The phrase "a complex matter in" is correct and usable in written English.
It can be used when discussing a topic or issue that involves multiple factors or is difficult to understand, often in academic or formal contexts.
Example: "The negotiations surrounding the treaty were a complex matter in international relations."
Alternatives: "a complicated issue in" or "a challenging topic in".
"We do understand that it is politically a complex matter in Japan," he said after meeting Defense Minister Toshimi Kitazawa.
The process of ageing is a complex matter in which many different genes appear to be involved, but in time it may become possible to use gene therapy to slow down ageing, if not eliminate it.Accidents will happenNot that, even if ageing could be stopped altogether, people would stop dying.
Richard Gilman, a literary and theater critic who died in 2006, came as close to anyone in defining it: Being a sports fan is a complex matter, in part irrational but not unworthy, a relief from the seriousness of the real world, with its unending pressures and often grave obligations..
However, negotiating the balance between the reality of their circumstances and directives about the responsibilities ensuing from a positive status, turned out to be a complex matter in practice.
Oncogene-induced ROS have been a complex matter in the literature and so far what has been established is limited to ROS scavenging reduces DDR and eventually commitment to cellular senescence.
What caused the diseases that led them to cluster in the first place is a complex matter, rooted in history, exacerbated by humiliations and suspicions, inflamed by superstition, and made murderous by the availability of guns and bombs.
For anyone committed to the ideal of a multicultural society, the murder of cartoonists who vulgarly ridiculed Islamic faith proves a complex matter to address in times of soaring Islamophobia.
"It was always an extremely complex matter in which a different interpretation of a judgment made under Italian law could lead to an entirely different outcome in the context of our regulations.
And since museum visiting can be such a complex matter (of personal feelings in public places, ecstasy and boredom, ambitions and memories, incommunicable revelations, tastes in common and at odds), it's a joy to read words that are so consummately up to the job.
As different scripts serve different functions and make different demands upon readers, it is a complex matter to define literacy in universal terms and so to judge the literacy levels of a society at different periods or to compare one society with another.
Ranking is also a complex matter that I discuss in more detail there [ 69].
