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.
Quick Answer. Diving bell spiders of the species Argyroneta aquatica have the ability to swim, and they use this adaptation to live underwater. Although they live and swim in the water, diving bell spiders still breathe air by creating air pockets underwater that they use as homes. Continue Reading.
All spiders can be considered deadly to their prey, but from a human perspective, only a small number of species pose any consistent threat to life and limb. Two prime candidates for the most dangerously venomous spiders to people are the âBrazilian wandering spiderâ (Phoneutria spp.) and the âSydney funnelweb spiderâ (Atrax robustus). The âBrazilian wandering spider,â from Central and South America, can be very defensive when threatened. These spiders can get fairly large (4-5 inch leg span) and are sometimes encountered in the United States and Canada in fruit shipments, especially bananas.