The phrase "subject of efforts" is correct and usable in written English.
You can use it when referring to something that requires effort. For example: "The environment has become a subject of considerable efforts from environmentalists around the world."
Jones, in trying to avoid the subject of effort, may have said more than he intended.
Two of the senators who were the subjects of efforts of the mayors' group, Kay Hagan of North Carolina and Joe Donnelly of Indiana are now signaling their support for expanded background checks.
THE AIDS epidemic has been the subject of countless efforts at exploration and explanation in all manner of media, from popular films like "Philadelphia," to Pulitzer Prize-winning dramas like "Angels in America," to television tear-jerkers like "The Ryan White Story".
Republicans said that they had also helped with petitions for protest candidates in Democratic primaries for lieutenant governor and for all four of the State Senate seats that are the subject of recall efforts.
NHS sources say Stevens – a former NHS graduate trainee – has been the subject of sustained efforts over recent weeks to persuade him to take the job because, with an American wife and children, he was initially reluctant to return home from the US, where he is the president of United Healths global health division.
Due to the increasing industrial use of titanium compounds, its determination is the subject of considerable efforts.
However, developing and engineering of the corresponding nanostructures with reproducible architecture and preassigned optical properties is a subject of continuous efforts [15, 16].
Automatic vehicle driving has long been the subject of research efforts designed to improve the safety and efficiency of automobile transportation.
Non-opaque objects have received less attention, although various special cases have been the subject of research efforts, especially the case of specular objects.
We now have clear evidence of what we knew all along, that there are perhaps thousands of scientists who don't share these views, and sadly have been the subject of concerted efforts to discourage and suppress their findings from publication".
