Targeting custom post type

You can make use of get_post_type( $post ) to check whether a post belongs to a certain post type

Inside your loop, you can do the following check

while ($my_query->have_posts()) : $my_query->the_post();

if ( 'activists' == get_post_type() ) {

    /* Custom code for 'activists' post type. */

} else {

    /* Custom code for the other post types. */
}

endwhile; wp_reset_query();