NADH oxidase activity of rat and human liver xanthine oxidoreductase: potential role in superoxide production

J Biol Inorg Chem (2007) 12:777–787 DOI 10.1007/s00775-007-0229-7

Dimensions of source credibility in the case of user-generated advertisements

A Work Project, presented as part of the requirements for the Award of a Masters Degree in Management from the NOVA – School of Business and Economics

The integration of online advertising: The effects of source expertise and certainty level of the message on consumer involvement and persuasion in the context of user-generated advertising

A Work Project, presented as part of the requirements for the Award of a Masters Degree in Management from the NOVA – School of Business and Economics

Dependence of IVIM-DWI estimations on acquisition parameters

Dissertação para obtenção do Grau de Mestre em Engenharia Biomédica

Compact ion-source based on superionic rubidium silver iodide (RbAg4I5) solid electrolyte

Dissertação para obtenção do Grau de Mestre em Engenharia Física

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

Implementação de uma solução open source de Business Intelligence com metodologia Ágil

A importância dos sistemas de data warehousing e business intelligence é cada vez mais pronunciada, no sentido de dotar as organizações com a capacidade de guardar, explorar e produzir informação de valor acrescido para os seus processos de tomada de decisão. Esta realidade é claramente aplicável aos sectores da administração pública portuguesa e, muito em particular, aos organismos com responsabilidades centrais no Ministério da Saúde. No caso dos Serviços Partilhados do Ministério da Saúde (SPMS), que tem como missão prover o SNS de sistemas centrais de business intelligence, o apelo dos seus clientes, para que possam contar com capacidades analíticas nos seus sistemas centrais, tem sido sentido de forma muito acentuada. Todavia, é notório que, tanto os custos, como a complexidade, de grande parte destes projetos têm representado uma séria ameaça à sua adoção e sucesso. Por um lado, a administração pública tem recebido um forte encorajamento para integrar e adotar soluções de natureza open source (modelo de licenciamento gratuito), para os seus projetos de sistemas de informação. Por outro lado, temos vindo a assistir a uma vaga de aceitação generalizada de novas metodologias de desenvolvimento de projetos informáticos, nomeadamente no que diz respeito às metodologias Agéis, que se assumem como mais flexíveis, menos formais e com maior grau de sucesso. No sentido de averiguar da aplicabilidade do open source e das metodologias Ágeis aos sistemas de business intelligence, este trabalho documenta a implementação de um projeto organizacional para a SPMS, com recurso a ferramentas open source de licenciamento gratuito e através de uma metodologia de desenvolvimento de natureza Ágil.

Aquaponics and its potential aquaculture wastewater treatment and human urine treatment

The main objective of this thesis is to study the developing fields of aquaponics and its potential for aquaculture wastewater treatment and human urine treatment. Aquaponics is a food production system which combines fish farming (aquaculture) with soilless crop farming (hydroponics). In this thesis the concept of aquaponics and the underlying processes are explained. Research on aquaculture wastewater and human urine wastewater is reviewed and its potential application with aquaponic systems is studied. An overview of the different types of aquaponic systems and current research on the field is also presented. A case study was conducted in a farm in Askeröd, Sweden, which involved building two aquaponic systems (System 1 and System 2) and a human urine-based aquaponic system (System 3), with different degrees of component complexity and sizes. The design, building and monitoring of System 1, System 2 and System 3 was documented and described in detail. Four day experiments were conducted which tested the evolution in concentration of Total Ammonia Nitrogen (NH4+/NH3), Nitrite (NO2-), Nitrate (NO3-), Phosphate (PO43-), and Dissolved Oxygen (O2) after an initial nutrient input. The goal was to assess the concentrations of these parameters after four days and compare them with relevant literature examples in the aquaculture industry and in source-separated urine research. Neither of the two aquaponic systems (System 1 and System 2) displayed all of the parameter concentrations in the last day of testing below reference values found in literature. The best performing of the aquaponic systems was the more complex system (System 2) combining the hydroponic Nutrient Film Technique with a Deep Water Culture component, with a Total Ammonia Nitrogen concentration of 0,20 mg/L, a Nitrite concentration of 0,05 mg/L, a Nitrate concentration of 1,00-5,00 mg/L, a Phosphate concentration of <0,02 mg/L and a Dissolved Oxygen concentration of 8,00 mg/L. The human urine-based aquaponic system (System 3) underperformed in achieving the reference concentration values in literature for most parameters. The removal percentage between the higher recorded values after the input addition and the final day of testing was calculated for two literature examples of separated urine treatment and System 3. The system had a removal percentage of 75% for Total Ammonia Nitrogen, 98% for Nitrite, 25% for Nitrate and 50% for Phosphate. These percentages still underperformed literature examples in most of the tested parameters. The results gathered allowed to conclude that while aquaculture wastewater treatment and human urine treatment is possible with aquaponics systems, overall these did not perform as well as some examples found in recirculating aquaculture systems and source-separated urine treatment literature. However, better measuring techniques, longer testing periods and more research is recommended in this field in order to draw an improved representative conclusion.

Application of NMR RDC’s, relaxation and self-diffusion for the study of dynamic processes of small molecules in solution

Spin-lattice Relaxation, self-Diffusion coefficients and Residual Dipolar Couplings (RDC’s) are the basis of well established Nuclear Magnetic Resonance techniques for the physicochemical study of small molecules (typically organic compounds and natural products with MW < 1000 Da), as they proved to be a powerful and complementary source of information about structural dynamic processes in solution. The work developed in this thesis consists in the application of the earlier-mentioned NMR techniques to explore, analyze and systematize patterns of the molecular dynamic behavior of selected small molecules in particular experimental conditions. Two systems were chosen to investigate molecular dynamic behavior by these techniques: the dynamics of ion-pair formation and ion interaction in ionic liquids (IL) and the dynamics of molecular reorientation when molecules are placed in oriented phases (alignment media). The application of NMR spin-lattice relaxation and self-diffusion measurements was applied to study the rotational and translational molecular dynamics of the IL: 1-butyl-3-methylimidazolium tetrafluoroborate [BMIM][BF4]. The study of the cation-anion dynamics in neat and IL-water mixtures was systematically investigated by a combination of multinuclear NMR relaxation techniques with diffusion data (using by H1, C13 and F19 NMR spectroscopy). Spin-lattice relaxation time (T1), self-diffusion coefficients and nuclear Overhauser effect experiments were combined to determine the conditions that favor the formation of long lived [BMIM][BF4] ion-pairs in water. For this purpose and using the self-diffusion coefficients of cation and anion as a probe, different IL-water compositions were screened (from neat IL to infinite dilution) to find the conditions where both cation and anion present equal diffusion coefficients (8% water fraction at 25 ºC). This condition as well as the neat IL and the infinite dilution were then further studied by 13C NMR relaxation in order to determine correlation times (c) for the molecular reorientational motion using a mathematical iterative procedure and experimental data obtained in a temperature range between 273 and 353 K. The behavior of self-diffusion and relaxation data obtained in our experiments point at the combining parameters of molar fraction 8 % and temperature 298 K as the most favorable condition for the formation of long lived ion-pairs. When molecules are subjected to soft anisotropic motion by being placed in some special media, Residual Dipolar Couplings (RDCs), can be measured, because of the partial alignment induced by this media. RDCs are emerging as a powerful routine tool employed in conformational analysis, as it complements and even outperforms the approaches based on the classical NMR NOE or J3 couplings. In this work, three different alignment media have been characterized and evaluated in terms of integrity using 2H and 1H 1D-NMR spectroscopy, namely the stretched and compressed gel PMMA, and the lyotropic liquid crystals CpCl/n-hexanol/brine and cromolyn/water. The influence that different media and degrees of alignment have on the dynamic properties of several molecules was explored. Different sized sugars were used and their self-diffusion was determined as well as conformation features using RDCs. The results obtained indicate that no influence is felt by the small molecules diffusion and conformational features studied within the alignment degree range studied, which was the 3, 5 and 6 % CpCl/n-hexanol/brine for diffusion, and 5 and 7.5 % CpCl/n-hexanol/brine for conformation. It was also possible to determine that the small molecules diffusion verified in the alignment media presented close values to the ones observed in water, reinforcing the idea of no conditioning of molecular properties in such media.

The effect of key process operational conditions on enhanced biological phosphorus removal from wastewater

Enhanced biological phosphorus removal (EBPR) is the most economic and sustainable option used in wastewater treatment plants (WWTPs) for phosphorus removal. In this process it is important to control the competition between polyphosphate accumulating organisms (PAOs) and glycogen accumulating organisms (GAOs), since EBPR deterioration or failure can be related with the proliferation of GAOs over PAOs. This thesis is focused on the effect of operational conditions (volatile fatty acid (VFA) composition, dissolved oxygen (DO) concentration and organic carbon loading) on PAO and GAO metabolism. The knowledge about the effect of these operational conditions on EBPR metabolism is very important, since they represent key factors that impact WWTPs performance and sustainability. Substrate competition between the anaerobic uptake of acetate and propionate (the main VFAs present in WWTPs) was shown in this work to be a relevant factor affecting PAO metabolism, and a metabolic model was developed that successfully describes this effect. Interestingly, the aerobic metabolism of PAOs was not affected by different VFA compositions, since the aerobic kinetic parameters for phosphorus uptake, polyhydroxyalkanoates (PHAs) degradation and glycogen production were relatively independent of acetate or propionate concentration. This is very relevant for WWTPs, since it will simplify the calibration procedure for metabolic models, facilitating their use for full-scale systems. The DO concentration and aerobic hydraulic retention time (HRT) affected the PAO-GAO competition, where low DO levels or lower aerobic HRT was more favourable for PAOs than GAOs. Indeed, the oxygen affinity coefficient was significantly higher for GAOs than PAOs, showing that PAOs were far superior at scavenging for the often limited oxygen levels in WWTPs. The operation of WWTPs with low aeration is of high importance for full-scale systems, since it decreases the energetic costs and can potentially improve WWTP sustainability. Extended periods of low organic carbon load, which are the most common conditions that exist in full-scale WWTPs, also had an impact on PAO and GAO activity. GAOs exhibited a substantially higher biomass decay rate as compared to PAOs under these conditions, which revealed a higher survival capacity for PAOs, representing an advantage for PAOs in EBPR processes. This superior survival capacity of PAOs under conditions more closely resembling a full-scale environment was linked with their ability to maintain a residual level of PHA reserves for longer than GAOs, providing them with an effective energy source for aerobic maintenance processes. Overall, this work shows that each of these key operational conditions play an important role in the PAO-GAO competition and should be considered in WWTP models in order to improve EBPR processes.

Towards printed carbon nanotube transistors on paper substrates

This thesis reports the work performed in the optimization of deposition parameters of Multi – Walled Carbon Nanotubes (MWCNT) targeting the development of a Field Effect Transistors (FET) on paper substrates. The CNTs were dispersed in a water solution with sodium dodecyl sulphate (SDS) through ultrasonication, ultrasonic bath and a centrifugation to remove the supernatant and have a homogeneous solution. Several deposition tests were performed using different types of CNTs, dis-persants, papers substrates and deposition techniques, such as spray coating and inkjet printing. The characterization of CNTs was made by Scanning Electron Microscopy (SEM) and Hall Effect. The most suitable CNT coatings able to be used as semiconductor in FETs were deposited by spray coat-ing on a paper substrate with hydrophilic nanoporous surface (FS2) at 100 ºC, 4 bar, 10 cm height, 5 second of deposition time and 90 seconds of drying between steps (4 layers of CNTs were deposited). Planar electrolyte gated FETs were produced with these layers using gold-nickel gate, source and drain electrodes. Despite the small current modulation (Ion/Ioff ratio of 1.8) one of these devices have p-type conduction with a field effect mobility of 1.07 cm2/V.s.

Bioremediation and CO2 scavenging using molybdenum-containing enzymes

Carbon dioxide valorization, will not only help to relieve the greenhouse effect but might also allow us to transform it in value-added chemicals that will help overcoming the energy crisis. To accomplish this goal, more research that focus on sequestering CO2 and endeavors through a carbon-neutral or carbon-negative strategy is needed in order to handle with the dwindling fossil fuel supplies and their environmental impact. Formate dehydrogenases are a promising means of turning CO2 into a biofuel that will allow for a reduction of greenhouse gas emissions and for a significant change to the economic paramount. The main objective of this work was to assess whether a NAD+-independent molybdenum-containing formate dehydrogenase is able to catalyze the reduction of CO2 to formate. To achieve this, a molybdenum-containing formate dehydrogenase was isolated from the sulfate reducing bacteria Desulfovibrio desulfuricans ATCC 27774. Growth conditions were found that allowed for a greater cellular mass recovery and formate dehydrogenase expression. After growth trials, kinetic assays for formate oxidation and CO2 reduction were performed and kinetic parameters determined. For the formate oxidation reaction, a KM of 49 μM and a turnover constant of 146 s-1 were determined. These kinetic parameters are in agreement with those determined by Mota, et al. (2011). Finally, we found that this molybdenum-containing enzyme was able to catalyze the reduction of CO2 to formate with a turnover constant of 4.6 s-1 and a KM of 13 μM. For the first time a NAD+-independent molybdenum-containing formate dehydrogenase was found to catalyze CO2 reduction, allowing its use as a biocatalyst in energetically efficient CO2 fixation processes that can be directed towards bioremediation or as an alternative and renewable energy source. Characterizing these enzymes may lead to the development of more efficient synthetic catalysts, make them readily available and more suited for practical applications.

Study of salt stress tolerance in spelt

World population is increasing at an alarming rate while food productivity is decreasing due to the effect of various abiotic stresses. Soil salinity is one of the most important abiotic stress and a limiting factor for worldwide plant production. In addition to its important effects on yield, salt stress affects numerous cellular activities, including cell wall composition, photosynthesis, protein synthesis, ions and organic solutes. Up to 20% of the irrigated arable land in arid and semiarid regions is already salt affected and is still expanding. Improving salt tolerant varieties is of major importance, and efforts should be focused on finding adaptive mechanisms which are involved in salinity tolerance. In this study, several spelt wheat (Triticum aestivum var. Spelta) genotypes and one cultivar of modern bread wheat were used to screen them for salt tolerance. Spelt is an old-European cereal crop currently attracting renewed interest as a food grain because it is said to be harder than wheat and requires less fertilizer. Spelt wheat is also becoming very attractive genetic source by plant breeders due to its wide adaptation ability to various stressful conditions such as soil salinity. In this study morphological parameters (e.g., leaf appearance; shoot elongation), dry matter production, mineral nutrients (especially Na and K), and activity of antioxidative enzymes were measured to select superior genotypes of spelt for salt tolerance. The results showed that Spelt genotype Sp41 is a salt sensitive genotype and genotypes Sp69, Sp96 and Sp912 are good candidates for salt tolerant genotypes.

Modulation of electrical stimulation applied to human physiology and clinical diagnostic

The use, manipulation and application of electrical currents, as a controlled interference mechanism in the human body system, is currently a strong source of motivation to researchers in areas such as clinical, sports, neuroscience, amongst others. In electrical stimulation (ES), the current applied to tissue is traditionally controlled concerning stimulation amplitude, frequency and pulse-width. The main drawbacks of the transcutaneous ES are the rapid fatigue induction and the high discomfort induced by the non-selective activation of nervous fibers. There are, however, electrophysiological parameters whose response, like the response to different stimulation waveforms, polarity or a personalized charge control, is still unknown. The study of the following questions is of great importance: What is the physiological effect of the electric pulse parametrization concerning charge, waveform and polarity? Does the effect change with the clinical condition of the subjects? The parametrization influence on muscle recruitment can retard fatigue onset? Can parametrization enable fiber selectivity, optimizing the motor fibers recruitment rather than the nervous fibers, reducing contraction discomfort? Current hardware solutions lack flexibility at the level of stimulation control and physiological response assessment. To answer these questions, a miniaturized, portable and wireless controlled device with ES functions and full integration with a generic biosignals acquisition platform has been created. Hardware was also developed to provide complete freedom for controlling the applied current with respect to the waveform, polarity, frequency, amplitude, pulse-width and duration. The impact of the methodologies developed is successfully applied and evaluated in the contexts of fundamental electrophysiology, psycho-motor rehabilitation and neuromuscular disorders diagnosis. This PhD project was carried out in the Physics Department of Faculty of Sciences and Technology (FCT-UNL), in straight collaboration with PLUX - Wireless Biosignals S.A. company and co-funded by the Foundation for Science and Technology.

Sustainable urban planning: parameters to the operational process

In modern society, energy consumption and respect for the environment have become essential aspects of urban planning. The rising demand for alternative sources of energy, coupled with the decline in the construction sector and material usage, gives the idea that the thinking on modern cities, where attention is given to reduced energy consumption, savings, waste recycling and respect for the surrounding environment, is being put into practice. If we examine development of the city over recent centuries, by means of the theories of the most famous and influential urban planners, it is possible to identify the major problems caused by this type of planning. For this reason, in recent urban planning the use of systems of indicators that evaluate and certify land environmentally and energetically guides the master plan toward a more efficient city model. In addition the indicators are targeted on key factors determined by the commissioner or the opportunities the territory itself provides. Due the complexity of the environmental mechanics, the process of design and urban planning has become a challenging issue. The introduction of the indicators system has made it possible to register the life of the process, with a spiral route that allows the design itself to be refined. The aim of this study, built around the creation of a system of urban sustainability indicators that will evaluate highly eco-friendly cities, is to develop a certification system for cities or portions of them. The system will be upgradeable and objective, will employ real data and will be concerned with energy production and consumption.