How to change widget titles within Admin widgets panel?

Hi,

I'd like to know if there is a way to change widgets titles within Admin widgets panel (in multisite).

For example, one widget for the WPMUdev Google+ plugin has the following title: "Google+ Imported activities". I can't find this string in the po. file.

I know Ultimate branding allow me to change texts network wide but this is not a perfect solution so I'd like to avoid it for this point.

Best Regards