61 research outputs found

    Effects of external nutrient sources and extreme weather events on the nutrient budget of a Southern European coastal lagoon

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    The seasonal and annual nitrogen (N), phosphorus (P), and carbon (C) budgets of the mesotidal Ria Formosa lagoon, southern Portugal, were estimated to reveal the main inputs and outputs, the seasonal patterns, and how they may influence the ecological functioning of the system. The effects of extreme weather events such as long-lasting strong winds causing upwelling and strong rainfall were assessed. External nutrient inputs were quantified; ocean exchange was assessed in 24-h sampling campaigns, and final calculations were made using a hydrodynamic model of the lagoon. Rain and stream inputs were the main freshwater sources to the lagoon. However, wastewater treatment plant and groundwater discharges dominated nutrient input, together accounting for 98, 96, and 88 % of total C, N, and P input, respectively. Organic matter and nutrients were continuously exported to the ocean. This pattern was reversed following extreme events, such as strong winds in early summer that caused upwelling and after a period of heavy rainfall in late autumn. A principal component analysis (PCA) revealed that ammonium and organic N and C exchange were positively associated with temperature as opposed to pH and nitrate. These variables reflected mostly the benthic lagoon metabolism, whereas particulate P exchange was correlated to Chl a, indicating that this was more related to phytoplankton dynamics. The increase of stochastic events, as expected in climate change scenarios, may have strong effects on the ecological functioning of coastal lagoons, altering the C and nutrient budgets.Portuguese Science and Technology Foundation (FCT) [POCI/MAR/58427/2004, PPCDT/MAR/58427/2004]; Portuguese Science and Technology Foundation (FCT

    Integrated sensory motor system in prematurely born children

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    Objetivo: Investigar a existência de sistema sensório motor integrado em recém-nascidos (RNs) prematuros submetidos à estimulação gustativa. Métodos: Estudo experimental analítico e duplo-cego. Participaram 90 RNs prematuros, divididos em dois grupos (água e sacarose para análise (PA) 12%), filmados durante 15 minutos (primeiro e último momentos, sem estimulação; e segundo momento com estimulação gustativa). Três juízes independentes analisaram os comportamentos mão na boca direita e esquerda e sucção da mão direita e esquerda durante os diversos estados comportamentais, inseridos no banco de dados do Statistical Package for Social Science, sendo considerados em concordância os eventos observados por pelo menos dois deles. Empregou-se teste de correlação de Spearman com nível de significância valor de p<0,05. Resultados: Tanto ao serem considerados os grupos separadamente quanto juntos, mão na boca direita e esquerda tiveram inicialmente correlação moderada, sendo que mão na boca direita manteve-se forte no final e mão na boca esquerda finalizou com correlação moderada e forte, de acordo com cada estado comportamental. Sucção de mão direita na totalidade e em sacarose apresentou-se inicialmente com correlação forte no estado sonolento, passando para moderada ao final. No estado alerta houve inicialmente correlação fraca em ambos os estímulos, finalizando com correlação moderada em sacarose e forte em água. Sucção de mão esquerda apresentou-se inicialmente correlação moderada em alerta, finalizando com correlação fraca no grupo sacarose, o que não ocorreu na água, que iniciou e finalizou forte. Conclusão: A estimulação oral influenciou na coordenação mão-boca, independente do estímulo, evidenciando integração sensório motora precoce, mas não inferindo sobre capacidade de discriminação gustativa nos prematuros. _________________________________________________________________________________________ ABSTRACT: Purpose: To investigate about an integrated sensory motor system existence in premature newborns, submitted to gustatory stimulation. Methods: Analytical and experimental study of contents, double-blind. Being participants 90 premature newborns, divided into two groups (water or sucrose analysis 12%). Recorded by 15 minutes (first and last moments, without stimulation; and second time with gustatory stimulation). Three independent judges analyzed the behaviors in the right hand and left hand in the mouth and suction in the left and right and hand during the various behavioral states, those being inserted in the database of Statistical Package for Social Science, being then considered that the events observed by at least two of them. It was made use of Spearman’s rank correlation test on a significance level by p<0.05. Results: Considering the groups both separately and together, right and left had initially moderate correlation, being right hand in the mouth remained strong at the end and left hand in the mouth finished on moderate and strong correlation, according to each behavioral state. Right hand suction in its total and sucrose showed a strong correlation initially in drowsy state, becoming moderate at the end. In alertness state there was initially a weak correlation in both stimuli ending in moderate correlation in sucrose and strong in water. Left hand suction presented initially moderate correlation on the alert state, ending in weak correlation in sucrose stimuli, which did not occur in the water that started and finished strong. Conclusion: The oral stimulation influenced the hand-mouth coordination, showing early motor sensory integration. However, there was no discrimination about the gustatory capacity on the newborns

    Mycorrhizas in South American Anthropic Environments

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    The agricultural expansion has leaded to increase the irrigated cropland area and the use of fertilizers, resulting in water degradation, increased energy use, and common pollution. Of particular concern is the increased interest to reduce the environmental impacts of high quantities of water dedicated to irrigation by agricultural activities We are now truly recognizing the importance of sustainable measures in agriculture such as conservation of the vegetation cover and management approach to understand surface and deep soil responses to global change. The agroecology management based on key processes from natural ecosystems can help to solve some agricultural difficulties. Increasing studies on the Arbuscular mycorrhizal fungi (AMF) has showed their importance for soil ecology and studies on their biodiversity have spread in some agro-ecosystems such as corn and soybean monocultures. Therefore, it is needed to deeply study the mycorrhizal functions under global change. In this chapter, we examine the major developments and advances on mycorrhizal fungi based on recent research from South American countries. New reports on the occurrence of mycorrhizas in Amazonian dark earth, as well as the inoculum production of arbuscular mycorrhizal fungi native of soils under native forest covers, have resulted in a more detailed understanding of the soil biology from South America. Reports from Amazonian dark earth or “Terra preta do índio” soil has stimulated the use of biochar worldwide as a soil conditioner that can add value to non-harvested agricultural products and promote plant growth. Few reports from Brazil showed that the addition of inorganic fertilizer, compost and chicken manure resulted in increases in plant cover and plant species richness. In this sense, the biochar/mycorrhizae interactions also can be prioritized for sequestration of carbon in soils to contribute to climate change mitigation
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