BUSCADOR RECOLECTA

Collisions are the chief effect of transport infrastructures on vertebrate populations but their relevance in high-speed railways (HSR) is largely unknown. We analyzed Great Bustard (Otis tarda) and Eurasian Eagle-owl (Bubo bubo) mortality along two 5-km stretches of a Spanish HSR. Five fresh bustard and 10 owl carcasses were collected during 40 weeks of monitoring over two years, plus older remains of 14 bustards and 17 owls more. Relevant mortalities of both bird species thus occur, and differences in local use of the infrastructure explain their spatial patterns. Bustards die at points where they fly across optimizing their local movements according to MaxEnt models, while owls die while hunting the abundant rabbits present in railway verges as pointed by camera trapping. Impact prediction, evaluation and mitigation must therefore accommodate to species’ characteristics.

Background: Pappalysins (PAPP-A, PAPP-A2) modulate body growth by increasing IGF-I bioavailability through cleavage of IGFBPs and are inhibited by stanniocalcins (STC1, STC2). Normative data of these novel factors, as well as of free IGF-I and uncleaved fractions of IGFBPs are not well established.

Objective: To determine serum concentrations of PAPP-A, PAPP-A2, STC1 and STC2, in relationship with other GH-IGF axis parameters during development.

Patients and methods: Full-term newborns (150; gestational age: 39.30 ± 1.10 weeks), 40 preterm newborns (30.87 ± 3.35 weeks) and 1071 healthy individuals (1-30 years old) were included in the study and divided according to their Tanner stages (males and females): I:163 males, 154 females; II:100 males, 75 females; III:83 males, 96 females; IV: 77 males, 86 females; and V:109 males,128 females.

Results: Serum concentrations of total and free IGF-I, IGF-II, total IGFBP-3 and ALS rose gradually during development peaking in Tanner stages III-IV. Concentrations of IGFBP-4 and IGFBP-5 were lower in prepubertal children. PAPP-A, PAPP-A2, STC1, STC2, IGFBP-2, total IGFBP-4 and total IGFBP-5 were elevated at birth and declined throughout childhood. In postnatal life, PAPP-A2 concentrations decreased progressively in concomitance with the free/total IGF-I ratio; however, stanniocalcin concentrations remained stable. PAPP-A2 concentrations positively correlated with the free/total IGF-I ratio (r=+0.28 p<0.001) and negatively with the intact/total IGFBP-3 ratio (r=-0.23, p<0.001). PAPP-A concentrations inversely correlated with intact/total IGFBP-4 ratio (r=-0.21, p<0.001), with PAPP-A concentrations being lower in females at all ages.

Conclusion: This study provides reference values of pappalysins and stanniocalcins, which modulate IGF-I activity by changing the concentrations of uncleaved IGFBPs.