The brushstroke and materials of Amadeo de Souza-Cardoso combined in an authentication tool

Nowadays, authentication studies for paintings require a multidisciplinary approach, based on the contribution of visual features analysis but also on characterizations of materials and techniques. Moreover, it is important that the assessment of the authorship of a painting is supported by technical studies of a selected number of original artworks that cover the entire career of an artist. This dissertation is concerned about the work of modernist painter Amadeo de Souza-Cardoso. It is divided in three parts. In the first part, we propose a tool based on image processing that combines information obtained by brushstroke and materials analysis. The resulting tool provides qualitative and quantitative evaluation of the authorship of the paintings; the quantitative element is particularly relevant, as it could be crucial in solving authorship controversies, such as judicial disputes. The brushstroke analysis was performed by combining two algorithms for feature detection, namely Gabor filter and Scale Invariant Feature Transform. Thanks to this combination (and to the use of the Bag-of-Features model), the proposed method shows an accuracy higher than 90% in distinguishing between images of Amadeo’s paintings and images of artworks by other contemporary artists. For the molecular analysis, we implemented a semi-automatic system that uses hyperspectral imaging and elemental analysis. The system provides as output an image that depicts the mapping of the pigments present, together with the areas made using materials not coherent with Amadeo’s palette, if any. This visual output is a simple and effective way of assessing the results of the system. The tool proposed based on the combination of brushstroke and molecular information was tested in twelve paintings obtaining promising results. The second part of the thesis presents a systematic study of four selected paintings made by Amadeo in 1917. Although untitled, three of these paintings are commonly known as BRUT, Entrada and Coty; they are considered as his most successful and genuine works. The materials and techniques of these artworks have never been studied before. The paintings were studied with a multi-analytical approach using micro-Energy Dispersive X-ray Fluorescence spectroscopy, micro-Infrared and Raman Spectroscopy, micro-Spectrofluorimetry and Scanning Electron Microscopy. The characterization of Amadeo’s materials and techniques used on his last paintings, as well as the investigation of some of the conservation problems that affect these paintings, is essential to enrich the knowledge on this artist. Moreover, the study of the materials in the four paintings reveals commonalities between the paintings BRUT and Entrada. This observation is supported also by the analysis of the elements present in a photograph of a collage (conserved at the Art Library of the Calouste Gulbenkian Foundation), the only remaining evidence of a supposed maquete of these paintings. The final part of the thesis describes the application of the image processing tools developed in the first part of the thesis on a set of case studies; this experience demonstrates the potential of the tool to support painting analysis and authentication studies. The brushstroke analysis was used as additional analysis on the evaluation process of four paintings attributed to Amadeo, and the system based on hyperspectral analysis was applied on the painting dated 1917. The case studies therefore serve as a bridge between the first two parts of the dissertation

Atividades antifúngica, citotóxica (células tumorais humanas) e hemolítica de cumarinas naturais e semi-sintéticas

Dissertação (mestrado) - Universidade Federal de Santa Catarina. Programa de Pós-Graduação em Biotecnologia.As atividades antifúngica, citotóxica e hemolítica de 40 cumarinas foram avaliadas frente às espécies fúngicas: Candida albicans, Aspergillus fumigatus e Fusarium solani, três linhagens de células tumorais humanas: Caco-2 (adenocarcinoma colo retal), HCT-8 (adenocarcinoma ileocecal) e HEp-2 (carcinoma epidermóide de laringe) e eritrócitos humanos do grupo sangüíneo "O" Rh positivo. Entre os compostos cumarínicos estudados, encontram-se as cumarinas simples (monossubstituídas, dissubstituídas e trissubstituídas), as cumarinas preniladas, as furano e piranocumarinas. Para cada uma destas cumarinas foram determinadas as concentrações inibitórias mínimas (CIM) pelo método de microdiluição em caldo, a CC50, ou seja, a concentração de cada amostra que reduziu em 50% a viabilidade celular, pelo ensaio colorimétrico com sal de tetrazolium (MTT) e a porcentagem de hemólise. Os resultados foram expressos em mM. As atividades antifúngica, citotóxica e hemolítica das cumarinas monossubstituídas estudadas não dependeram dos padrões de substituição no núcleo cumarínico, nem mesmo das características dos grupos substituintes. Entre as cumarinas monossubstituídas, a 6-nitrocumarina evidenciou a melhor atividade antifúngica, com CIM de 0,65 mM para Fusarium solani; em relação à atividade citotóxica destacou-se, dentre as cumarinas monossubstituídas, a 6-hidroxicumarina inibindo o crescimento da linhagem celular HCT-8 (CC50: 0,58 mM). As cumarinas di e trissubstituídas não apresentaram atividades antifúngica, citotóxica e hemolítica relevantes. O ostenol foi a cumarina que apresentou a melhor atividade antifúngica dentre todos os compostos testados, com CIM de 0,54 mM para Fusarium solani e 1,08 mM para Candida albicans e Aspergillus fumigatus. A piranocumarina 3a,a di-metil-xantiletina demonstrou a atividade citotóxica mais expressiva dentre todos os compostos estudados, com CC50 de 0,34 mM, 0,93 mM e 0,58 mM para as células HEp-2, Caco-2 e HCT-8 respectivamente. A única cumarina que desenvolveu atividade hemolítica foi a balsamiferona, com porcentagem de hemólise de 8,87%

Implicit knowledge of the colours of natural scenes matches real colours

Some studies suggest that there is a memory colour effect for familiar objects but whether this effect generalizes to natural scenes is unclear. Here we tested this hypothesis with an experiment where observers adjust the colour gamut of unknown natural scenes to produce realistic images. The stimuli were images of natural scenes unknown to the observers synthesized from hyperspectral imaging data. The images were rendered under D65 and could be manipulated to adjust the colour gamut in the CIELAB (a*, b*) by a multiplicative factor between 1.5 and 0.5. The images were presented on a calibrated CRT computer screen driven by a ViSaGe MKII. In the experiment the observers adjusted the gamut by actuating freely on a joy-pad. At the beginning of each trial each image was presented with its colour gamut compressed or expanded by a random factor. The task of the observers was to adjust the gamut such that the image appeared real. Data from five observers with normal colour vision shows that, on average, the gamut selected by observers was within 2% of the original one. These results suggest that observers have implicit unbiased knowledge of the colours of natural scenes.info:eu-repo/semantics/publishedVersio

An Aγ-globin G->A gene polymorphism associated with β(0)39 thalassemia globin gene and high fetal hemoglobin production

Increase of the expression of γ-globin gene and high production of fetal hemoglobin (HbF) in β-thalassemia patients is widely accepted as associated with a milder or even asymptomatic disease. The search for HbF-associated polymorphisms (such as the XmnI, BCL11A and MYB polymorphisms) has recently gained great attention, in order to stratify β-thalassemia patients with respect to expectancy of the first transfusion, need for annual intake of blood, response to HbF inducers (the most studied of which is hydroxyurea)

Dnmt3a restrains mast cell inflammatory responses

DNA methylation and specifically the DNA methyltransferase enzyme DNMT3A are involved in the pathogenesis of a variety of hematological diseases and in regulating the function of immune cells. Although altered DNA methylation patterns and mutations in DNMT3A correlate with mast cell proliferative disorders in humans, the role of DNA methylation in mast cell biology is not understood. By using mast cells lacking Dnmt3a, we found that this enzyme is involved in restraining mast cell responses to acute and chronic stimuli, both in vitro and in vivo. The exacerbated mast cell responses observed in the absence of Dnmt3a were recapitulated or enhanced by treatment with the demethylating agent 5-aza-2′-deoxycytidine as well as by down-modulation of Dnmt1 expression, further supporting the role of DNA methylation in regulating mast cell activation. Mechanistically, these effects were in part mediated by the dysregulated expression of the scaffold protein IQGAP2, which is characterized by the ability to regulate a wide variety of biological processes. Altogether, our data demonstrate that DNMT3A and DNA methylation are key modulators of mast cell responsiveness to acute and chronic stimulation

Caracterização morfogênica e estrutural comparativa de cultivares de gramíneas forrageiras tropicais sob crescimento livre

Understanding of the morphogenetic characteristics allows comprehension of aspects related to the form and function of forage plants, providing opportunities to identify potentially high productive plants and distinct defoliation management requirements. The objective of this experiment was to carry out a comparative study of ten tropical forage grasses using morphogenetic and structural variables. Treatments corresponded to grasses of the Panicum genus (P. maximum cultivars Tanzânia and Mombaça) and the Brachiaria genus (B. brizantha cultivars Piatã, Marandu, Xaraés, Capiporã and Arapoty; B. decumbens cultivar Basilisk; B. humidicola cultivars Comum and Tupi), evaluated under free growth conditions.. Response variables were leaf appearance and elongation rates, phyllochron, stem elongation rate, final leaf length, number of live leaves per tiller, leaf life span and tiller appearance, death and survival rates. There was difference between cultivars for these variables, indicating a large variability within plants. Considering the morphogenetic and structural variables of leaves and tillers, B. brizantha had a similar pattern of variation to those of P. maximum, and B. Decumbens, similar to those of B. humidicola. Tiller appearance was large at the onset of the experiment and second and third generations comprised the large majority of tiller population for the cultivars Mombaça, Tanzânia, Xaraés and Capiporã. Group analysis based on plant morphogenetic and structural characteristics of leaves and tillers was an interesting way of grouping cultivars, indicating the importance and the potential of using morphogenesis in plant selection and evaluation programmes.O estudo das características morfogênicas permite compreender aspectos relativos à forma e função das plantas forrageiras além de possibilitar identificar plantas com potenciais produtivos e exigências de manejo diferentes. O objetivo deste trabalho foi avaliar, comparativamente, dez plantas forrageiras tropicais por meio de variáveis morfogênicas e estruturais. Os tratamentos corresponderam a cultivares pertencentes ao gênero Panicum (P. maximum cvs. Tanzânia e Mombaça) e ao gênero Brachiaria (B. brizantha cvs. Piatã, Marandu, Xaraés, Capiporã, e Arapoty; B. decumbens cv. Basilisk; B. humidicola cvs. Comum e Tupi), avaliados sob condições de crescimento livre. Foram avaliadas a taxa de aparecimento e alongamento de folhas, filocrono, taxa de alongamento de colmos, comprimento final da lâmina foliar, número de folhas vivas por perfilho, duração de vida das folhas e padrão demográfico de perfilhamento. Houve diferença entre cultivares para as variáveis, indicando grande variabilidade no material estudado. Considerando as características morfogênicas e estruturais de folhas e perfilhos, as B. brizantha apresentaram comportamento parecido com os P. maximum, e B. decumbens mais próximo das B. humidicola. Verificou-se que o aparecimento de perfilhos foi inicialmente elevado e que a segunda e, ou, terceira gerações contribuíram de forma significativa para o número total de perfilhos dos cultivares Mombaça, Tanzânia, Xaraés e Capiporã. A análise de agrupamento baseada nas características morfogênicas e estruturais de folhas e perfilhos foi um método interessante para agrupar cultivares, demonstrando a importância e o potencial de uso da morfogênese em trabalhos de seleção e avaliação de plantas forrageiras.FAPEMIGFederal University of Viçosa - Animal Science Departmen

TET2 regulates mast cell differentiation and proliferation through catalytic and non-catalytic activities

Dioxygenases of the TET family impact genome functions by converting 5-methylcytosine (5mC) in DNA to 5-hydroxymethylcytosine (5hmC). Here, we identified TET2 as a crucial regulator of mast cell differentiation and proliferation. In the absence of TET2, mast cells showed disrupted gene expression and altered genome-wide 5hmC deposition, especially at enhancers and in the proximity of downregulated genes. Impaired differentiation of Tet2- ablated cells could be relieved or further exacerbated by modulating the activity of other TET family members, and mechanistically it could be linked to the dysregulated expression of C/EBP family transcription factors. Conversely, the marked increase in proliferation induced by the loss of TET2 could be rescued exclusively by re-expression of wild-type or catalytically inactive TET2. Our data indicate that, in the absence of TET2, mast cell differentiation is under the control of compensatory mechanisms mediated by other TET family members, while proliferation is strictly dependent on TET2 expression

In vitro cytotoxic screening of coumarins

This study reports the cytotoxicity screening of 33 coumarins in a panel of human tumor cell lines (Caco-2: human colorectal adenocarcinoma, HCT-8: human ileocecal adenocarcinoma, and HEp-2: human larynx epidermoid carcinoma). The classic MTT assay was employed to evaluate the influence of samples on cellular viability. Following continuous incubation with cells for 72 h, all tested coumarins exhibited CC50 values ≥ 0.34 mM for all three cell lines. These findings indicate that all samples were not able to reduce the viability of tumor cell lines used in this study in clinically relevant concentrations. Some structure-activity relationships were established and could be used for the synthesis of derivatives with improved cytotoxic potential.Colegio de Farmacéuticos de la Provincia de Buenos Aire

CURSOS DE APRIMORAMENTO EM CONSTRUÇÃO CIVIL E INSTALAÇÕES ELÉTRICAS PREDIAIS

UNIPAMPA ALEGRET