Entity

Time filter

Source Type

Lisbon, Portugal

Universidade Nova de Lisboa ˈnɔvɐ dɨ liʒˈboɐ]) or NOVA is a Portuguese public university established in 1973, in Lisbon and is the youngest of the three public universities of Lisbon. NOVA is a higher education institution with internationally recognized research and quality teaching that ensures high levels of professional success to its students.In 2014, the THE-QS World University Rankings has evaluated NOVA as one of the world's best universities being ranked number 312 in the world. Wikipedia.


Goncalves R.,New University of Lisbon | Camotim D.,University of Lisbon
Thin-Walled Structures | Year: 2012

This paper presents the formulation and validation of a geometrically and physically (J 2 plasticity) non-linear Generalised Beam Theory formulation, intended to calculate accurate non-linear elastoplastic equilibrium paths of thin-walled metal bars and associated collapse loads. This formulation extends previous work (Gonçalves and Camotim, 2011) [1] by including the geometrically non-linear effects. The plate-like bending strains are assumed to be small (as in all GBT formulations), but the membrane strains are calculated exactly. Both stress-based and stress resultant-based GBT approaches are developed and implemented in a 3-node beam finite element. The stress-based formulation is generally more accurate, but the stress resultant-based formulation makes it possible to avoid numeric integration in the through-thickness direction of the walls. In order to show the potential of the proposed formulation and resulting finite element, several numerical results are presented and discussed. For validation purposes, these results are compared with those obtained with standard 2D-solid and shell finite element analyses. © 2011 Elsevier Ltd.


The network of chemical reactions involving anthocyanins and related compounds has been historically considered as the chemical transformations taking place when the flavylium cation (which is generally stable only in very acidic solutions) disappears upon a pH jump to higher pH values (direct pH jump). In this work profit is taken from the appearance of flavylium cation from equilibrated solutions at moderately acid pH values, (reverse pH jumps) as well as upon irradiation of trans-chalcone in the cases where photochemistry is available. Reverse pH jumps, flash photolysis and reaction quantum yields unequivocally show that at sufficiently acidic pH values the tautomerization becomes the rate determining step of flavylium cation formation. This is a lucky situation since gives kinetic information about tautomerization, the most difficult process to access in the anthocyanins and related compounds network of chemical reactions. The thermodynamic and kinetic details of flavylium base photochromic systems are described. Mathematical expressions for direct and reverse pH jumps, stopped flow and flash photolysis are presented as well as the procedure to obtain all of the rate and equilibrium constants of the system. © 2013 Elsevier Ltd. All rights reserved.


Froes F.,Centro Hospitalar Lisbon Norte | Froes F.,New University of Lisbon
Acta Medica Portuguesa | Year: 2013

Introduction and Objectives: Herpes zoster and post-herpetic neuralgia increasing incidence is related to ageing. These conditions can be very debilitating and have an important impact in patients' quality of life. In an ageing population like the Portuguese, is expected that the burden of herpes zoster and post-herpetic neuralgia rises, nevertheless, a specific surveillance system for zoster does not exist in the country, and data regarding the incidence of herpes zoster and the burden of the disease in Portugal in the last decades was not found. In Portugal, the vaccine is still not available. Scaling the burden of disease is important to support public health policies regarding zoster vaccination. Material and Methods: We carried out a retrospective analysis from encoded information from the Portuguese Ministery of Health database for hospital admissions which included all individuals with a primary diagnosis of Herpes Zoster (IDC-9-CM 053), who were discharged between 2000 and 2010. Results: In Portugal, between 2000 and 2010, 1 706 hospital admissions with primary diagnosis of herpes zoster occurred. The majority of the patients were elderly. Eleven percent of the patients had potentially severe immunocompromise. The predominant disease was uncomplicated herpes zoster, followed by nervous system and ophthalmic herpes zoster. Mean hospital stay length was 9.3 days, increasing with age. There was a 1% case fatality rate. Considering the 2000-2009 period and the adult population only, the average annual incidence rate of hospitalization with primary diagnosis of herpes zoster in Portugal was 1.9/100 000 inhabitants, increasing with age. Conclusion: This study confirms that, in Portugal, severe herpes zoster is related to ageing and associated with significant morbidity, mortality and health resources allocation. © Ordem dos Médicos 2013.


This paper proposes that the conduction-free imaginary-part of dielectric constant may be obtained from a convolution between its real-part on a logarithmic scale of frequency and the hyperbolic cosecant function. This equation is, in fact, one of the Kramers-Kronig relations and is deduced from the relationships that relate a distribution of relaxation frequencies both to the real-part and to the conduction-free imaginary-part of the dielectric constant. This simple result has a large practical interest as it allows, for instance, checking for the presence of conductivity on experimental data. © 2013 AIP Publishing LLC.


Vieira Ferreira L.F.,University of Lisbon | Casimiro T.M.,New University of Lisbon | Colomban P.,University Pierre and Marie Curie
Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy | Year: 2013

Two sherds representative of the Portuguese faience production of the first and second halves of the 17th century were studied carefully with the use of non-invasive spectroscopies, namely: Ground State Diffuse Reflectance Absorption (GSDR), micro-Raman, Fourier-Transform Infrared (FT-IR), Laser Induced Luminescence (LIL) and Proton Induced X-ray (PIXE). These results were compared with the ones obtained for a Chinese Ming porcelain, Wanli period (16th/beginning of the 17th centuries), which served as an influence for the initial Lisbon's faience production. By combining information of the different non-destructive spectroscopic techniques used in this work, it was possible to conclude that: Co3O4 (Co II and Co III) can be found in the silicate matrix and is the blue pigment in the "Especieiro" sample (1st half of the 17th C.). Cobalt olivine silicate (Co2SiO 4, Co II only) was clearly identified as the blue pigment in "Aranhões" sample (2nd half of the17th C.)-824 cm-1 band in the micro-Raman-spectrum. Cobalt aluminate (CoAl2O 4, Co II only) is the blue pigment in the Wanli plate-203 and 512 cm-1 bands in the micro-Raman spectrum. The blue pigment in the 1st half 17th century of Lisbon's production was obtained by addition of a cobalt ore in low concentrations, which gives no specific Raman signature, because of complete dissolution in the glass. However, in most cases of the 2nd half 17th century, the Raman signature was quite evident, from a cobalt silicate. These findings point to the use of higher temperature kilns in the second case. © 2012 Elsevier B.V. All rights reserved.


Gaspar T.,New University of Lisbon
International journal of psychology : Journal international de psychologie | Year: 2014

Complex relationships exist between eating behaviour and personal and environmental factors. Rural and urban geographic contexts seem to play a role in eating behaviour, and therefore deserve a deeper study. A healthy eating behaviour and the conditions that promote it are a major issue in the promotion of adolescent health. The study aims to investigate the associations between the area of residence (urban vs. rural), self-regulation strategies (TESQ-E) and eating behaviours among children and adolescents. A total of 11,820 adolescents (50.6% girls) participated in the study, with a mean age of 13.30 years (SD= 2.13). Nine countries (The Netherlands, United Kingdom, Poland, Portugal, Denmark, Romania, Germany, Finland and Belgium) completed a questionnaire in the school context, asking about the use of self-regulation strategies, eating behaviour awareness/care and sociodemographic questions such as age, gender and residential area. Both areas of residence (urban vs. rural) are associated with eating awareness/care in Romania and Portugal, controlling for age, gender and self-regulation strategies. In some European countries at least, and most probably around the world, health promotion should focus on an ecological approach that includes the understanding of the effect of both environmental factors and personal skills on eating behaviour/awareness. © 2014 International Union of Psychological Science.


Chakraborty S.,University of Michigan | Chakraborty S.,University of Illinois at Urbana - Champaign | Iranzo O.,University of Michigan | Iranzo O.,New University of Lisbon | And 2 more authors.
Journal of the American Chemical Society | Year: 2012

An important factor that defines the toxicity of elements such as cadmium(II), mercury(II), and lead(II) with biological macromolecules is metal ion exchange dynamics. Intriguingly, little is known about the fundamental rates and mechanisms of metal ion exchange into proteins, especially helical bundles. Herein, we investigate the exchange kinetics of Cd(II) using de novo designed three-stranded coiled-coil peptides that contain metal complexing cysteine thiolates as a model for the incorporation of this ion into trimeric, parallel coiled coils. Peptides were designed containing both a single Cd(II) binding site, GrandL12AL16C [Grand = AcG-(LKALEEK) 5-GNH 2], GrandL26AL30C, and GrandL26AE28QL30C, as well as GrandL12AL16CL26AL30C with two Cd(II) binding sites. The binding of Cd(II) to any of these sites is of high affinity (K A > 3 × 10 7 M -1). Using 113Cd NMR spectroscopy, Cd(II) binding to these designed peptides was monitored. While the Cd(II) binding is in extreme slow exchange regime without showing any chemical shift changes, incremental line broadening for the bound 113Cd(II) signal is observed when excess 113Cd(II) is titrated into the peptides. Most dramatically, for one site, L26AL30C, all 113Cd(II) NMR signals disappear once a 1.7:1 ratio of Cd(II)/(peptide) 3 is reached. The observed processes are not compatible with a simple "free-bound" two-site exchange kinetics at any time regime. The experimental results can, however, be simulated in detail with a multisite binding model, which features additional Cd(II) binding site(s) which, once occupied, perturb the primary binding site. This model is expanded into differential equations for five-site NMR chemical exchange. The numerical integration of these equations exhibits progressive loss of the primary site NMR signal without a chemical shift change and with limited line broadening, in good agreement with the observed experimental data. The mathematical model is interpreted in molecular terms as representing binding of excess Cd(II) to surface Glu residues located at the helical interfaces. In the absence of Cd(II), the Glu residues stabilize the three-helical structure though salt bridge interactions with surface Lys residues. We hypothesize that Cd(II) interferes with these surface ion pairs, destabilizing the helical structure, and perturbing the primary Cd(II) binding site. This hypothesis is supported by the observation that the Cd(II)-excess line broadening is attenuated in GrandL26AE28QL30C, where a surface Glu(28), close to the metal binding site, was changed to Gln. The external binding site may function as an entry pathway for Cd(II) to find its internal binding site following a molecular rearrangement which may serve as a basis for our understanding of metal complexation, transport, and exchange in complex native systems containing α-helical bundles. © 2012 American Chemical Society.


Tschopp E.,University of Turin | Tschopp E.,New University of Lisbon
PLoS ONE | Year: 2016

Vertebral laminae are bony ridges or sheets that connect important morphological landmarks on the vertebrae, like diapophyses or zygapophyses. They usually exhibit some serial variation throughout the column. A consistent terminology facilitates the morphological description of this variation, and the recognition of patterns that could be taxonomically significant and could serve as phylogenetic characters. Such a terminology was designed for saurischian dinosaurs, and has also been applied to other members of Archosauriformes. Herein, this terminology is applied for the first time to lizards (Squamata). Probably due to their generally smaller size compared to saurischian dinosaurs, lizards have less developed vertebral laminae. Some laminae could not be recognized in this group and others require new names to account for differences in basic vertebral morphology. For instance, the fusion of diapophysis and parapophysis in lacertids into a structure called synapophysis necessitates the creation of the new term synapophyseal laminae for both diapophyseal and parapophyseal laminae. An assessment of occurrence and serial variation in a number of lacertid species shows that some laminae develop throughout ontogeny or only occur in large-sized species, whereas the distribution of other laminae might prove to be taxonomically significant in future. © 2016 Emanuel Tschopp.This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.


Pina F.,New University of Lisbon
Journal of Agricultural and Food Chemistry | Year: 2014

Independently of the natural or synthetic origin, flavylium derivatives follow the same network of chemical reactions. Actually, the flavylium cation is stable only at low pH values. Increasing the pH gives rise to the formation of several species: quinoidal bases, hemiketal, cis- and trans-chalcones, and their deprotonated forms. A deep knowledge of the thermodynamics and kinetics of these species is an essential tool to practical applications of these compounds, in particular, in the domain of food chemistry. In this work the network of chemical reactions involving flavylium derivatives is presented, and the respective thermodynamics and kinetics are discussed in detail, including the mathematical expressions and a step-by-step procedure to calculate all of the rate and equilibrium constants of the system. Examples of systems possessing a high or low cis-trans isomerization barrier are shown. Recent practical applications of anthocyanins and related compounds illustrate the potentialities of the flavylium-based family of compounds. © 2014 American Chemical Society.


Nunes J.P.,University of Aveiro | Seixas J.,New University of Lisbon | Keizer J.J.,University of Aveiro
Catena | Year: 2013

Climate change in the Mediterranean is expected to lead to lower total rainfall and soil moisture, together with higher storm intensities; different vegetation types are expected to react positively or negatively to these and other changes. Climate change could therefore have positive or negative impacts on runoff and soil erosion during storms, and previous research has indicated that the impacts could be different at the field, hillslope and catchment scales. This problem was assessed for two Mediterranean watersheds by a combined application of the PROMES regional climate model, the SWAT continuous hydrological and vegetation model, and the MEFIDIS storm runoff and erosion model. PROMES results were used to estimate changes to storm rainfall intensity, while SWAT was applied with the PROMES results to estimate changes to soil moisture and saturation deficit, as well as vegetation cover. The results from both models were used to generate scenarios of changes to storm intensity (increasing), saturation deficit (increasing) and vegetation cover (increasing according to vegetation type). These scenarios were used as input for the MEFIDIS model to study the impacts of these changes on runoff and soil erosion across spatial scales for a set of storms. The simulation results indicate that (i) the increase in saturation deficit and vegetation cover is sufficient, in many cases, to decrease or counterbalance the impacts of increased storm intensity on soil erosion at all spatial scales; (ii) catchment sediment yield is noticeably more sensitive to the climate change scenarios than within-watershed soil erosion, mostly due to the impacts of changes to saturation deficit and vegetation cover on connectivity; (iii) within the watershed, impacts on soil erosion vary with landcover type, with croplands suffering the most negative impacts. © 2011 Elsevier B.V.


Dimitrovova Z.,New University of Lisbon | Rodrigues H.C.,University of Lisbon
Structural and Multidisciplinary Optimization | Year: 2010

The contribution of optimization has been essential to the more recent developments in design of new mechanical structures and materials. The objective of this work is to apply the models of material and structural optimization to the design of passive vibration isolators. A computational tool to identify the optimal viscoelastic characteristics of a nonlinear one-dimensional isolator was developed. The cost functional involves the minimization of a weighted average of the maximum transient and steady state response amplitudes for a set of predefined dynamic loads. The optimal isolator behaviour is obtained by a simulated annealing method. The solutions obtained are analyzed and discussed concerning their dependence on the applied forces and objective function selection. The results obtained can facilitate the design of elastomeric materials with improved behaviour in terms of dynamic stiffness for passive vibration control.


Scheven U.M.,New University of Lisbon
Journal of Magnetic Resonance | Year: 2013

This paper describes a new variant of established stimulated echo pulse sequences, and an analytical method for determining diffusion or dispersion coefficients for Gaussian or non-Gaussian displacement distributions. The unipolar displacement encoding PFGSTE sequence uses trapezoidal gradient pulses of equal amplitude g and equal ramp rates throughout while sampling positive and negative halves of q-space. Usefully, the equal gradient amplitudes and gradient ramp rates help to reduce the impact of experimental artefacts caused by residual amplifier transients, eddy currents, or ferromagnetic hysteresis in components of the NMR magnet. The pulse sequence was validated with measurements of diffusion in water and of dispersion in flow through a packing of spheres. The analytical method introduced here permits the robust determination of the variance of non-Gaussian, dispersive displacement distributions. The noise sensitivity of the analytical method is shown to be negligible, using a demonstration experiment with a non-Gaussian longitudinal displacement distribution, measured on flow through a packing of mono-sized spheres. © 2013 Elsevier Inc. All rights reserved.


Fontoura P.,Roche Holding AG | Fontoura P.,New University of Lisbon
mAbs | Year: 2010

Therapeutic approaches to multiple sclerosis (MS) are based on altering the functions of the immune system, either by using broad immunosuppressive drugs used for transplantation rejection and rheumatology, or by modulating them more discreetly with beta interferon and synthetic amino-acid copolymers. These strategies are only partially successful, have important safety and tolerability limitations, and have shown to be mostly effective in earlier stages of the disease, in which acute relapses dominate the clinical picture. For progressive phenotypes of MS there are currently no effective therapeutic options. As very specific and potent immunosuppressive agents, monoclonal antibodies (mAbs) may offer considerable advantages over other therapies for MS. During the last decade, anti-a4 integrin natalizumab became the first approved mAb for treatment of relapsing MS, after convincingly demonstrating clinically significant effects on two large Phase 3 trials. Moreover, the concept of disease remission was introduced for the first time to describe patients who show no signs of clinical or imaging markers of disease activity during therapy with natalizumab. Of the mAbs under development for MS, alemtuzumab and rituximab have also shown promising evidence of effectiveness and potentially expanded the therapeutic horizon to reversal of disease progression in early relapsing patients and progressive patients who previously had not been studied. However, the appearance of progressive multifocal leukoencephalopathy (PML) in natalizumab-treated MS patients, as well as in patients with lymphoma, lupus and rheumatoid arthritis, treated with rituximab and autoimmune-type complications in alemtuzumab-treated MS patients underlines the fact that extended efficacy comes with significant clinical risks. The challenge is then how best to utilize therapies that have evidently superior efficacy in a chronic disease of young adults to obtain the best benefit-risk ratio and how to monitor and prevent emergent safety concerns. © 2010 Landes Bioscience.


Malcata F.X.,Superior Institute of Maia | Malcata F.X.,CIIMAR - Interdisciplinary Center of Marine and Environmental | Malcata F.X.,New University of Lisbon
Trends in Biotechnology | Year: 2011

Microalgae have much higher lipid yields than those of agricultural oleaginosous crops, and they do not compromise arable land. Despite this, current microalga-based processes suffer from several constraints pertaining to the biocatalyst and the bioreactor, which hamper technologically and economically feasible scale-up. Here, we briefly review recent active research and development efforts worldwide, and discuss the most relevant shortcomings of microalgal biofuels. This review goes one step further relative to related studies, because it tackles otherwise scarcely mentioned issues - for example, heterotrophic versus autotrophic metabolism, alkane versus glyceride synthesis, conduction versus bubbling of CO 2, and excretion versus accumulation of lipids. Besides promising solutions that have been hypothesized and arise from multidisciplinary approaches, we also consider less conventional ones. Microalgae and biofuels hold indeed a promising partnership, but a fully competitive technology is not expected to be available before the end of this decade, because the need for one order of magnitude increase in productivity requires development of novel apparatuses and transformed cells. © 2011.


Araya Y.H.,York University | Cabral P.,New University of Lisbon
Remote Sensing | Year: 2010

The expansion of cities entails the abandonment of forest and agricultural lands, and these lands' conversion into urban areas, which results in substantial impacts on ecosystems. Monitoring these changes and planning urban development can be successfully achieved using multitemporal remotely sensed data, spatial metrics, and modeling. In this paper, urban land use change analysis and modeling was carried out for the Concelhos of Setúbal and Sesimbra in Portugal. An existing land cover map for the year 1990, together with two derived land cover maps from multispectral satellite images for the years 2000 and 2006, were utilized using an object-oriented classification approach. Classification accuracy assessment revealed satisfactory results that fulfilled minimum standard accuracy levels. Urban land use dynamics, in terms of both patterns and quantities, were studied using selected landscape metrics and the Shannon Entropy index. Results show that urban areas increased by 91.11% between 1990 and 2006. In contrast, the change was only 6.34% between 2000 and 2006. The entropy value was 0.73 for both municipalities in 1990, indicating a high rate of urban sprawl in the area. In 2006, this value, for both Sesimbra and Setúbal, reached almost 0.90. This is demonstrative of a tendency toward intensive urban sprawl. Urban land use change for the year 2020 was modeled using a Cellular Automata based approach. The predictive power of the model was successfully validated using Kappa variations. Projected land cover changes show a growing tendency in urban land use, which might threaten areas that are currently reserved for natural parks and agricultural lands. © 2010 by the authors; licensee MDPI, Basel, Switzerland.


Swift T.,New University of Lisbon
Theory and Practice of Logic Programming | Year: 2012

The paradigm of Tabled Logic Programming (TLP) is now supported by a number of Prolog systems, including XSB, YAP Prolog, B-Prolog, Mercury, ALS, and Ciao. The reasons for this are partly theoretical: tabling ensures termination and optimal known complexity for queries to a large class of programs. However, the overriding reasons are practical. TLP allows sophisticated programs to be written concisely and efficiently, especially when mechanisms such as tabled negation and call and answer subsumption are supported. As a result, TLP has now been used in a variety of applications from program analysis to querying over the semantic web. This paper provides a survey of TLP and its applications as implemented in the XSB Prolog, along with discussion of how XSB supports tabling with dynamically changing code, and in a multi-threaded environment. © Copyright Cambridge University Press 2012.


Mascarenhas A.,University of Algarve | Ramos T.B.,New University of Lisbon | Nunes L.,University of Algarve
Land Use Policy | Year: 2012

Monitoring is a challenging and fundamental issue within planning processes, yet there is little understanding as to whether plans achieved their goals in guaranteeing sustainable development on a territorial level. Follow-up of spatial planning is rather difficult due to insufficient methodologies, deficiencies in plans' contents and resource limitations. The main goal of this research is to develop and test a conceptual framework to support the development of effective indicator based regional spatial plans' (RSPs) monitoring systems. The conceptual framework includes indicators with distinct purposes and has the following features: (i) it establishes links between RSPs, their strategic environmental assessment and monitoring indicators; (ii) it incorporates the contribution of other existing monitoring systems in the regions; and (iii) it defines specific indicator selection criteria. In order to inform the development of the conceptual framework we: (i) review international practice of RSP monitoring; (ii) analyse the features of current Portuguese RSPs; (iii) test the conceptual framework using the RSP and the regional sustainability indicator system of the Algarve region (Portugal) as a case study. Two types of indicators were developed - output/implementation and results/effects - for improving the identification of cause-effect relationships between RSP implementation and associated territorial effects; although this is a continuing challenge, given the strategic nature of RSPs. The usefulness of the conceptual framework was demonstrated in the definition of monitoring indicators for the Algarve's RSP, as well as in the integration of an existing regional sustainability monitoring system. © 2011 Elsevier Ltd.


Mosquitoes are dipterous insects, responsible for the transmission of several pathogenic agents to humans, causing vector-borne diseases, such as malaria, lymphatic and other filariasis, and several arboviral diseases such as yellow fever and dengue. In this revision, Culicidae or mosquitoes are summarily characterized, as well as their bioecology, internal morphology, digestive and egg maturation physiology, and the main methods for their collection and control. The epidemiology of mosquito-borne diseases depends on parameters such as Vectorial efficiency, Vector competence and Vectorial capacity, the concepts of which are presented. Forty one species of mosquitoes have been detected so far in mainland Portugal. Malaria was endemic till 1959, yellow fever outbreaks were registered in the XIX century, and human cases of dirofilarisis and West Nile fever have been detected. In face of the current climate changes in course and the threat of the (re)-introduction of exotic mosquito species, not only new cases of some of these diseases may occur, increasing their risk, but also other mosquito-borne diseases may be introduced constituting challenges for the XXI century, demanding a continued surveillance in a Public Health perspective. © 2011 CELOM.


Trubenbach K.,University of Lisbon | Teixeira T.,University of Lisbon | Diniz M.,New University of Lisbon | Rosa R.,University of Lisbon
Deep-Sea Research Part II: Topical Studies in Oceanography | Year: 2013

Jumbo squid (Dosidicus gigas) is a large oceanic squid endemic off the Eastern Tropical Pacific that undertakes diel vertical migrations into mesopelagic oxygen minimum zones. One of the expected physiological effects of such migration is the generation of reactive oxygen species (ROS) at the surface, promoted by the transition between hypoxia and reoxygenation states. The aim of this study was to investigate the energy expenditure rates and the antioxidant stress strategies of juvenile D. gigas under normoxia and hypoxia, namely by quantifying oxygen consumption rates, antioxidant enzyme activities [including superoxide dismutase (SOD), catalase (CAT) and glutathione-S-transferase (GST)], heat shock protein expression (Hsp70/Hsc70), and lipid peroxidation [malondialdehyde (MDA) levels]. A high significant decrease (68%) in squid's metabolic rates was observed during hypoxia (p<0.05). This process of metabolic suppression was followed by a significant increase in Hsp70/Hsc70 expression (p<0.05), which may be interpreted as a strategy to prevent post-hypoxic oxidative damage during the squid's night upwards migration to the surface ocean. On the other hand, in normoxia, the higher SOD and CAT activities seemed to be a strategy to cope with the reoxygenation process, and may constitute an integrated stress response at shallower depths. GST activity and MDA concentrations did not change significantly from normoxia to hypoxia (p>0.05), with the latter indicating no enhancement of lipid peroxidation (i.e. cellular damage) at the warmer and normoxic surface waters. The understanding of such physiological strategies that are linked to oxygen deprivation and reoxygenation phases may provide valuable information about how this species is quickly responding to the impacts of environmental stressors coupled with global climate change. © 2012 Elsevier Ltd.


Barrocas B.,University of Lisbon | Monteiro O.C.,University of Lisbon | Jorge M.E.M.,University of Lisbon | Serio S.,New University of Lisbon
Applied Surface Science | Year: 2013

The photocatalytic activity of nanocrystalline titanium dioxide (TiO 2) films deposited on unheated glass substrates by DC reactive magnetron sputtering at different oxygen partial pressures was tested on the decolorization of Rhodamine 6G (Rh6G) aqueous solutions. The dye photodecolorization process was studied considering the influence of the crystallinity and preferred orientation of growth of the prepared films. It was found that the higher photocatalytic activity was achieved by the film with preferred orientation of growth along the (1 0 1) crystal direction and showing a vestigial rutile phase in a mainly anatase phase. The recycling catalytic ability of the TiO2 films was also evaluated and a promising photocatalytic performance has been revealed with a very low variation of the decay rate after five consecutive usages. Structural and morphological characterization revealed high photochemical stability of the films after successive photodegradations assays. © 2012 Elsevier B.V. All rights reserved.


Calado J.,New University of Lisbon
Kidney international. Supplement | Year: 2011

Reabsorption of glucose in the proximal renal tubule involves the Na(+)-coupled glucose cotransporter (SGLT) and the facilitative glucose transport (GLUT) multigene glucose transport families. Mutations in SLC5A2, the SGLT2 coding gene, are responsible for familial renal glucosuria (FRG), a genetic disorder characterized by glucosuria in the absence of both hyperglycemia and generalized proximal tubular dysfunction. In this paper we focus on FRG and describe other inherited and acquired clinical conditions associated with glucosuria. In addition, a brief review on the regulation of renal glucose transport in diabetes is provided.


Pereira M.F.,University of Evora | Apraiz A.,University of the Basque Country | Chichorro M.,New University of Lisbon | Silva J.B.,University of Lisbon | Armstrong R.A.,Australian National University
Gondwana Research | Year: 2010

The Coimbra-Córdoba shear zone (CCSZ) represents a major intra-continental shear zone of the European Variscan orogen. The shear criteria found in metamorphic rocks of the CCSZ are consistent with sinistral transcurrent movements. Isoclinal and open folds with axes parallel to the stretching lineation are responsible for dip variations in the mylonitic foliation, but are related to the same kinematics. In selected outcrops of the Campo Maior unit (SW Iberian Massif, Portugal), boudins of high-pressure mafic granulites, high-grade amphibolites and felsic gneisses with long-axes parallel to the stretching lineation in the surrounded metamorphic rocks, were sampled together with the host migmatites for petrographic, geothermobarometric and U-Th-Pb SHRIMP in-situ zircon geochronology analysis. The results show that decompression associated with shearing and partial melting in the CCSZ began under granulite facies conditions during the Variscan orogeny (early Carboniferous: c. 340 Ma.). Peak metamorphic conditions in the mafic granulites (850-880 °C and 14.5-16.5 kbar), were followed by symplectitization at 725-750 °C and 12.5-14.5 kbar. Peak P-T conditions were 615-675 °C and 9.5-11.5 kbar in the high-grade amphibolites, 750-850 °C and 11.5-15.5 kbar in the weakly deformed gneisses, and 675-725 °C and 9-11.5 kbar in the sheared migmatites. Subsequently, temperatures and pressures decreased during amphibolite facies metamorphism coeval with mylonitization. Retrograde P-T conditions were 550-700 °C and 7-9 kbar in the high-grade amphibolite, 620-640 °C and 6-8 kbar in the gneisses, and 560-610 °C and 5-6.5 kbar in the migmatites. Zircon dating of the migmatites and gneisses indicate Ediacaran (c. 590 Ma) and Ordovician (c. 488-479 Ma) ages for the protoliths, and show that these rocks were part of the northern Gondwana margin with a West Africa Craton signature dominated by Paleoproterozoic (c. 2-1.8 Ga) and Neoproterozoic (c. 664-555 Ma) ages, and a characteristic lack of Mesoproterozoic (c. 0.9-1.7 Ga) ages. These rocks were probably subducted, and subsequently exhumed during the complex processes of Pangea formation. The high temperature-high pressure rocks of the Campo Maior unit were likely displaced by large-scale transcurrent movements within the CCSZ in the early Carboniferous. The CCSZ appears to represent a major shear zone in the SW Iberian Massif connected in some way to the Variscan suture zone. © 2009 International Association for Gondwana Research.


Scheven U.M.,New University of Lisbon
AIChE Journal | Year: 2010

This work reanalyzes published time series dispersion traces (Han et al., AIChE J. 1985;31:277-288) from step input tracer passages recorded at different locations along the length of a packed bed filled with monodisperse solid spheres. The intrinsic dispersivity and sample dependent dispersion are separated by imposing a heuristic model where coarse grained axial advection velocities vary in a plane perpendicular to the flow but not along the direction of flow. The derived intrinsic dispersivity agrees with the predicted value (Scheven et al., Phys Rev Lett. 2007;99:054502-1-054502-4). It serves as a bench mark for different implementations of simulations coupling Stokes flow and diffusion in random geometries, and for experimental tests of injection and packing methods. Conceptually, a well defined and fittable effective dispersivity is introduced in an analytical framework describing dispersion data obtained in non-ideal packed beds, where elution profiles cannot be fitted to the solution of the one dimensional advection diffusion equation. © 2009 American Institute of Chemical Engineers.


Riguzzi F.,University of Ferrara | Swift T.,New University of Lisbon
Theory and Practice of Logic Programming | Year: 2013

Distribution semantics is one of the most prominent approaches for the combination of logic programming and probability theory. Many languages follow this semantics, such as Independent Choice Logic, PRISM, pD, Logic Programs with Annotated Disjunctions (LPADs), and ProbLog. When a program contains functions symbols, the distribution semantics is well-defined only if the set of explanations for a query is finite and so is each explanation. Well-definedness is usually either explicitly imposed or is achieved by severely limiting the class of allowed programs. In this paper, we identify a larger class of programs for which the semantics is well-defined together with an efficient procedure for computing the probability of queries. Since Logic Programs with Annotated Disjunctions offer the most general syntax, we present our results for them, but our results are applicable to all languages under the distribution semantics. We present the algorithm Probabilistic Inference with Tabling and Answer subsumption (PITA) that computes the probability of queries by transforming a probabilistic program into a normal program and then applying SLG resolution with answer subsumption. PITA has been implemented in XSB and tested on six domains: two with function symbols and four without. The execution times are compared with those of ProbLog, cplint, and CVE. PITA was almost always able to solve larger problems in a shorter time, on domains with and without function symbols. © 2012 Cambridge University Press.


Cabrita L.,New University of Lisbon
Natural Product Communications | Year: 2015

An acylated anthocyanin trioside was isolated from pink flowers of Convolvulus althaeoides using a combination of chromatographic techniques. On the basis of MS (MALDI-TOF) and NMR (1H NMR, 1H-1H COSY, 1D TOCSY, HSQC, HMBC, 13C CAPT) its structure was determined as cyanidin 3-O-[6-O-(4-O-(6-O-(E-caffeoyl)-β-D-glucopyranosyl)-α-L-rhamnopyranosyl)-β-D-glucopyranoside]-5-O-β-D-glucopyranoside. The absolute configuration of the aldose enantiomer moieties was determined from the separation of the corresponding thiazolidine diastereoisomer derivatives by HPLC-DAD. This is a novel trisaccharide within the flavonoids, and the first complete characterization of a linear glucosyl-rhamnosyl-glucoside (4'-glucosylrutinoside) within the anthocyanins. Whilst acylation of rhamnose moieties in position 4 is quite common, the occurrence in anthocyanins of a glycosylated rhamnose is a unique trait. Although many complex anthocyanins have been found amongst the Convolvulaceae, the genus Convolvulus had not yet been surveyed for anthocyanins and thus this account could be of significance within the current chemotaxonomy of this family.


Clement T.,Ecole Polytechnique Federale de Lausanne | Pinho Ramos A.,New University of Lisbon | Fernandez Ruiz M.,Ecole Polytechnique Federale de Lausanne | Muttoni A.,Ecole Polytechnique Federale de Lausanne
Engineering Structures | Year: 2014

Previous researches on punching of post-tensioned slabs have shown a number of phenomena significantly influencing their strength and behaviour. However, no general agreement is yet found on a physical theory (either in codes of practice or in design models) suitably describing the influence of prestressing and how should it be accounted on the punching shear behaviour. In this paper, the authors present the results of tests on 15 slabs (3000. ×. 3000. ×. 250. mm) tested to failure under different loading conditions. The aim of the tests was to investigate in a separate manner the different actions induced by prestressing on the punching shear strength (in-plane forces, bending moments and bonded tendons). These results are finally investigated on the basis of the physical model of the Critical Shear Crack Theory. The fundamentals of this theory are presented and adapted to post-tensioned slabs, providing a rational explanation of the observed phenomena and measured strengths. © 2014 Elsevier Ltd.


Sardinha I.D.,University of Lisbon | Reijnders L.,University of Amsterdam | Antunes P.,New University of Lisbon
Journal of Cleaner Production | Year: 2011

Shopping centres that include retail activities have come in for criticism as to their environmental, architectural and social impacts. However, the sector has been applying corporate social responsibility (CSR) practices. In an attempt to identify the best practices regarding CSR and trends therein we developed a CSR benchmarking of companies from the real estate sector owning and developing shopping centres. Based on information from websites, annual, environmental and sustainability reports, and customer services department's information, in 2004 and 2010, a comparative CSR benchmarking was performed on 23 real estate companies with shopping centres based in Europe, China, Australia and the USA. The CRS benchmarking framework focused on reported CSR practices and included categories and sub-categories of evaluation in four domains: (1) external results, (2) internal results, (3) management processes and (4) learning and innovation. The framework was inspired by the sustainability balanced scorecard structure. The United Kingdom real estate sector's companies studied did relatively well when evaluated by the framework used in this study. The highest ranked real estate companies applied sustainable or environmental buildings standards and did show a commitment to transparency and CSR disclosure. The positive evolution of CSR practices in the 23 companies studied in 2004 and 2010 may reflect efforts to improve competitiveness and the reputation of the companies with shopping centres through CSR initiatives. © 2011 Elsevier Ltd. All rights reserved.


Palma A.S.,Imperial College London | Palma A.S.,New University of Lisbon | Feizi T.,Imperial College London | Childs R.A.,Imperial College London | And 2 more authors.
Current Opinion in Chemical Biology | Year: 2014

The neoglycolipid (NGL) technology is the basis of a state-of-the-art oligosaccharide microarray system. The NGL-based microarray system in the Glycosciences Laboratory Imperial College London (http://www3.imperial.ac.uk/glycosciences) is one of the two leading platforms for glycan microarrays, being offered for screening analyses to the broad biomedical community. Highlighted in this review are the sensitivity of the analysis system and, coupled with mass spectrometry, the provision for generating 'designer' microarrays from glycomes to identify novel ligands of biological relevance. Among recent applications are assignments of ligands for apicomplexan parasites, pandemic 2009 influenza virus, polyoma and reoviruses, an innate immune receptor against fungal pathogens, Dectin-1, and a novel protein of the endoplasmic reticulum, malectin; also the characterization of an elusive cancer-associated antigen. Some other contemporary advances in glycolipid-containing arrays and microarrays are also discussed. © 2014 The Authors.


Fliedel C.,New University of Lisbon | Braunstein P.,CNRS Coordination Chemistry
Journal of Organometallic Chemistry | Year: 2014

This review summarizes the recent progress in the field of S-functionalized N-heterocyclic carbene ligands and their metal complexes. The syntheses of the azolium precursors and of the corresponding metal complexes are discussed as a function of the five different S-containing chemical groups examined here: thiolate, thioether, thiophene, sulfonate and thione. In addition to an example of application of dithienyl-functionalized NHC acting as a switchable organocatalyst, the properties of the S-functionalized NHC metal complexes are discussed for each category of ligand, and are mostly related to applications in homogeneous catalysis. © 2013 Elsevier B.V. All rights reserved.


Ludovico-Marques M.,Polytechnic Institute of Setubal | Chastre C.,New University of Lisbon
Engineering Failure Analysis | Year: 2012

Sandstone building stones are important in the building elements of Portuguese monuments, particularly in the western and southern regions. Alveolization due to salt crystallization was the most important degradation pattern found in the old sandstone façades of buildings in the village of Atouguia da Baleia. Because weathering progressively increases porosity in stones, experimental research was conducted on the most porous variety of sandstone, which is similar to the type of stones found in the façades of ancient buildings in that village. An automatic salt crystallization accelerated ageing chamber was developed. Monotonic and cyclic uniaxial compressive tests were carried out on samples after sodium chloride crystallization ageing tests had been performed, in order to assess the compressive mechanical behavior of sandstone during accelerated ageing. The results of stress-strain compression diagrams showed a clear decreasing trend in the values of mechanical parameters during the salt crystallization ageing progress. The difference in compressive strength values between monotonic and cyclic compression also decreases with as salt crystallization ageing progresses. A predictive equation that correlates the compressive strength of sandstones with salt crystallization ageing cycles is proposed. © 2012 Elsevier Ltd.


Enguita F.J.,University of Lisbon | Leitao A.L.,New University of Lisbon
BioMed Research International | Year: 2013

Hydroquinone is a major benzene metabolite, which is a well-known haematotoxic and carcinogenic agent associated with malignancy in occupational environments. Human exposure to hydroquinone can occur by dietary, occupational, and environmental sources. In the environment, hydroquinone showed increased toxicity for aquatic organisms, being less harmful for bacteria and fungi. Recent pieces of evidence showed that hydroquinone is able to enhance carcinogenic risk by generating DNA damage and also to compromise the general immune responses which may contribute to the impaired triggering of the host immune reaction. Hydroquinone bioremediation from natural and contaminated sources can be achieved by the use of a diverse group of microorganisms, ranging from bacteria to fungi, which harbor very complex enzymatic systems able to metabolize hydroquinone either under aerobic or anaerobic conditions. Due to the recent research development on hydroquinone, this review underscores not only the mechanisms of hydroquinone biotransformation and the role of microorganisms and their enzymes in this process, but also its toxicity. © 2013 Francisco J. Enguita and Ana Lúcia Leitão.


Christiansen N.A.,Museu da Lourinha | Tschopp E.,New University of Lisbon
Swiss Journal of Geosciences | Year: 2010

Dinosaur skin impressions are rare in the Upper Jurassic Morrison Formation, but different sites on the Howe Ranch in Wyoming (USA), comprising specimens from diplodocid, camarasaurid, allosaurid and stegosaurian dinosaurs, have proven to be a treasure-trove for these soft-tissue remains. Here we describe stegosaurian skin impressions from North America for the first time, as well as the first case of preservation of an impression of the integument that covered the dorsal plates of stegosaurian dinosaurs in life. Both have been found closely associated with bones of a specimen of the stegosaurian Hesperosaurus mjosi Carpenter, Miles and Cloward 2001. The scales of the skin impression of H. mjosi are very similar in shape and arrangement to those of Gigantspinosaurus sichuanensis Ouyang 1992, the only other stegosaurian dinosaur from which skin impressions have been described. Both taxa show a ground pattern of small polygonal scales, which in some places is interrupted by larger oval tubercles surrounded by the small scales, resulting in rosette-like structures. The respective phylogenetic positions of G. sichuanensis as a basal stegosaurian and H. mjosi as a derived form suggest that most stegosaurians had very similar skin structures, which also match the most common textures known in dinosaurs. The integumentary impression from the dorsal plate brings new data to the long-lasting debate concerning the function of dorsal plates in stegosaurian dinosaurs. Unlike usual dinosaur skin impressions, the integument covering the dorsal plates does not show any scale-like texture. It is smooth with long and parallel, shallow grooves, a structure that is interpreted as representing a keratinous covering of the plates. The presence of such a keratinous covering has affects on all the existing theories concerning the function of stegosaurian plates, including defense, thermoregulation, and display, but does not permit to rule out any of them. © 2010 Swiss Geological Society.


Nunes I.L.,New University of Lisbon
Journal of Applied Engineering Science | Year: 2012

This paper presents the potentialities of Fuzzy Set Theory to deal with complex, incomplete and/or vague information which is characteristic of some industrial engineering problems. Two systems that were developed to support the activities of industrial engineering managers are presented as examples of the use of this mathematical methodology. Work related musculoskeletal disorders, Ergonomics, Resilience, Supply chain, disturbances, Industrial engineering, Fuzzy systems.


Ramos T.B.,New University of Lisbon | Caeiro S.,University of Lisbon
Ecological Indicators | Year: 2010

There are many different kinds of frameworks for evaluating environmental and sustainability performance at the organizational level (profit or not-for-profit, private or public), sectoral level (e.g. industry, transport, agriculture and tourism), and local, regional or country levels. Despite the diversity of methods and tools to measure sustainable development, indicators are one of the approaches most used. However, these tools do not usually include evaluation of the performance measurement instrument itself. The main objective of this research is to develop a conceptual framework to design and assess the effectiveness of the sustainability indicators themselves. To put the proposed tool into practice, a set of key good-practice factors and meta-performance evaluation indicators is proposed for adoption in a national case study-the national sustainable development indicators system, SIDS Portugal, and the usefulness of this methodology is demonstrated. This approach aims to evaluate how appropriate a set of sustainability indicators is and allow an evaluation of overall performance-monitoring activities and results. Stakeholder involvement is an essential component of the proposed framework. The tool developed could support continuous improvement in the performance of ongoing sustainability indicator initiatives, allowing greater guidance, objectivity and transparency in sustainability assessment processes. © 2009 Elsevier Ltd. All rights reserved.


Rodrigues R.,New University of Lisbon
Physiological Measurement | Year: 2014

We present a method for location of fetal QRS in maternal abdominal ECG recordings. This method's initial, global approach was proposed in the context of the 2013 PhysioNet/Computing in Cardiology Challenge where it was tested on the 447 four channel one-minute recordings. The first step is filtering to eliminate baseline wander and high frequency noise. Upon detection, maternal QRS is removed on each channel using a filter applied to the other three channels. Next we locate fetal QRS on each channel and select the channel with the best set of detections. The method was awarded the third-best score in the Challenge event 1 with 278.755 (beats/minute) and the fourth-best score on event 2 with 28.201ms. The 5min long recordings of the Abdominal and Direct Fetal ECG Database were used to further test the method. This database contains five recordings obtained from women in labor. Results in these longer recordings were not satisfactory. This appears to be particularly the case in recordings with a more clearly non-stationary nature. In a new approach to our method, some changes are introduced. Two features are updated over time: the filter used to eliminate maternal QRS and the channel used to detect fetal beats. These changes significantly improved the QRS detection performance on longer recordings, but the scores on the 1minute Challenge recordings were degraded. © 2014 Institute of Physics and Engineering in Medicine.


Ferreira Da Silva A.R.,New University of Lisbon
IJCCI 2012 - Proceedings of the 4th International Joint Conference on Computational Intelligence | Year: 2012

Diffusion anisotropy has been used to characterize white matter neuronal pathways in the human brain, and infer global connectivity in the central nervous system. However, mapping complex fiber configurations in vivo remains a challenging task. We present a new methodology to reduce uncertainty in estimating the orientation of neuronal pathways in high angular resolution diffusion imaging (HARDI) reconstructions. The methodology relies on three main features. First, an optimized HARDI reconstruction technique based on the generalized q-sampling imaging approach is adopted. Second, directional statistics are used to estimate orientation distribution function (ODF) profile directions from data distributed on the unit sphere. Third, a modified streamline algorithm able to accommodate multiple fiber tracts and multiple orientations per voxel is used, to exploit the directional information gathered from estimated ODF profiles. The methodology has been tested on synthetic data simulations of crossing fibers and on a real data set.


Lobo L.S.,New University of Lisbon
Reaction Kinetics, Mechanisms and Catalysis | Year: 2016

Understanding stable carbon formation mechanisms requires isothermal kinetic studies. Distinguishing preliminary solid-state changes from the prevailing steady-state (sustained) carbon formation route is essential. The three alternative kinetic routes for carbon formation are clarified: dual catalyst route, gas phase pyrolysis and hybrid route—a combination of the two previous ones. When kinetic linearity is observed in a reaction involving catalytic formation or gasification of a solid, this is evidence that only a steady-state carbon diffusion process is operating obeying Fick’s 1st law in a stable geometry. Fick’s 2nd law rules in the initial transition stage, involving nucleation and solid-state reaction processes. Catalyst duality is discussed, considering the roles played by the two distinct surface regions between which the bulk carbon flux is maintained during steady-state reaction. © 2016 Akadémiai Kiadó, Budapest, Hungary


Schnian G.,Charite - Medical University of Berlin | Kuhls K.,Charite - Medical University of Berlin | Mauricio I.L.,London School of Hygiene and Tropical Medicine | Mauricio I.L.,New University of Lisbon
Parasitology | Year: 2011

Molecular approaches are being used increasingly for epidemiological studies of visceral and cutaneous leishmaniases. Several molecular markers resolving genetic differences between Leishmania parasites at species and strain levels have been developed to address key epidemiological and population genetic questions. The current gold standard, multilocus enzyme typing (MLEE), needs cultured parasites and lacks discriminatory power. PCR assays identifying species directly with clinical samples have proven useful in numerous field studies. Multilocus sequence typing (MLST) is potentially the most powerful phylogenetic approach and will, most probably, replace MLEE in the future. Multilocus microsatellite typing (MLMT) is able to discriminate below the zymodeme level and seems to be the best candidate for becoming the gold standard for distinction of strains. Population genetic studies by MLMT revealed geographical and hierarchic population structure in L. tropica, L. major and the L. donovani complex. The existence of hybrids and gene flow between Leishmania populations suggests that sexual recombination is more frequent than previously thought. However, typing and analytical tools need to be further improved. Accessible databases should be created and sustained for integrating data obtained by different researchers. This would allow for global analyses and help to avoid biases in analyses due to small sample sizes. © 2010 Cambridge University Press.


Silva I.,Servico Of Reumatologia Do Centro Hospitalar Of Lisbon Ocidental | Branco J.C.,Servico Of Reumatologia Do Centro Hospitalar Of Lisbon Ocidental | Branco J.C.,New University of Lisbon
Acta Reumatologica Portuguesa | Year: 2011

The discovery of the receptor activator of nuclear factor-kB (RANK)/RANK Ligand (RANKL)/osteoprotegerin (OPG) pathway contributed to the understanding of how bone formation and resorption were processed and regulated. RANKL and OPG are members of the tumor necrosis factor (TNF) and TNF receptor (TNFr) superfamilies, respectively, and binding to receptor activator of NF-kB (RANK) not only regulate osteoclast formation, activation and survival in normal bone modeling and remodeling, but also in several other pathologic conditions characterized by increased bone turnover. There is accumulating evidence of the potential role of OPG and RANKL in other tissues. Looking beyond the RANK/RANKL/OPG axis, Wingless (Wnt) pathway emerged as the osteoblast differentiation way, and also as a bone mass regulator. Researchers have been discovering new molecules and cytokines interactions. Altogether, data suggest that RANK/RANKL/OPG system could be targeted as a new treatment strategy in bone conditions. FREEDOM is the more recently published clinical trial about a RANKL-specific recombinant fully human monoclonal antibody (denosumab). OPG is also a potential innovative therapeutic option to be investigated.


Machuqueiro M.,University of Lisbon | Baptista A.M.,New University of Lisbon
Proteins: Structure, Function and Bioinformatics | Year: 2011

In this study, we investigate two factors that can hinder the performance of constant-pH molecular dynamics methods in predicting protein pK a values, using hen egg white lysozyme as a test system. The first factor is related to the molecular definition and pK a value of model compounds in the Poisson-Boltzmann framework. We address this by defining the model compound as a molecular fragment with an associated pK a value that is calibrated against experimental data, which results in a decrease of 0.12 units in pK a errors. The second addressed factor is the possibility that detrimental structural distortions are being introduced in the simulations by the underlying molecular mechanics force field. This issue is investigated by analyzing how the gradual structural rearrangements affect the predicted pK a values. The two GROMOS force fields studied here (43A1 and 53A6) yield good pK a predictions, although a time-dependent performance is observed: 43A1 performs better after a few nanoseconds of structural reorganization (pK a errors of ~0.45), while 53A6 gives the best prediction right at the first nanosecond (pK a errors of 0.42). These results suggest that the good performance of constant-pH molecular dynamics methods could be further improved if these force field limitations were overcome. © 2011 Wiley-Liss, Inc.


Fernandes H.L.,Northwestern University | Fernandes H.L.,Instituto Gulbenkian Of Ciencia | Fernandes H.L.,New University of Lisbon | Stevenson I.H.,University of California at Berkeley | And 2 more authors.
Journal of Neuroscience | Year: 2014

Bayesian statistics defines how new information, given by a likelihood, should be combined with previously acquired information, given by a prior distribution. Many experiments have shown that humans make use of such priors in cognitive, perceptual, and motor tasks, but where do priors come from? As people never experience the same situation twice, they can only construct priors by generalizing from similar past experiences. Here we examine the generalization of priors over stochastic visuomotor perturbations in reaching experiments. In particular, we look into how the first two moments of the prior-the mean and variance (uncertainty)-generalize. We find that uncertainty appears to generalize differently from the mean of the prior, and an interesting asymmetry arises when the mean and the uncertainty are manipulated simultaneously. © 2014 the authors.


Riguzzi F.,University of Ferrara | Swift T.,New University of Lisbon
ACM Transactions on Computational Logic | Year: 2014

As evaluation methods for logic programs have become more sophisticated, the classes of programs for which termination can be guaranteed have expanded. From the perspective of ar set programs that include function symbols, recent work has identified classes for which grounding routines can terminate either on the entire program [Calimeri et al. 2008] or on suitable queries [Baselice et al. 2009]. From the perspective of tabling, it has long been known that a tabling technique called subgoal abstraction provides good termination properties for definite programs [Tamaki and Sato 1986] and this result was recently extended to stratified programs via the class of bounded term-size programs [Riguzzi and Swift 2013]. In this article, we provide a formal definition of tabling with subgoal abstraction resulting in the SLGSA algorithm. Moreover, we discuss a declarative characterization of the queries and programs for which SLGSA terminates. We call this class strongly bounded term-size programs and show its equivalence to programs with finite well-founded models. For normal programs, strongly bounded term-size programs strictly includes the finitely ground programs of Calimeri et al. [2008]. SLGSA has an asymptotic complexity on strongly bounded term-size programs equal to the best known and produces a residual program that can be sent to an answer set programming system. Finally, we describe the implementation of subgoal abstraction within the SLG-WAM of XSB and provide performance results. © 2014 ACM.


Nogueira H.I.S.,University of Coimbra | Adduce C.,Third University of Rome | Alves E.,National Laboratory for Civil Engineering | Franca M.J.,New University of Lisbon
Journal of Hydraulic Research | Year: 2013

Gravity currents produced by full-depth lock-release of saline water into a fresh water tank are studied focusing on the influence of the initial density of the saline mixture in the lock and the bed roughness on gravity current kinematics. Temporal evolution of the current front position and front velocity are analysed and related to different phases of the current. Time-space evolution of current depth-averaged density and current height are assessed as well. Roughness of the channel bed plays an important role in the current kinematics, particularly in decreasing the front velocity due to extra drag at the bed. The analysis of Froude numbers, estimated with the initial and local reduced gravity and established with different length scales of the current, allow for the definition of the important variables and current dynamics of each phase of the current development. © 2013 Copyright International Association for Hydro-Environment Engineering and Research.


Ponnusamy R.,Karolinska Institutet | Ponnusamy R.,New University of Lisbon | Lohkamp B.,Karolinska Institutet
Journal of Neurochemistry | Year: 2013

Collapsin response mediator protein-5 (CRMP-5) is the latest identified member of the CRMP cytosolic phosphoprotein family, which is crucial for neuronal development and repair. CRMPs exist as homo- and/or hetero-tetramers in vivo and participate in signaling transduction, cytoskeleton rearrangements, and endocytosis. CRMP-5 antagonizes many of the other CRMPs' functions either by directly interacting with them or by competing for their binding partners. We determined the crystal structures of a full length and a truncated version of human CRMP-5, both of which form a homo-tetramer similar to those observed in CRMP-1 and CRMP-2. However, solution studies indicate that CRMP-5 and CRMP-1 form weaker homo-tetramers compared with CRMP-2, and that divalent cations, Ca2+ and Mg2+, destabilize oligomers of CRMP-5 and CRMP-1, but promote CRMP-2 oligomerization. On the basis of comparative analysis of the CRMP-5 crystal structure, we identified residues that are crucial for determining the preference for hetero-oligomer or homo-oligomer formation. We also show that in spite of being the CRMP family member most closely related to dihydropyrimidinase, CRMP-5 does not have any detectable amidohydrolase activity. The presented findings provide new detailed insights into the structure, oligomerization, and regulation of CRMPs. Insights into the oligomerization of CRMPs: Crystal structure of human collapsin response mediator protein 5. Collapsin response mediator proteins (CRMPs) are cytosolic homo- and/or hetero-tetrameric phosphoproteins crucial for neuronal development and repair. We determined the crystal structure of human CRMP-5, revealing a homo-tetramer assembly similar to that of other CRMPs. Solution studies indicate that subunit interactions in CRMP-5 and CRMP-1 homo-tetramers are weaker compared with CRMP-2, and that divalent cations, Ca2+ and Mg 2+, destabilize them further. Read the Editorial Highlight for this article on doi: 10.1111/jnc.12224. © 2013 International Society for Neurochemistry.


Carlos Lima J.,New University of Lisbon | Rodriguez L.,University of Barcelona
Chemical Society Reviews | Year: 2011

Gold(i) alkynyl complexes present a growing research field with respect to their very wide range of applications in different areas such as luminescence, molecular recognition, optical switches, electronics and catalysis. Biological applications are also being developed in the recent years, where these complexes are used as therapeutic agents against different illnesses such as cancer cells or malaria. Related to luminescence, a general overview of the different states responsible for the observed emission is also included in this critical review. In some cases, the assignment is complicated due to the influence of the gold(i) atom and its capability to form metal⋯metal interactions (aurophilicity). Although an extensive discussion has been found in the literature related to the luminescent properties of these complexes, to the best of our knowledge there are not reports covering the span of their very interesting applications. The widespread research fields where this kind of complexes could present a key role is presented in this review (119 references). © 2011 The Royal Society of Chemistry.


Almeida Santos C.V.,New University of Lisbon
Synlett | Year: 2014

(A) The Reformatsky-type reaction of 1 with (E)-N-benzyl-1- phenylmethanimine (7), mediated by diethylzinc, was performedto achieve a chemo- and diastereoselective synthesis of the -bromo--fluoro-lactam 8 in 76% yield as a single diastereomer, withsyn configuration between the hydrogen and fluorine atom.8. © Georg Thieme Verlag Stuttgart New York.


Figueiras A.,New University of Lisbon
Proceedings of the International Conference on Information Visualisation | Year: 2015

Over the past few years the web has been responsible for the rise in popularity of visualizations and it seems that interactive or playable visualizations have become more popular and end up standing out more. The use of interactivity and animation has been extensively discussed in information visualization research, but there has been some controversy in relation to its benefits. Additionally, there is still little empirical evidence about its efficacy in terms of improving understanding of the data and there is few research that points out guidelines of how to incorporate it successfully and that proves that playable visualizations are indeed more enjoyable and popular among users. In order to guide future research on the actual benefits of interactivity in visualization it is important to understand what types of interactivity are currently being used in the field and to have a framework to help discuss and evaluate interaction techniques. After conducting an extensive review of popular visualizations and their interactive capabilities, we propose eleven categories of interaction techniques: filtering, selecting, abstract/elaborate, overview and explore, connect/relate, history, extraction of features, reconfigure, encode, participation/collaboration, and gamification. © 2015 IEEE.


Amaral L.,New University of Lisbon | Molnar J.,University of Szeged
Pharmaceuticals | Year: 2012

This mini-review provides the entire experimental history of the development of the old neuroleptic thioridazine (TZ) for therapy of antibiotic resistant pulmonary tuberculosis infections. TZ is effective when used in combination with antibiotics to which the initial Mycobacterium tuberculosis was resistant. Under proper cardiac evaluation procedures, the use of TZ is safe and does not produce known cardiopathy such as prolongation of QT interval. Because TZ is cheap, it should be considered for therapy of XDR and TDR-Mtb patients in economically disadvantaged countries. © 2012 by the authors; licensee MDPI, Basel, Switzerland.


Magin R.,University of Illinois at Chicago | Ortigueira M.D.,New University of Lisbon | Podlubny I.,Technical University of Kosice | Trujillo J.,University of La Laguna
Signal Processing | Year: 2011

A look into fractional calculus and its applications from the signal processing point of view is done in this paper. A coherent approach to the fractional derivative is presented, leading to notions that are not only compatible with the classic but also constitute a true generalization. This means that the classic are recovered when the fractional domain is left. This happens in particular with the impulse response and transfer function. An interesting feature of the systems is the causality that the fractional derivative imposes. The main properties of the derivatives and their representations are presented. A brief and general study of the fractional linear systems is done, by showing how to compute the impulse, step and frequency responses, how to test the stability and how to insert the initial conditions. The practical realization problem is focussed and it is shown how to perform the inputouput computations. Some biomedical applications are described. © 2010 Elsevier B.V. All rights reserved.


Bianchi A.,University of Florence | Delgado-Pinar E.,University of Valencia | Garcia-Espana E.,University of Valencia | Giorgi C.,University of Florence | Pina F.,New University of Lisbon
Coordination Chemistry Reviews | Year: 2013

Selected metal complexes behaving as photochemical switches, mostly operating by light emission/absorption without the intervention of any added chemical species, are reviewed. First, the switching mechanisms are analyzed to offer readers an easier understanding of the described systems. Examples of photochemical switching based on complexation/decomplexation processes and photo-bistable systems, comprising metal complexes with azobenzene, azopyridine, diarylethene, spirocyclic and rhodamine ligands, make the central body of the review. These examples were chosen to provide an overview of the evolution of metal-ion based photochemical switches, collecting together historical cases and more recent systems mainly reported in the last 15 years. © 2013 Elsevier B.V.


Phillips A.M.F.,New University of Lisbon
Mini-Reviews in Organic Chemistry | Year: 2014

Chiral phosphonates find many applications in medicine, agriculture, materials science and also in organic synthesis. The rapid growth of asymmetric organocatalysis in the last decade has sparkled the interest of organophosphorus chemists, and a wealth of new methodologies to obtain chiral phosphonic acid derivatives has been developed in recent years. This review surveys the last five years, and it includes methodology to synthesize hydroxyphosphonates, aminophosphonates, asymmetric aldol reactions and Michael addition reactions, cycloadditions and domino processes, as well as applications in target-oriented synthesis involving the Horner-Wadsworth-Emmons olefination reaction and the use of chiral phosphonates as acylating agents. © 2014 Bentham Science Publishers.


Riguzzi F.,University of Ferrara | Swift T.,New University of Lisbon
Theory and Practice of Logic Programming | Year: 2011

Many real world domains require the representation of a measure of uncertainty. The most common such representation is probability, and the combination of probability with logic programs has given rise to the field of Probabilistic Logic Programming (PLP), leading to languages such as the Independent Choice Logic, Logic Programs with Annotated Disjunctions (LPADs), Problog, PRISM, and others. These languages share a similar distribution semantics, and methods have been devised to translate programs between these languages. The complexity of computing the probability of queries to these general PLP programs is very high due to the need to combine the probabilities of explanations that may not be exclusive. As one alternative, the PRISM system reduces the complexity of query answering by restricting the form of programs it can evaluate. As an entirely different alternative, Possibilistic Logic Programs adopt a simpler metric of uncertainty than probability. Each of these approaches'general PLP, restricted PLP, and Possibilistic Logic Programming'can be useful in different domains depending on the form of uncertainty to be represented, on the form of programs needed to model problems, and on the scale of the problems to be solved. In this paper, we show how the PITA system, which originally supported the general PLP language of LPADs, can also efficiently support restricted PLP and Possibilistic Logic Programs. PITA relies on tabling with answer subsumption and consists of a transformation along with an API for library functions that interface with answer subsumption. We show that, by adapting its transformation and library functions, PITA can be parameterized to PITA(IND, EXC) which supports the restricted PLP of PRISM, including optimizations that reduce non-discriminating arguments and the computation of Viterbi paths. Furthermore, we show PITA to be competitive with PRISM for complex queries to Hidden Markov Model examples, and sometimes much faster. We further show how PITA can be parameterized to PITA(COUNT) which computes the number of different explanations for a subgoal, and to PITA(POSS) which scalably implements Possibilistic Logic Programming. PITA is a supported package in version 3.3 of XSB. © 2011 Cambridge University Press.


Nobre A.M.,New University of Lisbon | Nobre A.M.,SIMTEJO Saneamento Integrado dos Municipios do Tejo e Trancao SA
Marine Ecology Progress Series | Year: 2011

Anthropogenic activity has a negative impact on many coastal ecosystems, compromising the significant direct and indirect socio-economic benefits provided in these areas. Maintaining activities that depend on coastal zones while preserving the ecological state of the ecosystems represents a management challenge. Management of coastal zones requires scientifically based knowledge, due to the complexity of the ecological processes which occur in these ecosystems and because of interaction with the socio-economic system. The effectiveness of coastal management instruments and programmes needs to be evaluated to determine the success of adopted measures and to establish improved goals. Some of the research areas that can support coastal management include marine spatial planning, ecological modelling, development of tools to communicate science to managers, and interaction between coastal ecosystems and socio-economics. This paper reviews management instruments to address coastal zone problems and of some research areas to support management. © Inter-Research 2011.


Couch Y.,University of Oxford | Anthony D.C.,University of Oxford | Dolgov O.,Max Planck Institute for Biophysical Chemistry | Dolgov O.,Russian Academy of Medical Sciences | And 5 more authors.
Brain, Behavior, and Immunity | Year: 2013

A chronic stress paradigm comprising exposure to predation, tail suspension and restraint induces a depressive syndrome in C57BL/6J mice that occurs in some, but not all, animals. Here, we sought to extend our behavioural studies to investigate how susceptibility (sucrose preference<65%) or resilience (sucrose preference>65%) to stress-induced anhedonia affects the 5HT system and the expression of inflammation-related genes. All chronically stressed animals, displayed increased level of anxiety, but susceptible mice exhibited an increased propensity to float in the forced swim test and demonstrate hyperactivity under stressful lighting conditions. These changes were not present in resilient or acutely stressed animals. Compared to resilient animals, susceptible mice showed elevated expression of tumour necrosis factor alpha (TNF) and the 5-HT transporter (SERT) in the pre-frontal area. Enhanced expression of 5HT2A and COX-1 in the pre-frontal area was observed in all stressed animals. In turn, indoleamine-2,3-dioxygenase (IDO) was significantly unregulated in the raphe of susceptible animals. At the cellular level, increased numbers of Iba-1-positive microglial cells were also present in the prefrontal area of susceptible animals compared to resilient animals. Consequently, the susceptible animals display a unique molecular profile when compared to resilient, but anxious, animals. Unexpectedly, this altered profile provides a rationale for exploring anti-inflammatory, and possibly, TNF-targeted therapy for major depression. © 2013 Elsevier Inc.


Ramos T.R.P.,Iscte Business School Instituto Universitario Of Lisbon Iscte Iul | Ramos T.R.P.,University of Lisbon | Gomes M.I.,New University of Lisbon | Barbosa-Povoa A.P.,University of Lisbon
Waste Management | Year: 2013

This research has been motivated by a real-life problem of a waste cooking oil collection system characterized by the existence of multiple depots with an outsourced vehicle fleet, where the collection routes have to be plan. The routing problem addressed allows open routes between depots, i.e., all routes start at one depot but can end at the same or at a different one, depending on what minimizes the objective function considered. Such problem is referred as a Multi-Depot Vehicle Routing Problem with Mixed Closed and Open Inter-Depot Routes and is, in this paper, modeled through a mixed integer linear programming (MILP) formulation where capacity and duration constraints are taken into account. The model developed is applied to the real case study providing, as final results, the vehicle routes planning where a decrease of 13% on mileage and 11% on fleet hiring cost are achieved, when comparing with the current company solution. © 2013 Elsevier Ltd.


de Sousa J.D.,Rega Institute for Medical Research | Muller V.,Eotvos Lorand University | Lemey P.,Rega Institute for Medical Research | Vandamme A.-M.,Rega Institute for Medical Research | Vandamme A.-M.,New University of Lisbon
PLoS ONE | Year: 2010

The processes that permitted a few SIV strains to emerge epidemically as HIV groups remain elusive. Paradigmatic theories propose factors that may have facilitated adaptation to the human host (e.g., unsafe injections), none of which provide a coherent explanation for the timing, geographical origin, and scarcity of epidemic HIV strains. Our updated molecular clock analyses established relatively narrow time intervals (roughly 1880-1940) for major SIV transfers to humans. Factors that could favor HIV emergence in this time frame may have been genital ulcer disease (GUD), resulting in high HIV-1 transmissibility (4-43%), largely exceeding parenteral transmissibility; lack of male circumcision increasing male HIV infection risk; and gender-skewed city growth increasing sexual promiscuity. We surveyed colonial medical literature reporting incidences of GUD for the relevant regions, concentrating on cities, suffering less reporting biases than rural areas. Coinciding in time with the origin of the major HIV groups, colonial cities showed intense GUD outbreaks with incidences 1.5-2.5 orders of magnitude higher than in mid 20th century. We surveyed ethnographic literature, and concluded that male circumcision frequencies were lower in early 20th century than nowadays, with low rates correlating spatially with the emergence of HIV groups. We developed computer simulations to model the early spread of HIV-1 group M in Kinshasa before, during and after the estimated origin of the virus, using parameters derived from the colonial literature. These confirmed that the early 20th century was particularly permissive for the emergence of HIV by heterosexual transmission. The strongest potential facilitating factor was high GUD levels. Remarkably, the direct effects of city population size and circumcision frequency seemed relatively small. Our results suggest that intense GUD in promiscuous urban communities was the main factor driving HIV emergence. Low circumcision rates may have played a role, probably by their indirect effects on GUD. © 2010 Sousa et al.


Pais D.,New University of Lisbon | Moxham B.J.,University of Cardiff
European Journal of Anatomy | Year: 2013

While the teaching of gross anatomy remains a topic of considerable discussion (and occasional controversy), in terms of the time allocated, timing within the course, content and clinical relevance, and the use of cadavers and dissection by students, there is relatively little discourse about whether gross anatomy should be taught systemically and/or regionally or whether anatomy should be integrated or a stand-alone course. This brief article analyses the differences between the systemic and region approaches, suggests ways in which the efficacy of these approaches might be investigated, and assesses how they might be integrated into other biomedical sciences and into clinical disciplines. Overall, we conclude that, even within health care studies courses such as medicine that are integrated, there should be a standalone component for the study of gross anatomy that takes a regional approach; although undoubtedly study of anatomy both systemically and regionally would be the ideal situation (time and resources permitting).


Costa A.C.,New University of Lisbon
Advances in Geosciences | Year: 2011

This paper analyzes the yearly changes in precipitation from 1940 to 1999 on local and regional scales over the southern region of continental Portugal, which has large areas threatened by desertification. The Standard Precipitation Index (SPI) time series with the 12-month time scale is calculated for 43 meteorological stations. A geostatistical approach is used to evaluate the temporal dynamics of the spatial patterns of precipitation. The spatial homogeneity of the SPI is evaluated for each decade. Afterwards, a geostatistical simulation algorithm (direct sequential simulation) is used to produce 100 equiprobable maps of the SPI for each year. This gridded data set (6000 maps with 800 m × 800 m grid cells) is then used to produce yearly scenarios of the SPI from 1940 to 1999, and uncertainty evaluations of the produced scenarios. The linear trend of SPI values over the sixty years period is calculated at each grid cell of the scenarios' maps using a nonparametric estimator. Wilcoxon-Mann-Whitney one-sided tests are used to compare the local median of the SPI in 1940/1969 with its median in 1970/1999. Results show that moderate drought conditions occur frequently over the study region, except in the northwest coast. Severe drought frequency patterns are found in areas of the centre and southeast regions. A significant trend towards drying occurs in the centre region and in the northeast. Considering the amount of water consumption and irrigation already required in some municipalities, water shortage due to drought is a viable threat in most of the Alentejo region if those local trends persist. © Author(s) 2011.


Fernao Pires V.,Polytechnic Institute of Setubal | Fernao Pires V.,Center for Innovation in Electric and Energy Engineering | Martins J.F.,New University of Lisbon | Hao C.,China University of Mining and Technology
Solar Energy | Year: 2012

A fast and robust control strategy for a multilevel inverter in grid-connected photovoltaic system is presented. The multilevel inverter is based on a dual two-level inverter topology. There are two isolated PV generators that feeding each bridge inverter. The output of each inverter is connected to a three-phase transformer. The active and reactive powers flowing into the grid are controlled by a sliding mode algorithm. An alfa-beta space vector modulator is also used. The inverters DC voltages are also controller by a sliding mode controller. In this way, a fast and robust system controller is obtained. Several test results are presented in order to verify the effectiveness of the proposed system controller. © 2012 Elsevier Ltd.


Amaral P.,New University of Lisbon | Pais T.C.,University of Nottingham
Computers and Operations Research | Year: 2016

University examination scheduling is a difficult and heavily administrative task, particularly when the number of students and courses is high. Changes in educational paradigms, an increase in the number of students, the aggregation of schools, more flexible curricula, among others, are responsible for an increase in the difficulty of the problem. As a consequence, there is a continuous demand for new and more efficient approaches. Optimisation and Constraint Programming communities have devoted considerable attention to this difficult problem. Just the definition of a satisfactory, not to mention optimal, timetabling may be complex. In fact, to characterise a timetabling solution, a single criteria may not be enough, since what may be considered good for one group of students may be regarded inappropriate for other students, or teachers. In this paper, four criteria were used to characterise the spreading of the exams over the examination period. A set of constraints regarding the non-overlapping of exams with students in common was considered. A multi-objective optimisation program was used to handle the four criteria and a Tabu Search was implemented to find a good feasible solution for this problem. Two new features to increase the automation of the algorithm were proposed. First, it uses a Fuzzy Inference Ruled Based System to choose the tabu tenure of the elements in the tabu list. Secondly, a modified version of the Compromise Ratio (CR) is proposed, where the usual fixed weights are replaced by weighting functions to rank the neighbourhood solutions in each iteration. Sufficient conditions which guarantee the monotonicity of the weighting functions are presented. © 2016 Elsevier Ltd. All rights reserved.


Camacho R.J.,New University of Lisbon | Camacho R.J.,Centro Hospitalar Of Lisbon Ocidental
Intervirology | Year: 2012

HIV-2 is responsible for a limited epidemic in West Africa. Around 20% of all infected patients will progress to AIDS, and will need antiretroviral therapy. Unfortunately, antiretrovirals were developed to suppress HIV-1 replication; not all of them are active against HIV-2, e.g. all nonnucleoside reverse transcriptase inhibitors or fusion inhibitors. Moreover, only three protease inhibitors have the same activity in HIV-1 and HIV-2: lopinavir, saquinavir and darunavir. Even if all nucleoside and nucleotide reverse transcriptase inhibitors appear to be equally efficient against HIV-2, different resistance pathways and an increased facility of resistance selection make their use much more difficult than in HIV-1. Integrase inhibitors have a potent inhibitory effect on HIV-2 replication, but questions about the best timing for their use remain unanswered, as well as those regarding the use of entry inhibitors in this setting. The lack of reliable monitoring tools adds to the difficulty of treating HIV-2-infected patients, mostly because the viral load is not as useful as it is in HIV-1, and the incomplete knowledge about resistance pathways limits the clinical usefulness of resistance testing. With all these limitations, HIV-2 treatment remains a challenge. Further research is urgently needed, since antiretroviral therapy is now becoming available in countries where the HIV-2 prevalence is significant. The need for appropriate guidelines for HIV-2 treatment has become an emergency. Copyright © 2012 S. Karger AG, Basel.


Branco J.C.,New University of Lisbon
Acta reumatológica portuguesa | Year: 2010

Fibromyalgia syndrome (FMS) is a very prevalent disorder defined by the presence of hyperalgesia and allodynia that leads to musculoskeletal chronic pain very frequently associated with fatigue and a diversity of other symptoms. The cause of FMS is unknown and its pathogenesis is complex and not well understood. This paper will rather discuss central pain mechanisms and the role of stressors and other factors as triggering events for onset of clinical manifestations.


Nunes R.,University of Lisbon | Almeida J.A.,New University of Lisbon
Computers and Geosciences | Year: 2010

Improving the performance and robustness of algorithms on new high-performance parallel computing architectures is a key issue in efficiently performing 2D and 3D studies with large amount of data. In geostatistics, sequential simulation algorithms are good candidates for parallelization. When compared with other computational applications in geosciences (such as fluid flow simulators), sequential simulation software is not extremely computationally intensive, but parallelization can make it more efficient and creates alternatives for its integration in inverse modelling approaches.This paper describes the implementation and benchmarking of a parallel version of the three classic sequential simulation algorithms: direct sequential simulation (DSS), sequential indicator simulation (SIS) and sequential Gaussian simulation (SGS). For this purpose, the source used was GSLIB, but the entire code was extensively modified to take into account the parallelization approach and was also rewritten in the C programming language. The paper also explains in detail the parallelization strategy and the main modifications. Regarding the integration of secondary information, the DSS algorithm is able to perform simple kriging with local means, kriging with an external drift and collocated cokriging with both local and global correlations. SIS includes a local correction of probabilities. Finally, a brief comparison is presented of simulation results using one, two and four processors. All performance tests were carried out on 2D soil data samples. The source code is completely open source and easy to read. It should be noted that the code is only fully compatible with Microsoft Visual C and should be adapted for other systems/compilers. © 2010 Elsevier Ltd.


Loureiro M.I.G.,New University of Lisbon | Freudenberg N.,York College - The City University of New York
Family Practice | Year: 2012

Background: Reducing rates of child obesity requires an approach that transcends the medicalization of overweight. Family practice doctors and public health professionals need to work with other sectors to establish comprehensive approaches to obesity reduction. Objectives: This study compares the approaches of three cities with different health and political systems (Lisbon, London and New York City) to promoting effective action to decrease child obesity. Methods: Using a comparative case study approach, participant observers in three intersectoral municipal collaborative on child obesity describe their challenges and accomplishments. Results: Municipal governments made child obesity a policy priority and coordinate efforts in different sectors. Public health provided relevant information on population characteristics and scientific evidence for decision-making, family practice monitored children's growth and assisted families to adopt healthy behaviors. These sectors, together with university-based researchers, also played an advocacy role, addressing inequalities, alerting the public and policy makers about damaging products or risky situations, and regulating private interests that threaten well-being, e.g., the food and beverage industry that promotes unhealthy products. Local, national and global networks of health providers, municipal agencies and researchers have helped to diagnose problems, coordinate action across sectors and levels, share and evaluate successes and failures, translate evidence into practice and promote social cohesion. Conclusions: These cities have developed common approaches and face similar challenges in reducing high rates of child obesity, suggesting that it may be possible for cities in different parts of the world to learn from each other and thus accelerate progress. © The Author 2012. Published by Oxford University Press. All rights reserved.


Barros P.P.,New University of Lisbon
Hygiea Internationalis | Year: 2016

Tobacco consumption is seen as a public health issue in many countries, leading to policies aimed at consumption cessation and to prevent the start of a regular smoking habit in the young. We assess the association between smoking habits and health status in a sample of Portuguese population with 50 years and above, from the SHARE – Survey of Health, Age and Retirement in Europe wave 4. Using a physical measure of health, respiratory peak flow, as well as the more standard measures of medical-doctor-diagnosed respiratory problems and self-assessed health, we show that tobacco consumption has an important negative impact in the health of the elderly, which is not captured by self-assessed health. From a policy perspective, this advises to the routine collection of physical measures of health to have effective knowledge about the health of the population and appropriate design in interventions. © Hygiea Internationalis 1999-2016.


Goncalves Coelho P.,New University of Lisbon | Rui Fernandes P.,University of Lisbon | Carrico Rodrigues H.,University of Lisbon
Journal of Biomechanics | Year: 2011

Natural biological materials usually present a hierarchical arrangement with various structural levels. The biomechanical behavior of the complex hierarchical structure of bone is investigated with models that address the various levels corresponding to different scales. Models that simulate the bone remodeling process concurrently at different scales are in development. We present a multiscale model for bone tissue adaptation that considers the two top levels, whole bone and trabecular architecture. The bone density distribution is calculated at the macroscale (whole bone) level, and the trabecular structure at the microscale level takes into account its mechanical properties as well as surface density and permeability. The bone remodeling process is thus formulated as a material distribution problem at both scales. At the local level, the biologically driven information of surface density and permeability characterizes the trabecular structure. The model is tested by a three-dimensional simulation of bone tissue adaptation for the human femur. The density distribution of the model shows good agreement with the actual bone density distribution. Permeability at the microstructural level assures interconnectivity of pores, which mimics the interconnectivity of trabecular bone essential for vascularization and transport of nutrients. The importance of this multiscale model relays on the flexibility to control the morphometric parameters that characterize the trabecular structure. Therefore, the presented model can be a valuable tool to define bone quality, to assist with diagnosis of osteoporosis, and to support the development of bone substitutes. © 2010 Elsevier Ltd.


Ermida G.,New University of Lisbon
Polar Record | Year: 2016

At least four littoral countries have Arctic strategies that address energy issues. However, US, Canada, Russia and Norway strategies up to 2020 and beyond, reveal different interests in exploring Arctic resources. While Arctic oil and gas are of strategic importance to Russia and to Norway, Canada and the US seem content with continuing their current extraction predominantly south of the Arctic Circle. Despite the different approaches, the outcomes seem strangely similar. Indeed, despite the hype concerning the Arctic in the last decade, and for very diverse reasons, it is unlikely that any of these four countries will increase hydrocarbon production in the Arctic during the period under analysis. This was true even before the recent drop in oil prices. For all its potential, it is unclear what lies ahead for the region. Copyright © Cambridge University Press 2015.


Riguzzi F.,University of Ferrara | Swift T.,New University of Lisbon
Leibniz International Proceedings in Informatics, LIPIcs | Year: 2010

The paper presents the algorithm \Probabilistic Inference with Tabling and Answer subsumption" (PITA) for computing the probability of queries from Logic Pro- grams with Annotated Disjunctions. PITA is based on a program transformation techniques that adds an extra argument to every atom. PITA uses tabling for saving intermediate results and answer subsumption for combining different answers for the same subgoal. PITA has been implemented in XSB and compared with the ProbLog, cplint and CVE systems. The results show that in almost all cases, PITA is able to solve larger problems and is faster than competing algorithms.


Gabaldon A.,New University of Lisbon
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2011

In this work we consider how to enforce norms in the Situation Calculus based programming language Golog and its relatives. We define a notion of norm compliant sequence of actions with respect to norms prescribing some actions to be forbidden or obliged (ought-to-do norms), norms prescribing that a state-condition is forbidden (ought-to-be norms) and norms that are a form of deadline. We then show a procedure that allows incorporating the norms into the underlying action theory so that after this is done, the agent's behavior is guaranteed to be norm compliant. © 2011 Springer-Verlag Berlin Heidelberg.


Amarante dos Santos F.,New University of Lisbon
Structural Control and Health Monitoring | Year: 2016

The present paper studies the feasibility, through physical experimentation, of efficient and low-cost macrostrain sensors, based on shape-memory alloy technologies. The motivation of this work is to explore the intrinsic relation between electrical resistivity and strain, associated with the development of the stress induced martensitic transformation in superelastic shape-memory alloys. This property enables the material to endure deformations up to 8% without any residual strains, making shape-memory alloy wires excellent candidates for kernel elements in innovative strain transducers with dynamic ranges 4 to 5 times larger than the currently available strain transducers. An experimental prototype of a beam with a set of SMA macrostrain sensors is presented, featuring a timed scanning sequential algorithm to successfully perform the resistance readings. The aim of this work is to provide an additional insight into the potential of SMAs in new macrostrain measurement applications. © 2016 John Wiley & Sons, Ltd.


Martins R.,University of Algarve | Bugalho M.J.,Instituto Portugues Of Oncologia Of Lisbon Francisco Gentil Epe | Bugalho M.J.,New University of Lisbon
International Journal of Endocrinology | Year: 2014

Paragangliomas are rare neuroendocrine tumors that arise in the sympathetic or parasympathetic nervous system. Sympathetic paragangliomas are mainly found in the adrenal medulla (designated pheochromocytomas) but may also have a thoracic, abdominal, or pelvic localization. Parasympathetic paragangliomas are generally located at the head or neck. Knowledge concerning the familial forms of paragangliomas has greatly improved in recent years. Additionally to the genes involved in the classical syndromic forms: VHL gene (von Hippel-Lindau), RET gene (Multiple Endocrine Neoplasia type 2), and NF1 gene (Neurofibromatosis type 1), 10 novel genes have so far been implicated in the occurrence of paragangliomas/pheochromocytomas: SDHA, SDHB, SDHC, SDHD, SDHAF2, TMEM127, MAX, EGLN1, HIF2A, and KIF1B. It is currently accepted that about 35% of the paragangliomas cases are due to germline mutations in one of these genes. Furthermore, somatic mutations of RET, VHL, NF1, MAX, HIF2A, and H-RAS can also be detected. The identification of the mutation responsible for the paraganglioma/pheochromocytoma phenotype in a patient may be crucial in determining the treatment and allowing specific follow-up guidelines, ultimately leading to a better prognosis. Herein, we summarize the most relevant aspects regarding the genetics and clinical aspects of the syndromic and nonsyndromic forms of pheochromocytoma/paraganglioma aiming to provide an algorithm for genetic testing. © 2014 Rute Martins and Maria João Bugalho.


De Freitas J.A.T.,University of Lisbon | Moldovan I.D.,Catholic University of Portugal | Cismasiu C.,New University of Lisbon
Computational Mechanics | Year: 2011

The elastodynamic response of saturated poroelastic media is modelled approximating independently the solid and seepage displacements in the domain and the force and pressure components on the boundary of the element. The domain and boundary approximation bases are used to enforce on average the dynamic equilibrium and the displacement continuity conditions, respectively. The resulting solving system is Hermitian, except for the damping term, and its coefficients are defined by boundary integral expressions as a Trefftz basis is used to set up the domain approximation. This basis is taken from the solution set of the governing differential equation and models the free-field elastodynamic response of the medium. This option justifies the relatively high levels of performance that are illustrated with the time domain analysis of unbounded domains. © 2011 Springer-Verlag.


Noronha P.,New University of Lisbon
Leonardo | Year: 2011

The author works with microorganisms that produce colored natural pigments to create biopaintings that result from the manipulation of organisms and their specific interactions. The author's biopaintings were obtained by controlling the growth of yeast cells on paper, ensuring the stability of the final results. These biopaintings resulted from the artist's observation and experimentation with evolving patterns of yeast biofilms. The oftenunexpected results are part of the creative process and suggest new artistic methodologies to be explored. An overview of the aesthetic manipulation of microorganisms by other artists is briefly presented. ©2011 ISAST.


Hoernig S.,New University of Lisbon
International Journal of Industrial Organization | Year: 2014

This paper presents a tractable model of network competition with many firms, elastic subscriber demand, off-net price discrimination, call externalities, and cost and market share asymmetries. We characterize stability in expectations and equilibrium under firm- and market-level network effects. The model is applied to simulate the effects of termination rates, market maturity, and retail pricing strategies. We show that predictions based on duopoly models can be misleading, in particular concerning the effects of termination rates. © 2013 Elsevier B.V.


Lavie-Cambot A.,CNRS Institute of Molecular Sciences | Lincheneau C.,CNRS Institute of Molecular Sciences | Lincheneau C.,Center for Synthesis and Chemical Biology | Cantuel M.,CNRS Institute of Molecular Sciences | And 3 more authors.
Chemical Society Reviews | Year: 2010

A strategy to manage energy, following light absorption, and modulate excited-state properties, including luminescence lifetimes of multicomponent photoactive systems, is presented. The intervening mechanism, which is illustrated through the use of bi-/multi-chromophoric molecules, relies on energy shuttling between different matched chromophores under kinetic and thermodynamic control. This tutorial review is destined to show supramolecular and materials chemists, spectroscopists and nanoscientists how to harness reversible electronic energy transfer in a predictable fashion in designer molecule-based systems. © 2010 The Royal Society of Chemistry.


Swift T.,New University of Lisbon
Semantic Web | Year: 2015

Knowledge representation systems based on the well-founded semantics can offer the degree of scalability required for semantic web applications and make use of expressive semantic features such as Hilog, frame-based reasoning, and defeasibility theories. Such features can be compiled into Prolog tabling engines that have good support for indexing and memory management. However, due both to the power of the semantic features and to the declarative style typical of knowledge representation rules, the resources needed for query evaluation can be unpredictable. In such a situation, users need to understand the overall structure of a computation and examine problematic portions of it. This problem, of profiling a computation, differs from debugging and justification which address why a given answer was or wasn't derived, and so profiling requires different techniques. In this paper we present a trace-based analysis technique called forest logging which has been used to profile large, heavily tabled computations. In forest logging, critical aspects of a tabled computation are logged; afterwards the log is loaded and analyzed. As implemented in XSB, forest logging slows down execution of practical programs by a constant factor that is often small; and logs containing tens or hundreds of millions of facts can be loaded and analyzed in minutes. © 2015-IOS Press and the authors. All rights reserved.


Pimentel M.A.F.,University of Lisbon | Pimentel M.A.F.,New University of Lisbon | Vilela P.,Hospital da Luz | Sousa I.,University of Lisbon | Figueiredo P.,University of Lisbon
Human Brain Mapping | Year: 2013

The new clinically available arterial spin labeling (ASL) perfusion imaging sequences present some advantages relatively to the commonly used blood oxygen level-dependent (BOLD) method for functional brain studies using magnetic resonance imaging (MRI). In particular, regional cerebral blood flow (CBF) changes are thought to be more directly related with neuronal activation. In this study, we aimed to investigate the accuracy of the functional localization of the hand motor area obtained by simultaneous CBF and BOLD contrasts provided by ASL functional MRI (fMRI) and compare it with a standard BOLD fMRI protocol. For this purpose, we measured the distance between the center of gravity of the activation clusters obtained with each contrast (CBF, BOLDASL, and Standard BOLD) and 11 positions defined on a well-established anatomical landmark of the hand motor area (the omega in the axial plane of the precentral gyrus). We found that CBF measurements were significantly closer to the anatomical landmark than the ones obtained using either simultaneous BOLDASL or standard BOLD contrasts. Moreover, we also observed reduced intersubject variability of the functional localization, as well as percent signal change, for CBF relative to both BOLD contrast measurements. In conclusion, our results add further evidence in support to the notion that CBF provides a more accurate localization of motor activation than BOLD contrast, indicating that ASL may be an appropriate technique for clinical fMRI studies. © 2011 Wiley Periodicals, Inc.


Huang J.,University of Newcastle | da Silva M.V.,University of Newcastle | da Silva M.V.,New University of Lisbon | Krabbenhoft K.,University of Newcastle | Krabbenhoft K.,University of Southern Denmark
Computers and Geotechnics | Year: 2013

A three-dimensional granular contact dynamics scheme is presented. The scheme is variational in structure, thus making it possible to solve the governing equations by means of mathematical programming methods. To facilitate the modeling of natural grains using spherical geometries, a rolling resistance model is developed. A number of static and dynamic benchmark examples are considered including the granular column collapse problem where the agreement between simulation and previously published experimental results is found to be very good. © 2012 Elsevier Ltd.


Coelho S.,New University of Lisbon
Seminars in Dialysis | Year: 2015

The definition of a good glycemic control in patients with diabetes mellitus on hemodialysis is far from settled. In the general population, hemoglobin A1c is highly correlated with the average glycemia of the last 8-12 weeks. However, in hemodialysis patients, the correlation of hbA1c with glycemia is weaker as it also reflects changes in hemoglobin characteristics and red blood cells half-life. As expected, studies show that the association between HbA1c and outcomes in these patients differ from the general population. Therefore, the value of HbA1c in the treatment of hemodialysis patients has been questioned. Guidelines are generally cautious in their recommendations about possible targets of HbA1c in this population. Indeed, the risk of not treating hyperglycemia should be weighed against the particularly high risk of precipitating hypoglycemia in dialysis patients. In this review, a critical analysis of the current role of HbA1c in the care of hemodialysis patients is presented. © 2015 Wiley Periodicals, Inc.


Hipolito I.,New University of Lisbon
Progress in Biophysics and Molecular Biology | Year: 2015

Kurt Gödel wrote (1964, p. 272), after he had read Husserl, that the notion of objectivity raises a question: "the question of the objective existence of the objects of mathematical intuition (which, incidentally, is an exact replica of the question of the objective existence of the outer world)". This "exact replica" brings to mind the close analogy Husserl saw between our intuition of essences in Wesensschau and of physical objects in perception. What is it like to experience a mathematical proving process? What is the ontological status of a mathematical proof? Can computer assisted provers output a proof? Taking a naturalized world account, I will assess the relationship between mathematics, the physical world and consciousness by introducing a significant conceptual distinction between proving and proof. I will propose that proving is a phenomenological conscious experience. This experience involves a combination of what Kurt Gödel called intuition, and what Husserl called intentionality. In contrast, proof is a function of that process - the mathematical phenomenon - that objectively self-presents a property in the world, and that results from a spatiotemporal unity being subject to the exact laws of nature. In this essay, I apply phenomenology to mathematical proving as a performance of consciousness, that is, a lived experience expressed and formalized in language, in which there is the possibility of formulating intersubjectively shareable meanings. © 2015 .


Lidon F.C.,New University of Lisbon | Ramalho J.C.,Institute Investigaao Cientifica Tropical
Journal of Photochemistry and Photobiology B: Biology | Year: 2011

The impact of UV-B radiation on photosynthetic related parameters was studied in Oryza sativa L. cv. Safari plants, after an UV-B irradiation performed 1 h per day for 7 days (between 8 and 14 days after germination) with a ten narrow-band (λ 311 nm) that resulted in a total biological effective UV-B (UVBBE) of 2.975 kJ m-2 day-1 and a total of 20.825 kJ m-2. Gas exchange measurements were severely affected, showing reductions higher than 80% in net photosynthesis (P n), stomatal conductance and photosynthetic capacity (A max), 1 day after the end of the 7-days UV-B treatment. Similarly, several fluorescence parameters (Fo, Fv/Fm, Fv′/Fm′, φe, qP and qE) and thylakoid electron transport (involving both photosystems) were also severely reduced. Concomitantly, a decline of xanthophylls, carotenes, Chl a, Chl (a + b) and Chl (a/b) values was accompanied by the increase of the lipoperoxidation level in chloroplast membranes, altogether reflecting a loss of protection against oxidative stress. Seven days after of the end of UV-B treatment, most fluorescence parameters recovered, but in Pn, Amax, thylakoid electron transport rates, Chl a and lipid classes, as well as the level of lipoperoxidation, the impacts were even stronger than immediately after the end of stress, denoting a clear loss of performance of photosynthetic structures. However, only a moderate impact on total lipids was observed, accompanied by some changes in the relative weight of the major chloroplast membrane lipid classes, with emphasis on the decrease of MGDG and the increase of phospholipids. That suggested an ability to de novo lipid synthesis allowing qualitative changes in the lipid matrix. Notably, the leaves developed after the end of UV-B irradiation showed a much lower impact, with significantly decreased values only in Pn and gs, rises in several fluorescence parameters, thylakoid electron transport, photosynthetic pigments (xanthophylls and chls) and DEPS, while lipid classes presented values close to control. The results showed a global impact of UV-B in the photosynthetic structures and performance in irradiated leaves, but revealed also a low impairment extent in the leaves entirely developed after the end of the irradiation, reflecting a remarkable recovery of the plant after the end of stress, what could constitute an advantage under occasional UV-B exposure events in this vital worldwide staple food crop. © 2011 Elsevier B.V. All rights reserved.


Moro A.J.,New University of Lisbon | Schmidt J.,Materials and Systems Research | Doussineau T.,University Claude Bernard Lyon 1 | Lapresta-Fernandez A.,University of Seville | And 2 more authors.
Chemical Communications | Year: 2011

The design of two-dyed fluorescent silica nanoparticles for ATP detection is presented. The indicator dye possesses a dipicolyl-amine (DPA) unit complexed with Zn(ii) as a receptor function for ATP while a rhodamine derivative is used as the reference dye. The nanoparticles were fully characterized regarding analytical performance, morphology and cytocompatibility. © 2011 The Royal Society of Chemistry.


Magalhaes J.,New University of Lisbon | Ruger S.,Open University Milton Keynes
ACM Transactions on Information Systems | Year: 2010

This article is set in the context of searching text and image repositories by keyword. We develop a unified probabilistic framework for text, image, and combined text and image retrieval that is based on the detection of keywords (concepts) using automated image annotation technology. Our framework is deeply rooted in information theory and lends itself to use with other media types. We estimate a statistical model in a multimodal feature space for each possible query keyword. The key element of our framework is to identify feature space transformations that make them comparable in complexity and density. We select the optimal multimodal feature space with a minimum description length criterion from a set of candidate feature spaces that are computed with the average-mutual-information criterion for the text part and hierarchical expectation maximization for the visual part of the data. We evaluate our approach in three retrieval experiments (only text retrieval, only image retrieval, and text combined with image retrieval), verify the framework's low computational complexity, and compare with existing state-of-the-art ad-hoc models. © 2010 ACM.


Cywinski P.J.,University of Potsdam | Moro A.J.,New University of Lisbon | Lohmannsroben H.-G.,University of Potsdam
Biosensors and Bioelectronics | Year: 2014

Novel luminescent ratiometric nanosensors (QD-NAPTHs) were prepared based on cadmium telluride (CdTe655) quantum dots as luminescent nanoscaffolds with naphthyridine dyes as fluorescent receptors. This biosensing bifluorophoric nanosystem has been designed to achieve detection of guanosine 3',5'-cyclic monophosphate (cyclic GMP) in buffered media. Cyclic GMP is a secondary messenger that is an important factor for detecting cancer, diabetes and, cardiovascular diseases. Due to low concentration levels, even in pathological conditions, sensitive cGMP detection remains a challenge for modern biomedical diagnostics. Here, QD-NAPTH nanosensors were tested in the presence of a target nucleotide and with various structural cGMP analogues. Steady-state fluorescence spectroscopy was used to monitor a change in the nucleotide concentration. A 5-fold increase in naphthyridine fluorescence with a simultaneous decrease in QD luminescence was observed after adding 50. μM of cGMP. Using this novel nanosystem with ratiometric detection, it was possible to recognize cGMP with limit of detection (3. σ) equal to 70. ng/ml. Moreover, the enhancement in fluorescence upon interaction with the target nucleotide constitutes a favourable approach towards the detection of cGMP in buffered media. These bifluorophoric nanosensors have a potential for application in fluorescence microscopy imaging and in-vitro assays. © 2013 Elsevier B.V.


Figueiredo J.,University of Evora | Martins J.,New University of Lisbon
Energy Conversion and Management | Year: 2010

Intelligent buildings, historically and technologically, refers to the integration of four distinctive systems: Building Automation Systems (BAS), Telecommunication Systems, Office Automation Systems and Computer Building Management Systems. The increasing sophisticated BAS has become the "heart and soul" of modern intelligent buildings. Integrating energy supply and demand elements - often known as Demand-Side Management (DSM) - has became an important energy efficiency policy concept. Nowadays, European countries have diversified their power supplies, reducing the dependence on OPEC, and developing a broader mix of energy sources maximizing the use of renewable energy domestic sources. In this way it makes sense to include a fifth system into the intelligent building group: Energy Production System Management (EPSM). This paper presents a Building Automation System where the Demand-Side Management is fully integrated with the building's Energy Production System, which incorporates a complete set of renewable energy production and storage systems. © 2009 Elsevier Ltd. All rights reserved.


da Costa Lopes A.M.,National Laboratory of Energy and Geology | Joao K.G.,National Laboratory of Energy and Geology | Rubik D.F.,National Laboratory of Energy and Geology | Rubik D.F.,Regional University of Blumenau | And 4 more authors.
Bioresource Technology | Year: 2013

This work is devoted to study pre-treatment methodologies of wheat straw with 1-ethyl-3-methylimidazolium acetate ([emim][CH3COO]) and subsequent fractionation to cellulose, hemicellulose and lignin. The method developed and described here allows the separation into high purity carbohydrate and lignin fractions and permits an efficient IL recovery. A versatility of the established method was confirmed by the IL reuse.The fractionation of completely dissolved biomass led to cellulose-rich and hemicellulose-rich fractions. A high purity lignin was also achieved.To verify the potential further applicability of the obtained carbohydrate-rich fractions, and to evaluate the pre-treatment efficiency, the cellulose fraction resulting from the treatment with [emim][CH3COO] was subjected to enzymatic hydrolysis. Results showed a very high digestibility of the cellulose samples and confirmed a high glucose yield for the optimized pre-treatment methodology. © 2013 Elsevier Ltd.


Swift T.,New University of Lisbon
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2011

The use of design patterns is common in many areas of software engineering and programming. While they are informal, patterns provide a repository of solutions to common problems, as well as a survey of the features of a given language or software system. This paper uses design patterns to survey features and applications of Tabled Logic Programming (TLP). Patterns for commonly available features are presented, such as those of various recursion types that arise when tabling is used with definite programs, of automatic tabling and of tabling with DCGs. In addition, various patterns capture well-developed uses of tabled negation for non-monotonic reasoning. A final set of patterns describes the approaches of answer subsumption and tabled constraints, features that have fewer applications to date due to the fact that robust implementations of them have only recently become available. © 2011 Springer-Verlag Berlin Heidelberg.


Goncalves R.,New University of Lisbon | Ritto-Correa M.,University of Lisbon | Camotim D.,University of Lisbon
Computational Mechanics | Year: 2011

In this paper, a large displacement and finite rotation thin-walled beam element previously developed by the authors, which accounts for cross-section deformation, is extended by including finite relative rotations of the beam walls in the in-plane kinematic description of the cross-sections. The inclusion of these relative rotations is motivated by the fact that it enables a simple and meaningful representation of the cross-section in-plane distortion and allows for a co-rotational description of the wall "local-plate" behavior, which leads to a computationally efficient numerical implementation. The present extension preserves all features of the original formulation, namely the geometrically exact description of the beam mid-surface and the allowance for arbitrary cross-section deformation modes complying with Kirchhoff's assumption. The efficiency of the resulting beam finite element is demonstrated by means of numerical examples, which include comparisons with solutions obtained by means of the previous beam finite element and standard shell finite elements. © 2011 Springer-Verlag.


Gomes L.,New University of Lisbon | Gomes L.,Institute Desenvolvimento Of Novas Tecnologias | Lourenco J.,Empresa de Investigacao e Desenvolvimento de Electronica EID
IEEE Transactions on Industrial Electronics | Year: 2010

This paper describes a tool framework allowing the rapid prototyping of an animated synoptic application associated with an embedded system controller. The motto for developing this tool framework is to be able to automatically generate controllers with associated graphical user interface (GUI) without writing a line of execution code; instead, the tool framework will provide specific aids allowing the designer to define the controller behavior and associated GUI (including static parts and intended dynamics). The behavior of the controller is described through a low-level Petri-net model, and the tool framework supports the definition of characteristics for the intended GUI and the association of the characteristics of the Petri-net behavioral model with specific characteristics of the GUI through a set of dedicated rules. Two main tools are described. The first one, named as Animator, allows an interactive definition of the graphical characteristics of the synoptic and automatic code generation. The second one, named as Synoptic, is responsible for the embedded control-execution part, integrating real-time updating of the GUI. The application of the tool framework to a simple automation system, namely, to the controller of a manufacturing system composed of a four-cell first-infirst-out system, is presented. © 2006 IEEE.


Povoa P.,Polyvalent Intensive Care Unit | Povoa P.,New University of Lisbon | Salluh J.I.F.,DOr Institute for Research and Education | Salluh J.I.F.,Instituto Nacional Of Cancer
Annals of Intensive Care | Year: 2012

Biomarkers of infection, namely C-reactive protein and procalcitonin (PCT), are potentially useful in the diagnosis of infection as well as in the assessment of its response to antibiotic therapy. C-reactive protein variations overtime appears to have a good performance for the diagnosis of infection. Procalcitonin shows a better correlation with clinical severity. In addition, to overcome the worldwide problem of antibiotic overuse as well as misuse, biomarker guidance of antibiotic stewardship represents a promising new approach. In several randomized, controlled trials, including adult critically ill patients, PCT guidance was repeatedly associated with a decrease in the duration of antibiotic therapy. However, these trials present several limitations, namely high rate of patients' exclusion, high rate of algorithm overruling, long duration of antibiotic therapy in the control group, disregard the effect of renal failure on PCT level, and above all a possible higher mortality and higher late organ failure in the PCT arm. In addition, some infections (e.g., endocarditis) as well as frequent nosocomial bacteria (e.g., Pseudomonas aeruginosa) are not suitable to be assessed by PCT algorithms. Therefore, the true value of PCT-guided algorithm of antibiotic stewardship in assisting the clinical decision-making process at the bedside remains uncertain. Future studies should take into account the issues identified in the present review. © 2012 Póvoa and Salluh; licensee Springer.


Ortigueira M.D.,New University of Lisbon | Rivero M.,University of La Laguna | Trujillo J.J.,University of La Laguna
International Journal of Bifurcation and Chaos | Year: 2012

The generalized incremental ratio fractional derivative is revised and its main properties deduced. It is shown that in the case of analytic functions, it enjoys some interesting properties like: linearity and causality and has a semi-group structure. Some simple examples are presented. The enlargement of the set of functions for which the group properties of the fractional derivative are valid is done. With this, it is shown that some well-known results are valid in a more general set-up. Some examples are presented. © 2012 World Scientific Publishing Company.


Cruz C.,University of Beira Interior | Cabrita E.J.,New University of Lisbon | Queiroz J.A.,University of Beira Interior
Journal of Chromatography A | Year: 2011

The epitope mapping of nucleotides bound to three chromatography supports is accomplished using saturation transfer difference (STD)-NMR spectroscopy. This experiment involves subtracting a spectrum in which the support was selectively saturated from one recorded without support saturation. In the difference spectrum only the signals of the ligands that bind to the support and received saturation transfer remain. The nucleotide protons in closer contact with the support have more intense signals due to a more efficient transfer of saturation. We investigate the effects on the binding to the nucleotides by the introduction of a spacer arm between l-histidine and Sepharose. Our NMR experiments evidence a clear contribution of the spacer to the interaction with all the nucleotides, increasing the mobility of the amino acid and giving different STD responses. This enhanced mobility originates the reinforcement of the interactions with the sugar moiety and phosphate group of 5'-CMP and 5'-TMP or the base of 5'-GMP and 5'-UMP. Hence, with this study we show that by using STD NMR technique on chromatographic systems it is possible to provide a fast, robust and efficient way of screening the atoms involved in the binding to the supports. © 2011 Elsevier B.V.


Pereira F.,New University of Lisbon
Carbohydrate Research | Year: 2011

A machine learning approach was explored for the prediction of the anomeric configuration, residues, and type of linkages of disaccharides using 13C NMR chemical shifts. For this study, 154 pyranosyl disaccharides were used that are dimers of the α or β anomers of d-glucose, d-galactose or d-mannose residues bonded through α or β glycosidic linkages of types 1→2, 1→3, 1→4, or 1→6, as well as methoxylated disaccharides. The 13C NMR chemical shifts of the training set were calculated using the casper (Computer Assisted SPectrum Evaluation of Regular polysaccharides) program, and chemical shifts of the test set were experimental values obtained from the literature. Experiments were performed for (1) classification of the anomeric configuration, (2) classification of the type of linkage, and (3) classification of the residues. Classification trees could correctly classify 67%, 74%, and 38% of the test set for the three tasks, respectively, on the basis of unassigned chemical shifts. The results for the same experiments using Random Forests were 93%, 90%, and 68%, respectively. © 2011 Published by Elsevier Ltd.


Carmo M.,University of Lisbon | Moreira F.,University of Lisbon | Casimiro P.,New University of Lisbon | Vaz P.,University of Lisbon
Landscape and Urban Planning | Year: 2011

Understanding the spatial patterns of wildfire ignition and spread has important implications for landscape planning for reducing fire hazard. In this paper we characterise the patterns of wildfire occurrence in 3 regions of northern Portugal, using selection ratio functions to evaluate the fire proneness of different land cover and topographic categories. For attaining this objective we characterised 1382 wildfires larger than 5. ha, which occurred in the years 1990-1991, according to land cover (10 categories), slope (5 categories) and aspect (5 categories) within which they occurred. For each fire, the use of the different land cover and topographic categories was compared with availability in a surrounding buffer. For land cover, fire proneness was much higher in shrublands, whereas agricultural areas and agro-forestry systems where less likely to burn. In terms of slope, steep slopes were more prone to fire. Differences in land cover in the different slope categories contributed to this result, although there was an overall slope effect on the fire proneness of all land cover types. In terms of aspect, only flat areas were less fire prone. Finally, there were regional variations in land cover susceptibility to fire, but these did not occur for slope or aspect. In terms of landscape planning these results suggest that the more effective fuel breaks should be implemented in areas with agricultural crops in flat slopes. © 2011 Elsevier B.V.


Goncalves R.,New University of Lisbon
Computers and Structures | Year: 2012

In this paper, a new geometrically exact beam formulation is presented, aiming at calculating buckling (bifurcation) loads of Euler-Bernoulli/Vlasov thin-walled beams with deformable cross-section. The resulting finite element is particularly efficient for problems involving coupling between lateral-torsional buckling and cross-section distortion/local-plate buckling. The kinematic description of the beam is geometrically exact and employs rotation tensors associated with both cross-section rotation and the relative rotations of the cross-section walls in the cross-section plane. Moreover, arbitrary deformation modes, complying with Kirchhoff's assumption, are also included, which makes it possible to capture local/distortional/global buckling phenomena. Load height effects associated with cross-section rotation/deformation are also included. The examples presented throughout the paper show that the proposed beam finite element leads to accurate solutions with a relatively small number of degrees-of-freedom (deformation modes and finite elements). © 2012 Elsevier Ltd. All rights reserved.


Da Costa Lopes A.M.,National Laboratory of Energy and Geology | Joao K.G.,National Laboratory of Energy and Geology | Bogel-LUkasik E.,New University of Lisbon | Roseiro L.B.,National Laboratory of Energy and Geology | Bogel-LUkasik R.,National Laboratory of Energy and Geology
Journal of Agricultural and Food Chemistry | Year: 2013

Pretreatment of lignocellulosic biomass with ionic liquids (ILs) is a promising and challenging process for an alternative method of biomass processing. The present work emphasizes the examination of wheat straw pretreatment using ILs, namely, 1-butyl-3-methylimidazolium hydrogensulfate ([bmim][HSO4]), 1-butyl-3-methylimidazolium thiocyanate ([bmim][SCN]), and 1-butyl-3-methylimidazolium dicyanamide ([bmim][N(CN) 2]). Only [bmim][HSO4] was found to achieve a macroscopic complete dissolution of wheat straw during pretreatment. The fractionation process demonstrated to be dependent on the IL used. Using [bmim][SCN], a high-purity lignin-rich material was obtained. In contrast, [bmim][N(CN) 2] was a good solvent to produce high-purity carbohydrate-rich fractions. When [bmim][HSO4] was used, a different behavior was observed, exhibiting similarities to an acid hydrolysis pretreatment, and no hemicellulose-rich material was recovered during fractionation. A capillary electrophoresis (CE) technique allowed for a better understanding of this phenomenon. Hydrolysis of carbohydrates was confirmed, although an extended degradation of monosaccharides to furfural and hydroxymethylfurfural (HMF) was observed. © 2013 American Chemical Society.


de Almeida M.A.P.,New University of Lisbon
Historia, Ciencias, Saude - Manguinhos | Year: 2011

The article examines science and technology communication aimed at a non-specialized audience, using the general press as the main source in this endeavor to capture an image of the popularization of science in Portugal. Based on the fact that the nineteenth-century press was overtly concerned with garnering an audience and spreading knowledge, the study uses news, articles, and advertisements about the 1853-1856 cholera epidemic to assess the era's scientific knowledge (especially about prevention and treatment) and how this information was conveyed to society and used by it.


Rodriguez L.,University of Barcelona | Ferrer M.,University of Barcelona | Crehuet R.,CSIC - Institute of Advanced Chemistry of Catalonia | Anglada J.,CSIC - Institute of Advanced Chemistry of Catalonia | Lima J.C.,New University of Lisbon
Inorganic Chemistry | Year: 2012

The systematic analysis of the luminescence of a series of alkynyl gold derivatives with general formulas [(diphos)(AuC≡Cpy)2] (diphosphane =2,2′-bis(diphenylphosphanyl)propane or dppip (1), bis(diphenylphosphanyl)acetylene or dppa (2), 1,2-bis(diphenylphosphanyl)ethane or dppe (3) and 1,4-bis(diphenylphosphanyl)butane or dppb, (4), has shown a straightforward correlation between the Au(I)⋯Au(I) distance and the emission quantum yields and decaytimes. The analysis of the decaytimes, quantum yields and thus, the corresponding calculated rate constants demonstrated the existence of a correlation between Au(I) ⋯Au(I) distance and the radiative rate constant for the deactivation of the emissive triplet states. It was concluded that the increased emission of these compounds results from the increase in spin-orbit coupling that favors the spin forbidden transition to the singlet ground state. © 2012 American Chemical Society.


Goncalves R.,New University of Lisbon | Camotim D.,University of Lisbon
Thin-Walled Structures | Year: 2014

This paper addresses the free vibration behaviour of single-cell thin-walled tubes with regular convex polygonal cross-section (RCPS) and provides an extensive analysis of the resulting natural frequencies and associated vibration mode shapes. A semi-analytical approach is adopted, which is based on the generalised beam theory (GBT) specialisation for RCPS recently proposed by Gonçalves and Camotim (2013) [1] and subsequently employed to obtain insightful conclusions concerning the buckling behaviour of RCPS tubes (Gonçalves and Camotim (2013) [2,3]). This approach makes it possible to obtain closed-form analytical solutions and also acquire in-depth knowledge concerning the mechanics of the vibration problem, through the well-known GBT modal decomposition features. Attention is paid to local (plate-like), extensional, torsional and distortional vibration modes, as well as their interaction. © 2014 Elsevier Ltd.


Royo B.,New University of Lisbon | Peris E.,Jaume I University
European Journal of Inorganic Chemistry | Year: 2012

This microreview focuses on the preparation of metal complexes with N-heterocyclic carbene ligands linked to cyclopentadienyl (and related indenyl and fluorenyl) rings. Since the description of the first Ti and V complexes in 2006, the field has grown to afford a large number of new complexes, in which the metals range from early to late transition metals. The ligands that are now available not only include a wide set of cyclopentadienyl-, indenyl- and fluorenyl-NHCs with a variety of tethers, but may even present chirality. Several catalytic applications of the new complexes are described, including borrowing hydrogen processes (transfer hydrogenation, β-alkylation of secondary alcohols, alkylation of amines with primary alcohols), hydrosilylation of aldehydes, epoxidation and hydroformylation of olefins, among others. This microreview focuses on the preparation of new N-heterocyclic carbenes linked to cyclopentadienyl-, indenyl-, and fluorenyl rings and their coordination to early and late transition metals. Several catalytic applications of the new metal complexes are described. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Viana-Baptista M.,New University of Lisbon | Viana-Baptista M.,Centro Hospitalar Lisbon Ocidental
Journal of Neurology | Year: 2012

Fabry disease (FD) is a rare inherited disorder of the metabolism, associated with renal, cardiac, and cerebrovascular complications. Ischemic and hemorrhagic stroke in FD present with a similar proportion to that observed in the general population, but usually at an early age. Ischemic stroke may result from cardiac embolism, large and small vessel disease, while hemorrhagic stroke is usually attributed to hypertension. Deposition of glycosphingolipids in endothelial cells results in a specific FD vasculopathy that contributes to the different vascular phenotypes. Neuroimaging features of cerebrovascular involvement in FD include white matter lesions, dolichoectasia, and the "pulvinar sign", a T1 MRI hyperintensity of the posterior thalamus. The role of enzymatic replacement therapy in the prevention of stroke remains to be established, but its utilization should be considered in FD stroke patients, for prevention of renal and cardiac complications, together with general prevention measures. Enzymatic replacement therapy increased our awareness of FD, underlining the importance of incomplete phenotypes in specific settings such as stroke. An overview of studies on the prevalence of FD in stroke patients is presented. Available data suggest that prevalence of FD is similar to some of the rare causes of stroke usually considered, and that classic features of the disease may be absent or more subtle. Moreover, FD should be considered in both cryptogenic and all-cause stroke. The role of FD in stroke on a multifactorial basis and the identification of a putative "stroke variant" are questions that need to be further elucidated in future studies. © 2011 Springer-Verlag.


Lima J.C.,New University of Lisbon | Rodriguez L.,University of Barcelona
Anti-Cancer Agents in Medicinal Chemistry | Year: 2011

Gold complexes have been explored as metallodrugs with great potential applications as antitumoral agents. In particular, gold-phosphine derivatives seemed quite promising since the use of the antiarthritic auranofin drug (thiolate-Au-PEt 3 complex) presented also biological activity against different cancer cells. So, different auranofin analogues have been explored within this context and for this reason, the main number of phosphine-gold complexes developed with this goal contain thiolate ligands. Other complexes have been also studied such as tetrahedral bis(phosphine)gold(I) and phosphine-gold-halides. Very recently, phosphine-gold-alkynyl complexes have also shown very interesting biological activities although few reports are published related to them. Their mechanism of action seems to be clearly different that the used by platinum drugs (DNA intercalating processes) and recent studies point to be related to the inhibition of Trx reductase. Cellular uptake and biodistribution studies are well reported in the original works but the use of luminescence techniques is relatively less explored. For this, the use of these techniques is also specifically reported in this review. © 2011 Bentham Science Publishers.


Fernandes A.M.,University of Aveiro | Rocha M.A.A.,University of Aveiro | Freire M.G.,University of Porto | Marrucho I.M.,New University of Lisbon | And 2 more authors.
Journal of Physical Chemistry B | Year: 2011

Electrospray ionization mass spectrometry with variable collision induced dissociation of the isolated [(cation)2anion]+ and/or [(anion)2cation]- ions of imidazolium-, pyridinium-, pyrrolidinium-, and piperidinium-based ionic liquids (ILs) combined with a large set of anions, such as chloride, tetrafluoroborate, hexafluorophosphate, trifluoromethanesulfonate, and bis[(trifluoromethyl)sulfonyl]imide, was used to carry out a systematic and comprehensive study on the ionic liquids relative interaction energies. The results are interpreted in terms of main influences derived from the structural characteristics of both anion and cation. On the basis of quantum chemical calculations, the effect of the anion upon the dissociation energies of the ionic liquid pair, and isolated [(cation) 2anion]+ and/or [(anion)2cation]- aggregates, were estimated and are in good agreement with the experimental data. Both experimental and computational results indicate an energetic differentiation between the cation and the anion to the ionic pair. Moreover, it was found that the quantum chemical calculations can describe the trend obtained for the electrostatic cation-anion attraction potential. The impact of the cation-anion interaction strengths in the surface tension of ionic liquids is further discussed. The surface tensions dependence on the cation alkyl chain length, and on the anion nature, follows an analogous pattern to that of the relative cation-anion interaction energies determined by mass spectrometry. © 2011 American Chemical Society.


Reboredo F.,New University of Lisbon
International Forestry Review | Year: 2013

Illegal logging is a major global problem causing damage to forests, indigenous people and to the economies of the main wood producer countries. Europe as a whole is an important producer and consumer partner and it is likely that the circulation of illegal wood also takes place within EU borders. This Review tries to identify the main EU wood suppliers and discuss the discrepancies in official and non-official statistical data between wood production and consumption, which difficult the accurate validation of the suspicious flows. The importance of Voluntary Partnership Agreements within the EU and main producer countries is emphasized. Finally, and despite the measures to tackle illegal logging, all initiatives must be extensive and uniform throughout the EU and focused in the use of certified timber.


Raposo C.C.B.G.,New University of Lisbon
Synlett | Year: 2013

(A) Alkylation of Diiodomethane Bull and Charette reported an improved procedure to obtain functionalized gem-diiodoalkanes with acceptable functional group tolerance towards olefins, acetals, ethers, carbamates, and hindered esters. (B) β-Elimination of 2-Halogen-3-hydroxyesters and Synthesis of (Z)-Vinyl Halides (E)-α,β-Unsaturated esters were synthesized from 2-halo-3-hydroxyesters in good to excellent yields using a mixture of metallic samarium and diiodomethane. (Z)-Vinyl halides can be obtained with high diastereoselectivities and yields from O-acetylated 1,1-diiodo alcohols, metallic samarium, and diiodomethane in THF at room temperature. (C) Synthesis of 2,3-Dideuterioesters The 1,4-reduction of α,β-unsaturated esters with D2O in the presence of metallic samarium and diiodomethane afforded the corresponding 2,3-dideuterioesters in good to excellent yields. (D) Transformation of Carbonyl Compounds into Epoxides Epoxides are important because they can be opened by a variety of nucleophiles to afford 1,2-difunctionalized systems. Concellón et al. reported a general, easy, and simple transformation of aldehydes and ketones into epoxides with excellent yields using diiodomethane and methyllithium at 0°C. (E) Synthesis of (E)-α-Hydroxy-β,γ-unsaturated Amides Concellón and co-workers11 reported an easy and simple procedure to prepare (E)-α-hydroxy-β,γ-unsaturated amides using metallic samarium and diiodomethane with high regio- and diastereoselectivity. (F) Cyclopropanation Cyclopropanation of alkenes can be carried out by a mixture of metallic samarium and diiodomethane.11 Cyclopropanation of terminal alkynes under the action of diiodomethane and triethylaluminum proceeded stereoselectively. (G) Iodomethylation of Amino Aldehydes The halomethylation of carbonyl compounds is difficult to achieve due to the instability of halomethyllithium compounds. As an alternative, Bernad et al. reported a smoothly proceeding reaction using metallic samarium and diiodomethane. (H) Double Carbonylation of Diiodomethane Double carbonylation of diiodomethane in triethylorthoformate in the presence of catalytic amounts of rhodium complex gave diethylmalonate in good yield. (I) Sigmatropic Rearrangement Li and co-workers described an efficient method for the synthesis of β-diketones from aromatic α-bromo ketones in the presence of diiodomethane and diethylzinc. Aliphatic α-bromomethyl ketones gave 2,4-disubstituted furans or cyclopropanols in moderate yield. (J) Diazotization for the Synthesis of Aryl Iodides The reactions of aryl amines in the presence of isoamyl nitrite and diiodomethane formed aryl iodides cleanly and in good yield. (K) Coupling Molecules with a CH2 Linkage In the synthesis of ditopic ligands, bispyrazolylpyridine molecules can be coupled with CH2 linkages using sodium hydride and diiodomethane in dichloromethane with moderate yields, as reported by Zadykowicz and Potvin.


Castro A.,University of Huelva | Aghazadeh M.,Payame Noor University | Badrzadeh Z.,Payame Noor University | Chichorro M.,New University of Lisbon
Lithos | Year: 2013

A potassic magmatic association in the Zagros hinterland of the Tethyan orogen in Iran is identified and characterized for relevant geochronologic and petrologic features. New data, including a combination of field relations, U-Pb zircon geochronology and rock geochemistry, come from seven plutons (Khankandi, Shaivar-Dagh, Yuseflu, Mizan, Saheb-Divan, Roudbar and Abhar) that form the Arasbaran-Taroum batholith (ATB), which forms part of the Alborz magmatic belt (AMB) of NW Iran. Zircon SHRIMP ages range from 38.32±0.17Ma, 38.94±0.42Ma and 37.78±0.28Ma for magma pulses of the Abhar pluton, at the East of the batholith, to 24.51±0.27Ma and 23.55±0.47Ma for pulses of the Mizan pluton at the West. Considering these ages and the previously published ones together, emplacement of the batholith took place during Late Eocene and Oligocene, from 38 to 23Ma, with an age progression from SE to NW at a rate of 2cm/year. The whole batholith is characterized by potassic rocks with K2O>2wt.% in gabbros and diorites (SiO2<50wt.%). Higher contents of K2O, of up to >6wt.%, are normally found in rocks with intermediate silica contents of about 60wt.% SiO2. These intermediate silica rocks are truly monzonites and are the most abundant in each pluton. With regard to trace elements, the monzonitic rocks of the ATB show some of the typical signatures of arc magmatism (depletion in Nb and Ti). Most samples contain moderate contents of Sr (500-800ppm), close to similar potassic magmas forming Cenozoic complexes in Central Iran. The relatively moderate Sr/Y and La/Yb ratios suggest that ATB magmas retain some adakitic signatures from the source region. Geochemical modeling is performed by using melt compositions and phase relations calculated with MELTS software, combined with experimental data and trace element signatures. We conclude that monzonitic and shoshonitic magmas of some plutons of the ATB (Shaivar-Dagh, Kahnkandi and Yuseflu) have an adakitic signature inherited from early melts that metasomatized the peridotite mantle. Decompression melting at a relatively low pressure of a metasomatized mantle source is the most plausible explanation for the generation of potassic magmas of the ATB. The lack of adakitic signature in three plutons supports the hypothesis that trace-element features are related to processes in the source. The tectonic implications are straightforward: First, subduction is needed to cook a metasomatized mantle source by fluxing of calc-alkaline melts (adakitic or not) from the subduction zone. Second, lithosphere extension is needed to carry metasomatized mantle to melt and to generate the potassic magmatism that formed the Arasbaran-Taroum batholith, as well as other Cenozoic potassic magmas of the Alborz magmatic belt in NW Iran. © 2013 Elsevier B.V.


Ortigueira M.D.,New University of Lisbon
IEEE Signal Processing Magazine | Year: 2014

The recursive solution of the autocorrelation normal equations was recovered in a recent article by Baran and Oppenheim [1]. The algorithm they obtained is slightly different from the one currently described in the literature [9]. However, they did not reallize the importance of the difference. I discovered it almost 30 years ago [4], [6] and used it to propose a modified Burg method as alternative to the well-known Burg method [2] that emerged directly from the classic Durbin-Levinson algorithm. In fact, the solution of the normal equations Baran, Oppenheim, and I obtained leads to predictors that are different from those acquired with the classic Durbin-Levinson algorithm. We will see the difference by looking into the recursions verified by the corresponding prediction error filters. © 1991-2012 IEEE.


Zhou Y.,Nanyang Environment and Water Research Institute | Oehmen A.,New University of Lisbon | Vadivelu V.,Universiti Sains Malaysia | Ng W.J.,Nanyang Environment and Water Research Institute
Water Research | Year: 2011

Nitrite is known to accumulate in wastewater treatment plants (WWTPs) under certain environmental conditions. The protonated form of nitrite, free nitrous acid (FNA), has been found to cause severe inhibition to numerous bioprocesses at WWTPs. However, this inhibitory effect of FNA may possibly be gainfully exploited, such as repressing nitrite oxidizing bacteria (NOB) growth to achieve N removal via the nitrite shortcut. However, the inhibition threshold of FNA to repress NOB (∼0.02mg HNO 2-N/L) may also inhibit other bioprocesses. This paper reviews the inhibitory effects of FNA on nitrifiers, denitrifiers, anammox bacteria, phosphorus accumulating organisms (PAO), methanogens, and other microorganisms in populations used in WWTPs. The possible inhibition mechanisms of FNA on microorganisms are discussed and compared. It is concluded that a single inhibition mechanism is not sufficient to explain the negative impacts of FNA on microbial metabolisms and that multiple inhibitory effects can be generated from FNA. The review would suggest further research is necessary before the FNA inhibition mechanisms can be more effectively used to optimize WWTP bioprocesses. Perspectives on research directions, how the outcomes may be used to manipulate bioprocesses and the overall implications of FNA on WWTPs are also discussed. © 2011 Elsevier Ltd.


Moreira E.E.,New University of Lisbon | Moreira E.E.,University of Lisbon
Physics and Chemistry of the Earth | Year: 2015

A log-linear modelling for 3-dimensional contingency tables was used with categorical time series of SPI drought class transitions for prediction of monthly drought severity. Standardized Precipitation Index (SPI) time series in 12- and 6-month time scales were computed for 10 precipitation time series relative to GPCC datasets with 2.5° spatial resolution located over Portugal and with 112 years length (1902-2014). The aim was modelling two-month step class transitions for the wet and dry seasons of the year and then obtain probability ratios - Odds - as well as their respective confidence intervals to estimate how probable a transition is compared to another. The prediction results produced by the modelling applied to wet and dry season separately, for the 6- and the 12-month SPI time scale, were compared with the results produced by the same modelling without the split, using skill scores computed for the entire time series length. Results point to good prediction performances ranging from 70 to 80% in the percentage of corrects (PC) and 50-70% in the Heidke skill score (HSS), with the highest scores obtained when the modelling is applied to the SPI12. The adding up of the wet and dry seasons introduced in the modelling brought improvements in the predictions, of about 0.9-4% in the PC and 1.3-6.8% in the HSS, being the highest improvements obtained in the SPI6 application. © 2015 Acta Materialia Inc.


Tsonev T.,Bulgarian Academy of Science | Lidon F.J.C.,New University of Lisbon
Emirates Journal of Food and Agriculture | Year: 2012

Owing to continuous development of knowledge at a biophysics, biochemistry, molecular biology and genetics levels, essential progresses to understand the mechanisms underlying the threshold of Zn toxicity has been achieved. Following this background, Zn uptake and translocation and its functions in plants are described, being its toxic effect on growth, photosynthetic activity and oxidative stress discussed. The extent of plant injury by elevated Zn concentrations is also assessed, considering its specific and strong dependence on the environmental conditions and availability of other heavy metals.


Fernandes H.L.,Northwestern University | Fernandes H.L.,Instituto Gulbenkian Of Ciencia | Fernandes H.L.,New University of Lisbon | Stevenson I.H.,University of California at Berkeley | And 4 more authors.
Cerebral Cortex | Year: 2014

The frontal eye field (FEF) plays a central role in saccade selection and execution. Using artificial stimuli, many studies have shown that the activity of neurons in the FEF is affected by both visually salient stimuli in a neuron's receptive field and upcoming saccades in a certain direction. However, the extent to which visual and motor information is represented in the FEF in the context of the cluttered natural scenes we encounter during everyday life has not been explored. Here, we model the activities of neurons in the FEF, recorded while monkeys were searching natural scenes, using both visual and saccade information. We compare the contribution of bottom-up visual saliency (based on low-level features such as brightness, orientation, and color) and saccade direction. We find that, while saliency is correlated with the activities of some neurons, this relationship is ultimately driven by activities related to movement. Although bottom-up visual saliency contributes to the choice of saccade targets, it does not appear that FEF neurons actively encode the kind of saliency posited by popular saliency map theories. Instead, our results emphasize the FEF's role in the stages of saccade planning directly related to movement generation. © The Author 2013. Published by Oxford University Press.


Kale S.R.,Institute of Chemical Technology | Kahandal S.S.,Institute of Chemical Technology | Gawande M.B.,New University of Lisbon | Jayaram R.V.,Institute of Chemical Technology
RSC Advances | Year: 2013

A simple and novel γ-Fe2O3 supported on hydroxyapatite (HAP) heterogeneous catalytic system is described that is useful in the synthesis of disubstituted 1,2,3-triazoles from terminal alkynes and in situ generated organic azide in aqueous media; this green methodology emerges as this new catalyst for the one-pot synthesis of 1,2,3-triazoles can be used in water without the addition of any reagent/base. The catalyst can be successfully recycled five times without significant loss of activity. It is important to note that 100% regioselectivity was observed for the cycloaddition reaction. This journal is © 2013 The Royal Society of Chemistry.


Pessoa M.F.,New University of Lisbon
Emirates Journal of Food and Agriculture | Year: 2012

UV radiation became an important issue since the awareness of the ozone hole in Antarctida and its relationship between the human activity, the depletion of the protecting layer, and the effects of ultraviolet radiation in the biological relevant wavebands on algae and on organisms in general. All aquatic organisms are depended on algae and aquatic plants (submerged or near shallow line) for food, shelter, also as oxygen supplement and CO2 sequestration by photosynthetic procedure. So, a disturbance in this trophic layer creates a global unbalancing. Harmful effects of UV, especially UV-B were intensibly studied under laboratory and field studies, and reported in scientific reports from a large team of scientists. UV- induced repair mechanisms allowing the survival of certain species under UV irradiation is also largely documented in algae species, and in phytoplankton of the entire aquatic systems (freshwater, marine and brackiswater). This study provides an overview of the available literature on the ultraviolet-B (UV-B - λ=280-315 nm) and UV-A radiation (λ=315-400 nm) concerning the strategies of protection developed by aquatic photoauthotrophs (micro and macroalgae, and aquatic macrophytes, like seagrasses and liverworts) to fit under these wavebands of radiation. It includes studies on prokariotic cyanobacteria, haptophytes, diatoms, dinoflagellates, red algae, brown algae and chlorophytes from freshwater (ponds, lakes) to marine littoral and Open Ocean. It also reports available studies concerning marine and freshwater plants exposed to UV irradiation.


Martins J.N.R.,New University of Lisbon
Journal of Clinical and Diagnostic Research | Year: 2014

The most common configuration of the maxillary first molar is the presence of three roots and four root canals, although the presence of several other configurations have already been reported. The objective of this work is to present a rare anatomic configuration with seven root canals diagnosed during an endodontic therapy. Endodontic treatment was performed using a dental operating microscope. Exploring the grooves surrounding the main canals with ultrasonic troughing was able expose unexpected root canals. Instrumentation with files of smaller sizes and tapers was performed to prevent root physical weakness. The anatomic configuration was confirmed with a Cone Beam Computer Tomography image analysis which was able to clearly show the presence of seven root canals. An electronic database search was conducted to identify all the published similar cases and the best techniques to approach them are discussed.


Chalub F.A.C.C.,New University of Lisbon | Souza M.O.,Federal University of Fluminense
Journal of Mathematical Biology | Year: 2014

We study a class of processes that are akin to the Wright-Fisher model, with transition probabilities weighted in terms of the frequency-dependent fitness of the population types. By considering an approximate weak formulation of the discrete problem, we are able to derive a corresponding continuous weak formulation for the probability density. Therefore, we obtain a family of partial differential equations for the evolution of the probability density, and which will be an approximation of the discrete process in the joint large population, small time-steps and weak selection limit. If the fitness functions are sufficiently regular, we can recast the weak formulation in a more standard formulation, without any boundary conditions, but supplemented by a number of conservation laws. The equations in this family can be purely diffusive, purely hyperbolic or of convection-diffusion type, with frequency dependent convection. The particular outcome will depend on the assumed scalings. The diffusive equations are of the degenerate type; using a duality approach, we also obtain a frequency dependent version of the Kimura equation without any further assumptions. We also show that the convective approximation is related to the replicator dynamics and provide some estimate of how accurate is the convective approximation, with respect to the convective-diffusion approximation. In particular, we show that the mode, but not the expected value, of the probability distribution is modelled by the replicator dynamics. Some numerical simulations that illustrate the results are also presented. © 2013 Springer-Verlag Berlin Heidelberg.


Weetman D.,Vector Group | Wilding C.S.,Vector Group | Steen K.,Vector Group | Pinto J.,New University of Lisbon | Donnelly M.J.,Vector Group
Molecular Biology and Evolution | Year: 2012

Anopheles gambiae sensu stricto exists as two often-sympatric races termed the M and S molecular forms, characterized by fixed differences at an X-linked marker. Extreme divergence between M and S forms at pericentromeric "genomic islands" suggested that selection on variants therein could be driving interform divergence in the presence of ongoing gene flow, but recent work has detected much more widespread genomic differentiation. Whether such genomic islands are important in reproductive isolation or represent ancestral differentiation preserved by low recombination is currently unclear. A critical test of these competing hypotheses could be provided by comparing genomic divergence when rates of recent introgression vary. We genotyped 871 single nucleotide polymorphisms (SNPs) in A. gambiae sensu stricto from locations of M and S sympatry and allopatry, encompassing the full range of observed hybridization rates (0-25%). M and S forms were readily partitioned based on genomewide SNP variation in spite of evidence for ongoing introgression that qualitatively reflects hybridization rates. Yet both the level and the heterogeneity of genomic divergence varied markedly in line with levels of introgression. A few genomic regions of differentiation between M and S were common to each sampling location, the most pronounced being two centromere-proximal speciation islands identified previously but with at least one additional region outside of areas expected to exhibit reduced recombination. Our results demonstrate that extreme divergence at genomic islands does not simply represent segregating ancestral polymorphism in regions of low recombination and can be resilient to substantial gene flow. This highlights the potential for islands comprising a relatively small fraction of the genome to play an important role in early-stage speciation when reproductive isolation is limited. © The Author 2011.


Larrinaga P.,Tecnalia | Chastre C.,New University of Lisbon | San-Jose J.T.,University of the Basque Country | Garmendia L.,Tecnalia
Composites Part B: Engineering | Year: 2013

The recent development of inorganic based composites as low-cost materials in reinforced concrete structural strengthening and precast thin-walled components, requires the creation of models that predict the mechanical behaviour of these materials. Textile Reinforced Mortar (TRM) shows complex stress-strain behaviour in tension derived from the heterogeneity of its constituent materials. This complexity is mainly caused by the formation of several cracks in the inorganic matrix. The multiple cracking leads to a decrease in structural stiffness. Due to the severe conditions of the serviceability limit state in structural elements, the prediction of the stress-strain curve is essential for design and calculation purposes. After checking other models, an empirical nonlinear approach, which is based on the crack control expression included in the Eurocode 2, is proposed in this paper. Following this scope, this paper presents an experimental campaign focused on 31 TRM specimens reinforced with four different reinforcing ratios. The results are analysed and satisfactorily contrasted with the presented non-linear approach. © 2013 Elsevier Ltd. All rights reserved.


Ferreira A.R.,University of Aveiro | Freire M.G.,University of Aveiro | Ribeiro J.C.,Galp Energia | Lopes F.M.,Galp Energia | And 2 more authors.
Industrial and Engineering Chemistry Research | Year: 2012

Many separation processes in petrochemical and refining industries are applied to close boiling point compounds and/or azeotropic mixtures which make difficult the application of simple distillation, requiring alternative separation processes. Ionic liquids, with their unique and tunable properties, may constitute an advantageous alternative as extractive solvents in separation processes that involve hydrocarbon systems. In this work, a review on the experimental data available for ternary systems composed of ionic liquids and hydrocarbons is reported. The gathered information was shown to be essential in the understanding of the molecular interactions and of the effect of the various structural features of both the ionic liquids and the hydrocarbons on their phase behavior, allowing the development of guidelines for the choice of the most suitable ionic liquid for hydrocarbon separation. To be able to carry out the design and selection of new and improved ionic liquids, the development of predictive models and their validation is required, since the experimental screening of the huge number of potential ionic liquids is not feasible. In this context, the ability of COSMO-RS (COnductor-like Screening MOdel for Real Solvents) as a predictive tool to describe the liquid-liquid equilibria of ternary systems composed of ionic liquids and hydrocarbons, is evaluated. The results obtained with COSMO-RS testify its ability for the qualitative, and in some cases the quantitative, description of the phase behavior of the systems studied. © 2012 American Chemical Society.


Pessoa M.F.,New University of Lisbon
Emirates Journal of Food and Agriculture | Year: 2012

This study provides an overview of the available literature on the ultraviolet-B (UV-B - λ=280-315 nm) and UV-A radiation (λ=315-400 nm) effects on algae (micro and macroalgae) and aquatic macrophytes, like seagrasses and liverworts. It includes studies on prokariotic cyanobacteria, haptophytes, diatoms, dinoflagellates, red algae, brown algae and chlorophytes from freshwater (ponds, lakes) to marine littoral and Open Ocean. It also reports available studies concerning on marine and freshwater plants exposed under UV irradiation. Since the reported relationship between the human activity and the depletion of the protecting layer, the effects of ultraviolet radiation in the biological relevant wavebands on algae and on organisms in general have become an important issue over the past three decades and will be also important in the next few decades. Virtually, all aquatic organisms depend on algae and aquatic plants (submerged or near shallow line) for food, shelter, also as oxygen supplement and CO2 sequestration by photosynthetic procedure. This review reports on harmfull effects caused by ultraviolet wavebands on photosynthetic organisms in their natural habitats.


Zlatev Z.,Agricultural University of Plovdiv | Lidon F.C.,New University of Lisbon
Emirates Journal of Food and Agriculture | Year: 2012

At a whole plant level the effects of drought is usually perceived as a decrease in growth and photosynthetic carbon assimilation. That is why this review is focused mainly on recent information about the effects of drought on plant growth, water relations and photosynthesis, as well as mechanisms of adaptation. It is shown that plants have evolved a great number of adaptive mechanisms that allow the biochemical systems to cope with increased water deficit. The literature analyzed in this review shows the complexity of tolerance to water deficit and supports the statements of many authors that the flexibility of cell metabolism and its fast acclimation to changes in environmental conditions is a first essential step in stress avoidance.


Indulkar U.U.,Institute of Chemical Technology | Kale S.R.,Institute of Chemical Technology | Gawande M.B.,New University of Lisbon | Jayaram R.V.,Institute of Chemical Technology
Tetrahedron Letters | Year: 2012

Nano zinc oxide (Nano-ZnO) was explored as a reusable catalyst for the enamination of 1,3-dicarbonyls using diverse amines. To make the process environmentally viable, the reaction was carried out under solvent-free conditions and found to give good yield of desired products. The catalyst was characterized by various analytical techniques such as UV-spectroscopy, XRD, and TEM. The catalyst was found to be reusable up to four catalytic cycles without any appreciable loss in activity. © 2012 Elsevier Ltd. All rights reserved.


Balbi S.,University of Venice | Giupponi C.,University of Venice | Perez P.,University of Wollongong | Alberti M.,New University of Lisbon
Environmental Modelling and Software | Year: 2013

A vast body of literature suggests that the European Alpine Region is amongst the most sensitive socio-ecosystems to climate change impacts. Our model represents the winter tourism socio-ecosystem of Auronzo di Cadore, located in the Dolomites (Italy), which economic and environmental conditions are highly vulnerable to climate variations. This agent-based model includes eight types of agents corresponding to different winter tourist profiles based on their socio-economic background and activity targets. The model is calibrated with empirical data while results are authenticated through direct interaction of local stakeholders with the model. The model is then used for assessing three hypothetical and contrasted infrastructure-oriented adaptation strategies for the winter tourism industry, that have been previously discussed with local stakeholders, as possible alternatives to the " business-as-usual" situation. These strategies are tested against multiple future scenarios that include: (a) future weather conditions in terms of snow cover and temperature, (b) the future composition and total number of tourists and (c) the type of market competition. A set of socio-economic indicators, which are strongly coupled with relevant environmental consequences, are considered in order to draw conclusions on the robustness of the selected strategies. © 2012 Elsevier Ltd.


Sousa S.C.A.,University of Lisbon | Bernardo J.R.,University of Lisbon | Romao C.C.,New University of Lisbon | Fernandes A.C.,University of Lisbon
Tetrahedron | Year: 2012

This work reports a novel method for the deoxygenation of aromatic and aliphatic sulfoxides catalyzed by oxo-rhenium complexes without adding any reducing agent. The oxo-rhenium complex ReOCl 3(PPh 3) 2 proved to be very efficient for the deoxygenation of several sulfoxides with tolerance of different functional groups. © 2012 Elsevier Ltd. All rights reserved.


Kale S.R.,Institute of Chemical Technology | Kahandal S.S.,Institute of Chemical Technology | Burange A.S.,Institute of Chemical Technology | Gawande M.B.,New University of Lisbon | Jayaram R.V.,Institute of Chemical Technology
Catalysis Science and Technology | Year: 2013

A simple and environmentally benign synthesis of 2-amino-4H-chromene is described using hydrotalcite as a solid base catalyst in aqueous medium. The catalysts were prepared by a co-precipitation method and well characterized by various techniques such as XRD, FT-IR, SEM and the basicity was found using the phenol adsorption method. The reusability of the catalyst, use of water as a green solvent and easy isolation of the product along with good yields make the present protocol sustainable and advantageous compared to conventional methods. This journal is © 2013 The Royal Society of Chemistry.


Scheven U.M.,New University of Lisbon
Physical Review Letters | Year: 2013

We show that transverse dispersion in flow through randomly packed monodisperse spheres (sphere diameter d) is a velocity-dependent superposition of three separable random processes - diffusion with coefficient Dr, intrinsic mechanical dispersion with dispersivity lm=d/33 caused by advection on streamlines, and a newly identified coupled mechanical dispersion with dispersivity lc=d/11, which arises by coupled advection and transverse diffusion at the pore scale. The velocity dependence of the transverse dispersivity is derived from first principles. Our analysis is insensitive to details of the pore geometry and is verified by pulsed field gradient NMR experiments which covered 4.5 orders of magnitude in reduced velocity. © 2013 American Physical Society.


Oliveira G.,University of Lisbon | Costa A.,Instituto Nacional Of Recursos Biologicos Ip L Inia | Costa A.,New University of Lisbon
Forest Ecology and Management | Year: 2012

Cork oak (Quercus suber L.) woodlands are ecologically sensitive and human-supported areas which strongly rely on the high market value of cork for their sustainability. Cork harvesting is a forestry practice specific to this Mediterranean evergreen oak, whereby the bark (cork) is periodically removed from stems and branches over the whole tree lifetime. This practice is a strain factor for the tree, particularly because it is performed during the most stressful time of the year, and also because stripped oaks become more vulnerable to pathogens and environmental hazards such as wildfires.This review gathers and analyzes information about tree responses to cork harvesting. Cork removal leads to phellogen destruction and subsequent regeneration. Upon each harvesting, the tree faces important losses of water, released from the suddenly exposed living cells, and of cork. Immediate responses relate to stem healing mechanisms, leaf stomatal closure and prompt production of new cork layers by the restored phellogen, the latter actually representing the most evident response of Q. suber to cork harvesting. Further strategies to compensate for water and cork losses are insufficiently understood, but possibly include prolonged reduction of leaf transpiration (and consequent reduction of photoassimilation), increased water uptake from the soil, use of reserves and changes in whole-tree energy allocation to support cork regeneration.Cork stripping by unskilled workers may leave wounds on the tree, which eventually hinder cork regeneration and lead to premature tree death.The relationship between current cork harvesting practices (e.g. harvesting intensities or periodicity) and tree resilience is not quite established. Higher stripping pressures seem to trigger more pronounced or drastic tree responses and/or to enhance their decline.A major conclusion is that the available information is still too scarce to allow for a consistent evaluation of the effects of cork harvesting on cork oak and on its associated woodlands. So far, few studies have addressed how tree resilience relates to harvesting intensities, a crucial issue to enable improved tree and stand management strategies and to ensure adequate conservation of these sensitive forest systems. © 2012 Elsevier B.V.


Lobo L.S.,New University of Lisbon
Catalysis Reviews - Science and Engineering | Year: 2013

Carbon gasification is an important reaction in industrial processes, energy generation processes, and diesel soot reduction. The observed kinetics are briefly reviewed, both in non porous and porous materials. The cases of combustion of graphite, coal, char, coke and diesel fuel soot are compared. A review of the proposed mechanisms is done with an emphasis in carbon bulk diffusion, using Fick's Law to articulate the carbon bulk diffusion step with the other steps. The relevance of the Hedvall effect and the Tammann temperature in transition metals is addressed, including a discussion about the relation between mechanistic models and phenomenological models. © 2013 Copyright Taylor and Francis Group, LLC.


Santos D.M.F.,University of Lisbon | Saturnino P.G.,University of Lisbon | Lobo R.F.M.,New University of Lisbon | Sequeira C.A.C.,University of Lisbon
Journal of Power Sources | Year: 2012

Direct borohydride fuel cells (DBFCs) are receiving much attention during the last decade. Many researchers are now focused on DBFCs operating on sodium borohydride (NaBH 4) as the fuel and hydrogen peroxide (H 2O 2) as the oxidant. In the present work, direct NaBH 4/H 2O 2 fuel cells consisting of platinum (Pt) anodes, a Prussian Blue (PB)-coated Pt or a Pt cathode, and a Nafion N117 membrane as the separator, are assembled. The effect of different operational conditions, namely the fuel (NaBH 4 + NaOH) and oxidant (H 2O 2 + HCl) compositions, as well as the operation temperature, on the performance of these DBFCs is investigated. The obtained results are evaluated and the most suitable conditions for the operation of these NaBH 4/H 2O 2 systems are proposed. The use of the PB-coated electrode can lead to up to a 50% increase in the peak power density, as compared to the cell using a single Pt cathode. At 65 °C, the DBFC using the PB-modified electrode attained over 200 mW cm -2, at a cell voltage of 0.8 V. © 2011 Elsevier Ltd. All rights reserved. All rights reserved.


Dagorne S.,CNRS Strasbourg Institute of Chemistry | Fliedel C.,New University of Lisbon
Topics in Organometallic Chemistry | Year: 2013

This chapter highlights the most recent and representative results on the use of organoaluminum compounds in polymerization catalysis with a special emphasis on discrete Al-incorporating catalysts. The first part of this contribution summarizes recent and noteworthy developments on well-defined Al-based initiators for the controlled (and stereocontrolled) polymerization of various monomers including isobutene, styrene, epoxides, methyl methacrylate, cyclic esters, and cyclic carbonates. The second part discusses the latest significant advances on the synthesis and structural characterization of polynuclear organoaluminum/transition (and f-block) metal complexes relevant to Ziegler-Natta-type catalysis. Graphical Abstract: © Springer-Verlag Berlin Heidelberg 2012.


Amaral L.,New University of Lisbon | Molnar J.,University of Szeged
Expert Review of Anti-Infective Therapy | Year: 2012

Over a period of 14 years, the authors have studied thioridazine, an old neuroleptic, that has been shown to have in vitro activity against intracellular Mycobacterium tuberculosis, regardless of its antibiotic resistance status, thioridazine cures infected mice of antibiotic-susceptible and multidrug-resistant tuberculosis (TB) infections and, when used in combination with antibiotics used for therapy of TB, renders the organism significantly more susceptible. This article will describe the authors' further work and the mechanisms by which thioridazine alone and in combination with antibiotics cures an extensively drug-resistant infection and why it is expected to cure totally drug-resistant TB infections as well. The concepts presented are entirely new and because they focus on the activation of killing by nonkilling macrophages where M. tuberculosis normally resides during infection, and coupled to the inhibition of efflux pumps which contribute to the antibiotic-resistant status, effective therapy of any antibiotic-resistant TB infection is possible. © 2012 2012 Expert Reviews Ltd.


Globally, tuberculosis infections continue to increase their resistance to antibioti+cs. Multidrug resistant tuberculosis infections (MDR TB) have progressed to extensively drug resistance status (XDR TB) and the latter have evolved in some parts of the world to totally drug resistant (TDR TB) infections. MDR TB is difficult to treat successfully, and when therapy is ineffective, a single case can cost almost $500,000. When the infection is XDR TB therapy is mostly unsuccessful and is accompanied with high mortality. TDR TB-a yet to be defined infection, is resistant to all forms of therapy and mortality is almost certain. We have, over a period of 14 years, studied thioridazine (TZ) an old neuroleptic that we have shown to: i) have in vitro activity against all antibiotic resistant forms of Mycobacterium tuberculosis; ii) have activity against intracellular Mycobacterium tuberculosis regardless of its antibiotic resistance status; iii) cure the infected mouse of an antibiotic susceptible and MDR TB infections; and, iv) when used in combination with antibiotics used for therapy of tuberculosis, would render the organism significantly more susceptible. These studies have guided our Argentinian colleagues to treat successfully XDR TB infections with thioridazine in combination with three antibiotics to which the infection was initially resistant. This mini review will describe our further work and the mechanisms by which TZ alone and in combination with antibiotics cures an XDR TB infection and why it is expected to cure TDR TB infections as well. The concepts presented are totally new and because they focus on the activation of killing by non-killing macrophages where Mycobacterium tuberculosis normally resides during infection, and coupled to the inhibition of efflux pumps which contribute to the antibiotic resistant status, effective therapy of any antibiotic resistant TB infection is possible. Because TZ is cheap and therefore affordable to any economically disadvantaged country, and will produce no harm when appropriate measures are taken, it is the ideal drug for immediate use in countries that have high frequencies of MDR, XDR and TDR TB infections. © Ordem dos Médicos 2012.


Bernardes C.E.S.,University of Lisbon | Minas Da Piedade M.E.,University of Lisbon | Canongia Lopes J.N.,University of Lisbon | Canongia Lopes J.N.,New University of Lisbon
Journal of Physical Chemistry B | Year: 2012

A molecular dynamics simulation study of the two known polymorphs of 4′-hydroxyacetophenone (HAP; form I, monoclinic; form II, orthorhombic) is described. The modeling of the lattice energetics was found to be particularly sensitive to the atomic point charge (APC) selection method, to the number of molecules in the asymmetric unit (Z′), and to the flexibility allowed for the molecules. In order to improve the quality of the APCs, a new strategy that attempts to simulate the polarizability effects of the molecules in the crystal lattice was developed. This method relies in the application of the CHelpG methodology to a molecular aggregate with the same spatial arrangement present in the crystal lattice of the compound. This approach led to δtrsHm o(II→I) = +2.4 ± 0.3 kJ•mol-1 and δtrsHm o(II→I) = +2.0 ± 0.9 kJ•mol-1 when rigid and flexible models were used, respectively, in good agreement with the corresponding experimental value δtrsHm o(II→I) = +0.49 ± 0.13 kJ•mol-1. Concerning the volumetric properties (density and unit cell parameters), it was concluded that the use of a flexible molecular model was largely insensitive to the chosen methodology for the selection of the APC. Overall, it was concluded that the best performance in the prediction of the energetic and volumetric properties of the two HAP polymorphs was achieved by combining a flexible molecular framework with atomic charges obtained for a molecular aggregate mimicking the crystal packing. © 2012 American Chemical Society.


Thiela A.,Humboldt University of Berlin | Egerton C.,New University of Lisbon
Journal of Environmental Planning and Management | Year: 2011

The paper complements work on the re-scaling of resource governance by developing a theoretical understanding based on the distributional theory of institutional change, and by examining the case of water governance in Portugal. Different from the reactions of other European Member States to the Water Framework Directive, the central water authority and multi-sectoral deconcentrated administrations lost competencies in favour of new water administrations. The level of water governance shifted from administrative districts to hydrographic regions. Significant players in this process were the central state and the Minister of the Environment. Our explanation considers time preferences, mental models, credibility and transaction and transition costs of governance, which affected the timing and content of the reform, and the paper compares the situation to the rest of Europe. © 2011 University of Newcastle upon Tyne.


Shimizu K.,University of Lisbon | Bernardes C.E.S.,University of Lisbon | Triolo A.,CNR Institute of Structure of Matter | Canongia Lopes J.N.,University of Lisbon | Canongia Lopes J.N.,New University of Lisbon
Physical Chemistry Chemical Physics | Year: 2013

The present study analyses the large structural differences, first observed using X-ray diffraction, between 1-alkyl-3-methylimidazolium-based ionic liquids, [Cnmim][Ntf2] (n = 3, 6, 9), and their counterparts with ether-substituted alkyl side chains, [(C1OC 1)(n/3)mim][Ntf2] (n = 3, 6, 9). The MD simulations - obtained using a non-polarizable atomistic force-field to model the ionic liquids under discussion - demonstrate that the suppression of the nanostructured nature in the ionic liquids with ether chains is persistent along the entire series and it is not due to any modification of the polar network of the ionic liquid but rather due to the different morphologies of the non-polar regions that surround it. The modification of the non-polar regions - shift from bulky segregated domains in [Cnmim][Ntf2] to thin enveloping ones in [(C1OC1)(n/3)mim][Ntf 2] - are caused by the inability of the oxygen-substituted alkyl side chains to pack effectively side by side, the existence of kinks along the chain that lead eventually to intra-molecular, scorpion-like interactions between the chains and the imidazolium ring, and by their stronger interactions with the cations of the polar network via the lone electron pairs of the ether oxygen atoms. © 2013 The Owner Societies.


Madeira A.,University of Lisbon | Moura T.F.,University of Lisbon | Moura T.F.,New University of Lisbon | Soveral G.,University of Lisbon
Cellular and Molecular Life Sciences | Year: 2015

Aquaporins (AQPs) are membrane water/glycerol channels that are involved in many physiological processes. Their primary function is to facilitate the bidirectional transfer of water and small solutes across biological membranes in response to osmotic gradients. Aquaglyceroporins, a subset of the AQP family, are the only mammalian proteins with the ability to permeate glycerol. For a long time, AQP7 has been the only aquaglyceroporin associated with the adipose tissue, which is the major source of circulating glycerol in response to the energy demand. AQP7 dysregulation was positively correlated with obesity onset and adipocyte glycerol permeation through AQP7 was appointed as a novel regulator of adipocyte metabolism and whole-body fat mass. Recently, AQP3, AQP9, AQP10 and AQP11 were additionally identified in human adipocytes and proposed as additional glycerol pathways in these cells. This review contextualizes the importance of aquaglyceroporins in adipose tissue biology and highlights aquaglyceroporins' unique structural features which are relevant for the design of effective therapeutic compounds. We also refer to the latest advances in the identification and characterization of novel aquaporin isoforms in adipose tissue. Finally, considerations on the actual progress of aquaporin research and its implications on obesity therapy are suggested. © 2014 Springer Basel.


Neto N.,University of Lisbon | Neto N.,New University of Lisbon | Brito J.D.,University of Lisbon
Construction and Building Materials | Year: 2012

Based on a proposal for a classification system for anomalies and their probable causes in natural stone cladding (NSC) an inspection plan was developed for recent buildings with anomalies in this type of cladding, to validate the system. This field work generated data from 59 buildings whose cladding exhibited various anomalies, in a grand total of 288. A specific area of Lisbon city (Portugal) was selected for most of the inspections: The Parque das Naões - an urban area that was regenerated for the Expo'98 World's Fair. Based on these inspections, a comparative analysis was performed on various surfaces clad in this material, i.e. pavements versus walls and indoor versus outdoor applications. The resulting data underwent a statistical analysis and post-treatment, providing conclusions that could lead to actions to prevent degradation of this type of cladding and its substrate, with the aim of achieving a better quality and less costly built environment. © 2011 Elsevier Ltd. All rights reserved.


Bras A.,Polytechnic Institute of Setubal | Henriques F.M.A.,New University of Lisbon
Construction and Building Materials | Year: 2012

The goal of this research was to develop a methodology for grout composition optimization concerning specific applications. It could be developed for masonry consolidation or bonded prestressed tendon grout, pre-placed aggregate grout, among others. The grout development does not only depend on its intrinsic properties but also on the nature and features of the support. The purpose of a grout injection technique applied in a multiple leaf wall is to increase the compactness and create links between the internal and external leaves, which improve not only shear and flexural resistance but also the compressive strength. In practice, the variability of voids within masonries requires an ability to fine tune the rheological properties of the grout in order to optimally fill the voids. The methodology proposed here for testing grout injectability in a porous media like masonry is a logical tool to use in grout optimization. It shows that several grout parameters should be controlled for a successful injection. Concerning the support and its typology, the mortar between stones plays a fundamental role in the effectiveness of the intervention, due to its reduced porosity and composition. Besides that, earth and mortar, for example, can be present in the interior of masonry and make difficult, with their absorption, the injection. Thus, the water retention capacity of grout should be controlled to prevent that problem, as it was made in this work, using the optimized mixing procedure that takes into account that and other fresh grout properties. This study analyses some relevant grout properties such as yield stress, plastic viscosity, flowability and injectability for natural hydraulic lime based grouts in different porous media. The research shows that there are differences in the grout behaviour, especially in rheological properties, when different mixing procedures and/or grout composition (different water/binder or fly ash/binder ratios) are used and that fresh grout properties may be optimized for injection purpose. © 2011 Elsevier Ltd. All rights reserved.


Ludovico-Marques M.,Polytechnic Institute of Setubal | Chastre C.,New University of Lisbon | Vasconcelos G.,University of Minho
Construction and Building Materials | Year: 2012

Building stones, particularly sandstone and granite, are very important in the building elements of Portugal's historical and cultural heritage. Experimental research, based on uniaxial compressive tests, was carried out on selected representative samples of lithotypes of rocks used in historic built heritage, with a view to evaluating the compressive mechanical behaviour of different building stones. The results showed that porosity plays a central role in the compressive behaviour of granites and sandstones. As porosity can be evaluated in field conditions with non-destructive tests it was decided to derive an analytical model to predict compressive behaviour based on the knowledge of porosity of the building stones. A cubic polynomial function was adopted to describe the pre-peak regime under compression to implement the model. Furthermore, a statistical correlation between mechanical and porosity data had to be defined. Good agreement between experimental and analytical compressive stress-strain diagrams, from which the mechanical properties like compressive strength and modulus of elasticity can be derived, was achieved. © 2011 Elsevier Ltd. All rights reserved.


Round-robin characterization is reported on the sputter depth profiling of CrN/AlN multilayer thin-film coatings on nickel alloy by secondary ion mass spectrometry (SIMS) and glow-discharge optical emission spectrometry (GD-OES). It is demonstrated that a CAMECA SIMS 4550 Depth Profiler operated with 3 keV O 2+ primary ions provides the best depth resolution and sensitivity. The key factor is sample rotation, which suppresses the negative influence of the surface topography (initial and ion-induced) on the depth profile characteristics. © 2010 Pleiades Publishing, Ltd.


Barcia P.,New University of Lisbon | Pestana R.,REN - Rede Electrica Nacional
International Journal of Electrical Power and Energy Systems | Year: 2010

Consider an electrical power system and let G denote the set of nodes with net generation, L the set of nodes with a net load and assume the DC model of the network. Our aim is to determine how much power is each node of G sending to each node of L in such a way that the flow decomposition arising from this assignment is such that each branch flow is broken in parcels of the (as much as possible) same orientation in order to provide a sensible tool for transmission cost allocation. © 2009 Elsevier Ltd. All rights reserved.


Faria Martins J.,New University of Lisbon | Picken R.,University of Lisbon
Differential Geometry and its Application | Year: 2011

We define the thin fundamental Gray 3-groupoid S3(M) of a smooth manifold M and define (by using differential geometric data) 3-dimensional holonomies, to be smooth strict Gray 3-groupoid maps S3(M)→C(H), where H is a 2-crossed module of Lie groups and C(H) is the Gray 3-groupoid naturally constructed from H. As an application, we define Wilson 3-sphere observables. © 2010 Elsevier B.V.


Sauer A.,RWTH Aachen | Kapelski A.,RWTH Aachen | Fliedel C.,CNRS Strasbourg Institute of Chemistry | Fliedel C.,New University of Lisbon | And 3 more authors.
Dalton Transactions | Year: 2013

Polylactide (PLA) is an attractive polymeric material due to its origin from annually renewable resources and its biodegradability. The ring-opening polymerization (ROP) of lactide initiated by Lewis acidic and oxophilic metal-based catalysts constitutes the method of choice to access PLA in a controlled and stereoselective manner. The design and synthesis of ligand-supported metal complexes to act as effective ROP initiators of lactide monomers have been the subject of numerous investigations over the past decades. In view of their oxophilic nature, well-defined group 4 metal complexes supported by polydentate supporting ligands have appeared as active initiators for lactide ROP. This perspective summarizes various classes of structurally well-defined group 4 metal initiators developed for lactide ROP. It also provides observed trends regarding their catalytic performance. Whenever appropriate and possible, catalyst structure-ROP performance (i.e. activity, control and stereoselectivity) relationships are rationalized. © 2013 The Royal Society of Chemistry.


Eisen A.,University of British Columbia | Eisen A.,University of Sydney | Eisen A.,New University of Lisbon
Journal of neurology, neurosurgery, and psychiatry | Year: 2014

The onset of amyotrophic lateral sclerosis (ALS) is conventionally considered as commencing with the recognition of clinical symptoms. We propose that, in common with other neurodegenerations, the pathogenic mechanisms culminating in ALS phenotypes begin much earlier in life. Animal models of genetically determined ALS exhibit pathological abnormalities long predating clinical deficits. The overt clinical ALS phenotype may develop when safety margins are exceeded subsequent to years of mitochondrial dysfunction, neuroinflammation or an imbalanced environment of excitation and inhibition in the neuropil. Somatic mutations, the epigenome and external environmental influences may interact to trigger a metabolic cascade that in the adult eventually exceeds functional threshold. A long preclinical and subsequent presymptomatic period pose a challenge for recognition, since it offers an opportunity for protective and perhaps even preventive therapeutic intervention to rescue dysfunctional neurons. We suggest, by analogy with other neurodegenerations and from SOD1 ALS mouse studies, that vulnerability might be induced in the perinatal period. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.


Avo J.,New University of Lisbon
Synlett | Year: 2011

(A) Mannich-Type Synthesis of Propargylamines: Bieber and da Silva reported a mild, easy, and efficient synthesis of propargylamines by copper I) iodide catalyzed Mannich reaction of terminal alkynes with aqueous formaldehyde and secondary amines. The aminomethylation was conducted in DMSO and high to quantitative yields were obtained.(B) Synthesis of Mannich Bases Related to Gramine: Indoles have potent biological activity and are one of the most important subjects in heterocyclic chemical research. The preparation of several gramines by Mannich reaction of paraformaldehyde, a secondary amine and indole/N-methylindole was reported by Dai et al. Using zinc(II) chloride as mediator, the indoles were obtained in 58-98% yields.(C) Piperazines by Ugi Four-Component Condensation: Giovenzana et al. described the preparation of diamines by modified Ugi four-component reaction of several isocyanides, paraformaldehyde carboxylic acids, and diamines. The method was particularly useful in the preparation of piperazines in methanolic solution, and good to quantitative yields were achieved. In addition, the authors extended the applicability of the Ugi multicomponent reaction in synthetic and medicinal chemistry research.(D) Solvent-Free, Microwave-Assisted Synthesis of Phosphono- and Phosphinoxidomethylated N-Heterocycles: Keglevich and co-workers prepared N-phosphono and N-phosphinoxi derivatives from the condensation of paraformaldehyde, Nheterocycles and diethylphosphite or diphenylphosphine. The reactions were conducted in environmentally friendly manner under solvent-free, microwave-assisted conditions, representing a green alternative to traditional techniques. A variety of N-phospho derivatives was swiftly synthesized in high yields (70-92%) with excellent purity levels.(E) Diastereoselective Synthesis of Pyrrolidines by Horner-Wadsworth-Emmons Olefination: In the reported synthesis, oxoalkanoates undergo reaction with hexyl- or benzylamines to yield phosphorylpyrrolidinones. The Horner-Wadsworth-Emmons olefination of these intermediates with paraformaldehyde yields 60-95% of pyrrolidinones with excellent diastereoselectivity.(F) Synthesis of 1,3-Dioxanes via Prins Reaction: 1,3- ioxanes are important compounds in drug discovery, displaying potent biological activity. Recently, Yadav et al. reported a new eco-friendly method for the preparation of 1,3-dioxane derivatives using molecular iodine as catalyst. The Prins reaction of a variety of alkyl- or aryl-substituted alkenes with paraformaldehyde afforded a library of these compounds in excellent yields.(G) Glycosyls via Diels-Alder Reaction: Vankar and co-orker described the synthesis of C-glycosyl aminoacids via Diels-Alder reaction of methyl nitroacetate and formaldehyde generating in situ a-nitro methyl acrylate, with glucal dienes. Single-pot reduction and acetylation of the resulting cycloadducts afforded the glycosyls in good yields with considerable stereoselectivity (85:15). This class of compounds is target of extensive research in drug discovery due to its biological properties. © Georg Thieme Verlag Stuttgart.


Povoa P.,Polyvalent Intensive Care Unit | Povoa P.,New University of Lisbon | Salluh J.I.F.,DOr Institute for Research and Education | Salluh J.I.F.,Instituto Nacional Of Cancer
Current Opinion in Infectious Diseases | Year: 2012

PURPOSE OF REVIEW: This review evaluates the potential benefits as well as adverse effects from adjunctive therapy with systemic steroids in patients with pneumonia: either mild-to-moderate or severe, community-acquired or hospital-acquired, of bacterial or of viral origin (in particular H1N1 viral infection). RECENT FINDINGS: Steroids potentially modulate the marked and persistent activation of the immune system in pneumonia. However, several recent randomized controlled trials and large prospective observational studies have repeatedly shown that steroids had no impact on survival, the clinical event of interest, but in severe pneumonia some studies pointed to potential harmful effect. In addition, adverse effects, namely hyperglycemia, superinfections, as well as increased length-of-stay, were frequent findings in the steroid-treated patients. SUMMARY: According to the current evidence, there are no data to support the well tolerated use of systemic steroids as a standard of care in pneumonia, neither in mild-to-moderate and severe, nor in bacterial and viral infection. Clinical and basic research should work together to improve trial designs to identify reliable surrogate markers of outcome, in particular of mortality. This may improve the patient selection and facilitate the identification of subgroups that can benefit from adjunctive steroid therapy. © 2012 Lippincott Williams & Wilkins, Inc.


Zanin M.,Innaxis Foundation and Research Institute | Zanin M.,Polytechnic University of Mozambique | Zanin M.,New University of Lisbon | Lillo F.,Normal School of Pisa | Lillo F.,Santa Fe Institute
European Physical Journal: Special Topics | Year: 2013

Air transport is a key infrastructure of modern societies. In this paper we review some recent approaches to air transport, which make extensive use of theory of complex networks. We discuss possible networks that can be defined for the air transport and we focus our attention to networks of airports connected by flights. We review several papers investigating the topology of these networks and their dynamics for time scales ranging from years to intraday intervals, and consider also the resilience properties of air networks to extreme events. Finally we discuss the results of some recent papers investigating the dynamics on air transport network, with emphasis on passengers traveling in the network and epidemic spreading. © 2013 EDP Sciences and Springer.


Ferreira da Silva A.R.,New University of Lisbon
Journal of Statistical Software | Year: 2011

Graphic processing units (GPUs) are rapidly gaining maturity as powerful general parallel computing devices. A key feature in the development of modern GPUs has been the advancement of the programming model and programming tools. Compute Unied Device Architecture (CUDA) is a software platform for massively parallel high-performance computing on Nvidia many-core GPUs. In functional magnetic resonance imaging (fMRI), the volume of the data to be processed, and the type of statistical analysis to perform call for high-performance computing strategies. In this work, we present the main features of the R-CUDA package cudaBayesreg which implements in CUDA the core of a Bayesian multilevel model for the analysis of brain fMRI data. The statistical model implements a Gibbs sampler for multilevel/hierarchical linear models with a normal prior. The main contribution for the increased performance comes from the use of separate threads for tting the linear regression model at each voxel in parallel. The R-CUDA implementation of the Bayesian model proposed here has been able to reduce signicantly the run-time processing of Markov chain Monte Carlo (MCMC) simulations used in Bayesian fMRI data analyses. Presently, cudaBayesreg is only congured for Linux systems with Nvidia CUDA support.


Recchi C.,Imperial College London | Seabra M.C.,Imperial College London | Seabra M.C.,New University of Lisbon
Biochemical Society Transactions | Year: 2012

Rab GTPases are master regulators of intracellular trafficking and, in recent years, their role in the control of different aspects of tumour progression has emerged. In the present review, we show that Rab GTPases are disregulated in many cancers and have central roles in tumour cell migration, invasion, proliferation, communication with stromal cells and the development of drug resistance. As a consequence, Rab proteins may be novel potential candidates for the development of anticancer drugs and, in this context, the preliminary results obtained with an inhibitor of Rab function are also discussed. © 2010 The Author(s).


Costa A.C.,New University of Lisbon | Soares A.,University of Lisbon
Journal of Arid Environments | Year: 2012

Increased aridity is a robust proximate cause of desertification, both indirectly through greater rainfall variability and directly through prolonged droughts. The south of continental Portugal has large areas with high susceptibility to desertification. This study evaluates local dynamics in dryness in the south of Portugal based on the Aridity Intensity Index (AII), which is a numerical indicator of the degree of dryness of the climate and an indirect indicator of soil moisture availability. The AII was computed using daily precipitation data from stations with records within the 1940-1999 period in the south of Portugal. Annual scenarios of the AII were generated from 1940 to 1999 using direct sequential simulation (DSS). Those scenarios were then used to produce an additional set of maps that summarize their underlying space-time patterns. Two desertification indicators accounting for local dryness dynamics are proposed, namely the Dryness Susceptibility Indicator and the Dryness Trend Indicator. The results show that the southeast region is the most threatened by droughts and extreme dryness. Moreover, there is a tendency towards drier climatic conditions in coastal areas and in the centre of the study region. These findings are likely to have profound implications in agricultural planning and water supply management. © 2012 Elsevier Ltd.


Capinha C.,University of Evora | Anastacio P.,University of Evora | Tenedorio J.A.,New University of Lisbon
Biological Invasions | Year: 2012

In an effort to predict the impact of climate change on the distribution of existing invasive species, niche-based models (NBMs) are being increasingly used to make forecasts. Here, we investigate the reliability of these models in predicting future climatic suitability for 4 invasive decapods of the Iberian Peninsula: Cherax destructor, Eriocheir sinensis, Pacifastacus leniusculus and Procambarus clarkii. From an ensemble of forecasts generated by 5 distinct algorithms (generalized linear models, artificial neural networks, support vector machines, random forests and alternating decision trees), we calculated consensus predictions for current conditions and 3 future time periods (2030, 2050 and 2080) under low and high scenarios of greenhouse gas emissions. Three criteria were examined to infer the robustness of the forecasts: ability to predict current distributions, inter-model variability and degree of environmental extrapolation. Our results indicate an overall decline in climatic suitability for the 4 invaders as time progresses. However, we also identified highly distinct levels of predictive uncertainty among species. Good indicators of reliability were found for Procambarusclarkii and Pacifastacusleniusculus, whereas the predictions for C. destructor showed low predictive performance, low inter-model agreement and wide areas of environmental extrapolation. For E. sinensis, the models also showed high variability with respect to areas projected to lose climatic suitability. Overall, our results highlight the need to consider and evaluate multiple sources of uncertainty when using NBM predictions for invaders under current and future conditions. © 2012 Springer Science+Business Media B.V.


Pereira M.F.,University of Evora | Castro A.,University of Huelva | Chichorro M.,New University of Lisbon | Fernandez C.,University of Huelva | And 3 more authors.
Gondwana Research | Year: 2014

In the Southern Pyrenees there are Upper Carboniferous-Lower Permian sedimentary basins with a significant volume of volcanic material derived from explosive eruptions (rhyolitic ignimbrites and andesitic flows). These basins are spatially associated with granodiorites and dacitic dykes emplaced in Variscan basement rocks. U-Pb SHRIMP dating of zircons extracted from three granodiorites, an andesitic flow, a dacitic dyke and six ignimbrites, revealed that magmatism occurred over an extended period of thirty eight million years, from ca. 304. Ma to ca. 266. Ma (Upper Carboniferous-Middle Permian). A scattering of zircon ages in each sample shows that the history of melt crystallization was complex, with more than one zircon-forming event in each magma chamber. The prolonged crystallization history was transferred to the product of the eruptions. A chronological link between the deep-seated magma chambers and processes in eruptions was identified on the basis of four overlapping intervals at: ca. 309-307. Ma (Upper Carboniferous), ca. 304-296. Ma (Upper Carboniferous-Lower Permian), ca. 294-282. Ma (Lower Permian), and ca. 276. Ma (Lower Permian). The variation of zircon U/Th ratios exposes a tendency for an increase in mafic sources as crystallization advances in the Permian. Zircons probably crystallized from melt phases related to both a felsic-intermediate metaluminous source from ca. 310-293. Ma (mostly 0.1. <. Th/U. <. 0.6) to ca. 289-273. Ma (especially in the range 0.6. <. Th/U. <. 1) and a mafic source (mostly 1.2. <. Th/U. <. 1) at ca. 266-265. Ma. U-Pb zircon ages from volcanic and plutonic rocks of the Southern Pyrenees are consistent with the ages of the post-Variscan magmatism of Iberia associated with orocline generation and subduction of the Paleotethys Ocean (ca. 304-283. Ma), and in addition reveal a later magmatic event at ca. 276-266. Ma (Lower-Middle Permian). The location of the Iberian orocline in the core of Pangaea and near the western end of the subduction zone of the Paleotethys Ocean leads to the hypothesis that this later magmatic activity of the Southern Pyrenees could provide the missing link between the Variscan and Cimmerian cycles that acted sequentially in Permo-Carboniferous times. © 2013 International Association for Gondwana Research.


Nina J.,Centro Hospitalar Lisbon Ocidental | Nina J.,New University of Lisbon
Acta Medica Portuguesa | Year: 2014

Ebolavirosis, like Marburgvirosis, are African zoonosis, and for both the primary animal reservoir are bats. It is a typical acute haemorrhagic fever, characterized by a high lethality rate. In an outbreak, the human index case became infected after contact with an infected animal or its blood, in most cases during hunting. Secondary human cases became infected after close contact with another human case, with infected human fluids or with a recent dead corps of a human case. These viruses are easily transmitted by direct contact or by contact with patient body fluids, mainly blood. As such, health professionals working under suboptimal conditions usually constitute a large share of Ebola victims. At the moment, the treatment is only supportive, but several drugs are almost ready to be tried in human trials. There is no vaccine approved, but again there are several very promising in the pipeline. © Ordem dos Médicos 2014.


Grosso N.,New University of Lisbon | Paronis D.,Institute for Space Applications and Remote Sensing
Atmospheric Research | Year: 2012

Current satellite aerosol retrieval products could be complemented by contrast reduction methods to overcome limitations regarding highly reflective or heterogeneous surfaces such as urban, desert or snow covered areas. Algorithms based on the contrast reduction principle, define contrast loss in an image, inside a pre-determined window size, as an exponential function of the Aerosol Optical Thickness (AOT) difference between two images (a reference and a polluted) acquired under similar observation geometry conditions. This paper presents a contrast reduction algorithm designed for the MODIS sensor, based on the Differential Texture Analysis (DTA) approach. It focuses on algorithm optimization by: a) determining an optimal AOT spatial resolution; b) constraining the relative observation geometry differences between polluted and reference images; and c) assessing the influence of several land cover classes on the accuracy of the retrievals. A comparison of the results obtained for 192 images acquired for the year 2005 with data from five European AERONET stations is performed to assess overall algorithm accuracy as well as the impact of the proposed improvements. Comparative analysis of the results for the various sites showed an optimal algorithm performance for MODIS images using a 39. pixel distance window, composed of only forest and urban pixels. Comparison with AERONET AOT data showed a good agreement with a correlation coefficient of 0.78. A similar correlation is found when comparing AERONET measurements and MODIS aerosol standard product. This research supports the establishment of contrast reduction methods as a potential complement to other aerosol retrieval methodologies. Future work will aim at removing the residual aerosol influence from reference images, including BRDFs to better reproduce surface heterogeneity and observation geometry influences and expanding the scope of this study to other AERONET sites so as to further test the algorithm at a global scale. © 2011 Elsevier B.V.


Carvalho A.M.,Polytechnic Institute of Braganca | Frazao-Moreira A.,New University of Lisbon
Journal of Ethnobiology and Ethnomedicine | Year: 2011

Many European protected areas were legally created to preserve and maintain biological diversity, unique natural features and associated cultural heritage. Built over centuries as a result of geographical and historical factors interacting with human activity, these territories are reservoirs of resources, practices and knowledge that have been the essential basis of their creation. Under social and economical transformations several components of such areas tend to be affected and their protection status endangered.Carrying out ethnobotanical surveys and extensive field work using anthropological methodologies, particularly with key-informants, we report changes observed and perceived in two natural parks in Trás-os-Montes, Portugal, that affect local plant-use systems and consequently local knowledge. By means of informants' testimonies and of our own observation and experience we discuss the importance of local knowledge and of local communities' participation to protected areas design, management and maintenance. We confirm that local knowledge provides new insights and opportunities for sustainable and multipurpose use of resources and offers contemporary strategies for preserving cultural and ecological diversity, which are the main purposes and challenges of protected areas. To be successful it is absolutely necessary to make people active participants, not simply integrate and validate their knowledge and expertise. Local knowledge is also an interesting tool for educational and promotional programs. © 2011 Carvalho and Frazão-Moreira; licensee BioMed Central Ltd.


Booth A.E.G.,Imperial College London | Seabra M.C.,Imperial College London | Seabra M.C.,New University of Lisbon | Hume A.N.,University of Nottingham
Biochemical Society Transactions | Year: 2012

Rab proteins constitute the largest family within the Ras superfamily of small GTPases (>60 in mammals) and are essential regulators of transport between intracellular organelles. Key to this activity is their targeting to specific compartments within the cell. However, although great strides have been made over the last 25 years in assigning functions to individual Rabs and identifying their downstream effectors, the mechanism(s) regulating their targeting to specific subcellular membranes remains less well understood. In the present paper, we review the evidence supporting the proposed mechanisms of Rab targeting and highlight insights into this process provided by studies of Rab27a. ©The Authors Journal compilation ©2012 Biochemical Society.


Vicente L.N.,University of Coimbra | Custodio A.L.,New University of Lisbon
Mathematical Programming | Year: 2012

It is known that the Clarke generalized directional derivative is nonnegative along the limit directions generated by directional direct-search methods at a limit point of certain subsequences of unsuccessful iterates, if the function being minimized is Lipschitz continuous near the limit point. In this paper we generalize this result for discontinuous functions using Rockafellar generalized directional derivatives (upper subderivatives). We show that Rockafellar derivatives are also nonnegative along the limit directions of those subsequences of unsuccessful iterates when the function values converge to the function value at the limit point. This result is obtained assuming that the function is directionally Lipschitz with respect to the limit direction. It is also possible under appropriate conditions to establish more insightful results by showing that the sequence of points generated by these methods eventually approaches the limit point along the locally best branch or step function (when the number of steps is equal to two). The results of this paper are presented for constrained optimization and illustrated numerically. © 2010 Springer and Mathematical Optimization Society.


Vieira M.V.C.,New University of Lisbon
Optimization Methods and Software | Year: 2012

We present a generalization to symmetric optimization of interior-point methods for linear optimization based on kernel functions. Symmetric optimization covers the three most common conic optimization problems: linear, second-order cone and semi-definite optimization problems. Namely, we adapt the interior-point algorithm described in Peng et al. [Self-regularity: A New Paradigm for Primal-Dual Interior-point Algorithms. Princeton University Press, Princeton, NJ, 2002.] for linear optimization to symmetric optimization. The analysis is performed through Euclidean Jordan algebraic tools and a complexity bound is derived. © 2012 Copyright Taylor and Francis Group, LLC.


Cirio L.S.,University of Lisbon | Faria Martins J.,New University of Lisbon
Differential Geometry and its Application | Year: 2012

In the context of higher gauge theory, we construct a flat and fake flat 2-connection, in the configuration space of n particles in the complex plane, categorifying the Knizhnik-Zamolodchikov connection. To this end, we define the differential crossed module of horizontal 2-chord diagrams, categorifying the Lie algebra of horizontal chord diagrams in a set of n parallel copies of the interval. This therefore yields a categorification of the 4-term relation. We carefully discuss the representation theory of differential crossed modules in chain-complexes of vector spaces, which makes it possible to formulate the notion of an infinitesimal 2-R matrix in a differential crossed module. © 2012 Elsevier B.V.


Arada N.,New University of Lisbon
ESAIM - Control, Optimisation and Calculus of Variations | Year: 2013

The aim of this paper is to establish necessary optimality conditions for optimal control problems governed by steady, incompressible Navier-Stokes equations with shear-dependent viscosity. The main difficulty derives from the fact that equations of this type may exhibit non-uniqueness of weak solutions, and is overcome by introducing a family of approximate control problems governed by well posed generalized Stokes systems and by passing to the limit in the corresponding optimality conditions. © 2012 EDP Sciences, SMAI.


Da Fonseca J.B.,New University of Lisbon
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2015

In a previous work we showed that hardlimit multilayer neural networks have more computational power than sigmoidal multilayer neural networks [1]. In 1962 Minsky and Papert showed the limitations of a single perceptron which can only solve linearly separable classification problems and since at that time there was no algorithm to find the weights of a multilayer hardlimit perceptron research on neural networks stagnated until the early eighties with the invention of the Backpropagation algorithm [2]. Nevertheless since the sixties there have arisen some proposals of algorithms to implement logical functions with threshold elements or hardlimit neurons that could have been adapted to classification problems with multilayer hardlimit perceptrons and this way the stagnation of research on neural networks could have been avoided. Although the problem of training a hardlimit neural network is NP-Complete, our algorithm based on mathematical programming, a mixed integer linear model (MILP), takes few seconds to train the two input XOR function and a simple logical function of three variables with two minterms. Since any linearly separable logical function can be implemented by a perceptron with integer weights, varying them between -1 and 1 we found all the 10 possible solutions for the implementation of the two input XOR function and all the 14 and 18 possible solutions for the implementation of two logical functions of three variables, respectively, with a two layer architecture, with two neurons in the first layer. We describe our MILP model and show why it consumes a lot of computational resources, even a small hardlimit neural network translates into a MILP model greater than 1G, implying the use of a more powerful computer than a common 32 bits PC. We consider the reduction of computational resources as the near future work main objective to improve our novel MILP model and we will also try a nonlinear version of our algorithm based on a MINLP model that will consume less memory. © Springer International Publishing Switzerland 2015.


MacLaren R.E.,University of Oxford | MacLaren R.E.,Ophthalmology Biomedical Research Center | Groppe M.,University of Oxford | Groppe M.,Ophthalmology Biomedical Research Center | And 14 more authors.
The Lancet | Year: 2014

Background Choroideremia is an X-linked recessive disease that leads to blindness due to mutations in the CHM gene, which encodes the Rab escort protein 1 (REP1). We assessed the eff ects of retinal gene therapy with an adenoassociated viral (AAV) vector encoding REP1 (AAV.REP1) in patients with this disease. Methods In a multicentre clinical trial, six male patients (aged 35-63 years) with choroideremia were administered AAV.REP1 (0.6-1.0 × 1010 genome particles, subfoveal injection). Visual function tests included best corrected visual acuity, microperimetry, and retinal sensitivity tests for comparison of baseline values with 6 months after surgery. This study is registered with ClinicalTrials.gov, number NCT01461213. Findings Despite undergoing retinal detachment, which normally reduces vision, two patients with advanced choroideremia who had low baseline best corrected visual acuity gained 21 letters and 11 letters (more than two and four lines of vision). Four other patients with near normal best corrected visual acuity at baseline recovered to within one to three letters. Mean gain in visual acuity overall was 3.8 letters (SE 4.1). Maximal sensitivity measured with dark-adapted microperimetry increased in the treated eyes from 23.0 dB (SE 1.1) at baseline to 25.3 dB (1.3) after treatment (increase 2.3 dB [95% CI 0.8-3.8]). In all patients, over the 6 months, the increase in retinal sensitivity in the treated eyes (mean 1.7 [SE 1.0]) was correlated with the vector dose administered per mm-rfsti of surviving retina (r=0.82, p=0.04). By contrast, small non-signifi cant reductions (p<0.05) were noted in the control eyes in both maximal sensitivity (-0.8 dB [1.5]) and mean sensitivity (-1.6 dB [0.9]). One patient in whom the vector was not administered to the fovea re-established variable eccentric fi xation that included the ectopic island of surviving retinal pigment epithelium that had been exposed to vector. Interpretation The initial results of this retinal gene therapy trial are consistent with improved rod and cone function that overcome any negative eff ects of retinal detachment. These fi ndings lend support to further assessment of gene therapy in the treatment of choroideremia and other diseases, such as age-related macular degeneration, for which intervention should ideally be applied before the onset of retinal thinning.


Chaves M.,University of Lisbon | Chaves M.,New University of Lisbon | Davies B.,Lancaster University
Functional Plant Biology | Year: 2010

There is global concern over our capacity to feed a rapidly growing world population against a background of climate change and a shortage of renewable resources for agriculture. To address this challenge, sustainable intensification of crop production will be required to deliver increased yields with decreased environmental side effects, while maintaining the land area under cultivation. We must exploit new understanding in the science of crop production, in order to achieve both an improvement of crops and more effective agro-ecological management. The focus of this short article and the following papers that make up a research front on drought effects and water use efficiency is on science for the development of crops and cropping systems for water scarce environments. Both increases in drought resistance and efficiency of water use will be required in the major cropping regions of the world where water is already a significant limiting factor. © 2010 CSIRO.


Crucho C.I.C.,New University of Lisbon
ChemMedChem | Year: 2015

Nature continues to be the ultimate in nanotechnology, where polymeric nanometer-scale architectures play a central role in biological systems. Inspired by the way nature forms functional supramolecular assemblies, researchers are trying to make nanostructures and to incorporate these into macrostructures as nature does. Recent advances and progress in nanoscience have demonstrated the great potential that nanomaterials have for applications in healthcare. In the realm of drug delivery, nanomaterials have been used in vivo to protect the drug entity in the systemic circulation, ensuring reproducible absorption of bioactive molecules that do not naturally penetrate biological barriers, restricting drug access to specific target sites. Several building blocks have been used in the formulation of nanoparticles. Thus, stability, drug release, and targeting can be tailored by surface modification. Herein the state of the art of stimuli-responsive polymeric nanoparticles are reviewed. Such systems are able to control drug release by reacting to naturally occurring or external applied stimuli. Special attention is paid to the design and nanoparticle formulation of these so-called smart drug-delivery systems. Future strategies for further developments of a promising controlled drug delivery responsive system are also outlined. © 2015 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.


Ferreira da Silva A.R.,New University of Lisbon
Computer Methods and Programs in Biomedicine | Year: 2011

Bayesian approaches have been proposed by several functional magnetic resonance imaging (fMRI) researchers in order to overcome the fundamental limitations of the popular statistical parametric mapping method. However, the difficulties associated with subjective prior elicitation have prevented the widespread adoption of the Bayesian methodology by the neuroimaging community. In this paper, we present a Bayesian multilevel model for the analysis of brain fMRI data. The main idea is to consider that all the estimated group effects (fMRI activation patterns) are exchangeable. This means that all the collected voxel time series are considered manifestations of a few common underlying phenomena. In contradistinction to other Bayesian approaches, we think of the estimated activations as multivariate random draws from the same distribution without imposing specific prior spatial and/or temporal information for the interaction between voxels. Instead, a two-stage empirical Bayes prior approach is used to relate voxel regression equations through correlations between the regression coefficient vectors. The adaptive shrinkage properties of the Bayesian multilevel methodology are exploited to deal with spatial variations, and noise outliers. The characteristics of the proposed model are evaluated by considering its application to two real data sets. © 2010 Elsevier Ireland Ltd.


Rodrigues R.,New University of Lisbon
Computing in Cardiology | Year: 2010

When a set of medical signals has redundant information, it is sometimes possible to recover one signal, from its past and the information provided by the other signals. In this work, we present a general method to realize that task. It has been known for a long time that multilayered networks are universal approximators, but, even with the backprop algorithm, it was not possible to train such a network, to realize complex real life tasks. In the last years, Geoffrey Hinton presented a training strategy that allows to overcome the previous difficulties. We describe a way of adapting Hinton's strategy to our task. An example of a situation considered here, consists on training a Multilayered perceptron to take ECG leads II and I as input and produce as output missing lead V. This method got the best scores among participants in the Physionet/ Computing in Cardiology Challenge 2010.


Pages J.-M.,Jean Moulin University Lyon 3 | Amaral L.,New University of Lisbon | Fanning S.,University College Dublin
Current Medicinal Chemistry | Year: 2011

The worldwide dissemination of «multi-drug resistant» (MDR) pathogens has severely reduced the efficacy of our antibiotic arsenal and increased the frequency of therapeutic failure. MDR bacteria over-express efflux pumps and this active mechanism can extrude all classes of antibiotics from the cell. It is necessary to clearly decipher the genetic, structural and functional aspects of this transport system in order to combat this polyselective mechanism. By understanding how efflux pumps work we may be able to develop a new group of antibacterial agents, collectively termed efflux reversals, including membrane permeabilisers, efflux pump inhibitors and flux-competitive agents, specific blockers, energy poisons, etc. Several chemical families of efflux pump inhibitors have been described and characterized. Among them several inhibitor compounds demonstrate efficient blocking of the efflux pump activity involved in the MDR phenotype as observed in many Gram-negative clinical isolates. This new family of molecules represents the first antibacterial class of compound specifically targeting active transport in the bacterial cell. © 2011 Bentham Science Publishers Ltd.


Samagaio A.,University of Lisbon | Wolters M.,New University of Lisbon
Journal of Air Transport Management | Year: 2010

The study examines the official forecasts for airline passenger numbers for the Lisbon metropolitan area. Auto-regressive and exponential smoothing models are used to develop independent forecasts for passenger numbers. The forecasts show that the government forecasts are at the top end of estimates and should be considered overly optimistic. © 2009 Elsevier Ltd.


Wanke R.,New University of Lisbon
Organised Sound | Year: 2015

This article explores a particular perspective, shared across various contemporary musical currents, that focuses on sound itself as a complex entity. Through the analysis of certain fundamental musical elements and sonic characteristics, this study develops a new method for comparing different genres characterised by a similar approach to sound. Using the benefits of audio, spectra and score examinations, this strategy is applied to post-spectralist and minimalist compositions (e.g. G. F. Haas, B. Lang, R. Nova, G. Verrando), as well as glitch, electronic and basic-channel style pieces (Pan Sonic, R. Ikeda, Raime). Nine musical attributes are identified that help trace a new outlook on various currents in today's music. The study's contribution lies in its revealing of a shared musical perspective between different artistic practices, and in the establishment of new connections between pieces that belong to unrelated contexts. © Cambridge University Press 2015.


Santer R.,University of Hamburg | Calado J.,New University of Lisbon
Clinical Journal of the American Society of Nephrology | Year: 2010

Four members of two glucose transporter families, SGLT1, SGLT2, GLUT1, and GLUT2, are differentially expressed in the kidney, and three of them have been shown to be necessary for normal glucose resorption from the glomerular filtrate. Mutations in SGLT1 are associated with glucose-galactose malabsorption, SGLT2 with familial renal glucosuria (FRG), and GLUT2 with Fanconi-Bickel syndrome. Patients with FRG have decreased renal tubular resorption of glucose from the urine in the absence of hyperglycemia and any other signs of tubular dysfunction. Glucosuria in these patients can range from <1 to >150 g/1.73 m2 per d. The majority of patients do not seem to develop significant clinical problems over time, and further description of specific disease sequelae in these individuals is reviewed. SGLT2, a critical transporter in tubular glucose resorption, is located in the S1 segment of the proximal tubule, and, as such, recent attention has been given to SGLT2 inhibitors and their utility in patients with type 2 diabetes, who might benefit from the glucose-lowering effect of such compounds. A natural analogy is made of SGLT2 inhibition to observations with inactivating mutations of SGLT2 in patients with FRG, the hereditary condition that results in benign glucosuria. This review provides an overview of renal glucose transport physiology, FRG and its clinical course, and the potential of SGLT2 inhibition as a therapeutic target in type 2 diabetes. Copyright © 2010 by the American Society of Nephrology.


Freitas A.A.,University of Lisbon | Shimizu K.,University of Lisbon | Canongia Lopes J.N.,University of Lisbon | Canongia Lopes J.N.,New University of Lisbon
Journal of Chemical and Engineering Data | Year: 2014

This article shows that the diverse structure and morphology of different ionic liquids can be interpreted using structure factor and radial distribution data. These two functions can be obtained using molecular dynamics (MD) simulation techniques. The lowest-q peaks of the structure factor spectra (prepeaks) can be assigned to characteristic separations between strands of the ionic liquid polar network that are mediated by nonpolar regions. On the other hand, the second lowest q-peaks reflect the medium-range ordering of the polar network itself. The systematic comparison between different groups of ionic liquids allows us to rationalize the relative amplitude and position of those peaks with the underlying structure of the ionic liquid and interpret such an outcome in terms of the relative size and nature of the corresponding ions. © 2014 American Chemical Society.


Paoletti I.,New University of Lisbon | Gomes S.,ISPA University
Journal of Aging Studies | Year: 2014

This article focuses on the relevance that the dimension of the future has for promoting healthy and active aging. Older people generally have difficulties in talking about the future and when they do they generally express very negative perspectives on it. The data analyzed in this paper are part of an on-going interdisciplinary research project: "Aging, poverty and social exclusion: an interdisciplinary study on innovative support services" (https://apseclunl.wordpress.com/). The project aims at documenting good practices in social intervention with older people who are at risk of exclusion. This study describes and critically discusses an activity carried out in Portugal among older women in a poor area in the suburb of Lisbon entitled "self-awareness workshop on the future". Through a detailed discourse analysis within an ethnomethodological framework the study shows age membership categorizations in use and categorization processes, examining the workshop interaction. In particular, the article describes how the psychologist works at deconstructing and problematizing the negative connotations related to age membership categories. Taking into consideration the interactionally constructed nature of aging and the material consequences that different attitudes towards aging can imply is very important in particular in relation to the provision of services to older people. © 2014 Elsevier Inc.


Faria Martins J.,New University of Lisbon
Journal of Geometry and Physics | Year: 2016

After a thorough treatment of all algebraic structures involved, we address two dimensional holonomy operators with values in crossed modules of Hopf algebras and in crossed modules of associative algebras (called here crossed modules of bare algebras). In particular, we will consider two general formulations of the two-dimensional holonomy of a (fully primitive) Hopf 2-connection (exact and blur), the first being multiplicative the second being additive, proving that they coincide in a certain natural quotient (defining what we called the fuzzy holonomy of a fully primitive Hopf 2-connection). © 2015 Elsevier B.V.


Yeasts are common inhabitants of different types of aquatic habitats, including marine and estuarine waters and rivers. Although numerous studies have surveyed yeast occurrence in these habitats, the identification of autochthonous populations has been problematic because several yeast species seem to be very versatile and therefore mere presence is not sufficient to establish an ecological association. In the present study we investigated the dynamics of the yeast community in the Tagus river estuary (Portugal) by combining a microbiological study involving isolation, quantification, and molecular identification of dominant yeast populations with the analysis of hydrological and hydrographical data. We set out to test the hypothesis of the multiple origins of estuarine yeast populations in a transect of the Tagus estuary and we postulate four possible sources: open sea, terrestrial, gastrointestinal and the estuary itself in the case of populations that have become resident. Candida parapsilosis and Pichia guilliermondii were correlated with Escherichia coli, which indicated an intestinal origin. Other cream-colored yeasts like Debaryomyces hansenii and Candida zeylanoides had similar dynamics, but no association with E. coli and quite distinct ecological preferences. They might represent a group of resident estuarine populations whose primary origin is diverse and can include marine, terrestrial, and gastrointestinal habitats. Another major yeast population was represented by Rhodotorula mucilaginosa. The cosmopolitan nature of that species and its moderate association with E. coli point to terrestrial sources as primary habitats.


Chalub F.A.C.C.,New University of Lisbon | Souza M.O.,Federal University of Fluminense
Mathematical and Computer Modelling | Year: 2011

We present a derivation of the classical Susceptible-Infected-Removed (SIR) and Susceptible-Infected-Removed-Susceptible (SIRS) models through a mean-field approximation from a discrete version of SIR(S). We then obtain a hyperbolic forward Kolmogorov equation, and show that its projected characteristics recover the standard SIR(S) model. Moreover, for the SIRS model, we show that the long time limit of the SIRS model will be a Dirac measure supported on the corresponding isolated equilibria. For the SIR model, we show that the long time limit is a Radon measure supported in a segment of nonisolated equilibria. © 2010 Elsevier Ltd.


Fernandes H.L.,Northwestern University | Fernandes H.L.,New University of Lisbon | Albert M.V.,Northwestern University | Kording K.P.,Northwestern University
PLoS ONE | Year: 2011

Recent studies in motor control have shown that visuomotor rotations for reaching have narrow generalization functions: what we learn during movements in one direction only affects subsequent movements into close directions. Here we wanted to measure the generalization functions for wrist movement. To do so we had 7 subjects performing an experiment holding a mobile phone in their dominant hand. The mobile phone's built in acceleration sensor provided a convenient way to measure wrist movements and to run the behavioral protocol. Subjects moved a cursor on the screen by tilting the phone. Movements on the screen toward the training target were rotated and we then measured how learning of the rotation in the training direction affected subsequent movements in other directions. We find that generalization is local and similar to generalization patterns of visuomotor rotation for reaching. © 2011 Fernandes et al.


Pereira D.,University of Porto | Peleteiro B.,University of Porto | Araujo J.,University of Porto | Branco J.,New University of Lisbon | And 2 more authors.
Osteoarthritis and Cartilage | Year: 2011

Objective: To understand the differences in prevalence and incidence estimates of osteoarthritis (OA), according to case definition, in knee, hip and hand joints. Method: A systematic review was carried out in PUBMED and SCOPUS databases comprising the date of publication period from January 1995 to February 2011. We attempted to summarise data on the incidence and prevalence of OA according to different methods of assessment: self-reported, radiographic and symptomatic OA (clinical plus radiographic). Prevalence estimates were combined through meta-analysis and between-study heterogeneity was quantified. Results: Seventy-two papers were reviewed (nine on incidence and 63 on prevalence). Higher OA prevalences are seen when radiographic OA definition was used for all age groups. Prevalence meta-analysis showed high heterogeneity between studies even in each specific joint and using the same OA definition. Although the knee is the most studied joint, the highest OA prevalence estimates were found in hand joints. OA of the knee tends to be more prevalent in women than in men independently of the OA definition used, but no gender differences were found in hip and hand OA. Insufficient data for incidence studies didn't allow us to make any comparison according to joint site or OA definition. Conclusions: Radiographic case definition of OA presented the highest prevalences. Within each joint site, self-reported and symptomatic OA definitions appear to present similar estimates. The high heterogeneity found in the studies limited further conclusions. © 2011 Osteoarthritis Research Society International.


Hartskeerl R.A.,OIE and National Leptospirosis Reference Center | Collares-Pereira M.,New University of Lisbon | Ellis W.A.,AFBI Veterinary Research Laboratories
Clinical Microbiology and Infection | Year: 2011

Globally, leptospirosis poses an increasing public health problem, as evidenced by markedly increasing incidence rates and multiple outbreaks in all continents. Yet, the disease is severely neglected and hence, its global burden is largely unknown. The estimated incidence of about half a million severe human cases annually is probably an underestimation while the burden for animal health is unknown. It is anticipated that current international initiatives will assess the global burden of leptospirosis, while mathematical modelling of transmission dynamics will allow the identification and testing of appropriate intervention and outbreak response measures within the coming years. © 2011 The Authors. Clinical Microbiology and Infection © 2011 European Society of Clinical Microbiology and Infectious Diseases.


Goncalves R.,New University of Lisbon | Camotim D.,University of Lisbon
Thin-Walled Structures | Year: 2013

In a recent paper (Gonçalves and Camotim, 2013 [1]), the authors presented an investigation concerning the buckling (bifurcation) behaviour of uniformly compressed thin-walled tubes with regular polygonal cross-sections (RCPS). The present paper complements the previous work by addressing the local and distortional buckling behaviour of RCPS members subjected to bending or torsion and aims at providing a novel insight into these phenomena. In particular, the specialization of Generalized Beam Theory (GBT) for RCPS, as recently proposed in Gonçalves and Camotim (2013) [2], is employed to obtain closed-form analytical solutions and also to carry out parametric studies by means of numerical analyses which are both computationally efficient (due to the small number of d.o.f. involved) and clarifying (due to the modal decomposition features of GBT). For validation purposes, solutions taken from the literature and also standard shell finite element model results are employed. © 2013 Elsevier Ltd.


Goncalves R.,New University of Lisbon | Camotim D.,University of Lisbon
Thin-Walled Structures | Year: 2013

This paper investigates the elastic buckling (bifurcation) behaviour of uniformly compressed thin-walled tubular members with single-cell regular polygonal cross-sections (RCPS), such as those employed to build transmission line structures, towers, antennas and masts. A specialisation of Generalised Beam Theory (GBT) for RCPS, reported in a recent paper (Gonçalves and Camotim, 2013) [1], is used to obtain both analytical and numerical results concerning the most relevant buckling modes and provide novel and broad conclusions on the structural behaviour of this type of members. In particular, local, cross-section extensional, distortional and multi-mode (including global flexural) buckling phenomena are addressed. For validation purposes, the GBT-based results are compared with solutions taken from the literature and also with numerical values obtained from finite strip analyses. © 2013 Elsevier Ltd.


Marques M.,Institute Desenvolvimento Of Novas Tecnologias | Neves-Silva R.,New University of Lisbon
Journal of Cleaner Production | Year: 2015

LifeSaver project congregates the development of contextualized decision support approach for energy savings and emissions trading. This approach aims at supporting industrial users in selecting the best alternative to ensure minimization of energy consumption during the production process as well as support to emissions trading market. LifeSaver provides decision support for: (i) immediate reaction and (ii) process reconfiguration and Emission Trading System. This categorization serves as base for defining the methods to be applied. The support for immediate reaction uses Case-based Reasoning together with probabilistic analysis. Process reconfiguration and ETS is implemented through the use of multi-criteria decision analysis based on MACBETH method, which has been adapted for LifeSaver specific characteristics. The paper proposes categorization of approaches, main criteria involved in the process and associated algorithms. Moreover the approaches proposed were successfully tested in industrial environment and the results obtained are here presented. © 2014 Elsevier Ltd. All rights reserved.


Peleja F.,New University of Lisbon
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2015

It is common for a celebrity, brand, or movie to become a reference in the domain and to be vastly cited as an example of a highly reputable entity. Popmeter1 is a search/browsing application to visualize the reputation of an entity and its corresponding sentiment connections (in hate-it or love-it manner). Popmeter is supported by a sentiment graph populated by named-entities and sentiment words. The sentiment graph is constructed by a reputation analysis procedure that models the sentiment of each sentence where the entity is mentioned. This analysis leverages on a sentiment lexicon that includes general sentiment words that characterize the general sentiment towards the targeted named-entity. © Springer International Publishing Switzerland 2015.


Povoa P.,Polyvalent Intensive Care Unit | Povoa P.,New University of Lisbon | Teixeira-Pinto A.M.,University of Porto | Carneiro A.H.,Abel Salazar Biomedical Sciences Institute
Critical Care | Year: 2011

Introduction: C-reactive protein (CRP) has been shown to be a valuable marker in the diagnosis of infection and in monitoring its response to antibiotics. Our objective was to evaluate serial CRP measurements after prescription of antibiotics to describe the clinical course of Community-Acquired Sepsis admitted to intensive care units (ICU).Methods: During a 12-month period a multi-center, prospective, observational study was conducted, segregating adults with Community-Acquired Sepsis. Patients were followed-up during the first five ICU days, day of ICU discharge or death and hospital outcome. CRP-ratio was calculated in relation to Day 1 CRP concentration. Patients were classified according to the pattern of CRP-ratio response to antibiotics: fast response if Day 5 CRP-ratio was < 0.4, slow response if Day 5 CRP-ratio was between 0.4 and 0.8, and no response if Day 5 CRP-ratio was > 0.8. Comparison between survivors and non-survivors was performed.Results: A total of 891 patients (age 60 ± 17 yrs, hospital mortality 38%) were studied. There were no significant differences between the CRP of survivors and non-survivors until Day 2 of antibiotic therapy. On the following three days, CRP of survivors was significantly lower (P < 0.001). After adjusting for the Simplified Acute Physiology Score II and severity of sepsis, the CRP course was significantly associated with mortality (ORCRP-ratio= 1.03, confidence interval 95%= (1.02, 1.04), P < 0.001). The hospital mortality of patients with fast response, slow response and no response patterns was 23%, 30% and 41%, respectively (P = 0.001). No responders had a significant increase on the odds of death (OR = 2.5, CI95%= (1.6, 4.0), P < 0.001) when compared with fast responders.Conclusions: Daily CRP measurements after antibiotic prescription were useful as early as Day 3 in identification of Community-Acquired Sepsis patients with poor outcome. The rate of CRP decline during the first five ICU days was markedly associated with prognosis. The identification of the pattern of CRP-ratio response was useful in the recognition of the individual clinical course. © 2011 Póvoa et al.; licensee BioMed Central Ltd.


Guerra T.,Polytechnic Institute of Setubal | Guerra T.,New University of Lisbon
Journal of Mathematical Fluid Mechanics | Year: 2012

We consider optimal control problems of systems governed by quasi-linear, stationary, incompressible Navier- Stokes equations with shear-dependent viscosity in a two-dimensional or three-dimensional domain. We study a general class of viscosity functions with shear-thinning behaviour. Our aim is to prove the existence of a solution for the class of control problems and derive the first order optimality conditions. © 2012 Springer Basel AG.


Martins M.,New University of Lisbon
Methods in molecular biology (Clifton, N.J.) | Year: 2010

Two simple, instrument-free, user-friendly methods that can readily be implemented by a routine microbiology laboratory are described for the detection of multi-drug-resistant (MDR) isolates that overexpress efflux pump (EP) systems responsible for the MDR phenotype. The first method employs the universal EP substrate ethidium bromide (EB) at varying concentrations in agar-containing plates upon which the contents of an overnight culture are swabbed as spokes of a wheel. In this method, named the EB-agar cartwheel method, it is assumed that the smallest concentration of EB that produces fluorescence of the bacterial mass represents the highest concentration of EB that the bacteria can exclude. Consequently, as the efflux system(s) of a given MDR clinical bacterial isolate is overexpressed relative to that of a reference strain, the minimal concentration of EB producing fluorescence is significantly greater. A simple formula is provided which affords the ranking of MDR clinical isolates with respect to the degree of their efflux capacity. The second method, which can be used after the first one, determines whether the MDR phenotype is based upon an overexpressed efflux system. This method employs a 24-well microplate with separate wells containing or lacking an efflux pump inhibitor (EPI) and Kirby-Bauer discs that correspond to the antibiotics to which the MDR strain is resistant. After the wells are inoculated with the MDR clinical isolate, the plate is incubated overnight and each well is evaluated by eye for evidence of growth. Comparison of growth to the relevant control enables the observer to determine the following outcomes: no growth produced by the EPI-antibiotic combination (i.e., reversal of antibiotic resistance); reduced growth produced by the EPI-antibiotic combination; no difference in growth, i.e., EPI does not affect the resistance to the given antibiotic. If the first method showed that there was a significant difference between the minimum concentrations of EB in agar that produced fluorescence for the clinical isolate and its reference strain, then one can conclude that if the EPI had no effect on reducing antibiotic resistance, the differences in the EB concentrations that produced fluorescence are probably due to differences in the permeability of the strain to EB, reflecting a downregulation of porins if the clinical isolate is a Gram-negative bacterium.


Leitao J.,New University of Lisbon
Proceedings of the 2nd Workshop on the Principles and Practice of Consistency for Distributed Data, PaPoC 2016 | Year: 2016

Replication is a key technique for providing both fault tolerance and availability in distributed systems. However, managing replicated state, and ensuring that these replicas remain consistent, is a non trivial task, in particular in scenarios where replicas can reside on the client-side, as clients might have unreliable communication channels and hence, exhibit highly dynamic communication patterns. One way to simplify this task is to resort to CRDTs, which are data types that enable replication and operation over replicas with no coordination, ensuring eventual state convergence when these replicas are synchronized. However, when the communication patters, and therefore synchronization patterns, are highly dynamic, existing designs of CRDTs might incur in excessive communication overhead. To address those scenarios, in this paper we propose a new design for CRDTs which we call Δ-CRDT, and experimentally show that under dynamic communication patters, this novel design achieves better network utilization than existing alternatives. © 2016 ACM.


Muralha V.S.F.,University College London | Muralha V.S.F.,New University of Lisbon | Burgio L.,University College London | Clark R.J.H.,University College London
Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy | Year: 2012

The palette of four Persian manuscripts of the 16th and 17th centuries were established by Raman microscopy to include lazurite, red lead, vermilion, orpiment, a carbon-based black, lead white, malachite, haematite, indigo, carmine and pararealgar. The first five pigments were identified on all four manuscripts, as previously found for other Islamic manuscripts of this period. The findings were compared with information available in treatises on Persian painting techniques. Red lead, although identified on all of the manuscripts analysed in this study as the main red pigment, is seldom mentioned in the literature. Two unusual pigments were also identified: the intermediate phase between realgar and pararealgar in the manuscript Timur namah, and carmine in the manuscript Shah namah. Although the established palette comprises few pigments, it was found that the illuminations were enhanced by the use of pigment mixtures, the components of which could be identified by Raman microscopy. © 2012 Elsevier B.V. All rights reserved.


de Almeida J.A.,New University of Lisbon
Earth-Science Reviews | Year: 2010

The construction of a reservoir model begins with the geology, specifically a geological conceptual model, sub-division into layers, top and bottom limits/surfaces, and characterization of rock types or facies within the layers. To model the geology in heterogeneous case studies, of which carbonate reservoirs are a good example, conceptual and deterministic models are unable to adequately represent the internal geometry and, for this reason, stochastic models are most, particularly used mainly for the spatial characterization of rock types.This paper presents a comparison of bi-point geostatistical simulation methods for characterization of lithoclasses, making use of a carbonated reservoir as a case study. To cope with the geological complexity, and to assist in understanding the internal distribution of properties, the lithoclasses were derived from cores based on their lithology, petrophysical properties and capillary pressure, and subsequently extended to log data.Five simulation methodologies, able to deal with categorical variables, are compared in a multi-phase framework: (1) truncated gaussian simulation, posterior conditioning and classification of simulated probabilities based on local and global proportions (TGSPC); (2) truncated gaussian simulation, posterior conditioning and classification using simulated annealing (TGSPC. +. SA); (3) sequential indicator simulation with correction for local probabilities (SIS); (4) simulated annealing post-processing of sequential indicator simulation images (SIS. +. SA); and (5) probability field simulation (PFS). Matched to experimental data, theoretical multi-phase variogram models, and proportions are observed, as well as the presence of artefacts. To evaluate the range of uncertainty of the simulated images, 30 realizations are generated, and entropy and average geobody volumes (connected blocks belonging to the same lithoclass) are computed and compared. © 2010 Elsevier B.V.


Perelman J.,New University of Lisbon
Economics and Human Biology | Year: 2014

This paper analyze the association between height and chronic diseases in Portugal and the extent to which this relationship is mediated by education. The sample upon which the analysis is based comprised those participants in the 2005/2006 Portuguese National Health Interview Survey (n = 28,433) aged 25-79. Logistic regressions measured the association of height with ten chronic diseases, adjusting for age, lifestyle, education, and other socioeconomic factors. Among women, an additional centimeter in stature significantly decreased the prevalence of asthma, chronic pain, and acute cardiac disease, by 0.057, 0.221, and 0.033 percentage points, respectively. Also, mental disorders were significantly less prevalent in the last quartile of height. Among men, an additional centimeter in height was associated with a 0.074 lower prevalence of asthma, and men in the last quartile of height were significantly less at risk of acute cardiovascular disease. There was no significant association between height and the risk of diabetes, high blood pressure, cancer, and pulmonary diseases. As for the impact of education, women with a tertiary level were on average 5.3 cm taller than those with no schooling; among men, the difference was almost 9 cm. Adjusting for education reduced the height-related excess risk of ill health by 36% on average among men, and by 7% among women. The analysis indicates that there is a significant association of height with several chronic conditions, and that education plays a mediating role in the height-health connection. By emphasizing the role of height and education as determinants of chronic conditions, this paper also highlights the role of conditions related to childhood health and socioeconomic background. ©2014 Elsevier B.V. All rights reserved.


Estudante M.,University of Lisbon | Estudante M.,University of California at San Francisco | Morais J.G.,University of Lisbon | Soveral G.,New University of Lisbon | And 2 more authors.
Advanced Drug Delivery Reviews | Year: 2013

The importance of drug transporters as one of the determinants of pharmacokinetics has become increasingly evident [1]. While much research has been conducted focusing the role of drug transporters in the liver [2-5] and kidney [2,6,7] less is known about the importance of uptake and efflux transporters identified in the intestine [8]. Over the past years the effects of intestinal transporters have been studied using in vivo models, in situ organ perfusions, in vitro tissue preparations and cell lines. This review aims to describe up to date findings regarding the importance of intestinal transporters on drug absorption and bioavailability, highlighting areas in need of further research. Wu and Benet [9] proposed a Biopharmaceutics Drug Disposition Classification System (BDDCS) that allows the prediction of transporter effects on the drug disposition of orally administered drugs. This review also discusses BDDCS predictions with respect to the role of intestinal transporters and intestinal transporter-metabolizing enzyme interplay on oral drug pharmacokinetics. © 2012 Elsevier B.V.


Dias C.J.,New University of Lisbon
International Journal of Heat and Mass Transfer | Year: 2015

Abstract An innovative method of recursive images is presented to obtain solutions to the transient diffusion equation in a N-layered material based on the superposition of Green functions for a semi-infinite material. Through a sequential sum of image reflected functions a temperature solution is initially built for a structure of one layer over a substrate. These functions are chosen in order to satisfy in sequence the boundary conditions, first at the front interface then at the back interface then again at the front interface and so on until the magnitude of the added functions becomes negligible. Based on this so-called 1-layer algorithm, a 2-layer algorithm is obtained. This is accomplished through a sequential application of the 1-layer algorithm first to layer 1 then to layer 2 then again to layer 1 and so on. After that it is suggested how the sequential application of the N - 1 algorithm leads to the N-layer algorithm. This present scheme is valid for boundary conditions of the first and second kind but it will not applicable neither to the case where there is a contact resistance between layers or to the case of convective heat transfer at the end interfaces. © 2015 The Author.


Dias C.J.,New University of Lisbon
International Journal of Heat and Mass Transfer | Year: 2015

Abstract A method of recursive images applicable to diffusion in multilayer materials, is extended to cases where there is convection at the outer faces. Therefore this old/new method is now applicable to a wider, more diverse and real life diffusion problems. This objective is reached using a result by Bryan [1] who established that the Green function at a convection boundary involves adding a mirror reflecting thermal wave while subtracting a one-sided convolution, of a decreasing exponential with that same reflected wave. This is verified in the case of convection of heat, for a slab with its back face insulated. This method was then applied to find temperature solution for the diffusion in a slab having convection both at the front and at the back face of the slab. Finally the same rationale, of the recently proposed method of generalized method of images, was used to find the temperature solution for a three layered material with radiation convection at its front face. An alternative method is suggested which minimizes computation errors when the convection coefficient becomes very large. Finally a relationship is found between the semi-infinite solutions with and without convection radiation. © 2014 Elsevier Ltd. All rights reserved.


Guedes A.C.,University of Porto | Amaro H.M.,University of Porto | Malcata F.X.,Superior Institute of Maia | Malcata F.X.,New University of Lisbon
Marine Drugs | Year: 2011

Marine microalgae constitute a natural source of a variety of drugs for pharmaceutical, food and cosmetic applications-which encompass carotenoids, among others. A growing body of experimental evidence has confirmed that these compounds can play important roles in prevention (and even treatment) of human diseases and health conditions, e.g., cancer, cardiovascular problems, atherosclerosis, rheumatoid arthritis, muscular dystrophy, cataracts and some neurological disorders. The underlying features that may account for such favorable biological activities are their intrinsic antioxidant, anti-inflammatory and antitumoral features. In this invited review, the most important issues regarding synthesis of carotenoids by microalgae are described and discussed-from both physiological and processing points of view. Current gaps of knowledge, as well as technological opportunities in the near future relating to this growing field of interest, are also put forward in a critical manner. © 2011 by the authors; licensee MDPI.


Martins V.N.,University of The Azores | e Silva D.S.,Nucleo Of Ecologia Social Do Laboratorio Nacional Of Engineering Civil | Cabral P.,New University of Lisbon
Natural Hazards | Year: 2012

The increase in the frequency and magnitude of disasters triggered by earthquakes in different regions of the Earth is a major challenge to contemporary societies. The awareness that disasters and risk are processes structured on spatial-temporal interactions maintained at the social-ecological system between the natural hazards and the vulnerabilities of socioeconomic, political and physical nature becomes utterly important in the increase of social systems' resilience. Thus, the assessment of social vulnerability plays a decisive role in understanding the factors that distinguishes individuals, households and communities, in terms of their ability to anticipate, cope with, resist to and recover from the impact of disasters triggered by natural hazards. This article presents a geographic information system (GIS)-based approach model to assess the social vulnerability to seismic risk using multicriteria analysis (MCA) techniques, in a group decision-making process. The methodology applied to the municipality of Vila Franca do Campo (São Miguel Island, Azores, Portugal) identified moderate social vulnerability values at the neighbourhood level and higher social vulnerability values for the built environment and demographic characteristics of the social groups. The social vulnerability patterns make a clear distinction between the older/historical urban cores and the new urban areas. In the first case, the presence of ancient buildings constructed with materials of low resistance to earthquakes coupled with a higher population density and the traits of demographic and socioeconomic frailties of the social groups, results in higher vulnerability values. This pattern is common in the historic centre of S. Miguel district, Ribeira das Taínhas, northern areas of Água de Alto and western and eastern neighbourhoods of Ponta Garça. The new urban areas, mainly found in S. Pedro, central areas of Água de Alto, S. Miguel and Ponta Garça districts, have lower values of social vulnerability due to changes in the built, demographic and socioeconomic environments. Results recommend the integration of social vulnerability indexes into seismic risk mitigation policies and emergency management planning. © 2012 Springer Science+Business Media B.V.


Gandra J.,University of Lisbon | Miranda R.M.,New University of Lisbon | Vilaca P.,University of Lisbon
Journal of Materials Processing Technology | Year: 2012

Performance criteria regarding the material deposition rate and energy consumption per unit of deposited mass were established for the characterization of friction surfacing. These criteria were tested in the friction surfacing of mild steel, for a range of process parameters. The influence of forging force, consumable tilt angle, travel and rotation speeds on interfacial bond properties and process efficiency were investigated. Coatings were examined by optical microscopy, image processing techniques and hardness testing. The applied load on the consumable rod was found to be essential to improve joining efficiency and to increase the deposition rate. Higher rotation or travel speeds were detrimental for the joining efficiency. Tilting the consumable rod along the travel direction proved to improve the joining efficiency up to 5%. For the testing conditions under study, the material loss in flashes represented about 40-60% of the total rod consumed, while unbonded regions were reduced to 8% of the effective coating section. Friction surfacing was seen to require mechanical work between 2.5 and 5 kJ/g of deposited coating with deposition rates of 0.5-1.6 g/s. Deposition rates are higher than for laser cladding or plasma arc welding with a specific energy consumption lower than for other cladding processes. © 2012 Elsevier B.V. All rights reserved.


BACKGROUND: This study aimed to determine factors associated with body composition changes shortly after liver transplantation (LTx), including the influence of immunosuppressive agents. The combined resting energy expenditure (REE) and handgrip strength provided a valuable assessment in data interpretation of body composition. METHODS: This observational single-center study included a cohort of consecutive end-stage liver disease patients with indications for LTx over 2 years. Cyclosporine was preferred for diabetic, hepatitis C–infected, and human immunodeficiency virus–infected patients per the transplant center protocol. Subjective Global Assessment, handgrip strength, multifrequency bioelectrical impedance analysis, and REE measurements were collected. The assessments were performed before LTx (T0) and at medians of 9 (T1) and 36 (T2) days after LTx. The fat mass index (FMI) and lean mass index (LMI) were surrogates of adiposity and skeletal muscle, respectively. Multiple linear regression analysis was used. RESULTS: Fifty-six patients with a mean age of 53.7 (8.5) years were included; 87.5% were men. Preoperative Subjective Global Assessment undernourishment (β-estimate = 17.9; P = 0.004) and of drug addiction absence (β estimate = 14.6; P = 0.049) were associated with FMI increase. Higher REE at T1 (per 100 kcal) was associated with LMI increase (β estimate = 1.70; P = 0.012) and body cell mass increase (β estimate = 1.60; P = 0.049). The cyclosporine-based regimen was associated with FMI decrease (β estimate = −25.64; P < 0.001) and LMI increase (β estimate = 23.76; P < 0.001) when compared with a tacrolimus-based regimen. Steroids did not affect body composition. CONCLUSIONS: The cyclosporine-based regimen was independently associated with decreased adiposity and increased skeletal muscle compared with the tacrolimus-based regimen. Future randomized controlled trials are needed to confirm these findings. Copyright © 2016 Wolters Kluwer Health, Inc. All rights reserved.


Carney R.P.,Ecole Polytechnique Federale de Lausanne | Astier Y.,New University of Lisbon | Astier Y.,IBM | Carney T.M.,Ecole Polytechnique Federale de Lausanne | And 3 more authors.
ACS Nano | Year: 2013

Understanding as well as rapidly screening the interaction of nanoparticles with cell membranes is of central importance for biological applications such as drug and gene delivery. Recently, we have shown that "striped" mixed-monolayer-coated gold nanoparticles spontaneously penetrate a variety of cell membranes through a passive pathway. Here, we report an electrical approach to screen and readily quantify the interaction between nanoparticles and bilayer lipid membranes. Membrane adsorption is monitored through the capacitive increase of suspended planar lipid membranes upon fusion with nanoparticles. We adopt a Langmuir isotherm model to characterize the adsorption of nanoparticles by bilayer lipid membranes and extract the partition coefficient, K, and the standard free energy gain by this spontaneous process, for a variety of sizes of cell-membrane-penetrating nanoparticles. We believe that the method presented here will be a useful qualitative and quantitative tool to determine nanoparticle interaction with lipid bilayers and consequently with cell membranes. © 2012 American Chemical Society.


Noronha P.,New University of Lisbon
Leonardo | Year: 2016

The author explores the use of tridimensional filamentous fungi patterns to produce biopaintings. The painting process involves incorporation of food dyes into a fungi growth medium. Then, after some biochemical processes, the fungal forms are dehydrated and immobilized in polyester resin. Changes in colors and texture occur, resulting in lively images. © 2016 ISAST.


Martins N.F.M.,New University of Lisbon
Inverse Problems | Year: 2015

We establish identification results in an inverse source problem for the two-dimensional Brinkman equations. This identification problem is cast in the context of a nondestructive evaluation problem that consists in retrieving a pair of forces, namely a body force and a divergence force, from the corresponding Cauchy data. Results are established for data obtained from a single measurement and from several measurements. Extension to three-dimensional problems is also discussed. © 2015 IOP Publishing Ltd.


Advances recently introduced into the Clinical Mycobacteriology Laboratory of the Institute of Hygiene and Tropical Medicine, such that a multi-drug resistant infection of pulmonary tuberculosis (MDR TB) can be identified within one day of receiving the sputum specimen, have greatly contributed to the reduction of the frequency of these infections. However, approximately 50% of reduced infections exhibit a phenotype that is consistent with that presented by an extensively drug-resistant (XDR) infection. More effective agents were required and hence attention was attributed to the possibility that the old neuroleptic phenothiazine thioridazine (TZ), previously shown to inhibit the growth of all encountered strains of Mycobacterium tuberculosis (Mtb) regardless of their antibiotic resistance profile, could be eventually used for therapy of problematic MDR/XDR TB infections. This mini-review discusses the mechanisms that render TZ an effective adjuvant to antibiotics to which the initial infective agent Mtb was resistant.


Correia I.,New University of Lisbon | Nickel S.,Karlsruhe Institute of Technology | Nickel S.,Fraunhofer Institute for Industrial Mathematics | Saldanha-da-Gama F.,University of Lisbon
Networks and Spatial Economics | Year: 2014

In this paper we extend the classical capacitated single-allocation hub location problem by considering that multiple products are to be shipped through the network. We propose a unified modeling framework for the situation in which no more than one hub can be located in each node. In particular, we consider the case in which all hubs are dedicated to handling a single-product as well as the case in which all hubs can handle all products. The objective is to minimize the total cost, which includes setup costs for the hubs, setup costs for each product in each hub and flow routing costs. Hubs are assumed to be capacitated. For this problem several models are proposed which are based on existing formulations for the (single-product) capacitated single-allocation hub location problem. Additionally, several classes of inequalities are proposed in order to strengthen the models in terms of the lower bound provided by the linear relaxation. We report results of a set of computational experiments conducted to test the proposed models and their enhancements. © 2013 Springer Science+Business Media New York.


dos Santos F.A.,New University of Lisbon
Journal of Engineering Mechanics | Year: 2016

This paper studies innovative restraining solutions based on lateral nickel-titanium (NiTi) shape-memory alloy (SMA) cables. Two novel control approaches are tested, which take advantage of superelasticity and the shape-memory effect. Superelasticity is employed in a passive control approach, using the restraining cables to increase the postbuckling resistance and recentering capabilities of a compressed column while dissipating energy. A numerical model to simulate this passive control system is also proposed and validated, adequately representing both its material and geometric nonlinearities. Additional parametric tests are performed, providing more insight into the good performance of the proposed system. The shape-memory effect (SME) is used in an active control approach, using the cables as actuators to counteract the buckling motion of the column. Experimental prototypes are built and tested in order to investigate the feasibility and effectiveness of these two control solutions, which aim to demonstrate the versatility of these exceptional materials for new structural applications. © 2016 American Society of Civil Engineers.


Freire S.,New University of Lisbon | Aubrecht C.,AIT Austrian Institute of Technology
Natural Hazards and Earth System Science | Year: 2012

Disaster risk is not fully characterized without taking into account vulnerability and population exposure. Assessment of earthquake risk in urban areas would benefit from considering the variation of population distribution at more detailed spatial and temporal scales, and from a more explicit integration of this improved demographic data with existing seismic hazard maps. In the present work, "intelligent" dasymetric mapping is used to model population dynamics at high spatial resolution in order to benefit the analysis of spatio-temporal exposure to earthquake hazard in a metropolitan area. These night-and daytime-specific population densities are then classified and combined with seismic intensity levels to derive new spatially-explicit four-class-composite maps of human exposure. The presented approach enables a more thorough assessment of population exposure to earthquake hazard. Results show that there are significantly more people potentially at risk in the daytime period, demonstrating the shifting nature of population exposure in the daily cycle and the need to move beyond conventional residence-based demographic data sources to improve risk analyses. The proposed fine-scale maps of human exposure to seismic intensity are mainly aimed at benefiting visualization and communication of earthquake risk, but can be valuable in all phases of the disaster management process where knowledge of population densities is relevant for decision-making. © 2012 Author(s).


Sousa P.M.F.,Institute Investigacao Cientifica Tropical | Sousa P.M.F.,New University of Lisbon | Videira M.A.M.,Institute Investigacao Cientifica Tropical | Melo A.M.P.,Institute Investigacao Cientifica Tropical
FEBS Letters | Year: 2013

The Escherichia coli formate:oxygen oxidoreductase supercomplex (FdOx) was investigated with respect to function and composition. Formate oxidoreductase activity was detected in blue native polyacrylamide gel electrophoresis (BN-PAGE) resolved membranes of E. coli, which were also capable of cyanide sensitive formate:oxygen oxidoreductase activity. The latter was compromised in strains devoid of specific oxygen reductases, particularly, in those devoid of cytochrome bo3 or bdI. A principal component analysis (PCA) integrating E. coli aerobic respiratory chain gene transcription, enzyme activity and growth dynamics was performed, correlating formate:oxygen oxidoreductase activity and the transcription of the genes encoding cytochromes bo3 and bdI, and corroborating previous evidence that associated these complexes in FdOx. © 2013 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.


Barroso-Batista J.,Instituto Gulbenkian Of Ciencia | Sousa A.,Instituto Gulbenkian Of Ciencia | Lourenco M.,Instituto Gulbenkian Of Ciencia | Bergman M.-L.,Instituto Gulbenkian Of Ciencia | And 5 more authors.
PLoS Genetics | Year: 2014

The accumulation of adaptive mutations is essential for survival in novel environments. However, in clonal populations with a high mutational supply, the power of natural selection is expected to be limited. This is due to clonal interference - the competition of clones carrying different beneficial mutations - which leads to the loss of many small effect mutations and fixation of large effect ones. If interference is abundant, then mechanisms for horizontal transfer of genes, which allow the immediate combination of beneficial alleles in a single background, are expected to evolve. However, the relevance of interference in natural complex environments, such as the gut, is poorly known. To address this issue, we have developed an experimental system which allows to uncover the nature of the adaptive process as Escherichia coli adapts to the mouse gut. This system shows the invasion of beneficial mutations in the bacterial populations and demonstrates the pervasiveness of clonal interference. The observed dynamics of change in frequency of beneficial mutations are consistent with soft sweeps, where different adaptive mutations with similar phenotypes, arise repeatedly on different haplotypes without reaching fixation. Despite the complexity of this ecosystem, the genetic basis of the adaptive mutations revealed a striking parallelism in independently evolving populations. This was mainly characterized by the insertion of transposable elements in both coding and regulatory regions of a few genes. Interestingly, in most populations we observed a complete phenotypic sweep without loss of genetic variation. The intense clonal interference during adaptation to the gut environment, here demonstrated, may be important for our understanding of the levels of strain diversity of E. coli inhabiting the human gut microbiota and of its recombination rate. © 2014 Barroso-Batista et al.


Pereira M.M.A.,New University of Lisbon
Current Organic Chemistry | Year: 2012

Due to its particular properties the use of ionic liquids in organic transformations is maturing. Immobilized ionic liquids, supported in different substrates or used as functional support, have found important applications in the last decade. In this review, a critical overview of the applications of immobilized ionic liquids in organic transformations as catalysts or to carry reagents or nanoparticles will be presented. Special relevance will be attributed to green procedure, use of nontoxic solvents and recover and reuse of materials. Metal catalysts, organocatalysts, asymmetric aldol reactions, functional group transformations, oxidations, reductions, biooligomer synthesis like oligosaccharide and peptide synthesis will be some of the transformations to be considered. © 2012 Bentham Science Publishers.


Pereira M.M.A.,New University of Lisbon
Mini-Reviews in Organic Chemistry | Year: 2012

Due to their particular properties the use of ionic liquids is growing. Because of their chiral discriminated properties chiral ionic liquids synthesized from mono, polysaccharides or cyclodextrins are used as catalysts in asymmetric synthesis, chiral selectors in NMR studies or as stationary phases in chiral chromatographic analysis. Chiral carbohydrate ionic liquids are a recent topic and only few examples in the literature describe applications of ionic liquids derived from monosaccharides. Isomannide and isosorbide are the most explored and demonstrate important features as chiral selectors and as catalysts in asymmetric synthesis. Carbohydrate imidazolium salts have been explored as soluble supports for oligosaccharide synthesis and polymers resulting from carbohydrate ionic liquids polymerization have been reported. Cyclodextrin ionic liquids have been described and the ability to produce inclusion complexes was explored. © 2012 Bentham Science Publishers.


Caeiro S.,Polytechnic Institute of Lisbon | Ramos T.B.,New University of Lisbon | Huisingh D.,University of Tennessee at Knoxville
Journal of Cleaner Production | Year: 2012

Communication about very complex problems like household sustainable consumption in simple terms is still a major challenge. Despite the diversity of tools to measure household consumption, clearer indicators are needed to more effectively communicate with the general public. The main objective of this research was to develop an approach to define the main procedures and criteria to built household sustainable consumption assessment tools based on indicator sets. A review of available household sustainable consumption assessment metrics and related initiatives was conducted; this included a comparative analysis of the different approaches. The review revealed that the majority of these initiatives are focused upon specific domains (e.g. energy or waste), but none used an integrated approach in the sustainable consumption domains. Furthermore, it was found that few methods used indicators to measure and assess household sustainable consumption. Principal components and a checklist of key good-practice factors that a household sustainable consumption indicator system should include were developed. Due to the need to communicate effectively, to engage stakeholders and to address the complexity involved in the measurement and assessment of household sustainable consumption, the proposed integrated approach was designed to evaluate household sustainable consumption. © 2011 Elsevier Ltd. All rights reserved.


The impact of dementia on informal or family caregivers became a public health issue. One well-established tool for the assessment of emotional, physical and social impact on caregivers is the Zarit Burden Interview. Worldwide, it is widely used in epidemiological studies, drug or psychosocial clinical trials, and health services research. The original focus on burden among dementia caregivers has spread to other clinical contexts, mostly in old age and palliative care. Given these diverse applications, issues around the validity and reliability of national translations are crucial to assure that all evidence gathered is indeed of high quality. Moreover, caution is needed on the use of cut-offs for categorizing levels of caregiver strain or of subscales derived from recurrent exploratory factor analyses in small-scale local studies. As with other translations of measures in the health field, researchers and clinicians in Portugal must be aware of how to address bias in using the Zarit Burden Interview and interpreting findings. © Ordem dos Médicos 2014.


Bras A.,Polytechnic Institute of Setubal | Leal M.,Polytechnic Institute of Setubal | Faria P.,New University of Lisbon
Construction and Building Materials | Year: 2013

The aim of this paper is to demonstrate the advantage of cork-mortars for renderings when compared to EPS-mortars, from a thermal characteristics point of view, namely in steady and unsteady conditions. It was intended to develop specific rendering mortars able to be applied in thermal bridges to reduce condensation effects and heat transfer in buildings envelopes. The impact of this solution is significant, especially in building typologies as framed reinforced concrete structures. Cement mortars and cement-EPS mortars are used as a reference as their properties are easily recognized compared to cement-cork mortars, which are made with by-products from the cork industry. Several studies were made concerning fresh and hardened state behaviour of mortars, namely: rheological and mechanical properties, microstructure evolution with time and thermal behaviour. For a cement based mortar, different cork dosages (from 0% to 80%) were tested (as sand replacement by mass). Microstructural analyses show that the mechanical properties of cement-cork blends are not only controlled by cork's low density, but also by interaction of cork extractives with the cement hydration process. Thermal conductivity presents a linear decrease for an increasing cork dosage in mortars. Concerning the effect on thermal delay, cork-mortars seem to behave better than EPS-mortars. © 2013 Elsevier Ltd. All rights reserved.


Lita Da Silva J.,New University of Lisbon
Computers and Mathematics with Applications | Year: 2015

In this paper we use Chebyshev polynomials to derive a general expression for integer powers of real anti-tridiagonal matrices with constant anti-diagonals and null northeast-to-southwest diagonal. © 2