\usepackage{newtxtext,newtxmath}
\usepackage{etoolbox}
\newcommand{\headlinestyle}{\itshape\huge}
\newcommand{\bylinestyle}{\scshape\Large}
\patchcmd{\headline}{#1}{\headlinestyle #1}{}{}
\patchcmd{\byline}{#1}{\bylinestyle #1}{}{}