Multi-detection method for five common microalgal toxins based on the use of microspheres coupled to a flow-cytometry system

Freshwater and brackish microalgal toxins, such as microcystins, cylindrospermopsins, paralytic toxins, anatoxins or other neurotoxins are produced during the overgrowth of certain phytoplankton and benthic cyanobacteria, which includes either prokaryotic or eukaryotic microalgae. Although, further studies are necessary to define the biological role of these toxins, at least some of them are known to be poisonous to humans and wildlife due to their occurrence in these aquatic systems. The World Health Organization (WHO) has established as provisional recommended limit 1 μg of microcystin-LR per liter of drinking water. In this work we present a microsphere-based multi-detection method for five classes of freshwater and brackish toxins: microcystin-LR (MC-LR), cylindrospermopsin (CYN), anatoxin-a (ANA-a), saxitoxin (STX) and domoic acid (DA). Five inhibition assays were developed using different binding proteins and microsphere classes coupled to a flow-cytometry Luminex system. Then, assays were combined in one method for the simultaneous detection of the toxins. The IC₅₀'s using this method were 1.9 ± 0.1 μg L⁻¹ MC-LR, 1.3 ± 0.1 μg L⁻¹ CYN, 61 ± 4 μg L⁻¹ ANA-a, 5.4 ± 0.4 μg L⁻¹ STX and 4.9 ± 0.9 μg L⁻¹ DA. Lyophilized cyanobacterial culture samples were extracted using a simple procedure and analyzed by the Luminex method and by UPLC–IT-TOF-MS. Similar quantification was obtained by both methods for all toxins except for ANA-a, whereby the estimated content was lower when using UPLC–IT-TOF-MS. Therefore, this newly developed multiplexed detection method provides a rapid, simple, semi-quantitative screening tool for the simultaneous detection of five environmentally important freshwater and brackish toxins, in buffer and cyanobacterial extracts.

Som da Maré: Um Projeto Participativo de Arte Sonora

In May 2014, the participative Project Som da Maré brings together the creative energy of a group of inhabitants from a cluster of favelas in Maré (Rio de Janeiro)* through the sonic arts. The work recalls everyday experiences, memories, stories and places. These memories elicit narratives that leave traces in space while contributing to the workings of local cultural.

The result of four months of workshops and fieldwork forms the basis of two cultural interventions: an exhibition in Museu da Maré** and guided soundwalks in the city of Rio de Janeiro. These interventions present realities, histories and ambitions of everyday life in the Maré favelas through immersive sound installation, documentary photography, text and objects.

Som da Maré brings together various groups of participants who together have developed themes, materials and strategies for the articulation of elements of everyday life in Maré. Participants include secondary level students under the Fundação de Amparo à Pesquisa do Estado do Rio de Janeiro (FAPERJ) “Young Talent” scholarships and their families, post-graduate students at the Universidade Federal do Rio de Janeiro (UFRJ), PhD students from the Sonic Arts Research Centre (Queen’s University Belfast) and members of the Cia Marginal, a theatre company based in Maré. The project also counts with the participation of academics from music, ethnomusicology, visual art and architecture at the UFRJ and a partnership with the Museu da Maré. Over thirty people have come together to make this project possible.