Surcingle the withers area. It usually has padding to relieve pressure on the horse's spine. A variation of this design is used for equestrian vaulting. Many trainers first teach a young horse to accept girth pressure by strapping on a surcingle before a saddle and girth. The surcingle is commonly used for longeing, often as a base from which to attach training equipment such as side reins, overcheck, lauffer reins (sliding side reins), or chambons. A surcingle is also important in long lining or ground driving, as it provides rings for the long reins to run through. Double longeing, using two
Animal testing on frogs which reaches its reproductive age in five months rather than one to two years (as in "X. laevis"), facilitating faster studies across generations. The genome sequence of "X. tropicalis" was scheduled to be completed by 2015 at the latest. Frogs are widely used in classroom dissections and teaching exercises. Animal testing on frogs Frogs have been used in animal tests throughout the history of biomedical science. Eighteenth-century biologist Luigi Galvani discovered the link between electricity and the nervous system through studying frogs. The African clawed frog or platanna, "Xenopus laevis", was first widely used in laboratories in pregnancy assays in