Aside from the diamond, the ruby, sapphire, emerald, pearl (not, strictly speaking, a gemstone) and opal have also been considered to be precious. Up to the discoveries of bulk amethyst in Brazil in the 19th century, amethyst was considered a precious stone as well, going back to ancient Greece.
A restriction map is a map of known restriction sites within a sequence of DNA. Restriction mapping requires the use of restriction enzymes.In molecular biology, restriction maps are used as a reference to engineer plasmids or other relatively short pieces of DNA, and sometimes for longer genomic DNA.ased on the sizes of the resultant DNA fragments the positions of the sites can be inferred. Restriction mapping is a very useful technique when used for determining the orientation of an insert in a cloning vector, by mapping the position of an off-center restriction site in the insert (Dale, Von Schantz, 2003).
Brain mapping may be done during surgery with the patient awake, using medication to keep the person relaxed and pain-free. This is done so that the patient can help the surgeon find and avoid areas of the brain responsible for vital functions.