Modelling evapotranspiration of soilless cut roses "Red Naomi" based on climatic and crop predictors

Original PaperThis study aimed to estimate the daily crop evapotranspiration (ETc) of soilless cut ‘Red Naomi’ roses, cultivated in a commercial glass greenhouse, using climatic and crop predictors. A multiple stepwise regression technique was applied for estimating ETc using the daily relative humidity, stem leaf area and number of leaves of the bended stems. The model explained 90% of the daily ETc variability (R2 = 0.90, n = 33, P < 0.0001) measured by weighing lysimeters. The mean relative difference between the observed and the estimated daily ETc was 9.1%. The methodology revealed a high accuracy and precision in the estimation of daily ETcinfo:eu-repo/semantics/publishedVersio

It takes two flints to make a fire: Understanding work engagement at the team level

The main goal of the present thesis is to propose, validate and understand the construct of team work engagement. The thesis includes one theoretical article and five empirical articles. Theoretically, team work engagement is defined as a shared emergent state that mediates the relationship between interpersonal team processes and team effectiveness. In studies 1 and 2, we aimed at validating the construct. Our results indicate that work engagement can be empirically assessed at the individual and team levels. Moreover, the findings support the proposed mediation role of team work engagement. Study 3 was aimed at investigating a specific interpersonal team process variable, team conflict, in the relationship between team resources and team effectiveness. Results show that task and relationship conflict are contextual variables that have a negative impact on team work engagement. Task conflict, however, can strengthen the positive relationship between team work engagement and team performance. In study 4 we investigated the cross-level influence of team work engagement and individual positive emotions on perceptions of team viability. Our results indicate that team-level states have a “protective” effect on this specific outcome. Finally, study 5 takes a qualitative look at team members’ interactions, looking for patterns that characterize highly engaged teams. We found that positive affective interactions are frequent within these teams, but that the relationship between affective interactions and team objective performance is not linear. This work contributes to our understanding of teamwork, particularly its affective properties. The thesis also feeds the discussion of multilevel phenomena in organizational life, highlighting relevant clues for managing teams.A presente tese tem como objectivo propor, validar e explorar a emergência do constructo de “work engagement” de equipa. Apresenta-se uma proposta teórica, e cinco estudos empíricos. Teoricamente, define-se “work engagement” de equipa como um estado emergente partilhado, mediador da relação entre processos interpessoais de equipa e a eficácia da mesma. Os dois primeiros estudos procuraram validar o constructo. Os resultados mostram que este é distinto ao nível individual e de equipa, e suportam o referido papel mediador. O estudo 3 analisa um processo interpessoal específico, o conflito, na relação entre os recursos da equipa e a sua eficácia, mediada pelo “work engagement” de equipa. O conflito relacional e de tarefa apresentam uma relação negativa com o “work engagement” de equipa. Porém, o conflito de tarefa influencia positivamente a relação entre o “work engagement” de equipa e o seu desempenho. No estudo 4 investigou-se a influência “cross-level” entre o “work engagement” de equipa e as emoções positivas individuais para a percepção da viabilidade da equipa. Os resultados indicam que os estados colectivos têm um efeito “protector” para esta variável. Finalmente, o estudo 5 apresenta uma abordagem qualitativa, procurando padrões de interacção que caracterizam equipas de elevado “engagement”. Estas equipas demonstram frequentes interacções afectivas com valência positiva, mas a relação entre estas e a performance objectiva das equipas não é linear. Este trabalho contribui simultaneamente para a compreensão do trabalho em equipa, nomeadamente da sua dimensão afectiva, e para a discussão de constructos de natureza multinível, salientando pistas relevantes para a gestão de equipas

Prevalência de sobrepeso e obesidade e sua associação com polimorfismos em escolares

The nutritional status is directed to the health of the child, influencing its process of growth and development. The objective of the study was to investigate the nutritional status and to identify the existence of the association with ACTN3 (R577X) and ECA I / D gene polymorphisms in public and private school students. It is a study with a crosssectional design from November 2015 to July 2016. All the studies enrolled in school are included and are frequently considered as classes. To collect the data on an anthropometric evaluation by means of measures of weight and height. Subsequently, the data were analyzed for the use of the Stata 13.0 program. After an evaluation of the results, the following results can be observed regarding nutritional status, observing that only 0.6% (n = 1) were evaluated with 57.8% as eutrophic, while 16.5% (N = 76) and 23.7% (n = 109) were overweight and obese. Regarding the RCT polymorphism, 223 individuals were found to be DD (52.5%), 131 ID (30.8%) and 71 II (16.70). The prevalence of the D allele was 68% and the I allele was 32%. Regarding the ACTN3 polymorphism, 155 RR (38.8%), 161 RX (40.25%) and 84 XX (21%) individuals were observed. The prevalence of the 59% R allele and the X allele was 41%. No association was found between the nutritional status of the children and the polymorphisms studied. The two genes show a balance of distribution disequilibrium for Hardy-Weinberg in the sample, which should be studied to verify if this imbalance also reflects an adult population of Arroio Grande.Sem bolsaO estado nutricional está diretamente ligado à saúde da criança, influenciando no seu processo de crescimento e desenvolvimento. O estudo teve por objetivo investigar o estado nutricional e identificar a existência da associação com os polimorfismo R577X da ACTN3 e ECA I/D, em escolares do ensino da rede pública e privada. É um estudo com delineamento transversal no período de novembro de 2015 a julho de 2016. Foram incluídos no estudo todos os escolares matriculados e que estavam frequentando regularmente as aulas. Para a coleta dos dados foi realizada avaliação antropométrica por meio das medidas de peso e estatura. Posteriormente, os dados foram analisados através da utilização do programa Stata 13.0. Após a avaliação dos dados pode-se observar os seguintes resultados, em relação ao estado nutricional observa-se que apenas 0,2% (n=1) foram classificados com magreza e 57,8% como eutróficos, enquanto que 16,5% (n=76) e 23,7% (n=109) foram classificados com sobrepeso e obesidade, respectivamente. Em relação ao polimorfismo da ECA, encontrou-se 223 indivíduos DD (52,5%), 131 ID (30,8%) e 71 II (16,70). A prevalência do alelo D foi de 68% e do alelo I foi de 32%. Quanto ao polimorfismo da ACTN3 observou-se 155 indivíduos RR (38,8%), 161 RX (40,25%) e 84 XX (21%). A prevalência do alelo R de 59% e do alelo X foi de 41%. Não foi encontrada associação entre o estado nutricional das crianças e os polimorfismos estudados. Os dois genes apresentaram estarem em desequilíbrio de distribuição quanto a Hardy-Weinberg na amostra, o que deverá ser estudado para verificar se este desequilíbrio também reflete a população adulta de Arroio Grande

Experimental and analytical study of concrete structures reinforced with GFRP bars

The rational use of natural, economic and social resources in order to ensure the sustainability and a long-term balance has become one of the largest global concerns. In the civil engineering field, the limited durability of steel reinforced concrete structures, especially in aggressive environments, and the high costs of the repair and maintenance operations have motivated the search for alternative materials and solutions to steel. One of these alternative reinforcements is the glass fibre reinforced polymer (GFRP) bars due to their immunity to corrosion, which is an important advantage when comparing to steel. However, several factors such as the novelty in the market, the high fabrication costs, the different design philosophies and the uncertainties of its behaviour with the concrete have been delaying the use of the GFRP bars in a larger scale. This thesis aims to contribute to the scientific knowledge of the GFRP reinforced concrete, as it studies its behaviour and design. The research work is mainly experimental and is based on a campaign with 24 full-scale reinforced concrete (RC) beams 4.30 m long and rectangular crosssection of 0.25 x 0.40 m2, divided into two groups with different purposes: - 18 beams to study the performance of different GFRP bar layouts as shear reinforcement; - 6 beams to assess the behaviour of a rehabilitation solution with GFRP bars to replace the deteriorated flexural steel reinforcement. The specimens of the first group were designed to fail due to shear with four different GFRP shear reinforcement solutions: 1) closed hoop GFRP stirrups, 2) two C shaped GFRP bars forming a stirrup, 3) two double headed GFRP bars and 4) two simple straight GFRP bars. Two shear reinforcement ratios with different spacing were also tested with the closed hoop GFRP stirrups. For each GFRP shear reinforcement layout, three different longitudinal stiffnesses were considered using steel and GFRP bars with different ratios. The beam specimens were tested until failure under a four point loading set-up and both the serviceability and the ultimate performance were analysed. The results were reported in terms of deflections, crack pattern, crack width, strains in the longitudinal and shear reinforcements, ultimate load capacity and failure modes. The different shear layouts were compared regarding their load carrying performance and their field implementation easiness. The design of the beams and their result predictions were made according to the existing guidelines and codes. It was concluded that the closed hoop stirrups and the C-stirrups were the most efficient and that the beams load capacity was highly underestimated by the GFRP codes. To improve the design formulas of these codes, different values for the limit strains and for the strut angle were proposed. The double headed bars as shear reinforcement were also efficient in the cases with higher longitudinal stiffness because it contributed to keep the integrity of the beam by exhibiting low deflections and crack widths. It was observed that a wide crack at the end of these bars highly compromises the anchorage function of the head. The solution of the simple straight bars was not effective because of the lack of anchorage length. The idea for the second group of beams was inspired on the RC structures with deteriorated bottom concrete due to the corrosion of the longitudinal steel reinforcement. Actually, no steel corrosion was considered in these specimens, but they were concreted in two phases to simulate the replacement of the deteriorated concrete, starting at the stage after its complete removal. The rehabilitation procedure consisted on the insertion of the longitudinal GFRP bars and the concreting of a new bottom layer in the beam. Two solutions with different GFRP longitudinal cross-section areas were designed according to the existing guidelines, one to restore the ultimate load capacity of the original beam, and the other to maintain the deflection of the original beam. The ends of the GFRP bars were conic heads to compensate their lower anchorage length. The rehabilitated beam specimens were subjected to 3 point bending tests until failure, and their service and ultimate behaviour were analysed. Results are presented in terms of deflection, crack pattern, mid-span crack width, reinforcement strains, ultimate flexural capacity and failure modes. It was concluded that this technique was effective for both the serviceability and ultimate limit states of the rehabilitated beam, as it was able to restore the deflection and the load capacity of the original beam, and that the existing GFRP design documents can be used. Although this was mainly an experimental research work, a simple but reliable two-dimensional finite element (FE) model was defined using ATENA software to simulate the tests, which helped to better understand some issues regarding the specimens behaviour and enabled to extrapolate some results of non-tested possibilities. The linear and nonlinear behaviour of all materials was adequately modelled by appropriate constitutive laws. Furthermore, numerical results were compared with the experimental results. Results show that, in general there was a good agreement between the overall modelling results and the experimental ones. The constructed models were able to predict the experimental behaviour in terms of ultimate capacity and load-deflection curves. Regarding the first group of beams, two additional stirrups spacing were modelled in order to clarify its influence in the shear capacity. It was simulated different longitudinal reinforcement ratios to assess its influence in the shear capacity. As a final remark, the results of the present work show that the use of GFRP bars is viable in RC structures, which contributes to more durable structures in long-term. This material can be used as longitudinal and shear reinforcement of new structures and as a rehabilitation solution to replace the corroded steel in deteriorated structures

Difficulties of public legislation for the acquisition of goods and services

The role of purchasing is increasingly important for companies in the public sector, which are increasingly seek efficiency and effectiveness in their procurement processes. However, public companies need to govern all their activities respecting the legal procedures which sometimes leads to some operational difficulties, resulting in inefficiencies in the procurement process. This dissertation aims to identify opportunities for improvement in the procurement process in the public sector, looking specifically at the difficulties felt as a result of legally imposed procedures. The adopted methodology is based on a dissertation per case study applied to the public procurement process in the Portuguese context. A public university - ISCTE - Instituto Universitário de Lisboa, was used as an example, but the proposed approach could be applied to other public entities. Direct observations, informal and formal interviews, and necessary documentation were collected for data analysis. The procurement process was described based on the internal procedures adopted, and based on the legal terms, since these are organizations that are under the jurisdiction of the Public Procurement Code. The results of the research allowed to conclude that the application of lean thinking in public entities can be useful in the fight against the difficulties felt in the application of the law in the public procurement processes. To conclude this dissertation, three proposals to improve the procurement process of a public entity were presented. If implemented, these proposals eliminate waste and create value, being in accordance with the philosophy of lean thinking.O papel das compras é cada vez mais importante para as empresas do setor público, as quais procuram cada vez mais eficiência e eficácia nos seus processos de compra. No entanto, as empresas públicas precisam de reger toda a sua atividade respeitando os procedimentos legais, o que por vezes traz algumas dificuldades de operacionalização, resultando em ineficiências no processo de compra. Esta dissertação surge neste contexto, tendo como objetivo identificar oportunidades de melhoria no processo de aquisição no setor público, olhando especificamente para as dificuldades sentidas como resultado dos procedimentos impostos legalmente. A metodologia adotada baseia-se numa dissertação por estudo de caso aplicado ao processo de contratação pública no contexto português. Uma universidade pública - ISCTE - Instituto Universitário de Lisboa, foi usada como exemplo, podendo, no entanto, a abordagem proposta ser aplicada a outras entidades públicas. Observações diretas, entrevistas formais e informais, e documentação necessária foram recolhidas para análise de dados. O processo de compra foi descrito com base nos procedimentos internos adotados e com base nos termos legais, uma vez que são organizações sob jurisdição do Código de Contratação Pública. Os resultados da pesquisa permitiram concluir que a aplicação do pensamento lean em entidades públicas pode ser útil no combate às dificuldades sentidas na aplicação da lei nos processos de compra pública. Para concluir esta dissertação, foram apresentadas três propostas de melhoria ao processo de compra de uma entidade pública. Se implementadas, estas propostas eliminam desperdícios e criam valor, estando em concordância com a filosofia do pensamento lean

Machine learning: Challenges and opportunities on credit risk

The constant challenge in anticipating the risk of default by borrowers has led financial institutions to develop techniques and models to improve their credit risk monitoring, and to predict how likely it is for certain customers to default on a loan, as well as how likely it is for others to meet their financial obligations. Thus, it is interesting to investigate how financial institutions can anticipate this occurrence using Machine Learning algorithms. This dissertation aims to demonstrate the power of Machine Learning algorithms in credit risk analysis, focusing on building the models, training them, and testing the data, and presenting the opportunities and challenges of Machine Learning that are still open to developing future studies. For this purpose, we present two Machine Learning classification algorithms: Decision Trees and Logistic Regression. In addition, numerical results obtained from various comparisons of these algorithms, which were programmed and ran in Python using the Jupyter Notebook application, are also presented. The initial sample data, consisting of 850 observations, contained credit details about borrowers in the United States of America, and is freely available data. To check the model execution and performance, between Logistic Regression and Decision Trees, we used measures such as AUC, precision and F1-score.O constante desafio na antecipação do risco de incumprimento por parte dos tomadores de crédito, levou a que as instituições financeiras desenvolvessem técnicas e modelos de forma a melhorar a sua monitorização do risco de crédito, e antever o quão provável será para determinados clientes entrar em incumprimento, assim como o quão provável será para outros de cumprirem com as suas obrigações financeiras. Portanto, interessa averiguar como as instituições financeiras podem antecipar esta ocorrência beneficiando de algoritmos de Machine Learning. A presente dissertação pretende demonstrar o poder dos algoritmos de Machine Learning na análise de risco de crédito, com foco no processo de construção dos modelos, treinando-os e testando os dados, e apresentar as oportunidades e os desafios de Machine Learning que ainda estão em aberto para desenvolver futuros estudos. Para esse propósito, apresentamos dois algoritmos de classificação de Machine Learning: as Árvores de Decisão e a Regressão Logística. Adicionalmente, também se apresenta os resultados numéricos obtidos entre várias comparações desses algoritmos que foram programados e corridos em Python, utilizando a aplicação Jupyter Notebook. Os dados da amostra inicial, constituída por 850 observações, contêm detalhes de crédito sobre os tomadores de empréstimos nos Estados Unidos da América, sendo os dados de livre acesso e uitilização. Para verificar a execução e a performance do modelo, entre Regressão Logística e Árvores de Decisão, usamos medidas como o AUC, precisão e F1-score

New developments on the pathogenesis of systemic lupus erythemstosus

Tese de doutoramento, Medicina (Pediatria), Universidade de Lisboa, Faculdade de Medicina, 2018Systemic Lupus Erythematosus (SLE) is a challenging autoimmune disease, with a complex etiopathogenesis and an unpredictable clinical course. In a large cohort of juvenile-onset SLE patients, we found that major infections were common, were associated with active disease and its treatment, and resulted in noteworthy morbidity. New biomarkers to guide the judicious use of immunosuppressive drugs and new treatment strategies with fewer side effects would, therefore, have an enormous impact in the management of these patients. In order to reach these goals we used the modern tools of molecular biology and focused on two of the most important complications of SLE: lupus nephritis and macrophage activation syndrome. Firstly, we identified the kidney lupus nephritis specific microRNA (miRNA) signature, which reflected mainly cell proliferation. MiRNAs are noncoding RNAs responsible for post-transcriptional gene silencing. These key regulatory molecules control the expression of multiple genes, so its dysregulation can contribute to sustained pathology. We showed that miR-26a and miR-30b were significantly decreased in the kidneys and urine of lupus nephritis patients. In vitro, the knockdown of miR-26a and miR-30b caused the proliferation of human mesangial cells and increased the expression of genes related to the cell cycle, including CCNE2, E2F8, MAD2L1, MYBL1 and POLQ. The Human Epidermal Growth Factor Receptor 2 (HER2) is a protein previously known to regulate miR-26a and miR-30b expression. Trastuzumab, a monoclonal antibody against HER2, used in breast cancer treatment, produces therapeutic actions precisely by up-regulating miR-26a and miR-30b. In human mesangial cells we also found that trastuzumab increases these two miRNAs. We hypothesized that HER2 also played a role in the pathogenesis of lupus nephritis and indeed we identified a dramatic overexpression of HER2 in the glomeruli and tubular compartments of the kidneys of lupus nephritis patients. The same pattern was not seen in the kidneys of healthy individuals or in other proliferative glomerulonephritides, including post-streptococcus glomerulonephritis, IgA nephropathy and granulomatosis with polyangiitis. Furthermore, in the lupus-prone NZM2410 mice we identified a highly increased expression of HER2, which correlated with disease activity. Finally, we showed that urinary HER2 was significantly increased in lupus nephritis and that its levels increased during flares, were higher in class III and class IV lupus nephritis and correlated with urinary proteincreatinine and monocyte chemoattractant protein 1 (MCP1) and vascular cell adhesion protein 1 (VCAM1) levels. We, therefore, established a strong rationale to use trastuzumab to block HER2 and decrease cell proliferation and damage in lupus nephritis. Regarding the macrophage activation syndrome, we were interested in the characterization of hemophagocytes. These are activated macrophages that have engulfed other hematopoietic cells. Traditionally they have been associated with the development of cytopenias in several life-threatening cytokine storm syndromes. New data have challenged this concept, since pancytopenia occurs in the absence of hemophagocytosis in mice and, in humans, over 40% of patients with macrophage activation syndrome do not have hemophagocytes in bone marrow aspirates. On the other hand, subclinical hemophagocytosis is detected in more than 50% of patients with systemic juvenile idiopathic arthritis, but only 10% develop a life-threatening macrophage activation syndrome. Thus the function and significance of hemophagocytes remained mysterious. Recent evidence demonstrated that environmental factors, particularly the cytokine milieu, determine the macrophage activation status in a continuum ranging from M1 to M2. M1 macrophages, driven by interferon γ, typically acquire proinflammatory properties and are associated with tissue damage, whereas M2 macrophages have more heterogeneous stimuli and functions, being associated with immunoregulation, tissue remodeling and fibrosis. Since interferon γ is the hallmark cytokine of hemophagocytic lymphohistiocytosis, one would expect to find that hemophagocytes express M1 surface receptors. We characterized the transcriptional phenotype of mouse Toll-like receptor 9 (TLR9) – induced hemophagocytes and described the surface phenotype of human bone marrow hemophagocytes. Interestingly, murine hemophagocytes had up-regulation of genes associated with the M2 and not the M1 phenotype. Immunohistochemical analyses in bone marrow samples from a uniquely diverse cohort of patients with hemophagocytic syndromes showed universal staining of hemophagocytes for the M2 marker CD163, but rarely for CD206 or CD64. Collectively, these data support the hypothesis that hemophagocytes have immunoregulatory functions and open new doors for the study of the pathogenesis of this syndrome. Finally, we were interested in characterizing the transcriptome of SLE, by RNAsequencing, in order to better understand the mechanisms that are responsible for chronicity. Monocytes from SLE patients exhibited a globally dysregulated gene expression. The transcriptome was not simply altered by the activation of a set of genes, but was also qualitatively different. Splicing patterns and polyadenylation were significantly altered and SLE monocytes expressed novel transcripts, an effect that was replicated by exposing control monocytes to lipopolysaccharide (LPS). We further identified increased circulating endotoxin in SLE patients, suggesting that chronic microbial translocation could contribute to the immunologic dysregulation in SLE, a new potential disease mechanism. In conclusion, with these different projects, which globally focused on the transcriptome and epigenome of SLE, we identified novel pathways and challenged the current paradigms. We described new mechanisms of disease, including the role of LPS in transforming qualitatively the SLE transcriptome and a putative immunoregulatory function for hemophagocytes. We demonstrated that miR-26a, miR-30b and HER2 control cell proliferation in lupus nephritis and that are promising biomarkers. Most importantly, our work rose the possibility of using anti-HER2 drugs for lupus nephritis management, opening the door to a new treatment strategy in this disease.Fundação Calouste Gulbenkian, Fundação Champalimau

Perfil dos observadores de aves no Parque Natural da Ria Formosa

In the Algarve the potential for birdwatching tourism is widely recognized, especially in the Ria Formosa Natural Park (RFNP). This study aims to describe birdwatchers' profile in the RFNP. For this purpose, a survey was applied. The results show that the most frequent nationalities of birdwatchers are: British (39%), Dutch (17%) and Portuguese (17%). The majority of birdwatchers are male (55%) and married (57%). The average age is 50 years old. They are highly educated (74% have an academic degree). Concerning profession, the most frequent answer was retired (41%). Respondents are committed to the activity as the majority possess special equipment and practice birdwatching in vacations. This study also tests if nationality is related to other characteristics of the birdwatchers, by using the Kruskal-Wallis and the Chi-square tests. Overall, the results of this study highlight that regional management organizations should invest in developing birdwatching in the RFNP.O potencial para o turismo de birdwatching é vastamente reconhecido, especialmente no Parque Natural da Ria Formosa (PNRF). Este estudo tem como objetivo descrever o perfil dos observadores de aves que visitam o PNRF. Para esse propósito, foi aplicado um questionário. Os resultados mostram que as nacionalidades mais frequentes dos observadores de aves são: britânica (39%), holandesa (17%) e portuguesa (17%). A maioria dos observadores de aves é do sexo masculino (55%), sendo o seu estado civil casado (57%). A idade média é de 50 anos. O seu nível educacional é elevado (74% têm um grau académico). Quanto à profissão, a resposta mais frequente foi aposentado (41%). Os inquiridos estão comprometidos com a atividade, pois a maioria possui equipamentos especiais e pratica observação de aves nas férias. Este estudo também testa se a nacionalidade está relacionada com outras características dos observadores de aves, através de testes Kruskal-Wallis e Qui-quadrado. Os resultados deste estudo indicam que as organizações de gestão regional devem investir no desenvolvimento do birdwatching no PNRF.info:eu-repo/semantics/publishedVersio