The phrase "a second strand of" is correct and usable in written English.
It can be used to refer to an additional or alternative aspect of a topic or argument, often in discussions or analyses.
Example: "In addition to the primary argument, there is a second strand of thought that emphasizes the importance of emotional intelligence in leadership."
Alternatives: "an additional aspect of" or "a different dimension of".
Science fiction is full of robots-usurping-humans stories, sometimes entwined with a second strand of anxiety: seduction.
A second strand of opposition comes from what I think of as the Bah Humbug caucus: fiscal scolds who routinely issue sententious warnings about rising debt.
He also faces no further action over a second strand of the police investigation, into suspected conspiracy to pervert the course of justice and perjury in relation to the outing of Nightjack.
Pakistan could also leverage its presence in the peace process through its close ally Saudi Arabia, which recently offered to host a second strand of the peace talks in its capital, Riyadh.
French prosecutors are believed to be pursuing a twin-track approach: pursuing those they believe to have been involved specifically in the IAAF corruption while also considering a host of wider, related issues as part of a second strand of inquiry.
Leslie Orgel and his associates at the Salk Institute demonstrated in the 1980s that chemically activated nucleotide monomers line up on synthetic RNA templates by Watson-Crick base pairing, as they do in the double helix of DNA, and then polymerize into a second strand of RNA.
An enzyme called DNA polymerase then builds a second strand on each of the two single strands, by stringing together the proper chemical units of DNA.
Egypt should be a third strand of the U.S. policy of backing moderation and reconciliation.
A third strand of the paper, a writing paper also marked internally, showed that 45 per cent got a top-grade pass.
This provided a third strand of his past that can be seen to have had a direct bearing on his books.
And in a third strand of attack, campaigners at Warwick University said BP was continuing to resist opening its corporate archive based on the student campus.
