Glutathione S-transferase (GST) is one of the enzymes used to evaluate the effects caused by environmental contaminants. The aim of this work was to study the effects of four pyrethroid compounds (allethrin, cypermethrin, deltamethrin and fenpropathrin) on the catalytic activity of GST and to estimate the potential for environmental contamination in silico of these insecticides. Spectrophotometric analyses showed that the activity of the GST enzyme was inhibited by the four pesticides, with the values for the inhibition constant (Ki) varying from 0.12 to 20 µmol L-1, with the following order of inhibition from the highest to the lowest Ki value: deltamethrin > cypermethrin > allethrin > fenpropathrin. They presented a competitive and non-competitive inhibition mechanism depending on the compound. The IC50 values (concentration that inhibits 50% of the enzyme activity) showed the insecticide deltamethrin with greater inhibitory capacity, since it reduced the activity of the GST enzyme by half, even though it was in a lower concentration in relation to the other analyzed compounds. The in silico evaluation indicated the possibility of most of the insecticides contaminating the surface waters (rivers and lakes) adhered to the suspended sediment, but did not show any potential for contamination of groundwater through leaching.

Abstract Differences in species composition between sites (β diversity) may be the result of spatial species replacement (turnover) or nestedness (subgroups of species from a more diverse site). In fragmented landscapes, the environmental factors that lead to these differences may be spatially structured. Herein, our objective is to determine if the β diversity of Chrysomelidae (Coleoptera) is due to turnover or nestedness and whether the observed pattern is due to loss of forest cover or spatial processes in forest remnants immersed in a matrix dominated by intense agricultural practice. We used an incidence matrix of 99 species sampled from 16 forest remnants and found that the difference in species composition among the fragments is mostly determined by turnover and that this variation is not explained by forest cover or spatial variables. In regions where high habitat loss has generated landscapes containing small and islated forest fragments, structural features, related both to habitat (area, isolation, shape, etc.) and landscape (land use, landscape heterogeneity, etc.) could predict diversity patterns.

Natural sources with high antioxidant capacity represent an interesting potential to prevent or minimize the oxidative stress that causes many chronic diseases. The antioxidant capacity of red fruits (strawberry and cherry) was evaluated by miniaturized spectrophotometric methods 2,2’-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS), 2,2-diphenyl-1-picrylhydrazyl (DPPH) and nitroblue tetrazolium (NBT). ABTS and DPPH colorimetric methods are based on the ability of antioxidants to scavenge synthetic free radicals produced in vitro, which have a different chemical structure from the natural reactive oxygen species generated in the human body. In this respect, the NBT method stands up because it is based on O2•– scavenging which is generated in vitro by enzymatic reaction systems. The spectrophotometric assays adapted on microtiter plates allowed a rapid, inexpensive and simultaneous analysis. Larger amounts of lipophilic and hydrophilic antioxidants were obtained from strawberry fruit, which showed the lowest 50% signal inhibition concentration (IC50) values. The fruit analyzed showed promising sources of bioactive compounds with high antioxidant properties.

RESUMO A área de uma mancha de habitat pode aumentar a riqueza local de espécies tanto diretamente (pelo balanço entre imigração e extinção) quanto indiretamente (por aumentar a heterogeneidade do habitat e/ou como efeito do esforço amostral). Ambientes mais heterogêneos apresentam maior variedade de recursos e condições permitindo a coexistência de espécies por diferenciação de nicho. Neste estudo mostramos que a riqueza de Chrysomelidae depende da área e da estrutura do habitat em remanescentes de floresta semidecidual. Realizamos amostragens com armadilhas Malaise em 16 remanescentes florestais entre agosto de 2012 e março de 2013. Para caracterizar o habitat, medimos a área, a heterogeneidade estrutural do sub-bosque, a cobertura e a altura do dossel. Estas variáveis foram utilizadas em uma análise de caminhos para determinar seus efeitos diretos e indiretos na riqueza de crisomelídeos. Capturamos 450 espécimes de 99 espécies e cinco subfamílias. A área total e a heterogeneidade do sub-bosque apresentaram um efeito positivo sobre a riqueza de espécies, enquanto a cobertura do dossel exerceu efeito direto negativo. A altura do dossel apresentou apenas efeito indireto e negativo sobre a riqueza de crisomelídeos. Em fragmentos com maior área e mais espaços abertos, provavelmente a abundância e a riqueza de plantas tendem a serem maiores, favorecendo a coexistência de muitas espécies de Chrysomelidae.

ABSTRACT The total area of a habitat patch can increase the local species richness both directly (through balance between immigration and extinction) and indirectly (by increasing the habitat heterogeneity and/or as an effect of sample effort). More heterogeneous environments present a wider variety of resources and conditions, allowing species to coexist through niche differentiation. This study shows that the diversity of Chrysomelidae depends on the area and habitat structure of semideciduous forest remnants. We sampled 16 remnants with Malaise traps in August 2012 to March 2013. In order to characterize the habitat, the area, structural heterogeneity of the understory, coverage and canopy height were measured. These variables were used in a path analysis to determine their direct and indirect effects on leaf beetle diversity. A total of 450 specimens from 99 species and five subfamilies were captured. The total area and the understory heterogeneity presented a positive effect on species richness, while canopy cover exerted a negative one. The canopy height only had a negative and indirect effect on leaf beetle richness. In such fragments with more area and more open spaces, plant abundance and richness tend to be higher and favor the coexistence of many Chrysomelidae species.

RESUMO As informações de distribuição das espécies de aves em diferentes habitats e a estrutura de suas comunidades são cruciais para sua conservação. Nós testamos as diferenças na composição, riqueza e abundância de aves em diferentes fitofisionomias da Serra da Bodoquena, oeste do Brasil, e demonstramos as variações na riqueza e abundância de aves entre diferentes grupos tróficos. As amostragens foram conduzidas entre Julho de 2011 e Junho de 2012 em 200 pontos de escuta distribuídos na área de estudo. Foram obtidos 3350 contatos pertencentes a 156 espécies de aves. Savanas florestadas, florestas estacionais e savanas arborizadas tiveram maior riqueza e abundância de aves, enquanto florestas ripárias, pastos limpos e pastos sujos tiveram menores valores destes parâmetros. A comunidade de aves foi organizada de acordo com o gradiente local de vegetação, com comunidades de florestas, áreas abertas e savanas, embora muitas espécies tenham ocorrido em mais de um tipo de vegetação. As aves insetívoras, onívoras, frugívoras e granívoras compreenderam a maioria da comunidade. Estes dados demonstraram quão importante é a heterogeneidade ambiental para as comunidades de aves. Além disso, a presença de extensas manchas de habitats naturais, a pequena distância entre estas manchas e a permeabilidade das pastagens, com alta cobertura arbórea e arbustiva, são apontadas como importantes fatores para a manutenção da diversidade de aves.

ABSTRACT The informations of bird species distribution in different habitats and the structure of their communities are crucial for bird conservation. We tested the differences in composition, richness and abundance of birds in different phytophysiognomies at Bodoquena Mountains, western Brazil, and we demonstrated the variations in richness and abundance of birds between different trophic groups. Sampling was conducted between July 2011 and June 2012 in 200 point counts arranged in the study area. A total of 3350 contacts were obtained belonging to 156 bird species. Woodland savannas, seasonal forests and arboreal savannas had higher bird abundance and richness, while riparian forests, clean pastures and dirty pastures had smaller values of these parameters. The bird community was organized according to local vegetational gradient, with communities of forests, open areas and savannas, although many species occurred in more than one vegetation type. The insectivorous, omnivorous, frugivorous and gramnivorous birds composed most of the community. These data showed how important environmental heterogeneity is to bird communities. Furthermore, the presence of extensive patches of natural habitats, the small distance between these patches and the permeability of pastures, with high arboreal and shrubby cover, are indicated as important factors to maintain the bird diversity.