ESTM - Artigos em revistas internacionais
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- An empirical comparison of Canonical Correspondence Analysis and STATICO in the identification of spatio-temporal ecological relationshipsPublication . Mendes, Susana; Fernández-Gómez, M. José; Pereira, Mário Jorge; Azeiteiro, Ulisses Miranda; Galindo-Villardón, M. PurificaciónThe wide-ranging and rapidly evolving nature of ecological studies mean that it is not possible to cover all existing and emerging techniques for analyzing multivariate data. However, two important methods enticed many followers: the Canonical Correspondence Analysis (CCA) and the STATICO analysis. Despite the particular characteristics of each, they have similarities and differences, which when analyzed properly, can, together, provide important complementary results to those that are usually exploited by researchers. If on one hand, the use of CCA is completely generalized and implemented, solving many problems formulated by ecologists, on the other hand, this method has some weaknesses mainly caused by the imposition of the number of variables that is required to be applied (much higher in comparison with samples). Also, the STATICO method has no such restrictions, but requires that the number of variables (species or environment) is the same in each time or space.Yet, the STATICO method presents information that can be more detailed since it allows visualizing the variability within groups (either in time or space). In this study, the data needed for implementing these methods are sketched, as well as the comparison is made showing the advantages and disadvantages of each method. The treated ecological data are a sequence of pairs of ecological tables, where species abundances and environmental variables are measured at different, specified locations, over the course of time.
- Short-term impacts of air temperature on hospitalizations for mental disorders in LisbonPublication . Almendra, Ricardo; Loureiro, Adriana; Silva, Giovani; Santana, Paula; Vasconcelos, JoãoIndividuals with mental disorders are often susceptible to the effects of extreme ambient temperatures. The aim of this study is to assess the short-term impacts of daily mean temperature on hospitalizations for mental disorders in the Lisbon Metropolitan Area, Portugal. Methods: To assess the short-term impacts of daily mean temperature on hospitalizations for mental disorders (2008–2014), a quasi-Poisson generalized additive model combined with a distributed lag non-linear model was applied. The model was adjusted for day of the week, air pollution, relative humidity, time and seasonality. Results: The number of hospital admissions for mental disorder during the study period was 30,139. Hospital admissions increase significantly with high temperatures on day of exposure, at lag 0–1 and at lag 0–2.Women are more vulnerable than men, and there was no difference between the age groups studied. Conclusions: The exposure to high temperatures should be considered a significant risk factor for mental disorders; therefore, patient management services may need to be strengthened when extreme high temperature alerts are given
- Amplified ribosomal DNA restriction analysis as a routine tool to assess toxicant driven changes in hindgut bacterial populations of Porcellio dilatatus (Crustacea: Isopoda)Publication . Santos, Miguel J. G.; Sousa, José Paulo; Tiago, Igor; Veríssimo, António; Lemos, MarcoChanges in saprophytic organism's gut microbial communities may present a threat to organic matter breakdown which can ultimately lead to soil function impairment. In this study, Amplified Ribosomal DNA Restriction Analysis (ARDRA) was evaluated as a potential simple molecular tool to assess shifts in bacterial community structure in hindgut populations of Porcellio dilatatus exposed to contaminated food. This prospective tool can also be used for a variety of purposes and samples prior to the use of more specific and sophisticated methods.
- Using multitable techniques for assessing the temporal variability of species–environment relationship in a copepod community from a temperate estuarine ecosystemPublication . Cotrim Marques, Sónia; Pardal, Miguel Ângelo; MENDES, SUSANA; Azeiteiro, Ulisses Manuel de MirandaThis study investigated copepod assemblages' distribution patterns and determined the main hydrological and physical factors structuring it at different temporal scales. Copepod and hydrographic surveys were conducted seasonally during a one-year period, at a fixed station in Mondego estuary. Hourly samples were collected, during a diel cycle from sub-surface and 1m above the bottom, at spring tides. Temporal variability of copepod community was analyzed using the STATICO method. Seasonal variability of the environmental conditions, linked with periods of higher freshwater flow, were the main drivers responsible for copepod community structure observed. Seasonal changes related to environmental factors showed to be strongest in spring and in winter, which accounted with higher species density. Marine and estuarine copepods showed maximal abundance in spring and summer, while the period of higher river flow, coincidently with autumn and winter, imposed changes in the copepods composition, emphasizing the changes in saline zonation within the estuary due to regime of river discharge. STATICO also emphasized the effects of physical forcing at short-term temporal scales. The stable part of the species–environment relationships resulted from the combination of a salinity gradient linked to a fresh, brackish- and marine species gradient, which was dependent on tidal cycle. The STATICO method proved to be a valuable statistical tool to get a clear representation of temporal organization of the copepod assemblages.
- Bioaccumulation and Elimination of Waterborne Mercury in the Midge Larvae, Chironomus riparius Meigen (Diptera: Chironomidae)Publication . Azevedo-Pereira, Henrique M. V. S.; Abreu, Sizenando N.; Lemos, Marco F.L.; Soares, Amadeu M. V. M.Here, mercury kinetics and behavioural effects in the midge larvae under a water-only exposure were assessed. Uptake and elimination of waterborne mercury were described by using a one-compartment kinetic model. Results show that midges were able to readily accumulate the heavy metal (BCF = 450), presenting a fast uptake, up to 13.1 lg Hg g of animal-1 at the end of the exposure period. Elimination was slow, with c.a. 39 % of the mercury in larvae being depurated after 48 h in clean medium. Behaviour did not present differences upon exposure or elimination, but a trend to increase ventilation was noticed during the exposure period.
- Immobilized heterologous Rhizopus oryzae lipase: A feasible biocatalyst for the production of human milk fat substitutesPublication . Tecelão, Carla; Guillén, Marina; Valero, Francisco; Ferreira-Dias, SuzanaThis work aims at evaluating the potentialities of a heterologous Rhizopus oryzae lipase (rROL) as a feasible biocatalyst, to be used as an alternative to commercial lipases, for the synthesis of Human Milk Fat Substitutes (HMFS). This enzyme was immobilized in three different supports (Accurel® MP 1000, Eupergit® C and Lewatit® VP OC 1600) and tested as catalysts for the acidolysis between tripalmitin and oleic acid, batchwise, at 60 ◦C, in solvent-free medium. The highest molar incorporations of oleic acid in the triacylglycerols were achieved with rROL in Lewatit® VP OC 1600 and Accurel® MP 1000, although the highest immobilization yields were observed with Eupergit® C. Quasi-equilibrium was attained after 6 h or 12 h reaction, with about 30 mol.% and 22 mol.% of oleic acid incorporation, when rROL immobilized in Lewatit and Accurel were used, respectively. Also, 23 h batch operational stability tests were performed: half-life times (t1/2) of 34.5 h and 64.0 h were achieved for rROL immobilized in Accurel® MP 1000 and in Lewatit® VP OC 1600, respectively. An important increase in the operational stability was observed for rROL immobilized in Lewatit after rehydration at the end of each batch (t1/2 = 202 h). Thus, the loss of activity may be explained by a progressive dehydration occurring along the reaction.
- Planning forest recreation: environmental economic instruments and the public participationPublication . Oliveira, F.; Pintassilgo, P.; Mendes, I.; Silva, J. A.In Portugal there is a growing demand for natural areas that provide a wide range of outdoor recreation. This paper focuses on the particular case of the Mata Nacional de Leiria (Leiria National Forest). This is a pine tree forest with 11,000 hectares and eight centuries of history. It has always been a public forest with open access to everyone, a fact that contributes to different kinds of use and benefits (walking, cycling, picnics, collecting firewood, fruits and berries, and other recreation activities). The proximity to a major urban and industrial centre, on one hand, and to a very popular beach coast, on the other, makes this a resource that is widely used by both residents and visitors. In the future there is the possibility of implementing a set of actions to improve forest amenities and recreation, and later the emergence of environmental tourism activities and equipment. In this context, we want to know the economic valuation that actual users attach to these recreation improvements, but also realize their preferences and opinions regarding this project. For this purpose we designed, tested and applied a double bounded dichotomous choice contingent valuation questionnaire. The results presented in this paper focus on responses to attitudinal and follow-up questions. More than 70% of respondents have positively assessed the proposed improvements to the study area and about 40% enhanced their personal opinion on the type of interventions that they consider most appropriate. Answers focus the priority areas of intervention in the Mata Nacional de Leiria, the main concerns in its development, the type of actions that should (and should not) be implemented, respondents willingness to actively take part and, also, what the public authorities' role should be. At this stage, where Mata Nacional de Leiria is being considered in terms of future recreation and tourism offers, the results obtained provide important contributions and enhance the contingent valuation survey as a tool to support recreation planning, promoting public participation and the political decision-making process.
- Tourism as a tool of community development: an ecotourism project in Cantanhez, Guinea-BissauPublication . Oliveira, F.; Silva, F.In recent decades the scientific community and various international organizations have provided a range of guidelines towards the development of more sustainable tourism. The responsible use of natural and cultural resources and the participation of local communities - with the involvement of the different actors in the development process - are inseparable aspects of sustainability's concept. However, when we try to put it into practice it appears that this is a very slow process, with many aspects that must be considered, especially in the case of underdeveloped regions. This paper focuses precisely on one of these regions - Cantanhez National Park, Guinea Bissau. This region has natural and cultural resources that are real treasures, which enhance the environmental and green forms of tourism; however, the structural problems of the country can be a real challenge to any type of initiative. The purpose of this communication is to present the ecotourism project in Cantanhez National Park, identifying the objectives, the first stages of the project implementation, the difficulties arising from the social, economic and political situation of the country and finally, its relevance in promoting community development. The realities that will be shared in this paper resulted from an initial visit to identify the needs of tourism planning, management and training in the communities directly involved.
- Historical separation and present-day structure of common dolphinfish (Coryphaena hippurus) populations in the Atlantic Ocean and Mediterranean SeaPublication . Maggio, Teresa; Allegra, Alessandro; Andaloro, Franco; Barreiros, João Pedro; Battaglia, Pietro; Butler, Christopher M; Cuttitta, Angela; Fontes, Miguel Rodrigues Jorge; Freitas, Rui; Gatt, Mark; Karakulak, F Saadet; Macias, David; Nicosia, Aldo; Oxenford, Hazel A; Saber, Samar; Yildiz, Taner; Sinopoli, Mauro; Vasco Rodrigues, Nuno; Grant, W StewartThe common dolphinfish (Coryphaena hippurus) is an epipelagic, mid-trophic level, highly migratory species distributed throughout the world’s tropical and subtropical oceans in waters greater than 20C. Life-history variables, migratory behaviour, and genetic markers have been used to define major stocks in the central Atlantic Ocean and Mediterranean Sea. Here, we used the mitochondrial DNA gene NADH subunit 1 (688 bp) to test for differences between population groups. A total of 103 haplotypes were detected among 203 fish. Gene diversities in samples were large and similar among populations (mean h ¼ 0.932; range 0.894–0.987), but nucleotide diversities varied widely among samples (range p ¼ 0.004–0.034) and appear to reflect population histories. Principal component analysis revealed two large populations groups, and the analysis of molecular variation and pairwise values of UST resolved population structure within these groups. Populations in the eastern Atlantic and Mediterranean showed the largest amounts of divergence from one another (UCT ¼ 0.331). Adult movement and biophysical barriers to larval dispersal may explain contemporary differences between stocks, but the divergent populations in the Mediterranean Sea are likely due to isolations by cold temperature barriers during Pleistocene glaciations. The geographically large stock groupings require international cooperation in the harvest management and conservation of local dolphinfish population
- The status of farmed fish hearts: an alert to improve health and production in three Mediterranean speciesPublication . Pombo, Ana; Blasco, Manuel; Climent, VicenteThe heart ventricles of farmed gilthead seabream (Sparus aurata), European seabass (Dicentrarchus labrax) and Senegalese sole (Solea senegalensis) have been examined and we compared them to the corresponding fish from wild populations. These results can help to understand the differences in farmed fish hearts and in the myocardial structure that this condition of growth can produce. Several parameters were measured in the two groups. Numerical comparisons included heart mass, cardiac and ventricular index, ventricle height:width ratio, width and alignment of bulbus arteriosus, ventricular angles and compacta thickness. We confirm that the normal shape of wild fish hearts can be modified as a result from the adaptation to different environments. These changes can modify the structure of myocardium and compromise the cardiac function in farmed species. The ventricle of farmed fish present differences in shape, were misaligned, rounder, with a wider bulbus and thinner compact layer. Further studies are necessary to reveal functional significance and possible causes of these abnormal hearts and improve the cardiac welfare of Mediterranean species in culture as a way of ensuring a level of production compatible with economic benefits.