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Reseña de Quillahuaman, Rocío. Marrón. Memorias. Blackie Books, 2022, 200 pp

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This essay aims to collaborate with the discussion of racial identities within the field of psychology and affirmative action policies. To this end, we made a brief historical-conceptual discussion on Brazilian racial classifications, racial identity formations, as well as racial identifications, because, through these concepts, we intend to think of the pardo's standpoint in the constitution of phenotypically black and white 'mestizo' subjects. We have established this discussion for two main reasons. The first reason refers to the fact that, in Brazil, the pardo represents a complex racial identity, often perceived as confusing, diffuse, both denied and affirmed. This theme relates to one of the most iconic dimensions of Brazilian racism, especially since within this group there are variations between the pardo with notably white features and the pardo phenotypically read as black. The second and foremost reason concerns the fact that this theme is keystone in order to understand the manner in which this intermediate standpoint connects to the affirmative action policies debate in the contemporary Brazilian social context. [ABSTRACT FROM AUTHOR]

Zeolite is known to uptake toxic metals and filter nitrogenous waste from aquaculture effluents. The present study aimed to investigate the impacts of zeolite in three different applications namely, dietary zeolite (DZ), suspended zeolite (SZ) in the water column, and a combination of both (DZSZ) relative to unexposed freshwater crayfish, marron (control). At the end of the 56-days trial, the impact was assessed in terms of characterization of microbial communities in the culture environment and the intestine of marron. Alongside the microbial communities, the innate immune response of marron was also evaluated. The 16S rRNA data showed that marrons exposed to the suspended zeolite had a significant increase of bacterial diversity in the gut, including the restoration of marron core operational taxonomic units (OTUs), relative to other forms of exposures (DZ, DZSZ) and the control. Suspended zeolite alone also increased the number of unshared OTUs and genera, and improved predicted metabolic functions for the biosynthesis and digestion of proteins, amino acids, fatty acids, and hormones. In the tank sediment, the shift of microbial communities was connected more strongly with the time of experiment than the type of zeolite exposure. In the second case, only control marron had a different microbial ordination in terms of rare taxa present in the community. Nevertheless, the modulation in the gut environment was found more prominent in DZ, relative to modulation in the tank sediments. The taxa-environment correlation identified Rhodoferax as the most potential bacteria in removing nitrogenous waste from the rearing environment. Further analysis showed that SZ resulted in the upregulation of genes associated with the innate immune response of marron. Overall results suggest that SZ can be used to enrich microbial communities in the gut and tank sediments and better immune performance of marron. [Display omitted] • The efficacy of zeolite was tested on water quality, C/N ratio, and microbiota in the sediment and crayfish gut. • Suspended zeolite showed higher C/N retention ability over time. • Suspended zeolite improved gut microbial diversity, metabolic functions, and immune response. • Rhodoferax spp., was found positively correlated to nitrogen waste removal. • Zeolite in suspended form can be used for crayfish aquaculture. [ABSTRACT FROM AUTHOR]