ViRexx Medical Corp. (TSX:VIR) says chief financial officer Rob Salmon has left the company to pursue other opportunities. Marc Canton, president and chief operating officer, has assumed CFO responsibilities on an acting basis.

ViRexx is an Edmonton-based biotechnology company focused on treatments of certain cancers and chronic viral infections.

Melanie van den Berge has resigned her position as vice-president and director of Catapult Energy 2004 Inc. to pursue other interests.

CFO Joanne Hruska will take on an expanded role in the operations of Catapult.

Calgary-based Catapult is a wholly owned subsidiary of Overlord Financial Inc., a developer of Canadian specialty financial products.

Titan Logix Corp. has made two appointments.

Greg McGillis is the new VP of business and product development, and Ron Markowski the new VP of sales and marketing.

McGillis joined Titan in 1992, working in various capacities. Markowski recently joined Titan Logix as the sales and marketing manager.

Titan Logix (TSXV:TLA) is an emerging technology company based in Edmonton.

Defiant Resources Corp. (TSX:DFR) has made some corporate changes.

David Evans has handed over the function of CEO to Rick Ironside. Evans remains chairman of the board.

Ironside, previously president and chief operating officer, retains the president's position.

Tim Dunne has handed over his responsibilities as VP of finance and CFO to Rob Solinger in order to pursue other interests, but is now a company director. Most recently, Solinger was part-owner of a private oil and gas company before its recent sale.

Arne Hamarsnes has become VP of operations. Arne has been with Defiant and its predecessor company for three years, most recently as manager of operations. Defiant is a Calgary-based independent junior natural gas and oil producer.

Tusk Energy Corp. has made some changes in its executive suite.

Norman Holton has been appointed CEO and will continue as chairman of the board of directors of Tusk. Ian Brown, the former president and CEO of Tusk, will continue his association with Tusk in an advisory role.

Holton was president, CEO and founder of Tusk Energy Inc., the predecessor company to Tusk Energy Corp., and chairman and CEO of TKE Energy Trust since November 2004.

Earl Hickok becomes president and chief operating officer. Prior to this appointment he was president, CEO and founder of Tecskor Corp. and a member of the Tusk board of directors.

Tusk (TSX:TSK) is a Calgary-based exploration company focused on natural gas and oil reserves in the northwest part of the Western Canada Sedimentary Basin.

Calpine Power Income Fund (TSX:CF.UN) has named Geoff Krause to VP and CFO of Calgary-based Calpine Canada Power Ltd., the manager of the fund.

Prior to taking on this role Krause worked for various energy companies in Canada and Mexico.

Decision Dynamics Technology Ltd. (TSXV:DDY) has appointed Mark Amelang as executive VP of sales. Amelang will be located in the company's Houston office.

Prior to joining Decision Dynamics, he held positions with EMC Corp. and Auspex Systems, Inc.

Decision Dynamics develops data capture, reporting and business analytics services for the energy industry. Its corporate headquarters are in Calgary.

Colin Porter has joined Good Earth Coffeehouse and Bakery in the newly created position of regional operations manager. Most recently he was an operations manager for the Hilton Hotel chain in the United Kingdom.

Good Earth is a Calgary-based group of cafes that currently owns and operates eight cafes in Calgary.

Leader Energy Services Ltd. (TSXV:LEE) has made two executive additions to its cementing services division.

Jeff Melnyk becomes VP of operations and general manager of cementing services. Melnyk joined Leader in March 2005 and will be overseeing all aspects of the cementing division.

Beerd Beekman becomes VP of engineering and operations manager for cementing services, and will focus on establishing the laboratory, blend development and technical sales. Prior to joining Leader, Beekman was employed by Trican Well Service.

Leader provides field services for oil and gas well stimulation from locations in Grande Prairie, Red Deer and Hinton, and plans to provide cementing services starting in 2006.

The Institute of Chartered Accountants of Alberta (ICAA) has appointed Jane Halford of Edmonton to the position of CEO and executive director. She succeeds Steve Glover, who served as executive director from 1984 to 2005.

 with files from The Canadian Press (To submit your appointments, corporate changes or photos, e-mail news@businessedge.ca)