The compositional construction of Markov processes II

In an earlier paper we introduced a notion of Markov automaton, together with parallel operations which permit the compositional description of Markov processes. We illustrated by showing how to describe a system of n dining philosophers, and we observed that Perron-Frobenius theory yields a proof that the probability of reaching deadlock tends to one as the number of steps goes to infinity. In this paper we add sequential operations to the algebra (and the necessary structure to support them). The extra operations permit the description of hierarchical systems, and ones with evolving geometry

Quantum harmonic oscillator with superoscillating initial datum

In this paper we study the evolution of superoscillating initial data for the quantum driven harmonic oscillator. Our main result shows that superoscillations are amplified by the harmonic potential and that the analytic solution develops a singularity in finite time. We also show that for a large class of solutions of the Schr\"odinger equation, superoscillating behavior at any given time implies superoscillating behavior at any other time.Comment: 12 page

The Economic Burden of Biological Therapy in Rheumatoid Arthritis in Clinical Practice: Cost-Effectiveness Analysis of Sub-Cutaneous Anti-TNFα Treatment in Italian Patients:

Rheumatoid arthritis (RA), with a prevalence of 0.46%, is found in about 272,004 patients in Italy. The socioeconomic cost of rheumatoid arthritis in Italy in 2002 has been estimated at €1,600 million. Cost-effectiveness evaluations have been based on the concept that, with treatment, patients will not progress to the next level(s) of disease severity or will take a longer time to progress, thus avoiding or delaying the high costs and low utility associated with more severe disease. Many cost-effective studies have been based on the variation of Health Assessment Questionnaire (HAQ) in clinical trials. The objective of this study is to perform a cost-effective analysis of 86 patients with rheumatoid arthritis in therapy with adalimumab 40 mg every other week and etanercept 50 mg/week for two years in a population of patients observed in clinical practice. The group of patients in therapy with adalimumab had also taken methotrexate, mean dose 12.4±2.5 mg/week (22 patients) or leflunomide 20 mg/day (16 patients). The group of patients in therapy with etanercept had also taken methotrexate, mean dose 11.7±2.6 mg/week (24 patients) or leflunomide 20 mg/day (24 patients). Incremental costs and QALYs (quality adjusted life years) gains are calculated compared with baseline, assuming that without biologic treatment patients would remain at the baseline level through the year. Conversion HAQ scores to utility were based on the Bansback algorithm. The results after two years showed: in the group methotrexate+adalimumab the QALY gained was 0.62±0.15 with a treatment cost of €26,517.62 and a QALY/cost of €42,521.13. In the group methotrexate+etanercept the QALY gained was 0.64±0.26 with a treatment cost of €25,020.96 and a QALY/cost of €39,171.76. The result of using etanercept in association with methotrexate is cost-effectiveness with a QALY gained under the acceptable threshold of €50,000. These are important data for discussion from an economic point of view when we choose a biologic therapy for rheumatoid arthritis in clinical practice

Scavenging effect of lazaroids U78517F, U74389F, U74500A on oxygen free radicals produced by stimulated human polymorphonuclear leucocytes and by chemical method

Authors investigated the scavenger capability of lazaroids, a new group of compounds (21-aminosteroid) that are reported in the literature to have interesting anti-lipid peroxidation properties. Authors tested the degree of scavenger activity related to the oxygen derived free radicals (ODFR) with different methods: 1) chemiluminescence; 2) production of superoxide anion from activated polymorphonuclear cells; 3) production of hydroxyl radical through a chemical procedure. Results showed a global scavenger activity of the three lazaroids (U78517F, U74389F, U74500A) in all the various tests, but differences of intensity of their action were noted among in each compound. We can thus attribute to these compounds a scavenger activity on the oxygen free radicals; this activity may facilitate their already known anti-lipid peroxidation action. Therefore, clinical use of lazaroids can be hypothesized for the diseases in which inflammation plays an important pathogenetic role via the production of oxygen free radicals and the resulting lipid peroxidation associated with tissue damage

Sea-level constraints on the amplitude and source distribution of Meltwater Pulse 1A.

During the last deglaciation, sea levels rose as ice sheets retreated. This climate transition was punctuated by periods of more intense melting; the largest and most rapid of these—Meltwater Pulse 1A—occurred about 14,500 years ago, with rates of sea-level rise reaching approximately 4 m per century1, 2, 3. Such rates of rise suggest ice-sheet instability, but the meltwater sources are poorly constrained, thus limiting our understanding of the causes and impacts of the event4, 5, 6, 7. In particular, geophysical modelling studies constrained by tropical sea-level records1, 8, 9 suggest an Antarctic contribution of more than seven metres, whereas most reconstructions10 from Antarctica indicate no substantial change in ice-sheet volume around the time of Meltwater Pulse 1A. Here we use a glacial isostatic adjustment model to reinterpret tropical sea-level reconstructions from Barbados2, the Sunda Shelf3 and Tahiti1. According to our results, global mean sea-level rise during Meltwater Pulse 1A was between 8.6 and 14.6 m (95% probability). As for the melt partitioning, we find an allowable contribution from Antarctica of either 4.1 to 10.0 m or 0 to 6.9 m (95% probability), using two recent estimates11, 12 of the contribution from the North American ice sheets. We conclude that with current geologic constraints, the method applied here is unable to support or refute the possibility of a significant Antarctic contribution to Meltwater Pulse 1A

Schur functions and their realizations in the slice hyperholomorphic setting

we start the study of Schur analysis in the quaternionic setting using the theory of slice hyperholomorphic functions. The novelty of our approach is that slice hyperholomorphic functions allows to write realizations in terms of a suitable resolvent, the so called S-resolvent operator and to extend several results that hold in the complex case to the quaternionic case. We discuss reproducing kernels, positive definite functions in this setting and we show how they can be obtained in our setting using the extension operator and the slice regular product. We define Schur multipliers, and find their co-isometric realization in terms of the associated de Branges-Rovnyak space