990 resultados para Birkerts, Gunnar, 1925-
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Dinoflagellates of the genus Ceratium are chiefly marine but there are rare occurrences in freshwater. In this study we analyze the invasion and progressive establishment of Ceratium furcoides, an exotic species, in the Furnas Reservoir. Samples were taken at 36 points in the reservoir, during the months of March, June, September and December, 2007. Measurements of some physical and chemical variables were simultaneously performed at each site. The occurrence of C. furcoides was registered at 20 sites, with densities varying between 0.57 and 28,564,913.0 ind.m-3. Blooms of this species were recorded in points which were classified as mesotrophic, coinciding with the places receiving high amounts of untreated domestic sewage. C. furcoides density was correlated with temperature, nutrients (nitrate and nitrite) and water electric conductivity. The highest density was recorded in June when temperature was low. The presence of Ceratium furcoides in the reservoir apparently has not yet affected the reservoir water quality or other plankton communities. However, if it becomes fully established it could perhaps become a problem in the reservoir or even to spread out to other reservoirs in Rio Grande basin.
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Directora: Juana Teresa Guerra de la Torre. Programa de doctorado: Nuevas perspectivas cognitivas en los estudios de lengua, literatura y traducción
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Il quadro tematico della tesi è la storia politica e culturale delle relazioni tra il cattolicesimo democratico di origine «popolare» e la tradizione del liberalismo italiano, in un arco cronologico compreso tra l’antifascismo dell’Aventino e la fondazione della Democrazia Cristiana. L’ipotesi della ricerca è che proprio in questo «lungo viaggio» la classe dirigente del cattolicesimo politico (a cominciare dalla leadership di Alcide De Gasperi) abbia completato quel processo di acculturazione in senso «liberale» che le avrebbe consentito di guidare consensualmente l’uscita dal fascismo nel secondo dopoguerra.
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Studio storiografico condotto su fonti archivistiche, filmiche e sulla stampa locale e specializzata che ricostruisce dettagliatamente l'ambiente cittadino d'inizio Novecento nel quale si sono diffusi i primi spettacoli cinematografici, determinandone le caratteristiche e tracciandone l'evoluzione fra 1896 e 1925. L'avvento della cinematografia è strettamente connesso a un processo di modernizzazione del volto urbano, degli stili di vita, delle idee e il cinema si salda a queste istanze di rinnovamento, con una precisa ricaduta sull'immagine della città e sull'esperienza dei suoi cittadini appartenenti alle diverse classi sociali.
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BackgroundDespite the increasingly higher spatial and contrast resolution of CT, nodular lesions are prone to be missed on chest CT. Tinted lenses increase visual acuity and contrast sensitivity by filtering short wavelength light of solar and artificial origin.PurposeTo test the impact of Gunnar eyewear, image quality (standard versus low dose CT) and nodule location on detectability of lung nodules in CT and to compare their individual influence.Material and MethodsA pre-existing database of CT images of patients with lung nodules >5 mm, scanned with standard does image quality (150 ref mAs/120 kVp) and lower dose/quality (40 ref mAs/120 kVp), was used. Five radiologists read 60 chest CTs twice: once with Gunnar glasses and once without glasses with a 1 month break between. At both read-outs the cases were shown at lower dose or standard dose level to quantify the influence of both variables (eyewear vs. image quality) on nodule sensitivity.ResultsThe sensitivity of CT for lung nodules increased significantly using Gunnar eyewear for two readers and insignificantly for two other readers. Over all, the mean sensitivity of all radiologist raised significantly from 50% to 53%, using the glasses (P value = 0.034). In contrast, sensitivity for lung nodules was not significantly affected by lowering the image quality from 150 to 40 ref mAs. The average sensitivity was 52% at low dose level, that was even 0.7% higher than at standard dose level (P value = 0.40). The strongest impact on sensitivity had the factors readers and nodule location (lung segments).ConclusionSensitivity for lung nodules was significantly enhanced by Gunnar eyewear (+3%), while lower image quality (40 ref mAs) had no impact on nodule sensitivity. Not using the glasses had a bigger impact on sensitivity than lowering the image quality.
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This digital object was funded in part through a grant from the Andrew W. Mellon Foundation. The digitalization of this object was part of a collaborative effort with the Washington Research Library Consortium and George Washington University.