690 research outputs found

    Abundance and diversity of soil arthropods in the olive grove ecosystem

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    Arthropods are part of important functional groups in soil food webs. Recognizing these arthropods and understanding their function in the ecosystem as well as when they are active is essential to understanding their roles. In the present work, the abundance and diversity of soil arthropods is examined in olive groves in the northeast region of Portugal during the spring. Five classes of arthropods were found: Chilopoda, Malacostraca, Entognatha, Insecta, and Arachnida. Captures were numerically dominated by Collembola within Entognatha, representing 70.9% of total captures. Arachnida and Insecta classes represented about 20.4 and 9.0%, respectively. Among the predatory arthropods, the most representative groups were Araneae and Opiliones from Arachnida, and Formicidae, Carabidae, and Staphylinidae from Insecta. From the Formicidae family, Tetramorium semilaeve (Andre 1883), Tapinoma nigerrimum (Nylander 1856), and Crematogaster scutellaris (Olivier 1792) were the most representative ant species. Arthropods demonstrated preference during the day, with 74% of the total individuals recovered in this period, although richness and similarity were analogous during the day and night

    Groundnut seedling emergence in relation to thermal-time and soil water

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    A medição do efeito de várias combinações de temperatura e água do solo sobre a emergência do amendoim permite verificar que as curvas de emergência relativamente à acumulação de temperatura são bem descritas por funções logísticas que se interpretam como curvas de probabilidade acumulada. Tais curvas permitem determinar facilmente o tempo-térmico para 50% da emergência final, a dispersão da emergência e a duração-térmica para ocorrência duma emergência de 80% da final. Verifica-se que estes parâmetros são praticamente invariantes (relativamente ao tempo, à temperatura e à água) para teores de água no solo superiores a 45% da capacidade de campo e temperaturas inferiores à óptima para a emergência, pelo que a sua medição pontual é representativa para toda esta gama de condições ambientaisinfo:eu-repo/semantics/publishedVersio

    Transformação de coordenadas cartográficas: o exemplo da região de Granja (NW do Ceará, Brasil)

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    Este estudo tem como principal objetivo mostrar a importância de se efetuar a análise metódica da cartografia de base que suporta a produção de Cartografia Geológica, antes de iniciar o trabalho de campo. Em certas regiões, as cartas base publicadas estão ainda associadas a redes geodésicas clássicas, o que obriga a proceder à transformação de coordenadas para assegurar que todos os dados geo-espaciais são definidos no mesmo sistema de referência espacial. Neste estudo, selecionaram-se 8 pontos localizados sobre as cartas publicadas na região de Granja (NW do Ceará, Brasil), determinaram-se as coordenadas no Datum topocêntrico das cartas (CA 70-72) e procedeu-se à sua transformação para os Data geocêntricos WGS84 e SIRGAS2000. As diferenças entre as coordenadas obtidas nos três sistemas são residuais, indicando que erros introduzidos quando se desconsideram parâmetros essenciais como o Datum Geodésico são, neste caso, mínimos para efeitos de Cartografia Geológica.This study draws attention to the importance of conducting a detailed analysis of cartographic products that sustain the Geological Mapping before starting the field work. In some regions, the published base maps are still related to classical geodetic networks. Therefore, it is fundamental to perform the adequate coordinate transformation to ensure that all spatial data are defined relatively to the same spatial reference system. This is particularly relevant when GPS and GIS are used to obtain and plot spatial data. The present study involved the selection of 8 points located on the published maps for the Granja region (NW Ceará, Brazil), the determination of their coordinates in the CA 70-72 topocentric map Datum and their subsequent transformation to the geocentric Data WGS84 and SIRGAS2000. The differences between coordinates are residual, indicating that the error introduced when essential parameters such as the Geodetic Datum are disregarded are, in this case, minimum

    Application of chemometric tools for the comparison of volatile profile from raw and roasted regional and foreign almond cultivars (Prunus dulcis)

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    In almonds, volatile compounds are major contributors to flavour, being scarce the current knowledge about their volatile profile. Hence, this work intended to characterize the volatile profile, using headspace solidphase microextraction and gas chromatography–mass spectrometry, in raw and roasted almond cultivars (regional cvs. Amendoa˜o, Bonita, Casanova, Molar and Pegarinhos and foreign cvs. Ferragne`s and Glorieta). Overall, 35 compounds were identified, with major chemical classes being alcohols and aldehydes. In raw fruits, benzaldehyde and 3-methyl-1-butanol were key compounds, with roasting changing volatile profiles, increasing release of compounds, with predominance of hexanal and benzaldehyde. Cultivars Glorieta and Molar didn’t show significant increase in aldehyde content after roasting, which may indicate higher resistance to heat-caused oxidation. The use of linear discriminant analysis and principal components analysis permitted the recognition of patterns in the volatile profiles, that can be useful for cultivars identification. This work allowed the characterization and monitoring changes caused by roasting of volatile components of less studied almond cultivars, identifying some that can withstand roasting procedures with reduced formation of compounds associated with off-flavours.Ivo Oliveira is grateful to FCT, POPH-QREN and FSE for the Post-doctoral Fellowship SFRH/BPD/111005/2015. This work is supported by: European Investment Funds by FEDER/ COMPETE/POCI—Operational Competitiveness and Internacionalization Programme, under Project POCI-01-0145-FEDER-006958 and National Funds by FCT—Portuguese Foundation for Science and Technology, under the Project UID/AGR/04033/2013.info:eu-repo/semantics/publishedVersio

    Análise de ciclo de vida do azeite transmontano

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    O sector do azeite é um importante factor económico em Portugal. Sendo Portugal um grande consumidor deste produto, também é um dos principais produtores Europeus (o quarto maior produtor da Europa, atrás da Grécia, Itália e Espanha) e exportadores. A nível nacional, a região de Trás-os-Montes e segundo o Recenseamento Agrícola, é a segunda maior região olivícola, sendo que é a principal a nível de azeitona para a mesa. Numa altura em que a consciencialização ambiental está a ganhar um peso nas escolhas de produtos para o nosso dia-a-dia, é cada vez mais importante haver uma produção “amiga do ambiente”. É neste ponto em que entra a chamada Análise de Ciclo de Vida (ACV). A ACV é um estudo assente num sistema de modelação com todos os componentes necessários para a produção de um determinado bem, fazendo de seguida uma avaliação aos impactes causados no ambiente. Este teve como ponto de partida inquéritos aplicados a três produtores de azeitonas (F1, F2 e F3) e a dois lagares de azeite (P2 e P3), tendo estas actividades características diferenciadas. O F1 é um olival de tamanho mediano (~12ha), com uma prática agrícola considerada normal. Relativamente ao F2, este é considerado um olival de grande tamanho (mais de 100ha), com uma prática agrícola também considerada normal. O F3 também é um olival de grande tamanho (mais de 100ha), mas é praticado uma agricultura biológica. Nos lagares, a grande diferença é o modo utilizado para a extracção do azeite, sendo que o P2 é de duas fases e o P3 é de três fases. Para uma correta análise, foi seguido a metodologia referida nas ISO’s 14040 e 14044 e a parametrização referida na última versão do Environmental Product Declaration (EPD). Os resultados obtidos resultam da avaliação de diferentes interacções entre o olival e o lagar, obtendo-se um total de seis cenários com diferentes resultados, expressos na intensidade de indicadores de avaliação de impacto (mid-points).info:eu-repo/semantics/publishedVersio

    Influence of temperature and soil moisture on leaf area and dry matter accumulation during establishment of pea, maize and sunflower

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    Leaf area expansion and accumulation of dry matter during the establishment of pea(Pisum sativum L., var. Ballet), maize (Zea mays L., var. Lorena) and sunflower (Helianthus annuus L., var. Florasol) were studied at different temperatures and soil moisture contents in a Vertisol (Lisboa) and a Luvisol (Évora) from June 1995 to November 1996. Measurements were made of soil temperature at 2 and 4 cm depth, air temperature and soil water content. Leaf area per plant was estimated from measurements of the length and width of each leaf. Above ground seedling dry matter was weighed after oven drying. Data analysis was based on the thermal time concept. For water contents above 50% of the available capacity of each soil, leaf area of pea and maize increased linearly with accumulated temperature while that of sunflower increased exponentially. Dry matter of all crops increased exponentially with accumulated temperature. Significant differences between the two types of soil were found on the “initiation of leaf area expansion” of pea and sunflower, on the “thermal-rate for leaf area expansion” of maize and on the dry matter accumulation of pea and maize seedlings. The “initiation of leaf expansion” of pea occurred earlier in soil Cb while that of sunflower occurred earlier in soil Pmg. Leaf area expansion of maize was faster in soil Pmg. Dry matter accumulation of pea was faster in soil Cb while that of sunflower was faster in soilPmg. In both soils, low soil water contents reduced leaf area expansion and dry matter accumulation of the crops

    Influence of the day period on the abundance and diversity of soil arthropods in olive grove ecosystem.

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    On soil food webs, arthropods are part of important functional groups. Recognize these arthropods and understand its function in the ecosystem as well as the period of the day in which they are actives, is essential to understand their roles. In the present work we intend to study the soil arthropods diversity as well as the period of the day that are actives in three olive groves from the Northeast of Portugal. Particular emphasis was given to the generalist predators that can attack olive fruit fly pupae in soil. The work was carried out during the spring of 2006 and at a bi-weekly basis 25 pitfall traps/grove were put during 12 hours both on day period (from 7:00am to 7:00pm) and on night period (from 7:00 pm to 7:00 am). The collected individuals were sorted and identified. Five classes of arthropods were found: Chilopoda, Malacostraca, Entognatha, Insecta and Arachnida. Captures were numerically dominated by springtails. Arachnida and Insecta classes represented about 20.4% and 9.0% respectively from the total captures. Among the predatory arthropods, the most representative groups were Aranea and Opiliones from arachnids and Formicidae, Carabidae and Staphylinidae from insects. On Formicidae, Tetramorium semilaeve Andre 1883, Tapinoma nigerrimum (Nylander 1856) and Crematogaster scutellaris (Olivier, 1792) were the most representative ant species. Arthropods have demonstrated preference for the day, with 74% of the total individuals recovered in this period although richness and similarity have been similar between periods

    Antioxidant activity of indigenous yeasts isolated during the fermentation of table olives from Northeast of Portugal

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    Yeasts have an important role in fermented foods, including table olives. These microorganisms can be a new source of natural antioxidants. Free-radical-scavenging antioxidants have potential as protective agents against various degenerative diseases caused by oxidative damage. In the present study, antioxidant activity of indigenous yeasts isolated during the natural fermentation of table olives (Negrinha Freixo cv.) was evaluated. These strains were previously identified by rDNA sequences of the ITS region. The antioxidant activity was performed by the percentage of reduction of the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical. The studied strains are included in the genera Saccharomyces, Candida, Pichia, Debaryomyces, Rhodotorula and Galactomyces. Saccharomyces boulardii was included as probiotic reference strain. All strains showed distinct antioxidant activity. The ability to scavenge DPPH radical indicated that S. cerevisiae isolated from table olives may be a promising candidate strain for use as probiotics with antioxidant activity.info:eu-repo/semantics/publishedVersio
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