select * from logging as lg join user as u on u.user_name = replace(log_title, '_', ' ') 

    where lg.log_type = 'block' and exists 

        (select 1 from user_groups as ug

            where ug.ug_user = u.user_id and ug.ug_group = 'sysop'

        )

        and lg.log_timestamp >= '2016-01-01' 

        order by lg.log_timestamp desc;