A sufficient optimality condition for delayed state-linear optimal control problems

We give answer to an open question by proving a sufficient optimality condition for state-linear optimal control problems with time delays in state and control variables. In the proof of our main result, we transform a delayed state-linear optimal control problem to an equivalent non-delayed problem. This allows us to use a well-known theorem that ensures a sufficient optimality condition for non-delayed state-linear optimal control problems. An example is given in order to illustrate the obtained result.Comment: This is a preprint of a paper whose final and definite form is with 'Discrete and Continuous Dynamical Systems -- Series B' (DCDS-B), ISSN 1531-3492, eISSN 1553-524X, available at [http://www.aimsciences.org/journal/1531-3492]. Paper Submitted 31/Dec/2017; Revised 13/April/2018; Accepted 11/Jan/201

Global analysis of the sugarcane microtranscriptome reveals a unique composition of small RNAs associated with axillary bud outgrowth

Axillary bud outgrowth determines shoot architecture and is under the control of endogenous hormones and a fine-tuned gene-expression network, which probably includes small RNAs (sRNAs). Although it is well known that sRNAs act broadly in plant development, our understanding about their roles in vegetative bud outgrowth remains limited. Moreover, the expression profiles of microRNAs (miRNAs) and their targets within axillary buds are largely unknown. Here, we employed sRNA next-generation sequencing as well as computational and gene-expression analysis to identify and quantify sRNAs and their targets in vegetative axillary buds of the biofuel crop sugarcane (Saccharum spp.). Computational analysis allowed the identification of 26 conserved miRNA families and two putative novel miRNAs, as well as a number of trans-acting small interfering RNAs. sRNAs associated with transposable elements and protein-encoding genes were similarly represented in both inactive and developing bud libraries. Conversely, sequencing and quantitative reverse transcription-PCR results revealed that specific miRNAs were differentially expressed in developing buds, and some correlated negatively with the expression of their targets at specific stages of axillary bud development. For instance, the expression patterns of miR159 and its target GAMYB suggested that they may play roles in regulating abscisic acid-signalling pathways during sugarcane bud outgrowth. Our work reveals, for the first time, differences in the composition and expression profiles of diverse sRNAs and targets between inactive and developing vegetative buds that, together with the endogenous balance of specific hormones, may be important in regulating axillary bud outgrowth

Obesity influence on perceived physical overload during vertical handling loads - A preliminary study

Obesity prevalence is increasing among the Portuguese workforce, similarly to other industrial countries. Obesity seems to negatively affect the individuals’ work capacity. Tasks with vertical handling loads, including lifting and lowering, are very common in occupational contexts. With the aim of studying the possible effect of obesity on workers’ physical overload during vertical handling loads, psychophysical data were collected from a total of 14 participants with different obesity levels (non-obese, high level of obesity and very high level). The participants were asked to go through 6 lifting trials with different occupational conditions and, for each task tested, they reported physical loading by using the Borg’ “Category Ratio-10” (CR-10) scale. The obtained results in this preliminary study are not conclusive about the obesity influence on perceived physical overload during vertical handling loads. Accordingly, this study should be continued, by considering a statistically valid sample and other psychophysical techniques that can complement the CR10 scale results

Removal of polycyclic aromatic hydrocarbons in water, using byproducts of cork industry

Os Hidrocarbonetos Aromáticos Policíclicos (HAPs) são contaminantes persistentes em meio aquoso. Estes compostos são conhecidos pelas suas propriedades carcinogénicas, mutagénicas e genotóxicas. O principal objetivo deste trabalho consistiu na avaliação das potencialidades de subprodutos da indústria corticeira, como adsorventes alternativos para a remoção de cinco HAPs em meio aquoso: benzo(a)pireno, benzo(ghi)perileno, benzo(b)fluoranteno, benzo(k)fluoranteno e indeno(1,2,3-cd)pireno. A metodologia analítica para quantificar os HAPs envolveu a preparação das amostras, através da técnica de extração em fase sólida (SPE), e a quantificação dos compostos analisados por cromatografia líquida com detetor de fluorescência (LC-FLD). O método foi otimizado e validado, obtendo-se limites de quantificação de 0,004 μg/L para todos os HAPs. Os estudos incidiram na utilização de uma amostra de cortiça, pó de aglomerado de cortiça expandida (PACE), obtida por aglutinação de cortiça em condições hidrotérmicas, a qual nos estudos preliminares revelou desempenho semelhante aos carvões ativados. Com exceção do benzo(ghi)perileno, os resultados mostram que o processo de adsorção dos HAPs na amostra PACE segue uma cinética de pseudo-segunda ordem e as isotérmicas ajustam-se ao modelo de Langmuir.Polycyclic Aromatic Hydrocarbons (PAHs) are persistent contaminants present in aqueous media. These compounds are known for their carcinogenic, mutagenic and genotoxic properties. The main objective of this work was to evaluate the potential of cork industry by-products as alternative adsorbents for the removal of five PAHs in aqueous media: benzo(a)pyrene, benzo(ghi)perylene, benzo(b)fluoranthene, benzo(k)fluoranthene e indeno( 1,2,3-cd)pyrene. The analytical methodology used to quantify PAHs consisted in the first step of sample preparation using solid phase extraction (SPE) technique, followed by quantification by liquid chromatography with a fluorescence detector (LC-FLD). The method was optimized and validated, yielding limits of quantification of 0.004 μg L-1 for all PAHs. The studies have focused on the use of a sample cork (PACE), obtained by agglutination of cork under hydrothermal conditions, which in preliminary studies attained removal efficiencies similar to those of activated carbons. With the exception of benzo(ghi)perylene, the results reveal that adsorption process of PAHs on sample PACE obey to the pseudo-second order kinetic equation and to the Langmuir model.Este trabalho foi suportado financeiramente pelo programa QREN-COMPETE, através do projeto de investigação Watercork (nº 2009/5523)

Currículo e didática crítica na construção da identidade profissional docente

Atas do XI Colóquio sobre Questões Curriculares, VII Colóquio Luso-Brasileiro & I Colóquio Luso-Afro-Brasileiro de Questões CurricularesO presente trabalho inscreve-se no âmbito da investigação, em curso, do Doutoramento em Ciências da Educação na Universidade do Minho, na linha de pesquisa de Desenvolvimento Curricular. Esta comunicação traz à tona questões que envolvem o currículo nos cursos de licenciaturas para a formação de professores no Instituto Federal de Educação, Ciência e Tecnologia do Rio Grande do Norte, IFRN, Brasil. A partir do conjunto de conhecimentos contemplados na disciplina de Didática, a qual compõe o núcleo pedagógico do referido currículo, tratamos aqui de um recorte epistemológico que evidencia os conhecimentos da Didática, na perspectiva crítica, como norteadores de uma construção reflexiva da identidade profissional docente. Nosso objetivo geral é discutir o potencial curricular da Didática em um currículo praticado na formação inicial para a docência e suas interfaces com os construtos identitários. As referencias teóricas do estudo balizam-se em produções do campo da Didática crítica, com ênfase em Freire (2006), Candau (2002), Rios (2010). Os conhecimentos e princípios da didática sinalizam uma formação e uma identidade profissional pautadas na reflexão do fazer pedagógico, nos processos de conscientização sobre a dimensão social e ética contidas no ser professor, bem como valorizam o fazer técnico-instrumental, o saber científico e o saber ético. Em síntese, o estudo compreende e defende os conhecimentos críticos da didática como precursores de uma conscientização humanizadora e autoformativa na construção da identidade profissional docente desde a formação inicial dos licenciandos.Fundação para a Ciência e a Tecnologia (FCT

Environmental risk assessment in a contaminated estuary: an integrated weight of evidence approach as a decision support tool

Environmental risk assessment of complex ecosystems such as estuaries is a challenge, where innovative and integrated approaches are needed. The present work aimed at developing an innovative integrative methodology to evaluate in an impacted estuary (the Sado, in Portugal, was taken as case study), the adverse effects onto both ecosystem and human health. For the purpose, new standardized lines of evidence based on multiple quantitative data were integrated into a weight of evidence according to a best expert judgment approach. The best professional judgment for a weight of evidence approach in the present study was based on the following lines of evidence: i) human contamination pathways; ii) human health effects: chronic disease; iii) human health effects: reproductive health; iv) human health effects: health care; v) human exposure through consumption of local agriculture produce; vi) exposure to contaminated of water wells and agriculture soils; vii) contamination of the estuarine sedimentary environment (metal and organic contaminants); viii) effects on benthic organisms with commercial value; and ix) genotoxic potential of sediments. Each line of evidence was then ordinally ranked by levels of ecological or human health risk, according to a tabular decision matrix and expert judgment. Fifteen experts scored two fishing areas of the Sado estuary and a control estuarine area, in a scale of increasing environmental risk and management actions to be taken. The integrated assessment allowed concluding that the estuary should not be regarded as impacted by a specific toxicant, such as metals and organic compounds hitherto measured, but by the cumulative risk of a complex mixture of contaminants. The proven adverse effects on species with commercial value may be used to witness the environmental quality of the estuarine ecosystem. This method argues in favor of expert judgment and qualitative assessment as a decision support tool to the integrative management of estuaries. Namely it allows communicating environmental risk and proposing mitigation measures to local authorities and population under a holistic perspective as an alternative to narrow single line of evidence approaches, which is mandatory to understand cause and effect relationships in complex areas like estuaries.info:eu-repo/semantics/publishedVersio

Viabilidade económica de equipamentos no sector residencial com diferentes etiquetas energéticas

No cenário energético atual, caracterizado pela necessidade de redução da dependência de combustíveis fósseis e da emissão de gases com efeito de estufa, medidas de eficiência energética e a racionalização dos consumos assumem uma importância fulcral [1]. É neste contexto que surgiu a etiquetagem energética de equipamentos do setor residencial, com o intuito de informar os consumidores do desempenho energético dos produtos, permitindo comparar soluções e servindo como instrumento de incentivo a uma redução dos consumos e consequentemente da fatura energética [2]. As mais recentes etiquetas energéticas, uniformes para todos os Estados-Membros da União Europeia, estão desagregadas em classes entre A+++ a D correspondendo a primeira à classificação com melhor desempenho energético e conceção ecológica e a última à menos eficiente [3]. Devido à inovação tecnológica que incorporam, as classes mais eficientes apresentam, tipicamente, investimentos iniciais mais elevados. O objetivo do trabalho é realizar um estudo económico comparativo das classes energéticas A^+,A^(++) e A^(+++) de eletrodomésticos, nomeadamente, frigoríficos, máquinas de lavar roupa e máquinas de lavar louça, de forma a poder consciencializar o consumidor final da relação investimento inicial-eficiência durante o tempo de vida útil do equipamento. Para o efeito, recorreu-se a elementos de análise económica e financeira implementados na ferramenta EXCEL. Os resultados obtidos mostram que dentro das classes energéticas mais eficientes, é preciso ter alguma precaução na escolha feita, e que nem sempre o produto mais eficiente compensa a nível de investimento total relativamente ao número de anos de vida útil do produto.info:eu-repo/semantics/publishedVersio

Gla-rich protein (GRP) as an early and novel marker of vascular calcification and kidney dysfunction in diabetic patients with CKD: a pilot cross-sectional study

Vascular calcification (VC) is one of the strongest predictors of cardiovascular risk in chronic kidney disease (CKD) patients. New diagnostic/prognostic tools are required for early detection of VC allowing interventional strategies. Gla-rich protein (GRP) is a cardiovascular calcification inhibitor, whose clinical utility is here highlighted. The present study explores, for the first time, correlations between levels of GRP in serum with CKD developmental stage, mineral metabolism markers, VC and pulse pressure (PP), in a cohort of 80 diabetic patients with mild to moderate CKD (stages 2-4). Spearman's correlation analysis revealed a positive association of GRP serum levels with estimated glomerular filtration rate (eGFR) and α-Klotho, while a negative correlation with phosphate (P), fibroblast growth factor 23 (FGF-23), vascular calcification score (VCS), PP, calcium (x) phosphate (CaxP) and interleukin 6 (IL-6). Serum GRP levels were found to progressively decrease from stage 2 to stage 4 CKD. Multivariate analysis identified low levels of eGFR and GRP, and high levels of FGF-23 associated with both the VCS and PP. These results indicate an association between GRP, renal dysfunction and CKD-mineral and bone disorder. The relationship between low levels of GRP and vascular calcifications suggests a future, potential utility for GRP as an early marker of vascular damage in CKD.Portuguese Society of Nephrology (SPN) ; Portuguese national funds from FCT-Foundation for Science and Technology through the transitional provision DL57/2016/CP1361/CT0006 UIDB/04326/2020info:eu-repo/semantics/publishedVersio