The MRI scanner measures this signal difference and displays the activity as a colored area (Figure 1). Diffusion Tensor Imaging (DTI) is a technique that detects how water travels along the white matter tracts in the brain (Figure 2). White-matter tracts connect different parts of the brain and must be protected during surgery. A dye (contrast agent) may be injected into your blood stream.
Dock spiders can swim. A dock spider can actually swim under water and stay submerged for several minutes. It uses air bubbles trapped in the fine hairs on its body under its belly to provide oxygen while it is under water â a bit like a dock spider scuba dive. Dock spiders walk on water.
Bold Jumper Spider. The jumping spiders, as a rule, are relatively small, compact hunting spiders. They have very good eyesight and can pounce on their victims from a great distance. Spiders in the genus Phidippus are the largest-bodied of the Salticids. Phidippus audax, the most commonly encountered jumping spider in and around Pennsylvania homes, is found from Canada and the Atlantic Coast states west to California.