In a survey of levels of acesulfame-K and aspartame in soft drinks and in light nectars, the intake of these intense sweeteners was estimated for a group of teenage students. Acesulfame-K was detected in 72% of the soft drinks, with a mean concentration of 72 mg l(-1) and aspartame was found in 92% of the samples with a mean concentration of 89 mg l(-1). When data on the content of these sweeteners in soft drinks were analysed according to flavour, cola drinks had the highest mean levels for both sweeteners with 98 and 103 mg l(-1) for acesulfame-K and aspartame, respectively. For soft drinks based on mineral water, aspartame was found in 62% of the samples, with a mean concentration of 82 mg l(-1) and acesulfame-K was found in 77%, with a mean level of 48 mg l(-1). All samples of nectars contained acesulfame-K, with a mean concentration of 128 mg l(-1) and aspartame was detected in 80% of the samples with a mean concentration of 73 mg l(-1). A frequency questionnaire, designed to identify adolescents having high consumption of these drinks, was completed by a randomly selected sample of teenagers (n = 65) living in the city of Coimbra, in 2007. The estimated daily intakes (EDI) of acesulfame-K and aspartame for the average consumer were below the acceptable daily intakes (ADIs). For acesulfame-K, the EDI was 0.7 mg kg(-1) bw day(-1) for soft drinks, 0.2 mg kg(-1) bw day(-1) for soft drinks based on mineral waters, and 0.5 mg kg(-1) bw day(-1) for nectars, representing 8.0%, 2.2%, and 5.8% of the ADI, respectively. A similar situation was observed for aspartame. In this way, the EDI for soft drinks was 1.1 mg kg(-1) day(-1), representing only 2.9% of the ADI. In respect of nectars, the EDI was 0.2 mg kg(-1) bw day(-1), representing 0.5% of the ADI. Soft drinks based on mineral waters showed the lowest EDI values of 0.3 mg kg(-1) bw day(-1), accounting for 0.7% of the ADI.

Geographic information system analysis and artificial neural network modelling were combined to evaluate forest-fire susceptibility in the Central Portugal administrative area. Data on forest fire events, indicated by burnt areas during the years from 1990 to 2007, were identified from official records. Topographic, supporting infrastructures, vegetation cover, climatic, demographic and satellite-image data were collected, processed and integrated into a spatial database using geographic information system techniques. Eight fire-related factors were extracted from the collected data, including topographic slope and aspect, road density, viewsheds from fire watchtowers, land cover, Landsat Normalised Difference Vegetation Index, precipitation and population density. Ratings were calculated for the classes or categories of each factor using a frequency-probabilistic procedure. The thematic layers (burnt areas and fire-related factors) were analysed using an advanced artificial neural network model to calculate the relative weight of each factor in explaining the distribution of burnt areas. A forest-fire susceptibility index was calculated using the trained back-propagation artificial neural network weights and the frequency-probabilistic ratings, and then a general forest-fire susceptibility index map was constructed in geographic information system. Burnt areas were used to evaluate the forest-fire susceptibility index map, and the results showed an agreement of 78%. This forest-fire susceptibility map can be used in strategic and operational forest-fire management planning at the regional scale.

Maria do Carmo Bezerra & Mona-Lisa Choas artigo 39 integração de modeloS de SimUlação em Sig: aplicação ao caSo da drenagem de ágUaS plUviaiS UrBanaS.

<p>Starting from a revisitation of the Cultural Geomorphology concept, this work focuses on the use of Geographic Information Technologies to create and enrich content used to support the appreciation and management of the natural characteristics of places (geodiversity) in the context of their valorisation as an endogenous tourist resource.</p><p>A territory roughly delimited by the tops of the Arada and S. Macário mountains and the valleys of the rivers Sul and Vouga (municipality of São Pedro do Sul) was selected as the study area, primarily because it is a place of significant geomorphological interest, but also because this geoheritage can be used as a complementary tourist resource to the existing spa activities linked to geothermal springs and, in this way, contribute to a reinforcement and diversification of available tourist offer.</p><p>Pursuing that main goal, in this work several selected examples are presented to illustrate the potential value associated with the use of Geographic Information Technologies, both for the collection of data in the field and subsequent elaboration of thematic contents tailored to different segments of public, and for the development of a digital platform aimed to support geotourism activities or environmental education events. These are two lines of intervention that can be of great significance to improving public perception for the value of natural and cultural landscapes, particularly in regions with significant problems of depopulation and rural abandonment as is the case of the selected study area.</p>