BACKGROUND The clinical value of free thyroxine (FT(4)) and free triiodothyronine (FT(3)) analysis depends on the reference intervals with which they are compared. We determined age- and sex-specific reference intervals for neonates, infants, and children 0-18 years of age for FT(4) and FT(3) using tandem mass spectrometry. METHODS Reference intervals were calculated for serum FT(4) (n = 1426...

The system FT of ordering constraints over feature trees has been introduced as an extension of the system FT of equality constraints over feature trees. We investigate decidability and complexity questions for fragments of the first-order theory of FT . It is well-known that the first-order theory of FT is decidable and that several of its fragments can be decided in quasi-linear time, includi...

The developmental transition from a vegetative to a reproductive phase (i.e., flowering) is timed by the seasonal cue day length or photoperiod in many plant species. Through the photoperiod pathway, inductive day lengths trigger the production of a systemic flowering signal, florigen, to provoke the floral transition. FLOWERING LOCUS T (FT), widely conserved in angiosperms, is a major componen...

This paper presents the constraint system FT, which we feel is an intriguing alternative to Herbrand both theoretically and practically. As does Herbrand, FT provides a universal data structure based on trees. However, the trees of FT (called feature trees) are more general than the trees of Herbrand (called constructor trees), and the constraints of FT are ner grained and of diierent expressiv...

The Fair Trade (FT) initiative has been hugely popular with coffee consumers around the world, and yet the creation of durable producer rents is challenging in a competitive market environment. We model the FT premium actually received by producers and suggest that rents are in fact dissipated, but that this occurs in ways that are quite obscure to consumers. First, over-certification dilutes t...