Among the major policy choices commonly adopted in East Asia, and noticeably less so elsewhere in the developing world are openness to foreign trade, significant levels of government savings and an emphasis on education for both boys and girls. While these attributes were far from universally applied, they are conspicuously present in the region to a much larger degree than is the case elsewhere. Tree frog  A tree frog is any species of frog that spends a major portion of its lifespan in trees, known as an arboreal state. Several lineages of frogs among the Neobatrachia have given rise to tree frogs, although they are not closely related to each other. Millions of years of convergent evolution have resulted in very similar morphology even in species that aren't very closely related. As the name implies, these frogs are typically found in trees or other high-growing vegetation. They do not normally descend to the ground, except to mate and spawn, though some build foam nests on leaves and rarely leave the trees at all as adults. Many tree frogs can change their color for better camouflage. For instance, the grey tree frog ("Hyla versicolor") can change its color from green to grey to yellow. Tree frogs are usually tiny as their weight has to be carried by the branches and twigs in their habitats. While some reach 10 cm (4 in) or more, they are typically smaller and more slender than terrestrial frogs. Tree frogs typically have well-developed discs at the finger and toe tips; the fingers and toes themselves, as well as the limbs, tend to be rather small, resulting in a superior grasping ability. The genus "Chiromantis" of the Rhacophoridae is most extreme in this respect: it can oppose two fingers to the other two, resulting in a vise-like grip. Tree frogs are members of these families or genera:      Surgical planning  The surgical planning is the preoperative method of pre-visualising a surgical intervention, in order to predefine the surgical steps and furthermore the bone segment navigation in the context of computer-assisted surgery. The surgical planning is most important in neurosurgery and oral and maxillofacial surgery. The transfer of the surgical planning to the patient is generally made using a medical navigation system. The imagistic dataset used for surgical planning is mainly based on a CT or MRI. In oral and maxillofacial surgery, a different, more "traditional" surgical planning can be used for orthognatic surgery, based on cast models fixed into an articulator.