Mister Spex, a Germany-based online optician which is backed by investors including multi-corporate fund Xange Capital, has appointed former Selfridges CEO Peter Williams as chairman.

Violin Memory, a flash memory company backed by Toshiba, SAP and Juniper Networks, has lost both its CEO and its COO, as its shares trade at below half its IPO price.

Germany-based mobile games developer sets up advisory board including Thomas Grota of T-Venture.

Yet2Ventures' Ben duPont is now chairman of portfolio company Mobeam, a mobile commerce point of sale (POS) technology provider.

For Mawsonia, the publishing company behind Global Corporate Venturing and Global University Venturing, we have been following this advice since our launch in 2010 and I am glad to now welcome Dominic Riley as our chairman.

He previously held the same role at Vela Systems, which sold to Autodesk last year, and Eleven Technologies, acquired by Trimble Navigation in 2006.

In April last year, Wittlebee raised $2.5m in its seed round from Google Ventures and venture capital firms Crosslink Capital and Rincon Venture Partners.