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

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

Characterisation and classification of oligometastatic disease : a European Society for Radiotherapy and Oncology and European Organisation for Research and Treatment of Cancer consensus recommendation

Oligometastatic disease has been proposed as an intermediate state between localised and systemically metastasised disease. In the absence of randomised phase 3 trials, early clinical studies show improved survival when radical local therapy is added to standard systemic therapy for oligometastatic disease. However, since no biomarker for the identification of patients with true oligometastatic disease is clinically available, the diagnosis of oligometastatic disease is based solely on imaging findings. A small number of metastases on imaging could represent different clinical scenarios, which are associated with different prognoses and might require different treatment strategies. 20 international experts including 19 members of the European Society for Radiotherapy and Oncology and European Organisation for Research and Treatment of Cancer OligoCare project developed a comprehensive system for characterisation and classification of oligometastatic disease. We first did a systematic review of the literature to identify inclusion and exclusion criteria of prospective interventional oligometastatic disease clinical trials. Next, we used a Delphi consensus process to select a total of 17 oligometastatic disease characterisation factors that should be assessed in all patients treated with radical local therapy for oligometastatic disease, both within and outside of clinical trials. Using a second round of the Delphi method, we established a decision tree for oligometastatic disease classification together with a nomenclature. We agreed oligometastatic disease as the overall umbrella term. A history of polymetastatic disease before diagnosis of oligometastatic disease was used as the criterion to differentiate between induced oligometastatic disease (previous history of polymetastatic disease) and genuine oligometastatic disease (no history of polymetastatic disease). We further subclassified genuine oligometastatic disease into repeat oligometastatic disease (previous history of oligometastatic disease) and de-novo oligometastatic disease (first time diagnosis of oligometastatic disease). In de-novo oligometastatic disease, we differentiated between synchronous and metachronous oligometastatic disease. We did a final subclassification into oligorecurrence, oligoprogression, and oligopersistence, considering whether oligometastatic disease is diagnosed during a treatment-free interval or during active systemic therapy and whether or not an oligometastatic lesion is progressing on current imaging. This oligometastatic disease classification and nomenclature needs to be prospectively evaluated by the OligoCare study

An Isocaloric High-Fat Diet Regulates Partially Genetically Determined Fatty Acid and Carbohydrate Uptake and Metabolism in Subcutaneous Adipose Tissue of Lean Adult Twins

Background: The dysfunction of energy metabolism in white adipose tissue (WAT) induces adiposity. Obesogenic diets that are high in saturated fat disturb nutrient metabolism in adipocytes. This study investigated the effect of an isocaloric high-fat diet without the confounding effects of weight gain on the gene expression of fatty acid and carbohydrate transport and metabolism and its genetic inheritance in subcutaneous (s.c.) WAT of healthy human twins. Methods: Forty-six healthy pairs of twins (34 monozygotic, 12 dizygotic) received an isocaloric carbohydrate-rich diet (55% carbohydrates, 30% fat, 15% protein; LF) for 6 weeks followed by an isocaloric diet rich in saturated fat (40% carbohydrates, 45% fat, 15% protein; HF) for another 6 weeks. Results: Gene expression analysis of s.c. WAT revealed that fatty acid transport was reduced after one week of the HF diet, which persisted throughout the study and was not inherited, whereas intracellular metabolism was decreased after six weeks and inherited. An increased inherited gene expression of fructose transport was observed after one and six weeks, potentially leading to increased de novo lipogenesis. Conclusion: An isocaloric dietary increase of fat induced a tightly orchestrated, partially inherited network of genes responsible for fatty acid and carbohydrate transport and metabolism in human s.c. WAT

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

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