The “implantation window” is a short, specific phase during which attachment of the blastocyst occurs.

At Tangshan, which is half a day by rail from Tangku, I was very kindly received by the engineer-in-chief of the railway and the mining companies and his wife.

Concordia diagrams are the most common way to present U-Pb data in the modern literature, so understanding them is key to understanding the method.

In Guerrero state, where about 40 armed groups including the CJNG operate, the police have been debilitated by outbreaks of coronavirus in its ranks, a senior Guerrero police official said.