1) The document discusses two studies: one on cassava starch settling processes in Colombia and another on sexual risk behaviors among Spanish adolescents based on age of sexual debut.
2) The cassava study evaluated sedimentation in channels used in small cassava starch industries, finding particles 6.7-8.8 μm were not retained and discharged into local waterways.
3) The sexual risk study analyzed protection methods among sexually experienced Spanish youth, finding those with debut before 15 engaged in more activities and with more partners, and used condoms less consistently, increasing infection risk.