Their system extracts the embryo outline by using an adaptive thresholding method (Peng and Myers, 2004), and registers the embryo using affine transformation and intensity scaling.
After having sacrificed herself to kill the Alien Queen gestating inside her in Alien 3, Ripley has been cloned using blood samples so that the military may extract the Queen embryo.
The new rules were issued last August; they permit federally financed scientists to experiment with cell lines derived from embryos, so long as those scientists do not extract the cells from embryos themselves.
President Bush's aides are now reviewing a rule, issued by the Clinton administration last August, that would give government money to scientists studying stem cells, as long as taxpayer money is not used to extract the cells from embryos.
But their source is a matter of fierce moral debate, because they are taken from human life that has been deliberately destroyed--usually through abortions or in laboratories that extract the cells from embryos produced at fertility clinics and donated by parents who no longer want them.
At the stage known as the blastocyst, from which embryonic stem cells must be extracted, the early embryo does not have even a rudimentary nervous system.
"The stem-cell debate is not converting or changing anyone's idea of where life begins," she says, "but advocates of the Bush policy are saying that the evil [destruction of the embryos to extract the stem cells] has already been done, and we can make use of it.
The agency's researchers themselves would not be allowed to extract the cells from discarded embryos.
But scientists cannot use federal money to extract the stem cells from human embryos.
But the next step in his research — using human embryonic stem cells — is ineligible for federal money because, up to now, the technology requires the destruction of human embryos to extract the stem cells.
