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The Representation of Scientific Data. Frank.Gibson@ncl.ac.uk. Overview. Recording archiving and sharing the process and the results of experimental data is a challenge What to store? How to store it? Why?. Science is complicated. Technology. Complex experimental workflow
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The Representation of Scientific Data Frank.Gibson@ncl.ac.uk
Overview • Recording archiving and sharing the process and the results of experimental data is a challenge What to store? How to store it? Why?
Technology • Complex experimental workflow • Advances in instrumentation • High-through methods
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Analysis • New algorithms and software • Data integration • From multiple sources • Genomics • Proteomics • Metabolomics • Neuroscience • Systems biology
Problems • “In the standard model, one collects data, publishes a paper or papers and then gradually loses the original dataset.” • THE NEW KNOWLEDGE ECONOMY AND SCIENCE AND TECHNOLOGY POLICYGeoffrey Bowker, University of California, San Diego
Problems • Large, complex datasets are commonplace, • Heterogeneous data formats • Vendor specific, Lab specific • Multitude of analysis methods • Proprietary, open source
Benefits • Knowledge discovery – results • Sharing of best practice • Evaluation of results • Sharing of data • Re-use
Re-use of neuroscience datasets • Data that is shared and can be interpreted can often be used to address multiple questions. • Data that have been collected with one question in mind often turn out to be highly valuable to address other questions • (1) Hippocampus recordings for mapping place fields were the basis for high-profile papers addressing questions concerning temporal organization of neural codes (PMID: 12891358 ). • (2) Paired recordings using extracellular and intracellular electrodes originally collected for detecting dendritically generated action potentials provide ground truth for testing and comparing spike-sorting techniques (PMID: 10899214 ).
Engineering and Physical Sciences Research Council CARMENCode, Analysis, Repository and Modelling for e-Neurosciencewww.carmen.org.uk
Virtual Laboratory for Neurophysiology • Enabling sharing and collaborative exploitation of data, analysis code and expertise that are not physically collocated
Cost • Infrastructure • Acquisition – data and metadata • Developing a common representation • Potential benefits are not always experienced by data producers • Lab experimenter vs bioinformatician
Data pyramid Results Processing Derived data Raw data
Mass Spectrometry Data pyramid Results Processing Derived data Raw data
How do we store the data? • Dictated by form of access • Raw data, typically vendor specific formats for vendor specific software analysis • Derived data – unlimited formats – higher level of access required to determine results • Results – often queries over derived data • Problematic if derived data are represented in inconsistent structures • – consistent representation is valuable
Metadata • Description of results • Sample • How it was generated • Equipment • Processing steps • Expensive to capture • Important to validate result Lab-book Lab-book Lab-book Lab-book Lab-book Lab-book Lab-book Lab-book Lab-book
Standards • Science is a challenge • Scientific data is complex • Different data representations add further complexity to complex science • We need a common representation of data to get back to just complex science • Lots of individuals have created formats in isolation – only works for their data in their lab
What is a standard? • “established by consensus and approved by a recognized body, that provides, for common and repeated use, rules, guidelines or characteristics for activities or their results, aimed at the achievement of the optimum degree of order in a given context“ • BSI - • http://www.bsi-global.com/en/Standards-and-Publications/About-standards/Glossary/
Standards: allow working together for knowledge discovery Knowledge
Standards bodies • W3C -World wide web consortium (W3C) • IEEE - Institute of Electrical and Electronics Engineers • OMG – Object management group
Technologies for data standards • Important to adopt a technology that provides a clear representation of the domain • The model and the model documentation capture a shared understanding of the domain • Many technologies exist which support modelling • Each focuses on a different use such a validation, code generation and data transmission
Technologies being used • Simple text documents or spreadsheets • XML - Extensible Markup Language • RDF – Resource Description Framework • UML – Unified Modeling Language • OWL – Web ontology Language • OBO – Open Biomedical Ontology format
Simple documents • A list of what is required • MIxxx Minimum information XXX • MIAME • Minimum information about a Microarray Experiment • MAIPE • Minimum information about a Proteomics Experiment
MIAPE:GE • Identifies the minimum information required to report the use of n-dimensional gel electrophoresis in a proteomics experiment
XML • Widely used for representing biological information • Mark up sections with elements • Validates against a schema <lecture> <to>Bioinformatics students</to> <from>Frank Gibson</from> <title>Representation of scientific data </title> <feedback>Students all fell asleep </feedback> </lecture>
UML • An implementation independent model • Allows multiple technology implementations of the same model • Such as • XML, JAVA, Relational tables
The numbers indicate the multiplicity of the relationship with * meaning “many”. One or more instances of JetEngine can be associated with one or more instances of Aeroplane A filled diamond indicates containment. An Aeroplane can not exist without a JetEngine An arrow shows the direction of the relationship. An open-headed arrow indicates inheritance. A Pilot and a Passenger are both instances of Person, inheriting the attributes “name” and “DOB”. 1..* 1..*
Functional Genomics Experiment (FuGE) • Model of common components in science investigations, such as materials, data, protocols, equipment and software. • Provides a framework for capturing complete laboratory workflows, enabling the integration of pre-existing data formats.
RDF • Overcomes limited expressivity of XML • Allows the semantic meaning of statements to be captured
Ontolgies for Life science • Emergence has occurred for two reasons • Consistent annotation of data • To add meaning and understanding that can be interpreted computationaly • Bio-ontologies registered on the OBO foundry
Bio-ontologies • OBO format • Flat file format, more suited to controlled vocabularies, made popular by GO • OWL • W3C recommendation, designed for computers not humans
sepCV In OBO
OBI • An ontology for all investigations in the life sciences • Implemented in OWL • Large community involvement • sepCV to be integrated within OBI
Tools • Tools are important • Biologist don’t want to look at XML • Need data entry tools – a website… • Direct export of data and metadata from instruments • Equipment vendors and manufactures need to be involved in the “community” of standards development • Tools lag behind development of the standard
The Representation of Scientific Data The Road Map
Patience • Standards development is slow it requires • A measure of technical and political consensus • An organisational framework • Individuals who are willing to contribute time and expertise, both domain experts and knowledge engineers (modellers)
The Problem • Identify the problem • Identify the users that need the problem solved • Requirements gathering – what do the users need? • See if someone else has already done it! • If so, use it and go to the pub