995 resultados para colonial science


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In the past decade several articles have been published in this journal and elsewhere by different authors, dealing with the institutionalization of science in Brazil, its origins and subsequent history. The emphasis has often been directed to the work of Brazilian scientists working abroad, to foreigners in Brazil, or to a few private individuals within the country, as well as to cultural, social, economic and political considerations. Much of the attention has also been focused on "academic" science, rather than on empirical or technical developments. The present article presents some of these situations, particularly in the mining district, where the application of technology, sometimes quite up-to-date for the time, tended to blur somewhat the distinction between science and its applications. It is hoped that this may start a debate which will enrich our historiography in this field and be of interest to those who want to assess Brazil's position in the history of science.

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José Antonio de Alzate y Ramírez (1737-1799) est reconnu aujourd’hui, entre autres choses, comme un des premiers journalistes, scientifiques, critiques littéraires et patriotes mexicains. Ce mémoire présente, dans un premier temps, une introduction à la vie et l’œuvre du personnage et rend compte de la réception globale de celle-ci, de 1831 à nos jours. Nous y montrons que les différents journaux d’Alzate, ses Diario literario de México (1768), Asuntos Varios sobre Ciencia y Arte (1772-1773), Observaciones sobre la física (1787-1788), et Gaceta de literatura (1788-1795), ont été étudiés principalement dans le contexte historique de la création de la nation mexicaine et que les intentions patriotiques ou proto-nationales qui lui ont été prêtées méritent d’être nuancées. Effectivement, bien qu’il ait publié plusieurs textes susceptibles de contribuer à améliorer certains domaines de l’économie américaine, tels que les activités minières, l’agriculture et les arts manuels, l’auteur révèle à travers son discours un désir de participer, au moyen de ses journaux, au mouvement scientifique européen. En ce sens, nous défendons l’hypothèse qu’Alzate ait choisi de pratiquer un type de journalisme spécifique, inspiré notamment du Journal des Sçavans (1665) et du Journal de Physique (1771-1773), qui lui permettrait de s’adresser autant à ses compatriotes, qu’aux membres de la République des Lettres. Nous présentons une étude comparative des similarités qui existent entre les publications d’Alzate et les deux journaux français ci-haut mentionnés, notamment en ce qui concerne les buts énoncés par leurs éditeurs ainsi que les modalités discursives et les thèmes qui les caractérisent. Dans le même ordre d’idée, nous soutenons que les publications d’Alzate présentent plusieurs des éléments clés qui définissent les journaux savants produits en Europe durant le dix-huitième siècle selon les études réalisées par Jean-Pierre Vittu. Enfin, nous expliquons comment le modèle du «journal savant» a été adapté par Alzate aux particularités de la Nouvelle-Espagne. Nous abordons, entre autres, les questions de la censure, de la critique et du manque de ressources financières dont il a souffert, facteurs qui, selon nos études, ont façonné l’entreprise du personnage. D’autre part, nous analysons les attitudes scientifiques adoptées par Alzate en tant que membre de la République des Lettres. Nous examinons aussi les principales sources de savoir qu’il a préconisées en tant qu’auteur afin d’accomplir certains devoirs propres aux membres de cette communauté.

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A review of poetry reflecting on the work of Alfred Russel Wallace, reflecting on ecopoetics, ecocriticism and spirituality, as well as on the limitations of colonial science and alternatives to Neo-Darwinism.

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Drawing upon Ontario Social Science and History curriculum documents and textbook imagery and language, this paper examines how narratives of settler landownership strategically present Indigenous and non-Indigenous peoples within the Canadian grand narrative. The curriculum and text material educators and learners are guided by ignore ongoing colonial violence towards Indigenous peoples and perpetuate the ideology of inevitable ‘peaceful’ interrelationships in national contexts. Learners develop identities in relation to land and how land is acquired. They come to understand themselves as part of a just nation in the particular sequence of Canadian Social Science and History teaching and learning. To go beyond simply adding content about Indigenous peoples in the classroom, educators and learners must adapt a decolonial approach to instead learn from Indigenous perspectives. Such a methodology would require the opening of a “third space” where the transmission of western curricular knowledge is interrupted. Educators and learners must create a space for problematizing the source itself and deconstruct the national grand narrative using inquiry, questioning and reflection, rather than repetition and regurgitation. This analysis reveals that particular placements of Indigenous peoples and settler Canadians in curriculum and classroom text material must be challenged by educators and learners to disrupt colonial narratives and to seek ongoing reconciliatory opportunities in and beyond the school walls.

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Monocoryne colonialis sp. nov. is described from the Aleutian Islands, Alaska. The new species is unusual among candelabrid hydroids in having a colonial growth form, differing from its congeners in the shape and size of hydranths, in having stolons that anastomose, and by having tentacles not fused or only partly fused into bract-like structures.

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Colonial spiders evolved a differential prey-capture behaviour in concert with their venom chemistry, which may be a source of novel drugs. Some highly active tetrahydro-beta-carboline (TH beta C) toxins were recently isolated from the venom of the colonial spider Parawixia bistriata; the spiders use these toxins as part of their chemical arsenal to kill and/or paralyze preys. The major TH beta C compound isolated from this venom was identified as 6-hydroxytrypargine, also known as PwTX-I. Most natural compounds of animal origin occur in low abundance, and the natural abundance of PwTX-I is insufficient for complete functional characterization. Thus, PwTx-I was synthesized using a Pictet-Spengler condensation strategy, and the stereoisomers of the synthetic toxin were separated by chiral chromatography. The fraction of venom containing a mixture of three natural TH beta C toxins and enantiomers of PwTx-I were analyzed for inhibition of monoamine oxidase (MAO)-A and -B and for toxicity to insects. We reveal that the mixture of the natural TH beta C toxins, as well as the enantiomers of PwTx-I, were non-competitive inhibitors of MAO-A and MAO-B and caused potent paralysis of honeybees. The (-)-PwTX-I enantiomer is 2-fold more potent than the (+)-PwTX-I enantiomer in the assays performed. (C) 2009 Elsevier Ltd. All rights reserved.

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El objetivo de este estudio es contribuir al entendimiento, desde un punto de vista histórico, del papel que juega el cine en los procesos de popularización de la ciencia, la medicina y la tecnología. El punto de partida es la consideración de la medicina y del cine como conjuntos complejos y multidimensionales de “prácticas y discursos” de carácter científico-tecnológico y, por tanto, como formas particulares de acción e interacción cotidiana entre personas, colectivos e instituciones que juegan un papel básico en los procesos de construcción y funcionamiento de las sociedades contemporáneas. Así, mediante el análisis de la representación y articulación de las prácticas y los discursos médico-sanitarios en el cine documental colonial español del primer franquismo, es decir, en el caso particular de la construcción, legitimación y consolidación de un régimen totalitario, se aportan algunas claves explicativas sobre las múltiples relaciones entre diferentes colectivos (expertos y no-expertos) en cuanto a la naturaleza y el nivel de intervención en los procesos de generación y gestión de conocimiento científico-tecnológico. Como resultado, el cine se revela como un espacio no sólo de evasión y entretenimiento, sino también de ciencia y educación, donde la capacidad de definir y solucionar problemas cotidianos de la población, y por tanto, su impacto en la construcción de la arquitectura social, ideológica, económica, política y cultural de las sociedades contemporáneas, se fundamenta en la combinación de sus aspectos como espectáculo narrativo y científico-tecnológico.

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This article discusses the processes inherent in the production of salpeter in Colonial Brazil. In the main, the texts seen here present recipes accompanied by chemical explanations of the processes which denote a knowledge of science at the time. Various difficulties confronting the authors, however, prevented an effective contribution to the development of techniques for the production of salpeter. Consequenttly, at the end of the Nineteenth Century, Brazilian rulers are still facing many problems to obtain this precious material.

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European naturalists explored Brazil in long scientific expeditions and published accounts that make up a rich and still largely untapped historiographic source for the understanding of the history of chemistry. The production of indigo dye, the manufacture of limestone, extraction and purification of saltpeter and the production of salt are discussed. Lime was used to whitewash walls and, mixed with whale oil, as cement to glue stones in buildings of the colonial period. It was prepared by burning seashells in specifically designed ovens. Saltpeter was produced by reacting naturally occurring calcium and magnesium nitrate with potassium-rich wood ashes to yield KNO3. NaCl was obtained by evaporating seawater under the sun. Indigo, a native plant, was cultivated and processed to produce the renowned dye, which was exported to Europe.

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Potassium carbonate, or potash, was the most important industrial chemical of the 18th century. It was essential for producing glass, soap, saltpeter, dyes, several drugs, and also used for bleaching linens, paper, and sugar. We examine here a book in which Brazilian author José Mariano da Conceição Veloso gathered his translations into Portuguese of English and French articles, letters, patents, and pamphlets with instructions on how to prepare potash. We discuss especially his version of Richard Watson's essay entitled 'Of saline substances', and Veloso's own 'Flora Alographica', a description of the Brazilian plants that could be used to prepare potash.

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This study aimed to evaluate the use of rosemary (Rosmarinus officinalis) extract (RE), celery (Apium graveolis), and low levels of NO3 and NO2 as natural agents to enhance the quality of colonial salami. Salami was produced according to three treatments: (A) Control: 0.1% curing salt; (B) Rosemary: 0.05% curing salt + 0.5% RE (rosemary extract); and (C) Rosemary+celery: 0.14% Veg 503 + 0.27% Veg 504 (sea salt plus celery) + 0.5% of RE (rosemary extract). There was no effect (P > 0.05) of the treatments on water activity, Na content, and residual NO3 and NO2. Fatty acids C18:2 and C20:4 were reduced (P < 0.05) during the ripening period in the Control treatment indicating possible oxidation. The use of celery resulted in lower pH values (P < 0.05) in the salami. Reduced addition of NO3 and NO2 resulted in salami lighter in color (higher L* values, P < 0.05) at the 12th day of ripening. In conclusion, celery-based products proved to be an effective source of NO2 and NO3 for color development, but the low pH of the product indicates the need for better evaluation of its use in fermented salami. The RE (rosemary extract) reduced fat oxidation in salami, but this needs further evaluation.

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The present work aims at elucidating the technology applied in the fabrication of ceramic objects by the ancient ceramists that inhabited the western border of Pantanal, Mato-Grosso do Sul, with the help of a multidisciplinary approach making use of chemical and physical methods of analysis. The potshards under study show the presence of different types of additives, as determined by scanning electron microscopy (SEM) and time of flight secondary ion mass spectrometry (ToF-SIMS). The dispersion of the additives within the ceramic matrix was also addressed by SEM, which shed light on the mounting technique used by the potters to assemble the ceramic vessels. Moreover, the tensile strength conferred to the pottery by the use of a specific type of additive was evaluated by applying a mechanical test. These results were correlated with the firing temperature of the potshards, determined by means of electron paramagnetic resonance (EPR). (C) 2010 Elsevier Ltd. All rights reserved.