1,020 research outputs found

    Prediction of overwash in alongshore variable barrier islands [Previsão da ocorrência de galgamentos em ilhas barreira com variabilidade longilitoral]

    Get PDF
    Overwash prediction is very important for coastal zone management. This work intends to identify alongshore variations in storm impact and evaluate the role of sub-aerial and submerged morphologies in overwash occurrence. For this study, 24 cross-shore topo-bathymetric profiles were set on Barreta Island (Ria Formosa barrier island system, Portugal). Pre- and post-overwash surveys were made between August 2012 and April 2013. During overwash events, tidal levels and wave parameters at breaking were obtained. Overwash occurred under storm and non-storm conditions, the latter coincident with spring high-tide. Beach morphology was spatially variable, and changeable from one overwash episode to the next. Predictions of overwash occurrence were made using the Overwash Potential, defined as the difference between runup and barrier elevation. Several runup equations were tested, and the results compared to the actual observations. The selected predictor provided an accuracy of 88% for the identification of the locations where overwash occurred. This study proves that nearshore and foreshore morphologies have a major impact on the longshore distribution of overwash.info:eu-repo/semantics/publishedVersio

    A simplified protocol for Agrobacterium-mediated transformation of cell suspension cultures of the model species Medicago truncatula A17

    Get PDF
    Funding Information: Open access funding provided by FCT|FCCN (b-on). This work was supported by Fundação para a Ciência e Tecnologia (FCT, Portugal) through Research Units “Molecular, Structural and Cellular Microbiology” (MOSTMICRO, UIDB/ 04612/2020) and “Bioresources 4 Sustainability” (GREEN-IT, UIDB/04551/2020). Publisher Copyright: © 2023, The Author(s).This manuscript describes a unique protocol for the rapid transformation of Medicago truncatula A17 cell suspension cultures mediated by Agrobacterium tumefaciens. Medicago cells were collected on day 7 of the growth curve, which corresponded to the beginning of the exponential phase. They were then co-cultured with Agrobacterium for 3 days before being spread onto a petri dish with appropriate antibiotic selection. The Receptor Binding Domain of the Spike protein of SARS-CoV-2 was used as a model to develop this protocol. The presence of the transgene was assessed using PCR, and the integrity of the product was evaluated by SDS-PAGE and Western-blotting.publishersversionpublishe

    Chemiomics: network reconstruction and kinetics of Port Wine aging

    Get PDF
    Network reconstruction (NR) has proven to be useful in the detection and visualization of relationships among the compounds present in a Port wine aging data set. This view of the data provides a considerable amount of information with which to understand the kinetic contexts of the molecules represented by peaks in each chromatogram. The aim of this study was to use NR together with the determination of kinetic parameters to extract more information about the mechanisms involved in Port wine aging. The volatile compounds present in samples of Port wines spanning 128 years in age were measured with the use of GC-MS. After chromatogram alignment, a peak matrix was created, and all peak vectors were compared to one another to determine their Pearson correlations over time. A correlation network was created and filtered on the basis of the resulting correlation values. Some nodes in the network were further studied in experiments on Port wines stored under different conditions of oxygen and temperature in order to determine their kinetic parameters. The resulting network can be divided into three main branches. The first branch is related to compounds that do not directly correlate to age, the second branch contains compounds affected by temperature, and the third branch contains compounds associated with oxygen. Compounds clustered in the same branch of the network have similar expression patterns over time as well as the same kinetic order, thus are likely to be dependent on the same technological parameters. Network construction and visualization provides more information with which to understand the probable kinetic contexts of the molecules represented by peaks in each chromatogram. The approach described here is a powerful tool for the study of mechanisms and kinetics in complex systems and should aid in the understanding and monitoring of wine quality.info:eu-repo/semantics/acceptedVersio

    Coloração vital com azul de metileno aplicada a tripomastigotas e epimastigotas de Trypanosoma cruzi

    Get PDF
    The morphological identification of Trypanosoma cruzi is currently considered to have a high specificity, but its sensitivity, which depends on the volume of the sample examined, is rather low. Trypanosome developmental stages suspended in blood, reduviid feces, and culture media are routinely searched for by means of fresh film examination (about 2 µL). High speed centrifugation of blood samples separates the buffy coat, where most trypomastigotes concentrate. As the parasites are transparent and colorless, their detection is mostly dependent on their motility. The fluorescent vital stain acridine orange has been used to enhance image contrast, as exemplified by the QBC (Quantitative Buffy Coat) technique. Staining blood, buffy coat, reduviid feces, and culture media samples with methylene blue (also a vital dye) is a means of producing sharp, well contrasted images of motile or non-motile T. cruzi developmental stages, only standard laboratory microscopes being required. Slides previously coated with a thin layer of methylene blue are used to stain fresh blood films. Photomicrographs exemplify the results of methylene blue staining applied to living and fixed parasites.A identificação morfológica de Trypanosoma cruzi tem alta especificidade, segundo é geralmente aceito; entretanto, sua sensibilidade, dependente do volume da amostra examinada, é baixa. Formas evolutivas de T. cruzi suspensas em sangue, fezes de reduviídeos e meios de cultura são rotineiramente pesquisadas em esfregaços a fresco (cerca de 2 µL). Centrifugação de amostras de sangue a altas velocidades produz a separação do creme leucocitário, onde se concentram as formas tripomastigotas. Em preparações a fresco, a motilidade das formas tripomastigotas e epimastigotas de T. cruzi, protozoário transparente e incolor, facilita sua detecção. Laranja de acridina, corante vital fluorescente, tem sido usada para acentuar o contraste das imagens de parasitas. Disto é exemplo a técnica QBC (Quantitative Buffy Coat). A coloração por meio de azul de metileno (também um corante vital), de amostras de sangue, de fezes de reduviídeos ou de meios de cultura permite obter imagens nítidas e contrastadas de formas evolutivas de T. cruzi com ou sem motilidade. Microscópios de uso geral em laboratórios permitem o exame dos parasitas corados. Uma camada bem delgada de azul de metileno colocada sobre a parte central da lâmina limpa (por meio da evaporação de solução diluída do corante) é usada para corar as preparações a fresco. O aspecto dos parasitas corados em materiais frescos ou previamente fixados pode ser observado em fotomicrografias

    Automatic determination of yeast cells viability by image analysis

    Get PDF

    Bioactive properties of Mentha spicata L. infusions: a comparison between standard and reserve lots

    Get PDF
    Mentha spicata L., commonly known as spearmint and belonging to the Lamiaceae family, is widely used as infusion due to its exquisite and outstanding flavour [1]. This medicinal and aromatic plant is also known for its antioxidant properties due to naturally occurring active compounds, such as phenolic compounds including flavonoids. [2] Recently, with the increased consumption of herbal infusions, several novel products are emerging and different lots with distinct compositions of the same plant are available for herbal infusions preparation [3]. As an outstanding example, the standard lots have evolved to "reserve lots", which are prepared from the apical leaves of the plant, presenting different compositions and sensorial characteristics. In the present study, the aim was to evaluate and compare the antioxidant activity as well as the bioactive compounds (phenolics and flavonoids) content of M. spicatae infusions prepared from standard and reserve lots, in order to understand the potential differences between both batches. The antioxidant activity was assessed by different assays (free radicals scavenging activity, reducing power, and lipid peroxidation inhibition), whereas total phenolics and flavonoids were estimated by colorimetric assays. The best results of antioxidant activity were achieved with the reserve lot that presented the lowest EC50o values in all the assays performed (152 to 336 μg/mL) in comparison to the standard lot (173 to 546 μg/mL). Both the infusions revealed higher potential in lipid peroxidation inhibition, in concentrations of 173 (standard tot) and 152 μg/mL (reserve lot), followed by reducing power (301 and 198 μg/mL, respectively) and free radicals scavenging activity (546 and 336 μg/mL). As expected from the antioxidant assays results, the amounts of total phenolics and flavonoids were higher in the reserve lot (2. 86 and 0. 378 mg GAE/mL, respectively) when compared to the standard lot (1. 83 and 0.268 mg GAE/mL), which is in accordance with the well-known bioactivity of these compounds. Thus, in our perspective, this study represents a major contribution of scientific information, allowing the consumer to understand the increased benefits of these new emerging tea products

    Deciphering a multi-event in a non-complex set of detrital zircon U-Pb ages from Carboniferous graywackes of SW Iberia

    Get PDF
    The determination of U–Pb ages from detrital zircons of sedimentary rocks using LA-ICP-MS has been widely used for the purpose of provenance analysis. One problem that frequently arises is finding a population that appears to be non-complex despite several perceptible age peaks in its spectrum. These peaks are qualitatively defined by means of relative probability diagrams, or PDFs, but it is difficult to quantify their statistical significance relative to a zircon forming multi-event. Thus, can a multi-event in a non-complex set of detrital zircon U–Pb ages be deciphered and characterized? The aim of this study is to attempt to provide an answer to this question by means of statistical analysis. Its objectives are: a) to determine the best minimum number of zircon age populations (peaks), BmPs, b) for the characterization of each peak in terms of age and event duration; c) to compare the results obtained from two datasets showing similar zircon ages; and d) to demonstrate the usefulness of deciphering these BmPs. First, cluster analysis is carried out, aimed at grouping zircon ages into a set of consistent clusters. A Gaussian Kernel function is then fitted to each cluster and summed to obtain a theoretical PDFm (modeled probability density function). Finally, the selected modeled PDFm (that built on the BmPs) is that which reports the lowest number of peaks for which the difference as compared with the original gPDF (global probability density function) is equal to or below 5%. Deciphered BmP peaks can be characterized and used for characterizing and providing an understanding of related event(s). A geological interpretation, based on the results obtained, is attempted. This includes a robust measure for maximum age of deposition for both Cabrela and Mértola graywackes
    corecore