724 research outputs found

    5-State Rotation-Symmetric Number-Conserving Cellular Automata are not Strongly Universal

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    We study two-dimensional rotation-symmetric number-conserving cellular automata working on the von Neumann neighborhood (RNCA). It is known that such automata with 4 states or less are trivial, so we investigate the possible rules with 5 states. We give a full characterization of these automata and show that they cannot be strongly Turing universal. However, we give example of constructions that allow to embed some boolean circuit elements in a 5-states RNCA

    Pairing collectivity in medium-mass neutron-rich nuclei near drip-line

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    We look for collective excitations originating from the strong surface pairing in unstable nuclei near the neutron drip-line. The soft dipole excitation is such a pairing mode as it exhibits a character of core-vs-dineutron motion. Possibility of the hydrodynamic phonon mode (the Anderson-Bogoliubov mode) is also discussed.Comment: 9 pages, a talk presented at Collective Motion in Nuclei under Extreme Conditions (COMEX2), June 20-23, 2006, St. Goar, German

    Characterizing Vickrey allocation rule by anonymity

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    We consider the problem of allocating finitely many units of an indivisible good among a group of agents when each agent receives at most one unit of the good and pays a non-negative price. For example, imagine that a government allocates a fixed number of licenses to private firms, or that it distributes equally divided lands to households. Anonymity in welfare is a condition of impartiality in the sense that it requires allocation rules to treat agents equally in welfare terms from the viewpoint of agents who are ignorant of their own valuations or identities. We show that the Vickrey allocation rule is the unique allocation rule satisfying strategy-proofness, anonymity in welfare, and individual rationality

    The melanoma-specific graded prognostic assessment does not adequately discriminate prognosis in a modern population with brain metastases from malignant melanoma

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    The melanoma-specific graded prognostic assessment (msGPA) assigns patients with brain metastases from malignant melanoma to 1 of 4 prognostic groups. It was largely derived using clinical data from patients treated in the era that preceded the development of newer therapies such as BRAF, MEK and immune checkpoint inhibitors. Therefore, its current relevance to patients diagnosed with brain metastases from malignant melanoma is unclear. This study is an external validation of the msGPA in two temporally distinct British populations.Performance of the msGPA was assessed in Cohort I (1997-2008, n=231) and Cohort II (2008-2013, n=162) using Kaplan-Meier methods and Harrell's c-index of concordance. Cox regression was used to explore additional factors that may have prognostic relevance.The msGPA does not perform well as a prognostic score outside of the derivation cohort, with suboptimal statistical calibration and discrimination, particularly in those patients with an intermediate prognosis. Extra-cerebral metastases, leptomeningeal disease, age and potential use of novel targeted agents after brain metastases are diagnosed, should be incorporated into future prognostic models.An improved prognostic score is required to underpin high-quality randomised controlled trials in an area with a wide disparity in clinical care

    Extensive central nervous system involvement in Merkel cell carcinoma: a case report and review of the literature

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    <p>Abstract</p> <p>Introduction</p> <p>Merkel cell carcinoma is a rare malignant cutaneous neoplasm that is locally invasive and frequently metastasizes to lymph nodes, liver, lungs, bone and brain. The incidence of Merkel cell carcinoma has increased in the past three decades.</p> <p>Case presentation</p> <p>A 65-year-old Caucasian man presented with a sudden onset of severe headache and a three-month history of balance disturbance. Magnetic resonance imaging revealed a large meningeal metastasis. The radiologic workup showed retroperitoneal and inguinal lymph node metastases. Biopsy of the inguinal lymph nodes showed metastases of Merkel cell carcinoma. Biopsy from three different suspected skin lesions revealed no Merkel cell carcinoma, and the primary site of Merkel cell carcinoma remained unknown. Leptomeningeal metastases, new axillary lymph node metastases, and intraspinal (epidural and intradural) metastases were detected within six, seven and eight months, respectively, from the start of symptoms despite treating the intracranial metastasis with gamma knife and the abdominal metastases with surgical dissection and external radiotherapy. This indicates the aggressive nature of the disease.</p> <p>Conclusion</p> <p>To the best of our knowledge, this is the first report in the literature of an intracranial meningeal metastasis of Merkel cell carcinoma treated with gamma knife and of intraspinal intradural metastases of Merkel cell carcinoma. Despite good initial response to radiotherapy, recurrence and occurrence of new metastases are common in Merkel cell carcinoma.</p

    Engineering validation for lithium target facility of the IFMIF under IFMIF/EVEDA project

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    The International Fusion Materials Irradiation Facility (IFMIF), presently in the Engineering Validation and Engineering Design Activities (EVEDA) phase was started from 2007 under the frame of the Broader Approach (BA) agreement. In the activities, a prototype Li loop with the world's highest flow rate of 3000L/min was constructed in 2010, and it succeeded in generating a 100mm wide and 25mm thick with a free-surface lithium flow along a concave back plate steadily at a high-speed of 15m/s at 250°C for 1300h. In the demonstration operation it was needed to develop the Li flowing measurement system with precious resolution less than 0.1mm, and a new wave height measuring method which is laser-probe method was developed for measurements of the 3D geometry of the liquid Li target surface. Using the device, the stability of the variation in the Li flowing thickness which is required in the IFMIF specification was ±1mm or less as the liquid Li target, and the result was satisfied with it and the feasibility of the long-term stable liquid Li flow was also verified. The results of the other engineering validation tests such as lithium purification tests of lithium target facility have also been evaluated and summarized
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