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Image segmentation remains an important, but hard-to-solve, problem since it appears to be application dependent with usually no a priori information available regarding the image structure. In recent years, many image segmentation algorithms have been developed, but they are often very complex and some undesired results occur frequently. In this paper, we propose a pixel classification based color image segmentation using quaternion exponent moments. Firstly, the pixel-level image feature is extracted based on quaternion exponent moments (QEMs), which can capture effectively the image pixel content by considering the correlation between different color channels. Then, the pixel-level image feature is used as input of twin support vector machines (TSVM) classifier, and the TSVM model is trained by selecting the training samples with Arimoto entropy thresholding. Finally, the color image is segmented with the trained TSVM model. The proposed scheme has the following advantages: (1) the effective QEMs is introduced to describe color image pixel content, which considers the correlation between different color channels, (2) the excellent TSVM classifier is utilized, which has lower computation time and higher classification accuracy. Experimental results show that our proposed method has very promising segmentation performance compared with the state-of-the-art segmentation approaches recently proposed in the literature. [ABSTRACT FROM AUTHOR]

Abstract: Most parameters of steel tube can be acquired from the computer tomography (CT) image of its section. However, a large number of projections are needed to reconstruct the image, so the collection and calculation of the projection data consume too much time to inspect steel tube online. For the purpose of solving the problem, we adopt the CT system that can collect the projection data without mechanical scanning motion and propose a modified penalized exponential EM (PEEM) algorithm to reconstruct the steel tube section from only three projections. In the method, the image area is restricted and the pixel value is binarized in order to decrease the number of projections needed and accelerate the convergence speed. At last, the problems of flaw inspection, influence of the restricted area and spatial resolution are discussed. The experiment results show that the accuracy and the reconstruction time of the algorithm meet the requirements of online inspection of steel tube, so it might be possible to be used in practical production. [Copyright &y& Elsevier]

Graves' disease (GD) is one of the most common autoimmune conditions, but the mechanisms underlying the associated induction of autoimmunity are not known. We explored the role of peripheral lymphocyte subpopulations in disease pathogenesis. In total, 32 patients and 40 age- and sex-matched healthy controls were recruited in this study. Peripheral levels of T, B, NK, CD4+ T, CD8+ T, Th1, Th2, Th17, and Treg cells were measured using flow cytometry. For all patients, we compared all lymphocyte subpopulations between GD patients and healthy controls. Changes in patient lymphocyte subsets were compared before and after treatment. The absolute numbers of circulating Th17 cells (0.45 ± 1.16, p > 0.05) between GD patients and healthy controls were not significantly different. However, the percentage of Th17 cells was significantly increased (0.25 ± 0.11, p < 0.05). The absolute numbers and percentages of circulating Tregs in GD patients were significantly decreased compared with those in healthy participants (11.61 ± 2.75, p < 0.05). There was a significant difference in Treg absolute numbers between the untreated and drug-treated groups. Furthermore, we found that the Treg percentage in untreated patients (mean=4.78) was not significantly different from that in the drug-treated group (mean=4.81). In addition, circulating Treg absolute numbers in GD patients with exophthalmos were significantly lower than those in GD patients without exophthalmos (9.96 ± 4.16, p < 0.05). A similar trend was observed in GD patients with weight loss (11.97 ± 3.28, p < 0.05). GD pathogenesis was associated with a lower Treg population and an increased Th17/Treg ratio (T helper cell 17/ regulatory T cells). Th17 cells in this study were not related to the disease. Furthermore, anti-thyroid drug therapy improved immune-mediated system disorders. Finally, we found lower absolute numbers of circulating Tregs in GD patients with certain positive signs, such as exophthalmos and/or weight loss. Thus, immune changes are correlated with partial clinical manifestations. • The pathogenesis of Graves'disease is associated with lower Treg absolute counts and increased ratio of Th17/Treg. • Th17 cells in this study were proved to be not related to the disease. • Antithyroid drug therapy may improve immune-mediated system disorders to some extent. • The absolute counts of Tregs in peripheral blood of Graves'disease patients with some positive signs was reduced. [ABSTRACT FROM AUTHOR]

Abstract: The practicality of using juvenile in vitro embryo transfer (JIVET) on a field scale in China was evaluated in each of three seasons (summer, autumn and winter) from 2006 to 2007. A total of 102 donor Merino lambs (18 summer, 69 autumn and 15 winter) aged 4–8 weeks were stimulated with 4×40mg FSH administered at 12h intervals plus 400IU PMSG given at the time of the first FSH treatment. Overall, 89.2% (91/102) of the lambs exhibited follicle development and 79.1±65.5 (mean±S.D.) cumulus–oocyte complexes were recovered per donor lamb. Compared with the groups of summer (84.9±55.3) and autumn (83.6±70.8) lambs, the number of recovered cumulus–oocyte complexes was significantly decreased in winter (51.4±43.7; p <0.05). After recovery, the cumulus–oocyte complexes were matured and fertilized in vitro using frozen–thawed semen and culture in synthetic oviduct fluid medium to the 2–4-c stage of development, when they were transferred surgically in groups of 3–8 (5.33±1.47) to the ipsilateral uterine horn of a total of 603 synchronized recipients. The overall mean proportion of cumulus–oocyte complexes developing to 2-c embryos was 61.4% (4308/7013) and differed significantly between seasons (summer 38.5%, autumn 66.1%, winter 74.6%; p <0.01). Pregnancy rate assessed by ultrasound examination approximately 60 days after embryo transfer was 54.4% (328/603) overall, and 36.7% (221/603) of the recipients maintained their pregnancy to full-term, producing an average 1.49 (330/221) offspring, of which 1.21 (267/221) were viable and healthy lambs, per pregnant recipient. Pregnancy rate at day 60 was affected by season (summer 40.5%, autumn 56.7%, winter 55.7%; p <0.05), but did not differ significantly between seasons at full-term (summer 34.2%, autumn 38.9%, winter 30.4%; p >0.05). Based on the number of donors stimulated, the total number of offspring and viable progeny produced per donor lamb in autumn (5.81 and 4.87) was significantly (p <0.01) higher than that of summer (2.79 and 1.94) and winter (4.24 and 3.31). This study showed that each donor lamb after stimulation produced an average of 48.6 transferable embryos that resulted in 4.04 viable and healthy progeny. These results indicate that JIVET is a cost-effective method of multiplying desirable sheep genotypes in China. [Copyright &y& Elsevier]