While significant research efforts have broadened the understanding of toxicity of QDs, there are large discrepancies in the literature and questions still remains to be answered. Diversity of this class material as compared to normal chemical substances makes the assessment of their toxicity very challenging. As their toxicity may also be dynamic depending on the environmental factors such as pH level, light exposure and cell type, traditional methods of assessing toxicity of chemicals such as LD 50 are not applicable for QDs. Therefore, researchers are focusing on introducing novel approaches and adapting existing methods to include this unique class of materials.  Furthermore, novel strategies to engineer safer QDs are still under exploration by the scientific community. A recent novelty in the field is the discovery of carbon quantum dots , a new generation of optically-active nanoparticles potentially capable of replacing semiconductor QDs, but with the advantage of much lower toxicity.
New Guinea was first sighted by Spanish and Portuguese sailors in the early 16th century and was known prophetically as Isla del Oro (Island of Gold). The western part of the island was claimed by Spain in 1545 and named New Guinea for a fancied resemblance of the people to those on the West African coast. ("Papua" is a Malay word for the typically frizzled quality of Melanesian hair.) Traders began to appear in the islands in the 1850s, and the Germans sought coconut oil available in northern New Guinea about that time. The Dutch and the British had earlier agreed on a division of their interests in the island, and from 1828, the Dutch began to colonize the western portion.