\begin{table}%t4 \par \caption {\label{tab:abundances}Element source abundances for Model~III-C and comparison with HEAO-3 results.} %\centerline { \begin{tabular}{ccll}\hline\hline $Z$ & Element & $ 10^{22}\times q_Z$ & ~~~~~HEAO-3 \\ & & ~(m$^3$~s~GeV/n)$^{-1}$ & (Engelmann et al.)\\\hline 6 & C & $148.5 \pm 3. $ & $164.9 \pm 4.7 $\\ 7 & N & $ 8.1 \pm 0.6 $ & $ 9.9 \pm 3.4 $\\ 8 & O & $185. \pm 3. $ & $204. \pm 2.2 $\\ 9 & F & $ 3.67~\pm 0.05 $ & $ 3.67~\pm 0.05 $\\ 10 & Ne & $ 24.1 \pm 0.4 $ & $22.5 \pm 1.3 $\\ 11 & Na & $ 1.88 \pm 0.08 $ & $ 1.25 \pm 0.5 $\\ 12 & Mg & $ 40.3 \pm 0.6 $ & $ 40.3 \pm 1.0 $\\ 13 & Al & $ 3.69~\pm 0.1 $ & $ 3.02 \pm 0.6 $\\ 14 & Si & $ {\bf 38.8} \pm 0.5 $ & $ {\bf 38.8} \pm 0.5 $\\ \hline \end{tabular}} \par \smallskip Note 3: {Isotopic fractions of elements $q_i/q_Z$ are fixed to Solar System ones \citep{2003ApJ...591.1220L} and $q_Z\equiv\sum_{i=\rm isot.} q_i$. The best-fit value is obtained from the best-fit model (on B/C), where source abundances were rescaled to match HEAO-3 data at 10.6~GeV/n. The uncertainty in $q_Z$ originates from the same rescaling, but arising from all combinations of parameters satisfying the~68\% CL on the $\chi^2$ distribution. For HEAO-3, the numbers are taken from Table~7 of \citet{1990AetA...233...96E}, and have been rescaled to $q_Z({\rm Si})=38.8\times10^{-22}$~(m$^3$~s~GeV/n)$^{-1}$ (boldface) to ease the comparison.} \end{table}