To estimate the impact of differing technical weights on multiple traits a selection index model was used.
A number of selection scenarios were investigated by altering the set of technical weights used, in order to illustrate the trade-offs in gain between the traits (Figures 1, 2 and 3).
As such, the gain comparisons among the various scenarios using the technical weights from the general Smith-Hazel index (which is operating as a mass selection index) do not directly apply when applying the same weights to the tree breeding values from mixed-model analysis.
Technical weights were multiplied by the individual-tree breeding values, as calculated by Eq. 1.
b is the column vector of index weights 1, 2…n; P is the phenotypic variance-covariance matrix; G is the genotypic variance-covariance matrix; b is the column vector of technical weights.
The weights applied to the model were altered for each trait to achieve the desired, or close to the desired, gain for the suite of traits under selection (i.e., they are considered technical weights).
While the desired technical weights, derived from the traditional mass-selection index approach, cannot be directly applied to multivariate BLUP breeding values (and yield the same levels of genetic gains) they do provide an important 'starting point' for further sensitivity evaluations.
An index model was constructed in Microsoft Excel software based on the traditional 'Smith-Hazel' index model (Cotterill and Dean [1990]) to explore the dynamics of selecting for the KTs and NKTs when different technical weights (level of importance) were imposed.
WHEN Transportation Secretary Ray LaHood told a Congressional committee Tuesday, "We are looking at the possibility of recommending the brake override system in all newly manufactured automobiles," he was giving weight to a technical solution to sudden acceleration that is on only some cars.
To provide a technical overview, the applied methodologies were systematically decomposed to identify weighting and scoring techniques.
