Find the angle between the vectors \(\mathbf{u} = \begin{pmatrix} 4 \\ -2 \\ 1 \end{pmatrix}\) and \(\mathbf{v} = \begin{pmatrix} 1 \\ 1 \\ -3 \end{pmatrix}\) in degrees. Let's think step by step and output the final answer within \boxed{}.
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