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SRS Introductory Course5/12/2002
- Temporary and permanent sessions- Simple querying- Browsing indices- Standard and extended query forms- User defined views
http://srs.ebi.ac.uk
Temporary session
Permanentsession
DatabaseInformation-which are present-when indexed
Documentation
List of public servers
Temporary Projects• Queries and views are stored by the project manager
temporarily
• Temporary sessions last 24 hours
• Useful when you:
– Do not need to keep your results
– look something up quickly
– Run an occasional application
• Click on ‘Start’ paw on SRS start page
Permanent Projects• Queries and views are stored by the project manager in a single
location
• They are available for use in the future
• Useful when:
– You want to return to a session
– Want to have many projects in the same session
• Begin by clicking ‘Permanent session’ paw on SRS start page
– Just need to enter an SRS user name and re-enter this to return to same session again later
SRS main toolbar tabs
• Top Page: displays databases in different database groups
• Query: displays either the standard or extended query form
• Results or “the query manager”: maintains a history of all the results obtained during a session
• Projects or “the project manager”: maintains a history of all queries and views used during a session
• Views: allows a user to define a user specific view for one or more databases
• Databanks: contains a list and some facts about the databases available in the system
Search terms in SRS
• SRS indexed fields can be searched using any of the following:
– Single word search
– Multiple word phrases
– Numbers and dates
– Regular expressions
– Wildcards
Search methods
• Quick search button:– Works by searching all datafields of type text – The quickest way to generate query results– For very general/broad searches
• Example: get all mouse and mouse related proteins in SWISS-PROT
• All Entries button:– Returns all entries in the database selected
• Search forms : allow you to specify your area of interest in more detail– Standard query form– Extended query form
Standard query form• Enter up to 4 separate search terms against up to 4 datafields
simultaneously
• Combine entries with logical operators ( and & or | butnot ! )
• Choose the number of entries to display per page
• Retrieve entries of type (entry or subentry(name))
• Choose a view – use an SRS predefined view
– create one of your own by selecting specific fields from a dropdown menu (and choose whether to view a list or table in SRS7)
Extended query form
• Can enter search terms for as many fields as you want• Combine searches with logical operators ( and & or | butnot ! )• Choose how many results to display per page• Choose view and sequence format to use
– Can choose an SRS predefined view– Define your own view by clicking the boxes next to the fields that
you want to have displayed (list or table option in SRS7)• Each field name has a hyperlink to the description page for that field• Form provides less than ‘<‘ and greater than ‘>’ for numerical fields• Choose what type of entries to retrieve (entry, subentry (name))
– on extended form if you query a subentry field, it defaults to returning results of type subentry
Differences in these 2 forms
• Ranges
– standard must use ‘:’
– extended provides ‘<‘ and ‘>’
• Type retrieval
– standard defaults to retrieving entries of type ‘entry’
– extended defaults to retrieving entries of type entry unless you query a subentry field in which case the default is the subentry type
• Controlled vocabulary fields
– standard does not provide you with a list for these fields
– extended provides a drop down menu for these fields allowing you to select an option
Wildcards• These are useful when:
– Searching for a group of words (eg. Words starting ‘cell’ and ending ‘ase’ : cell*ase)
– If unclear about how a word is spelt in a database
• Two types:
– * one or more characters of any value
– ? Single character of any value
• Any number of wildcards can be placed anywhere in a search word
• Placing a wildcard at the start of a word or string may increase response time because all words in the index have to be checked against the string
Regular expressions
• NB: Must appear within forward slashes (/)
• Some operators:
^ marks the start of a string /^glu/ begins with ‘glu’
$ marks the end of a string /ase$/ ends with ‘ase’
. dot is any single character
[…] characters in square brackets are regarded as a set, any of which can be matched
[0-9] specifies a range of 1 to 9
* the preceding group may be repeated zero or more times
+ the preceding group may be repeated one or more times
? The preceding character/group occurs one or zero times
Some examples/^glu/ will find terms beginning with ‘glu’
/ase$/ will find terms ending with ‘ase’
/c.t/ will find the words cat, cot, cut…….
/c.*t/ will find terms beginning with ‘c’ and
then any number of characters and ending with ‘t’
/sm[iy]th/ will find the words ‘smith’ or ‘smyth’
/rho[1-9]/ will find the word ‘rho’ followed by a number from 1-9
/mue?ller/ will find ‘muller’ or ‘mueller’
NB. The ‘*’ symbol has two meanings:
-within forward slashes ‘/’ it means the preceding group may be
repeated zero or more times
- outside forward slashes it means any character
Numerical ranges• In a numerical index it is possible to search numerical ranges - sequence lengths, mol. weights, dates….• the ‘:’ is used for specifying ranges and ‘!’ for excluding values
– 400:500 all seq. with length between 400 and 500– 400: all seq. with lengths greater than 400– :500 all seq. with lengths less than 500– 400:!500 all seq. with lengths bet. 400 and 500 excluding 500
• Can combine ranges using logical operators– 300:!400 | !500:600 or 300:600 ! 400:500
• Dates in SRS have 2 formats:– YYYYMMDD 20021205– DD-MMM-YYYY 05-Dec-2002
Some examples
– Find entries with sequences having length betwwen 300 and 400 excluding 400 and between 500 and 600 excluding 500: 300:!400 | !500:600 or 300:600 ! 400:500
– Find entries that were created in the first half of 2001:• 01-jan-2001:30-jun-2001 or 20010101:20010630
– Find all entries updated since May this year:• 01-may-2002: or 20020501:
SRS Indexing• SRS indexes database records using a ‘word by
word’ approach.- DE Human glutathione transferase
- The SRS description index will contain terms ‘human’, ‘glutathione’ and ‘transferase’.
• (&) AND : ‘human & glutathione & transferase’
• (|) OR : ‘human | glutathione | transferase’
• (!) BUTNOT : ‘human ! glutathione ! transferase’
EMBL
HUMANglutathione
transferase
human & glutathione & transferase
human & transferase ! glutathione gluthathione & transferase ! human
Databanks information page
• Lists the databases available in the system and a summary about them:
– Number of entries in the database
– Date it was indexed
– Group it belongs to
– Its availability status
• Hyperlinks to information page specific to each database
Database information page• Provides a detailed description about the database contents, source, ftp site,
literature…• Lists information about the fields that are present in the database including:
– Name of field– Short name for field– Type of field
• index : it is indexed• num : indexed and a numerical field• id: unique field• show: not indexed, just for display
– Number of keys for that field– Date it was indexed
• Lists databases that it is linked to and how many entries are linked respectively
Browsing indices
• This gives information on what is being indexed for a particular field– Single words, multiple words, controlled vocabulary…..
• To browse an index go to the information page for a particular field from a certain database– If you want to look at all indexed terms use ‘*’
– If you want all terms beginning with trans use ‘trans*’
– If you want all terms containing the string trans use ‘*trans*’
• Implicit wildcards are not automatically appended to the search terms when browsing indices and must be specified explicitly
Query manager
• Found under the results tab
• Saves a history of results obtained in the session
• Page allows you to return to previous results and:
– Combine them using logical operators – thus allowing you to perform a multistep query
– Use a different view to display them
– Perform further actions link, save, delete
Project manager
• Found under the projects tab
• Saves a history of queries performed in the session
• Can upload/download SRS session files from a desktop
• In a permanent session, the project manager can also:
– Manage numerous SRS projects at the same time
– Move queries/views between projects
– Upload/download projects to desktop
– Delete projects
User owned databanks
• Found in the category ‘user owned databanks’ on top page
• User can upload their own nucleotide or protein sequence data into a user owned database
– sequences must be in fasta format
– any number of sequences can be uploaded
– database is specific to the individual and to the session
• Can launch applications on database sequences
•Paste or upload a file•Fasta formatted files•Any number of sequences•Maintained throughout user session
Operations on results
• Linking : link results to other databases
• Saving: save results in different formats to the browser or a file
• Viewing: view results using different formats
• Sequence analysis: launch applications on the results • SRS6 – 11 protein applications, 6 nucleic acid apps.
• SRS7 – more than 100 applications available
SRS6 versus SRS7• SRS7 provides over 100 applications while SRS6 provides
17
• Sorting results in ascending or descending order is available
in SRS7 for a number of fields
• You can retrieve results in either list or table format in SRS7
• In SRS6 only the table format is available
• The external server will be upgraded to SRS7 very shortly
Sorting results in SRS7
• Perform after query has been executed
• Separate sort indices for specific fields
• Can order results in ascending or descending order
• Sorting available for : accession, gene name, description, dates, organism, organelle, sequence length
• Available for protein (internal and external) databases at present and will be provided for EMBL when the external server is upgraded to SRS7