Search

Abstract This study investigated a marker-assisted introgression programme in Australian Merino sheep. The goal was to introgress an allele with a large negative effect on fibre diameter into a Merino flock possessing medium average fibre diameter. The influence of two factors was explored: the strategy used to select animals from the purebred and backcross line for backcrossing purposes and the use of selection on background markers to accelerate the return to the purebred line's genome. The results were compared to introgression based on EBVs only. Introgression using EBVs only produced almost the same response in the dollar index as marker-based introgression methods. However, this study did not account for some of the costs associated with implementing the programmes, including the costs of phenotyping and genotyping. Given that the cost of measuring fibre diameter is low, it was concluded that introgression on EBVs only would be the preferred method since the marginal profit of marker-assisted introgression would not be large enough to cover the additional cost of genotyping. In marker-assisted introgression, reciprocal crossing of male and female selection candidates from the backcross and the purebred line was the most advantageous strategy from a practical and profit point of view. Selection for background markers was less profitable in this study than recovering the donor genome by selection on phenotype.

Sunnybrook Medical Centre, Toronto, has designed a written, multidisciplinary program of care for elderly patients in acute care. The program includes specific community outreach activities that support the in-hospital program and addresses the challenges presented by an increasingly aged population. Some of its objectives are to develop a measurement for length of stay patterns, a reduction in the number of patients waiting for relocation to a long-term care institution (commonly and derogatorily referred to as "placement problems") and an increase in patient, family and staff satisfaction. A method for program evaluation is being designed. The program takes a three-level approach to care: (1) the non-problematic elderly patient, (2) the more complex elderly patient and (3) the care of patients who have finished treatment for their acute illness but who require long-term care institutionalization.