901 research outputs found
Comprehending 3D and 4D ontology-driven conceptual models: An empirical study
This paper presents an empirical study that investigates the extent to which the pragmatic quality of ontology-driven models is influenced by the choice of a particular ontology, given a certain understanding of that ontology. To this end, we analyzed previous research efforts and distilled three hypotheses based on different metaphysical characteristics. An experiment based on two foundational ontologies (UFO and BORO) involving 158 participants was then carried out, followed by a protocol analysis to gain further insights into the results of experiment. We then extracted five derivations from the results of the empirical study in order to summarize our findings. Overall, the results confirm that the choice of a foundational ontology can lead to significant differences in the interpretation and comprehension of the conceptual models produced. Moreover, the effect of applying a certain foundational ontology can cause considerable variations in the effort required to comprehend these models
Endurant Types in Ontology-Driven Conceptual Modeling: Towards OntoUML 2.0
For over a decade now, a community of researchers has contributed
to the development of the Unified Foundational Ontology (UFO)
- aimed at providing foundations for all major conceptual modeling constructs.
This ontology has led to the development of an Ontology-Driven
Conceptual Modeling language dubbed OntoUML, reflecting the ontological
micro-theories comprising UFO. Over the years, UFO and OntoUML
have been successfully employed in a number of academic, industrial and
governmental settings to create conceptual models in a variety of different
domains. These experiences have pointed out to opportunities of
improvement not only to the language itself but also to its underlying
theory. In this paper, we take the first step in that direction by revising
the theory of types in UFO in response to empirical evidence. The
new version of this theory shows that many of the meta-types present
in OntoUML (differentiating Kinds, Roles, Phases, Mixins, etc.) should
be considered not as restricted to Substantial types but instead should
be applied to model Endurant Types in general, including Relator types,
Quality types and Mode types. We also contribute a formal characterization
of this fragment of the theory, which is then used to advance a
metamodel for OntoUML 2.0. Finally, we propose a computational support
tool implementing this updated metamodel
Falerii novi (comune di fabrica di Roma, provincia di viterbo, regione lazio)
As part of the AHRC-funded “Beneath the Surface of Roman Republican Cities” project (2015-17), our team is pursuing a full-coverage Ground Penetrating Radar (GPR) survey of the entire intra-mural area of the Roman town of Falerii Novi, in combination with an assessment of the unpublished pottery from the excavations of 1969-75: our objective is to further our knowledge and understanding of the Roman town and its earlier phases of settlement (Launaro et al. 2016; 2017)
The use of confocal microscopy in quantifying changes in membrane potential
Monitoring the plasma membrane potential and its changes can be a time consuming and challenging task especially when conventional electrophysiological techniques are used. The use of potentiometricfluorophores, namely tetramethylrhodamine methylester (TMRM), and digital imaging devices (laser scanning confocal microscopy) provides reliable and time efficient method. Two scorpion pore-forming peptides, namely PP and OP1, were used as a tool to induce depolarization of the plasma membrane potential of neuroblastoma cell line and cardiac myocytes. Alternative methods for the neuroblastoma cells and cardiac myocytes were used. Depolarization of the neuroblastoma cells was calibrated with 140 mM KCl solution with 1 ìM valinomycin, after which intensity readers were substituted in the Nernst equation for quantification. Calibration of the alternative method used of the cardiac myocytes’ plasma membrane potential changes was calibrated with the use of 5, 20, 40, and 80 mM KCl solutions with 1 ìM valinomycin. A calibration curve was then constructed from which plasma membrane potential could be calculate
The age-dependent expression of the F18(+) E.coli receptor on porcine gut epithelial cells is positively correlated with the presence of histo-blood group antigens
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Interamna lirenas and its territory (comune di pignataro interamna, provincia di frosinone, regione lazio)
The archaeological fieldwork at Interamna Lirenas is part of an integrated research project involving geophysical prospection, field survey and excavation, all aimed at exploring the long-term development of the Roman town and its territory from its colonial origin (late 4th c. BC) well into Late Antiquity (6th c. AD) (Bellini, Launaro and Millett 2014). The full coverage Ground Penetrating Radar (GPR) survey of the urban area (in collaboration with Ghent University) and the main excavation of the roofed theatre (theatrum tectum) were brought to completion in the course of the eighth fieldwork season (2017)
Lactoferrin inhibits E. coli O157: H7 growth and attachment to intestinal epithelial cells
Enterohemorrhagic Escherichia coli (EHEC) serotype O157:H7 strains are associated with haemorraghic colitis and haemolytic uremic syndrome (HUS) in humans. Cattle are a reservoir of E. coli O157:H7. We studied the ability of bovine and human lactoferrin, two natural antimicrobial proteins present in milk, to inhibit E. coli O157:H7 growth and attachment to a human epithelial colorectal adenocarcinoma cell line (Caco-2). The direct antibacterial effect of bLF on E. coli O157:H7 was stronger than that of hLF. Nevertheless, both lactoferrins had bacteriostatic effects even at high concentrations (10 mg/ml), suggesting blocking of LF activity by a yet undefined bacterial defence mechanism. Additionally, both lactoferrins significantly inhibited E. coli O157:H7 attachment to Caco-2 cells. However, hLF was more effective than bLF, probably due to more efficient binding of bLF to intelectin present on human enterocytes leading to uptake and thus removal of bLF from the extracellular environment. Inhibition of bacterial attachment to Caco-2 cells was at least partly due to the catalytic effect of lactoferrins on the type III secreted proteins EspA and Esp
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