes had lower concentrations of non-enzymatic antioxidants than control individuals. This effect was independent of testosterone and progesterone concentrations, and much stronger in females than in males. Further, only in females (but not in males) being more aggressive came at the expense of lower antioxidant concentration. We provide the first experimental evidence that acute aggressive behavior perturbates the oxidative state of a wild vertebrate independently of testosterone and progesterone, with potential ecological and evolutionary implications given the role of the redox system in shaping life-history traits.
Hybrid genome assembly and evidence-based annotation of the egg parasitoid and biological control agentTrichogramma brassicae
Authors: Ferguson K. B. , Kursch-Metz T. , Verhulst E. C. , Pannebakker B. A. 
Published: April 2020

ABSTRACTTrichogramma brassicae(Bezdenko) are egg parasitoids that are used throughout the world as biological control agents and in laboratories as model species. Despite this ubiquity, few genetic resources exist beyond COI, ITS2, and RAPD markers. Aided by aWolbachiainfection, a wild-caught strain from Germany was reared for low heterozygosity and sequenced in a hybridde novostrategy, after which several assembling strategies were evaluated. The best assembly, derived from a DBG2OLC-based pipeline, yielded a genome of 235 Mbp made up of 1,572 contigs with an N50 of 556,663 bp. Following a rigorousab initio-, homology-, and evidence-based annotation, 16,905 genes were annotated and functionally described. As an example of the utility of the genome, a simple ortholog cluster analysis was performed with sister speciesT. pretiosum, revealing over 6000 shared clusters and under 400 clusters unique to each species. The genome and transcriptome presented here provides an essential resource for comparative genomics of the commercially relevant genusTrichogramma, but also for research into molecular evolution, ecology, and breeding ofT. brassicae.
Redistribution of cholesterol from vesicle to plasmalemma controls fusion pore geometry
Authors: Rituper Boštjan , Guček Alenka , Lisjak Marjeta , Gorska Urszula , Šakanović Aleksandra , Bobnar Saša Trkov , Lasič Eva , Božić Mićo , Abbineni Prabhodh S. , Jorgačevski Jernej , Kreft Marko , Verkhratsky Alexei , Platt Frances M. , Anderluh Gregor , Stenovec Matjaž , Božič Bojan , Coorssen Jens R. , Zorec Robert 
Published: April 2020

ABSTRACTEukaryotic vesicles fuse with the plasmalemma to form the fusion pore, previously considered to be unstable with widening of the pore diameter. Recent studies established that the pore diameter is stable, reflecting balanced forces of widening and closure. Proteins are considered key regulators of the fusion pore, whereas the role of membrane lipids remains unclear. Super-resolution microscopy revealed that lactotroph secretory vesicles discharge cholesterol after stimulation of exocytosis; subsequently, vesicle cholesterol redistributes to the outer leaflet of the plasmalemma. Cholesterol depletion in lactotrophs and astrocytes evokes release of vesicle hormone, indicating that cholesterol constricts the fusion pore. A new model of cholesterol-dependent fusion pore diameter regulation is proposed. High-resolution measurements of fusion pore conductance confirmed that the fusion pore widens with cholesterol depletion and constricts with cholesterol enrichment. In fibroblasts lacking the Npc1 protein, in which cholesterol accumulates in vesicles, the fusion pore is narrower than in controls, showing that cholesterol regulates fusion pore geometry.Graphical AbstractTop: stages through which a vesicle interacts with the plasmalemma. Stage A denotes hemifusion, which proceeds to stage B, with a narrow fusion pore, which can then reversibly open (stage C), before widening fully (stage D). Bottom: redistribution of cholesterol from the vesicle to the outer leaflet of the plasmalemma controls fusion pore constriction.In BriefA membrane pore is formed when the vesicle membrane fuses with the plasmalemma. Proteins were considered key regulators of the opening and closing of this fusion pore. Here, evidence is provided to show that cholesterol, a membrane constituent, determines a radial force constricting the fusion pore, revealing that the fusion pore functions as a proteolipidic structure.HighlightsIntravesicular cholesterol redistributes to the outer leaflet of the plasmalemma.Cholesterol depletion widens the fusion pore, whereas cholesterol enrichment constricts the fusion pore.A model of cholesterol-dependent force preventing fusion pore widening is developed.Disease-related increase in vesicle cholesterol constricts the fusion pore.
A patent-based model of entrepreneurship education in Brazil
Authors: Cavalheiro Gabriel Marcuzzo do Canto , Cavalheiro Mariana Brandao , Mariano Sandra 
Published: April 2020

PurposeThis article is aimed at improving understanding of the possibilities and implications of using patents as a teaching instrument for universities in developing countries in order to enable undergraduate business students to discuss critical issues associated with the commercialization of technological innovations.Design/methodology/approachThis study is based on an explorative case of an experiential teaching exercise involving undergraduate students addressing the development of business plans addressing the commercialization of patents. In this way, we proposed the POSTE model to provide a pathway to knowledge creation by integrating entrepreneurial competences of entrepreneurship competences with existing practices.FindingsGiven the complex nature of the patenting process, the experiential exercise proposed by this study contributes to enhance IP commercialization capabilities of undergraduate students by simulating decision-making regarding market size, user requirements, product pricing, competitors, substitute products, time-to-market, product production arrangements and strategic use of the terms of a patent.Research limitations/implicationsOne limitation of this research involves the impossibility of completely addressing the venture launch gap. Despite the realistic learning experience based on a real patent, as students do not own the intellectual property rights (IPRs) associated with the patents used in the course, it is not possible to implement the business models developed during the course.Practical implicationsSince patent documents are freely available and companies are increasingly dependent on intellectual property (IP) assets to remain competitive, our study provides evidence that patents can provide a rich source of information that can be used to simulate venture creations by taking into consideration economical, strategical, and legal skills needed to bridge the technology commercialization gap.Social implicationsGiven the lack of courses addressing intellectual property in the wide majority of Brazilian undergraduate courses, the teaching experience described in this study contributes to raise the sense of urgency for the commercialization of patents among college students, as a means of turning technology into business.Originality/valueDespite of the growing correlation between IP and competitiveness, teaching methods relying on IP data, such as patents, industrial designs and trademarks, in research institutions located in developing countries have received limited treatment in the extant literature.
A short measure of innovative work behaviour as a dynamic, context-bound construct
Authors: Messmann Gerhard , Mulder Regina H. 
Published: April 2020

PurposeThis contribution aims at providing a measure of the overall construct of innovative work behaviour (IWB). As a consequence of the construct's dynamic, context-bound nature, the measure of IWB is based on concrete work activities, captures social and reflective activities, and is context-bound. By employing a short, one-dimensional measurement scale, the instrument enables valuable scientific and practical insights in an economical way.Design/methodology/approachThe measure of IWB was evaluated with two samples of employees in different work contexts by conducting psychometric analyses, reliability analyses, exploratory and confirmatory factor analyses and correlation analyses with criterion variables.FindingsThe study provides evidence for the psychometric quality, reliability and validity of the measure of IWB.Research limitations/implicationsThe measure can be used to efficiently measure overall IWB. It thus enables the investigation of complex research models involving intervening mechanisms, interactions, or longitudinal effects. Further validation in other work domains and the inclusion of other criterion variables, such as innovative outcomes, is advised.Practical implicationsThe measure is useful for organizational practitioners to efficiently assess employees' IWB, to determine needs for supporting IWB at organizational level, and as a conceptual guideline for designing training or giving performance feedback during innovation projects.Originality/valueThe measure enables insights into the question how IWB can be fostered in practice. In addition, the contribution highlights that a measure of IWB needs to account for the construct's dynamic, context-bound nature and pay attention to usability as an important but often neglected quality criterion.
Intra‐ASEAN student mobility: overview, challenges and opportunities
Authors: Chao Roger Yap 
Published: April 2020

PurposeThis paper explores the issue of developing and enhancing intra-ASEAN international student mobility given the context of ASEAN integration, regionalization of ASEAN higher education and the various intra‐ASEAN student mobility schemes currently implemented.Design/methodology/approachIt explores higher education policies, available higher education and international student mobility data, as well as the various intra‐ASEAN (and relevant) student mobility schemes to present the current status of intra‐ASEAN student mobility, challenges and opportunities to further enhance student mobility within the ASEAN region.FindingsAside from showing that intra‐ASEAN student mobility is significantly low compared to outbound student mobility from ASEAN countries, the paper also highlights the relationship between a country’s income status with choice of intra‐ASEAN or extraASEAN student mobility. Finally, it recommends developing a comprehensive intra‐ASEAN mobility scheme taking the merits of the various intra‐ASEAN mobility schemes currently implemented and guided by developments in the European ERASMUS mobility programs.Originality/valueThis is probably the first (in fact, it is an exploratory) paper that address the issue of intra‐ASEAN international student mobility, which aims to explore relevant issues to address the development of a comprehensive ASEAN mobility scheme.
Understanding physician leadership: the mediating effects of positive organizational climate and relational role endorsement
Authors: Quinn Joann Farrell , Cola Philip 
Published: April 2020

PurposeThe purpose of this paper is to seek clarity on the factors that increase acceptance of a leadership identity and influence a physician leader to participate in the leader role at a higher level.Design/methodology/approachTo explore the direct and mediating effects of positive psychological climate (PPC) and role endorsement (RE) on physician professional participation (PP) in leadership, a survey was disseminated to members of the American Association of Physician Leadership.FindingsFindings show that positive relationships support the individual in acceptance of a second identity as a leader, therefore, to a higher level of PP. The double mediation with PPC and RE found in this model warrants additional meaning toward the cultivation of positive relationships.Research limitations/implicationsA broader understanding of physician leadership may benefit from a more comprehensive collection procedure other than self-reported data, including one in which data is collected in a 360-degree feedback format.Practical implicationsRole endorsement serves as a mediating mechanism to PP (citizenship behaviors) for both PPC and social intelligence competencies. These data indicate that the presence of role endorsement for physicians changes their degree of participation and impacts their own role identity. This immediately helps to direct development efforts for physicians during their transition from physician to physician leader.Originality/valueThis study confirms the mediating relationship of REupon the PP of physician leaders, with both implications for practice and a broader understanding of the nature of physician leadership.
An investigation of characteristics of effective global leaders
Authors: Geil Marc A. , Greenwald Jessica 
Published: April 2020

PurposeThe purpose of this study is to unite research in cultural intelligence (CQ), core confidence and multitasking to examine how these characteristics interplay in the perceptions of global leadership effectiveness.Design/methodology/approachThe sample comprised 149 employees, mostly managers from 21 countries with 18 native languages spoken who had global leadership experience while working fulltime for international organizations. Relationships were examined using the hierarchical linear regression of survey data.FindingsSupport is found for core confidence moderating the relationship between CQ and other-rated and self-rated perceptions of global leadership effectiveness such that the relationship is stronger when leader core confidence is high. Moreover, support is found for CQ and core confidence having positive relationships with self-rated perceptions of global leadership effectiveness, and the study found a positive relationship between CQ and multitasking.Practical implicationsThe relationships studied provide practitioners with information to supplement the employee selection process for global leaders. The ability to assess current or future employees and hedge organizational risk in assignment to global leadership positions could have a significant impact.Originality/valueThis study contributes to the literature by investigating individual characteristics contributing to the perceptions of global leadership effectiveness. Because perceptions are often acted on as if reality and globalization in our personal and work lives is expansive, understanding these relationships is important.