(Arabian horse breeding activity not engaged in for profit, thus losses not fully deductible; taxpayer had no experience in caring for and riding horses and no experience in the buying, selling or showing of horses and presented no evidence that she had consulted anyone regarding the economic or business aspects of breeding, training or showing horses; taxpayer paid both personal and horse activity expenses from same two or three personal checking accounts; no written business plan created; no financial projections maintained; no expectation of future increase in value of assets; taxpayer had high income as a physician and received a great deal of personal pleasure from the activity).