The National Diet Library (NDL) (国立国会図書館, Kokuritsu Kokkai Toshokan) is the only national library in Japan. It was established in 1948 for the purpose of assisting members of the National Diet of Japan (国会, Kokkai) in researching matters of public policy. The library is similar in purpose and scope to the United States Library of Congress.
The National Diet Library (NDL) consists of two main facilities in Tokyo and Kyoto, and several other branch libraries throughout Japan.
The National Diet Library is the successor of three separate libraries: the library of the House of Peers, the library of the House of Representatives, both of which were established at the creation of Japan's Imperial Diet in 1890; and the Imperial Library, which had been established in 1872 under the jurisdiction of the Ministry of Education.
The Diet's power in prewar Japan was limited, and its need for information was "correspondingly small." The original Diet libraries "never developed either the collections or the services which might have made them vital adjuncts of genuinely responsible legislative activity." Until Japan's defeat, moreover, the executive had controlled all political documents, depriving the people and the Diet of access to vital information. The U.S. occupation forces under General Douglas MacArthur deemed reform of the Diet library system to be an important part of the democratization of Japan after its defeat in World War II.
Delta endotoxins (δ-endotoxins, also called Cry and Cyt toxins) are pore-forming toxins produced by Bacillus thuringiensis species of bacteria. They are useful for their insecticidal action.
During spore formation the bacteria produce crystals of this protein. When an insect ingests these proteins, they are activated by proteolytic cleavage. The N-terminus is cleaved in all of the proteins and a C-terminal extension is cleaved in some members. Once activated, the endotoxin binds to the gut epithelium and causes cell lysis by the formation of cation-selective channels, which leads to death. The activated region of the delta toxin is composed of three distinct structural domains: an N-terminal helical bundle domain (IPR005639) involved in membrane insertion and pore formation; a beta-sheet central domain involved in receptor binding; and a C-terminal beta-sandwich domain (IPR005638) that interacts with the N-terminal domain to form a channel.