Investigate if the mesh: prefix shall be defined in mesh.ttl

[filak]

https://github.com/filak/MTW-MeSH/blob/master/flask-app/instance/conf/mesh.ttl

  @prefix mesh:   <http://id.nlm.nih.gov/mesh/> .

[filak]

Probably not:

• mesh: prefix is not used anywhere in the mappings
• everything seems to be working fine as it is