212 research outputs found

    Hamiltonian and Potentials in Derivative Pricing Models: Exact Results and Lattice Simulations

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    The pricing of options, warrants and other derivative securities is one of the great success of financial economics. These financial products can be modeled and simulated using quantum mechanical instruments based on a Hamiltonian formulation. We show here some applications of these methods for various potentials, which we have simulated via lattice Langevin and Monte Carlo algorithms, to the pricing of options. We focus on barrier or path dependent options, showing in some detail the computational strategies involved.Comment: 27 pages, 11 figures 1 subsection added (4.1). Slightly longer appendi

    Influence of the customs instruments on implementating the common agricultural policy in the Eurasian economic union

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    The article analyses characteristics of the participation of the Eurasian Economic Union's (EAEU) member states in the World Trade Organization (WTO) and its impact on the Eurasian economic integration. We described the contradictions in the regulatory frameworks between the WTO agreements and regional trade agreements. Moreover, we offered the ways to overcome these contradictions. We demonstrated the role of the economic and legal exemptions that operate on the EAEU's domestic agrarian market in connection with the accession of Russia and Kazakhstan to the WTO. On the one hand, these exemptions were shaped under the influence of tariff commitments made by Russia in the field of agriculture. On the other hand, they were formed due to Kazakhstan's subsequent entry into the WTO and the discrepancy of its tariff obligations for agricultural products with Russia's tariff obligations in the conditions of functioning of the EAEU's common customs tariff. We explored Kazakhstan's tariff commitments to the WTO. We have proved that for the EAEU's further effective development, its participants need to initiate compensation negotiations with other WTO members in order to equalize the overall level of the import duties on the EAEU territory. The study's results can be applied for harmonization of the tariff rates of the EAEU members. It is necessary for achieving the most effective joint economic development and implementing the coordinated foreign trade policy in various economic sectors, including agro-industrial policy and agricultural development of the EAEU states. © 2019 Kovalev V. E., Falchenko O. D., Linetsky A. F., Tarasov A. G. Text.The article has been prepared at the Ural State Economic University with the support of Russian Foundation for Basic Research, the grant No. 18-010-01209 A Forming the organizational and economic model of managing the customs effects of the Eurasian econ

    Institutional factor in international economic activity of region and its socio-economic development

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    The article substantiates the impact of the institutional factor on the development of regional international economic relations. The scope of the study is regional international economic activity (IEA), the subject-matter is the role of the institutional factor in its development. The study purpose is to develop a scientific approach for the assessment of the institutional factor impact on the development of region's international economic relations. The hypothesis is that the targeted efforts of all participants of IEA of the region (business, authorities, local community) to strengthen of theese components of the institutional factor, which have a strong influence on the regional socio-economic development. A methodological approach for the assessment of this influenceis developed. It includes determining three elements of IEA institutionalization - agreements, organizations, events. A three-dimensional model is proposed for the coordination of these elements with 3 groups of countries - developed, developing and CIS, including the Eurasian Economic Union, and also with basic indexes characterizing the qualitative and quantitative contribution of region's IEA into its socio-economic development. This model is tested on the example of the Sverdlovsk region of Russia for 2003-2015. That has allowed to define various kinds of the effects from strenthening the IEA institutional component, which are expressed in the increase of the export of the region, improvement of its investment attractiveness, the diversification of regional economy as well as the the generation of additional jobs and tax flows increase. © Copyright 2005-2016 Institute of Economics, the Ural branch of the RAS. All rights reserved

    Intracochlear schwannoma presenting as diffuse cochlear enhancement: diagnostic challenges of a rare cause of deafness

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    Intracochlear schwannoma is a rare, treatable, cause of unilateral hearing loss. Due to the small size, position, and variable clinical and imaging features, diagnosis presents a significant challenge and is often delayed. We present a case of a patient with an intracochlear schwannoma presenting as a diffuse enhancement of the cochlea, mimicking an infectious or inflammatory process. The absence of focal nodularity in this lesion on multiple high-resolution MRI examinations led to a delay of over 3 years from the patient’s initial presentation to surgical diagnosis. Clinical history and examination, imaging features, pathologic findings, and surgical management options are described

    Bessel Process and Conformal Quantum Mechanics

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    Different aspects of the connection between the Bessel process and the conformal quantum mechanics (CQM) are discussed. The meaning of the possible generalizations of both models is investigated with respect to the other model, including self adjoint extension of the CQM. Some other generalizations such as the Bessel process in the wide sense and radial Ornstein- Uhlenbeck process are discussed with respect to the underlying conformal group structure.Comment: 28 Page

    Human pancreatic islet transplantation: an update and description of the establishment of a pancreatic islet isolation laboratory

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    Type 1 diabetes mellitus (T1DM) is associated with chronic complications that lead to high morbidity and mortality rates in young adults of productive age. Intensive insulin therapy has been able to reduce the likelihood of the development of chronic diabetes complications. However, this treatment is still associated with an increased incidence of hypoglycemia. In patients with "brittle T1DM", who have severe hypoglycemia without adrenergic symptoms (hypoglycemia unawareness), islet transplantation may be a therapeutic option to restore both insulin secretion and hypoglycemic perception. The Edmonton group demonstrated that most patients who received islet infusions from more than one donor and were treated with steroid-free immunosuppressive drugs displayed a considerable decline in the initial insulin independence rates at eight years following the transplantation, but showed permanent C-peptide secretion, which facilitated glycemic control and protected patients against hypoglycemic episodes. Recently, data published by the Collaborative Islet Transplant Registry (CITR) has revealed that approximately 50% of the patients who undergo islet transplantation are insulin independent after a 3-year follow-up. Therefore, islet transplantation is able to successfully decrease plasma glucose and HbA1c levels, the occurrence of severe hypoglycemia, and improve patient quality of life. The goal of this paper was to review the human islet isolation and transplantation processes, and to describe the establishment of a human islet isolation laboratory at the Endocrine Division of the Hospital de Clínicas de Porto Alegre - Rio Grande do Sul, Brazil

    Quantitative analysis of cell composition and purity of human pancreatic islet preparations

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    Author Manuscript 2011 May 1.Despite improvements in outcomes for human islet transplantation, characterization of islet preparations remains poorly defined. This study used both light microscopy (LM) and electron microscopy (EM) to characterize 33 islet preparations used for clinical transplants. EM allowed an accurate identification and quantification of cell types with measured cell number fractions (mean±s.e.m.) of 35.6±2.1% β-cells, 12.6±1.0% non-β-islet cells (48.3±2.6% total islet cells), 22.7±1.5% duct cells, and 25.3±1.8% acinar cells. Of the islet cells, 73.6±1.7% were β-cells. For comparison with the literature, estimates of cell number fraction, cell volume, and extracellular volume were combined to convert number fraction data to volume fractions applicable to cells, islets, and the entire preparation. The mathematical framework for this conversion was developed. By volume, β-cells were 86.5±1.1% of the total islet cell volume and 61.2±0.8% of intact islets (including the extracellular volume), which is similar to that of islets in the pancreas. Our estimates produced 1560±20 cells in an islet equivalent (volume of 150-μm diameter sphere), of which 1140±15 were β-cells. To test whether LM analysis of the same tissue samples could provide reasonable estimates of purity of the islet preparations, volume fraction of the islet tissue was measured on thin sections available from 27 of the clinical preparations by point counting morphometrics. Islet purity (islet volume fraction) of individual preparations determined by LM and EM analyses correlated linearly with excellent agreement (R[superscript 2]=0.95). However, islet purity by conventional dithizone staining was substantially higher with a 20–30% overestimation. Thus, both EM and LM provide accurate methods to determine the cell composition of human islet preparations and can help us understand many of the discrepancies of islet composition in the literature.National Institutes of Health (U.S.) (Grant RO1-DK063108)National Institutes of Health (U.S.) (Grant NCRR ICR U4Z RR 16606)Joslin Diabetes and Endocrinology Research Center (Grant DK36836)Diabetes Research & Wellness FoundationJuvenile Diabetes Research Foundation International (Islet Transplantation, Harvard Medical School

    Enumeration of islets by nuclei counting and light microscopic analysis

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    Author Manuscript 2011 May 1.Islet enumeration in impure preparations by conventional dithizone staining and visual counting is inaccurate and operator dependent. We examined nuclei counting for measuring the total number of cells in islet preparations, and we combined it with morphological analysis by light microscopy (LM) for estimating the volume fraction of islets in impure preparations. Cells and islets were disrupted with lysis solution and shear, and accuracy of counting successively diluted nuclei suspensions was verified with (1) visual counting in a hemocytometer after staining with crystal violet, and automatic counting by (2) aperture electrical resistance measurement and (3) flow cytometer measurement after staining with 7-aminoactinomycin-D. DNA content averaged 6.5 and 6.9 pg of DNA per cell for rat and human islets, respectively, in agreement with literature estimates. With pure rat islet preparations, precision improved with increasing counts, and samples with about greater than or equal to 160 islets provided a coefficient of variation of about 6%. Aliquots of human islet preparations were processed for LM analysis by stereological point counting. Total nuclei counts and islet volume fraction from LM analysis were combined to obtain the number of islet equivalents (IEs). Total number of IE by the standard method of dithizone staining/manual counting was overestimated by about 90% compared with LM/nuclei counting for 12 freshly isolated human islet research preparations. Nuclei counting combined with islet volume fraction measurements from LM is a novel method for achieving accurate islet enumeration.National Institutes of Health (U.S.) (Grant NCRR ICR U4Z 16606)National Institutes of Health (U.S.) (Grant R01-DK063108-01A1)National Institutes of Health (U.S.) (Grant NCRR ICR U42 RR0023244-01)Joslin Diabetes and Endocrinology Research Center (Grant DK36836)Diabetes Research & Wellness FoundationJuvenile Diabetes Research Foundation International (Islet Transplantation, Harvard Medical School
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