Executives of 3D Systems (DDD), in a conference call with analysts early Monday, defended the company's accounting practices in response to critical articles that caused the company's shares to fall. "Let me be clear for the avoidance of any doubt, that we stand behind all our public disclosures and filings and believe that in all respects we're using the correct accounting methods," said 3D CEO Abe Reichental, according to a transcript of the