Preface: “Quarks-2016”, 19th International Seminar on High Energy PhysicsVladimir Andrianov, Victor Matveev, Valery Rubakov, Alexander Andrianov, Maxim Fitkevich, Ivan Kharuk, Victor Kim and Sergei KolevatovEPJ Web Conf., 125 (2016) 00001DOI: https://doi.org/10.1051/epjconf/201612500001