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.
Answer: Virtually all spiders are predatory on other animals, especially insects and other spiders. Very large spiders are capable of preying on small vertebrate animals such as lizards, frogs, fish, tadpoles, or even small snakes or baby rodents. Large orb weavers have been observed to occasionally ensnare small birds or bats.