bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mass spectrometric based detection of protein nucleotidylation in the RNA polymerase of SARS-CoV-2
Authors: Conti Brian J. , Kirchdoerfer Robert N. , Sussman Michael R. 
Published: October 2020

SummaryCoronaviruses, like SARS-CoV-2, encode a nucleotidyl transferase in the N-terminal NiRAN domain of thenon-structuralprotein (nsp) 12 protein within theRNA dependentRNApolymerase (RdRP)1-3. Though the substrate targets of the viral nucleotidyl transferase are unknown, NiRAN active sites are highly conserved and essential for viral replication3. We show, for the first time, the detection and sequence location of GMP-modified amino acids in nidovirus RdRP-associated proteins using heavy isotope-assisted MS and MS/MS peptide sequencing. We identified lys-143 in the equine arteritis virus (EAV) protein, nsp7, as a primary site of nucleotidylation in vitro that uses a phosphoramide bond to covalently attach with GMP. In SARS-CoV-2 replicase proteins, we demonstrate a unique O-linked GMP attachment on nsp7 ser-1, whose formation required the presence of nsp12. It is clear that additional nucleotidylation sites remain undiscovered, which includes the possibility that nsp12 itself may form a transient GMP adduct in the NiRAN active site that has eluted detection in these initial studies due to instability of the covalent attachment. Our results demonstrate new strategies for detecting GMP-peptide linkages that can be adapted for higher throughput screening using mass spectrometric technologies. These data are expected to be important for a rapid and timely characterization of a new enzymatic activity in SARS-CoV-2 that may be an attractive drug target aimed at limiting viral replication in infected patients.
Attitude vs involvement: a systematic literature review at the intersection between engagement and innovation
Authors: Trabucchi Daniel , Bellis Paola , Di Marco Diletta , Buganza Tommaso , Verganti Roberto 
Published: October 2020

PurposeIn a world where innovation became a “buzzword” and everyone within companies is required to foster innovation, the engagement of people toward innovation is fundamental to prompt individual motivation and actions to make innovation happen. However, despite the relevance of the relationship between engagement and innovation, the literature on the topic appears still fragmented. The purpose of this study is to provide an overview of the topic through a systematic literature review.Design/methodology/approachA final sample of 108 papers has been selected and analyzed through co-citation and text mining analyses. The former enabled the analysis of the structure of the theoretical foundation of the filed, while the latter facilitated a systematic and unbiased content-driven review of the literature.FindingsThe results of the analysis indicated two main areas of interest describing the relationship between engagement and innovation. On the one hand, there is the focus on “engagement as an attitude,” intended as the capacity of individuals to generate and realize innovation. On the other hand, there is a stream of literature focused on “engagement as involvement,” which refers to co-innovation paradigms, involving both internal and external stakeholders.Research limitations/implicationsFrom an academic perspective, this paper highlights the relevance of the “human-side” of innovation, proposing avenues for future research that dig into the relationship between people's engagement and innovation dynamics. Moreover, it shows how the recent developments in the innovation management literature are coherent with this emerging relevance of the human perspective in innovation.Practical implicationsFrom a practitioner’s perspective, this paper helps managers by highlighting the two different approaches that they can have in terms of engagement. The study aims to help them in identifying the kind of engagement they are looking for in their employees and other innovation stakeholder having the support to find relevant studies in that direction.Originality/valueThe study unveils how the evolution of both areas over the years is strictly related to the megatrends of innovation fields, which are the main areas of knowledge not covered yet. Therefore, a research agenda is proposed.
Political uncertainty and the choice of external audit: international evidence from private firms
Authors: Farooq Omar , Satt Harit , El Fadel Basma 
Published: October 2020

PurposeThis paper documents the impact of political uncertainty on the decision of private firms to use external auditors to verify their financial statements.Design/methodology/approachThe authors use the data from 141 countries and the pooled logistic regression to test our arguments. The data is provided by the World Bank's Enterprise Surveys and is collected during the period between 2006 and 2019.FindingsThe results show that firms with high exposure to political uncertainty are more likely to use external auditors to verify their financial statements. The results are robust across various sub-samples and hold when we use alternate proxy for political uncertainty. The results are also robust after controlling for potential endogeneity concerns. The authors also find that the effect of political uncertainty on the choice of external audit is more pronounced for firms that are headquartered in countries with weak institutional environment. The authors document significant role of democracy, rule of law and accountability in determining the relationship between political uncertainty and the choice of external audit.Originality/valueThe authors believe that theirs is one of the initial attempts (if not the first) to investigate the effect of political uncertainty on the choice of external audit among the private firms in developing countries.
Failure analysis and countermeasures of the SCM435 high-tension bolt of three-step injection mold
Authors: Nam Ki-Woo , Yun Seo-Hyun 
Published: October 2020

PurposeThe objective of this study was to perform damage analysis of SCM435 high-tension bolts connecting upper and lower parts of a three-stage injection molding machine.Design/methodology/approachDamage material used in this study was a SCM435 high-strength bolt connecting upper and lower molds of a three-stage injection mold. Causes of damage were determined by macroscopic observation. Microstructure observation was done using a metallic microscope, scanning electron microscope (SEM, S-2400, HiTachi, Japan), energy dispersive X-ray spectroscopy (EDS, Kevex Ltd., Sigma) and Vickers hardness tester (HV-114, Mitutoyo). Fatigue limit of the damaged material was evaluated using equivalent crack length.FindingsBolts were fractured by cyclic bending stress in the observation of ratchet marks and beach marks. The damaged specimen showed an acicular microstructure. Impurity was observed. Chromium carbide was observed near the crack origin. Both shape parameters of the Vickers hardness were similar. However, the scale parameter of the damaged specimen was about smaller than that of the as-received specimen. Much degradation occurred in the damaged specimen. Bolts should undergo accurate heat treatment to prevent the formation of chromium carbide. They must prevent the action of dynamic stresses. Bolts need accurate tightening and accuracy of heat treatment. Screws require compression residual stress due to peening.Originality/valueThis study conducted failure analysis of damaged SCM435 bolts connecting upper and lower parts of the three-stage injection mold. Fatigue limit of the damaged material was evaluated using equivalent crack length. In order to control this fracture, accurate tightening of bolts, accuracy of heat treatment and screws are required for compression residual stress due to peening.
Determinants of Vietnam's rice and coffee exports: using stochastic frontier gravity model
Authors: Nguyen Dao Dinh 
Published: October 2020

PurposeThe paper aims to estimate the factors affecting Vietnam's export in rice and coffee, the two most important agricultural products, especially in exploring the role of “behind-the-border” constraints.Design/methodology/approachThe paper applies the stochastic frontier gravity model, which models the aggregate effect of “behind-the-border” factors for Vietnam's export in rice and coffee.FindingsThe paper finds that the impact of “behind-the-border” constraints is statistically significant, suggesting that Vietnam's exports in rice and coffee may be prevented from reaching their export potential by such factors. Moreover, technical efficiency and potential export suggest that Vietnam has a lot of potential to increase its exports in rice and coffee with its major trading partners. The Association of Southeast Asian Nations group continues to be the major market of Vietnamese rice and coffee. Vietnam can also take advantage of the opportunity to export these commodities to the European Union (EU) (not including the UK), and Comprehensive and Progressive Agreement for Trans-Pacific Partnership, especially in coffee to the EU.Research limitations/implicationsThe study cannot identify specific “behind-the-border” factors due to the limitation of data availability.Originality/valueMany existing studies suggest that export in agricultural products of Vietnam, especially in rice, is significantly affected by natural factors and “explicit beyond-the-border” constraints. They ignore the impact of “behind-the-border” constraints in Vietnam and its trading partners. My study proved the significant impact of such constraints. Therefore, Vietnam needs more policies to remove the “behind-the-border” constraints to promote export in rice and coffee.
The sequence of implementation of reconfigurability core characteristics in manufacturing systems
Authors: Maganha Isabela , Silva Cristovao , Ferreira Luis Miguel D.F. 
Published: October 2020

PurposeThe objective of this study is to propose a sequence of implementation of the core characteristics of reconfigurability: modularity, integrability, diagnosability, adaptability and customization. For this purpose, the relationships among the core characteristics and Industry 4.0 technologies are analyzed as well as the impacts of one core characteristic on another.Design/methodology/approachThis study presented tests and validated two hypothesized models based on the literature. This paper was based on a questionnaire survey. Portuguese manufacturing companies were the sampling frame. In total, 600 questionnaires were distributed and a total of 112 responses were eligible for statistical processing, representing a response rate of 18.7%. Structural equation modeling (SEM) was used to hypothesize the sequence of implementation of the core characteristics of reconfigurability.FindingsThe findings presented a roadmap to implement reconfigurability, which implies significant managerial contributions on how to make the transition from conventional to reconfigurable manufacturing systems (RMSs). This highlights the importance of the sequence of implementation of the core characteristics in order to make the most of each to achieve reconfigurability.Originality/valueImplementing reconfigurability is crucial to manufacturing companies to respond to changes in production requirements and market fluctuations quickly. However, there is a gap between theory and practice in regard to achieve reconfigurability in existing manufacturing systems. This gap includes (1) understanding the type of relationships among the core characteristics of reconfigurability, (2) understanding the influence that one core characteristic has on another and (3) establishing a sequence of implementation for the core characteristics. This study makes a contribution to fill this gap in the research area.
The “additional costs” of being peripheral: developing a contextual understanding of micro-business growth constraints
Authors: Gherhes Cristian , Vorley Tim , Brooks Chay 
Published: October 2020

PurposeDespite their economic significance, empirical evidence on the growth constraints facing micro-businesses as an important subset of small and medium enterprises remains scarce. At the same time, little consideration has hitherto been given to the context in which entrepreneurial activity occurs. The purpose of this paper is to develop an empirically informed contextual understanding of micro-business growth, beyond firm-level constraints.Design/methodology/approachThe paper draws on 50 in-depth interviews with stakeholders and micro-business owner–manager entrepreneurs (OMEs henceforth) in a peripheral post-industrial place (PPIP henceforth).FindingsThe paper shows that, beyond firm-level constraints generated by their OME-centric nature, there are “additional costs” for micro-businesses operating in PPIPs, specifically limited access to higher-skilled labour, a more challenging, “closed” business environment and negative outward perceptions stemming from place stigmatisation. All of these “additional costs” can serve to stymie OMEs' growth ambition.Research limitations/implicationsThe paper is based on a limited number of interviews conducted in one region in England. However, the contextualisation of the findings through a focus on PPIPs provides valuable insights and enables analytical generalisation.Originality/valueThe article develops a context-sensitive model of micro-business growth constraints, one that goes beyond the constraints inherent in the nature of micro-businesses and is sensitive to their local (socio-institutional) operating context. The implications serve to advance both how enterprise in the periphery is theorised and how it is addressed by policymakers and business intermediaries to support the growth of micro-businesses.
Herding and BRICS markets: a study of distribution tails
Authors: Shrotryia Vijay Kumar , Kalra Himanshi 
Published: October 2020

PurposeThe present study looks into the mimicking behaviour in both normal and asymmetric scenarios. It, then, considers the contagion between the USA and the BRICS stock markets. Finally, it examines herd behaviour in the wake of a major banking policy change concerning the bloc under study.Design/methodology/approachThe current empirical analysis employs daily, weekly and monthly data points to estimate relevant herding parameters. Quantile regression specifications of Changet al.(2000)'s dispersion method have been applied to detect herd activity. Also, dummy regression specifications have been used to examine the impact of various crises and strategically crucial events on the propensity to herd in the BRICS markets. The time period under consideration ranges from January 2011 until May 2019.FindingsThe relevant herding coefficients turn insignificant in most cases for normal and asymmetric scenarios except for China and South Africa. This can be traced to the anti-herding behaviour of investors, where individuals tend to diverge from the consensus. However, turbulence makes all stock markets to show some collective trading except Russia. Further, the Chinese stock market seems immune to the frictions in the US stock market. Finally, the Indian and South African markets witness significant herding during the formation of a common depository institution.Practical implicationsMost stock markets seem to herd during turbulence. This revelation is of strategic importance to the regulators and capital market managers. They have to be cautious during crises periods as the illusion of being secured with the masses ends up creating unprecedented frictions in the financial markets.Originality/valueThe present study seems to be the very first attempt to test the relevant distributions' tails for convergent behaviour in the BRICS markets.
Beware of side effects on quality! Investigating the implications of home working on work-life balance in educational services
Authors: Palumbo Rocco , Manna Rosalba , Cavallone Mauro 
Published: October 2020

PurposeTelecommuting from home is back up on the agenda as a result of the unforeseen challenges brought by COVID-19. Working from home permits to avoid disruption in the ordinary functioning of educational institutions triggered by social distancing. However, home-based telecommuting may have some side effects on employees, especially in terms of work-life balance. Soft Total Quality Management (TQM) initiatives are needed to address these side effects. The article intends to shed light on these issues, providing some food for thought to scholars and practitioners.Design/methodology/approachSecondary data about the working conditions of 2,046 people employed in the education sector across Europe were investigated. A serial mediation analysis was designed to examine the direct and indirect implications of working from home on work-life balance.FindingsThe study suggests that home-based telecommuting may trigger work-to-life and life-to-work conflicts, due to the blurring of boundaries between work and everyday life. Soft tools, such as organizational meaningfulness (OM) and work-related well-being (WB), mediate the relationship between working from home (HW) and work-life conflicts (WLC), lessening the negative implications of working from home on work-life balance.Practical implicationsThe design and the implementation of home-based telecommuting arrangements should include a special concern for soft TQM practices. Among others, OM and WB are likely to minimize the disruption of remote employees' jobs and interpersonal relationships. Failure to do so impairs the ability of home-based employees to make sense out of their working arrangements and to achieve a sustainable work-life balance.Originality/valueThis is one of the first attempts to illuminate the side effects of home-based telecommuting and to investigate the role of soft TQM in addressing these side effects.
Anisotropic attenuation of stratified viscoelastic media
Authors: Zeng Jing , Stovas Alexey , Huang Handong 
Published: October 2020

ABSTRACTAn important cause of seismic anisotropic attenuation is the interbedding of thin viscoelastic layers. However, much less attention has been devoted to layer‐induced anisotropic attenuation. Here, we derive a group of unified weighted average forms for effective attenuation from a binary isotropic, transversely isotropic‐ and orthorhombic‐layered medium in the zero‐frequency limit by using the Backus averaging/upscaling method and analyse the influence of interval parameters on effective attenuation. Besides the corresponding interval attenuation and the real part of stiffness, the contrast in the real part of the complex stiffness is also a key factor influencing effective attenuation. A simple linear approximation can be obtained to calculate effective attenuation if the contrast in the real part of stiffness is very small. In a viscoelastic medium, attenuation anisotropy and velocity anisotropy may have different orientations of symmetry planes, and the symmetry class of the former is not lower than that of the latter. We define a group of more general attenuation‐anisotropy parameters to characterize not only the anisotropic attenuation with different symmetry classes from the anisotropic velocity but also the elastic case. Numerical tests reveal the influence of interval attenuation anisotropy, interval velocity anisotropy and the contrast in the real part of stiffness on effective attenuation anisotropy. Types of effective attenuation anisotropy for interval orthorhombic attenuation and interval transversely isotropic attenuation with a vertical symmetry (vertical transversely isotropic attenuation) are controlled only by the interval attenuation anisotropy. A type of effective attenuation anisotropy for interval TI attenuation with a horizontal symmetry (horizontal transversely isotropic attenuation) is controlled by the interval attenuation anisotropy and the contrast in the real part of stiffness. The type of effective attenuation anisotropy for interval isotropic attenuation is controlled by all three factors. The magnitude of effective attenuation anisotropy is positively correlated with the contrast in the real part of the stiffness. Effective attenuation even in isotropic layers with identical isotropic attenuation is anisotropic if the contrast in the real part of stiffness is non‐zero. In addition, if the contrast in the real part of stiffness is very small, a simple linear approximation also can be performed to calculate effective attenuation‐anisotropy parameters for interval anisotropic attenuation.
Scale‐dependent drivers of the phylogenetic structure and similarity of tree communities in northwestern Amazonia
Authors: González‐Caro Sebastián , Duivenvoorden Joost F. , Balslev Henrik , Cavelier Jaime , Grández César , Macía Manuel J. , Romero‐Saltos Hugo , Sánchez Mauricio , Valencia Renato , Duque Álvaro 
Published: October 2020

Abstract

The extent to which historical dispersal, environmental features and geographical barriers shape the phylogenetic structure and turnover of tree communities in northwestern Amazonia at multiple spatial scales remains poorly understood.

We used 85 floristically standardized 0.1‐ha plots (DBH ≥ 2.5 cm) distributed in three subregions of northwestern (NW) Amazonia across three main habitat types (floodplain, swamp and terra firme forests) to hypothesize that (a) historical dispersal overcome geographical barriers, which meant low local phylogenetic relatedness and low phylogenetic turnover. (b) Geographical barriers triggered dispersal limitation, causing high local and subregional phylogenetic clustering and high regional phylogenetic turnover. (c) Edaphic properties and flooding were negatively associated with stem size and determined the tree phylogenetic structure and turnover at local and regional scales in Amazon forests.

We found that the extent to which environmental or evolutionary features shaped the phylogenetic structure and phylogenetic similarity of tree communities in NW Amazonia was scale dependent. Specifically, we show that the relative importance of environmental factors increases as spatial scale and species pool decreases. Furthermore, we find that these results are generally robust for both adult and juvenile trees.

Synthesis. Our analysis at the regional (NW Amazon) scale lends support to the idea of Amazonian forests as a large meta‐community primarily structured by historical dispersal at large spatial scales with an increasing importance of environmental factors at finer spatial scales. The convergence of ancestral lineages across habitat types may have been due to the relatively recent formation of geographical barriers that promoted local isolation and allopatric speciation.