hiː hɐz spˈɛnt ðə ɹˈɛst ʌv hɪz kɚɹˈɪɹ æɾ ˈaɪəwə stˈeɪt jˌuːnɪvˈɜːsᵻɾi, æz ɐn ɐsˈɪstənt pɹəfˈɛsɚ fɹʌm nˈaɪntiːnhˈʌndɹɪd ˈeɪɾi sˈɛvən tə nˈaɪntiːnhˈʌndɹɪd nˈaɪnti tˈuː, ɐsˈoʊsɪˌeɪt pɹəfˈɛsɚ fɹʌm nˈaɪntiːnhˈʌndɹɪd nˈaɪnti tˈuː tə nˈaɪntiːnhˈʌndɹɪd nˈaɪnti sˈɪks, ænd fˈʊl pɹəfˈɛsɚ sˈɪns nˈaɪntiːnhˈʌndɹɪd nˈaɪnti sˈɪks.
He has spent the rest of his career at Iowa State University, as an assistant professor from 1987 to 1992, associate professor from 1992 to 1996, and full professor since 1996.