33,547 research outputs found

    Optimal control of a fractional order epidemic model with application to human respiratory syncytial virus infection

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    A human respiratory syncytial virus surveillance system was implemented in Florida in 1999, to support clinical decision-making for prophylaxis of premature newborns. Recently, a local periodic SEIRS mathematical model was proposed in [Stat. Optim. Inf. Comput. 6 (2018), no.1, 139--149] to describe real data collected by Florida's system. In contrast, here we propose a non-local fractional (non-integer) order model. A fractional optimal control problem is then formulated and solved, having treatment as the control. Finally, a cost-effectiveness analysis is carried out to evaluate the cost and the effectiveness of proposed control measures during the intervention period, showing the superiority of obtained results with respect to previous ones.Comment: This is a preprint of a paper whose final and definite form is with 'Chaos, Solitons & Fractals', available from [http://www.elsevier.com/locate/issn/09600779]. Submitted 23-July-2018; Revised 14-Oct-2018; Accepted 15-Oct-2018. arXiv admin note: substantial text overlap with arXiv:1801.0963

    Optimal Control and Sensitivity Analysis of a Fractional Order TB Model

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    A Caputo fractional-order mathematical model for the transmission dynamics of tuberculosis (TB) was recently proposed in [Math. Model. Nat. Phenom. 13 (2018), no. 1, Art. 9]. Here, a sensitivity analysis of that model is done, showing the importance of accuracy of parameter values. A fractional optimal control (FOC) problem is then formulated and solved, with the rate of treatment as the control variable. Finally, a cost-effectiveness analysis is performed to assess the cost and the effectiveness of the control measures during the intervention, showing in which conditions FOC is useful with respect to classical (integer-order) optimal control.Comment: This is a preprint of a paper whose final and definite form is with 'Statistics Opt. Inform. Comput.', Vol. 7, No 2 (2019). See [http://www.IAPress.org]. Submitted 09/Sept/2018; Revised 10/Dec/2018; Accepted 11/Dec/2018. arXiv admin note: text overlap with arXiv:1801.09634, arXiv:1810.0690

    Neutrino masses and baryogenesis in SO(10) unified theories

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    We report on some phenomenological implications of a class of unified models based on SO(10) gauge group, with intermediate symmetry group containing SU(2)_R. Interesting predictions for neutrino masses are discussed, which are relevant both for solar neutrino and dark matter problems, as well as a model for the formation of the baryon asymmetry of the universe required by primordial nucleosynthesis.Comment: Latex 16 pages, 1 ps figure. Appeared in Proceedings of seventh International Workshop on Neutrino Telescopes, Venezia February 27 - March 1 1996, Editor M. Baldo Ceoli

    Estimative for the size of the compactification radius of a one extra dimension Universe

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    In this work, we use the Casimir effect to probe the existence of one extra dimension. We begin by evaluating the Casimir pressure between two plates in a M4×S1M^4\times S^1 manifold, and then use an appropriate statistical analysis in order to compare the theoretical expression with a recent experimental data and set bounds for the compactification radius

    Analysis of unmitigated large break loss of coolant accidents using MELCOR code

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    In the framework of severe accident research activity developed by ENEA, a MELCOR nodalization of a generic Pressurized Water Reactor of 900 MWe has been developed. The aim of this paper is to present the analysis of MELCOR code calculations concerning two independent unmitigated large break loss of coolant accident transients, occurring in the cited type of reactor. In particular, the analysis and comparison between the transients initiated by an unmitigated double-ended cold leg rupture and an unmitigated double-ended hot leg rupture in the loop 1 of the primary cooling system is presented herein. This activity has been performed focusing specifically on the in-vessel phenomenology that characterizes this kind of accidents. The analysis of the thermal-hydraulic transient phenomena and the core degradation phenomena is therefore here presented. The analysis of the calculated data shows the capability of the code to reproduce the phenomena typical of these transients and permits their phenomenological study. A first sequence of main events is here presented and shows that the cold leg break transient results faster than the hot leg break transient because of the position of the break. Further analyses are in progress to quantitatively assess the results of the code nodalization for accident management strategy definition and fission product source term evaluation

    Ect2/Pbl Acts via Rho and Polarity Proteins to Direct the Assembly of an Isotropic Actomyosin Cortex upon Mitotic Entry.

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    Entry into mitosis is accompanied by profound changes in cortical actomyosin organization. Here, we delineate a pathway downstream of the RhoGEF Pbl/Ect2 that directs this process in a model epithelium. Our data suggest that the release of Pbl/Ect2 from the nucleus at mitotic entry drives Rho-dependent activation of Myosin-II and, in parallel, induces a switch from Arp2/3 to Diaphanous-mediated cortical actin nucleation that depends on Cdc42, aPKC, and Par6. At the same time, the mitotic relocalization of these apical protein complexes to more lateral cell surfaces enables Cdc42/aPKC/Par6 to take on a mitosis-specific function-aiding the assembly of a relatively isotropic metaphase cortex. Together, these data reveal how the repolarization and remodeling of the actomyosin cortex are coordinated upon entry into mitosis to provide cells with the isotropic and rigid form they need to undergo faithful chromosome segregation and division in a crowded tissue environment

    Changing the University System Management: a study of the Italian scenario

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    Over recent years, the Italian University System has been handling a phase of deep changes, which have had significant impact on its mission and on the way it operates. The most important of these changes have been to the organisation of universities, their recruitment procedures and in terms of improvements to the quality and efficiency of the university system itself. In this perspective, the objective of this research was to carry out a critical analysis of the process of change, with special reference to improving efficiency by making the transition from cash-based accounting to accrual accounting. In order to achieve this objective, the starting point was the legislation of reference that sets out the terms for the move to financial accrual accounting. A comparative analysis was then carried out at an international level, with the purpose of highlighting the strengths and weaknesses identified during the implementation of these new procedures within the public field. This was followed by an analysis of the details of the theory defining the accounting principles to be used in the process of preparing university’s financial statements. Finally, the study identified the main critical points relating to implementation of the new accounting system, offering, at the same time, several thoughts concerning possible subsequent analyses on this topic
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