Trade beads Trade beads Trade beads (sometimes called aggry and slave beads) were otherwise decorative glass beads used between the 16th and 20th century as a token money to exchange for goods, services and slaves (hence the name). Trade beads were used to African resources by early Europeans. This included African slave trade. The beads were integrated in Native American jewelry using various beadwork techniques. Aggry beads are a particular type of decorated glass bead from Ghana. Made to ease the passage of European explorers and then traders mainly across the African continents, the beads were made throughout Europe although the Venetians
Shell-less chick embryo culture Shell-less chick embryo culture Shell-less chick embryo culture is the process of growing chick embryos "in vitro", without their protective egg shells, for scientific observation. Chick embryos and other avian embryos have been biological models to visualize the developmental stages of embryos for education and to instigate embryological manipulations. Using this technique, observations can be made, whether it is a induced-malformation caused due to effect of teratogens or the route of viruses inoculations such as HIV or herpes simplex. Furthermore, preservation of endangered avian and development of transgenic birds using surrogate egg shell culture have been contrived by scientists across