343 research outputs found

    A general form on the logic puzzles of Boolos (Logic, Algebraic system, Language and Related Areas in Computer Science)

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    Boolos (1996) posed the puzzle "The hardest logic puzzle ever" which had been devised by Raymond Smullyan, and gave a solution in the style of biconditional questions. We introduce a simple formalization of the puzzle consisting of questions, answerers, and answers in terms of propositional logic, and show its adequacy by the truth values (0, 1) semantics. Then it turns out that the hardest logic puzzle can be considered as a natural extension of the puzzles of knights and knaves, i.e., lying and truth-telling by Smullyan. Here, we pose a general form of the puzzle, and provide partial solutions to some of the instances

    A Remark on Lattice Models of Second-Order Intuitionistic Propositional Logic (Theory and Applications of Proof and Computation)

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    We summarize a topological representation of the completely distributive algebraic lattices. This together with the discussion in [KF19] gives a definition of lattice models from an abstract viewpoint, with respect to which the completeness of the basic system of second-order intuitionistic propositional logic is ensured

    Synthesis and physical properties of (Pb0.5M0.5)(Sr,La)2CuOz (z~5; M = Fe, Co, Cu, and Zn)

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    (Pb0.5Cu0.5)(Sr0.5La0.5)2CuOz (abbreviated as (Pb,Cu)-"1-2-0-1") with superconducting transition temperature (Tc) of 25 K is a member (n = 1) of one of the homologous series of cuprate superconductors, (Pb4+,Cu2+)(Sr2+,Ln3+)2(Y3+,Ca2+)n-1Cu2+nO2-2n+3 (n = 1-4; Ln: lanthanoid elements). For the (Pb,Cu)-"1-2-0-1", substitution effects of 3d transition metal elements M (M = Fe, Co, and Zn) for the Cu site in the (Pb,Cu)-O charge-reservoir layer (labelled as Cu(1)) are systematically investigated. Because Fe, Co and Ni ions exist as divalent or trivalent in ionic crystals, the Sr2+/La3+ ratio in the (Sr,Ln) site is adjusted to satisfy charge neutrality, assuming that they are in a trivalent state. This results in the successful synthesis of new materials with nominal compositions of (Pb0.5M0.5)(Sr0.75La0.25)2CuOz (M = Fe and Co). This observation suggests that Fe and Co are trivalent in "1-2-0-1". For M = Zn, the nominal composition of (Pb0.5Zn0.5)(Sr0.5La0.5)2CuOz was found to yield a nearly single "1-2-0-1" phase. Temperature dependence of electrical resistivity and magnetization were measured, and superconductivity was confirmed only for the case of M = Zn with a Tc of 19.7 K. For these three materials, the distribution of Fe, Co and Zn between Cu(1) and another Cu site in the Cu-O2 plane labelled as Cu(2) was investigated employing transmission electron microscopy, which showed that Fe, Co, and Zn occupy both the Cu(1) and Cu(2) sites.Comment: 26 pages, 10 figure

    A taxonomic review of the genus Asterostegus (Echinodermata: Ophiuroidea) : with the description of a new species

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    A revision of the genus Asterostegus Mortensen, 1933 (Echinodermata: Ophiuroidea: Euryalidae) is based on seven specimens, including the holotype of Asterostegus maini McKnight, 2003. A new species, Asterostegus sabineae sp. nov., is described from off Reunion Island and two other species, A. tuberculatus Mortensen, 1933 and A. maini, are redescribed. A tabular key to the three species of the genus Asterostegus is provided. Some terminology of the taxonomy of euryalid ophiuroids is revised

    The distribution and number of Leu-7 (CD57) positive cells in lung tissue from patients with pulmonary fibrosis.

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    Leu-7 positive lymphocytes, including natural killer cells, play an important role in the immune system's surveillance function to prevent the development of cancer. The incidence of lung cancer is significantly high in patients with end-stage pulmonary fibrosis. We hypothesized that the number of Leu-7 positive cells may be decreased in areas of severe pulmonary fibrosis. To demonstrate this, Leu-7 positive cells were immunohistochemically stained in 41 lung specimens obtained from patients with idiopathic pulmonary fibrosis and pulmonary fibrosis associated with collagen vascular disorders. The number of Leu-7 positive cells was evaluated according to the pathological findings. In pathologically normal lung, Leu-7 positive cells were mostly found within the capillaries of the septa and rarely in the alveolar space or the stroma. The number of Leu-7 positive cells was 0.69 +/- 0.15 in areas of advanced fibrosis (n = 41), 2.39 +/- 0.60 in areas that had newly developeing fibrosis (n = 41), 1.14 +/- 0.57 in bronchiolitis obliterans organizing pneumonia (n = 9), and 1.35 +/- 0.87 in diffuse alveolar damage (DAD) (n = 11). The number of Leu-7 positive cells in areas of newly developing fibrosis (2.39 +/- 0.60) was significantly higher than that in areas of established fibrosis (0.69 +/- 0.15, P &#60; 0.05). Our present study demonstrates a significant decrease in the number of Leu-7 positive cells in areas of advanced fibrosis. This evidence may partly explain the high incidence of lung cancer associated with pulmonary fibrosis.</p

    GADD45β Determines Chemoresistance and Invasive Growth of Side Population Cells of Human Embryonic Carcinoma

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    Side population (SP) cells are an enriched population of stem, and the existence of SP cells has been reported in human cancer cell lines. In this study, we performed an SP analysis using 11 human cancer cell lines and confirmed the presence of SP cells in an embryonic carcinoma cell line, NEC8. NEC8 SP cells showed characteristics of cancer stem cells, such as high growth rate, chemoresistance and high invasiveness. To further characterize the NEC8 SP cells, we used DNA microarrays. Among 38,500 genes, we identified 12 genes that were over-expressed in SP cells and 1 gene that was over-expressed in non-SP cells. Among these 13 genes, we focused on GADD45b. GADD45b was over-expressed in non-SP cells, but the inhibition of GADD45b had no effect on non-SP cells. Paradoxically, the inhibition of GADD45b significantly reduced the viability of NEC8 SP cells. The inhibition of ABCG2, which determines the SP phenotype, had no effect on the invasiveness of NEC8 SP cells, but the inhibition of GADD45b significantly reduced invasiveness. These results suggest that GADD45b, but not ABCG2, might determine the cancer stem cell-like phenotype, such as chemoresistance and the high invasiveness of NEC8 SP cells, and might be a good therapeutic target

    EFFICACY OF HOMOGENOUS BONE GRAFTING IN MCCUNE-ALBRIGHT SYNDROME

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    A case of McCune-Albright syndrome is reported. The patient was a girl aged 8 years. The chief complaints were gait disturbance and a limp. Roentgenograms showed collapse and severe varus deformity of the femoral neck on the right side with 64° of neck-shaft angle. She had an episode of vaginal bleeding at the age 7 years. Valgus osteotomy of the right proximal femur for the correction of coxa vara and a bone transplantation of an allograft from her mother were performed. Seventy degrees of correction were obtained and the discrepancy of limb length was 1cm after the operation. Roentgenograms showed sufficient callus and solid union between the fragments and the grafted bone 1 year after the operation. Frozen allograft bone was very effective in stimulating bone induction even in fibrous lesions of a patient with McCune-Albright syndrome. Immunology of bone grafts, HLA antigens, osteogenesis in grafts, and the etiology of McCune-Albright syndrome were discused
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