Quark (dairy product) considered to be different types of fresh cheese, while in Eastern Europe cottage cheese is usually viewed as a type of quark (e.g. Russian for cottage cheese is "зернёный творог" "zernyony tvorog", literally "grainy quark"). Quark is similar to French fromage blanc, Indian paneer, and the queso fresco/queijo fresco made in the Iberian Peninsula and in some Latin American countries. It is distinct from Italian ricotta because ricotta (Italian "recooked") is made from scalded whey. Quark is somewhat similar to yogurt cheeses such as the South Asian "chak(k)a", the Arabic labneh, and the Central Asian suzma or kashk, but while
Quark routinely used in medical applications such as positron emission tomography (PET) and in experiments involving neutrino detection. While the process of flavor transformation is the same for all quarks, each quark has a preference to transform into the quark of its own generation. The relative tendencies of all flavor transformations are described by a mathematical table, called the Cabibbo–Kobayashi–Maskawa matrix (CKM matrix). Enforcing unitarity, the approximate magnitudes of the entries of the CKM matrix are: where "V" represents the tendency of a quark of flavor "i" to change into a quark of flavor "j" (or vice versa). There exists an