510 research outputs found

    Fragment-History Volumes

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    Hardware-based triangle rasterization is still the prevalent method for generating images at real-time interactive frame rates. With the availability of a programmable graphics pipeline a large variety of techniques are supported for evaluating lighting and material properties of fragments. However, these techniques are usually restricted to evaluating local lighting and material effects. In addition, view-point changes require the complete processing of scene data to generate appropriate images. Reusing already rendered data in the frame buffer for a given view point by warping for a new viewpoint increases navigation fidelity at the expense of introducing artifacts for fragments previously hidden from the viewer. We present fragment-history volumes (FHV), a rendering technique based on a sparse, discretized representation of a 3d scene that emerges from recording all fragments that pass the rasterization stage in the graphics pipeline. These fragments are stored into per-pixel or per-octant lists for further processing; essentially creating an A-buffer. FHVs using per-octant fragment lists are view independent and allow fast resampling for image generation as well as for using more sophisticated approaches to evaluate material and lighting properties, eventually enabling global-illumination evaluation in the standard graphics pipeline available on current hardware. We show how FHVs are stored on the GPU in several ways, how they are created, and how they can be used for image generation at high rates. We discuss results for different usage scenarios, variations of the technique, and some limitations

    Optimization of raw ewes’ milk high-pressure pre-treatment for improved production of raw milk cheese

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    Serra da Estrela protected designation of origin (PDO) cheese is manufactured with raw milk from Bordaleira and/or Churra Mondegueira da Serra da Estrela sheep breeds. Several socioenvironmental shortcomings have reduced production capacity; hence, treatments that may contribute to its efficient transformation into cheese are welcome. High-pressure processing (HPP) milk pre-treatment may contribute to a cheese yield increment, yet optimization of processing conditions is warranted. An initial wide-scope screening experiment allowed for pinpointing pressure intensity, holding time under pressure and time after HPP as the most important factors influencing curd yield. Based on this, a more targeted screening experiment allowed for selecting the range of experimental conditions to be used for an experimental design study that revealed an HPP treatment at 121 MPa for 30 min as the optimum for milk processing to improve curd yield (>9%) and effectively maintain the beneficial cheese microbiota; the optimum was validated in a final experimental framework.info:eu-repo/semantics/publishedVersio

    Electrochemically gated graphene field-effect transistor for extracellular cell signal recording

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    This work presents an experimental characterization of electrochemically gated graphene field-effect transistors (EGFETs) to measure extracellular cell signals. The performance of the EGFETs was evaluated using cardiomyocytes cells. Extracellular signals with a peak value of 0.4 pico-amperes (pA) embedded in a noise level of 0.1 pA were recorded. Signals in current mode were compared with signals recorded as a voltage. Signals below 28 μV of magnitude can be detected in a noise floor of 7 μV with a signal-to-noise ratio of 4

    Comparing different packaging conditions on quality stability of high-pressure treated Serra da Estrela cheeses during cold storage

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    Serra da Estrela cheese with a Protected Designation of Origin (PDO) is a traditional cheese that is wrapped in paper without vacuum. High-pressure processing (HPP), which requires vacuum packaging of the cheese, has been used for its cold pasteurization to overcome safety issues. In this study, two packaging systems were studied: non-vacuum greaseproof paper wrapping package and vacuum packaging in plastic film. Lactococci, lactobacilli, enterococci, and total mesophiles reached ca. 8 log cfu g−1 and 4–6 log cfu g−1 in control (unpasteurized) and HPP-treated cheeses, respectively, with no significant differences between packaging systems. Spoilage microorganisms' viable cell numbers were reduced to 5 log cfu g−1 in non-vacuum paper-wrapped cheeses. A vacuum-packaging system enabled better control of cheese proteolysis, which was revealed to be closer to that of the original control cheese values at the end of the 10-month storage period. In addition, cheese stored under vacuum film packaging became harder than non-vacuum paper-wrapped cheeses at each time point. Overall, conventional non-vacuum paper wrapping is adequate for short storage periods (<3 months), but for long periods vacuum packaging in plastic film is preferable.info:eu-repo/semantics/publishedVersio

    Lichen xanthones as models for new antifungal agents

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    Due to the emergence of multidrug-resistant pathogenic microorganisms, the search for new antimicrobial compounds plays an important role in current medicinal chemistry research. Inspired by lichen antimicrobial xanthones, a series of novel chlorinated xanthones was prepared using five chlorination methods (Methods A–E) to obtain different patterns of substitution in the xanthone scaffold. All the synthesized compounds were evaluated for their antimicrobial activity. Among them, 3-chloro-4,6-dimethoxy-1-methyl-9H-xanthen-9-one 15 showed promising antibacterial activity against E. faecalis (ATCC 29212 and 29213) and S. aureus ATCC 29213. 2,7-Dichloro-3,4,6-trimethoxy-1-methyl-9H-xanthen-9-one 18 revealed a potent fungistatic and fungicidal activity against dermatophytes clinical strains (T. rubrum, M. canis, and E. floccosum (MIC = 4–8 µg/mL)). Moreover, when evaluated for its synergistic effect for T. rubrum, compound 18 exhibited synergy with fluconazole (ΣFIC = 0.289). These results disclosed new hit xanthones for both antibacterial and antifungal activity.This work was partially supported through national funds provided by FCT/MCTES - Foundation for Science and Technology from the Ministry of Science, Technology, and Higher Education (PIDDAC) and the European Regional Development Fund (ERDF) through the COMPETE - Programa Operacional Factores de Competitividade (POFC) programme, under the Strategic Funding UID/Multi/04423/2013, the projects POCI-01-0145-FEDER-028736 and POCI-01-0145-FEDER-016790 (PTDC/MAR-BIO/4694/2014; 3599-PPCDT) in the framework of the programme PT2020, as well as by the project INNOVMAR - Innovation and Sustainability in the Management and Exploitation of Marine Resources (reference NORTE-01-0145-FEDER-000035, within Research Line NOVELMAR), supported by North Portugal Regional Operational Programme (NORTE 2020), under the PORTUGAL 2020 Partnership Agreement, through the European Regional Development Fund (ERDF). Diana I. S. P. Resende also acknowledge for her grant (NOVELMAR/BPD_2/2016-019) and Patrícia Pereira-Terra for her grant (NOVELMAR/BPD/2017/012)

    Ploidy mosaicism and allele-specific gene expression differences in the allopolyploid Squalius alburnoides

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    <p>Abstract</p> <p>Background</p> <p><it>Squalius alburnoides </it>is an Iberian cyprinid fish resulting from an interspecific hybridisation between <it>Squalius pyrenaicus </it>females (P genome) and males of an unknown <it>Anaecypris hispanica-</it>like species (A genome). <it>S. alburnoides </it>is an allopolyploid hybridogenetic complex, which makes it a likely candidate for ploidy mosaicism occurrence, and is also an interesting model to address questions about gene expression regulation and genomic interactions. Indeed, it was previously suggested that in <it>S. alburnoides </it>triploids (PAA composition) silencing of one of the three alleles (mainly of the P allele) occurs. However, not a whole haplome is inactivated but a more or less random inactivation of alleles varying between individuals and even between organs of the same fish was seen.</p> <p>In this work we intended to correlate expression differences between individuals and/or between organs to the occurrence of mosaicism, evaluating if mosaics could explain previous observations and its impact on the assessment of gene expression patterns.</p> <p>Results</p> <p>To achieve our goal, we developed flow cytometry and cell sorting protocols for this system generating more homogenous cellular and transcriptional samples. With this set-up we detected 10% ploidy mosaicism within the <it>S. alburnoides </it>complex, and determined the allelic expression profiles of ubiquitously expressed genes (<it>rpl8</it>; <it>gapdh </it>and <it>β-actin</it>) in cells from liver and kidney of mosaic and non-mosaic individuals coming from different rivers over a wide geographic range.</p> <p>Conclusions</p> <p>Ploidy mosaicism occurs sporadically within the <it>S. alburnoides </it>complex, but in a frequency significantly higher than reported for other organisms. Moreover, we could exclude the influence of this phenomenon on the detection of variable allelic expression profiles of ubiquitously expressed genes (<it>rpl8</it>; <it>gapdh </it>and <it>β-actin</it>) in cells from liver and kidney of triploid individuals. Finally, we determined that the expression patterns previously detected only in a narrow geographic range is not a local restricted phenomenon but is pervasive in rivers where <it>S. pyrenaicus </it>is sympatric with <it>S. alburnoides</it>.</p> <p>We discuss mechanisms that could lead to the formation of mosaic <it>S. alburnoides </it>and hypothesise about a relaxation of the mechanisms that impose a tight control over mitosis and ploidy control in mixoploids.</p

    O protagonismo do idoso no processo de envelhecimento

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    A velhice como categoria socialmente construída tem sido vista e tratada de maneira diferente, de acordo com períodos históricos e com as estruturas sociais de cada povo (BRUNO, 2003). O fenômeno do envelhecimento no Brasil tem sido caracterizado por uma “revolução demográfica”. Tal situação se torna um problema social tendo em vista que o país não se encontra estruturado para receber o contingente de idosos. O envelhecimento populacional desponta como uma das maiores conquistas da sociedade, mas paradoxalmente como um dos maiores desafios para a agenda contemporânea. Sobretudo, no que tange a democratização da qualidade de vida, mediante a efetivação de direitos de cidadania preconizados pela legislação em vigor em nosso país. O envelhecimento na sociedade brasileira tem se revelado um fenômeno complexo sendo considerado uma das formas de expressão da questão social, uma vez que implica multifacetados problemas que repercutem o campo social, econômico e político na vida dos idosos e na economia do país como causa e consequência. Refletindo no âmbito individual, familiar e social dos idosos, exigindo políticas sociais para o enfrentamento dessa questão social setorial. Na sociedade capitalista o idoso é visto como indivíduo fraco para compor a força de trabalho, que por valores sociais impedem a participação do mesmo em vários cenários da sociedade. O conhecimento da existência de um modelo social geral de velho, presente no imaginário social, que se constrói pela contraposição à identidade de jovem, levou-nos a pensar sobre questões relativas a construção da identidade do idoso. Embora essa problemática suscite reflexões mais delongadas acerca da fragilidade do Estado burguês capitalista em comportar uma sociedade justa e equânime para todas as idades, o ponto central aqui refere-se a questão para a necessidade de construção de uma nova imagem e lugar para a velhice. Nessa perspectiva este estudo tem por objetivo investigar qual é o protagonismo do idoso no processo de envelhecimento
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