此脚本列出了用户的最后一篇文章。如何将一些作者排除在guery之外？

<?php

    //List of users sorted descending by date of lastest post written by user
    $uc=array();
    $blogusers = get_users_of_blog();

    if ($blogusers) 
    {
        foreach ($blogusers as $bloguser) 
        {
            $user = new WP_User( $bloguser->user_id );
            if ( !empty( $user->roles ) && is_array( $user->roles ) )
            {
                $userpost = get_posts(\'showposts=1&author=\'.$bloguser->user_id);
                $uc[$bloguser->user_id] = \'\';
                if ($userpost) 
                {
                    $uc[$bloguser->user_id]=$userpost[0]->post_date;
                }
            }
        }
        arsort($uc);
        $i = 0;
        foreach ($uc as $key => $value) 
        {
            $user = get_userdata($key);
            $post_count = count_user_posts($user->ID);
            if ($post_count && $i < 10) 
            {
                $author_posts_url = get_author_posts_url($key);

                //preparing query for titles
                $args=array(
                \'author\' => $user->ID ,
                \'post_type\' => \'post\',
                \'post_status\' => \'publish\',
                \'posts_per_page\' => 1,
                \'ignore_sticky_posts\'=> 1,
                );
                $my_query = null;
                $my_query = new WP_Query($args);

                if( $my_query->have_posts() ) 
                {
                    //echo \'List of Posts for \' . user->user_firstname . \' \' . $user->user_lastname;
                    while ($my_query->have_posts()) : $my_query->the_post(); 

?>