public function getLatestArtifactsCount($numDayInterval = 3) {
        $strQ = <<<EOF
SELECT COUNT(id) FROM artifacts.item
WHERE
add_timestamp >= (current_date - :day_interval)::timestamp AND
is_imported = FALSE AND
is_public = TRUE AND
is_removed = FALSE;
EOF;

    $objSth = $this->objDb->prepare($strQ);
    $objSth->execute(array(
        ':day_interval' => $numDayInterval
    ));
    $numArtifactsCount = $objSth->fetchColumn();
    return $numArtifactsCount;
    }