A note on the invariant distribution of a quasi-birth-and-death process

The aim of this paper is to give an explicit formula of the invariant distribution of a quasi-birth-and-death process in terms of the block entries of the transition probability matrix using a matrix-valued orthogonal polynomials approach. We will show that the invariant distribution can be computed using the squared norms of the corresponding matrix-valued orthogonal polynomials, no matter if they are or not diagonal matrices. We will give an example where the squared norms are not diagonal matrices, but nevertheless we can compute its invariant distribution

COVID-19 in a mosaic trisomy 13 patient with polycystic kidney disease

A grant from the One-University Open Access Fund at the University of Kansas was used to defray the author's publication fees in this Open Access journal. The Open Access Fund, administered by librarians from the KU, KU Law, and KUMC libraries, is made possible by contributions from the offices of KU Provost, KU Vice Chancellor for Research & Graduate Studies, and KUMC Vice Chancellor for Research. For more information about the Open Access Fund, please see http://library.kumc.edu/authors-fund.xml.Presentation, management, and outcomes of COVID-19 infections among younger patients is an area of medicine with deficits in research, likely due to the lower incidence of severe COVID-19 disease among the younger population. Management can be challenging, and clinicians often guide their decision-making based on the ever-changing protocols that are tailored mostly to the elderly population. Even more underrepresented in COVID-19 research are patients with chromosomal abnormalities and trisomy syndromes, as they appear less frequently, but have risk of increased morbidity and mortality due to underlying medical conditions. We describe a case of severe COVID-19 infection in a young patient with mosaic trisomy 13 and pre-existing polycystic kidney disease, who developed severe acute hypoxic respiratory failure and acute chronic kidney injury. The patient was provided maximal pharmacological support and her clinical course helps to shape the understanding of COVID-19 infections in the setting of chromosomal abnormalities and complex medical history

Existential witness extraction in classical realizability and via a negative translation

We show how to extract existential witnesses from classical proofs using Krivine's classical realizability---where classical proofs are interpreted as lambda-terms with the call/cc control operator. We first recall the basic framework of classical realizability (in classical second-order arithmetic) and show how to extend it with primitive numerals for faster computations. Then we show how to perform witness extraction in this framework, by discussing several techniques depending on the shape of the existential formula. In particular, we show that in the Sigma01-case, Krivine's witness extraction method reduces to Friedman's through a well-suited negative translation to intuitionistic second-order arithmetic. Finally we discuss the advantages of using call/cc rather than a negative translation, especially from the point of view of an implementation.Comment: 52 pages. Accepted in Logical Methods for Computer Science (LMCS), 201

Overcoming Postcommunist Labour Weakness: Attritional and Enabling Effects of MNCs in Central and Eastern Europe

Based on micro-level analysis of the developments in the steel sector in Poland, Romania and Slovakia, this paper examines the effects of multinational corporations (MNCs) on labour unions in Central and Eastern Europe. It makes a three-fold argument. First, it shows that union weakness can be attributed to unions’ strategies during the restructuring and privatization processes of postcommunist transition. Consequently, tactics used for union regeneration in the West are less applicable to CEE. Rather, the overcoming of postcommunist legacy is linked to the power of transnational capital. Through attritional and enabling effects, ownership by MNCs forces the unions to focus their efforts on articulating workers’ interests. The paper examines the emerging system of industrial relations in the sector and explores the development of the capabilities needed to overcome postcommunist legacies

Costs of Biopsy and Complications in Patients with Lung Cancer

PURPOSE: To describe the distribution of diagnostic procedures, rates of complications, and total cost of biopsies for patients with lung cancer. PATIENTS AND METHODS: Observational study using data from IBM Marketscan(®) Databases for continuously insured adult patients with a primary lung cancer diagnosis and treatment between July 2013 and June 2017. Costs of lung cancer diagnosis covered 6 months prior to index biopsy through treatment. Costs of chest CT scans, biopsy, and post-procedural complications were estimated from total payments. Costs of biopsies incidental to inpatient admissions were estimated by comparable outpatient biopsies. RESULTS: The database included 22,870 patients who had a total of 37,160 biopsies, of which 16,009 (43.1%) were percutaneous, 14,997 (40.4%) bronchoscopic, 4072 (11.0%) surgical and 2082 (5.6%) mediastinoscopic. Multiple biopsies were performed on 41.9% of patients. The most common complications among patients receiving only one type of biopsy were pneumothorax (1304 patients, 8.4%), bleeding (744 patients, 4.8%) and intubation (400 patients, 2.6%). However, most complications did not require interventions that would add to costs. Median total costs were highest for inpatient surgical biopsies ($29,988) and lowest for outpatient percutaneous biopsies ($1028). Repeat biopsies of the same type increased costs by 40-80%. Complications account for 13% of total costs. CONCLUSION: Costs of biopsies to confirm lung cancer diagnosis vary substantially by type of biopsy and setting. Multiple biopsies, inpatient procedures and complications result in higher costs

Chaotic Scattering in Heavy--Ion Reactions

We discuss the relevance of chaotic scattering in heavy--ion reactions at energies around the Coulomb barrier. A model in two and three dimensions which takes into account rotational degrees of freedom is discussed both classically and quantum-mechanically. The typical chaotic features found in this description of heavy-ion collisions are connected with the anomalous behaviour of several experimental data.Comment: 35 pages in RevTex (version 3.0) plus 27 PostScript figures obtainable by anonymous ftp from VAXFCT.CT.INFN.IT in directory kaos. Fig. 1 upon request to the authors. To be published in the October Focus issue on chaotic scattering of CHAO