Question: Which senators have as their official symbol "per aspera ad astra" in 2013?
Answer(s):
answer: Pat Roberts
answer: Jerry Moran

SPARQL query:
PREFIX ns: <http://rdf.freebase.com/ns/>
SELECT DISTINCT ?x
WHERE {
FILTER (?x != ?c)
FILTER (!isLiteral(?x) OR lang(?x) = '' OR langMatches(lang(?x), 'en'))
?c ns:government.governmental_jurisdiction.official_symbols ?k .
?k ns:location.location_symbol_relationship.symbol ns:m.03d17dt . 
?c ns:government.political_district.representatives ?y .
?y ns:government.government_position_held.office_holder ?x .
?y ns:government.government_position_held.basic_title ns:m.048zv9l .
FILTER(NOT EXISTS {?y ns:government.government_position_held.from ?sk0} || 
EXISTS {?y ns:government.government_position_held.from ?sk1 . 
FILTER(xsd:datetime(?sk1) <= "2013-12-31"^^xsd:dateTime) })
FILTER(NOT EXISTS {?y ns:government.government_position_held.to ?sk2} || 
EXISTS {?y ns:government.government_position_held.to ?sk3 . 
FILTER(xsd:datetime(?sk3) >= "2013-01-01"^^xsd:dateTime) })
}