25 research outputs found

    Lang's conjecture and sharp height estimates for the elliptic curves y2=x3+by^{2}=x^{3}+b

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    For Eb:y2=x3+bE_{b}: y^{2}=x^{3}+b, we establish Lang's conjecture on a lower bound for the canonical height of non-torsion points along with upper and lower bounds for the difference between the canonical and logarithmic height. In many cases, our results are actually best-possible.Comment: published version, incorporates referee's changes as well as other improvement

    Lang's Conjecture and Sharp Height Estimates for the elliptic curves y2=x3+axy^{2}=x^{3}+ax

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    For elliptic curves given by the equation Ea:y2=x3+axE_{a}: y^{2}=x^{3}+ax, we establish the best-possible version of Lang's conjecture on the lower bound of the canonical height of non-torsion points along with best-possible upper and lower bounds for the difference between the canonical and logarithmic height.Comment: published version. Lemmas 5.1 and 6.1 now precise (with resultant refinement to Theorem 1.2). Small corrections to

    小児生体肝移植後のhepatic venous outflow obstructionに対する経皮的治療の長期成績

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    京都大学0048新制・課程博士博士(医学)甲第18878号医博第3989号新制||医||1008(附属図書館)31829京都大学大学院医学研究科医学専攻(主査)教授 坂井 義治, 教授 坂田 隆造, 教授 平岡 眞寛学位規則第4条第1項該当Doctor of Medical ScienceKyoto UniversityDFA

    Estimation of slip parameters associated with frictional heating during the 1999 Taiwan Chi-Chi earthquake by vitrinite reflectance geothermometry

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    To estimate the slip parameters and understand the fault lubrication mechanism during the 1999 Taiwan Chi-Chi earthquake, we applied vitrinite reflectance geothermometry to samples retrieved from the Chelungpu fault. We found a marked reflectance anomaly of 1.30% ± 0.21% in the primary slip zone of the earthquake, whereas the reflectances in the surrounding deformed and host rocks were 0.45% to 0.77%. By applying a kinetic model of vitrinite thermal maturation together with a one-dimensional heat and thermal diffusion equation, we determined the shear stress and peak temperature in the slip zone during the earthquake to be 1.00 ± 0.04 MPa and 626°C ± 25°C, respectively. Taking into account the probable overestimation of the temperature owing to a mechanochemically enhanced reaction or flash heating at grain contacts, this temperature should be considered an upper limit. The lower limit was previously constrained to 400°C by studies of fluid-mobile trace-element concentrations and magnetic minerals. Therefore, we inferred that the peak temperature during the Chi-Chi earthquake was 400°C to 626°C, corresponding to an apparent friction coefficient of 0.01 to 0.06. Such low friction and the previous evidence of a high-temperature fluid suggest that thermal pressurization likely contributed to dynamic weakening during the Chi-Chi earthquake.This study was supported by a Japan Ministry of Education, Culture, Sports, Science and Technology Grant-in-Aid for Young Scientists (A) 23684039, 2013

    Local Prognosis of Patients with Papillary Thyroid Carcinoma who were Intra-operatively Diagnosed as Having Minimal Invasion of the Trachea: A 17-year Experience in a Single Institute

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    BackgroundSince papillary thyroid carcinoma (PTC) with tracheal invasion shows a worse prognosis, aggressive surgical treatment including airway resection has been recommended. However, little is known about local recurrence of PTC with minimal tracheal invasion after shaving or laminated resection of the tracheal cartilage. In this study, we investigated the local prognosis of patients who were intra-operatively diagnosed as having minimal tracheal invasion.MethodsOf 6,015 patients who underwent initial surgery for PTC between 1987 and 2004, 127 (2.1%) were intra-operatively suspected of having minimal invasion to the trachea and underwent shaving or laminated resection of the tracheal cartilage. These 127 patients were enrolled in this study.ResultsOf 127 patients, 107 were intra-operatively regarded as having received macroscopically curative treatment (curative group), whereas minimal carcinoma remnants were suspected in the remaining 20 patients (suspicious group). To date, six patients (4.6%) (one patient in the curative group and five in the suspicious group) showed local recurrence at the tracheal edge. The local disease-free survival of patients in the curative group was better than that of those in the suspicious group (p = 0.0007), although the cause-specific survival of patients in the two groups did not differ. Cut surfaces of resected carcinoma were also pathologically examined for 119 patients and 58 (48.7%) were diagnosed as carcinoma-positive, but the cut surface status was not related to macroscopic curative treatment. Of six patients showing local recurrence, only one died of lung metastasis of carcinoma.ConclusionThe incidence of local recurrence of PTC with minimal tracheal invasion is low at 4.6%. Although this event might not be immediately life-threatening for patients, to improve local prognosis, local curative treatment should be pursued. In cases that are suspected of persistent carcinoma remnants, further shaving or laminated dissection should be performed, and if the carcinoma remnant cannot be eliminated, tracheal fenestration should be considered, although such high-risk tumours may be likely to recur regardless of surgical radicality
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