94 research outputs found

    La sinistra:italiana una commedia in tre atti.

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    L’entrata nella seconda Repubblica è stata scandita dalla marcia trionfale della sinistra in predicato di vincere le elezioni politiche. I risultati elettorali più gratificanti della sinistra sono stati la traballante vittoria del 1996 e le non vittorie (sostanziali pareggi) del 2006 e del 2013, al contrario erano certe nelle previsioni e nei fatti le vittorie berlusconiane del 2001 e del 2008

    Quantifying fracture geometry with X-ray tomography: Technique of Iterative Local Thresholding (TILT) for 3D image segmentation

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    This paper presents a new method—the Technique of Iterative Local Thresholding (TILT)—for processing 3D X-ray computed tomography (xCT) images for visualization and quantification of rock fractures. The TILT method includes the following advancements. First, custom masks are generated by a fracture-dilation procedure, which significantly amplifies the fracture signal on the intensity histogram used for local thresholding. Second, TILT is particularly well suited for fracture characterization in granular rocks because the multi-scale Hessian fracture (MHF) filter has been incorporated to distinguish fractures from pores in the rock matrix. Third, TILT wraps the thresholding and fracture isolation steps in an optimized iterative routine for binary segmentation, minimizing human intervention and enabling automated processing of large 3D datasets. As an illustrative example, we applied TILT to 3D xCT images of reacted and unreacted fractured limestone cores. Other segmentation methods were also applied to provide insights regarding variability in image processing. The results show that TILT significantly enhanced separability of grayscale intensities, outperformed the other methods in automation, and was successful in isolating fractures from the porous rock matrix. Because the other methods are more likely to misclassify fracture edges as void and/or have limited capacity in distinguishing fractures from pores, those methods estimated larger fracture volumes (up to 80 %), surface areas (up to 60 %), and roughness (up to a factor of 2). These differences in fracture geometry would lead to significant disparities in hydraulic permeability predictions, as determined by 2D flow simulations

    The effect of various drugs with neuroendocrine activity and transdermal estradiol on plasma gonadotropin concentrations after ovariectomy in reproductive-aged women.

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    In the present study we compared the effect of different neuroactive drugs with that of estrogen treatment on the ovariectomy-induced plasma luteinizing hormone (LH) and follicle-stimulating hormone (FSH) changes. A total of 35 menstruating women undergoing ovariectomy were randomly divided into five groups of 7 patients each, receiving a 4-week treatment with oral clonidine, lisuride and sodium valproate, transdermal 17 beta-estradiol, or placebo. The treatment started the day after ovariectomy. Surgery was done during the early follicular phase of the cycle. Blood samples were collected before and after 3, 5, 7, 14, 21 and 28 days of treatment. During the treatment, hot flushes were subjectively recorded. The placebo-treated group showed a progressive increase in plasma LH and FSH concentration during the month following ovariectomy. The same changes occurred in the lisuride and sodium valproate treated groups. Plasma LH levels in ovariectomized women treated with clonidine showed an increase which was higher than in placebo-treated women (p less than 0.01), while FSH levels were similar to those in the placebo group. In the estradiol-treated group the increase in both gonadotropins was significantly less (p less than 0.01) than in the placebo group. The frequency and intensity of hot flushes were high in placebo and sodium valproate treated subjects, being significantly reduced by clonidine, lisuride and estrogen treatment. Our results seem to indicate that clonidine treatment modulates the LH postcastration rise and that both neuroendocrine and gonadal mechanisms influence the changes in the activity of the GnRH-pituitary axis following ovariectomy
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