Comment—Cross-Brand Pass-Through: Fact or Artifact?

Transdifferentiation--fact or artifact.

Normal development appears to involve a progressive restriction in developmental potential. However, recent evidence suggests that this progressive restriction is not irreversible and can be altered to reveal novel phenotypic potentials of stem, progenitor, and even differentiated cells. While some of these results can be explained by the presence of contaminating cell populations, persistence ...

Psychiatric comorbidity: fact or artifact?

The frequent occurrence of comorbidity has brought about an extensive theoretical debate in psychiatry. Why are the rates of psychiatric comorbidity so high and what are their implications for the ontological and epistemological status of comorbid psychiatric diseases? Current explanations focus either on classification choices or on causal ties between disorders. Based on empirical and philoso...

Menstrual synchrony: Fact or artifact?

Although more than thirty years of intensive investigation have passed since McClintock first published results on menstrual synchrony, there is still no conclusive evidence for the existence of this phenomenon. Indeed, a growing body of nullresult studies, critiques of menstrual synchrony studies, and the lack of convincing evolutionary explanations bring into question the existence of this ph...

Functional connectivity MR imaging: fact or artifact?

Adult stem cell plasticity: fact or artifact?

There has been unprecedented recent interest in stem cells, mainly because of the hope they offer for cell therapy. Adult stem cells are an attractive source of cells for therapy, especially in view of the recent claims that they are remarkably plastic in their developmental potential when exposed to new environments. Some of these claims have been either difficult to reproduce or shown to be m...