The Japanese government said Thursday it will tighten border controls for visitors from Costa Rica, the Dominican Republic and Namibia in response to the spread of the highly contagious Delta variant of the novel coronavirus.In a new set of border control measures to take effect Sunday, visitors from the three countries as well as the Republic of Sakha in eastern Russia will be asked to stay in designated facilities for three days after arrival and be subject to more coronavirus testing, according to the Foreign Ministry.Travelers from Moscow will also be required to observe a six-day quara…READ FULL ARTICLE