Optimal ecosystem management with structural dynamics

We address the problem of optimal management of a self organizing ecosystem along ecological succession. A dynamic carrying capacity is interpreted as depicting the dynamics of habitat creation and occupation along ecological succession. The ecosystem may have three growth modes: pure compensation (concave ecosystem regeneration function), depensation (convex-concave regeneration function) and critical depensation (additionally having negative growth rates for low biomass). We analyse the optimal policies for the management of the ecosystem for the three growth modes. Accordingly, we prove the existence of a Skiba points for certain types of ecosystems. Further, we compare usual golden rule paths with the derived optimal policies near the Skiba points.Ecosystem management; habitat creation; optimal policies; Skiba point

Welfare effects of green tax reforms in one sector and two sector dynamic economies

The main focus of this paper is twofold. First is to design Pigouvian taxes for different kinds of environmental external effects on the market economy in order to be possible to say what is the relevant information in each situation. Second is to address the question of the welfare effects of using close to Pigouvian taxes in real economies. This is done by considering more general conditions than those used by Aronsson et al. (2003). In particular, we take the ecosystem dynamics as being density dependent, and we assume that there are errors in measuring both the consumers marginal utility of nature and its regeneration rate. Additionally, we derive cost benefit rules for a green tax reform on the context of a two sector economy, in particular, a final goods sector and a knowledge sector, considering two externalities - one environmental externality and one technology externality.Environmental externalities; Non-Pigouvian taxes; social cost benefit analysis

Computational Results on Membership in R&D Cooperation Networks: To Be or Not To Be in a Research Joint Venture

In this study, we analyze firms’ membership in R&D (Research and Development) cooperation networks. Our main research hypothesis is that the membership in cooperation networks is related to the degree of the knowledge spillover. The approach focus on both cost symmetry and cost asymmetry. For that purpose, our work is developed in two tasks: we first develop an analytical model with three stages: in the first, firms decide whether to participate in a cooperative research network; in the second they simultaneously choose the level of R&D output, and finally firms choose the level of output through Cournot competition under both cost symmetry and cost asymmetry. Then we proceed with computational simulations in order to verify our hypothesis. From our results, we were able to conclude that cooperation leads to an improvement on RJV firms’ position in the market as it allows them to produce more than others with the same production conditions. Additionally, cooperating firms have to spend fewer resources on research, which turns the network a tremendous success on the productive efficiency level.R&D, networks, spillover, simulation, RJV

Nematoxic effect of essential oils and their fractions against the pinewood nematode, Bursaphelenchus xylophilus

The pinewood nematode (PWN) Bursaphelenchus xylophilus is a highly pathogenic plant parasite that greatly affects pine forests. In Portugal, the most affected species is Pinus pinaster Aiton. Despite great efforts, since its fist detection in 1999, the PWN has spread through the country, including Madeira Island, having been recently detected in Spain [1,2]. Containing this pest is of the utmost importance for European pine forest safeguard. Since most synthetic chemicals used to control phytoparasites are toxic to humans and animals, and can accumulate in the soil and in food plants [3], in the present work, the nematoxic potential of over 80 essential oils (EOs), isolated from the Portuguese flora, were assessed against the PWN. EOs were isolated by hydrodistillation and analysed by GC and GC-MS [3]. EOs hydrocarbon and oxygen-containing fractions were obtained as in [4]. Direct-contact assays, adapted from [3], were performed by adding EOs/methanol stock-solutions to 50-100 mixed-stage PWN suspensions. After 24h in darkness, dead and live nematodes were counted under an inverted microscope. Assays were repeated at least 10 times in two series. Mortalities ≥96% were obtained with 2μL/mL of the EOs isolated from Cymbopogon citratus, Eucalyptus citriodora, Mentha arvensis, Origanum virens, Origanum vulgare, Ruta graveolens, Satureja montana, Syzygium aromaticum, Thymbra capitata, Thymus caespititius (carvacrol and/or thymol-rich), Thymus vulgaris and Thymus zygis. These EOs were further tested at 1, 0.5 and 0.25μL/mL. Minimum lethal concentrations (LC100) <0.4μL/mL, were obtained for the 2-undecanone-rich R. graveolens EO and the carvacrol and γ-terpinene-rich S. montana and T. capitata EOs. Assays with EO fractions revealed that the monoterpene-rich nematoxic EOs control PWN through their combined hydrocarbon and oxygen-containing fractions through additive and/or synergic relations. As complex mixtures of active components, EOs may prove to be effective nematoxic age nts

Analysis of green net national product and genuine saving in Portugal, 1991 - 2005

The context of this paper is the measurement of welfare and weak sustainability, defined as non-declining utility, in dynamic economies, i.e., green, environmental or comprehensive accounting. We estimate the green net national product and genuine saving for Portugal 1991-2005, accounting for the disamenity of air pollution emissions, the depreciation of commercial forests - pine and eucalyptus -, the value of time (through technological progress), excluding the effect of business cycles and discussing the assumptions behind the usual terms included in the empirics of comprehensive accounting. For the accounting period considered we find that both GNNP and GS are positive, thereby indicating no sustainability problem in Portugal, although both GNNP and GS depict a trend towards unsustainability. Excluding technological progress there is a contradiction in the sustainability message: GS is negative after 2002, whereas GNNP is always positive, indicating that welfare increased.Welfare measures; green accounting; technological progress; business cycles

Correction of spatial distortion in magnetic resonance imaging

Dissertation to Obtain the Degree of Master in Biomedical EngineeringMagnetic Resonance Imaging (MRI) has been a major investigation and research focus among scientific and medical communities. So, new hardware with superior magnetic fields and faster sequences has been developed. However, these improvements result in intensity and spatial distortions, particularly in fast sequences, as Echo Plana Imaging (EPI), used in functional and diffusion-weighed MRI (fMRI and DW-MRI). Therefore, correction of spatial distortion is useful to obtain a higher quality in this kind of images. This project contains two major parts. The first part consists in simulating MRI data required for assessing the performance of Registration methods and optimizing parameters. To assess the methods five evaluation metrics were calculated between the corrected data and an undistorted EPI, namely: Root Mean Square (RMS); Normalized Mutual Information (NMI), Squared Correlation Coefficient(SCC); Euclidean Distance of Centres of Mass (CM) and Dice Coefficient of segmented images. In brief, this part validates the applied Registration correction method. The project’s second part includes correction of real images, obtained at a Clinical Partner. Real images are diffusion weighted MRI data with different b-values (gradient strength coefficient), allowing performance assessment of different methods on images with increasing b-values and decreasing SNR. The methods tested on real data were Registration, Field Map correction and a new proposed pipeline, which consists in performing a Field Map correction after a registration process. To assess the accuracy of these methods on real data, we used the same evaluation metrics, as for simulated data, except RMS and Dice Coefficient. At the end, it was concluded that Registration-based methods are better than Field Map, and that the new proposed pipeline produces some improvements in the registration. Regarding the influence of b-value on the correction, it is important to say that the methods performed using images with higher b’s showed more improvements in regarding metric values, but the behaviour is similar for all b-values

Control of the pinewood nematode Bursaphelenchus xylophilus by essential oils and extracts obtained from plants: a review.

The pinewood nematode (PWN), Bursaphelenchus xylophilus, is a serious threat to forest ecosystems at a global scale. The nematode has become a major quarantine problem due to its capability to completely destroy Pinus spp. trees, with great damage to the wood industry. Controlling the nematode inside a living tree is quite difficult, the techniques used being often ineffective and quite expensive. In the coming years, most chemicals used to control nematodes will be banned and replaced by safer and environmentally friendly products. As so, chemicals naturally produced by plants will play an important role in controlling diseases such as pine wilt. Plants, particularly aromatic ones, are commonly used due to the chemical properties of their secondary metabolites. Among these, essential oils and/or extracts are highly employed and are being tested as possible control of some organisms, like nematodes. Recent publications have evaluated essential oils derived from different plant species as natural nematicides [1; 2], antibacterial [3], anti-fungal [4] as well as insecticidal [5]. Concerning control of the PWN, a significant amount of information on plants tested, results obtained and employed techniques, is available. Our revision has extensively gathered this information, making it easier to search, read and use. It may become useful information for future studies on the subject, since it will be possible to check the plants already tested. Although numbers aren´t definitive, so far, tested plants are distributed amongst 148 families. The extracts or essential oils of plants belonging to the Asteraceae, Lamiaceae and Euphorbiaceae families show promising results on controlling the pinewood nematode

A Conversational Agent in mHealth for Self-Management of Parkinson’s Disease

Nos dias que correm vivemos rodeados de tecnologia, onde os “smartphones” preenchem um espaço muito importante nas nossas vidas. O uso de serviços móveis pelos “smartphones” no âmbito da saúde tem sido cada vez mais próspero, com um uso acessível por parte de todos. Com os avanços ao nível de inteligência artificial, especialmente no que toca à criação de sistemas inteligentes que comuniquem de forma natural com os humanos, torna-se possível criar agentes de conversação adequados para uma interação pessoa-máquina com distintos objetivos. Um dos objetivos que o projeto ONParkinson tem é o de aumentar a adesão terapêutica por parte das pessoas com doença de Parkinson. Sendo que a execução recorrente de exercício físico é essencial na gestão dos sintomas da doença de Parkinson. Por isso, existe a necessidade de interagir, educar e motivar os pacientes com doença de Parkinson para uma maior adesão aos exercícios terapêuticos. Este trabalho propõe uma solução, no âmbito do projeto ONParkinson, que envolve a criaçãao de um agente de conversação com unidades de conhecimento mais focadas nos exercicios terapêuticos e com unidades que visam motivar e manter a pessoa com doença de Parkinson motivada para a realização de exercícios terapêuticos. A avaliação da solução envolve fisioterapeutas e pessoas com doença de Parkinson. O plano de avaliação estabelece o estudo do desempenho técnico, da experiência do utilizador e da investigação na área da Saúde. Grande parte do conjunto dos pacientes com doença de Parkinson tem uma idade avançada, o que poderia levar a uma maior resistência ao uso das novas tecnologias. No entanto, os valores obtidos nos indicadores referentes à perspetiva de utilidade, facilidade de uso e satisfação da utilização demonstram um bom nível de usabilidade da solução proposta. Como a investigação de eficácia clínica ainda não foi conduzida, não é possível concluir a efiácia da solução proposta no aumento da adesão terapêutica por parte dos pacientes com doença de Parkinson.Nowadays, we live surrounded by technology, where smartphones fill a very important space in our lives. The use of mobile services by smartphones in the health sector has been increasingly prosperous, with accessible use by everyone. With advances in artificial intelligence methodologies, regarding the creation of intelligent systems that communicate naturally with humans, it is possible to create conversational agents for person-machine interaction with different objectives. One of the goals of the ONParkinson project is to increase therapeutic adherence by people with Parkinson’s disease. The recurrent execution of physical exercise is essential in the management of the symptoms of Parkinson’s disease. Therefore, there is a need to interact, educate and motivate patients with Parkinson’s disease for greater adherence to therapeutic exercises. This work proposes a solution, within the scope of the ONParkinson project, which involves the creation of a conversation agent with units of knowledge more focused on therapeutic exercises and with units aiming to motivate and keep the person with Parkinson’s disease motivated to perform therapeutic exercises. The evaluation of the solution involves physical therapists and patients with Parkinson’s disease. The evaluation plan establishes the study of technical performance, the study of user experience and Health research study. A large part of the set of patients with Parkinson’s disease is of advanced age, which could lead to greater resistance to the use of new technologies. However, the values obtained in the indicators referring to the perception of usefulness, ease of use and interaction satisfaction demonstrate a good level of usability of the proposed solution. As the investigation of clinical efficacy has not yet been conducted, it is not possible to conclude the effectiveness of the proposed solution in increasing therapeutic adherence by patients with Parkinson’s disease

Dendrimer-based Report-Eradication Antineoplasic Machines

Polyurea (PURE) dendrimers are a versatile platform for cancer nanotheranostics. The aim of this study was to improve the therapeutic efficacy of carboplatin by a buthionine sulfoximine (BSO) triggered inhibition of glutathione synthesis. BSO nanodelivery was achieved by controlled release from an encapsulated formulation using a folate target polyurea dendrimer of generation four (BSO@PUREG4-FA). Platinum-based anti-cancer drugs, such as cisplatin and carboplatin have been widely used in chemotherapy. In particular, carboplatins are used as standard chemotherapeutic in ovarian cancer, a silent killer, which is the most lethal gynecologic malignancy and the seventh most common cancer among women worldwide. However, carboplatin chemoresistance is a major problem and there is evidence that increased glutathione levels play an important role in the anticancer mechanism of action. Cell death assays using OVCAR3 (OSC) and ES2 (OCCC) ovarian cancer cell lines were used to determine the efficacy of BSO@PUREG4-FA nanoformulations. Cytotoxicity data showed that the encapsulated drug, if compared with the free drug, improve the efficacy of BSO, by reduction of the IC50, against both OVCAR3 (64-fold) and ES2 (146-fold) cell lines. The results showed that inhibition of glutathione synthesis improve the efficacy of carboplatin in both cell lines. In this study a new method for detection of BSO was also developed, based on UV detection upon BSO chemical derivatization