Sensitivity correction of images obtained with the prototype Clear-PEM in pre-clinical environment

Dissertation presented at Faculdade de Ciências e Tecnologia Universidade Nova de Lisboa to obtain a Master Degree in Biomedical Engineering

Constraint reasoning for differential models

The basic motivation of this work was the integration of biophysical models within the interval constraints framework for decision support. Comparing the major features of biophysical models with the expressive power of the existing interval constraints framework, it was clear that the most important inadequacy was related with the representation of differential equations. System dynamics is often modelled through differential equations but there was no way of expressing a differential equation as a constraint and integrate it within the constraints framework. Consequently, the goal of this work is focussed on the integration of ordinary differential equations within the interval constraints framework, which for this purpose is extended with the new formalism of Constraint Satisfaction Differential Problems. Such framework allows the specification of ordinary differential equations, together with related information, by means of constraints, and provides efficient propagation techniques for pruning the domains of their variables. This enabled the integration of all such information in a single constraint whose variables may subsequently be used in other constraints of the model. The specific method used for pruning its variable domains can then be combined with the pruning methods associated with the other constraints in an overall propagation algorithm for reducing the bounds of all model variables. The application of the constraint propagation algorithm for pruning the variable domains, that is, the enforcement of local-consistency, turned out to be insufficient to support decision in practical problems that include differential equations. The domain pruning achieved is not, in general, sufficient to allow safe decisions and the main reason derives from the non-linearity of the differential equations. Consequently, a complementary goal of this work proposes a new strong consistency criterion, Global Hull-consistency, particularly suited to decision support with differential models, by presenting an adequate trade-of between domain pruning and computational effort. Several alternative algorithms are proposed for enforcing Global Hull-consistency and, due to their complexity, an effort was made to provide implementations able to supply any-time pruning results. Since the consistency criterion is dependent on the existence of canonical solutions, it is proposed a local search approach that can be integrated with constraint propagation in continuous domains and, in particular, with the enforcing algorithms for anticipating the finding of canonical solutions. The last goal of this work is the validation of the approach as an important contribution for the integration of biophysical models within decision support. Consequently, a prototype application that integrated all the proposed extensions to the interval constraints framework is developed and used for solving problems in different biophysical domains.

Transport mechanism in ionic liquid membranes and the study of thiomersal biodegradation

The initial goal of this work was the development of a supported liquid membrane (SLM) bioreactor for the remediation of vaccine production effluents contaminated with a highly toxic organomercurial – thiomersal. Therefore, two main aspects were focused on: 1) the development of a stable supported liquid membrane – using room temperature ionic liquids (RTILs) – for the selective transport of thiomersal from the wastewater to a biological compartment, 2) study of the biodegradation kinetics of thiomersal to metallic mercury by a Pseudomonas putida strain. The first part of the work focused on the evaluation of the physicochemical properties of ionic liquids and on the SLMs’ operational stability. The results obtained showed that, although it is possible to obtain a SLM with a high stability, water possesses nonnegligible solubility in the RTILs studied. The formation of water clusters inside the hydrophobic ionic liquid was identified and found to regulate the transport of water and small ions. In practical terms, this meant that, although it was possible to transport thiomersal from the vaccine effluent to the biological compartment, complete isolation of the microbial culture could not be guaranteed and the membrane might ultimately be permeable to other species present in the aqueous vaccine wastewater. It was therefore decided not to operate the initially targeted integrated system but, instead, the biological system by itself. Additionally, attention was given to the development of a thorough understanding of the transport mechanisms involved in the solubilisation and transport of water through supported liquid membranes with RTILs as well as to the evaluation of the effect of water uptake by the SLM in the transport mechanisms of water-soluble solutes and its effect on SLM performance. The results obtained highlighted the determinant role played by water – solubilised inside the ionic liquids – on the transport mechanism. It became clear that the transport mechanism of water and water-soluble solutes through SLMs with [CnMIM][PF6] RTILs was regulated by the dynamics of water clusters inside the RTIL, rather than by molecular diffusion through the bulk of the ionic liquid. Although the stability tests vi performed showed that there were no significant losses of organic phase from the membrane pores, the formation of water clusters inside the ionic liquid, which constitute new, non-selective environments for solute transport, leads to a clear deterioration of SLM performance and selectivity. Nevertheless, electrical impedance spectroscopy characterisation of the SLMs showed that the formation of water clusters did not seem to have a detrimental effect on the SLMs’ electrical characteristics and highlighted the potential of using this type of membranes in electrochemical applications with low resistance requirements. The second part of the work studied the kinetics of thiomersal degradation by a pure culture of P. putida spi3 strain, in batch culture and using a synthe tic wastewater. A continuous ly stirred tank reactor fed with the synthetic wastewater was also operated and the bioreactor’s performance and robustness, when exposed to thiomersal shock loads, were evaluated. Finally, a bioreactor for the biological treatment of a real va ccine production effluent was set up and operated at different dilution rates. Thus it was possible to treat a real thiomersal-contaminated effluent, lowering the outlet mercury concentration to values below the European limit for mercury effluent discharges.

Les Plus Anciens Mastodontes Tetralophodontes (Langhien inférieur Vb), évolution et remarques sur la Tetralophodontie

This study deals with mastodont teeth found near Lisbon in Lower Langhian (lower Middle Miocene) fluviatile, feldspathic sands (Vb division). Conclusions are as follows: 1. Tetralophodont molars (even if at a still primitive stade of the tetralophodont condition) do exist at least since lower Langhian times, and not only since late Middle Miocene as was previously known. 2. Tri- and tetralophodont structures may (and indeed do) coexist in the same individual: such examples do not correspond to transitional forms, but instead to a mosaic of juxtaposed characters (however this does not mean there are no transitional forms in other instances). 3. So these structures coexisted in a population not yet genetically separated beyond fertile cross-breeding, i.e. beyond species' level. 4. Origin of the tetralophodont molar was due to some mutation (s). but without crossing species, limits and even more genus'ones. 5. At this times probably soon after the first appearance of tetralophodont mutants, animals with such characters were a small but significant minority among the population (17% if account is taken on D4's: only 2% after M2's). 6. There was not then any direct and clear correlation between number of lophs (transversal crests) and tooth size, even if the increase of such number goes along with length's increase. 7. Dimensions (length in special) in tetralophodont teeth tend to exceed those in «normal» trilophodont teeth, this being particularly clear in D4, even if there is no clear distinction: the situation is quite the same, maybe less marked, with the M2. 8. According to the preceding conclusions there are no reasons to segregate different taxa among such mastodont population on the grounds of the presence in D4, M1 and M2 of 3 or 4 crests (this character being regarded as diagnostic of the genus Tetralophodon). 9. On the contrary, if any natural (in biological sense) classification is disregarded and a morphological parataxonomy is adopted there should be considered both Gomphotherium angustidens and Tetralophodon sp.: however this is absolutely not our opinion.

Notas sobre depósitos de Taveiro estratigrafia, paleontologia, idade, paleoecologia

This paper reports some research work that has been done to support Geological Survey's field work for the 1:50.000 Carta Geológica de Portugal, (sheets 19-C Figueira da Foz and 19-D Coimbra-Lousã). Its main purpose was to establish the age of some continental formations. At Cerâmica do Mondego, Ld.ª near Taveiro, two series were observed. The lower one is mainly pelitic, montmorillonite being predominant. It also includes some sandy beds and channel deposits with high energy sediments (conglomerate with limestone pebbles). The upper series lies unconformably upon the former, and there is a neat discontinuity surface between the two. It mainly consists of sands, kaolinite being the most abundant of the clay minerals. This seems to indicate an intensive weathering, an acid, well drained environment and transportation by quite high energy running waters. No fossils were recorded. Preliminary paleontological results are presented, along with some data concerning other localities (Aveiro, etc.). Fossils found in the lower series are: gastropoda (Bulimus gaudryi, TV. 15 bed), several vertebrates (TV. 18), fishes (TV. 19?) and plants (TV. 19-TV. 24). Vertebrata belong to the same fauna as that from Vizo, Aveiro, etc. The presence of mammals is most important as only a single tooth was previously Know in Europe (Southern France) in Late Cretaceous formations. Elsewhere there are some mammalian remains in Peru besides the rich assemblages found in the USA and Mongolia. Plants are representative of the «Debeya flora» well known at several localities in Beira Litoral province, in «Buçaco sandstones», and in Lisbon's «Basaltic Complex». The most important stratigraphical conclusion is that the lower series is Upper Campanian and/or Maastrichtian in age, and not Tertiary as sometimes it has been considered. As at Aveiro, «Bebeya flora» occurs in-beds somewhat higher than those with the Aveiro-Vizo-Taveiro vertebrate fauna. Correlation with other «Debeya flora» localities are now more clear. Data concerning Taveiro lower series, in the whole, point out to a rather warm (and moist?) environment in an occasionally (seasonally?) flooded region.

Éssai de synthèse paléogéographique et paléobiostratigraphique du bassin occidental portugais au cours du crétacé supérieur

The Upper-Cretaceous transgressive serie is described by the authors, on the whole Occidental Portuguese Basin: it begins in the Lisbon region in the Albian and finishes in the Beira litoral province in the lower Turonian, while the sedimentation zones migrate Northward. The lithologic composition is given for each stage and sub-stage, taking into cgnsideration, in particular in the Upper Cenomanian, the lateral variations from one region to another. The paleogeography becomes clear by the study of the sedimentation environments (6 fig.). In conclusion, the authors propose a correlation between the whole serie and the accepted zonation of the Northwestern Europe. Tables show the repartition of the main macrofauna and microfauna.

Notes sur la géologie et la paleontology du Miocène de Lisbonne; (XX) les plus anciens mastodontes tetralophodontes (Langhien inférieur Vb), évolution et remarques sur la tetralophodontie

This study deals with mastodont teeth found near Lisbon in Lower Langhian (lower Middle Miocene) fluviatile, feldspathic sands (Vb division). Conclusions are as follows: 1. Tetralophodont molars (even if at a still primitive stade of the tetralophodont condition) do exist at least since lower Langhian times, and not only since late Middle Miocene as was previously known. 2. Tri- and tetralophodont structures may (and indeed do) coexist in the same individual: such examples do not correspond to transitional forms, but instead to a mosaic of juxtaposed characters (however this does not mean there are no transitional forms in other instances). 3. So these structures coexisted in a population not yet geneticaliy separated beyond fertile cross-breeding, i.e. beyond species'level. 4. Origin of the tetralophodont molar was due to some mutation (s). but without crossing species, limits and even more genus' ones. 5. At this times probably soon after the first appearance of tetralophodont mutants, animals with such characters were a small but signifiant minority among the population (17% if account is taken on D4's: only 2% after M2's). 6. There was not then any direct and clear correlation between number of lophs (transversal crests) and tooth size, even if the increase of such number goes along with length's increase. 7. Dimensions (length in special) in tetralophodont teeth tend to exceed those in «normal» trilophodont teeth, this being particularly clear in D4, even if there is no clear distinction: the situation is quite the same, maybe less marked, with the M2. 8. According to the preceding conclusions there are no reasons to segregate different taxa among such mastodont population on the grounds of the presence in D4, M1 and M2 of 3 or 4 crests (this character being regarded as diagnostic of the genus Tetralophodon). 9. On the contrary, if any natural (in biological sense) classification is disregarded and a morphological parataxonomy is adopted there should be considered both Gomphotherium angustidens and Tetralophodon sp.: however this is absolutely not our opinion.

Notas sobre depósitos de Taveiro estratigrafia, paleontologia, idade, paleoecologia

This paper reports some research work that has been done to support Geological Survey's field work for the 1:50.000 Carta Geológica de Portugal, (sheets 19-C Figueira da Foz and 19-D Coimbra-Lousã). Its main purpose was to establish the age of some continental formations. At Cerâmica do Mondego, Lda. near Taveiro, two series were observed. The lower one is mainly pelitic, montmorillonite being predominant. It also includes some sandy beds and channel deposits with high energy sediments (conglomerate with limestone pebbles). The upper series lies unconformably upon the former, and there is a neat discontinuity surface between the two. It mainly consists of sands, kaolinite being the most abundant of the clay minerals. This seems to indicate an intensive weathering, an acid, well drained environment and transportation by quite high energy running waters. No fossils were recorded. Preliminary paleontological results are presented, along with some data concerning other localities (Aveiro, etc). Fossils found in the lower series are: gastropoda (Bulimus gaudryi, TV. 15 bed), several vertebrates (TV. 18), fishes (TV. 19?) and plants (TV. 19-TV. 24). Vertebrata belong to the same fauna as that from Vizo, Aveiro, etc. The presence of mammals is most important as only a single tooth was previously know in Europe (Southern France) in Late Cretaceous formations. Elsewhere there are some mammalian remains in Peru besides the rich assemblages found in the USA and Mongolia. Plants are representative of the «Debeya flora» well known at several localities in Beira Litoral province, in «Buçaco sandstones», and in Lisbon's «Basaltic Complex». The most important stratigraphical conclusion is that the lower series is Upper Campanian and/or Maastrichtian in age, and not Tertiary as sometimes it has been considered. As at Aveiro, «Bebeya flora» occurs in-beds somewhat higher than those with the Aveiro-Vizo-Taveiro vertebrate fauna. Correlation with other «Debeya flora» localities are now more clear. Data concerning Taveiro lower series, in the whole, point out to a rather warm (and moist?) environment in an occasionally (seasonally?) flooded region.

Exemplo de vulcanismo tardio em Portugal- rocha ígnea post-Miocénico inferior (Figueira-Algarve)

A small outcrop of an igneous rock (basanite) was observed in 1971 at Figueira-Mexilhoeira Grande-Algarve, enclosed by Miocene limestone and showing clear evidente of low grade thermal effects along the contact with the igneous mass. This is in agreement with F. L. Pereira Sousa who was the first geologist to admit (1917) the existence of Miocene igneous rocks in Algarve although subsequently they were not possible to localize. This work reports studies on petrography and chemical composition of this basanite and describes the evidence of the thermal effects upon the surrounding calcareous rocks. This well localized small outcrop represents an igneous rock more modern than the basaltic complex of Lisbon, hitherto assigned to the Eocene in age and recently ascribed to the Upper Cretaceous and until now considered the most recent manifestation of volcanic activity in Portugal. However this does not exclude the possibility of existence of even more modem igneous rocks in Algarve region.

Application of FTA and the perceived impact on employment policies: the case of nanotechnology in the Netherlands, Germany and Portugal

In this paper we will analyse the usage of FTA to support decision-making in employment policy relate to specific occupational groups. The examples can be better understood if one focus on the nanotechnology and its implications on some sectors (clothing, bio-medical engineering, micro-electronics). When this is done will be clear which occupations will engage a restructuring process (engineers, specialised technicians, qualified machine operators, quality controllers) and what policies are being designed to cope with it. This means toward which extend social partners have driven specific policies on these issues (focused in their sectors).

In-situ X-ray diffraction studies during growth of Ni-Ti shape memory alloy films and their complementary ex-situ characterization

Shape Memory Alloy (SMA) Ni-Ti films have attracted much interest as functional and smart materials due to their unique properties. However, there are still important issues unresolved like formation of film texture and its control as well as substrate effects. Thus, the main challenge is not only the control of the microstructure, including stoichiometry and precipitates, but also the identification and control of the preferential orientation since it is a crucial factor in determining the shape memory behaviour. The aim of this PhD thesis is to study the optimisation of the deposition conditions of films of Ni-Ti in order to obtain the material fully crystallized at the end of the deposition, and to establish a clear relationship between the substrates and texture development. In order to achieve this objective, a two-magnetron sputter deposition chamber has been used allowing to heat and to apply a bias voltage to the substrate. It can be mounted into the six-circle diffractometer of the Rossendorf Beamline (ROBL) at the European Synchrotron Radiation Facility (ESRF), Grenoble, France, enabling an in-situ characterization by X-ray diffraction(XRD) of the films during their growth and annealing. The in-situ studies enable us to identify the different steps of the structural evolution during deposition with a set of parameters as well as to evaluate the effect of changing parameters on the structural characteristics of the deposited film. Besides the in-situ studies, other complementary ex-situ characterization techniques such as XRD at a laboratory source, Rutherford backscattering spectroscopy(RBS), Auger electron spectroscopy (AES), cross-sectional transmission electron microscopy (X-TEM), scanning electron microscopy (SEM), and electrical resistivity (ER) measurements during temperature cycling have been used for a fine structural characterization. In this study, mainly naturally and thermally oxidized Si(100) substrates, TiN buffer layers with different thicknesses (i.e. the TiN topmost layer crystallographic orientation is thickness dependent) and MgO(100) single crystals were used as substrates. The chosen experimental procedure led to a controlled composition and preferential orientation of the films. The type of substrate plays an important role for the texture of the sputtered Ni-Ti films and according to the ER results, the distinct crystallographic orientations of the Ni-Ti films influence their phase transformation characteristics.

The black box of health care expenditure growth determinants

In this paper, the determinants of growth of aggregate health expenditures are investigated. The study departs from previous literature in that it looks at differences across countries in growth (and not levels) of health care expenditures. Estimation is made for 24 OECD countries. Health system characteristics usually believed to influence health expenditures growth, like population ageing, the type of health system (public reimbursement, public contract or integrate) and existence of gatekeepers, are found to be non-significant. Nevertheless, there is evidence that health expenditures experienced a clear slower growth in the last decade. The explanation for this slowdown could not be found in the proposed model and should stimulate further research.

Discovery and retrieval of Geographic data using Google

Dissertation submitted in partial fulfilment of the requirements for the Degree of Master of Science in Geospatial Technologies

Natural populations of saccharomyces kudriavzevii in Portugal are associated with oak bark and are sympatric with s. cerevisiae and s. paradoxus

Applied Environmental Microbiology, Vol. 74, nº7

Cartografia multi-escala de alterações do coberto florestal com imagens de satélite

Dissertação apresentada como requisito parcial para obtenção do grau de Mestre em Ciência e Sistemas de Informação Geográfica