After comparing the performance of a maquiladora-using firm with that of a controlsample, the authors found no evidence of net gain in the use of a maquiladora.
If existing studies are too weak to support the use of breast screening, then the chances of organising large-scale replacements are slim, as these would have to involve a sizeable "control" sample who would not be screened for the purposes of comparison.
Only when Centers for Disease Control and Prevention scientists sent a suspect sample to the mass spectrometer did they discover the new variety of swine flu, according to an article describing the techniques in Science magazine.
The panel also noted that the "evidence suggesting very clearly that the analyitcal results reported by DCC (Drug Control Centre, Kings College London) in connection with the A sample were difficult to interpret".