Modelação da curva de potência no contexto da detecção de anomalias em turbinas eólicas

Atualmente é muito importante saber o estado de condição de uma máquina. Com o desenvolvimento da tecnologia e da complexidade desta, a dificuldade na verificação do estado de funcionamento também tem crescido. Consequentemente, a busca de novas ideias para resolver este problema tem aumentado. As turbinas eólicas são exemplos destas máquinas. Com o crescimento da preocupação com as alterações climáticas, o seu uso tem aumentado consideravelmente. Em busca de novas maneiras de determinar a condição de funcionamento de uma turbina eólica sem interromper o seu funcionamento surgiu o tema deste trabalho que tem como objetivo a monitorização do estado de condição de uma turbina através da sua curva de potência. Este trabalho tem base em técnicas que se enquadram no âmbito da inteligência computacional. Para tal, será feita uma análise semanal onde a curva de potência de uma dada semana será comparada com a curva de potência estimada por um modelo de regressão criado ou ajustado com os dados previamente observados em períodos classificados como sendo representativos de bom estado de funcionamento. Algumas tentativas serão realizadas para tentar aperfeiçoar o modelo com o intuito de obter melhores resultados no final. Serão ainda testados diferentes blocos de dados de treino para verificar qual o melhor conjunto de variáveis de treino para ser usado pelo programa com o intuito de avaliar o estado de condição do equipamento. No final, foi possível identificar anomalias a partir da diferença das curvas de potência e justificar as diferenças com base na forma da curva ou com o número de observações nos blocos de dados usados na previsão

Synergistic Activity of Cymbopogon citratus and Mentha piperita Essential Oils against the Pinewood Nematode

The pinewood nematode (PWN) Bursaphelenchus xylophilus is a major threat to pine forests. Research on sustainable pest management strategies is now a priority. Essential oils (EOs) are biodegradable, complex mixtures of volatiles that can show low toxicity to mammals and powerful nematicidal activities depending on their chemical composition. In the present work, the EOs of four plants were screened against the PWN, solely and in combination to identify possible synergistic interactions. The combination of Cymbopogon citratus and Mentha piperita EOs (1:1) resulted in higher activities than those of each tested solely, suggesting the occurrence of synergistic interactions between the compounds of these EOs. Research on the combination of synergistic EOs may lead to the development of plant based biopesticides with optimized activities against the PWN

First report on the synergistic interaction between essential oils against the pinewood nematode Bursaphelenchus xylophilus

Control of the pinewood nematode (PWN), the causal agent of pine wilt disease, can be achieved through the trunk injection of nematicides; however, many pesticides have been linked to environmental and human health concerns. Essential oils (EOs) are suitable alternatives due to their biodegradability and low toxicity to mammals. These complex mixtures of plant volatiles often display multiple biological activities and synergistic interactions between their compounds. The present work profiled the toxicity of eight EOs against the PWN in comparison to their 1:1 mixtures, to screen for successful synergistic interactions. Additionally, the main compounds of the most synergistic mixtures were characterized for their predicted environmental fate and toxicity to mammals in comparison to emamectin benzoate, a commercial nematicide used against PWN. The mixtures of Cymbopogon citratus with Mentha piperita and of Foeniculum vulgare with Satureja montana EOs showed the highest activities, with half-maximal effective concentrations (EC50) of 0.09 and 0.05 L/mL, respectively. For these, complete PWN mortality was reached after only ca. 15 min or 2 h of direct contact, respectively. Their major compounds had a higher predicted affinity to air and water environmental compartments and are reported to have very low toxicity to mammals, with low acute oral and dermal toxicities. In comparison, emamectin benzoate showed lower nematicidal activity, a higher affinity to the soil and sediments environmental compartments and higher reported oral and dermal toxicity to mammals. Overall, uncovering synergistic activities in combinations of EOs from plants of different families may prove to be a source of biopesticides with optimized toxicity against PWNs.info:eu-repo/semantics/publishedVersio

O nemátode da madeira do pinheiro: novas abordagens de controlo e monitorização

O nemátode da madeira do pinheiro é a maior ameaça para os povoamentos de pinheiro-bravo em Portugal. A investigação no INIAV aposta no desenvolvimento de novas estratégias de monitorização e biopesticidas para a sua contenção. O recurso a compostos naturais e a organismos antagonistas é o alvo de estudo de vários projetos de investigação no INIAV, por poder vir a ser uma estratégia de luta inovadora e um importante contributo nos atuais meios de controlo deste organismo

A relação das famílias com a escola : um olhar sobre a escolha da escola secundária : um estudo de caso

Tese de mestrado em Ciências da Educação (Área de especialização em Administração Educacional), apresentada à Universidade de Lisboa, através da Faculdade de Psicologia e de Ciências da Educação, 2006Com relevo para as duas últimas décadas do século XX, a crise do Estado Providência, a emergência de políticas neo-liberais e, a globalização da economia, entre outros fenómenos, tem levado ao despontar de novas formas de regulação do sistema educativo, com destaque para lógica da regulação mercantil. Neste estudo propomo-nos a perceber a forma como os EE se relacionam com a Escola, e se as suas práticas corroboram a lógica da regulação mercantil. A primeira parte deste trabalho, é constituída pelo enquadramento teórico, onde é feito um percurso sintético pelas tendências que a nível internacional e em Portugal, têm marcado a evolução das políticas educativas que conduziram ao reforço da presença dos pais nos órgãos da escola e, à implementação de medidas conducentes à livre escolha de escola. A segunda parte é relativa ao dispositivo empírico montado para a consecução desta investigação e que usou como recursos o inquérito por questionário, bem como ferramentas da estatística descritiva e da inferência estatística disponíveis no programa informático SPSS. Os resultados levam-nos a concluir que relativamente às formas de participação legalmente instituídas, o envolvimento dos EE é pautado por uma certa passividade. No entanto, no que diz respeito ao envolvimento dos EE ao longo do processo educativo dos seus educandos, é nítido o seu envolvimento na valorização dos saberes da Escola e no apoio e incentivo na obtenção de um certificado escolar. Por outro lado, esta participação informal também é patente na forma como os EE procedem à escolha da escola secundária, levando-nos a perceber a existência de processos informais de livre escolha de escola.Dans les dernières décennies du vingtième siècle, la crise de L ’État de Providence, l’émergence de politiques néo-libérales et la globalisation de l’économie, entre autres phénomènes a provoqué la création de nouvelles formes de régulation du système éducatif, en donnant plus importance à la logique de la régulation mercantile. Dans cette étude nous voulons comprendre la façon dont les parents font des connaissances avec L ’École, et si leurs pratiques soutiennent la logique de la régulation mercantile. La première partie de cette étude, a l’encadrement théorique, où on fait un parcours tout à fait résumé par les tendances qui, au niveau international et au Portugal aussi, ont marqué l’évolution des politiques éducatives qui ont menées à l’augmentation de la présence des parents dans les organes représentatifs de l’école et a l’implémentation de mesures conduisant au choix libre d ’école. La seconde partie concernant de dispositif empirique pour la consécution de cette investigation et qui a utilisé comme recours l’enquête, aussi comme des outils de statistique descriptive et l’inférence statistique disponibles dans un programme informatique le SPSS. Les résultats nous ont mené à la conclusion que en ce qui concerne aux formes de participation légalement institutionnalisées, l’enveloppement des parents est caractérisé par une certaine passivité. Cependant l’enveloppement des parents tout au long du procès éducatif de leurs enfants, il est notable leur enveloppement dans la valorisation des savoirs de L ’École et l’appui et incitation dans l'obtention d ’un certificat de l’école. D ’un autre côté, cette participation informelle est aussi présente dans la façon dont les parents choisissent l’école secondaire, en nous menant à comprendre l’existence de phénomènes informels du choix libre d ’école.With special emphasis to the last two decades of the twentieth century the crisis of the Welfare State, the appearing of neo-liberal policies and the globalization of the economy among other phenomena, has lead to the rise of new ways of regulating the educational system, focusing mostly on the logic of the mercantile regulation. With this study we want to understand the way parents put themselves in connection with school and if the ways they behave support the logic of the mercantile regulation. The first part of this study deals with the theoretical setting where we make a birds eye view of the tendencies that have marked the evolution of educational policies, both at an international level and in Portugal, and which have lead to the reinforcement of the presence of parents in the school departments and to the implementation of measures leading to the free school choice. The second part is related to the empiric work set for the consecution of this study and which used as resources not only the survey but also tools on the field of descriptive statistics and statistic inference available in SPSS. The results help us come to the conclusion that with regard to the ways of participation legally instituted, parents’ involvement is characterised by some passivity. However, regarding those parents’ involvement throughout the educational process of their children their involvement in the importance of the knowledge provided by the school is quite obvious. The same applies to their support and contribution to their children’s final school diploma. On the other hand, this informal collaboration can also be seen in the ways parents choose the secondary school they want their children to attend, which enable us to detect informal phenomena behind the free school choice

A Cytogenomic Analysis Reveals a New <i>Fusarium fujikuroi</i> Species Associated with Lemongrass (<i>Cymbopogon citratus</i>)

This study presents the first report of a Fusarium wilt in Cymbopogon citratus in Portugal. Fusarium is one of the most prominent genera of plant pathogens due to its wide range of hosts and mycotoxin production. The Fusarium fujikuroi species complex (FFSC) encompasses several threatening known plant pathogens. Cymbopogon citratus is a broadly distributed aromatic and medicinal plant rich in bioactive volatiles, which are relevant to several industries. The primary goal of this study was to identify and characterize the Fusarium fujikuroi species putatively responsible for the observed wilt. This report displays symptomatologic, cultural, morphologic, genetic, and cytogenomic characteristics associated with this fungus and disease. The cultural features included flat, white-colored colonies with filiform margins. Additionally, these colonies displayed abundant cottony aerial mycelia at the upper surface and orange-violet color at the lower surface. On Carnation Leaf-Piece Agar, septate fusoid macroconidia were present, displaying a flattened tapering toward the basal part and a number of septa ranging from one to four. The comparison between the amplified and aligned ITS sequences revealed 100% similarity between the isolate and the FFSC. Finally, a flow cytometry assay revealed an estimated genome size of 29.9 Mbp. This finding contrasts with other known pathogens from the Fusarium fujikuroi species complex. Ultimately, novel pathogens might be uncovered by exploring the mycobiome of diseased Cymbopogon citratus plants

Grassland Crops as Drivers for the Improvement of Soil Fertility

Managing soil fertility is vital for agriculture. However, modern farming excessively relies on mineral fertilizers, which lessens profit and endangers ecosystem health. Grasslands made up of Poaceae and Fabaceae, including woody species, offer feed for livestock, lowers farmers’ economic risks, and conserve resources. Grassland crops can enhance soil fertility in a more sustainable way than mineral fertilization. To counter fertilizer-driven soil decline, permanent grasslands or crop rotations are effective. Also, grassland soils generally contain more nitrogen, potassium and organic matter and less phosphorus than cropland soils. They additionally enhance soil’s physical and biological parameters, limiting erosion while elevating biodiversity. This work focuses on the benefits of grasslands towards crop production, reviewing their influence on soil fertility parameters that boost soil health

Essential Oil Volatiles as Sustainable Antagonists for the Root-Knot Nematode Meloidogyne ethiopica

Climate change is prompting a shift of tropical pests to locations with a previously lower probability of invasion. This is the case for root-knot nematodes, Meloidogyne sp., particularly of the tropical group. Among them, M. ethiopica is now considered a threat to European food security. The development of novel sustainable nematicides can be based on in vitro bioassays of highly active phytochemicals, e.g., volatiles from essential oils. However, a steady supply of nematodes is often very difficult and dependent on environmental conditions. In the present study, an in vitro co-culture system of M. ethiopica parasitizing hairy roots of Solanum lycopersicum was established, for the first time, to easily obtain populations of second-stage juveniles (J2). These were then used to screen the nematicidal activity of 10 volatile compounds characteristic of essential oils. Finally, information on the most successful compounds was reviewed to predict their environmental dispersion and ecotoxicological hazards. The M. ethiopica population obtained from the co-culture was morphologically similar to reported populations in natural conditions and could be accurately used in direct-contact bioassays. The aldehydes citral and citronellal induced complete mortality of the tested J2, at 1 mg/mL, while compounds from other chemical groups were not as successful. In comparison to commonly used commercial nematicides, citral and citronellal were less likely to accumulate in the water environmental compartment and have lower reported toxicities compared to aquatic organisms and to mammals. Overall, in vitro co-cultures showed the potential to expedite the screening and discovery of bioactive compounds as a contribution to the development of sustainable biopesticides, as well as to lower the impacts of modern farming on agroecosystems

Pre-diabetes alters testicular PGC1-α/SIRT3 axis modulating mitochondrial bioenergetics and oxidative stress

Pre-diabetes, a risk factor for type 2 diabetes development, leads to metabolic changes at testicular level. Peroxisome proliferator-activated receptor γ coactivator 1α(PGC-1α) and Sirtuin 3 (Sirt3) are pivotal inmitochondrial function. We hypothesized that pre-diabetes disrupts testicular PGC-1α/Sirt3 axis, compromising testicular mitochondrial function. Using a high-energy-diet induced pre-diabetic rat model, we evaluated testicular levels of PGC-1α and its downstream targets, nuclear respiratory factors 1 (NRF-1) and 2 (NRF-2),mitochondrial transcription factor A (TFAM) and Sirt3.We also assessedmitochondrial DNA (mtDNA) content, mitochondrial function, energy levels and oxidative stress parameters. Protein levels were quantified by Western Blot, mtDNA contentwas determined by qPCR.Mitochondrial complex activity and oxidative stress parameterswere spectrophotometrically evaluated. Adenine nucleotide levels, adenosine and its metabolites (inosine and hypoxanthine) were determined by reverse-phase HPLC. Pre-diabetic rats showed increased blood glucose levels and impaired glucose tolerance. Both testicular PGC-1α and Sirt3 levels were decreased. NRF-1, NRF-2 and TFAM were not altered. Testicular mtDNA content was decreased. Mitochondrial complex I activity was increased, whereas mitochondrial complex III activity was decreased. Adenylate energy charge was decreased in pre-diabetic rats, as were ATP and ADP levels. Conversely, AMP levels were increased, evidencing a decreased ATP/AMP ratio. Concerning to oxidative stress pre-diabetes decreased testicular antioxidant capacity and increased lipid and protein oxidation. In sum, pre-diabetes compromises testicular mitochondrial function by repressing PGC-1α/Sirt3 axis and mtDNA copy number, declining respiratory capacity and increasing oxidative stress. This study gives newinsights into overall testicular bioenergetics at this prodromal stage of disease.This work was supported by the Portuguese “Fundação para a Ciência e a Tecnologia”—FCT, co-funded by FEDER via Programa Operacional Factores de Competitividade—COMPETE/QREN (PTDC/ QUI-BIQ/121446/2010 and PEst-C/SAU/UI0709/2011). L. Rato (SFRH/ BD/72733/2010), A. I. Duarte (SFRH/BPD/26872/2006) and M. G. Alves (SFRH/BPD/80451/2011) were financed by FCT and European Social Fund. P. F. Oliveira was financed by FCT through FSE and POPH funds (Programa Ciência 2008)

Nematicidal Activity of Oxygen-Containing Aliphatic Compounds on <i>Bursaphelenchus xylophilus</i>, <i>B. mucronatus</i> and <i>B. fraudulentus</i>

The pinewood nematode (PWN), Bursaphelenchus xylophilus, the causal agent of pine-wilt disease (PWD), is a threat to Pinus forests in Asia and Europe. Bursaphelenchus mucronatus and B. fraudulentus are closely related non-pathogenic pine-wood nematodes. In the present work, four medium-chain aliphatic alcohols (C10 to C13) were evaluated in direct-contact bioassays against B. xylophilus, B. mucronatus and B. fraudulentus. The compounds showed high nematicidal activity against the species tested. The lowest values for half-maximal effective concentrations (EC50) were determined in B. xylophilus and B. fraudulentus, suggesting a higher sensibility to these compounds. Further bioassays will include compounds with different chain lengths and functional groups to explore the diversity in the activity of oxygen-containing aliphatic compounds for a more targeted sustainable-control strategy for the PWN