157 research outputs found
Carlão Reichenbach
No full textEste artigo apresenta o cineasta Carlos Reichenbach pelo ponto de vista de seu ex-aluno, assistente e co-roteirista, numa análise inevitavelmente pessoal da obra e do artista, autor de filmes como O império do desejo, Filme demência, Alma corsária e Falsa loura. Reichenbach se adaptou como poucos aos ciclos e guinadas da produção cinematográfica brasileira. De 1968 a 2007 dirigiu 19 filmes de longa metragem, incluindo a participação em quatro longas de episódios. Foi roteirista, produtor, músico, ator, professor, crítico, programador e diretor de fotografia. Sua real importância para o cinema mundial ainda está por ser descoberta.This article presents the filmmaker Carlos Reichenbach from the point of view of his ex-student, assistant in four feature films and co-writer, in an unavoidably personal analysis of the films and the artist, author of O império do desejo (The Empire of Desire), Filme demência, Alma corsária (Buccaneer Soul) and Falsa loura (Fake Blonde), among others. Reichenbach knew as few others how to adapt to the cycles and turn-overs of the Brazilian cinematographic production. From 1968 to 2007 he directed 19 feature films, including episodes in four anthology films. He was a screenwriter, producer, musician, actor, critic, programmer and director of photography. His real importance to world cinema is yet to be discovered
Experimentos exploratórios: os contextos da descoberta e da justificativa nos trabalhos de Gray e Du Fay
No full textDissertação (mestrado) - Universidade Federal de Santa Catarina, Programa de Pós-Graduação em Educação Científica e Tecnológica, Florianópolis, 2015.A experimentação é normalmente entendida, no ensino de ciências, como um meio para refutar ou corroborar uma teoria e todo o seu processo dinâmico foge a uma reflexão metodológica. Principalmente na física, uma ciência experimental, é natural que as relações entre hipótese e experimentação estejam intimamente ligadas ao processo de construção do conhecimento. Entretanto, como enfatiza a literatura, é essencial refletir sobre esses vínculos que passam, muitas vezes, despercebidos tanto no âmbito da própria ciência como no procedimento pedagógico. Desta forma, o objetivo geral desta pesquisa foi evidenciar a dinâmica entre hipótese e experimentação na construção do conhecimento científico. Para tanto se desenvolveu um módulo de ensino que discute o conceito de experimentação exploratória (STEINLE, 1997; 2002) e a relação entre o contexto da descoberta e o contexto da justificativa, a partir dos estudos de Stephen Gray e Charles Du Fay em um momento incipiente da história da eletricidade. O módulo é constituído por um texto, dois artigos, três trechos de vídeos, seminários e uma atividade experimental, realizada em sala de aula. No primeiro semestre de 2013, ele foi implementado em um dos segmentos de uma disciplina sobre História da Ciência da Universidade Federal de Santa Catarina. Os dados obtidos através de um questionário aberto, em termos gerais, mostraram que a proposta é eficaz, promovendo uma satisfatória articulação entre o conteúdo histórico e aspectos específicos da filosofia da ciência.Abstract : Experimentation is usually understood in the teaching of science as a means to refute or corroborate a theory and all its dynamic process flees to a methodological reflection. Especially in physics, an experimental science, it is natural that the relationship between hypothesis and experimentation are closely linked to the knowledge construction process. However, as emphasized by the literature, it is essential to reflect on those ties that are often overlooked both in the science itself as the pedagogical procedure. Thus, the objective of this research was to demonstrate the dynamic between hypothesis and experimentation in the construction of scientific knowledge. Therefore developed a teaching module that discusses the concept of exploratory experimentation (STEINLE 1997, 2002) and the relationship between the context of discovery and the context of justification, from the studies of Stephen Gray and Charles Du Fay at a time incipient history of electricity. The module consists of a text, two articles, three sections of videos, seminars and experimental activity conducted in the classroom. In the first half of 2013, it was implemented in one of the segments of a course in the History of Science, Federal University of Santa Catarina. The data obtained through an open questionnaire, in general, showed that the proposal is effective, promoting a sound relationship between the historical content and specific aspects of the philosophy of science
DUAL SECOND DIMENSION COLUMN-DUAL DETECTION IN TWO-DIMENSIONAL COMPREHENSIVE GAS CHROMATOGRAPHY (GC×2GC-MS/FID): INCREASED INFORMATION IN OPTIMIZED SEPARATION CONDITIONS IN METABOLOMICS
No full textTwo-dimensional comprehensive GC-MS (GC×GC-MS) is the most advanced GC platform, among other, presenting a great potential for metabolomic studies because of its uncomparable separation power, sensitivity and possibility to obtain structured 2D patterns that can be adopted for. GC×GC-MS profiles can successfully be used for samples cross-comparisons to provide more extensive information than with 1D-GC-MS enabling to run simultaneously sample profiling and fingerprinting. However, the great diversity of chemical properties and the wide concentration ranges of these compounds in tissues and biological fluids is a significant challenge since methods need to be robust, reproducible, accurate and informative to enable samples to be reliably compared. In this perspective, the system configuration is a critical but challenging aspect requiring a careful tuning of columns diameters to avoid 2D column overloading and to improve quantitation accuracy and response linearity over a wider range of concentration [1]. This study investigates the advantages of a GC×2GC system in the metabolite profiling of urine samples from murine models of diet-induced metabolic derangements, characterized by hyperlipidemia, impaired glucose tolerance and insulin resistance. [2]. The system consists of a conventional first dimension column (1D - 30 m x 0.25 mm ID) coupled to two second dimension columns of variable lengths (2D-FID 1.6 m x 0.1 mm ID and 2D-MS 1.8 m x 0.1 mm ID) and combined with parallel MS and FID detection. In particular, male C57BL/6J mice were maintained on control rodent diet or high-fat high-fructose diet (HFHF, 45 kcal% Fat and 24 kcal% Fructose) for 22 weeks and urine samples were collected at different steps of the study. Our preliminary results show that urine sample profiles offer pivotal and comparative data on the presence and on the relative distribution of early markers of metabolic disease.
Besides, samples collected at the end of the experiments provide information on the global impact of the dietary manipulation on the systemic metabolism. Experimental results emphasized the advantages of the adopted configuration in terms of quantitation accuracy and precision in targeted profiling, maximization of the informative potentials due to the increased 2D column loadability and selectivity, reliability of untargeted fingerprinting performed by template matching approaches [3] on dual patterns.
References
[1] M.F. Almstetter, P.J. Oefner, K. Dettmer Analytical and Bioanalytical Chemistry 2012;402 (6):1993-2013.
[2] M. Collino, M. Aragno , S. Castiglia, G. Miglio, C. Tomasinelli et al. Br J Pharmacol. 160, 1892-902 (2010)
[3] S.E. Reichenbach, X. Tian , A.A. Boateng, C.A. Mullen , C. Cordero, Q. Tao, Anal Chem
Combined untargeted and targeted fingerprinting by comprehensive two-dimensional gas chromatography: revealing fructose-induced changes in mice urinary metabolic signatures
No full textThis study exploits the information potential of comprehensive two-dimensional gas chromatography configured with a parallel dual secondary column-dual detection by mass spectrometry and flame ionization (GC×2GC-MS/FID) to study changes in urinary metabolic signatures of mice subjected to high-fructose diets. Samples are taken from mice fed with normal or fructose enriched diets provided either in aqueous solution or in solid form and analyzed at three stages of the dietary intervention (1, 6, and 12 weeks).
Automated Untargeted and Targeted fingerprinting for 2D data elaboration is adopted for the most inclusive data mining of GC×GC patterns. The UT fingerprinting strategy performs a fully automated peak-region features fingerprinting and combines results from pre-targeted compounds and unknowns across the sample-set. The most informative metabolites, with statistically relevant differences between sample groups, are obtained by unsupervised multivariate analysis (MVA) and cross-validated by multi-factor analysis (MFA) with external standard quantitation by GC-MS.
Results indicate coherent clustering of mice urine signatures according to dietary manipulation. Notably, the metabolite fingerprints of mice fed with liquid fructose exhibited greater derangement in fructose, glucose, citric, pyruvic, malic, malonic, gluconic, cis-aconitic, succinic and 2-keto glutaric acids, glycine acyl derivatives (N-carboxy glycine, N-butyrylglycine, N-isovaleroylglycine, N-phenylacetylglycine), and hippuric acid. Untargeted fingerprinting indicates some analytes which were not a priori pre-targeted which provide additional insights: N-acetyl glucosamine, N-acetyl glutamine, malonyl glycine, methyl malonyl glycine, and glutaric acid. Visual features fingerprinting is used to track individual variations during experiments, thereby extending the panorama of possible data elaboration tools
Urinary metabolic fingerprinting of mice with diet-induced metabolic derangements by parallel dual secondary column-dual detection two-dimensional comprehensive gas chromatography
No full textThis study investigates the potential of a parallel dual secondary column- dual detection two-dimensional comprehensive GC platform (GC×2GC-MS/FID) for metabolic profiling and fingerprinting of mouse urine. Samples were obtained from a murine model that mimics a typical unhealthy Western diet featuring both high fat and sugar (HFHS) intake, which induces obesity, dyslipidemia, and insulin resistance. Urines collected at different steps of the study were used to obtain pivotal and comparative data on the presence and relative distributions of early markers of metabolic disease.
The data elaboration and interpretation work-flow includes an advanced untargeted fingerprinting approach, with peak-region features to locate relevant features to be quantified by external standard calibration. The reliability of untargeted fingerprinting is confirmed by quantitative results on selected relevant features that showed percentage of variations consistent with those observed by comparing raw data quantitative descriptors (2D Peak-Region Volumes and Percent of Response). Analytes that were up-regulated with a % of variation ranging from 30 to 1000, include pyruvic acid, glycerol, fructose, galactose, glucose, lactic acid, mannitol and valine. Down-regulation is evidenced for malonic acid, succinic acid, alanine, glycine, and creatinine.
Advanced fingerprinting also is demonstrated for effectively evaluating individual variations during experiments, thus representing a promising tool for personalized intervention studies. In this context, it is interesting to observe that informative features that were not discriminant for the entire population may be relevant for individuals
SALIVAGE – EU JPI Project The “form” makes the difference: unrevealing the differential impact of liquid and solid fructose in mice metabolic signatures by comprehensive two-dimensional gas chromatography
No full textInformatics for cross-sample analysis with comprehensive two-dimensional gas chromatography and high-resolution mass spectrometry (GCxGC-HRMS)
No full textThis paper describes informatics for cross-sample analysis with comprehensive two-dimensional gas chromatography (GCxGC) and high-resolution mass spectrometry (HRMS). GCxGC-HRMS analysis produces large data sets that are rich with information, but highly complex. The size of the data and volume of information requires automated processing for comprehensive cross-sample analysis, but the complexity poses a challenge for developing robust methods. The approach developed here analyzes GCxGC-HRMS data from multiple samples to extract a feature template that comprehensively captures the pattern of peaks detected in the retention-times plane. Then, for each sample chromatogram, the template is geometrically transformed to align with the detected peak pattern and generate a set of feature measurements for cross-sample analyses such as sample classification and biomarker discovery. The approach avoids the intractable problem of comprehensive peak matching by using a few reliable peaks for alignment and peak-based retention-plane windows to define comprehensive features that can be reliably matched for cross-sample analysis. The informatics are demonstrated with a set of 18 samples from breast-cancer tumors, each from different individuals, six each for Grades 1-3. The features allow classification that matches grading by a cancer pathologist with 78% success in leave-one-out cross-validation experiments. The HRMS signatures of the features of interest can be examined for determining elemental compositions and identifying compounds
Promenaea microptera Reichenbach 1881
No full textPromenaea microptera Reichenbach (1881: 134). Figs. 1; 2 A–B. Type:—S. loc., ex hort., fl. cult. at “James Veitch & Sons”, Chelsea, London, July 1881, A. d’Haene sub H.J. Veitch s.n. (lectotype designated by Meneguzzo 2020: W-R 40606 [W0132796] pencil icon on left, digital image!). Remaining original material:—S. loc., ex hort., fl. cult. at London, July 1881, B.S. Williams s.n. (remaining syntype W-R not found). = Zygopetalum micropterum Reichenbach (1881: 134), nom. nud. = Zygopetalum micropterum (Rchb.f.) Bentham & Hooker ex Bois (1893: 133). Rupicolous herb, 18–25 cm. Rhizome up to 2.0 cm long. Pseudobulbs 2.0–2.5 × 0.3–0.5 cm, ovate to fusiform. Leaves 19–25 × 0.9–1.3 cm, linear-lanceolate, apex acute. Inflorescence 1–2-flowered, 2–4 cm long, bracts 0.8–1.0 × ca. 0.3 cm; bracteoles ca. 0.8 × 0.3–0.4 cm, shorter than the pedicellate ovary; pedicellate ovary ca. 1 cm; sepals and petals ochre-green, spotless, ovate; dorsal sepal 1.8–2 × 0.4–0.5 cm, apex acute, lateral sepals 2–2.1 × 0.6–0.7 cm, apex acute; petals ca. 1.7 × 0.6 cm, apex acuminate; lip ca. 1.4 × 0.6 cm, white, outline elliptic, lateral lobes ca. 0.5 × 0.6 cm, with vinaceous stripes and spots, ovate, erect, apex obtuse, median lobe ca. 0.9 × 0.6 cm, with vinaceous stripes at the base, elliptic, apex acuminate; disk with apex emarginate to 2-toothed, attached to the base on both sides of the two lateral lobes, bearing a transverse crest; callus ca. 0.3 × 0.2 cm, subcylindrical, erect, inserted on the center of the crest, not extending over lateral lobes, apex bilobed; column ca. 1.2 cm long, ochre-green with margins and ventral portion vinaceous, subcylindrical, column foot ca. 0.4 cm long; anther cap ca. 0.4 × 0.3 cm, broadly oblong. Capsule not seen. Additional examined material:— BRAZIL. Rio de Janeiro: Nova Friburgo, 28 December 2018, J. R. Gastin s.n. (UPCB 93053!). S. loc., ex hort., fl. cult. at Glasnevin Botanic Garden, June 1890, F. W. Moore s.n. (K 879642, digital image!). S. loc., ex hort., fl. cult. at Upper Holloway, London, May 1896, B. S. Williams & Son (H. Williams) s.n. (K 879641, digital image!). S. loc., ex hort., fl. cult. at Glasnevin Botanic Garden, June 1900, s.coll. s.n. (F. W. Moore?) (K 879640, digital image!). S. loc., ex hort., fl. cult. at Kew Gardens, June 1915, s.coll. s.n. (K 879639, digital image!). S. loc., ex hort., s.d., s.coll. s.n. (W-R 31572 [W0132797], digital image!). Reichenbach (1881) characterized P. microptera by its light ochre-colored flowers, obtuse lateral lobes and lanceolate median lobe of the lip, with some narrow purple zones on the disk, similar maculae on the callus and the base of the lip, and a column with vinaceous margins at the basal portion. He highlighted that the shape of the flower was remarkably similar to that of P. xanthina, but with smaller lateral lobes, the keels at the base of the lip distinctly emarginate in front and with a small, peculiar callus on the disk. In the protologue of P. microptera, two specimens used by Reichenbach (1881) to describe the species are cited. The first was cultivated by Benjamin S. Williams (1822–1890, English horticulturist and orchidologist), but not found, since the location of his herbarium is unknown (Stafleu & Cowan 1988: 315). The second (W-R 40606), cultivated by Adolphe d’Haene in Ghent, Belgium and sent to Harry J. Veitch (1840–1924, English horticulturist), consists of two illustrations made in pencil, which are partially congruent with the original description, as differ a little as to the distribution of the maculae of the lip. Details of the floral morphology of the species can also be seen in the illustrations by Smith & Fitch (1915) (Figure 1). Bois (1893) and Cogniaux (1906) described the sepals and petals of P. microptera as creamy white or ochre-yellow and the lip as white, although the latter author has stated that he did not observe the specimens mentioned. Schlechter (1921) relied solely on the illustrations in the W-R herbarium (including most likely the lectotype designated by Meneguzzo 2020) to draw his taxonomic conclusions about P. microptera, highlighting the absence of dry material associated with the species. Hoehne (1953) drew on Cogniaux (1906) and Schlechter (1921) to describe P. microptera and considered that it has unique characters (yellowish white flowers, short and triangular lateral lobes and narrow and acute median lobe of the lip), which would certainly allow the easy recognition of the species in the field, should it be found again. Hoehne (1953) also pointed out with some surprise that Reichenbach had not conserved the specimens on which he based his original illustrations and that the species had not been collected since. Pabst and Dungs (1977) divided the genus into three informal groups, inserting P. microptera in the Promenaea xanthina alliance, characterized by the callus on the disk of the lip that does not reach the lateral lobes and the yellow flowers. The color of the flowers and the immaculate sepals and petals led Barberena (2014) to suggest the synonymization of P. microptera under P. xanthina. More recently, Meneguzzo (2020) synonymized P. microptera under Promenaea stapelioides subsp. xanthina (Lindley) Meneguzzo (2020: 165), but without detailing the reasons for this decision. However, the analysis of materials deposited in K, UPCB and W-R herbaria, mainly the specimen Gastin s.n. (UPCB 93053), together with the photographs of the specimen taken in the field (Figure 2), are conclusive and allowed us to affirm P. microptera as an autonomous species. Promenaea microptera is mainly characterized by its ochre-green and immaculate sepals and petals; white lip, with reddish-purple areas on the disk of the lip, on the callus, on the lateral lobes and more or less on the basal half of the median lobe, a bilobed callus at the apex, and column with vinaceous maculae mostly at the basal portion and margins. These morphological features are congruent with the protologue of the species. The characterization of P. microptera sepals and petals as creamy white, yellowish white or similar in color, was based on the colored illustration in the W-R herbarium, as indicated by Schlechter (1921). However, this floral coloration has not yet been observed in any living individual or mentioned on the label of any exsiccatae, which may be a morphological variation of the species or a misinterpretation. Therefore, Promenaea microptera is distinguished from P. xanthina, the closest species morphologically, mainly in the ochre-green sepals and petals (vs. bright yellow sepals and petals, rarely white), disk of the lip with a 2-toothed (vs. 3(–5)- toothed) and bilobed callus at the apex (vs. entire callus). Promenaea microptera can also be confused with P. guttata by having an elliptical median lobe, but they are also primarily distinguished by the color of the sepals and petals (ochre-green vs. pale-yellow) and callus of the lip (bilobed vs. entire). The scarcity of materials and information on P. microptera is notorious and highlighted by several authors in the last decades. The original protologue offers no information on the geographical origin of the original material used by Reichenbach. Bois (1893) was possibly the first to assume data on geographic distribution of the species when indicating Brazil. This position was maintained by other authors (e.g., Cogniaux 1906; Schlechter 1921; Hoehne 1953), considering that P. xanthina and the other species of Promenaea were known only from Brazil, although the true origin of the species has never been proven. Our findings, however, allowed us to put an end to this situation. Promenaea microptera is a microendemic species to the Brazilian Atlantic Forest, occurring around Nova Friburgo, in the state of Rio de Janeiro. The species was found growing rupicolously in moss-covered granitic rocks, near a stream in dense montane forests, at 800–1,000 m altitude. Given the absence of collections for over 100 years and the punctual distribution, P. microptera can be considered a rare species and conservation actions need to be taken in order to maintain the local population and ensure the species’ existence. E. C. S. was supported by Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) for a “Bolsa de Produtividade em Pesquisa CNPq - Nível 1D” [grant number 314642/2020-0].Published as part of Barberena, Felipe Fajardo V. A., Gastin, Jorge Rodrigues & Smidt, Eric De Camargo, 2022, Taxonomical remarks on Promenaea microptera (Orchidaceae: Epidendroideae): the rediscovery of a poorly known micro-endemic orchid from the Brazilian Atlantic Forest, pp. 229-233 in Phytotaxa 545 (2) on pages 229-232, DOI: 10.11646/phytotaxa.545.2.12, http://zenodo.org/record/653461
Exploring extra dimensions to capture saliva metabolite fingerprints from metabolically healthy and unhealthy obese patients by comprehensive two-dimensional gas chromatography featuring Tandem Ionization mass spectrometry
No full textThis study examines the information potential of comprehensive two-dimensional gas chromatography combined with time-of-flight mass spectrometry (GC×GC-TOF MS) and variable ionization energy (i.e., Tandem IonizationTM) to study changes in saliva metabolic signatures from a small group of obese individuals. The study presents a proof of concept for an effective exploitation of the complementary nature of tandem ionization data. Samples are taken from two sub-populations of severely obese (BMI > 40 kg/m2) patients, named metabolically healthy obese (MHO) and metabolically unhealthy obese (MUO). Untargeted fingerprinting, based on pattern recognition by template matching, is applied on single data streams and on fused data, obtained by combining raw signals from the two ionization energies (12 and 70 eV). Results indicate that at lower energy (i.e., 12 eV), the total signal intensity is one order of magnitude lower compared to the reference signal at 70 eV, but the ranges of variations for 2D peak responses is larger, extending the dynamic range. Fused data combine benefits from 70 eV and 12 eV resulting in more comprehensive coverage by sample fingerprints. Multivariate statistics, principal component analysis (PCA), and partial least squares discriminant analysis (PLS-DA) show quite good patient clustering, with total explained variance by the first two principal components (PCs) that increases from 54% at 70 eV to 59% at 12 eV and up to 71% for fused data. With PLS-DA, discriminant components are highlighted and putatively identified by comparing retention data and 70 eV spectral signatures. Within the most informative analytes, lactose is present in higher relative amount in saliva from MHO patients, whereas N-acetyl-D-glucosamine, urea, glucuronic acid γ-lactone, 2-deoxyribose, N-acetylneuraminic acid methyl ester, and 5-aminovaleric acid are more abundant in MUO patients. Visual feature fingerprinting is combined with pattern recognition algorithms to highlight metabolite variations between composite per-class images obtained by combining raw data from individuals belonging to different classes, i.e., MUO vs. MHO.Graphical abstract
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