An important discovery was the finding that sirenomelia was an invariable phenotypic trait in the double Bmp7 Tsg (Twisted gastrulation) mutant mouse (Zakin et al., 2005).
Mass, then, is not thought an invariable property of matter.
But these changes in body composition, he added, "are not an invariable accompaniment of aging".
And when a president is elected, there is an invariable tendency however short-lived to rally round the victor.
"Realistically, we do not expect our performance to follow an invariable trend line upward," he said in a written statement.
He has an invariable answer to questions about his age, the date of his graduation or the age of his daughter: "Confidential".
But Kurt Volker, who served the Bush and Obama administrations as ambassador to NATO, made what looks like an invariable point.
Such feelings may be generated by muscular effort; exhaustion of the energy supply to the muscles of the body, however, is not an invariable precursor.
We saw the players' faces in newspaper photographs, or in the pages of Baseball, an engrossing monthly with an invariable red cover, to which I subscribed, and here and there in an advertisement.
In an effort to dispel the out-of-date idea that anonymity of authorship is an invariable characteristic of Indian art, the curators have identified by name all of the 40 painters whose work is gathered here.
In the IPCP, an invariable channel in at least two adjacent periods is assumed.
