What part of speech is the underlined word in the following sentence from paragraph 1?

What led to the westernization and annexation of hawaii?

The procedures for reporting potential unanticipated problems involving risk to subjects or others to the irb are: stated in the human subject protection regulations, but not in the drug or device regulationsincluded in the consent processdetermined by research staffdetermined by the institution in its written policies and procedures

Humans are the only animals capable of communication