Oryza sativa wet-rice cultivation as early as 2200 BC has been discovered at both Ban Chiang and Ban Prasat in Thailand. By the 18th century, encroaching European expansionism in the area increased rice production in much of Southeast Asia, and Thailand, then known as Siam. British Burma became the world's largest exporter of rice, from the turn of the 20th century to the 1970s, when neighbouring Thailand exceeded Burma. In recent years, Vietnam has been a strong exporter, as well, occasionally eclipsing Thailand. While China, India, and Indonesia remain the top rice producers, they are also some of the top rice consumers.
Helitron (biology) Helitron (biology) Helitrons are one of the three groups of eukaryotic class 2 transposable elements (TEs) so far described. They are the eukaryotic rolling-circle transposable elements which are hypothesized to transpose by a rolling circle replication mechanism via a single-stranded DNA intermediate. They were first discovered in plants ("Arabidopsis thaliana" and "Oryza sativa") and in the nematode "Caenorhabditis elegans", and now they have been identified in a diverse range of species, from protists to mammals. Helitrons make up a substantial fraction of many genomes where non-autonomous elements frequently outnumber the putative autonomous partner. Helitrons seem to have a major role