The functional role of the Xist transcript was first definitively demonstrated in mouse female ES cells using a novel antisense technology, called peptide nucleic acid (PNA) interference mapping.

It has also been associated with cases of serotonin syndrome, suggesting some interaction with serotonergic neurons, but the relationship has not been definitively demonstrated.

A strong correlation between radon anomalies and seismic events has not been demonstrated definitively.

But until now the ocean's heat absorption had not been definitively demonstrated, and its magnitude had not been determined.

What has been definitively demonstrated is that in most clinical situations, the patients who are transfused do considerably worse than those not transfused and those who get more transfusions almost always do worse than those getting fewer transfusions.

It is a claimed effect of low-carbohydrate diets and was popularised by the Atkins diet, but although several mechanisms exist to make it biologically plausible, it has yet to be definitively demonstrated as a significant factor in weight control.

This is most definitively demonstrated in Star Trek: Insurrection where Picard and Worf distract an erratically behaving Data by singing two parts of A British Tar, compelling Data to sing the third part.

Note: No study has definitively demonstrated improved outcome in critically ill patients managed with PA catheters.

Moreover, no such rise in population or decline in agricultural production has been definitively demonstrated.

This proposed classification has not been definitively demonstrated, largely because of slow progress in the reconstruction of the intermediate stages of the two language families involved, but is still considered promising by many linguists.