67 research outputs found

    Obstacle avoidance by changing running path for an autonomous running vehicle applying visual servoing

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    This paper describes an improved running control algorithm based on the visual servoing in consideration of the turning back of a running path to avoid an obstacle on the path by changing the running path. This paper also describes an experimental autonomous running vehicle to demonstrate the algorithm. As a vision sensor, the vehicle equips with a video-rate stereo rangefinder which processes color images from stereo CCD cameras and is developed in the authors' laboratory. From the several basic autonomous running experiments, it is concluded that the experimental vehicle runs smoothly any planned path composed of several teaching routes by transferring routes. It is also concluded that the vehicle can turn back on a path including turning back of route transference</p

    Identification and characterization of an oocyte factor required for development of porcine nuclear transfer embryos.

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    Nuclear reprogramming of differentiated cells can be induced by oocyte factors. Despite numerous attempts, these factors and mechanisms responsible for successful reprogramming remain elusive. Here, we identify one such factor, necessary for the development of nuclear transfer embryos, using porcine oocyte extracts in which some reprogramming events are recapitulated. After incubating somatic nuclei in oocyte extracts from the metaphase II stage, the oocyte proteins that were specifically and abundantly incorporated into the nuclei were identified by mass spectrometry. Among 25 identified proteins, we especially focused on a multifunctional protein, DJ-1. DJ-1 is present at a high concentration in oocytes from the germinal vesicle stage until embryos at the four-cell stage. Inhibition of DJ-1 function compromises the development of nuclear transfer embryos but not that of fertilized embryos. Microarray analysis of nuclear transfer embryos in which DJ-1 function is inhibited shows perturbed expression of P53 pathway components. In addition, embryonic arrest of nuclear transfer embryos injected with anti-DJ-1 antibody is rescued by P53 inhibition. We conclude that DJ-1 is an oocyte factor that is required for development of nuclear transfer embryos. This study presents a means for identifying natural reprogramming factors in mammalian oocytes and a unique insight into the mechanisms underlying reprogramming by nuclear transfer

    A Study of Cases with Rib Metastasis Difficult to Distinguish from Microfractures on Bone Scintigraphy

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    A retrospective study of about 10,000 cases at Kawasaki Medical School Hospital on whom bone scans were performed over a six year period revealed five cases in which metastasis was mistaken for a benign rib lesion. This mistake occurred because the accumulation pattern of the radionuclide in the rib region on the bone scan indicated a so-called "hot spot" observed with microfractures rather than the rod-like increased accumulation along costal bones that is coincident with the finding of bone metastasis. This experience suggests that solitary hot spots in the rib region on bone scans should be diagnosed carefully, as such an accumulation is most frequently associated with a benign etiology but rarely may be a malignant lesion
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