17 research outputs found

    Subtle effects of environmental stress observed in the early life stages of the Common frog, Rana temporaria

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    Worldwide amphibian populations are declining due to habitat loss, disease and pollution. Vulnerability to environmental contaminants such as pesticides will be dependent on the species, the sensitivity of the ontogenic life stage and hence the timing of exposure and the exposure pathway. Herein we investigated the biochemical tissue ‘fingerprint’ in spawn and early-stage tadpoles of the Common frog, Rana temporaria, using attenuated total reflection- Fourier-transform infrared (ATR-FTIR) spectroscopy with the objective of observing differences in the biochemical constituents of the respective amphibian tissues due to varying water quality in urban and agricultural ponds. Our results demonstrate that levels of stress (marked by biochemical constituents such as glycogen that are involved in compensatory metabolic mechanisms) can be observed in tadpoles present in the pond most impacted by pollution (nutrients and pesticides), but large annual variability masked any inter-site differences in the frog spawn. ATR-FTIR spectroscopy is capable of detecting differences in tadpoles that are present in selected ponds with different levels of environmental perturbation and thus serves as a rapid and cost effective tool in assessing stress-related effects of pollution in a vulnerable class of organism

    Molecular variability in Amerindians: widespread but uneven information

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    A habilidade de atenção auditiva sustentada em crianças com fissura labiopalatina e transtorno fonológico Sustained auditory attention ability in children with cleft lip and palate and phonological disorders

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    OBJETIVO: Verificar a habilidade de atenção auditiva sustentada em crianças com fissura labiopalatina e transtorno fonológico, comparando o desempenho com crianças com fissura labiopalatina e ausência de transtorno fonológico. MÉTODOS: Dezessete crianças com idade entre 6 e 11 anos, com fissura labiopalatina transforame unilateral operada e ausência de queixa e/ou alteração auditiva, separadas em dois grupos: GI (com transtorno fonológico) e GII (com au&#349;encia de transtorno fonológico). Para detecção de alteração auditiva foram realizadas audiometria e timpanometria. Para avaliação fonológica foram utilizados os seguintes instrumentos: Teste de Linguagem Infantil e Consciência Fonológica: Instrumento de Avaliação Sequencial. Para avaliar a habilidade de atenção auditiva foi aplicado o Teste da Habilidade de Atenção Auditiva Sustentada. RESULTADOS: Das sete crianças com transtorno fonológico (41%), duas (29%) apresentaram alteração nos resultados do Teste da Habilidade de Atenção Auditiva Sustentada. Não houve diferença entre as crianças com fissura labiopalatina e transtorno fonológico e as crianças com fissura labiopalatina e ausência de transtorno fonológico quanto aos resultados do Teste de Habilidade de Atenção Auditiva Sustentada. CONCLUSÃO: A habilidade de atenção auditiva sustentada nas crianças com fissura labiopalatina e transtorno fonológico não difere da habilidade de atenção auditiva sustentada de crianças com fissura labiopalatina sem transtorno fonológico.<br>PURPOSE: To verify the ability of sustained auditory attention in children with cleft lip and palate and phonological disorder, in comparison with the performance of children with cleft lip and palate and absence of phonological disorder. METHODS: Seventeen children with ages between 6 and 11 years, with repaired unilateral complete cleft lip and palate and absence of auditory complaints or hearing problems, were divided into two groups: GI (with phonological disorder) and GII (absence of phonological disorder). Audiometry and tympanometry were carried out to detect hearing problems. To diagnose phonological disorder, the following instruments were used: Child Language Test, and Phonological Awareness: Instrument of Sequential Assessment. The ability of auditory attention was assessed using the Test of Sustained Auditory Attention Ability. RESULTS: From seven children with phonological disorder (41%), two (29%) had altered results in the Test of Sustained Auditory Attention Ability. There was no difference between children with cleft lip and palate and phonological disorder and children with cleft lip and palate and absence of phonological disorder regarding the results of the Test of Sustained Auditory Attention Ability. CONCLUSION: The sustained auditory attention ability in children with cleft lip and palate and phonological disorder do not differ from the sustained auditory attention ability of children with cleft lip and palate without phonological disorder

    Effect of Super-Oxidized Water, Sodium Hypochlorite and EDTA on Dentin Microhardness

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    The present study aimed to evaluate the influence of the following irrigating solutions on the microhardness of root canal dentin: 2% sodium hypochlorite (2NaOCl), 5% sodium hypochlorite (5NaOCl), super-oxidized water (400 ppm Sterilox - Sx) and 17% EDTA (E). Eighty roots from bovine incisors were randomly divided into 8 groups (n=10): 2NaOCl, 5NaOCl, Sx, and 2NaOCl + E, 5NaOCl + E, Sx + E (associated with E as final irrigant for 5 min), E solely and distilled water (dH2O) as the negative control. Root canal preparation was performed by hand instruments, using one of the irrigation protocols for 30 min. Then, 5 mm of the cervical root third were cut out from each sample and subjected to the Vickers microhardness test, at two points, one at approximately 500-1000 μm from the root canal lumen (distance 1), and the other at approximately 500-1000 μm from the external root surface (distance 2). Data were analyzed by Wilcoxon and Kruskal-Wallis tests at 5% significance level. Microhardness values at distance 1 were significantly lower than those at distance 2 for all groups, except 5NaOCl and 5NaOCl + E groups (p>0.05). EDTA showed the lowest microhardness values. However, no statistically significant difference was detected among groups at distance 1 and EDTA was significantly different only from Sx at distance 2. In conclusion, all tested solutions showed lower microhardness at the most superficial root canal dentin layer compared to the one found near the external root surface, except 5NaOCl and 5NaOCl + E; EDTA promoted lower microhardness values in comparison to Sterilox at this site.O presente estudo teve como objetivo avaliar a influência das seguintes soluções irrigadoras na microdureza da dentina do canal radicular: hipoclorito de sódio a 2% (NaOCl2), hipoclorito de sódio a 5% (NaOCl5), água superoxidada (Sterilox ® 400 ppm - Sx) e EDTA a 17% (E). Oitenta raízes de incisivos bovinos foram divididas aleatoriamente em 8 grupos (n=10): NaOCl2, NaOCl5, Sx e NaOCl2 + E, NaOCl5 + E, Sx + E (associados ao E como irrigante final por 5 min), E isolado e água destilada (H2Od), como controle negativo. O preparo dos canais radiculares foi realizado com instrumentos manuais, usando um dos protocolos de irrigação por 30 min. A seguir, 5 mm do terço cervical de cada amostra foram cortados perpendicularmente e submetidos ao teste de microdureza de Vickers, em dois pontos, um aproximadamente 500-1000 μm da luz do canal radicular (distância 1), e o outro aproximadamente 500-1000 μm da superfície externa da raiz (distância 2). Os dados foram analisados pelos testes de Wilcoxon e Kruskal-Wallis com um nível de significância de 5%. Os valores de microdureza na distância 1 foram significativamente menores do que na distância 2 para todos os grupos, exceto NaOCl5 e NaOCl5 +E (p>0,05). O EDTA mostrou os menores valores de microdureza. No entanto, não foi detectada diferença estatisticamente significativa entre os grupos na distância 1 e o EDTA foi significativamente diferente apenas do Sx na distância 2. Pode-se concluir que todas as soluções testadas mostraram menor microdureza na camada de dentina mais superficial do canal radicular em comparação aos valores encontrados próximo à superfície radicular externa, exceto NaOCl5 e NaOCl5 + E; o EDTA promoveu menor microdureza em comparação ao Sterilox ® neste ponto
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