Determinación de toxinas paralizantes en el jurel (Trachurus trachurus) durante una proliferación de Gymnodinium catenatum: la prevalencia de decarbamoilsaxitoxina en la red trófica marina

This study reports the accumulation of paralytic shellfish toxins (PSTs) in Atlantic horse mackerel (Trachurus trachurus) over a bloom of the toxigenic dinoflagellate Gymnodinium catenatum. High levels of toxins, up to 4800 μg STXeq kg–1, were registered at the peak of the bloom (5.0 103 cells l–1). The suite of individual PSTs was examined. Decarbamoylsaxitoxin (dcSTX) and B1 constituted nearly 90% of toxins (on a molar basis) determined in mackerel. This profile of toxins markedly differs from the known profile of toxins produced by G. catenatum strains isolated from the Portuguese coast, which is dominated by N-sulfocarbamoyl toxins, in particular the C1+2 toxins. The prevalence of the potent dcSTX in the pelagic environment and its transfer through the marine food web is highlighted in this study. Atlantic horse mackerel is identified as a high potential vector of PSTs along the Portuguese coast. This fish species has a central position in the marine food web, being an important predator of zooplankton and at the same time an important diet item of top predators. This study reveals bioaccumulation values that are important for evaluating potential impacts of blooms of PST-producing dinoflagellates on marine ecosystems or their components, such as fish.Este estudio reporta la acumulación de toxinas paralizantes de molusco (PSP) en las muestras de jurel (Trachurus trachurus) durante una proliferación do dinoflagelado Gymnodinium catenatum. Los altos niveles de toxinas PSP, alcanzando un valor máximo de 4800 μg STXeq kg–1, se determinaron en el pico de la proliferación (5.0 103 células l–1). El perfil de toxinas se examinó y se reveló que los compuestos dcSTX y B1 constintuían casi 90% de las toxinas (en base molar) encontrados en las muestras de jurel. Este perfil difiere claramente del perfil de toxinas conocido en cepas de G. catenatum aisladas de la costa portuguesa, que está dominado por toxinas N-sulfocarbamoyl, en particular las toxinas C1+2. Este trabajo muestra la prevalencia de dcSTX el ambiente pelágico y la transferencia de este compuesto a través de la cadena alimentaria. El jurel se identifica como un potencial vector de las toxinas PSP a lo largo de la costa portuguesa. Esta especie de pez tiene una posición central en la cadena alimentaria marina, siendo un importante depredador de zooplancton y, al mismo tiempo un elemento importante de la dieta de los depredadores superiores. Este estudio contribuye con valores ecológicos relevantes para evaluar los potenciales impactos de las proliferaciones de dinoflagelados productores de PST en los ecosistemas marinos o sus componentes, como los peces

Influence of the particle size distribution on the stifness of granitic materials

A presente comunicação apresenta a avaliação das características de deformabilidade obtidas com recurso a um equipamento triaxial de precisão, sobre três granulometrias diferentes da mesma origem geológica (formação granítica), a saber: uma areia siltosa (D50=0.36mm) designada de Areia de Perafita, e dois agregados graníticos, um (0/12.5) e outro (0/31.5). Os ensaios foram realizados sobre provetes reconstituídos por compactação sobre amostras no estado não saturado, tendo-se procedido à medição das pressões intersticiais negativas, de modo a se poderem também analisar os resultados em termos de tensões efectivas. Os resultados obtidos evidenciaram, para um determinado nível de tensão, um aumento do módulo de deformabilidade (normalizado para o mesmo índice de vazios) com a diminuição da dimensão máxima das partículas.In this paper is presented the stiffness of three materials with the same geological origin, a silty sand designed Perafita sand (D50=0.36mm) and two granite aggregates, one (0/12.5) and another (0/31.5). The stiffness of the compacted materials was studied by means of precision triaxial tests. The influence of non-saturation into the stiffness is also studied through triaxial tests with measurements of negative pore water pressures. Such measurements allow the analysis of the mechanical behaviour of the unsaturated materials in terms of effective stresses. The results obtained show, for a certain stress level, an increasing of the Young’s modulus (normalised for a certain void ratio) with the decreasing of the maximum size of particles.GRICES/CNRS – projecto “Security of road and railway infrastructures versus climatic changes

Industrial network membership: Reducing psychic distance hazards in the internationalization of the firm

The network approach to internationalization of the firms has warranted the research focus of many international business scholars. Firms are increasingly involved in international business endeavors and arguably need to learn to adapt to idiosyncratic milieus they encounter in the foreign markets. This paper proposes a conceptual model suggesting that integration in networks strengthens corporate competitiveness in international markets. Network membership provides access to knowledge that facilitates adaptation to the various dimensions - economic, political, legal, cultural ? of the international business environments. Membership in social and business networks are likely to ease internationalization by reducing firms? perceived psychic distance.Networks, internationalization theories, psychic distance

Functional role of macrobenthos in estuarine sediment dynamics

Thesis submitted to the Universidade Nova de Lisboa,Faculdade de Ciências e Tecnologia for the degree of Doctor of Philosophy in Environmental EngineeringEstuaries are areas of high sediment dynamics. Particles in suspension are an important vehicle of several biochemical substances and contaminants. Therefore, the knowledge on the processes ruling sediment dynamics is needed to develop tools for estuarine water quality management. Presently, few numerical models for sediment dynamics incorporate biological interactions with sediment dynamics. The aim of this study is to gain understanding of the macrobenthic influences on cohesive sediment dynamics. The research was focused on the effects of two species of macrobenthos; 1) the cockle Cerastoderma edule (densities of 280 to 1000 ind m-2). Work on this species focused on sediment transport and deposition, by studying the hydrodynamic effect on the sediment removal activity (filtration) and its effects on topography and on the current velocities at the boundary layer 2) The ragworm Nereis diversicolor (densities of 320 to 1200 ind m-2). This work focused on sediment erodability and consolidation by studying the bioturbation effect on changes in the sediment properties,and 3) the effect of contamination (3 nmol Cu g-1 dw) on the bioturbation activity of N. diversicolor and on sediment dynamics. The results from experiments performed in a racetrack and in an annular flume showed that increasing density of C. edule is proportional to increasing sediment topography and related to reduced current velocities near the bed and increased shear velocity (u*), hydrodynamic roughness length and turbulence kinetic energy (TKE). The higher TKE values were related to the presence of active filtering C. edule, producing additional turbulence to the TKE produced by topography. The effect of filtration activity on turbulence is most pronounced at low velocities (u* < 1.5 cm s-1), in agreement with a unimodal response to increased velocities. Increasing densities of N. diversicolor are related to increased sediment shear strength (SS), increased biodiffusion coefficients (Db) and increased erosion rates (ER). This antagonistic effect of increase SS and ER is explained by erosion of bigger aggregates resulting from biological bound sediments. This study provides some evidence that copper contaminated sediments are more stable, as a consequence of decrease in biological response to toxicity, observed in lower values of shear strength and erosion rates. In addition, new methodologies for the determination of some of the parametersinvolved with this research field are suggested.This thesis was financed by Fundação para a Ciência e Tecnologia SFRH/BD/6188/200

Biomarkers for classification and risk assessment of pancreatic cystic neoplasms

Pancreatic cystic lesions (PCLs) are increasing incidental findings due to increased ageing of the population and widespread use of imaging. The main problem in clinical practice has to do with distinguishing the high-risk premalignant and malignant cysts that require surgical treatment from the benign or low-grade dysplastic cysts, which should not be over-treated and might not even require surveillance. The goal of the present work is to perform a comprehensive analysis of biomarkers and diagnostic approaches by Endoscopic Ultrasound with Fine-needle Aspiration (EUS-FNA), in a cohort of patients harboring mostly low-risk cysts under surveillance, which are far more frequent in clinical practice. The PCF analysis performed in this cohort includes studies of genomics (DNA mutations), epigenomics (methylation analysis), metabolomics (glucose), and proteomics (CEA, chromogranin A, NSE), with putative biomarkers encompassing the diagnosis of mucinous and malignant cysts, that require surveillance and surgical resection, respectively. We performed a first meta-analysis comparing current diagnostic methods - CEA and cytology - with KRAS mutations for the diagnosis of mucinous cysts. CEA was the best test for clinically significant cysts (AUC=0.69), cytology performed better in malignant cysts (AUC=0.78), surpassing KRAS mutations (AUC=0.53 and AUC=0.56, respectively). In a second meta-analysis we compared the accuracy of molecular analysis versus micro forceps biopsy (MFB) in the diagnosis of PCLs. The two approaches were identical for diagnosing benign cysts, but molecular analysis was superior for diagnosing both low and high-risk mucinous cysts. In addition to these two meta-analyses, we performed a retrospective study evaluating the added value of KRAS and GNAS mutations in PCF of 52 frozen PCF samples. We conclude that, as compared with conventional tests, these had no added value in the differential diagnosis of PCLs. In another publication, we compared glucose level in PCF with CEA in 82 patients. For mucinous cyst diagnosis, a CEA >192 ng/ml showed an AUC of 0.84 while glucose <50 mg/dl revealed an AUC of 0.86. Besides its higher accuracy, PCF glucose evaluated “on site” with a glucometer is easy, immediate, and requires a minimal amount of PCF. In the next study we sought to determine whether a second EUS-FNA changed the diagnosis or management of pancreatic cysts. We compared the outcome of 105 patients with a single EUS-FNA with that of 23 patients who had a second EUS-FNA. EUS-FNA may be recommended, as it changed management toward surgery in approximately 20% of the patients, particularly with diagnosis of cystic NETs. Following these results, we explored the role of EUS-FNA in small PCLs (<3 cm) in 115 patients with PCLs <3 cm who underwent EUS-FNA. 19/115 were submitted to surgery with 15 malignant or premalignant lesions and the remaining 4 were benign lesions. We conclude that EUS-FNA in lesions <3 cm may improve outcome and cost-effectiveness of surveillance programs, as it confirmed malignancy in 2 out of 5 resected lesions, while it also diagnosed benign cysts who could be released from these programs. In a pilot study with 16 patients, including 4 cystic NETs we aimed at assessing the value of Chromogranin A (CroA) and neuron-specific enolase (NSE) levels in PCF. CroA and NSE levels were higher in cystic NETs with an AUC of 0.94 for CroA and 1 for NSE. These are promising biomarkers to identify pancreatic cystic NETs. Finally, we studied epigenetic changes in the diagnosis of malignant cysts. Methylation changes of GNAS locus were evaluated to understand whether they may contribute to malignant progression of PCLs. Fifty-two samples of PCF were studied. We observed that GNAS locus methylation changes were significantly associated with malignancy. This is the first study to identify methylation changes in the GNAS locus improving diagnosis of malignant PCLs. We end this work proposing a revised diagnostic organogram of PCLs established by current guidelines, that incorporates the results obtained in this dissertation’s research.As lesões quísticas pancreáticas (PCL) têm incidência crescente devido ao envelhecimento da população e ao aumento da utilização dos métodos de imagem. Na prática clínica pretende-se distinguir os quistos mucinosos, de alto risco e malignos, que requerem tratamento cirúrgico, dos quistos benignos ou pré-malignos de baixo risco, que no máximo requerem vigilância. O objetivo do presente trabalho é analisar de forma abrangente, biomarcadores em líquido de quisto pancreático (PCF) obtido por Ecoendoscopia com punção (EUS-FNA), numa coorte de quistos predominantemente de baixo risco sob vigilância imagiológica, que são os mais comuns na prática clínica. A análise de PCF nesta coorte inclui estudos de genómica (mutações no DNA), epigenómica (análise de metilação), metabolómica (glicose) e proteómica (CEA, cromogranina A, NSE), com avaliação de biomarcadores para diagnóstico de quistos mucinosos e quistos malignos, que beneficiam de vigilância e ressecção cirúrgica, respetivamente. Numa primeira meta-análise comparámos a metodologia diagnóstica atual - CEA e citologia - com as mutações do KRAS para diagnóstico dos quistos mucinosos. O CEA foi o melhor teste em quistos clinicamente significativos (AUC=0.69), e a citologia em quistos malignos (AUC=0.78), superando as mutações do KRAS (AUC=0.53 e AUC=0.56, respetivamente). Numa segunda meta-análise comparámos a precisão diagnóstica da análise molecular versus biópsia com micropinça (MFB) no diagnóstico de PCL. As duas abordagens foram idênticas em quistos benignos, mas a análise molecular foi superior em quistos mucinosos tanto de baixo como de alto risco. Além das duas meta-análises, realizámos um estudo retrospetivo para avaliar o valor das mutações do KRAS e do GNAS em 52 amostras de PCF congeladas. Concluímos que não têm valor adicional no diagnóstico diferencial das PCL, relativamente aos testes convencionais. Noutra publicação comparámos o nível de glicose em PCF com o CEA para diagnóstico de quistos mucinosos em 82 doentes. O CEA >192 ng/ml apresentou uma AUC de 0.84 e a glicose <50 mg/dl de 0.86. Além da maior precisão diagnóstica, a glicose avaliada in loco com um glicosímetro, é fácil, imediata e requer um volume mínimo de PCF. No estudo seguinte, avaliámos se uma segunda EUS-FNA alterou o diagnóstico ou a decisão de quistos pancreáticos. Comparámos 105 doentes com uma única EUS-FNA com 23 doentes com uma segunda EUS-FNA. Esta pode ser recomendada, pois cerca de 20% dos doentes foram referenciados para cirurgia após repetição da EUS-FNA, incluindo dois com tumores neuroendócrinos (NET) quísticos. Seguidamente, explorámos o papel da EUS-FNA em pequenas PCL (<3 cm), num estudo com 115 PCL <3 cm. 19/115 foram operadas, correspondendo a 15 lesões malignas ou pré-malignas e 4 benignas. Concluímos que a EUS-FNA em quistos com <3 cm pode melhorar o diagnóstico e o custo-efetividade, pois confirmou malignidade em lesões ressecadas, e diagnosticou quistos benignos que podem ser libertados de vigilância. Num estudo piloto com 16 doentes, incluindo 4 com NET quísticos, avaliámos o valor diagnóstico da cromogranina A (CroA) e da enolase específica neuronal (NSE) em PCF. Os níveis de CroA e NSE foram mais elevados nos NET quísticos, com uma AUC de 0.94 para a CroA e 1 para a NSE. Estes revelaram-se biomarcadores promissores Por fim, estudámos alterações epigenéticas no diagnóstico de quistos malignos. Analisámos a metilação do locus GNAS em PCF para perceber se se associa à progressão maligna de PCL. Estudámos 52 amostras e observámos que a alteração da metilação se associou significativamente a malignidade. Trata-se do primeiro trabalho a avaliar alterações de metilação no locus GNAS no diagnóstico de PCL. Terminamos este trabalho com uma proposta de revisão do organograma de diagnóstico das PCL baseado nas guidelines atuais, que incorpora os resultados desta tese

The orphan adapter protein SLY1 as a novel anti-apoptotic protein required for thymocyte development

<p>Abstract</p> <p>Background</p> <p>SH3 containing Lymphocyte Protein (SLY1) is a putative adapter protein exclusively expressed in lymphocytes which is involved in antigen receptor induced activation. We previously have generated SLY1^Δ/Δmice harbouring a partial deletion in the N-terminal region of SLY1 which revealed profound immunological defects in T and B cell functions.</p> <p>Results</p> <p>In this study, T cell development in SLY1^-/-and SLY1^Δ/Δmice was analysed <it>ex vivo </it>and upon cultivation with the bone marrow stromal cell line OP9. SLY1-deficient thymocytes were compromised in inducing nutrient receptor expression and ribosomal protein S6 phosphorylation, indicating a defect in mTOR complex activation. Furthermore, SLY1 was identified as a novel anti-apoptotic protein required for developmental progression of T cell precursors to the CD4⁺CD8⁺double-positive stage by protecting from premature programmed cell death initiation in developing CD4^-CD8^-double-negative thymocytes. In addition, SLY1 phosphorylation was differentially regulated upon Notch ligand-mediated stimulation and expression of the preTCR.</p> <p>Conclusion</p> <p>Thus, our results suggest a non-redundant role for SLY1 in integrating signals from both receptors in early T cell progenitors in the thymus.</p

Implementação da técnica Silver In Situ Hibridization para avaliação do status do gene EGFR em doentes com CPNPC

Avaliação do estado do gene Epidermal Growth Factor Receptor (EGFR), por Silver In Situ Hibridization (SISH), tem-se destacado como biomarcador preditivo na resposta à terapêutica. O principal objectivo foi optimizar a etapa de recuperação por calor da metodologia automatizada SISH Dual-Colour, em carcinomas pulmonares fixados em formol durante 24 e 72 horas. A optimização levou a um aumento da preservação do contorno nuclear e da intensidade e contraste dos sinais para os dois tempos de fixação, permitindo avaliar o estado do EGFR em 83,3% dos casos em estudo. A SISH Dual-Colour é uma alternativa para avaliar o estado do EGFR.Assessment of the status of the gene Epidermal Growth Factor Receptor (EGFR), by Silver in Situ Hibridization (SISH) has been highlighted as a predictive biomarker in the response to therapy. The main objective was to optimize the recovery stage of heat-automated methodology SISH Dual-Colour in lung carcinoma with 24 and 72 hours of formaldehyde fixation. The optimization led to an increase in the preservation of the nuclear contour, intensity and contrast of the signals for both fixation times, allowing evaluation of EGFR state in 83.3% of studied cases. The SISH Dual-Colour is an alternative to assess the status of EGFR

A dependence modelling study of extreme rainfall in Madeira Island

The dependence between variables plays a central role in multivariate extremes. In this paper, spatial dependence of Madeira Island's rainfall data is addressed within an extreme value copula approach through an analysis of maximum annual data. The impact of altitude, slope orientation, distance between rain gauge stations and distance from the stations to the sea are investigated for two different periods of time. The results obtained highlight the influence of the island's complex topography on the spatial distribution of extreme rainfall in Madeira Island.The authors wish to thank the Portuguese Foundation for Science and Technology (FCT) for the financial support through the PhD grant SFRH/BD/39226/2007, financed by national funds of MCTES. They are also grateful to the Center of Statistics and Applications of the University of Lisbon (CEAUL) for the bibliographical and financial support through the FCT under the projects PEst- OE/MAT/UI0006/2011 and PEst-OE/MAT/UI0006/2014, and to the University of Madeira for the logistic support. The authors wish also to thank the Portuguese Institute for Sea and Atmosphere and namely to Dr. Victor Prior, and the Department of Hydraulics and Energy Technologies of the Madeira Regional Laboratory of Civil Engineering and namely to Dr. Carlos Magro, for providing the rainfall data used in this study. The second author also thanks the Brazilian agency CAPES for the partial financial support during his sabbatical leaveinfo:eu-repo/semantics/publishedVersio

An assessment classification of formative evaluation tools and digital tools

The theme “An assessment classification of formative assessment tools and digital tools” represents the meeting between a theme with a history in education - formative assessment, and another very current theme - the use of digital tools with an emphasis on commonly called apps (digital apps). The formative evaluation presents numerous scientific evidences of its potential in supporting students and teachers in overcoming weaknesses and deficiencies, with very positive impacts in terms of motivation, engagement, achievement and autonomy, thus justifying a study on the difficulties in rooting. Technology can guarantee a greater rootedness and a performance more aligned with inclusive education, considering the student's profile after leaving compulsory education. The qualitative methodology was adopted. The technological environment by nature stands out for its ease and efficiency in the collection, organization and treatment of data, thus meeting, one of the main limitations of formative assessment is the difficulty in collecting data on the interaction of learning and results as well as the analysis of formative feedback and evaluation. The results obtained allowed us to conclude that was possible and a new model of classification of apps for formative evaluation was built. The structure of our model comes from the correspondence between the characteristics and the purposes of the tools and / or techniques of formative assessment, and the potentialities and functionalities of applications for mobile devices, in an intrinsic link to Bloom's Taxonomy (2001). This classification was built from three classifications. One classification focuses on formative assessment techniques and cognitive development goals, another organizes apps by type of pedagogical activities, and finally, another organizes, not apps, but web tools serving cognitive development goals concerning a 1956 version of Bloom's TaxonomyCIEd – _Research Centre on Education, Institute of Education, University of Minho, projects UIDB/01661/2020 and UIDP/01661/2020, through national funds of FCT/MCTES-P