Oxytocin is a nonapeptide involved in a wide range of physiologic and behavioral functions. Until recently, it was believed that an unmodified oxytocin sequence was present in all placental mammals. This study analyzed oxytocin (OXT) in 29 primate species and the oxytocin receptor (OXTR) in 21 of these species. We report here three novel OXT forms in the New World monkeys, as well as a more extensive distribution of a previously described variant (Leu8Pro). In structural terms, these OXTs share the same three low-energy conformations in solution during molecular dynamic simulations, with subtle differences in their side chains. A consistent signal of positive selection was detected in the Cebidae family, and OXT position 8 showed a statistically significant (P = 0.013) correlation with litter size. Several OXTR changes were identified, some of them promoting gain or loss of putative phosphorylation sites, with possible consequences for receptor internalization and desensitization. OXTR amino acid sites are under positive selection, and intramolecular and intermolecular coevolutionary processes with OXT were also detected. We suggest that some New World monkey OXT-OXTR forms can be correlated to male parental care through the increase of cross-reactivity with its correlated vasopressin system.OXT | OXTR | primates | coevolution | behavior

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We study the dynamics of transverse oscillations near the linear coupling resonance excited by a pair of skew quadrupoles at the Laboratório Nacional de Luz Síncrotron UVX electron storage ring through the analysis of the beam profile. Transverse coherent oscillations were excited with a fast kicker and the profile of the oscillating beam was observed by focusing visible synchrotron radiation from a bending magnet onto a fast charge-coupled device camera. Using a single resonance approximation, we calculated the border of the time-averaged transverse beam profile as a function of the complex coupling coefficient k, which characterizes the distribution of coupling fields along the storage ring. A leastsquares fit of the calculated beam profile border to the experimentally obtained isointensity contours provided a new method to determine both the modulus and the phase of k. The values obtained for the modulus are in good agreement with those from the conventional normal mode tune separation technique, and the values obtained for the phase of k agree with calculations based on the model lattice and the known skew quadrupole distribution. [S1098-4402(98)

We present initial results of the optics calibration project of the LNLS UVX electron storage ring by the use of the response matrix formalism.