The Experts below are selected from a list of 16689 Experts worldwide ranked by ideXlab platform
Valerie Hobbs - One of the best experts on this subject based on the ideXlab platform.
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complex knowledge modelling with Functional Entity relationship diagrams
Vine, 2011Co-Authors: Diarmuid Pigott, Valerie HobbsAbstract:Purpose – Modelling complex knowledge resources can be problematical as there is currently no formalism that can represent the nature of the data‐seeking process at a conceptual level. The purpose of this paper is to develop a knowledge representation formalism, the Functional Entity relationship diagram (FERD), which comprises a set of extensions to the industry standard Entity relationship diagram established by Chen.Design/methodology/approach – The research uses a design science approach to extend the existing ER formalism using the question‐answering (QA) paradigm. It is an extension of standard data modelling theory and is consistent with category theory.Findings – The authors defined the Functional Entity, an encapsulated data resource that acts as a QA system and enumerated a typology of nine Functional entities generated from two established principles to produce a modelling framework that can depict all existentially quantifiable relations, and demonstrated a satisficing extension to that framew...
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the Functional Entity relationship diagram conceptual modelling for complex knowledge systems
Pigott D. and Hobbs V.J. (2009) The functional-entity relationship diagram: conceptual modelling for complex knowledge systems. In: 20th Australasian , 2009Co-Authors: Diarmuid Pigott, Valerie HobbsAbstract:Designing and building a knowledge management system involves ensuring that the right facts can be called upon to answer the question at hand, and coordinating a number of disparate resources. Modelling such resources can be problematical as there is currently no formalism that can represent the nature of the dataseeking process at a conceptual level. We introduce the Functional Entity (FE), an encapsulated data resource that acts as a question-answering system, and identify nine different Functional entities based on three main types of question-answer entailment: instance-dominant, value-dominant, and connection-dominant. We use Functional entities to develop a generalisation of the Entity-Relationship Diagram (ERD), the Functional-Entity Relationship Diagram (FERD), which can be used for high level conceptual modelling of heterogeneous KM systems, and illustrate its use with a case study. We also show how the establishment of standard types of Functional Entity motivates practical guidelines for the conversion of the design to the implementation level.
Alex Thirifays - One of the best experts on this subject based on the ideXlab platform.
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cost model for digital preservation cost of digital migration
International Journal of Digital Curation, 2011Co-Authors: Ulla Bogvad Kejser, Anders Bo Nielsen, Alex ThirifaysAbstract:The Danish Ministry of Culture has funded a project to set up a model for costing preservation of digital materials held by national cultural heritage institutions. The overall objective of the project was to increase cost effectiveness of digital preservation activities and to provide a basis for comparing and estimating future cost requirements for digital preservation. In this study we describe an activity-based costing methodology for digital preservation based on the Open Archice Information System (OAIS) Reference Model. Within this framework, which we denote the Cost Model for Digital Preservation (CMDP), the focus is on costing the Functional Entity Preservation Planning from the OAIS and digital migration activities. In order to estimate these costs we have identified cost-critical activities by analysing the functions in the OAIS model and the flows between them. The analysis has been supplemented with findings from the literature, and our own knowledge and experience. The identified cost-critical activities have subsequently been deconstructed into measurable components, cost dependencies have been examined, and the resulting equations expressed in a spreadsheet. Currently the model can calculate the cost of different migration scenarios for a series of preservation formats for text, images, sound, video, geodata, and spreadsheets. In order to verify the model it has been tested on cost data from two different migration projects at the Danish National Archives (DNA). The study found that the OAIS model provides a sound overall framework for the cost breakdown, but that some functions need additional detailing in order to cost activities accurately. Running the two sets of empirical data showed among other things that the model underestimates the cost of manpower-intensive migration projects, while it reinstates an often underestimated cost, which is the cost of developing migration software. The model has proven useful for estimating the costs of preservation planning and digital migrations. However, more work is needed to refine the existing equations and include the other Functional entities of the OAIS model. Also the user-friendliness of the spreadsheet tool must be improved in future versions of the model. The CMDP is presently closing its second phase, where it has been extended to include the OAIS Functional Entity Ingest. This has also enabled us to adjust the theoretical model further, especially regarding the accuracy and precision of the model and in relation to the underlying parameters used in the equations, such as migration frequency and format complexity. Understanding the nature of digital preservation cost is prerequisite for increasing the overall efficiency, and achieving first quality for preservation of cultural heritage materials.
Cornelius Gati - One of the best experts on this subject based on the ideXlab platform.
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structural basis of the activation of a metabotropic gaba receptor
Nature, 2020Co-Authors: Hamidreza Shaye, Andrii Ishchenko, Jordy Homing Lam, Gye Won Han, Li Xue, Philippe Rondard, Jeanphilippe Pin, Vsevolod Katritch, Cornelius GatiAbstract:Metabotropic γ-aminobutyric acid receptors (GABAB) are involved in the modulation of synaptic responses in the central nervous system and have been implicated in neuropsychological conditions that range from addiction to psychosis1. GABAB belongs to class C of the G-protein-coupled receptors, and its Functional Entity comprises an obligate heterodimer that is composed of the GB1 and GB2 subunits2. Each subunit possesses an extracellular Venus flytrap domain, which is connected to a canonical seven-transmembrane domain. Here we present four cryo-electron microscopy structures of the human full-length GB1-GB2 heterodimer: one structure of its inactive apo state, two intermediate agonist-bound forms and an active form in which the heterodimer is bound to an agonist and a positive allosteric modulator. The structures reveal substantial differences, which shed light on the complex motions that underlie the unique activation mechanism of GABAB. Our results show that agonist binding leads to the closure of the Venus flytrap domain of GB1, triggering a series of transitions, first rearranging and bringing the two transmembrane domains into close contact along transmembrane helix 6 and ultimately inducing conformational rearrangements in the GB2 transmembrane domain via a lever-like mechanism to initiate downstream signalling. This active state is stabilized by a positive allosteric modulator binding at the transmembrane dimerization interface.
Diarmuid Pigott - One of the best experts on this subject based on the ideXlab platform.
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complex knowledge modelling with Functional Entity relationship diagrams
Vine, 2011Co-Authors: Diarmuid Pigott, Valerie HobbsAbstract:Purpose – Modelling complex knowledge resources can be problematical as there is currently no formalism that can represent the nature of the data‐seeking process at a conceptual level. The purpose of this paper is to develop a knowledge representation formalism, the Functional Entity relationship diagram (FERD), which comprises a set of extensions to the industry standard Entity relationship diagram established by Chen.Design/methodology/approach – The research uses a design science approach to extend the existing ER formalism using the question‐answering (QA) paradigm. It is an extension of standard data modelling theory and is consistent with category theory.Findings – The authors defined the Functional Entity, an encapsulated data resource that acts as a QA system and enumerated a typology of nine Functional entities generated from two established principles to produce a modelling framework that can depict all existentially quantifiable relations, and demonstrated a satisficing extension to that framew...
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the Functional Entity relationship diagram conceptual modelling for complex knowledge systems
Pigott D. and Hobbs V.J. (2009) The functional-entity relationship diagram: conceptual modelling for complex knowledge systems. In: 20th Australasian , 2009Co-Authors: Diarmuid Pigott, Valerie HobbsAbstract:Designing and building a knowledge management system involves ensuring that the right facts can be called upon to answer the question at hand, and coordinating a number of disparate resources. Modelling such resources can be problematical as there is currently no formalism that can represent the nature of the dataseeking process at a conceptual level. We introduce the Functional Entity (FE), an encapsulated data resource that acts as a question-answering system, and identify nine different Functional entities based on three main types of question-answer entailment: instance-dominant, value-dominant, and connection-dominant. We use Functional entities to develop a generalisation of the Entity-Relationship Diagram (ERD), the Functional-Entity Relationship Diagram (FERD), which can be used for high level conceptual modelling of heterogeneous KM systems, and illustrate its use with a case study. We also show how the establishment of standard types of Functional Entity motivates practical guidelines for the conversion of the design to the implementation level.
Xu Song - One of the best experts on this subject based on the ideXlab platform.
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Multidimensional crosstalk between RNA-binding proteins and noncoding RNAs in cancer biology.
Seminars in cancer biology, 2021Co-Authors: Hui Miao, Yanbo Chang, Hong Yao, Yongyun Zhao, Xu SongAbstract:Abstract RNA-binding proteins (RBPs) are well-known to bind RNA via a set of RNA-binding domains (RBDs) and determine the fate and function of their RNA targets; inversely, some RBPs, in certain cases, may be modulated by the bound RNAs rather than regulate their RNA partners. Current proteome-wide studies reveal that almost half of RBPs have no canonical RBDs, and the discovery of tens of thousands of noncoding RNAs (ncRNAs), especially those with the size larger than 200 nt (namely long noncoding RNAs, lncRNAs), makes the crosstalk between RBPs and RNAs more complicated. It is clear that macromolecular complexes formed by RBP and RNA are not only a form of existence of their RBP and RNA components in cells, but also represent a Functional Entity through which those RBPs and regulatory ncRNAs participate in the construction of regulatory networks in organism. In this review, we summarize the multidimensional crosstalk between RBPs and ncRNAs in cancer and discuss how RBPs achieve their function via the bound ncRNAs in different aspects of gene expression as well as how RBPs direct modification and processing of ncRNAs, in order to better understand tumor biology and provide new insights into development of strategies for cancer therapy and early detection.
