Scarce swallowtail Republic have been found to be a good indicator of relatively well preserved xerothermic grassland habitats with forest-steppe vegetation, which have no cutting history. In some years the scarce swallowtail is quite abundant. The scarce swallowtail is getting rarer as the blackthorn bushes are being cleared. The butterfly is now protected by law in the Czech Republic, Slovakia, Germany, Hungary, Luxembourg, Russia, Ukraine and Poland. It is considered rare and endangered and protected in some provinces of Austria and of indeterminate status throughout Europe. In Armenia the species demonstrates stable population trend and is evaluated as Least Concern. Though referred
Holdrian comma Holdrian comma In music theory and musical tuning the Holdrian comma, also called Holder's comma, and sometimes the Arabian comma, is a small musical interval of approximately 22.6415 cents, equal to one step of 53 equal temperament, or formula_1 (). The name comma is misleading, since this interval is an irrational number and does not describe the compromise between intervals of any tuning system; it assumes this name because it is an approximation of the syntonic comma (21.51 cents)(), which was widely used as a measurement of tuning in William Holder's time. The origin of Holder's comma resides in the