The small foreigner: new laws will promote the introduction of non-native zooplankton in Brazilian aquatic environments

Abstract Non-native species of zooplankton have been introduced in Brazilian continental aquatic environments for a variety of reasons (e.g., non-native fish stocking, aquaculture), but many pathways of zooplankton introductions remain unknown. Recently, the governor of the State of Amazonas passed Law No. 79/2016, which allows for aquaculture operations using non-native fish in that state. This change in policy will likely result in the species introduction or propagule pressure of non-native zooplankton such as: Mesocyclops ogunnus Onabamiro, 1957; Kellicottia bostoniensis (Rousselet, 1908); Daphnia lumholtzi Sars, 1885; Lernaea cyprinacea (Linnaeus, 1758); Lamproglena monodi Capart, 1944. Of further concern is federal law No. 5989/09, which proposes the use of non-native fish in Brazilian aquaculture nationwide. We believe that both laws will intensify the introduction of non-native zooplankton. Once established in aquatic environments, non-native species of zooplankton could result in negative impacts (e.g., a loss of ecosystem services, food web alterations). Therefore, Brazilian authorities should incentivize the use of local native species rather than pass laws that threaten the environment

Mimicking DNA stretching with the Static Mode method: Shear stress versus transverse pulling stress

International audienceDNA sequencing using nanopores is closer than ever to become a reality, but further research and development still need to be done, especially to unravel the atomic-scale mechanisms of induced DNA stretching. At this level, molecular modeling and simulation are essential to investigate DNA conformational flexibility and its response to the forces involved. In this work, through a “Static Mode” approach, we present a directed exploration of the deformations of a 27-mer subjected to externally imposed forces, as it could be in a nanopore. We show how the DNA sugar-phosphate backbone undergoes the majority of the induced deformation, before the base pairing is affected, and to what extent unzipping initiation depends on the force direction