The ubiquity of plastics in oceans worldwide raises concerns about their ecological implications. Suspended microplastics (<5 mm) can be ingested by a wide range of marine organisms and may accumulate up the food web along with associated chemicals. Additionally, plastics provide a stable substrate to a wide range of organisms and, owing to their widespread dispersal, may function as vectors for harmful and invasive species. Despite the growing application of molecular techniques to study ocean microplastic colonizers, to date there is no comparative study on DNA extraction methods for ocean plastic biofilms. The present study aims to fill this gap by comparing DNA yield, amplification efficiency, costs and processing time of different DNA extraction techniques applied to oceanic microplastics. DNA was extracted with five methods (four extraction kits, and standard phenol:chloroform purification) using two mechanical lysis techniques (bead beating and cryogenic grinding with liquid nitrogen) applied to three plastic quantities (1, 15, and 50 fragments per extraction) and size classes (0.05-0.15 and 0.15-0.5 mm). All methods resulted in DNA suitable for downstream applications and were successfully amplified. Overall, the Qiagen Puregene Tissue kit yielded relatively high DNA concentrations for most sizes and amounts of plastics at relatively low costs and short processing time. This study provides a detailed evaluation of DNA extraction methods from ocean plastics, and may assist future research using molecular techniques to study ocean plastic biofilms.@en

The operational use of satellite systems has been increasing due to technological advances and the reduced costs of satellites and their launching. As such it has become more relevant to determine how to better use these new capabilities which is reflected in an increase in application studies in this area. This work focuses on the problem of developing the scheduling of a constellation of satellites and associated ground stations to monitor different types of locations (targets) with different priorities for a given planning horizon. In order to address this problem we will propose a new model that considers explicitly the operational requirements of Brazilian relevant scenarios for a given planning horizon and target priority list. The methodology to be developed to solve this model will also be discussed.@en