996 resultados para Huxley, Thomas Henry, 1825-1895.


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Includes bibliographical references and index.

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On verso of t.-p.: Extracted from the Henry memorial volume published by order of Congress.

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The exponential growth of studies on the biological response to ocean acidification over the last few decades has generated a large amount of data. To facilitate data comparison, a data compilation hosted at the data publisher PANGAEA was initiated in 2008 and is updated on a regular basis (doi:10.1594/PANGAEA.149999). By January 2015, a total of 581 data sets (over 4 000 000 data points) from 539 papers had been archived. Here we present the developments of this data compilation five years since its first description by Nisumaa et al. (2010). Most of study sites from which data archived are still in the Northern Hemisphere and the number of archived data from studies from the Southern Hemisphere and polar oceans are still relatively low. Data from 60 studies that investigated the response of a mix of organisms or natural communities were all added after 2010, indicating a welcomed shift from the study of individual organisms to communities and ecosystems. The initial imbalance of considerably more data archived on calcification and primary production than on other processes has improved. There is also a clear tendency towards more data archived from multifactorial studies after 2010. For easier and more effective access to ocean acidification data, the ocean acidification community is strongly encouraged to contribute to the data archiving effort, and help develop standard vocabularies describing the variables and define best practices for archiving ocean acidification data.

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Los estudios sobre la comunidad genovesa del Reino de Granada suelen centrarse en las actividades desarrolladas en el territorio y rara vez en la reconstrucción de trayectorias individuales, circunstancia determinada por el recurso casi exclusivo a los protocolos notariales. El caso de Francesco Grimaldi es singular por muchas razones: su localización en fuentes de naturaleza muy variada –protocolos notariales de Granada y Málaga, Registro del Sello de Simancas y Granada, Chancillería de Valladolid, el epistolario del comendador Fuensalida y el archivo privado de la familia Grimaldo de Cáceres– ha permitido seguir su presencia y sus actividades en Granada, la Corte e Inglaterra –donde desempeñó un papel fundamental en el matrimonio entre Catalina de Aragón y Enrique VIII–. Así se conoce su interés por los préstamos y el negocio de la renta, las circunstancias de su matrimonio con Francisca de Cáceres y la adquisición de un importante patrimonio en el reino granadino.

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Durante el siglo XIX el transformismo irrumpe en el panorama científico, una irrupción cuyas implicaciones filosóficas y sociales se traducen, entre otros, en obras teatrales en las que la temática refleja la difusión de estas nuevas ideas. Les deux Jockos, de 1825, ejemplifica ese grupo de representaciones que ponen en escena el debate transformista en una sociedad todavía dominada por los preceptos fijistas defendidos desde las instituciones y las élites sociales de la época. Así pues, el análisis de la obra permitirá desvelar aquellos elementos relacionados con el nuevo paradigma de naturaleza propuesto, al tiempo que evidencia la capacidad de influencia de la realidad histórica, social y cultural sobre el género teatral.

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Wahrscheinlich war es ja nur ein Versuch einer alteingesessenen Institution der Massenmedien, sich bei „den Leuten, die man früher ‚das Publikum‘ nannte“ („the people formerly known as the audience“; Rosen, 2006, n.pag.) wieder einzuschmeicheln. Dennoch, die Anerkennung des kollektiven „You“ in YouTube und anderen kollaborativen Onlineplattformen als Person des Jahres durch das amerikanische Magazin Time (Grossman, 2007) liefert ein weiteres Indiz für die wachsende Bedeutung solcher Projekte zur gemeinschaftlichen Produktion und Distribution von Inhalten. Kreative Websites wie Flickr und YouTube, kollaborative Wissenssammlungen von Wikipedia über Digg bis zu Google Earth, nutzergesteuerte Diskussionen in Slashdot, OhmyNews, und der allgemeinen Blogosphäre, aber auch die Softwareentwicklungsgemeinschaften im Open‐Source‐Bereich – sie alle dienen als Beispiele für diese nun etablierten Trend zur Entwicklung neuer Produktions‐, Geschäfts‐, Gemeinschafts‐ und Selbstlenkungsmodelle, die wesentlich durch zunehmend komplexere Web‐2.0‐Tools unterstützt werden. Hinter diesen Beispielen wird eine allgemeiner Tendenz sichtbar, die aus ökonomischer Sicht bereits von Yochai Benkler als „commons‐based peer production“ (2006), und von Eric von Hippel als „democratizing innovation" (2005) beschrieben worden ist. Henry Jenkins spricht zudem von einer „convergence culture“ (2006), in der solche nutzergesteuerten Projekte operieren, und es können auch Verbindungen zwischen diesen stärker aktive gewordenen Nutzern und Alvin Tofflers professionellen Konsumenten, den „Prosumers“ ziehen (1971).

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Thomas Young (1773-1829) carried out major pioneering work in many different subjects. In 1800 he gave the Bakerian Lecture of the Royal Society on the topic of the “mechanism of the eye”: this was published in the following year (Young, 1801). Young used his own design of optometer to measure refraction and accommodation, and discovered his own astigmatism. He considered the different possible origins of accommodation and confirmed that it was due to change in shape of the lens rather than to change in shape of the cornea or an increase in axial length. However, the paper also dealt with many other aspects of visual and ophthalmic optics, such as biometric parameters, peripheral refraction, longitudinal chromatic aberration, depth-of-focus and instrument myopia. These aspects of the paper have previously received little attention. We now give detailed consideration to these and other less-familiar features of Young’s work and conclude that his studies remain relevant to many of the topics which currently engage visual scientists.

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Australia’s Future Tax System Review, headed by the then head of the Australian Treasury, and the Productivity Commission’s Research Report on the not for profit sector, both examined the state of tax concessions to Australia’s not for profit sector in the light of the High Court’s decision in Commissioner of Taxation v Word Investments Ltd. Despite being unable to quantify with any certainty the pre- or post-Word Investments cost of the tax concessions, both Reports indicated their support for continuation of the income tax exemption. However, the government acted in the 2011 Budget to target the not for profit income tax concessions more precisely, mainly on competitive neutrality grounds. This article examines the income tax exemption by applying the five taxation design principles, proposed in the Australia’s Future Tax System Review, for assessing tax expenditure. The conclusion is that the exemptions can be justified and, further, that a rationale for the exemption can be consistent with the reasoning in the Word Investments case.

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In addition to his work on physical optics, Thomas Young (1773-1829) made several contributions to geometrical optics, most of which received little recognition in his time or since. We describe and assess some of these contributions: Young’s construction (the basis for much of his geometric work), paraxial refraction equations, oblique astigmatism and field curvature, and gradient-index optics.

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Purpose: James Clerk Maxwell is usually recognized as being the first, in 1854, to consider using inhomogeneous media in optical systems. However, some fifty years earlier Thomas Young, stimulated by his interest in the optics of the eye and accommodation, had already modeled some applications of gradient-index optics. These applications included using an axial gradient to provide spherical aberration-free optics and a spherical gradient to describe the optics of the atmosphere and the eye lens. We evaluated Young’s contributions. Method: We attempted to derive Young’s equations for axial and spherical refractive index gradients. Raytracing was used to confirm accuracy of formula. Results: We did not confirm Young’s equation for the axial gradient to provide aberration-free optics, but derived a slightly different equation. We confirmed the correctness of his equations for deviation of rays in a spherical gradient index and for the focal length of a lens with a nucleus of fixed index surrounded by a cortex of reducing index towards the edge. Young claimed that the equation for focal length applied to a lens with part of the constant index nucleus of the sphere removed, such that the loss of focal length was a quarter of the thickness removed, but this is not strictly correct. Conclusion: Young’s theoretical work in gradient-index optics received no acknowledgement from either his contemporaries or later authors. While his model of the eye lens is not an accurate physiological description of the human lens, with the index reducing least quickly at the edge, it represented a bold attempt to approximate the characteristics of the lens. Thomas Young’s work deserves wider recognition.