A perspective for biomedical data integration: Design of databases for flow cytometry

<p>Abstract</p> <p>Background</p> <p>The integration of biomedical information is essential for tackling medical problems. We describe a data model in the domain of flow cytometry (FC) allowing for massive management, analysis and integration with other laboratory and clinical information. The paper is concerned with the proper translation of the Flow Cytometry Standard (FCS) into a relational database schema, in a way that facilitates end users at either doing research on FC or studying specific cases of patients undergone FC analysis</p> <p>Results</p> <p>The proposed database schema provides integration of data originating from diverse acquisition settings, organized in a way that allows syntactically simple queries that provide results significantly faster than the conventional implementations of the FCS standard. The proposed schema can potentially achieve up to 8 orders of magnitude reduction in query complexity and up to 2 orders of magnitude reduction in response time for data originating from flow cytometers that record 256 colours. This is mainly achieved by managing to maintain an almost constant number of data-mining procedures regardless of the size and complexity of the stored information.</p> <p>Conclusion</p> <p>It is evident that using single-file data storage standards for the design of databases without any structural transformations significantly limits the flexibility of databases. Analysis of the requirements of a specific domain for integration and massive data processing can provide the necessary schema modifications that will unlock the additional functionality of a relational database.</p

Towards an evaluation of accident investigation methods in terms of their alignment with accident causation models

The purpose of this paper is to reflect on accident causation models and accident investigation methods. Theories on accident causation and the modelling of accident mechanisms, as well as a number of methods for accident investigation have been developed and described in the literature. The evolution of accident causation models over time shows a shift from the sequence of events to the representation of the whole system. Respectively, the evolution of accident investigation methods over time reveals a gradual shift from searching for a single immediate cause, to the recognition of multiple causes. In order to evaluate the accident investigation methods, specific plausible requirements were established in order to verify that a specific accident investigation method fulfils the principles of a specific accident causation model or give evidence to the degree of alignment between them. Since different models approach accident causation in different ways, methods linked to these models provide fragmentary information regarding the accident. It is therefore expected that using a combination of model-method pairs could provide a more reliable platform for accident analysis

Removal of pollutants from poor quality coals by pyrolysis

Combustion of poor quality coals and wastes is used today worldwide for energy production. However, this entails significant environmental risks due to the presence of polluting compounds in them, i. e. S, N, Hg, and Cl. In the complex environment of combustion these substances are forming conventional (i. e. SOx, NOx) and toxic (PCDD/Fs) pollutants, while, the highly toxic Hg is volatilized in the gas phase mainly as elemental mercury. Aiming to meet the recently adopted strict environmental standards, and the need of affordable in cost clean power production, a preventive fuels pre-treatment technique, based on low temperature carbonization, has been tested. Clean coals were produced from two poor quality Greek coals (Ptolemais and Megalopolis) and an Australian coal sample, in a lab-scale fixed bed reactor under helium atmosphere and ambient pressure. The effect of carbonization temperature (200-900 °C) and residence time (5-120 minutes) on the properties of the chars, obtained after pyrolysis, was investigated. Special attention was paid to the removal of pollutants such as S, N, Hg, and Cl. To account for possible mineral matter effects, mainly on sulphur removal, tests were also performed with demineralized coal. Reactivity variation of produced clean coals was evaluated by performing non-isothermal combustion tests in a TA Q600 thermo gravimetric analyzer. Results showed that the low temperature carbonization technique might contribute to clean coal production by effectively removing the major part of the existing polluting compounds contained in coal. Therefore, depending on coal type, nitrogen, mercury, and chlorine abatement continuously increases with temperature, while sulphur removal seems to reach a plateau above 500-600 °C. More-over, the prolongation of carbonization time above 20 minutes does not affect the elemental conversion of the pollutants and carbonization at 500-600 °C for ~20 minutes may be considered sufficient for clean coal production from poor quality coals. Clean coal production at higher pyrolysis temperatures results in observed higher initial combustion temperature, mainly due to lower volatile content in produced chars