As in other mammals, thermoregulation is an important aspect of human homeostasis. Most body heat is generated in the deep organs, especially the liver, brain, and heart, and in contraction of skeletal muscles. Humans have been able to adapt to a great diversity of climates, including hot humid and hot arid.
Japanese knotweed is a perennial weed, producing tall canes, up to 2.1m (7ft) in height during the summer. The canes have characteristic purple flecks, and produce branches from nodes along its length. These branches support shovel-shaped leaves.
One common stilbene found in Japanese knotweed is resveratrol, which is 3,5,4'-Trihydroxystilbene. Resveratrol has two isomers: cis and trans, with the latter being the most abundant. Piceid, also known polydatin, is a glucoside form of resveratrol found in Japanese knotweed. Emodin is an anthraquinone derivative that occurs in extracts of knotweed (Vastano et al., 2000) and other plant species.