I have a rdf file that looks like this:
<rdf:Description rdf:about="http://sentic.net/api/en/concept/a_little">
<rdf:type rdf:resource="http://sentic.net/api/concept"/>
<text xmlns="http://sentic.net/api">a little</text>
<semantics xmlns="http://sentic.net/api" rdf:resource="http://sentic.net/api/en/concept/least"/>
<semantics xmlns="http://sentic.net/api" rdf:resource="http://sentic.net/api/en/concept/little"/>
<semantics xmlns="http://sentic.net/api" rdf:resource="http://sentic.net/api/en/concept/small_amount"/>
<semantics xmlns="http://sentic.net/api" rdf:resource="http://sentic.net/api/en/concept/shortage"/>
<semantics xmlns="http://sentic.net/api" rdf:resource="http://sentic.net/api/en/concept/scarce"/>
<pleasantness xmlns="http://sentic.net/api" rdf:datatype="http://www.w3.org/2001/XMLSchema#float">-0.99</pleasantness>
<attention xmlns="http://sentic.net/api" rdf:datatype="http://www.w3.org/2001/XMLSchema#float">0</attention>
<sensitivity xmlns="http://sentic.net/api" rdf:datatype="http://www.w3.org/2001/XMLSchema#float">0</sensitivity>
<aptitude xmlns="http://sentic.net/api" rdf:datatype="http://www.w3.org/2001/XMLSchema#float">-0.709</aptitude>
<polarity xmlns="http://sentic.net/api" rdf:datatype="http://www.w3.org/2001/XMLSchema#float">-0.566</polarity>
</rdf:Description>
How can I get the object of e.g. the predicate 'polarity' (i.e. -0.566 in this case)?