Optimal choice between even- and uneven-aged forestry: the case of non-industrial private forest owners

An infinite-horizon discrete time model with multiple size-class structures using a transition matrix is built to assess optimal harvesting schedules in the context of Non-Industrial Private Forest (NIPF) owners. Three model specifications accounting for forest income, financial return on an asset and amenity valuations are considered. Numerical simulations suggest uneven-aged forest management where a rational forest owner adapts her or his forest policy by influencing the regeneration of trees or adjusting consumption dynamics depending on subjective time preference and market return rate dynamics on the financial asset. Moreover she or he does not value significantly non-market benefits captured by amenity valuations relatively to forest income.

The new economy: Essays in network economics and two-sided markets

Following the Introduction, which surveys existing literature on the technology advances and regulation in telecommunications and on two-sided markets, we address specific issues on the industries of the New Economy, featured by the existence of network effects. We seek to explore how each one of these industries work, identify potential market failures and find new solutions at the economic regulation level promoting social welfare. In Chapter 1 we analyze a regulatory issue on access prices and investments in the telecommunications market. The existing literature on access prices and investment has pointed out that networks underinvest under a regime of mandatory access provision with a fixed access price per end-user. We propose a new access pricing rule, the indexation approach, i.e., the access price, per end-user, that network i pays to network j is function of the investment levels set by both networks. We show that the indexation can enhance economic efficiency beyond what is achieved with a fixed access price. In particular, access price indexation can simultaneously induce lower retail prices and higher investment and social welfare as compared to a fixed access pricing or a regulatory holidays regime. Furthermore, we provide sufficient conditions under which the indexation can implement the socially optimal investment or the Ramsey solution, which would be impossible to obtain under fixed access pricing. Our results contradict the notion that investment efficiency must be sacrificed for gains in pricing efficiency. In Chapter 2 we investigate the effect of regulations that limit advertising airtime on advertising quality and on social welfare. We show, first, that advertising time regulation may reduce the average quality of advertising broadcast on TV networks. Second, an advertising cap may reduce media platforms and firms' profits, while the net effect on viewers (subscribers) welfare is ambiguous because the ad quality reduction resulting from a regulatory cap o¤sets the subscribers direct gain from watching fewer ads. We find that if subscribers are sufficiently sensitive to ad quality, i.e., the ad quality reduction outweighs the direct effect of the cap, a cap may reduce social welfare. The welfare results suggest that a regulatory authority that is trying to increase welfare via regulation of the volume of advertising on TV might necessitate to also regulate advertising quality or, if regulating quality proves impractical, take the effect of advertising quality into consideration. 3 In Chapter 3 we investigate the rules that govern Electronic Payment Networks (EPNs). In EPNs the No-Surcharge Rule (NSR) requires that merchants charge at most the same amount for a payment card transaction as for cash. In this chapter, we analyze a three- party model (consumers, merchants, and a proprietary EPN) with endogenous transaction volumes and heterogenous merchants' transactional benefits of accepting cards to assess the welfare impacts of the NSR. We show that, if merchants are local monopolists and the network externalities from merchants to cardholders are sufficiently strong, with the exception of the EPN, all agents will be worse o¤ with the NSR, and therefore the NSR is socially undesirable. The positive role of the NSR in terms of improvement of retail price efficiency for cardholders is also highlighted.

Fishing the key biological components of the bacterium Geobacter metallireducens for optimal biotechnological applications

Os resultados apresentados no capítulo 2 foram incluídos no artigo Dantas JM, Campelo LM, Duke NEC, Salgueiro CA, Pokkuluri PR (2015) "The structure of PccH from Geobacter sulfurreducens – a novel low reduction potential monoheme cytochrome essential for accepting electrons from an electrode", FEBS Journal, 282, 2215-2231.

Growth strategies in tourism entertainment industry - a pratical application-

In the past few years, prompted by the globalization and the quality and ease of travel, the world has witnessed a boom in the tourism sector. The forecast is that this tendency will continue in the upcoming years, representing a set of opportunities for companies operating in this business area. Boost Tourism operates in the tourism entertainment industry. Its revenues growth has been exponential so the founders decided that it was time to take it to new heights. This Work Project aims to study three alternative growth strategies and, based on a comprehensive analysis of the industry and the market, provide recommendations to outline the optimal expansion path.

Harvest control rule vs optimal harvesting of an age-structured population: The case of the Ibero-Atlantic Sardine Fishery

Research Masters

Establishing guidelines for obtaining optimal cell sources to use in tendon tissue engineering strategies

Cell-based approaches in tissue engineering (TE) have been barely explored for the treatment of tendon and ligament (T/L) tissues, requiring the establishment of a widely available cell source with tenogenic potential. As T/L cells are scarce, stem cells may provide a good alternative. Understanding how resident cells behave in vitro, might be useful for recapitulating the tenogenic potential of stem cells for tendon TE applications. Therefore, we propose to isolate and characterize human T/L-derived cells (hTDCs and hLDCs) and compare their regenerative potential with stem cells from adipose tissue (hASCs) and amniotic fluid (hAFSCs)(1). T/L cells were isolated using different procedures and stem cells isolated as described elsewhere(1). Moreover, T/L cells were stimu- lated into the three mesenchymal lineages, using standard differentia- tion media. Cells were characterized for the typical stem cell markers as well as T/L related markers, namely tenascin-C, collagen I and III, decorin and scleraxis, using different complementary techniques such as real time RT-PCR, immunocytochemistry and flow cytometry. No differences were observed between T/L in gene expression and protein deposition. T/L cells were mostly positive for stem ness markers (CD73/CD90/CD105), and have the potential to differentiate towards osteogenesis, chondrogenesis and adipogenesis, demonstrated by the positive staining for AlizarinRed, SafraninO, ToluidineBlue and OilRed. hASCs and hAFSCs exhibit positive expression of all tenogenic mark- ers, although at lower levels than hTDCs and hLDCs. Nevertheless, stem cells availability is key factor in TE strategies, despite that it’s still required optimization to direct their tenogenic phenotype.

Cost optimal strategies for the renovation of residential neighbourhoods towards energy and emissions neutrality – Rainha Dona Leonor case study

Buildings are one of the major consumers of energy in Europe. This makes them an important target when aiming to reduce the energy consumptions and carbon emissions. The majority of the European building stock has already some decades and so it needs renovation in order to keep its functionality. Taking advantage of these interventions, the energy performance of the buildings may also be improved. In Portugal the renovation techniques, both regarding energy efficiency measures as well as measures for the use of renewable energy sources, are normally planned at the building scale. It is important to explore the possibility of having large scale interventions, has it has been done in other countries, namely at neighbourhood scale with district energy system in order to optimize the results in terms of costs and environmental impact.

Optimal behavior of responsive residential demand considering hybrid phase change materials

Due to communication and technology developments, residential consumers are enabled to participate in Demand Response Programs (DRPs), control their consumption and decrease their cost by using Household Energy Management (HEM) systems. On the other hand, capability of energy storage systems to improve the energy efficiency causes that employing Phase Change Materials (PCM) as thermal storage systems to be widely addressed in the building applications. In this paper, an operational model of HEM system considering the incorporation of more than one type of PCM in plastering mortars (hybrid PCM) is proposed not only to minimize the customerâ s cost in different DRPs but also to guaranty the habitantsâ  satisfaction. Moreover, the proposed model ensures the technical and economic limits of batteries and electrical appliances. Different case studies indicate that implementation of hybrid PCM in the buildings can meaningfully affect the operational pattern of HEM systems in different DRPs. The results reveal that the customerâ s electricity cost can be reduced up to 48% by utilizing the proposed model.

Stress-triggered synaptic malfunction: a gate along the path from depressionto dementia

Tese de Doutoramento em Ciências da Saúde.

A comparative analysis of primary stenting and optimal balloon coronary angioplasty in acute myocardial infarction. Six month results from the STENT PAMI trial

OBJECTIVE: To compare the outcome of balloon PTCA with final coronary stenosis diameter (SD) <=30%, with elective coronary stenting. METHODS: We performed a comparative analysis of the 6 month outcomes in patients treated with primary stenting and those who obtained an optimal balloon PTCA result treated during the first 12 hours of AMI onset included in the STENT PAMI randomized trial. RESULTS: The results were analysed into 3 groups: primary stenting (441 patients, SD=22±6%), optimal PTCA (245 patients), and nonoptimal PTCA (182 patients, SD= 37±5%). At the end of the 6 months primary stent group presented with the lowest restenosis(23 vs. 31 vs. 45%, p=0.001, respectively). Ischemia-driven target vessel revascularization rate (TVR) (7 vs. 15.5 vs. 19%, p=0.001, respectively). CONCLUSION: At the 6 month follow-up, primary stenting offered the lowest restenosis and ischemia-driven TVR rates. Compared to optimal balloon PTCA. Nonoptimal primary balloon PTCA pts (SD=31-50%), had the worst late angiographic outcomes and should be treated more actively with coronary stent implantation.

Construção de uma cultura de projeto numa comunidade de aprendizagem através do projeto curricular integrado

Dissertação de mestrado em Estudos da Criança (área de especialização em Integração Curricular e Inovação Educativa)

Optimal design in conjoint analysis

Magdeburg, Univ., Fak. für Mathematik, Diss., 2010

Optimal scheduling with uncertainty in the numerical data on the basis of a stability analysis

Scheduling, job shop, uncertainty, mixed (disjunctive) graph, stability analysis

Optimal operation of multiproduct batch plants

Multiproduct plants, Dynamic Optimization, Mixed Integer Linear/Non-Linear Programming, Scheduling

Optimal design for dose finding studies on safety and efficacy

Magdeburg, Univ., Fak. für Mathematik, Diss., 2009