[R-sig-Geo] Getting regression coefficients when universal kriging

[Steinbuch, Luc]

Suppose I have this  (working) code:

library(gstat) 
library(rgdal) 
library(raster) 

data(meuse) 
coordinates(meuse) = ~x+y 
r <- raster(system.file("external/test.grd", package="raster")) 
projection(r)<-projection(meuse) 
names(r) = 'elev' 

vu<-variogram(log(zinc)~elev,meuse) 
mu<-fit.variogram(vu,vgm(1,"Sph",300,1)) 
gUK<-gstat(NULL,"log.zinc",log(zinc)~elev,meuse,model=mu) 
UK<-interpolate(r, gUK, xyOnly=FALSE)

How do I find the finally used regression parameters, calculated by the universal kriging function of 'interpolate'?