Daniel Chapman Stillson Daniel Chapman Stillson Daniel Chapman Stillson (March 25, 1826 - August 23, 1899) was an American inventor. He invented the modern adjustable pipe wrench. He was born March 25, 1826 in Durham, New Hampshire. He was the son of William Stillson and Nancy Chapman. He married Ellen Raynes Davis on April 18, 1855. He was a machinist during the American Civil War and served on David Glasgow Farraguts first voyage as a vice admiral. At the end of the Civil War, Stillson returned to Charlestown, Massachusetts, and eventually he moved to Somerville, Massachusetts. He then worked as a machinist at
Transposons as a genetic tool The recent discovery of the 'mariner transposon' (from the reconstruction of the original sequence from many 'dead' versions in the human genome) has allowed many new experiments, mariner has well conserved homologues across a wide range of species and is a very versatile tool. Transposons as a genetic tool Transposons are semi-parasitic DNA sequences which can replicate and spread through the host's genome. They can be harnessed as a genetic tool for analysis of gene and protein function. The use of transposons is well-developed in "Drosophila" (in which P elements are most commonly used) and in Thale cress ("Arabidopsis thaliana")