Padrões geográficos de diversidade genética da abelha melífera em Portugal (continente e ilhas)

A Europa alberga três linhagens evolutivas da abelha melífera (Apis mellifera L.), nomeadamente: linhagem M (oeste e norte europeia), linhagem C (sudeste Europeia) e linhagem A (Africana). A linhagem C inclui mais de 6 subespécies destacando-se, pela sua importância na apicultura mundial, a A. m. ligustica (abelha italiana) e A. m. carnica (abelha carniola). Por sua vez, a linhagem M agrupa apenas a A. m. mellifera (abelha preta) e A. im. iberiensis (abelha ibérica). Enquanto a distribuição natural da abelha preta inclui uma boa parte das regiões da Europa Ocidental e Central até à Península Escandinava, Alemanha e Polónia, a abelha ibérica está confinada à Península Ibérica. Porém, é nesta região da Europa que a abelha melífera exibe maior diversidade genética, resultante da coexistência de abelhas de origem Europeia (M) e Africana (A). Num contexto de profundas alterações ambientais (e.g. alterações climáticas, poluição, pesticidas, novos patogénios e parasitas), a preservação deste valioso património é crucial pois a sobrevivência a longo prazo de qualquer organismo depende da sua diversidade genética

Generalized fractional maxwell model : parameter estimation of a viscoelastic material

In this paper, we show how fractional viscoelastic models can be efficient in the modeling of linear viscoelastic behavior, increasing the fitting accuracy of classic generalized viscoelastic models, such as the Generalized Maxwell model. Experimental data (Loss and Storage modulus in the frequency domain) were retrieved from a Dynamic Mechanical Analysis test considering Carbon Fibre Reinforced Polymer samples. The estimated parameters, for the derived fractional viscoelastic models, were obtained through numerical optimization techniques that minimize the difference between model-predicted values and experimental data. An excellent correlation between analytical and experimental results was observed, minimizing numerical instabilities found on a previous work, for the same experimental setup.This work was financed by FEDER funds through COMPETE-Programa Operacional Fatores de Competitividade and by portuguese funds through FCT-Fundação para a Ciência e a Tecnologia within projects PEst-C/MAT/UI0013/ 2011

Parameter estimation of viscoelastic materials : a test case with different optimization strategies

In this work, and based on numerical optimization techniques, constitutive parameters for viscoelastic materials are determined using a inverse problem formulation. The optimization methodology is based on experimental results obtained in the frequency domain, for a CFRP-Carbon Fibre Reinforced Polymer, through DMA-Dynamic Mechanical Analysis. The relaxation modulus of viscoelastic materials is given by a summation of decaying exponentiating functions, known as Prony series. Prony series, in time domain, are normally used to determine constitutive parameters for viscoelastic materials. In this paper, using the Fourier transform of the time domain Prony series, a nonlinear constrained least square problem based on Prony series representations of storage and loss modulus, for the considered material, is analyzed. A case study considering the estimation of 2N viscoelastic parameters, N = 1,2, ···11, is taken as a benchmark. The nonlinear constrained least square problems are solved using global and local optimization solvers. The computational results as well as the main conclusion are shown

A modified fractional zener model to describe the behaviour of a carbon fibre reinforced polymer

In this work a modified conventional Fractional Zener Model is deduced and applied to estimate the viscoelastic constitutive parameters of a Carbon Fibre Reinforced Polymer. The accuracy of this modified model was studied against conventional Fractional Zener model and Fractional Maxwell model, considering experimental data in the frequency domain. The set of parameters was found by solving a nonlinear constrained least square problem based on the variation of the storage and loss moduli with frequency.This work was financed by FEDER funds through COMPETE (Operational Programme Thematic Factors of Competitiveness) and by portuguese funds through FCT (Foundation for Science and Technology) within the project PEst-C/MAT/UI0013/ 2011

Olive oil sensory analysis as a tool to preserve and valorize the heritage of centenarian olive trees

In inland areas of Portugal and some regions of the Mediterranean basin, olive production is based on traditional olive groves, with low intensification, local cultivars, aged plants, and centenarian trees. These plants play a key role in the ecosystem, contributing to carbon sequestration and possessing a high genetic diversity, particularly important for selecting cultivars more resistant to climatic changes. Appreciation of the value of this genetic diversity implies genetic, morphological, and physicochemical characterization of centenarian trees, which is expensive and time-consuming. Sensory evaluation is also of utmost importance. Thus, in this study, centenarian olive trees were selected in the Côa Valley region, a UNESCO World Heritage site. The descriptive sensory profile of their extracted olive oils was established and used to cluster the oils, using hierarchical clustering analysis, and consequently the olive trees, into five groups with similar intensities of perceived olfactory–gustatory attributes. Each cluster revealed olive oils with unique sensory patterns, presumably due to similarities of the olive trees, confirming the potential of the proposed screening approach. The identification of sensorially homogeneous oil-tree groups would reduce the number of specimens needed for subsequent morphological, genetic, and chemical characterization, allowing a cost-effective and robust future evaluation procedure.The authors are grateful to the Foundation for Science and Technology (FCT, Portugal) for financial support from national funds FCT/MCTES to CIMO (UIDB/00690/2020) and SusTEC (LA/P/0007/2020). This work was also supported by the FCT project OLIVECOA-Centenarian olive trees of Coa Valley region: rediscovering the past to valorize the future, ref. COA/BRB/0035/2019. Nuno Rodrigues was funded by FCT-Foundation for Science and Technology, P.I., through the institutional scientific employment program-contract.info:eu-repo/semantics/publishedVersio

Bioactive properties of the medicinal mushroom Leucopaxillus giganteus mycelium obtained in the presence of different nitrogen sources

Leucopaxillus mushroom species are used in the chemical industry for extraction of clitocybin antibiotic and particularly the edible mushroom Leucopaxillus giganteus can be found in Northeast Portugal. Nevertheless, the production of its mycelium for pharmacological applications has not been explored. Herein, the mycelium obtained in the presence of four different nitrogen sources was investigated with regard to phenol production and antimicrobial and antioxidant properties. Phenol concentration increased along the growth time as a response to the oxidative stress and therefore free radical production. Although significant differences for mycelium growth between the nitrogen sources had not been observed, (NH4)2HPO4 proved to be the most appropriate to increase bioactive properties, leading to the highest phenol content and lowest EC50 and MIC values. The antimicrobial capacity was screened against Gram positive and Gram negative bacteria, and fungi. The samples selectively inhibited the growth of Gram positive bacteria, Staphylococcus aureus being the most susceptible one. Gram negative bacteria and fungi were resistant to the extracts. Antioxidant activity was calculated by the reducing power assay, the scavenging effect on DPPH radicals, and hemolysis and lipid peroxidation inhibition. Significantly negative linear regressions were established between phenols/flavonoids contents, which increased along the mycelia growth time and antioxidant activity

Diversidade da comunidade de fungos endofíticos em Quercus suber em diferentes cenários climáticos

Cork oak (Quercus suber L.) is an evergreen oak tree species, typically found throughout the Mediterranean Basin, which presents a great ecological and economic importance for Portugal. An increase of cork oak decline due to biotic and abiotic stresses has been reported, which could damage the ecosystem and lower cork production. The attack of some fungal pathogens seems to increase when trees are under several environmental stresses, such as increased temperatures or drought. In this work, fungal endophytic species of cork oak were collected from forest stands in different sites of Portugal. The community of fungal endophytes of young and old twigs was studied by obtaining fungal isolates from plant material and grouping them into morphotypes. This study allowed the comparison of fungal endophytic communities living in cork oak trees from different forests, displaying distinct climates and water availability levels. The results revealed that endophyte communities are better discriminated when considering different plant tissues than cork oak stand location or climate.O sobreiro (Quercus suber L.) é uma espécie arbórea de folha perene, encontrada tipicamente na Bacia do Mediterrâneo, que apresenta uma elevada importância ecológica e económica para Portugal. Um aumento no declínio do sobreiro tem sido associado a situações de stresse biótico e abiótico, o qual resulta em danos no ecossistema e diminuição da produção de cortiça. A infeção por fungos patogénicos parece aumentar quando os sobreiros se encontram sob condições ambientais promotoras de stresse, como temperatura elevada e secura. Neste trabalho, as espécies fúngicas endófitas de sobreiro foram colhidas a partir de exemplares em diferentes locais de Portugal. A comunidade de fungos endófitos de ramos com diferentes idades foi estudada pela obtenção de isolados a partir deste material vegetal, e pelo agrupamento dos isolados em morfótipos. Este estudo permitiu a comparação das comunidades fúngicas endófitas em diferentes povoamentos florestais, sujeitos a condições climáticas distintas e a diferentes níveis de disponibilidade de água. Os resultados revelam que as comunidades endófitas são distintas entre os diferentes tecidos vegetais, sendo mais semelhantes entre os locais das florestas ou clima.This work was supported by the European Regional Development Fund (ERDF), through the Operational Programme for Competitiveness and Internationalization (COMPETE 2020), under Portugal 2020, and by the Fundação para a Ciência e a Tecnologia – FCT (National Agency for Science and Technology) through national funds in the framework of the project POCI-01-0145-FEDER-026365, and national funds by FCT under the projects PEst-OE/BIA/UI4046/2014 and UID/MULTI/04046/2013. D. Costa thanks FCT for PhD grant SFRH/BD/120516/2016

Phenolic profile and antioxidative properties of the beefsteak fungus Fistulina hepatica

The phenolic composition of the edible beefsteak fungus Fistulina hepatica was determined by HPLC/DAD. The results showed a profile composed by caffeic, p-coumaric and ellagic acids, hyperoside and quercetin. Ellagic acid was the main compound in this species. Beefsteak fungus was also investigated for its capacity to act as a scavenger of DPPH radical and reactive oxygen species (superoxide radical, hydroxyl radical and hypochlorous acid). Good results were obtained against DPPH and superoxide radicals and hypochlorous acid but a prooxidant effect was observed for hydroxyl radical

Interaction between two co-occurring fungi present in chestnut orchards

Hypholoma fasciculare is a wood-decaying basidiomycete with a worldwide distribution, including tropical, temperate and boreal forest ecosystems. In Trás-os-Montes region (Northeast of Portugal) this species is commonly present in soils of several habitats, including chestnut and oak tree forests. The ectomycorrhizal fungus Pisolithus tinctorius is another species with high occurrence in those ecosystems. The present work intends to study the in vitro interaction between H. fasciculare and P. tinctorius through evaluation of fungal growth, changes on hyphae morphology, the production of volatile compounds and Iytic enzymes. The results obtained showed that H. fasciculare inhibited significantly the growth of P. tinctorius in 49%, long before hyphal contact of their colonies. This inhibition could be result from the liberation from H. fasciculare of volatile compounds and/or diffusible inhibitory substances, such as extracellular enzymes. Alteration in the production of volatile compounds, distributed in several chemical classes (alcohols, ketones, aldehydes, terpenes, among others) was detected over the time course of interaction. In addition, amylase, cellulase, laccase and lipase were produced by H. fasciculare. The possible role of these compounds during interaction will be discussed.This work is supported by FCT I&D grant PTDC/ AGR-AAM/099556/200

Seeking for sensory differentiated olive oils? The urge to preserve old autochthonous olive cultivars

Mediterranean olive heritage richness is poorly characterized. Olive oils from minor cultivars of Northeast- Portugal (Lentisca, Madural, Rebolã, Redondal, Verdeal and Verdeal Transmontana) from centenarian trees were chemical and sensory characterized, aiming to identify autochthonous cultivars capable of producing differentiated olive oils. All oils, produced during two campaigns, were classified as extra virgin. Cv. Redondal showed the highest oxidative stability (OS), total phenols, vitamin E and C18:1/C18:2. Contrary, cv. Madural presented the lowest OS and C18:1/C18:2 ratios, supporting the importance of fatty acids on OS, while cv. Verdeal had the lowest total phenols and vitamin E contents. Sensory notes of tomato, apple, dry fruits, fresh herbs, tomato leaves and cabbage were predominant on the oils of most cultivars, whilst some attributes were more specific, such as banana and kiwi (Madural), cherry and apricot (cvs. Lentisca and Madural). The chemical and sensory diversity enabled the statistical discrimination of all cultivars and harvesting years.This work was financially supported by Strategic Project PEst-OE/ AGR/UI0690/2019 (CIMO), Project UID/QUI/50006/2013 (REQUIMTE-LAQV); and Project POCI-01-0145-FEDER-006984 (Associate Laboratory LSRE-LCM); all funded by Fundo Europeu de Desenvolvimento Regional (FEDER) through COMPETE2020-Programa Operacional Competitividade e Internacionalização (POCI) and by national funds through Fundação para a Ciência e a Tecnologia (FCT), Portugal. This work was also supported by PRODER project OliveOld – Identificação e caraterização de oliveiras centenárias para obtenção de produtos diferenciados” n° 53988. Nuno Rodrigues thanks FCT, POPHQREN and FSE for the Ph.D. Grant (SFRH/BD/104038/2014).info:eu-repo/semantics/publishedVersio