Mercado da energia eléctrica: uma modelação MPCC-NLP

O problema apresentado está relacionado com o mercado de energia eléctrica, modelado como um jogo de Stackelberg, onde a empresa líder de mercado tem o poder de manipular os preços e a capacidade de produção, de forma a maximizar o seu lucro. Devido às suas características particulares, o problema foi formulado como um Problema de Optimização com Restrições de Complementaridade (MPCC) e, posteriormente reestruturado num Problema de Programação Não Linear (NLP), com o intuito de tirar partido das suas propriedades, utilizando software específico

A MPCC-NLP approach for an electric power market problem

The electric power market is changing - it has passed from a regulated market, where the government of each country had the control of prices, to a deregulated market economy. Each company competes in order to get more clients and maximize its profits. This market is represented by a Stackelberg game with two firms, leader and follower, and the leader anticipates the reaction of the follower. The problem is formulated as a Mathematical Program with Complementarity Constraints (MPCC). It is shown that the constraint qualifications usually assumed to prove convergence of standard algorithms fail to hold for MPCC. To circumvent this, a reformulation for a nonlinear problem (NLP) is proposed. Numerical tests using the NEOS server platform are presented

Systematic review of the effects of coffee or its components on platelets and their regulators

Coffee includes some potentially bioactive components that can interfere with platelets, which can influence coagulation, despite generating controversy. The aim of this systematic review is to verify whether coffee or its components can influence platelet regulators and/or aggregation. Materials and Methods: The research was conducted on July 29, 2021, in PubMed, Scopus, andWeb of Science, using the followingmesh-terms: (caffeine)) OR (coffee)) AND (platelets). Eligibility criteria were: studies carried out in humans, referring to the effects of coffee consumption, or one of its components, on platelets or their regulators. We exclude in vitro or animal studies, reviews, editorials, and non-English written studies. From a total of 836 publications, 17 articles were included from which we extracted the relationship between coffee consumption and changes in blood platelets and performed a subjective assessment of bias. Results: Ten articles refer to the non-interference of coffee or its components with platelets, nine affirm results that support the increase in platelet aggregation, and eight articles observe the decrease in platelet aggregation when coffee is consumed. Some articles presented the lack of data regarding the sample collection location, age group, or classification as to the type of study, which is limiting. Conclusions: The heterogeneity of results makes it difficult to correctly interpret the possible interaction of coffee or its components with platelets or their regulators. For better interpretation, further studies on this topic should be carried out considering the individualization of coffee components, different platelet regulators, and the size of the sample used.The Centro de Investigac¸a˜o de Montanha (CIMO) received financial support from Fundac¸a˜o para Ciencia e a Tecnologia (FCT, Portugal) and from Fundo Europeu de Desenvolvimento Regional (FEDER), under PT2020 program (UIDB/00690/2020).info:eu-repo/semantics/publishedVersio

Perceptions of Public Officers Towards the Effects of Climate Change on Ecosystem Services: A Case-Study From Northern Portugal

ASV was supported by the Ministerio de Ciencia, Innovación y Universidades (Spain) through the 2018 Juan de la Cierva-Formación program (contract reference FJC2018-038131-I) and the FCT—Foundation for Science and Technology through Stimulus of Scientific Employment, Individual support (reference 2020.01175.CEECIND). JRV was supported as a post-doc researcher at ICETA CIBIO/InBIO by the national funds through FCT—Foundation for Science and Technology, DL57/2016/ICETA/EEC2018/13. CC-S was supported by the “Contrato-Programa” UIDP/04050/2020 funded by national funds through the Fundação para a Ciência e Tecnologia I.P.We thank Cristiana Manuela Barros and Manuela Alves for their help on the organization of the workshops.All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.How institutional stakeholders perceive the supply and demand of ecosystem services (ES) under distinct contexts determines which planning actions are deemed priority or not. Public officers play a crucial role in social-ecological management and decision-making processes, but there is a paucity of research exploring their perceptions on ES supply and demand under a changing climate. We address this gap through an exploratory study that analyses the views of public officers on the potential impacts of climate-change related drivers on multiple ES in a major administrative region from Portugal (EU NUTS 3). We combined qualitative spatial data from participatory maps and semi-quantitative answers from questionnaire-based surveys with 22 officers from public institutions contributing to territorial planning. Contrary to other similar studies, public officers shared a common view on the importance of ES. This view aligns with scientific projections on how a changing climate is expected to influence ES in the region over the next decade. In agreement with other observations in Mediterranean regions, the most perceivably valued ES concerned tangible socio-economic benefits (e.g., periurban agriculture and wine production). Surprisingly, despite the region's potential for cultural ES, and considering the impacts that climate change may hold on them, recreation and tourism did not seem to be embedded in the officers' views. We explore the implications of our findings for territorial planning and social-ecological adaptation, considering that the way stakeholders manage the territory in response to climate change depends on the extent to which they are aware and expect to experience climatic consequences in the future.Ministerio de Ciencia, Innovacion y Universidades (Spain) FJC2018-038131IPortuguese Foundation for Science and Technology 2020.01175.CEECIND- DL57/2016/ICETA/EEC2018/13Fundacao para a Ciencia e Tecnologia I.P. UIDP/04050/202

Development of a metric of aquatic invertebrates for volunteers (MAIV): a simple and friendly biotic metric to assess ecological quality of streams

Citizen science activities, involving local people in volunteer-supported and sustainable monitoring programs, are common. In this context, the objective of the present work was to develop a simple Metric of Aquatic Invertebrates for Volunteers (MAIV), including a user-friendly tool that can be easily accessed by volunteers, and to evaluate the e ciency of a volunteer monitoring program following an audit procedure. To obtain MAIV values, macroinvertebrate communities were reduced to 18 surrogate taxa, which represented an acceptable compromise between simplicity, e ciency, and reproducibility of the data, compared to the regular Water Framework Directive monitoring. When compared to results obtained with the National Classification System of Portugal, MAIV accurately detected moderate, poor, and bad ecological status. Thus, MAIV can be used by volunteers as a complement to the o cial monitoring program, as well as a prospective early warning tool for local problems related to ecological quality. Volunteers were students supervised by their teachers. Results obtained by volunteers were compared to results obtained by experts on macroinvertebrate identification to measure the e ciency of the procedure, by counting gains and losses on sorting, and identification. Characteristics of groups of volunteers (age and school level) did not influence significantly the e ciency of the procedure, and generally results of volunteers and experts matched.info:eu-repo/semantics/publishedVersio

A MPCC approach on a Stackelberg game in an electric power market : changing the leadership

An electric power market is studied as a Stackelberg game where two firms, A and B, produce energy. It is analyzed two distinct situations, according to the firm who plays the leader role: the first one, when the firm A is the leader and the other firm is the follower, and the second that is the reverse of the players roles. The main goal is to understand the behavior of the various agents that compose the electric power network, such as transmissions capacity, quantities of power generated and demanded, when changing leadership. The problem is formulated as a Mathematical Program with Complementarity Constraints (MPCC) and reformulated into a Nonlinear Program (NLP), allowing the use of robust NLP solvers. Numerical results are presented and some final considerations are carried out.Universidade do Minho. Centro AlgoritmiFundação para a Ciência e a Tecnologia (FCT

Qualidade do sono e marcadores endócrinos e bioquímicos

O sono e o repouso constituem o ritmo biológico base da espécie humana e são fundamentais para uma boa saúde e qualidade de vida, com especial significado em crianças e jovens (DGS, 2015). Dormir bem é fundamental para a recuperação física e psíquica do indivíduo, indispensável para sermos saudáveis e essencial para nos mantermos ativos, concentrados e bem-dispostos. O sono é um equilibrador do humor e das emoções, recupera o corpo e a memória, estimula a criatividade e aumenta e consolida a capacidade de aprendizagem (Paiva & Penzel, 2011; SPN, 2015). Há cada vez mais evidências de que o sono tem influencia sobre os hábitos alimentares e consequentemente sobre o balanço energético e a regulação do peso corporal, estando também associado a outros fatores de risco metabólico na adolescência (Quist, Sjödin, Chaput & Hjorth, 2016). A má qualidade do sono tem um impacto negativo na qualidade de vida, verificando-se que a privação do sono é um fator de risco relevante para a saúde e segurança, aumentando o risco de doenças cardiovasculares, hipertensão, obesidade, diabetes, depressão, ansiedade e outros distúrbios de humor. A intervenção é fundamental, promovendo bons hábitos de sono desde a infância (Rebelo-Pinto, Pinto, Rebelo-Pinto & Paiva, 2014).info:eu-repo/semantics/publishedVersio

Sleep quality and food intake of high school students

Poor sleep quality is associated with increased food intake and poor diet quality [1]. People with lack of sleep show a positive correlation. between free time and food intake and also experience hormonal and brain changes that drive the intake of food with high calorific value [1-3]. In addition, scientific research has shown a healthy and balanced diet to positively influence the quality of sleep [1]. Objective The present study was set out to assess the sleep quality of high school students in Bragança county, and its association with food intake. Methods The study used non-experimental, analytical and transversal methodology, of epidemiological character and with a quantitative approach. It was intended to carry out the study in a population of 862 high school students. However, due to consent being required from both legal guardians and students, a smaller sample of 345 students was obtained. The data was collected in May 2017 through a questionnaire that included the Pittsburgh Sleep Quality Index (PSQI), validated for the Portuguese population. Results Throughout the study and following PSQI analysis, it was concluded that 39.71% (n = 137) of participants showed poor quality of sleep (PSQI > 5 points). The correlation between sleep quality and food intake was assessed and a statistically significant association was found between the quality of sleep and the intake of snacks (X2 = 17.144; p = 0.000), sugary products (X2 = 18.603; p= 0 .000), fast-food (X2 = 12.353; p = 0.002) and ready meals (X2 = 14.852; p = 0.000). The risk of suffering from poor sleep quality is higher in young populations who frequently eat snacks ([OR]: 2.811; 99%), sugary products ([OR]: 1.901; 95%), fast-food ([OR]: 4.000; 99%) and ready meals ([OR]: 5.621; 95%) in comparison with young populations who rarely eat this sort of food. The sleep quality is also significantly related with the number of meals young people have in a day (X2 = 7.580; p = 0.023). The risk of having poor quality sleep is 2.240 times higher in young people who rarely eat 4-6 meals a day. Conclusions A correlation between sleep quality and food intake in the sampled students was seen. The risk of having poor quality of sleep is higher in students who frequently eat a high calorie diet and also in students who rarely have 4-6 meals a day. There are several connections between sleep quality and eating habits. Sleep promotion and its connection with standard diets should be included as an essential part of community empowerment for health-promoting lifestyles [1,4,5].info:eu-repo/semantics/publishedVersio

Using the ‘regime shift' concept in addressing social-ecological change : Social-ecological regime shifts

‘Regime shift’ has emerged as a key concept in the environmental sciences. The concept has roots in complexity science and its ecological applications, and is increasingly applied to intertwined social and ecological phenomena. Yet what exactly is a regime shift? We explore this question at three nested levels. First, we propose a broad, contingent, multi-perspective epistemological basis for the concept, seeking to build bridges between its complexity theory origins and critiques from science studies, political ecology, and environmental history. Second, we define the concept in a way that is consistent with this epistemology, building on previous work on speed, scale, stickiness, and interrelationships, but also emphasising human perceptions and rhetorical uses of the notion. Third, we propose a novel typology of the ways in which the regime shift concept is used in analysing social–environmental phenomena in geography and beyond. These uses are categorised along two axes. On the one side, we distinguish between description of past or present changes and normative prescriptions for the future. On the other side, we distinguish between whether the focus is on material shifts (social and ecological) or conceptual shifts (discourses and ideas). We illustrate the typology with reference to social–environmental changes in landscapes around the world that are dominated by plantations or the widespread naturalisation of Australian Acacia species. We conclude that the regime shift concept is a boundary object with value as both an analytical and communicative tool in addressing social–environmental challenges

The use of the EUROHIS-QOL-8 to assess the perception of quality of life at Termas de Chaves

Quality of life is a person's perception of life in the context they belong in. It compresses multiple dimensions that need to be assessed. The EUROHIS-QOL-8 scale is an instrument that measures the subjective well-being of individuals and the impact of different health issues. It is a brief tool to measure the quality of life that includes eight items. The higher the results shown in this scale, the better the quality of life of individuals. The EUROHIS-QOL-8 has been proven to have good internal consistency and an excellent index for measuring the quality of life. It has been validated and reliable in many different contexts of application. This paper uses EUROHIS-QOL-8 to evaluate thermalists' perception of quality of life before and after attending a thermal spa. It intends to identify if there are differences between the state of quality of life before and after using thermal spa services. For this purpose, a self-administrated questionnaire was applied to the Termas de Chaves' users during the 2021 thermal season, i.e., between 09 August and 20 December. A convenience method of non-probability sampling allowed to obtain a sample of 213 thermal users. The data were analysed through statistical techniques of exploratory descriptive and inferential analysis. The results showed statistically significant differences in customers' perception of quality of life before and after 14 days of treatment. In addition, the study of five sociodemographic variables showed that the categories: female, up to 35 years old, single, without academic qualifications, and housekeeper were the most benefited from the thermal treatments. Regarding the analysis of pathologies, the participants guided by their family doctor to attend the Chaves thermal springs for respiratory problems showed the most significant improvement. The paper's results dissemination becomes an added value for verifying the benefits of thermal spas on the individuals' quality of life. It also allows for better development of thermal spa products to improve the quality of life perceived by individuals.info:eu-repo/semantics/publishedVersio