4,573 research outputs found
Factors affecting the use of estuarine areas by waders : implications for their conservation
Tese de doutoramento em Biologia (Ecologia) apresentada à Universidade de Lisboa através da Faculdade de Ciências, 2009Estuarine intertidal flats are amongst the most important habitats for waders during the non-breeding season. These environments face increasing pressures from human activities, which are contributing to a general decline in wader populations. It is therefore essential to know the factors driving the use of intertidal flats by wintering waders, particularly their implications to the conservation of these species. The analysis of such factors was the main focus of this thesis, what was attained by answering several specific questions related with the use of sediment flats at different spatial scales, using the waders wintering in Tagus estuary as model. It was demonstrated that dunlins Calidris alpina avoid performing long flights between roost sites and foraging grounds, what highlights the importance of the maintenance of a network of good-quality roosts for waders in estuarine areas. It was also shown that species vary in their response to the tidal movement, what has large implications in the estimates of use of tidal areas. Upper tidal flats (which are under considerable threat due to their proximity to shoreline) proved to be particularly important in providing food resources for waders. The fine scale use of tidal areas was studied by testing several predictions related with the searching behaviour of waders. It was shown that only tactile species, as black-tailed godwits Limosa limosa, are expected to present an arearestricted search, a type of movement usually adopted by foragers in clumpy environments. Finally, it was evaluated the impacts of traditional shellfishing on waders. Current levels of shellfishing seem to be compatible with the preservation of the Tagus estuary as a key site for waders, but the predictable increase in disturbance due to urban expansion in the vicinity of the Tagus estuary can result in serious impacts on some wader species.Fundação para a Ciência e Tecnologia (SFRH/BD/19313/2004); projectos Sat-Tagis (PDCTM/C/MAR/15256/1999) e Pred-Tagis (POCTI/BSE/47569/2002
On the mental representation of (un)healthy tooth: (un)healthy tooth profiles among children
This is an open-access article distributed under the terms and conditions of the Creative Commons Attribution
license (http://creativecommons.org/licenses/by/3.0/)."Objectives: A descriptive study of exploratory character with the objective to determine the representation of a
healthy tooth and an unhealthy tooth, associated with the concept of dental decay. Methods: Children of both
genders (880), distributed in six age groups of low socio-economic level, some already having prior contact with
the dentist and others not. Three instruments were used: a sociodemographic questionnaire, pictograms
representation protocols and drawing content analysis grid. Results: Content analysis on the drawings indicates
significant discrepancies, inherent to the pictorial profiles. Conclusion: The results point to the need of
developing educative tools for oral health."Pierre Fabre Portuga
Passive systems for buildings using buoyancy-driven airflows
The need for countries to become less dependent on fossil fuels has been a determining factor in recent years due to increasing energy and comfort concerns in modern building design. Therefore, the maximization of the use of renewable energies, like the sun, and the use of natural energy flows become strategies to explore. There are already passive building systems that show interesting performances. Different studies have proved that the above-mentioned systems can lead to important energy savings. However, these systems have their limitations and new innovative building solutions are needed, mainly in the field of passive solar energy collection and natural ventilation strategies. Furthermore, building envelopes face nowadays a new paradigm in which buildings need to be more reactive and adaptive to external climate changes and indoor thermal comfort demands. Hence, this paper makes a review of the most recent patents on building solar air systems that make use of solar energy to induce the buoyancy effect for heating, cooling and ventilating. The patents presented demonstrate the increasing tendency in the development of building passive solutions that can satisfy, in just one system, more than one role: heating, cooling and ventilation.The present paper was performed within the framework of a research project on Low Energy/High Comfort Building Renewal, PTDC/ECM/67373/2006, sponsored by the Portuguese Foundation for Science and Technology (FCT)
Divulgação da informação contabilĂstica na campanha eleitoral autárquica: estudo exploratĂłrio
O presente estudo tem como objetivo analisar a divulgação da informação contabilĂstica
por parte dos polĂticos locaisna campanha eleitoral autárquica das Ăşltimas eleições (2013)
e identificar os fatores que potencialmente explicam essa divulgação, tomando como
referĂŞncia o caso especĂfico dos municĂpios de Trás os Montes e Alto Douro.
Os resultados mostram que os polĂticos locais tendem a divulgar a informação
contabilĂstica para fins de campanha eleitoral autárquica. O valor dos investimentos
realizados e das dĂvidas por pagar revelam ser os tipos de informação divulgados em
maior número. Os resultados permitiram ainda concluir que a divulgação da informação
contabilĂstica na campanha eleitoral autárquica Ă© influenciada pela dimensĂŁo do
municĂpio, pelo tipo de governação (maioria
ou minoria) do partido polĂtico do executivo e pelo montante das dĂvidas a pagar
Understanding the relationship between illness perceptions of breast cancer and perceived risk in a sample of U.A.E. female university students: the role of comparative risk
BMC Women's Health is an open access, peer-reviewed journal that considers articles on all aspects of the health and wellbeing of adolescent girls and women, with a particular focus on the physical, mental, and emotional health of women in developed and developing nations. The journal welcomes submissions on women's public health issues, health behaviours, breast cancer, gynecological diseases, mental health and health promotion.info:eu-repo/semantics/publishedVersio
Global changes in coastal wetlands of importance for non-breeding shorebirds
Shorebird declines are occurring worldwide but the causes are not fully understood. Recent literature suggests that the deterioration of habitat quality at their non-breeding areas, mostly located in temperate and tropical coastal wetlands, might be a major contributing factor. However, most studies carried out so far tend to be restricted to a few regions. Remote sensing can help correct such geographical bias on knowledge by providing a standardized approach on how shorebird habitats have been changing over the last few decades at a global scale. Here we analyzed time series of remote sensing classifications of tidal flats and land cover to quantify worldwide habitat changes in coastal Important Bird and Biodiversity Areas (IBAs) relevant for non-breeding shorebirds over the last two decades. Globally, supratidal areas (used as roosting habitat) have changed more significantly than tidal flats (used as feeding habitat). Yet, we found striking losses of tidal flats in IBAs distributed in several regions of the East Asian - Australasian Flyway. At supratidal areas, there was a general expansion of marshland, grassland and urban areas, contrasting with a decline of barren land, woodland and cropland. The expansion of marshland occurred in IBAs of most regions of the world. Urban areas also expanded consistently in supratidal areas within the most populated regions of the world. The loss of barren land is particularly concerning as it may translate into a loss of high-quality roosts and it was highly frequent in IBAs of all migratory flyways. Overall, our results confirm the large losses of shorebird habitat in the East Asian - Australasian Flyway reported in the literature, and highlight unreported generalized changes in supratidal habitats, such as the expansion of marshland and the loss of barren land, that may have negative implications for shorebirds, deserving further research and consideration in conservation programs.info:eu-repo/semantics/publishedVersio
Programas de apoio institucional ao empreendedorismo: a experiĂŞncia da Universidade do Minho
Em muitos paĂses tem sido feito um esforço significativo no sentido de promover o empreendedorismo. As universidades, dado o seu potencial de conhecimento e pesquisa, tĂŞm implementado programas de incentivo ao empreendedorismo, nomeadamente com a criação de gabinetes de transferĂŞncia tecnolĂłgica, incubadoras, centros de empreendedorismo ou a criação de fundos internos para estimular a aplicação de patentes, licenciamento e criação de spin-offs. A Universidade do Minho, um dos exemplos na regiĂŁo norte do paĂs, tem em funcionamento um laboratĂłrio de ideias de negĂłcio, designado por IdeaLab, que apoia a geração e o desenvolvimento de ideias de negĂłcio de base tecnolĂłgica e/ou conhecimento intensivo
Projected migrations of southern Indian Ocean albatrosses as a response to climate change
Anthropogenic climate change is altering the geographical distribution and regular movements of species. Highly-mobile pelagic seabirds, such as albatrosses, are particularly threatened by human activities, such as fisheries bycatch. Predicting the impact of climate change on how these animals roam the ocean is an important step towards making informed conservation decisions. In this study, we used a mechanistic model of migratory movements to predict how the migration of albatross species that breed in the southern Indian Ocean may change between now and the end of the century. The model is able to generate non-breeding movement patterns of albatrosses that correspond to empirical patterns from tracking data, thus providing confidence in the ability of the model to make future predictions. We projected the model using environmental conditions for 2100 based on a scenario assuming high emissions (IPCC RCP 8.5). Overall, we found very little projected change in the non-breeding distribution of albatrosses compared to the present. Some change, however, is predicted for large albatrosses, which, due to their size, are more affected by wind, and are projected to migrate further eastwards in the future scenario. These results contrast with previous analyses focusing on the breeding distribution that used statistical modelling, such as habitat and species distributions models, and predicted poleward shifts in geographical distributions of various seabird species including albatrosses. Therefore, it highlights the need for formal comparison of predicted changes in distribution during different phases of the annual cycle of the albatrosses and/or integration of the different approaches. Our analysis also predicts that the overlap of albatrosses with Regional Fisheries Management Organisations (RFMOs) during the non-breeding season will remain similar in 2100 compared to today. This implies that large-scale by-catch mitigation measures implemented through fisheries management organisations will remain important over the next hundred years of climate changeinfo:eu-repo/semantics/publishedVersio
An ontogenetic perspective on migratory strategy of a long-lived pelagic seabird: Timings and destinations change progressively during maturation
The processes that drive the ontogeny of migratory strategies in long-lived animals with slow maturation remain enigmatic. While some short-lived migrants are known or believed to repeat the same migratory patterns throughout their lives, little is known on the time required for immature long-lived migrants to progressively acquire adult-like migratory behaviours, or which aspects take longer to refine during the maturation process. Here, we studied the ontogeny of long-distance migratory strategies and related patterns of spatial distribution in a long-lived seabird species during the annual cycle. To do so, we deployed light-level geolocators on 4- to 9-year-old immature Cory's shearwaters (Calonectris borealis) and on breeding adults. We revealed that migratory timings and destinations of young shearwaters progressively changed with age. The effect of ageing was remarkably evident on spring migratory performance and phenology. Birds gradually shortened the duration of the non-breeding period by advancing departure date and reducing travelling time, which resulted in a sequential arrival at the colony of the various age contingents. Ageing immatures gradually changed from a more exploratory strategy to a more conservative way of exploiting resources, reducing both their year-round spatial spread across oceanic domains and the total distance travelled. Immatures always performed a trans-equatorial migration to the Southern Hemisphere, contrasting with 17% of the adults which remained in the North Atlantic year-round. Finally, during the breeding season immatures were widely dispersed through the North Atlantic reducing their overlap with breeding adults. Our long-term study provides empirical support to the hypothesis that in long-lived species, the refinement of migratory behaviour and year-round spatial distribution is a progressive process mediated by age and experience, where life stage constraints and competition for resources may also play a role. The emerging pattern suggests that for some avian taxa, the ontogeny of migratory strategy is a prolonged, complex and dynamic process.FEDER; FCT-Fundação para a Ciência e Tecnologiainfo:eu-repo/semantics/publishedVersio
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