Hayk Mirzayans Insect Museum offers training courses, and helps other scientific research centers in completion and maintenance of their insect collections. ITRD acts as the National Identification Service for governmental or non-governmental organizations, publishes various articles, reports, books, data banks and checklists of its holdings, and provides these information free of charge to all visitors. Hayk Mirzayans Insect Museum The Hayk Mirzayans Insect Museum (HMIM) is the largest insect collection in Iran with over 4 million insect specimens, including 20–25,000 local species, hundreds of primary types and paratypes, and a representative collection of exotic insects, especially tropical butterflies. In 1943, Iranian entomologist established a
Syntonic comma amount by which Didymus corrected the Pythagorean major third (81:64, around 407.82 cents) to a just major third (5:4, around 386.31 cents). The word "comma" came via Latin from Greek κόμμα, from earlier *κοπ-μα = "an act of cutting". The prime factors of the just interval 81/80 known as the syntonic comma can be separated out and reconstituted into various sequences of two or more intervals that arrive at the comma, such as 81/1 * 1/80 or (fully expanded and sorted by prime) 1/2 * 1/2 * 1/2 * 1/2 * 3/1 * 3/1 * 3/1 *3/1 * 1/5. All