Arithmetic properties of curves and Jacobians

2020 Fall.Includes bibliographical references.This thesis is about algebraic curves and their Jacobians. The first chapter concerns Abhyankar's Inertia Conjecture which is about the existence of unramified covers of the affine line in positive characteristic with prescribed ramification behavior. The second chapter demonstrates the existence of a curve C for which a particular algebraic cycle, called the Ceresa cycle, is torsion in the Jacobian variety of C. The final chapter is a study of supersingular Hurwitz curves in positive characteristic

Designing international public sector accounting standards: An analysis of constituents’ participation through comment letters

Harmonization of public sector accounting is attracting increasing attention from scholars and practitioners. A focal component of this phenomenon is the setting of accounting standards, whose legitimacy is paramount to their application. As participation by constituents is considered fundamental for ensuring this legitimacy, in this study, we focus on participation through comment letters in the due process. In particular, we explore the type of respondents, their geographical area, their agreement/disagreement with the documents prepared by the International Public Sector Accounting Standards Board (IPSASB) and the issues of importance to them, through an analysis of the comment letters submitted for six projects launched over the period 2017–2020 by the IPSASB. Furthermore, we analyze some factors that may affect countries’ participation in the due process. The analysis enriches our understanding of the IPSASB’s due process and provides relevant insights for the growing research into accounting standard-setting

Veno-occlusive disease of the liver in children treated for Wilms tumor

Hepatotoxicity consistent with the clinical diagnosis of veno-occlusive disease (VOD) of the liver has been suspected after conventional anti-cancer chemotherapy in children. To establish the incidence of hepatotoxicity and its relationship with VOD, we analyzed toxicity data obtained on 511 children affected by Wilms tumor and treated according to the SIOP-9 protocol. They all received pre- and postnephrectomy chemotherapy using dactinomycin (AD) and vincristine (VCR) +/- other drugs +/- radiotherapy according to surgical stage and histology. Sixty-four patients suffered at least one episode of hepatotoxicity and 41 satisfied the criteria for a clinical diagnosis of VOD. In this latter group, toxicity occurred during preoperative treatment in 15 patients and was confirmed histopathologically in 9 of the 16 liver biopsies obtained. There was a higher percentage of children aged less than 1 year at diagnosis in the VOD group than in the other patients (24% vs. 11.4%). The degree of liver damage in the younger patients seems important, as suggested by a higher increase in transaminases. VOD developed in 12% of the 68 irradiated children vs. 7% in the non-irradiated group. Statistical analysis showed an increased risk of VOD in younger patients (p < 0.001) and in those receiving radiotherapy (p < 0.001). All patients recovered after 6-180 days using supportive therapy only. (1) 8% of children treated according to the SIOP-9 protocol, developed hepatotoxicity consistent with VOD. Excluding patients who received radiotherapy, the incidence was 6%. These figures are much higher than in earlier reports, though different diagnostic criteria were used. (2) Chemotherapy with AD and VCR seems to be a major cause of VOD. (3) Risk factors are young age and concomitant radiotherapy. (4) VOD does not prejudice positive outcome for these patient

Salvage rates and prognostic factors after relapse in children and adolescents with initially localised synovial sarcoma

Background: Previous studies have reported a poor outcome for synovial sarcoma patients whose tumours relapse. Methods: This study analysed 44 relapsing cases in a series of 118 consecutive patients&lt;21 yr of age with non-metastatic synovial sarcoma prospectively enrolled in Italian paediatric protocols between 1979 and 2006. In an effort to identify a possible risk-adapted stratification enabling a better planning of second-line treatment, the relapsing patients' outcome was analysed vis-à-vis their clinical picture at onset, first-line treatments, clinical findings at the time of first relapse and second-line treatment modalities. Results: The first event was a local recurrence in only 15 cases, and metastatic in 29 (associated with local relapse too in 7 cases). The time to relapse ranged from 4 to 108 months (median 20 months). Overall survival was 29.7% and 21.0% five and ten years after relapsing, respectively. The variables influencing survival were the timing and type of relapse (combined) and the chances of a secondary remission, which correlated strongly with the feasibility of complete surgery. Conclusions: Our study confirmed a largely unsatisfactory prognosis after recurrences in children and adolescents with synovial sarcoma: the chances of survival can be estimated on the basis of several variables for the purposes of planning risk-adapted salvage protocols. An aggressive surgical approach should be recommended. New effective systemic agents are warranted, and experimental therapies can be offered to patients with little chance of salvage. © 2012 Elsevier Ltd. All rights reserved

Renal cell carcinoma in children: A clinicopathologic study

Purpose: To identify the prognostic factors, treatment, and outcome of children affected by renal cell carcinoma (RCC). Patients and Methods: The series included 41 patients (18 males and 23 females) with a median age of 124 months observed at the 11 Italian Association for Pediatric Hematology and Oncology centers from January 1973 to January 2001. Clinical data, surgical notes, pathologic findings, and summaries of therapy were taken from the charts. Results: Seven (17%) of the 41 patients had a papillary histology, and 34 (82.4%) had nonpapillary histology. Eighteen patients (43.9%) had stage I, one patient (2.4%) had stage II, two patients (4.8%) had stage IIIA, 10 patients (24.3%) had stage IIIB, and nine patients (21.9%) had stage IV disease. One patient had a bilateral involvement at diagnosis. Seven patients experienced disease recurrence. Lung and liver were the most common distant lesions and usually were fatal. In this study, the major factor influencing the prognosis was the stage. Event-free survival at 20 years was 53.5% for all patients. Overall survival at 20 years was 54.9% for all patients. Conclusion: RCC is a rare disease in children and adolescents. This neoplasm has a different clinical presentation in children compared with adults but the same outcome. In our experience, patients with localized disease could be cured by nephrectomy alone. Prospective studies in a larger number of patients are needed to confirm radiation therapy and biologic response modifiers as effective adjunct therapy in RCC stage III. The alternative therapy seems warranted in patients with advanced disease. © 2003 by American Society of Clinical Oncology

Quantitative Measurable Concepts to Visualize Business Process Improvement

Business process improvement evaluation enables performance indicators to be used alongside process improvement techniques in order to quantitatively compare measurement information between the as-is and to-be processes. Limitations of the present methods of business process improvement indicate there is scope for looking at the problem in a different way. Business processes are commonly modelled as diagrams which at their fundamental level are complex networks. This suggests the question as to whether complex network analysis (CNA) has anything to contribute to business process improvement. We develop a technique of projecting a business process model onto the sub-space of a complex network and identify the measurable concepts that can be useful in business process improvement. The measurable concepts from CNA are combined with Time and Cost metrics from the simulation technique to visualize and track improvement efforts and satisfy improvement requirements