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.
Why do spiders spin webs? How do spiders create webs? How long does it take a spider to build a web? How strong is a spider web? Why is spider silk sticky? What else do spiders use silk for? Spider Bites. What is the most venomous spider in the world? How do I treat a spider bite? What do spider bites look like? Reproduction. When do spiders lay eggs? How do spiders reproduce? How many eggs do spiders lay?