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Poetic quotations accompany full-page photographs of various hummingbirds.
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Following Mandelbrot's fractal theory, it was found that the fractal dimension could be obtained in medical images by the concept of fractional Brownian motion. An estimation concept for determination of the fractal dimension based upon the concept of fractional Brownian motion was discussed. Two applications were found: 1) classification; 2) edge enhancement and detection. For the purpose of classification, a normalized fractional Brownian motion feature vector was defined from this estimation concept. It represented the normalized average absolute intensity difference of pixel pairs on a surface at different scales. The feature vector used relatively few data items to represent the statistical characteristics of the medical image surface and was invariant to linear intensity transformation. Finally, by calculating normalized fractional Brownian motion feature vectors in five different ultrasonic image surfaces, it was found that the classification of normal and abnormal ultrasonic liver images could be obtained from the differences between their feature vectors. For edge enhancement and detection application, a transformed image was obtained by calculating the fractal dimension of each pixel over the whole medical image. The fractal dimension value of each pixel was obtained by calculating the fractal dimension of a 7 x 7 pixel block centered on this pixel. Preliminary results using projection radiographs suggest that the fractal based image transformation appears to hold promise as an edge enhancement and preprocessing algorithm that does not increase noise in the way that gradient operators do. © 1989 IEEE
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Qualitative analysis is important because it is not subjective and does not have the potential for variation from one observer to another. A description is given of how statistical hypothesis testing can be used to select the quantitative descriptors best capable of distinguishing between normal and abnormal liver texture. Information is also presented on how both parametric and nonparametric discriminant analysis can be applied to determine how well the quantitative analysis compares with the qualitative diagnosis supplied for each case studied.
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The tendency by geographers to cast Hartshorne as either hero or villain in modern American geography is clearly represented in this essay considering the Hartshorne-Schaefer controversy, a dispute of almost mythical proportions in the modern history of American geography. Through analysis of unpublished and published documents, the author provides us with a wealth of historical information concerning the relation between the two antagonists and the events surrounding the publication of their methodological statements. The reportage has an additional, illocutionary impact that derives from the introduction of historical specificities into the discussion of mythologized events. The description and evaluation of the events surrounding this episode in American geography, especially its portrayal of spatial analysts in the uncharacteristic role of loyal sentimentalists, will probably add fuel to the dying embers of this controversy. -from Editors
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Prior exposure of isolated perifused rat islets to the monokine interleukin-1 (IL-1) amplifies their subsequent insulin secretory response to 10 mM glucose. This potentiating effect of the monokine is dose dependent, lasts for at least 45 min after IL-1 removal from the medium, and is not confined to glucose; IL-1 also potentiates the insulin secretory responses to tolbutamide and glyceraldehyde. IL-1 exposure of islets incubated with myo-[2†3H]inositol to label their phosphoinositides (PI) results in an increase in [3H]inositol efflux, an event that persists long after removal of IL-1 from the medium. Direct measurements of labeled inositol phosphate accumulation substantiate the concept that this sustained [3H] inositol efflux response is the direct result of a sustained increase in PI hydrolysis. These results expand the list of compounds that induce time-dependent potentiation in islets to include IL-1. This action of the monokine, mediated at least in part by Pi-derived second messenger molecules, may contribute to its postulated effects on insulin and glucose homeostasis. © 1989 by The Endocrine Society.
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Historically, social workers have been aware of the power of group resources and the importance of networking for their clients and for themselves as professionals. This article is the outgrowth of a collaboration paper presented by the authors at the Association of Baccalaureate Social Work Program Directors Annual Conference on September 22, 1986 in San Antonio, Texas. Four separate social work education programs within a state university system formed an informal collaborative association to address common concerns, develop strategies to enhance resources and to foster mutual support. The context, developmental process, barriers, activities, issues, outcomes and benefits of the collaborative association are described. © 1989 Taylor & Francis Group, LLC.
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