Being born and growing up in the Ribeirão Preto and São Luís cohorts

This thematic issue consists of 14 articles derived from studies of the BRISA birth cohort (Ribeirão Preto, State of São Paulo and São Luís, State of Maranhão, northeastern Brazil, a socially and economically less developed region). In these more than 40 years of existence, these cohorts have been able to document the increase in women's education, the improvement of health conditions, the creation of a public Unified Health System (SUS) that provides universal and free access to health care, eradication of hunger, and transition of the nutritional status characterized by a decrease in malnutrition rates and an increase in obesity in Brazil. Particularly in reproductive health, the country experienced a significant drop in fertility, a decrease in maternal and child mortality, and an increase in breastfeeding rates. Universal access to prenatal care and hospital delivery was accompanied by an excessive number of cesareans without clinical indication and early-term births and premature births, largely due to scheduled cesareans. Articles with a longitudinal and transversal methodological approach are presented, using structural equation analysis and propensity score, together with multivariate regressions, which gave a robust analytical treatment to articles in this thematic issue.

Initiation and s uppression of sperm motility is osmolality dependent in two South American fish species: streaked prochilod (Prochilodus lineatus) and piracanjuba(Brycon orbignyanus)

Solutions to induce or suppress the initiation of sperm motility in fish ha ve been used to improve reproductive success during artificial fertilization and preservation techniques . The aim of the present study was to evaluate the effects of three solutions (NaCl, glucose , and BTS™) - each prepared with 10 different osmolalities - on the initiation and suppression of fresh sperm motility in Prochilodus lineat us and Brycon orbignyanus . Sperm was diluted in each of the 30 solution s and immediately observed under a light microscope to determine which solution s trigger ed or suppress ed the initiation of sperm motility. When present, motility rate ( % motile sperm ) w as determined at 0, 30 , and 120 s post - activation and the motility quality score ranging from 0 ( no movement ) to 5 ( rapidly swimming sperm) was determined at 0 and 30 s post - activation . Osmolality , but not solution composition , significantly affected both motility rate and quality score . Solutions at osmolali ties up to 270 mOsm/kg in P. lineatus and up to 180 mOsm/kg in B. orbignyanus induced motility in at least 60% of sperm , with a minimum quality score of 3.0 , and were therefore classified as activating agents. The greatest motility at 0 , 30 , and 120 s post - activation was observed with solutions ranging from 135 to 225 mOsm/kg for P. lineatus and at 135 mOsm/kg for B. orbignyanus . On the other hand, solutions ranging from 360 to 450 mOsm/kg in P. lineatus and 270 to 450 mOsm/kg in B. orbignyanus suppressed motility in at least 95% of sperm and were classified as immobilizing media . The osmolality of the surrounding medium is the key factor in the initiation or suppression of sperm motility in P. lineatus a nd B. orbignyanu.