It would take at least a decade to meet the administration's criteria, and that is a conservative estimate, Mr. Tucker said.
The Obama administration's criteria for favorable treatment seem narrow and unlikely to cause much political trouble for the president.
Dr. Brent E. Wallace, chief medical officer at Intermountain Healthcare, in Utah, said the administration's criteria were "too rigid, requiring too much change in too short a time".
The critics complained, for example, that the administration diluted criteria that would be used to evaluate the performance of abstinence-only education programs so as to obscure their lack of efficacy.
The C.I.A. worried that Mr. Mehsud, whose group then mainly targeted the Pakistan government, did not meet the Obama administration's criteria for targeted killing: he was not an imminent threat to the United States.
Beyond that, the administration listed criteria for the approval of a drone strike: "Near certainty" the target was present and that civilians would not be injured or killed.
Despite diversity in number, clinical status of subjects, route of cell administration, and criteria to evaluate efficacy, the main conclusion drawn from these clinical studies was that such therapies were safe.
As such these studies underscore the importance of factors such as treatment duration, bioavailability, route of administration, selection criteria, standardized formulation and clinical end points in clinical trial design with both entities.
In a statement, Mayor Diaz called it "an important step toward creating the green jobs of the future and building a clean energy economy" and noted that it should meet the Obama administration's criteria for a "shovel ready" project that is eligible for stimulus funds.
The total number of prisoners who met the administration's criteria for clemency is believed to be around 1,500.
