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.
This fascinating arthropod, also known as the water spider, is quite similar to other spiders in that it breaths air, although it does it in a much more creative way. These spiders spin a web cocoon of silk which they then fill up with air creating a bubble that they can take with them underwater. And due to a mostly sedentary life this spider is able to make the most of its oxygen only needing to come up about once a day or even less to replenish its air supply.
Camel spiders are tricky creatures. These desert arachnids look like they have ten legs, but two of these limbs are really pedipalps, sensors that help them locate prey. Theyâre called spiders, but theyâre not part of the same order of species as a tarantula or a wolf spider. Instead of fangs, they have powerful jaws.