Department of Statistical Science, Duke University, Durham, North Carolina, USA.|Department of Statistical Science, Duke University, Durham, North Carolina, USA.|Department of Statistical Science, Duke University, Durham, North Carolina, USA.|Department of Statistical Science, Duke University, Durham, North Carolina, USA.|Department of Statistical Science, Duke University, Durham, North Carolina, USA.|Department of Statistical Science, Duke University, Durham, North Carolina, USA.|Department of Statistical Science, Duke University, Durham, North Carolina, USA.|Department of Statistical Science, Duke University, Durham, North Carolina, USA.|Department of Statistical Science, Duke University, Durham, North Carolina, USA.|Department of Statistical Science, Duke University, Durham, North Carolina, USA.