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• RESUMO: O presente trabalho tem o objectivo central de avaliar o desenvolvimento fonológico de crianças nascidas com muito baixo peso, contribuindo com evidência empírica para a reflexão sobre o papel das variáveis fonológicas na avaliação do desenvolvimento linguístico infantil. Foi implementado um estudo com 30 crianças na faixa etária dos 3 anos e 6 meses aos 4 anos e 6 meses, sendo que 15 pertenciam à população de crianças nascidas com muito baixo peso e as restantes à de crianças nascidas com peso adequado, emparelhadas por género e idade. Observou-se o desempenho segmental das crianças nos dois grupos em estudo, avaliando-se a relação entre a produção das consoantes do inventário segmental do Português Europeu e a sua distribuição em função das variáveis fonológicas posição na palavra, posição na sílaba e acento de palavra. O objectivo central foi o de testar a eficácia das variáveis fonológicas acima referidas na identificação de diferenças de desenvolvimento fonológico entre os dois grupos de crianças. Através do teste de QuiQuadrado e da comparação frequencial, verificou-se que as crianças nascidas com muito baixo peso apresentavam um desempenho verbal inferior ao das crianças com peso adequado, no que diz respeito às variáveis fonológicas testadas.• PALAVRAS-CHAVE: Crianças de muito baixo peso. Desenvolvimento fonológico. Palavra. Sílaba. Constituintes silábicos. Acento de palavra. ASPECTOS FONOLÓGICOSVários trabalhos sobre o desenvolvimento linguístico infantil têm identificado e/ou testado, nas últimas três décadas, as variáveis linguísticas com impacto na aquisição de diferentes sistemas gramaticais, tanto em contexto monolingue como bilingue. Este trabalho tem sido determinante para a definição da forma como o conhecimento linguístico se estrutura no processo de desenvolvimento cognitivo infantil, contribuindo, assim, para a validação de modelos teóricos

In recent years, various studies and development using nanoparticles (NPs) have been carried out in the most diverse areas of knowledge. Although nanomaterials are widely employed by many sectors and some may have a fertilizing potential, little is known about their effects on the environment. This study aimed to evaluate the effect of applying, in tropical natural soil, different contents of nanoparticles of zinc oxide (NPs-ZnO) and non-nano zinc oxide (ZnO) on soil pH and on the survival and reproduction rates of earthworms (Eisenia andrei) and springtails (Folsomia candida) through standardized ecotoxicological tests. The tests used a tropical soil representative of Brazil, classified as Entisol (Neossolo Quartzarênico órtico típico) with no history of agricultural use, collected in the 0.00-0.20 m layer, previously sieved (2-mm mesh) and defaunated. The experimental design was completely randomized, and treatments consisted of two forms of zinc (Zn), NPs-ZnO and ZnO, at the following doses: 0, 50, 100, 200, 400, 800, 2,000, and 4,000 mg kg-1. Standardized ecotoxicological tests showed no toxicity of NPs-ZnO in terms of lethality of E. andrei and F. candida. In E. andrei reproduction tests, NPs-ZnO were toxic at doses higher than 400 mg kg-1 (EC 50 of 1,021 mg kg-1). Tests with F. candida demonstrated that its reproduction rate was significantly affected by NPs-ZnO at a rate of 4,000 mg kg-1 (EC 50 of 3,636 mg kg-1). When used in Entisol, the NPs-ZnO inhibit the reproduction of earthworms and springtails; earthworms are more sensitive to such an effect, it being demonstrate at lower contents than those found for springtails.

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The Ria Formosa coastal lagoon is a highly productive shallow ecosystem in southern Portugal, subjected to nutrient inputs from anthropogenic and natural sources. Nutrients are major abiotic drivers of phytoplankton in this system, but their effects on phytoplankton assemblages and the occurrence of nutrient limitation are still poorly understood. The main goal of this study was, thus, to evaluate the occurrence, type, and effects of nutrient limitation on phytoplankton community and specific functional groups in the Ria Formosa coastal lagoon. We conducted nutrient enrichment experiments with factorial additions of nitrogen (N) and phosphorus (P) using natural phytoplankton assemblages from distinct locations in the Ria Formosa, throughout a yearly cycle. Phytoplankton composition and abundance were evaluated using inverted and epifluorescence microscopies, and spectrophotometric methods were used for biomass. Limitation was defined as higher phytoplankton growth following enrichment with a particular nutrient in relation to the non-enriched control. The most common type of phytoplankton limitation was simultaneous co-limitation by N and P; diatoms, as r-strategists, were the most frequently limited group. Single N and P limitation, and serial P limitation were also observed, as well as negative responses to nutrient enrichment. Group-specific responses to nutrient enrichment were not reflected in the relative abundance of phytoplankton groups within the whole assemblage, due to the numerical dominance of pico-sized groups (cyanobacteria and eukaryotic picophytoplankton). Ambient nutrient ratios and concentrations did not predict phytoplankton nutrient limitation, given the different nutrient utilisation traits among phytoplankton functional groups. Therefore, nutrient ratios should not be used as indicators of nutrient limitation in eutrophication assessment.

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