Forest management in an urbanizing landscape

This paper aims at building a theoretical framework to examine the impact of development pressure on private owner’s forest management practices, namely, on regeneration and conversion cut dates. As the rent for developed land is rising over time, our model creates the possibility of switching from forestry to residential use at some point in the future, thus departing from the Faustmann’s traditional setup. Comparative statics results with respect to stumpage prices, regeneration costs and urban growth parameters are provided. The results obtained depend on the impact on the opportunity cost of holding the stand and the impact on the opportunity cost of holding the land, generalizing Faustmann’s unambiguous results.

TURISMO, CIDADES E PAISAGEM/TOURISM, CITIES AND LANDSCAPE

Os espaços públicos das cidades, sobretudo os daquelas para onde converge o turismo mundial, são sujeitos a múltiplos mecanismos de representação que os fragmentam e, em última análise, os reduzem a imagens idealizadas. Os autores dessas imagens, e dos seus sentidos, são muito diversificados, mas os profissionais ligados ao turismo (agências de viagem, revistas turísticas, documentaristas, etc.) e as instâncias públicas interessadas na divulgação turística das cidades (câmaras municipais, governos regionais, etc.) são, sem dúvida, duas das instâncias que mais operam no interior desses processos complexos de representação (e de mercadorização) do espaço das cidades. E se esses processos se associam hoje à relação feliz que milhões de pessoas estabelecem com as cidades no mundo inteiro, é no entanto necessário não esquecer que parte dessas paisagens são cuidadosamente construídas de forma, por um lado, a obliterar a lamentável realidade do urbanismo envolvente e, por outro, a delas excluir todos aqueles que inviabilizam a dinâmica cultural de construção de paisagens. We consider that the public spaces of cities, especially those which converge to the global tourism, are subject to multiple mechanisms of representation that fragment and, ultimately, reduce its idealized images. The authors of these images, and their senses are very diverse, but the professionals linked to tourism (travel agencies, tourist magazines, documentaries, etc.) and the government stakeholders interested in the dissemination of tourist cities (municipalities, regional governments, etc.) are undoubtedly two of the actors that operate within these more complex processes of representation of all urban space. And if these processes are associated today with the happy relationship that millions of people have with cities worldwide, it is however necessary not to forget that part of these landscapes are carefully constructed in a way, on one hand, to obliterate the unfortunate reality of the urban environment and, secondly, to delete all those that prevent the construction of dynamic cultural landscapes.

Going beyond duopoly: Connectivity breakdowns under receiving party pays

We show that the prediction of strategic connectivity breakdowns under a receiving-party-pays system and discrimination between on and off-net prices does not hold up once more than two mobile networks are considered. Indeed, if there are at least three competing networks and enough utility is obtained from receiving calls, only equilibria with finite call prices and receiving prices exist. Private negotiations over access charges then achieve the efficient outcome. Bill & keep (zero access charges) and free outgoing and incoming calls are efficient if and only marginal costs of calls are zero.

Landscape composition and climatic parameters significant in the spread of an invasive species (Pine wood Nematode)

Dissertação para obtenção do Grau de Mestre em Engenharia do Ambiente

Wind Power in the Portuguese Landscape: Global Concerns and Local Costs

Wind turbines and solar panels are becoming second nature in Portugal, as its occurrence in the country becomes ubiquitous. Somehow, one could argue that renewable energy in Portugal is in the process of ‘naturalisation’ as part of a new – mechanised, but environmentally benign – landscape. Portuguese Institute for the Conservation of Nature and Biodiversity (ICNB) has shown an ambiguous stance on this issue, defending global concerns towards renewable energy, while at the same time attempting to engage locals in the preservation of extensive ‘classified areas’. In the course of this research, we tried to focus on these incongruities and to analyse how they are impacting local communities during the process of wind power installation.

Structural connectivity based on diffusion Kurtosis imaging

Structural connectivity models based on Diffusion Tensor Imaging (DTI) are strongly affected by the technique’s inability to resolve crossing fibres, either intra- or inter-hemispherical connections. Several models have been proposed to address this issue, including an algorithm aiming to resolve crossing fibres which is based on Diffusion Kurtosis Imaging (DKI). This technique is clinically feasible, even when multi-band acquisitions are not available, and compatible with multi-shell acquisition schemes. DKI is an extension of DTI enabling the estimation of diffusion tensor and diffusion kurtosis metrics. In this study we compare the performance of DKI and DTI in performing structural brain connectivity. Six healthy subjects were recruited, aged between 25 and 35 (three females). The MRI experiments were performed using a 3T Siemens Trio with a 32-channel head coil. The scans included a T1-weighted sequence (1mm3), and a DWI with b-values 0, 1000 and 2000 s:mm