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First Record on Sex Chromosomes in a Species of the Family Cynodontidae: Cynodon gibbus (Agassiz, 1829)
No full textThe fish family Cynodontidae belongs to the superfamily Curimatoidea, together with the Hemiodontidae, Serrasalmidae, Parodontidae, Prochilodontidae, Chilodontidae, Curimatidae, and Anostomidae. The majority of the species of this superfamily that have been analyzed to date have a diploid chromosome number of 2n = 54. Differentiated sex chromosomes (with female heterogamety) have been observed only in the Prochilodontidae, Parodontidae, and Anostomidae. The present study provides the first description of differentiated sex chromosomes in the cynodontid species Cynodon gibbus, which has a ZZ/ZW system, and shows that repetitive DNA has played a fundamental role in the differentiation of these sex chromosomes. © 2020 S. Karger AG, Basel
Deforestation dynamics in Brazil's Amazonian settlements: Effects of land-tenure concentration
No full textBeyond diversity loss and climate change: Impacts of Amazon deforestation on infectious diseases and public health
Full text linkGEEA - Caderno de Debates: TOMO XVI
No full textO Tomo XVI trata de dois temas emblemáticos: a pesca e a fome. Quanto ao primeiro, são feitas considerações sobre a situação da pesca na Amazônia, mesmo a despeito da fragmentação dos dados de desembarque disponíveis; é traçado um paralelo entre a produção mundial e brasileira nos últimos anos, com enfoque sobre a produção na Amazônia brasileira, em especial no Estado do Amazonas; são consideradas as distintas modalidades da pesca, as espécies exploradas, a situação dos estoques pesqueiros, o manejo e o ordenamento do setor pesqueiro. Quanto à fome, são tratadas questões relativas à produção de alimentos, superpopulação humana, preservação do meio ambiente, custos do desenvolvimento sustentável, desperdício, segurança alimentar, papel da agricultura e da Amazônia nesse contexto. As questões vinculadas à pesca e à fome estão conectadas entre si e também com a educação, a saúde, a cultura, a política e o meio ambiente e por isso devem ser sempre tratadas em conjunto, como aqui foi feito. Que seja uma leitura enriquecedora para todos
The impact of low and high pH on in vitro heart metabolism of the Amazonian armored catfish Pterygoplichthys pardalis
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Two new species of Hydraena Kugelann, 1794 from Brazil (Coleoptera: Hydraenidae)
No full textHydraena (Hydraenopsis) josefinae sp. nov. and H. (H.) pernambucana sp. nov. are described respectively from Amapá and Pernambuco States, Brazil. Hydraena (H.) josefinae sp. nov. is a member of the scintillabella subgroup of the leechi group, while H. (H.) pernambucana sp. nov. belongs to the orcula complex in the marginicollis subgroup of the marginicollis group. Descriptions and diagnostic characters for both new species are offered; habitus photographs and line drawings of male genitalia of the two new species, as well as drawings of female genitalia of H. josefinae sp. n., are provided. Male genitalia of H. alterra Perkins, 1980 is illustrated and compared with that of the closely related H. josefinae sp. nov. Habitat and distributional data of the two new species are also included. Copyright © 2020 Magnolia Press
Evolutionary history of Neotropical savannas geographically concentrates species, phylogenetic and functional diversity of lizards
No full textAim: Understanding where and why species diversity is geographically concentrated remains a challenge in biogeography and macroevolution. This is true for the Cerrado, the most biodiverse tropical savanna in the world, which has experienced profound biodiversity loss. Previous studies have focused on a single metric (species composition), neglecting the fact that ‘species’ within the biome are often composed of cryptic species. In order to identify biodiversity hotspots more robustly and across multiple dimensions we integrate functional, spatial and new phylogeographic data for the Cerrado lizard fauna by (a) mapping the spatial patterns of species and phylogenetic diversity; and (b) using endemism measures to identify areas of unique diversity. We then quantify the extent to which existing protected areas represent the diversity. Location: Brazilian savanna (Cerrado). Methods: We generated species distribution models using distribution records for all Cerrado lizard species. These, combined with mitochondrial DNA phylogenies and natural history data, allowed us to map species richness, phylogenetic and functional diversity and phylogenetic and weighted endemism. Phylogenetic endemism maps were then cross-referenced against protected areas to calculate the amount of evolutionary history preserved within these areas. Results: The central region of the Cerrado, a vast and climatically stable plateau, stands out as important under all biodiversity metrics. Including evolutionary relationships in biodiversity assessment, we detected four regional hotspots with high concentration of spatially restricted evolutionary diversity. Protected areas cover only 10% of the Cerrado area and hold 11.64% of the summed phylogenetic endemism of all lizards in the biome. Main Conclusions: We highlighted both stable (Chapada dos Veadeiros and Serra do Espinhaço plateaus) and environmentally heterogenous regions (Araguaia and Tocantins valleys) as hotspots of evolutionary diversity. The creation and/or manipulation of areas for conservation are essential for the conservation and survival of the rich and endemic lizard fauna of the Cerrado. © 2020 John Wiley & Sons Lt
Synthesis, molecular docking studies, and larvicidal activity evaluation of new fluorinated neonicotinoids against Anopheles darlingi larvae
Full text linkAnopheles darlingi is the main vector of malaria in Brazil, characterized by a high level of anthropophilia and endophagy. Imidacloprid, thiacloprid, and acetamiprid are the most widespread insecticides of the neonicotinoid group. However, they produce adverse effects on the non-target insects. Flupyradifurone has been marketed as an alternative to non-fluorinated neonicotinoids. Neonicotinoids containing trifluoroacethyl substituent reveal increased insecticidal activity due to higher hydrophobicity and metabolic stability. We synthesized novel neonicotinoid insecticides containing fluorinated acceptor groups and their interactions were estimated with the nicotinic acetylcholine receptor (nAChR) binding site by molecular docking studies, to evaluate their larvicidal activity against A. darlingi, and to assess their outdoor photodegradation behavior. New neonicotinoid analogues were prepared and characterized by NMR and mass-spectrometry. The synthesized molecules were modelled by time-dependent density functional theory and analyzed, their interaction with nAChR was investigated by molecular docking. Their insecticide activity was tested on Anopheles larvae collected in suburban area of Manaus, Brazil. Four new fluorinated neonicotinoid analogs were prepared and tested against 3rd instars larvae of A. darlingi showing high larvicidal activity. Docking studies reveal binding modes of the synthesized compounds and suggest that their insecticidal potency is governed by specific interactions with the receptor binding site and enhanced lipophilicity. 2-Chloro-5-(2-trifluoromethyl-pyrrolidin-1-ylmethyl)pyridine 5 showed fast degradation in water maintaining high larvicidal activity. All obtained substances possessed high larvicidal activity in low concentrations in 48 hours of exposure, compared to commercial flupyradifurone. Such activity is connected to a unique binding pattern of the synthesized compounds to insect's nAChR and to their enhanced bioavailability owing to introduction of fluorinated amino-moieties. Therefore, the compounds in question have a high potential for application as control agents for insects transmitting tropical diseases, and they will be less persistent in the environment. © 2020 da Silva Mesquita et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited
