About: http://webisa.webdatacommons.org/359800978

Property	Value
http://www.w3.org/1999/02/22-rdf-syntax-ns#type	http://www.w3.org/ns/prov#Entity
http://www.w3.org/ns/prov#value	Second, it is difficult to perform absolute, calibrated measurements of quantities such as blood flow and volume due to unknown optical properties of tissues.
http://www.w3.org/ns/prov#wasQuotedFrom	spie.org