Seasonal photosynthesis, respiration, and calcification of a temperate Maërl bed in southern Portugal

Rhodolith (maerl) beds are biodiversity hotspots with a worldwide distribution. Maerl is the general term for free-living non-geniculate rhodoliths or coralline red algae. In southern Portugal, maerl beds are mainly composed of Phymatolithon lusitanicum, recently identified as a new species and commonly misidentified as Phymatolithon calcareum. Photosynthesis, respiration, and growth rates of the algae were measured seasonally, as well as the photosynthetic pigment composition. To characterize the seasonal and interannual patterns of key abiotic conditions in the largest described maerl bed of the Portuguese coast, temperature, irradiance, and dissolved oxygen were continuously monitored over a 2-year period. At the bed depth (22 m), temperature ranged between 14 degrees C in winter and 24 degrees C in summer, irradiance varied from 5 to 75 mu.mol m(-2) s(-1) , and dissolved oxygen from 5.8 to 7.25 mg O-2 L-1. We found a strong linear relationship (r(2) = 0.95) between gross primary production (GPP) and relative electron transport rates (rETRs). Both methods led to similar results and an average molar ratio of 0.24. Photosynthesis and respiration increased in summer and decreased in autumn and winter. In the summer of 2013, the growth rates were twofold higher (1.34 mu.mol CaCO3 g(-1) day(-1)) than in the other seasons. In winter and spring, to compensate for light deprivation and low temperature, algae increased their chlorophyll a and carotenoid concentrations while also decreasing their phycobilin concentration, in this case probably due to nutrient limitation. To isolate the role of temperature on the algae's metabolism, the photosynthetic and respiration rates of individual thalli were measured at eight different temperatures in the laboratory (from 12 degrees C to 26 degrees C). Phymatolithon lusitanicum photosynthesis increased twofold after a threshold of 18 degrees C (from 2.2 at 18 degrees C to 3.87 mu mol O-2 m(-2) s(-1) at 20 degrees C), whereas respiration increased fourfold with temperature after a threshold of 22 degrees C (from -0.38 at 18 degrees C to -1.81 (mu mol O-2 m(-2) s(-1) at 24 degrees C). The significant increases on respiration, photosynthetic rates, and maximum growth with temperature reveal that the metabolic rates of P. lusitanicum are highly sensitive to ocean warming.UIDB/04326/2020info:eu-repo/semantics/publishedVersio

Oxidative stress and quantum yield efficiency in the intertidal seagrass zostera noltii

We investigated the combined effects of several environmental stressors in the photosynthetic performance and in the activation of biochemical defense mechanisms in the intertidal seagrass Zostera noltii in Ria Formosa coastal lagoon (southern Portugal). The maximum (Fv/Fm) and the effective (F’v/F’m) quantum use efficiencies of PSII were sampled monthly in both neap and spring tides over one year. Other fluorescence parameters, such as the Stern-Volmer non-photochemical quenching (NPQ) and the novel parameter LNP (which expresses the general decrease in PSII photochemical activity in the light) were derived from quantum use efficiency measurements. Sampling for antioxidant enzymes activity, pigments, soluble protein and malondialdehyde (MDA) was conducted in parallel. Reactive oxygen species (ROS) are formed as a normal part of the metabolism. An increment on ROS formation is a common response to those stresses and can cause several types of damage, namely lipid peroxidation. MDA is a product of the peroxidation of membrane lipids and thus is commonly used as an indicator of oxidative stress. Carotenoids and antioxidant enzymes such as ascorbate peroxidase (APx) are part of the plants’ antioxidative system. Higher content of carotenoids indicate a higher photoprotection and increased activities of ROS scavenging enzymes such as APx are correlated with stress tolerance. The relationships among critical environmental parameters (irradiance, temperature, air exposure), oxidative stress, antioxidative responses and quantum use efficiency in Z. noltii were explored through multifactorial analysis

Remoção de metais pesados por biofilmes suportados em carvão activado

Instituto de Biotecnologia e Química Fina (IBQF)

Remoção de metais pesados por biofilmes suportados em carvão activado

Instituto de Biotecnologia e Química Fina (IBQF)

Teaching accounting and management through business simulation:

Everyday accounting and management teachers face the challenge of creating learning environments that motivate students. This chapter describes the Business Simulation (BS) experience that has taken place at the Polytechnic Institute of Porto, Institute of Accounting and Administration (IPP/ISCAP). The chapter presents students’ perceptions about the course and the teaching/learning approach. The results show that pedagogical methods used (competency-oriented), generic competencies (cooperation and group work), and interpersonal skills (organisational and communication skills) are relevant for future accounting professionals. In addition, positive remarks and possible constraints based on observation, staff meetings, and past research are reported. The chapter concludes with some recommendations from the project implementation

Accounting education in an action-based learning environment: lessons learned

In the context of the Bologna Declaration a change is taking place in the teaching/learning paradigm. From teaching-centered education, which emphasizes the acquisition and transmission of knowledge, we now speak of learning-centered education, which is more demanding for students. This paradigm promotes a continuum of lifelong learning, where the individual needs to be able to handle knowledge, to select what is appropriate for a particular context, to learn permanently and to understand how to learn in new and rapidly changing situations. One attempt to face these challenges has been the experience of ISCAP regarding the teaching/learning of accounting in the course Managerial Simulation. This paper describes the process of teaching, learning and assessment in an action-based learning environment. After a brief general framework that focuses on education objectives, we report the strengths and limitations of this teaching/learning tool. We conclude with some lessons from the implementation of the project

Ecophysiological Studies on Cistus Palhinhae Ingram and Cistus Ladanifer L. in Southern Alentejo

Cistus palhinhae Ingram is an endemic plant from Portugal, with a non-consensual taxonomical position. Some authors consider it as a variety or sub-specie of C. ladanifer L.. Until now, the knowledge about C. palhinhae is limited, so we pretend to compare ecophysiologically and anatomically both species in the same area. The study was performed in 3 sampling sessions in Cape Sardão region, where the two species occur. Plant cover structure, water potential and leaf area index were assessed. According to our results, ecophysiological processes are different between the studied species, especially the ones associated with the xeric features: C. palhinhae possesses marked xeromorphic adaptations, differing from C. ladanifer a semi-deciduos sclerophyll shrub

Modelação computacional do membro inferior humano para a reprodução da dinâmica da marcha com músculos: casos saudável e patológico

Dissertação de mestrado integrado em Engenharia BiomédicaA biomecânica do movimento compreende o estudo e análise do movimento realizado por seres vivos, quer seja para melhorar o seu desempenho ou prevenir e tratar lesões. O primeiro é amplamente aplicado ao estudo do desporto e ao auxílio prestado aos atletas para desempenhar um movimento pretendido. De modo a ajudar na prevenção e tratamento de lesões, a biomecânica visa providenciar conhecimento acerca das propriedades mecânicas dos tecidos humanos, das cargas mecânicas a que eles estão sujeitos durante o movimento e de terapias relacionadas com prevenção e reabilitação. Atua no sentido de auxiliar na projeção estratégias de reabilitação e dispositivos médicos de assistência. Este trabalho compreende o uso de um modelo biomecânico do membro inferior humano previamente desenvolvido por Geyer & Herr (2010). O modelo inclui a reprodução dos sistemas esquelético, muscular e neuronal humanos com o objetivo de produzir o movimento do modelo. Esta abordagem foi utilizada para estudar eventos que ocorrem a nível articular, considerando, por exemplo, a amplitude de movimento e os torques produzidos, durante uma marcha fisiológica e patológica com lesão do ligamento anterior cruzado (LAC). Esta patologia está associada a atividades, tais como o basquetebol, envolvendo mudanças rápidas na direção combinadas com aceleração e desaceleração do corpo. Estas ações causam lesões do LAC e por vezes levam à sua rutura, provocando a necessidade de procedimentos de reabilitação e cirúrgicos para melhorar a qualidade de vida dos pacientes. Para o modelo biomecânico saudável, considerando os ângulos das juntas, os resultados apresentam uma concordância muito boa com a literatura. Os dados cinéticos demonstram algumas semelhanças, bem como discrepâncias. O torque da articulação do tornozelo é o que mais se aproxima da literatura, enquanto que o torque da anca e do joelho apresentam diferenças tanto em magnitude (maior do que o esperado), como em forma. Os padrões de ativação muscular também apresentam diferenças quando comparados com a literatura. Sugestões são dadas para minimizar estas ocorrências. A implementação da patologia consistiu na diminuição do torque produzido pelos músculos (quadríceps e hamstrings) afetados pela lesão do ligamento anterior cruzado após reconstrução cirúrgica. A variável mais próxima da literatura é a força vertical de reação com o solo, enquanto que os restantes dados cinéticos diferem. Sugestões são dadas de forma a equivaler mais os resultados com a literatura.Biomechanics of movement comprises the study and analysis of the movement performed by living beings, whether by improving its performance or by preventing and treating injury. The former is extensively applied to understanding sports and to help athletes performing a desired movement. In order to help preventing and treating injury, biomechanics aims at providing knowledge on the mechanical properties of human tissues, the mechanical loads they feel during movement, and on therapies related to prevention and rehabilitation. It acts to help design rehabilitation procedures and assistive medical devices. This work comprises the use of a biomechanical model of the human lower limb previously developed by Geyer & Herr (2010). The model possesses the reproduction of the human skeletal, muscular and neural systems in order to produce the model’s movement. This approach was used to study the events occurring at joint level, regarding, for instance, its range of motion and produced torques, during physiological and anterior cruciate ligament (ACL) pathological gait. This gait pathology is associated with activities, such as basketball, involving rapid changes in direction combined with acceleration and deceleration of the body. These actions cause ACL injuries and sometimes lead to its rupture, provoking the need for surgical and rehabilitation procedures to improve the patient’s life quality. For the healthy biomechanical model, regarding the joints’ angles, the results present very good agreement with results found in literature. The kinetic data show some similarities, as well as discrepancies. The ankle joint torque is the closest to literature findings, whilst the hip and knee joint torque present differences both in magnitude (higher than expected) and in shape. The muscular activation patterns also present differences when compared to literature. Suggestions are made in order to minimize these occurrences. The implementation of pathology consisted in diminishing the torque produced by the muscles (quadriceps and hamstrings) affected by an anterior cruciate ligament injury after its surgical reconstruction. The variable closer to literature findings is the vertical ground reaction force, whilst the other kinetic and kinematic data differ. Suggestions are made in order to make the results more equivalent to literature