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This study evaluated the Limnoperna fortunei (golden mussel) as a bioindicator of cytotoxicity and genotoxicity in aquatic environments contaminated by heavy metals. Five groups of 50 subjects each were exposed to different concentration of mercuric chloride (HgCl2) (0.001 mg/L, group I; 0.005 mg/L, group II; 0.01 mg/L, group II; 0.02 mg/L, group IV; and 0.1 mg/L, group V). The control group for both chronic and acute treatment did not receive HgCl2. For chronic exposure, the respective groups were placed in aquaria with water contaminated with the above concentrations of HgCl2. For acute exposure, the different concentrations of HgCl2 were injected into the posterior adductor muscle of the individuals belonging to the aforementioned groups. The biological matrix used in the tests was the whole body muscle. Tests (cell viability assay, alkaline comet test; enumeration of micronuclei and necrotic cells, quantification of Hg content in tissues and water, and histopathological analysis of tissues), were carried out on the 7th, 15th, and 30th treatment days or 2 h after injection. Our results demonstrated that L. fortunei showed cell damage in both chronic and acute exposure groups. Significant DNA damage was observed at both the 15th (0.1 mg/L) and 30th (0.01–0.1 mg/L) days of chronic exposure. However, in acute treatment all concentrations induced DNA breaks. The presence of necrosis increased at all concentrations tested for both acute and chronic exposure. Tissue mercury retention on the 15th day was higher than on the 30th day of exposure, while in the same period, there was a decrease in the mercury content of aquarium water. Taking the data together, it is concluded that L. fortunei as a possible bioindicator of the quality of aquatic environments.

DOI: http://dx.doi.org/10.14244/19827199651 In the present study, we analyze the conceptions of the Sciences discipline of educators and students from Basic Education in a school within a unit of restriction of freedom in the municipality of Uruguaiana, Rio Grande do Sul state, Brazil. Furthermore, we sought to identify which strategies were adopted to teach Sciences in this environment in order to provide a process aimed at rehabilitation and scientific literacy. Data were collected through semi-structured questionnaires and qualitative assessment was carried out according to content analysis. The results showed that the conceptions of the Sciences discipline were varied and extensive, specially those of students. It was possible to observe that the teaching strategies used may hinder the process of scientific literacy, probably because of the security issues within the school. However, as an alternative to overcome these problems, we suggest the continuing education of teachers and the development of educational strategies from the use of the Sciences discipline as a tool to make lessons more interesting and promote civic education. Keywords: Teaching Sciences, Conceptions, Places with restriction of freedom.

O presente trabalho registra a ocorrencia do mexilhao dourado Limnoperna fortunei (Dunker, 1857) em ambiente natural no municipio de Uruguaiana, Fronteira Oeste do Rio Grande do Sul, Pampa Brasileiro. Os aglomerados da especie foram detectados, fotografados e coletados na margem esquerda do rio Uruguai, em territorio brasileiro, em dois locais distintos, sendo o primeiro proximo a Ponte Internacional Getulio Vargas - Agustin Justo, que faz divisa entre as cidades de Uruguaiana/Brasil e Paso de Los Libres/Argentina e o segundo proximo a foz do arroio Salso, afluente do rio Uruguai. Os animais foram capturados e levados para laboratorio onde foram identificados e armazenados.

This study assessed the limnology from the Medium Uruguay River Basin in Uruguaiana, Brazil, with a focus on the concentration of heavy metals (Cd, Cu, and Mn), to assess the toxicological potential (cytotoxicity and genotoxicity) for humans using as biological matrix of study human leukocyte cells. The conductivity, resistivity, and dissolved O2 levels exceeded the limits recommended by the National Environmental Council (Conselho Nacional do Meio Ambiente - CONAMA). The percentage of non-viable human leukocyte cells exposed to water samples was approximately 20% higher than that of the negative control (

The use of plants as a source of palliative or cure for pathological conditions is quite common worldwide. Xanthium spinosum (Asteraceae), popularly known in Brazil as 'espinho de carneiro', is an annual weed from South America, which has been used by empiric medicine to treat neoplasias. Owing to the extensive use of the above-mentioned plant and to the lack of reports about the real effects of its infusion, current study evaluated the genotoxic potential of its aqueous extract at concentrations 0.02 g L-1, 0.1 g L-1 and 0.2 g L-1 by fish micronucleus test and by comet human leukocytes assay. The micronucleus test featured at least 50 cells with micronuclei to every 2,000 cells scored, as a mutagenic parameter. The comet assay was used as a parameter for assessing the level of cell damage and the damage index. Since no significant changes in strain cells exposed to the aqueous extract in the comet and micronucleus assays were reported, it seems that no genotoxicity evidence is extant at the concentrations and in the assays performed.Em diversos lugares do mundo a utilização de plantas como fonte paliativa ou de cura para determinadas condições patológicas é bastante comum. No Brasil, essa prática não se torna diferente devido à ampla biodiversidade da fauna e flora presentes no País. Nesse contexto, surge a Xanthium spinosum (Asteraceae), conhecida popularmente como "espinho-de-carneiro", um arbusto anual introduzido na América do Sul, o qual tem sido utilizado empiricamente no tratamento de neoplasias. Sabendo do extensivo uso dessa planta em contrapartida com nenhum estudo reportando os reais efeitos de sua infusão, o objetivo do estudo foi avaliar a genotoxicidade do extrato aquoso nas concentrações de 0,02 g L-1, 0,1 g L-1 e 0,2 g L-1, através do ensaio do micronúcleo písceo e do ensaio cometa em leucócitos de sangue humano. O ensaio do micronúcleo tem como parâmetro mutagênico a presença de no mínimo 50 células com micronúcleo em uma contagem de 2.000 células por amostra, enquanto o ensaio cometa utiliza como parâmetro o nível de dano e o índice de dano. Os resultados mostram que não foi possível observar mudanças significativas nas células expostas ao extrato aquoso, em ambos os testes, o que sugere não existir evidência de genotoxicidade nas concentrações utilizadas no ensaio.

http://dx.doi.org/10.5007/2175-7925.2014v27n2p87 O cascudo Hypostomus commersoni, nativo da Bacia do Rio Uruguai, pertencente à família Loricariidae, é encontrado habitualmente em ambientes lênticos e tem sua biologia ainda pouco conhecida na região do Pampa Brasileiro. Foi verificado o período reprodutivo pela análise da variação mensal do índice gonadossomático (IGS), do índice hepatossomático (IHS), e o fator de condição gonadal (∆K), além da observação macroscópica do estádio de desenvolvimento gonadal. Após a análise dos resultados pode se concluir que a espécie em estudo tem seu período reprodutivo de setembro estendendo-se a janeiro, atingindo seu pico de reprodução em novembro. Os indicadores IHS e ∆K apresentaram-se mais elevados no mês de outubro, demonstrando uma melhor condição gonadal e o IHS revelou um acúmulo de reservas lipídicas para fornecer energia na vitelogênese, no mês antecedente ao pico de reprodução, sendo desta forma, bons indicadores que corroboram com o período de reprodução determinado.

O escorpião amarelo Tityus serrulatus é registrado pela primeira vez para oeste do Rio Grande do Sul. Foram coletados dois espécimes no município de Uruguaiana (29° 45' 23'' S e 57° 05' 37'' W) em junho de 2006. A ocorrência dos espécimes de T. serrulatus no Rio Grande Sul representa um aumento de 2.127 km em sua área de distribuição conhecida. The yellow scorpion Tityus serrulatus is recorded for the first time for the western Rio Grande do Sul State, Brazil. Two specimens were collected in the municipality of Uruguaiana (29° 45' 23'' S and 57° 05' 37'' W) in june 2006. The occurrence of specimens of T. serrulatus in Rio Grande do Sul represents an increase of 2127km in relation to his known distribution area.

The recruitment period of Locariichthys platymetopon (Isbrucker & Nijssen, 1979) was investigated. It has been found out, through the data analysis, that the gonadal condition factor is a good indicator of the reproductive period and that the hepatossomatic index is probably related to the storage of reservation for the winter period. The recruitment occurred in November coinciding with the reproductive activity of May.