NUI Maynooth Eprint Archive
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Global Platform, Local Labour: Precarious YouTubing in Ireland and Turkey
No full textThis thesis investigates creative digital labour practices of Irish and Turkish content
creators within the hybrid space of YouTube. It frames YouTube creators who
generate or aspire to earn income via the platform as cultural workers in the platform
economy by acknowledging the similarities in their working conditions with other
platform workers. It also addresses how their media production practices are
negotiated and shaped in particular underrepresented national contexts that take place
in peripheral economies. Rather than macro-level industry-based approaches, the
study employs mixed methods to provide micro-level explanations of platformed
content creation. First, it employs methods from ethnography such as semi-structured
interviews with YouTube creators and observations in their workplaces to trace the
dynamics of production as a culture, to listen to the voices of labourers and to capture
creators’ own realities in their working lives. Second, it benefits from the walkthrough
method to put subjective interpretations of creators into the context of the platform
affordances and regulatory frameworks and considers how these factors shape or
constrain the activity of creators. This study demonstrates that YouTubing has a
precarious nature which shapes creators’ working lives and how they form and
maintain their professional identities inside or outside YouTube careers. The thesis
examines this precarious nature by contextualising creators’ media production and
distribution practices in the platform architecture; more significantly it draws attention
to the complexity of the relationships between platforms, content creator labour and
local contexts, which influences the precariousness of creative digital labour. Thus,
the study contributes to the dominant literature on YouTube which neglects YouTube
creators as shaped by specific economic, political, cultural, and linguistic contexts of
nation-states, instead of assuming them to be a homogeneous group under a global
platform
Identification of integration mechanisms that influence digital platform design choices: a longitudinal study
No full textThe current literature gives a strong outline to conceptualise the characteristics of the design of a digital platform. This includes the design strategy, design features and value creation as the primary considerations. These interconnected domains provide a powerful lens to design choices that a contemporary organisation would need to contemplate. However, there is limited attention to conceptualising the mechanisms to explain how a digital platform's layers integrate. Adopting a critical realist philosophy, research was conducted into how HPE Financial Services (HPEFS) designed and deployed a digital platform to grow the business. The in-depth study was conducted as a seven-year longitudinal study and applied the theoretical generative mechanism model from Henfridsson and Bygstad’s (2013) seminal paper.
The study contributes to the digital platform literature in a number of ways. The results of the study provide a detailed description of three platform integration mechanisms to explain integration at the architectural level between layers – (1) Capability Appropriation, (2) Layer Complementarity and (3) Value Hybridisation. Digital platform integration mechanisms can explain the inherent properties of design choices that, in turn, influence the digital design and the subsequent value creation outcomes. The study has proven that causal structures exist that can act, in context, on design choices an organisation may make on its digital platform (Pawson & Tilley, 1997). These causal mechanisms, when actualised, will explain the observable outcomes or events to demonstrate their alignment to the seminal work of Henfridsson and Bygstad (2013).
From here, they are embedded into a conceptual framework and digital platform design model that outlines the cause-and-effect relationship to explain and theorise what an organisation will experience when designing a digital platform.
These are accompanied by a third contribution, the concept of Corrective Mechanisms. They ensure digital platform stability during changes by keeping the underlying deep structure intact and driving incremental improvement without reconfiguration.
As a final contribution, abstracted from the generative mechanisms, a set of design principles are formulated to guide a firm's efforts in digital transformation. Building on the digital platform design model, they are established based on (1) Linkages, (2) Complements and (3) Synergies between the layers and components of a digital platform
The role of surface modifications in directing protein self-assembly
No full textProteins self-assemble into crystals, gels, amyloid fibrils, amorphous aggregates, dense liquid droplets with implications in several fields such as biotechnology, condensation diseases and the food industry. Self-assembly processes are dictated by protein self-interactions; however, proteins are anisotropic particles, i.e. their surface is chemically heterogeneous. Hence, protein-protein interactions are strongly orientation-dependent and protein self-assembly is dramatically influenced by surface modifications. We examine this topic firstly using a model protein, Human γD-crystallin (HGD), and then on a novel type of Virus-Like Particle (VLP), ADDomer, a promising vaccine candidate.
Human γD-crystallin (HGD) is an eye-lens protein and along with other crystallins, it creates the refractive index gradient necessary for proper lens function. Naturally occurring surface modifications of HGD trigger aggregation/crystallization, leading to age-related or hereditary cataract onset. For these reasons, the influence of surface modifications (such as single-point mutations) on HGD self-assembly have been extensively studied making this protein a perfect model to study protein surface anisotropy and its role in directing protein assembly.
Cys-110 is the only surface exposed cysteine of HGD and hence responsible for covalent dimerization, a process that contributes to age-related cataract onset. However, the biological advantage of Cys-110 is not clear. Therefore, we mutated Cys to Met and Ser (C110M and C110S) and studied the mutant protein self-assembly. We found that C110S is recalcitrant to crystallization, while the mutant C110M crystallizes promptly; C110M crystals have the same characteristics as those of HGD, however, we suggest that the different nucleation behaviour of C110M may be due to subtle changes in the water shell of 110th site and its hydrophobicity. In conclusion, Cys-110 has the ability to suppress HGD crystallization; we speculate that the presence of Cys-110 is advantageous compared to either Met or Ser since Met enhances crystallization, hindering protein long-term stability, while Ser would decrease the HGD refractive index increment, which is essential for eye-lens function.
The effects of other single-point mutations on HGD self-assembly are known, for example R58H and R36S enhance crystallization, mutations at the 23rd site (e.g. P23V, P23T) induce the formation of retrograde solubility assemblies (i.e. they melt when cooled). It has been shown that the self-assembly behaviour of the double mutants P23VR36S, P23TR58H and P23VR58H can be predicted by those of the respective single mutants. To generalize this, we studied a novel double mutant, P23VC110M, that both enhances crystallization of the protein due to the C110M
mutation and at higher temperatures forms reversible assemblies with retrograde solubility due to the presence of the P23Vmutation. P23VC110M forms both these phases and a new polymorph, needle/plate-shaped crystals, which possibly arise from new crystal contacts involving the two mutation sites. Hence, we confirmed that the self-assembly of double mutants can be predicted from the behaviour of the respective single mutants, but also more complex scenarios can arise. We also examined the morphology of the retrograde solubility assemblies formed due to mutation P23V, which unusually are perfectly spherical. Using P23VC110M, we compared the properties of the amorphous, large, reversible and spherical assemblies to other forms of protein spherical superstructures, i.e. particulates and amyloid spherulites. P23VC110M spherical assemblies are not formed by amyloid fibrils but are amorphous and cannot be ascribed to any of the protein superstructures already known in literature. We therefore suggest that this is a new class of protein assembly.
The effect of surface modifications on protein self-assembly was then assessed for a novel type of Virus-like particle (VLP), ADDomer, based on Human Adenovirus serotype-3 (HAdv-3) penton-base protein. VLPs can be modified to display on their surface multiple copies of an epitope and hence trigger immune-response against a specific disease. However, vaccines often need to be stored in extremely cold conditions, which limits their distribution in remote areas of the world. We have studied the effects of temperature on different variations of ADDomer VLPs to understand the drivers for their self-assembly and their thermostabiliy. The thermal stability of ADDomer was compared to the one of a similar VLP, ChADDomer, derived from Chimpanzee Adenovirus serotype-3 (ChAdV-3); mutants L56C and S57C of ChADDomer were also designed to promote the formation of inter-penton disulphide bridges that could hinder VLP disassembly. A hybrid construct between ADDomer and ChADDomer, Chimera was also tested, along with its disulphide bridge-forming mutant S57C. We found that, of all the VLPs studied, ChADDomer S57C and L56C are the most thermally stable against aggregation and that disulphide-bridge promoting mutations also help stabilizing protein secondary structure. Conversely, ADDomer and Chimera abruptly aggregate. By structural comparison with ChADDomer, we identified the protein regions that may be responsible for this behaviour
Fine-tuning the spike: role of the nature and topology of the glycan shield in the structure and dynamics of the SARS-CoV-2 S
No full textThe dense glycan shield is an essential feature of the SARS-CoV-2 spike (S) architecture, key to immune evasion and to the activation of the prefusion conformation. Recent studies indicate that the occupancy and structures of the SARS-CoV-2 S glycans depend not only on the nature of the host cell, but also on the structural stability of the trimer; a point that raises important questions about the relative competence of different glycoforms. Moreover, the functional role of the glycan shield in the SARS-CoV-2 pathogenesis suggests that the evolution of the sites of glycosylation is potentially intertwined with the evolution of the protein sequence to affect optimal activity. Our results from multi-microsecond molecular dynamics simulations indicate that the type of glycosylation at N234, N165 and N343 greatly affects the stability of the receptor binding domain (RBD) open conformation, and thus its exposure and accessibility. Furthermore, our results suggest that the loss of glycosylation at N370, a newly acquired modification in the SARS-CoV-2 S glycan shield's topology, may have contributed to increase the SARS-CoV-2 infectivity as we find that N -glycosylation at N370 stabilizes the closed RBD conformation by binding a specific cleft on the RBD surface. We discuss how the absence of the N370 glycan in the SARS-CoV-2 S frees the RBD glycan binding cleft, which becomes available to bind cell-surface glycans, and potentially increases host cell surface localization. The N -glycans structures affect the mechanistic properties of the SARS-CoV-2 S, fine-tuning the glycoprotein. The evolution of the glycan shield led to the loss of N370 glycosylation in SARS-CoV-2 S, where the RBD cleft can bind host-cell glycans
Towards a Digital Twin of the Earth System: Geo-Soft-CoRe, a Geoscientific Software & Code Repository
No full textThe immense advances in computer power achieved in the last decades have had a significant
impact in Earth science, providing valuable research outputs that allow the simulation of complex
natural processes and systems, and generating improved forecasts. The development and
implementation of innovative geoscientific software is currently evolving towards a sustainable
and efficient development by integrating models of different aspects of the Earth system. This will
set the foundation for a future digital twin of the Earth. The codification and update of this
software require great effort from research groups and therefore, it needs to be preserved for its
reuse by future generations of geoscientists. Here, we report on Geo-Soft-CoRe, a Geoscientific
Software & Code Repository, hosted at the archive DIGITAL.CSIC. This is an open source,
multidisciplinary and multiscale collection of software and code developed to analyze different
aspects of the Earth system, encompassing tools to: 1) analyze climate variability; 2) assess
hazards, and 3) characterize the structure and dynamics of the solid Earth. Due to the broad
range of applications of these software packages, this collection is useful not only for basic
research in Earth science, but also for applied research and educational purposes, reducing the
gap between the geosciences and the society. By providing each software and code with a
permanent identifier (DOI), we ensure its self-sustainability and accomplish the FAIR (Findable,
Accessible, Interoperable and Reusable) principles. Therefore, we aim for a more transparent
science, transferring knowledge in an easier way to the geoscience community, and
encouraging an integrated use of computational infrastructure
The marketisation of education and the democratic deficit
No full textThis article deals with the question of what has happened to ‘the public’ in the Swedish education system during the last three decades. In our search for an answer we illuminate and discuss how the process of marketisation, together with the learnification and individualisation of education,
replaced ‘the public’ from public education with the logic of the market place. To shed some further light on the current discourse on Swedish education, we contrast two principles in education and teaching, the aristocratic principle and the democratic principle. According to
the aristocratic principle, education is about fixating and reproducing existing power relations as the cornerstone of a well-ordered society. According to the democratic principle of education, equality is the cornerstone of a well-ordered democratic society. Considering the shift in the very
infrastructure of the Swedish educational system, we arrive at the conclusion that the principles in education and teaching are characterised by the aristocratic principle, rather than those we have characterised as democratic principles. The educational message is clear: upcoming generations are to accept the rules of the market economy and play the game accordingly
Coverage Enhancement of Underwater Internet of Things Using Multilevel Acoustic Communication Networks
No full textUnderwater acoustic communication networks (UACNs) are considered a key enabler to the Underwater Internet of Things (UIoT). UACN is regarded as essential for various marine applications, such as monitoring, exploration, and trading. However, a large part of existing literature disregards the 3-D nature of the underwater communication system. In this article, we propose a K -tier UACN that acts as a gateway that connects the UIoT with the space–air–ground–sea integrated system (SAGSIS). The proposed network architecture consists of several tiers along the vertical direction with adjustable depths. On the horizontal dimension, the best coverage probability (CP) is computed and maximized by optimizing the densities of surface stations (SSs) in each tier. On the vertical dimension, the depth of each tier is also optimized to minimize intertier interference and maximize overall system performance. Using tools from stochastic geometry, the total CP of the proposed K -tier network is analyzed. For given spatial distribution of UIoT device’s depth, the best CP can be achieved by optimizing the depths of the transceivers connected to the SSs through a tether. We verify the accuracy of the analysis using Monte Carlo simulations. In addition, we draw multiple useful system-level insights that help optimize the design of underwater 3-D networks based on the given distribution of UIoT device’s depths
"Contrasts in Tolerance?": A cross-sectoral analysis of punitiveness in the adult and youth criminal justice systems of Ireland, Scotland and the Netherlands 1990-2015
No full textIncluded in tex
The KdmB-EcoA-RpdA-SntB chromatin complex binds regulatory genes and coordinates fungal development with mycotoxin synthesis
No full textChromatin complexes control a vast number of epigenetic developmental processes. Filamentous fungi present an important clade of microbes with poor understanding of underlying epigenetic mechanisms. Here, we describe a chromatin binding complex in the fungus Aspergillus nidulans composing of a H3K4 histone demethylase KdmB, a cohesin acetyltransferase (EcoA), a histone deacetylase (RpdA) and a histone reader/E3 ligase protein (SntB). In vitro and in vivo evidence demonstrate that this KERS complex is assembled from the EcoA-KdmB and SntB-RpdA heterodimers. KdmB and SntB play opposing roles in regulating the cellular levels and stability of EcoA, as KdmB prevents SntB-mediated degradation of EcoA. The KERS complex is recruited to transcription initiation start sites at active core promoters exerting promoter-specific transcriptional effects. Interestingly, deletion of any one of the KERS subunits results in a common negative effect on morphogenesis and production of secondary metabolites, molecules important for niche securement in filamentous fungi. Consequently, the entire mycotoxin sterigmatocystin gene cluster is downregulated and asexual development is reduced in the four KERS mutants. The elucidation of the recruitment of epigenetic regulators to chromatin via the KERS complex provides the first mechanistic, chromatin-based understanding of how development is connected with small molecule synthesis in fungi