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.
Huntsman spiders(Sparassidae family)Huntsman spiders are widespread in Australia. They are famous for being the bit (up to 15cm leg-span) scary, hairy, black spiders bolting out from behind the curtains. In reality, they are reluctant to bite and more likely to run away when approached and their venom isn't considered dangerous for humans. Their danger comes more from causing accidents by the terrified drivers who react to a huntsman jumping out from behind the sun visor or dashboard of a car when it's in motion. Despite their intimidating size, huntsman spiders can be an ally in the house; they help with pest-control by eating smaller insects.