The phrase "is a locus" is grammatically correct and can be used in written English.
It means "is a place or location where something can be found or occurs." Example: The library is a locus for knowledge and learning.
For one character, Paris is "a locus of several desires".
Sri Lanka is a locus of guerrilla war and arms smuggling.
But in the long term, the internet is a locus of power: for organizing, for rallying, for raising awareness, for calling out oppression, for offering solace to others.
Alfred Hitchcock, Nicholas Ray, John Cassavetes, Otto Preminger are justly considered consummate artists; "The Man Who Shot Liberty Valance" is a locus classicus of the political cinema.
CÉDRIC TIBERGHIEN The Frick Collection is a locus for up-and-coming European musicians making their New York débuts.
FULTON STREET in Bedford-Stuyvesant is a locus for hundreds of stops, especially at its busy intersection with Nostrand Avenue.
The HbVar database is a locus-specific database of human haemoglobin variants and thalassemias [ 35].
In contrast, because adaptive evolution is a locus-specific force, repeated bouts of positive selection due to local adaptation should result in extreme reductions in polymorphism only at selected loci.
The AD&FTLD Mutation Database is a locus-specific database (LSDB) that was conceived in 1998 [Cruts and Van Broeckhoven, 1998b] in the perspective of the Mutation Database Initiative [Cotton et al., 1998], an initiative originally fostered by the Human Genome Organization (www.hugo-international.org) that has through the years evolved to the Human Genome Variation Society (HGVS, www.hgvs.org).hgvs.org
Within this region, 9p21.3 is a loci approximately 22 million base pairs from the 9p telomere.
Until then, whales had been a locus of fearful wonder, or an industrial resource.
