Test for Upper Case – T-Sql

Using collations

eg:

if ('a'='A' Collate Latin1_General_CI_AI) 
    print'same 1'
else
    print 'different 1'

if ('a'='A' Collate Latin1_General_CS_AI) 
    print'same 2'
else
    print 'different 2' 

The CS in the collation name indicates Case Sensitive (and CI, Case Insensitive). The AI/AS relates to accent sensitivity.

or in your example

SUBSTRING(author,1,1) <> LOWER(SUBSTRING(author,1,1)) COLLATE Latin1_General_CS_AI