1,721,154 research outputs found
Navigation in Hypermedia Applications: Modeling and Semantics
No full textNavigation - browsing from one related piece of information to another - is an important means of accessing information for a large class of applications: hypermedia, object-oriented databases, multimedia databases, and even traditional systems. In this article, we discuss a variety of sophisticated navigation paradigms. We distinguish among free, guided tour, and history-based navigation. In addition, we discuss integrating pure browsing with query-based access. We discuss static and dynamic models of the various navigation patterns, highlighting the fact that defining an adequate browing semantics requires a data model and a runtime model, both of which are more complex than those commonly found in hypermedia or databases. We illustrate these concepts with examples from a real-life banking application
Modelling the bioinformatics tertiary analysis research process
Full text linkBackground: With the advancements of Next Generation Techniques, a tremendous amount of genomic information has been made available to be analyzed by means of computational methods. Bioinformatics Tertiary Analysis is a complex multidisciplinary process that represents the final step of the whole bioinformatics analysis pipeline. Despite the popularity of the subject, the Bioinformatics Tertiary Analysis process has not yet been specified in a systematic way. The lack of a reference model results into a plethora of technological tools that are designed mostly on the data and not on the human process involved in Tertiary Analysis, making such systems difficult to use and to integrate. Methods: To address this problem, we propose a conceptual model that captures the salient characteristics of the research methods and human tasks involved in Bioinformatics Tertiary Analysis. The model is grounded on a user study that involved bioinformatics specialists for the elicitation of a hierarchical task tree representing the Tertiary Analysis process. The outcome was refined and validated using the results of a vast survey of the literature reporting examples of Bioinformatics Tertiary Analysis activities. Results: The final hierarchical task tree was then converted into an ontological representation using an ontology standard formalism. The results of our research provides a reference process model for Tertiary Analysis that can be used both to analyze and to compare existing tools, or to design new tools. Conclusions: To highlight the potential of our approach and to exemplify its concrete applications, we describe a new bioinformatics tool and how the proposed process model informed its design
User Interaction Styles in Museum Hypermedia
No full textThis paper will analyse a variety of interaction styles that can be designed in hypermedia applications, will point out the need of using them consistently, and will analyze the possible design trade-offs between richness of interaction and easiness of use. Examples will be taken from a museum hypermedia we are currently developing in co-operation with the Poldi Pezzoli Museum in Milano
Technical Aspects of Extracorporeal Ultrafiltration: Mechanisms, Monitoring and Dedicated Technology
No full textFluid overload may occur in patients with heart failure. Further complications may arise when cardiorenal syndromes develop and the kidneys are unable to eliminate the accumulated fluid. Diuretics represent the fist line of treatment, although in some case they may be ineffective or even dangerous for the patient. In these conditions, extracorporeal ultrafiltration may be required. Extracorporeal ultrafiltration can be performed continuously or intermittently, using dedicated machines. The goal is to remove the right amount of fluid without causing hemodynamic instability or further ischemia to the kidneys. For this purpose, special technologies are available and they can be utilized in combination to prevent iatrogenic complications. First of all, a complete analysis of heart and kidney function should be carried out. Then, an evaluation of biomarkers of heart failure and a careful analysis of body fluid composition by bioimpedance vector analysis should be carried out to establish the level of hydration and to guide fluid removal strategies. Last but not least, an adequate extracorporeal technique should be employed to remove excess fluid. Preference should be given to continuous forms of ultrafiltration (slow continuous ultrafiltration, continuous venovenous hemofiltration); these techniques guided by a continuous monitoring of circulating blood volume allow for an adequate restoration of body fluid composition minimizing hemodynamic complications and worsening of renal function especially during episodes of acute decompensated heart failure. Copyright (C) 2010 S. Karger AG, Base
Dynamic Hemodialysis: A Potential Solution for Middle Molecule Removal
No full textBetter clearance of middle molecular weight solutes has been associated with improved patient outcomes. However, blood-membrane interaction during dialysis results in the development of secondary protein layers on the dialysis membrane surface, leading to impairments in middle molecular weight solute removal. The shear rate at the surface of the dialysis membrane is one of the important factors that influence blood-membrane surface interaction. In this paper, we discuss the concept of 'dynamic hemodialysis', i.e. using mechanical vibration to increase shear rate at the surface of dialysis membrane. For longitudinal and transverse vibratory motions, hemodynamic changes inside the membrane and their consequent effects on membrane morphology and dialysis efficiency are discussed. Longitudinal vibration generates a reverse flow by relative membrane motion, and transverse vibration generates a symmetric swirling flow inside the hollow fiber, which increases shear rate and enhances flow mixing. Additionally, the impulse induced by the vibration could sustain the absorption capacity of the membrane to specific uremic toxins. In conclusion, dynamic hemodialysis could enhance solute removal by minimizing the morphological changes in the dialysis membrane during hemodialysis. However, the operating conditions of dynamic hemodialysis (i.e. the amplitude and frequency of mechanical vibration) need to be optimized in terms of hemolysis and noise from the mechanical vibration. Copyright (C) 2011 S. Karger AG, Base
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