This page lists specific source data elements and provides information on their representation in the UMLS Metathesaurus.
LCH_NW is a new source.
All files are available here: http://files.library.northwestern.edu/public/lcshmesh/
Additional documentation on the MARC 21 Format For Authority Data can be found here: http://www.loc.gov/marc/authority/
Documentation:
File |
Description |
---|---|
lcsh-mesh_read.doc | Description of the project and files |
lchs-mesh_sample.txt | Sample data |
Data:
File |
Description |
---|---|
lcsh.mrc | MARC 21 format authority file, with linking data to MSH strings |
The data is provided as a MARC 21 format authority file. Before Metathesaurus source processing, this file was converted to ascii using
MARC Tag/ Subfield |
Description |
Representation |
---|---|---|
010 $a |
Library of Congress Control Number | MRCONSO.CODE MRCONSO.SCUI MRMAP.FROMEXPR |
010 $z |
Canceled/invalid LC control number |
Not included in Metathesaurus source processing |
150, 151 $a $x $v $y $z |
Heading - Topical Term, Heading - Geographic Name name entry element general subdivision form subdivsion chronological subdivision geographical subdivision |
MRCONSO.STR CODE = Value of tag = 010, subfield $a TTY = PT SUPPRESS = N MRCONSO.STR is assembled by using "--" to concatenate the values of the $a, $x, $v, $y and $z subfields. |
750 $a |
Established Heading Linking Entry. A 2nd indicator value of "2" indicates a MSH mapping. |
MRREL.REL = RQ MRREL.RELA = mapped_from MRMAP.TOEXPR = SDUI of string of $a value Note: the original data in this field is populated by MSH strings. Where possible, the strings have been translated to MSH identfiers. In a small number of cases, the string provided did not correspond to a current MSH string, and these entries were dropped during Metathesaurus source processing. |
$x |
Indicates a MSH qualifier |
MRMAP.TOEXPR = MSH SDUI values, in the format "Descriptor Identifier/Qualifier Identifier" |
$8 |
field link/sequence number; indicates that one LCH concept maps to two or more MSH entity | MRMAP.TOEXPR = MSH SDUI values with the same sequence number, connected by "AND" MRMAP.TOTYPE = BOOLEAN_EXPRESSION_SDUI MRMAP.MAPRANK is incremented if there is more than one grouping (i.e. if the sequence number is incremented). |