public function rulersperiodAction()
 {
     if ($this->_getParam('term', false)) {
         $rulers = new Rulers();
         $response = $rulers->getAllRulers($this->_getParam('term'));
     } else {
         $response = array(array('id' => NULL, 'term' => 'No period specified.'));
     }
     echo Zend_Json::encode($response);
 }