2,482 research outputs found

    A serologia para avaliação do papel dos predadores em olival biológico

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    A oliveira, sendo uma planta mediterrânica, encontra-se bem adaptada em Portugal. Apesar de ser uma cultura com poucos problemas fitossanitários, por vezes e sujeita à acção de algumas pragas e doenças. De entre as pragas de artrópodos destacam-se a traça da oliveira, Prays oleae (Bern.), a mosca da azeitona, Bactrocera oleae (GmeL) e a cochonilha negra, Saissetia oleae (Oliv.). No entanto, as populações destes inimigos podem ser mantidas abaixo do nível económico de ataque por factores abióticos e/ou por outros artrópodos, espécies predadoras e parasitóides, que contribuem para a estabilidade da biocenose no olival A valorização destes auxiliaras é, assim, um factor preponderante na protecção contra pragas da oliveira, nomeadamente em modo de produção biológico

    Produção de antissoros policlonais para detecção de predadores das principais pragas da oliveira

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    A oliveira está bem adaptada às áreas mediterrâneas mas por vezes é sujeita à acção de inimigos, nomeadamente a traça da oliveira, Prays oleae (Bern.), a mosca da azeitona, Bactrocera oleae (Gmel.) e a cochonilha negra, Saissetia oleae (Oliv.). No entanto, as populações destes inimigos podem ser mantidas abaixo do nível económico de ataque por factores abióticos e bióticos. Entre estes incluem-se espécies predadoras e parasitóides que contribuem para a estabilidade da biocenose. A valorização dos auxiliares artrópodos é, assim, factor preponderante na protecção contra pragas da oliveira, nomeadamente em modo de produção biológico. A utilização de técnicas serológicas, particularmente ELISA (enzyme linked immunosorbent assay), para avaliação da predação em artrópodos, já é bastante utilizada. Para futuramente se avaliar o papel dos predadores em olivais conduzidos de acordo com o modo de produção biológico, em Trás-os-Montes e no Alentejo, produziram-se antissoros policlonais para monitorizar as três pragas nos seus principais predadores. Este trabalho refere a preparação dos antigénios, o protocolo de imunização dos coelhos, a colheita dos antissoros e sua caracterização preliminar por ELISA

    Differentiation of production method and geographical origin of salmon based on the analysis of fatty acid composition

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    Currently, aquaculture production supplies almost 50% of the global fish market, as a response to the increasing global demand for fish [1]. However, several consumers prefer wild over farmed fish, with the former generally attaining higher prices when the some species is considered. Therefore, there is the need to assure correct information, not only about the species, but also about the production method (farmed vs. wild) and the catch origin of fish. Salmon, a high-trophic - level carnivorous species with high economic value due to its popularity, is among the fish species that is frequently produced in aquoculture. Although the feed given to farm-raised salmon is designed to meet its nutritional requirements, it can present differences compared to the diet of wild salmon that con be reflected on the muscle composition of formed versus wild solmons. Therefore, in this work, the use of fatty acid composition combined with chemometrics was evaluated as a potential tool to authenticate salmon samples. In particular, the work aimed at identifying the geographical origin and production method (farmed vs. caught in the wild) of salmon.info:eu-repo/semantics/publishedVersio

    Los moluscos del cesped algal intermareale en Azores

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    The molluscan fauna of the high intertidal algal turf on the island of Pico (Azores) was studied in order to complement existing descriptions of the intertidal biota on these islands. A total of 15,275 specimens belonging to 19 species were found. Five species, the gastropods Alvania mediolittoralis Gofas, 1989, Omalogyra atomus (Philippi, 1841), Pisinna glabrata (Megerle von Muhlfeld, 1824) and Skeneopsis planorbis (Fabricius 0., 1780), and the bivalve Lasaea adansoni (Gmelin, 1791), account for 98% of the total number of specimens, P. glabrata itself being responsible for 46% of all specimens. In places where patellid limpets are absent, Ihe algal turf extends higher in the intertidal zone. In such places, three very abundant molluscan species characterize molluscan assemblages in the algal turf: Lasaea adansoni, Skeneopsis planorbis and Pisinna glabrata, Lasaeo adansoni and Skeneopsis planorbis virtually disappear in the transition from algal lurf to algal fronds, the only (very) abundant species being P. glabrata and, with less importance, Omalogyra atomus and Sinezona cingulata (Costa O.G., 1861)

    Synthesis and characterization of novel thieno[3,2-b]thiophene based metal-free organic dyes with different heteroaromatic donor moieties as sensitizers for dye-sensitized solar cells

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    Four novel heterocycle dyes 3a-d were synthesized in order to study the variations produced in the optical, electronic and photovoltaic properties by substitution of different electron-rich heterocyclic groups to the thieno[3,2-b]thiophene system. The final push-pull conjugated dyes 3a-d were synthesized by Suzuki-Miyaura coupling reaction followed by Knoevenagel condensation of the corresponding aldehyde precursors with cyanoacrylic acid 2a-d. These new push-pull systems are based on a thieno[3,2-b]thiophene spacer, a cyanoacetic acid anchoring group and several electron-rich heterocycles (thiophene, pyrrole and furan) as donor groups. The multidisciplinary study concerning the optical, redox and photovoltaic characterization of the dyes reveals that compound 3b bearing a hexyl-bithiophene donor group/heterocyclic spacer exhibits the best overall conversion efficiency (2.49%) as sensitizer in nanocrystalline TiO2 dye sensitized solar cells. Co-adsorption studies between N719 and 3b revealed that upon addition of N719 co-adsorbent, the optimized cell efficiencies were improved by 16–77%. The best efficiency was 4.40%, corresponding to 54% of the photovoltaic performance of the N719-based DSSC fabricated and measured under similar conditions.FCTFEDERQRENEuropean Research Council (Contract no: 321315

    Central Auditory Processing Outcome After Stroke In Children.

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    To investigate central auditory processing in children with unilateral stroke and to verify whether the hemisphere affected by the lesion influenced auditory competence. 23 children (13 male) between 7 and 16 years old were evaluated through speech-in-noise tests (auditory closure); dichotic digit test and staggered spondaic word test (selective attention); pitch pattern and duration pattern sequence tests (temporal processing) and their results were compared with control children. Auditory competence was established according to the performance in auditory analysis ability. Was verified similar performance between groups in auditory closure ability and pronounced deficits in selective attention and temporal processing abilities. Most children with stroke showed an impaired auditory ability in a moderate degree. Children with stroke showed deficits in auditory processing and the degree of impairment was not related to the hemisphere affected by the lesion.72680-

    Pathogens in ornamental waters: a follow up study

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    Ornamental waters of easy access and populated with animals are quite attractive and can hide threats to human health. Here we evaluated the microbiota of ornamental waters in a Lisbon park. Water and biofilm samples where collected, in 2 lakes (L1-L2) and ornamental fountains (L3-L4) in February/2015. In May/2015 and monthly during a year (starting March/2016) samples from L4 where collected. Microbiota identification was performed as described previouslya. Biofilm assembly was monitored by crystal violet assay and SEMb and antibiotic susceptibility was performed by conventional methods. The results of the first water sampling (Feb/2015) revealed the presence of Enterobactereaceae and non-fermentative oxidase-positive bacteria. Fountains and lakes presented different microbota being the highest diversity found in L1 hosting a duck population. This result suggested the existence of an interplay between animal inhabitants and microbiota which was confirmed by the second sampling of L4 (May/2015). Between the 2 sampling events a fish population was introduced and the microbiota was completely altered with the appearance of a typical fish pathogen (Aeromonas spp). This tendency was also confirmed over 2016. K. pneumoniae and Aeromonas spp., present as planktonic and biofilm organized bacteria in 2015 showed an enhanced ability to assemble biofilms in vitro at 25 °C than at 37 °C. Bacteria recovered from biofilm showed an increased antibiotic resistance compared to planktonic counterparts. The pilot study conducted during 2015 and the follow up study (still in progress) support a periodic control of ornamental water microbiota as simple preventive measure to avoid potential health issues.Fundação para a Ciência e Tecnologia for the grant PEst-OE/CTM/UI0084/2011N/
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