You can refresh the channels by clicking on the Refresh button in the toolbar. This will generate channel episodes when they are available (depending on how often you want to generate the episodes as set in the channel settings). You can also refresh by selecting the Refresh option or pressing ⌘R.
You can also set News Anchor to refresh channels automatically on startup or even refresh channels when it is not running. Simply select Preferences from News Anchor’s application menu (the pull down menu item just to the right of the Apple menu) and enable both checkboxes as shown below.
If you’re running Mac OS X10.7 “Lion” and downloaded News Anchor from the Mac App Store then News Anchor will need to be running to refresh channels. That is the Refresh when News Anchor is not running option is not available when you use the App Store version on Lion. This is due to Apple’s sandboxing restriction that applies to all Mac App Store applications.
Note that you will need to have a working Internet connection to refresh channel episodes.