Silvopastoral agroforestry for rural environment sustainability and valorization of the region of Guarda and Serra da Estrela, Portugal

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AFINET: agroforestry innovation thematic network

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Carbon storage in the soil under different land uses in the south of Portugal

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Marine organism sulfated polysaccharides exhibiting significant antimalarial activity and inhibition of red blood cell invasion by Plasmodium

The antimalarial activity of heparin, against which there are no resistances known, has not been therapeutically exploited due to its potent anticoagulating activity. Here, we have explored the antiplasmodial capacity of heparin-like sulfated polysaccharides from the sea cucumbers Ludwigothurea grisea and Isostichopus badionotus, from the red alga Botryocladia occidentalis, and from the marine sponge Desmapsamma anchorata. In vitro experiments demonstrated for most compounds significant inhibition of Plasmodium falciparum growth at low-anticoagulant concentrations. This activity was found to operate through inhibition of erythrocyte invasion by Plasmodium, likely mediated by a coating of the parasite similar to that observed for heparin. In vivo four-day suppressive tests showed that several of the sulfated polysaccharides improved the survival of Plasmodium yoelii-infected mice. In one animal treated with I. badionotus fucan parasitemia was reduced from 10.4% to undetectable levels, and Western blot analysis revealed the presence of antibodies against P. yoelii antigens in its plasma. The retarded invasion mediated by sulfated polysaccharides, and the ensuing prolonged exposure of Plasmodium to the immune system, can be explored for the design of new therapeutic approaches against malaria where heparin-related polysaccharides of low anticoagulating activity could play a dual role as drugs and as potentiators of immune responses

An Individual Tree Growth Model for Juvenile Cork Oak Stands in Southern Portugal

Abstract. The juvenile and adult stages in cork oak are distinct because of the periodic debarking of the stem and branches that characterizes the adult stage. This fact implies the use of diameter under bark for the adult stage while diameter over bark is the natural variable for juvenile stands in growth and yield studies. Tree growth in the adult stage may also be affected by the periodic debarking. The differences between the two stages justify the development of different models for each of them. The objective of this paper is to develop an individual tree growth and yield model for juvenile cork oak stands for general application on the cork oak distribution area in Southern Portugal. The most important modules of this growth model were developed using data collected from a large number of trees in the juvenile stage, from several plots distributed around the South of Portugal. These modules were: an individual tree diameter growth model, a height-diameter model and a model for crown diameter prediction. Key words: Quercus suber L.; growth and yield model Modelo de Crescimento para Árvores em Povoamentos Juvenis de Sobreiro em Portugal Sumário. A fase juvenil e adulta no sobreiro distinguem-se entre si pela existência de descortiçamentos periódicos no fuste e nas pernadas ao longo da fase adulta. Este facto obriga ao uso do diâmetro sem cortiça na fase adulta, enquanto o diâmetro com cortiça é a variável natural em estudos de crescimento e produção realizados em povoamentos jovens. As diferenças entre as duas fases justificam o desenvolvimento de diferentes modelos para cada uma. O objectivo deste trabalho é desenvolver um modelo de crescimento e produção da árvore individual para povoamentos juvenis de sobreiro, para aplicação geral na área de distribuição do sobreiro em Portugal. Os módulos mais importantes deste modelo de crescimento foram desenvolvidos com dados recolhidos num grande número de árvores em fase juvenil, de um conjunto de parcelas distribuídas pelo Sul de Portugal. Estes módulos são: um modelo de crescimento em diâmetro para a árvore, uma curva hipsométrica e um modelo para a predição do diâmetro da copa. Palavras-chave: Quercus suber L.; modelo de crescimento e produção des arbres adultes on mesure le diamètre sur liège, alors que sur des arbres jeunes la variable mesurée est naturellement le diamètre sous liège. Cette différence oblige au développement d'un modèle de croissance et production spécifique pour les arbres jeunes. Ce modèle est l'objectif de cette étude et comprend des équations pour la modélisation de la croissance en diamètre de l'arbre et de sa cime et une courbe hypsométrique. Les données ont été relevées sur des jeunes arbres dans plusieurs parcelles de l'aire d'expansion de l'espèce dans le sud du Portugal

Trends in the control of hexapod robots: a survey

The static stability of hexapods motivates their design for tasks in which stable locomotion is required, such as navigation across complex environments. This task is of high interest due to the possibility of replacing human beings in exploration, surveillance and rescue missions. For this application, the control system must adapt the actuation of the limbs according to their surroundings to ensure that the hexapod does not tumble during locomotion. The most traditional approach considers their limbs as robotic manipulators and relies on mechanical models to actuate them. However, the increasing interest in model-free models for the control of these systems has led to the design of novel solutions. Through a systematic literature review, this paper intends to overview the trends in this field of research and determine in which stage the design of autonomous and adaptable controllers for hexapods is.The first author received funding through a doctoral scholarship from the Portuguese Foundation for Science and Technology (FCT) (Grant No. SFRH/BD/145818/2019), with funds from the Portuguese Ministry of Science, Technology and Higher Education and the European Social Fund through the Programa Operacional Regional Norte. This work has been supported by the FCT national funds, under the national support to R&D units grant, through the reference project UIDB/04436/2020 and UIDP/04436/2020

Hexapod posture control for navigation across complex environments

Hexapod locomotion in unstructured environments relies on an efficient posture adjustment with the terrain topology. This paper presents a strategy to adapt the hexapod torso orientation through ground plane estimation. With an Inertial Measurement Unit (IMU) and the robot kinematic model, the current supporting feet coordinates are calculated, and the relative inclination between the ground and the torso angular position can be obtained. This information is used to adjust the novel foothold positions, in order to ensure the hexapod posture remains stable. The torso height is also controlled to avoid collisions with the ground asperities and decrease its deviation during motion. The proposed method is evaluated in a complex terrain made of 0.1×0.1 m blocks with variable height, causing different slopes across the field. Through result analysis, a significant behavior improvement is observed, due to the reduction of the torso posture oscillation and the increase of its locomotion efficiency.The first author received funding through a doctoral scholarship from the Portuguese Foundation for Science and Technology (FCT) (Grant No. SFRH/BD/145818/2019), with funds from the Portuguese Ministry of Science, Technology and Higher Education and the European Social Fund through the Programa Operacional Regional Norte. This work has been supported by FCT within the R&D Units Project Scope: UIDB/00319/2020, UIDB/04436/2020 and UIDP/04436/2020

Predicting site index from climate and soil variables for cork oak (Quercus suber L.) stands in Portugal

Comunicação OralN/

First records of Tarentola mauritanica (Linnaeus, 1758) (Reptilia; Gekkonidae) in the Azores

The Moorish gecko Tarentola mauritanica (Linnaeus, 1758) is a widespread species native to the Mediterranean region from southern France to Greece and northern Africa (Loveridge 1947; Martínez-Rica 1997; Hódar 2002; Perera et al. 2008, 2010; Plezeguelos et al. 2008). It has recently been reported as living and breeding in California (Marhdt 1998) and also as an introduced species in Madeira (Báez & Biscoito 1993). Tarentola mauritanica is paraphyletic with respect to T. angustimentalis Steindachner, 1891, a Canary Islands endemic (Harris et al. 2004a). Here we report new occurrences of the Moorish gecko on Terceira Island, Azores archipelago, and 3 other occurrences on the islands of São Miguel and Faial. The possibility of an already established breeding population is discussed

Bioactive hydrolysates from chlorella vulgaris: optimal process and bioactive properties

Microalgae have been described as a source of bioactive compounds, such as peptides. Microalgae are easy to produce, making them a sustainable resource for extracting active ingredients for industrial applications. Several microalgae species have interesting protein content, such as Chlorella vulgaris with around 52.2% of protein, making it promising for peptide hydrolysate production. Therefore, this work focused on the production of water-soluble hydrolysates rich in proteins/peptides from the microalgae C. vulgaris and studied bioactive properties. For that, a design of experiments (DOE) was performed to establish the optimal conditions to produce hydrolysates with higher levels of protein, as well as antioxidant and antihypertensive properties. Four experimental factors were considered (cellulase percentage, protease percentage, hydrolysis temperature, and hydrolysis duration) for three responses (protein content, antioxidant activity, and antihypertensive activity). The optimal conditions determined by the DOE allowed producing a scaled-up hydrolysate with 45% protein, with antioxidant activity, measured by oxygen radical absorbance capacity assay, of 1035 µmol TE/g protein, IC50 for angiotensin-converting enzyme inhibition activity of 286 µg protein/mL, and α-glucosidase inhibition of 31% (30 mg hydrolysate/mL). The obtained hydrolysates can be used as functional ingredients for food and nutraceuticals due to their antioxidant, antihypertensive, and antidiabetic potential. Moreover, the antioxidant potential of the extracts may be relevant for the cosmetic industry, especially in antiaging formulations.info:eu-repo/semantics/publishedVersio