You are leaking your PR to these other websites, and if not opening in a new window, you're increasing your bounce rate and lowering the time spent on your site.
7 to 8 outbound links on an article is a tremendous drain of your internal PR and could also send Google the false signal that you are selling links since they are dofollow.
I would remove outgoing links, if you need them as references then nofollow them and target="_blank" them. You are still losing some PR with nofollowing them, but Google can read them and still see that you are linking to them if that is your intention. I would allow Google, FB links for example to be dofollow, but would no follow lesser known sites.