On Geometric Quantum Confinement in Grushin-type Manifolds

We study the problem of so-called geometric quantum confinement in a class of two-dimensional incomplete Riemannian manifold with metric of Grushin type. We employ a constant-fibre direct integral scheme, in combination with Weyl's analysis in each fibre, thus fully characterising the regimes of presence and absence of essential self-adjointness of the associated Laplace-Beltrami operator.Comment: 16 pages, 2 figure

The International Debate of Business Combination in Public Sector: The Role of IPSAS 40

Practice and Academy have recently involved in the accounting of business combination in the public sector representing a debated topic at national and international levels; in part, by reason of the reorganization action being aimed at rationalizing the public expenditure, on the other hand due to the logic (always in the key resource optimization) modification of territorial composition of territorial entities, as is happening in many countries with the merger of the municipalities. The contribution is based on a critical analysis of the content of IPSAS 40 providing all the approaches for accounting recognition of business combination in public sectors in order to assess whether IPSASB will determine a higher harmonization in this field. In this context, IPSASB has positively orientated the efforts towards the definition of an accepted accounting policy. Keywords: IPSAS 40, Public Sector, Business Combination, Conceptual pape

The Process of Implementing the Accounting Harmonisation In The Italian Local Governments: The Case of Prato

The purpose of this paper is to describe the experience of the Municipality of Prato (Comune di Prato) in adopting the new accounting model proposed by the harmonisation process of local governments. According to the theoretical model developed by institutional theories, the implementation of accounting reforms is connected to external stimuli that are exercised on an organization, and by the capability to interpret and implement the principles and requirements included in reforms. In accordance with the literature, the paper describes the process of implementation of the reform carried out by the Municipality of Prato, assessing the external and internal elements that have influenced the implementation. The paper analyses the most significant conditions and reactions to the change during the experimentation, which should introduce the reform. In this two year period, the new adopter has the chance to play a pro-active role in the process. This circumstance contributes to the development of the research, as it adds a component (the pro-active role), that has not been considered by the literature

Computation of stochastic background from extreme mass ratio inspiral populations for LISA

Extreme mass ratio inspirals (EMRIs) are among the primary targets for the Laser Interferometer Space Antenna (LISA). The extreme mass ratios of these systems result in relatively weak GW signals, that can be individually resolved only for cosmologically nearby sources (up to $z\approx2$). The incoherent piling up of the signal emitted by unresolved EMRIs generate a confusion noise, that can be formally treated as a stochastic GW background (GWB). In this paper, we estimate the level of this background considering a collection of astrophysically motivated EMRI models, spanning the range of uncertainties affecting EMRI formation. To this end, we employed the innovative Augmented Analytic Kludge waveforms and used the full LISA response function. For each model, we compute the GWB SNR and the number of resolvable sources. Compared to simplified computations of the EMRI signals from the literature, we find that for a given model the GWB SNR is lower by a factor of $\approx 2$ whereas the number of resolvable sources drops by a factor 3-to-5. Nonetheless, the vast majority of the models result in potentially detectable GWB which can also significantly contribute to the overall LISA noise budget in the 1-10 mHz frequency range

Geometric confinement and dynamical transmission of a quantum particle in Grushin cylinder

We classify the self-adjoint realisations of the Laplace-Beltrami operator minimally defined on an infinite cylinder equipped with an incomplete Riemannian metric of Grushin type, in the non-trivial class of metrics yielding an infinite deficiency index. Such realisations are naturally interpreted as Hamiltonians governing the geometric confinement of a Schr\"{o}dinger quantum particle away from the singularity, or the dynamical transmission across the singularity. In particular, we characterise all physically meaningful extensions qualified by explicit local boundary conditions at the singularity. Within our general classification we retrieve those distinguished extensions previously identified in the recent literature, namely the most confining and the most transmitting one

Inexact accurate partitioned algorithms for fluid-structure interaction problems with finite elasticity in haemodynamics

In this paper we consider the numerical solution of the three-dimensional fluid–structure interaction problem in haemodynamics, in the case of real geometries, physiological data and finite elasticity vessel deformations. We study some new inexact schemes, obtained from semi-implicit approximations, which treat exactly the physical interface conditions while performing just one or few iterations for the management of the interface position and of the fluid and structure non-linearities. We show that such schemes allow to improve the efficiency while preserving the accuracy of the related exact (implicit) scheme. To do this we consider both a simple analytical test case and two real cases of clinical interest in haemodynamics. We also provide an error analysis for a simple differential model problem when a BDF method is considered for the time discretization and only few Newton iterations are performed at each temporal instant

MATHICSE Technical Report : Time accurate partitioned\ algorithms for the solution of fluid-structure\ interaction problems in haemodynamics

In this work we deal with the numerical solution of the fluid-structure interaction problem arising in the haemodynamic environment. In particular, we consider BDF and Newmark time discretization schemes, and we study different methods for the treatment of the fluid-structure interface position, focusing on partitioned algorithms for the prescription of the continuity conditions at the fluid-structure interface. We consider explicit and implicit algorithms, and new hybrid methods. We study numerically the performances and the accuracy of these schemes, highlighting the best solutions for haemodynamic applications. We also study numerically their convergence properties with respect to time discretization, by introducing an analytical test case

Both selective and neutral processes drive GC content evolution in the human genome

<p>Abstract</p> <p>Background</p> <p>Mammalian genomes consist of regions differing in GC content, referred to as isochores or GC-content domains. The scientific debate is still open as to whether such compositional heterogeneity is a selected or neutral trait.</p> <p>Results</p> <p>Here we analyze SNP allele frequencies, retrotransposon insertion polymorphisms (RIPs), as well as fixed substitutions accumulated in the human lineage since its divergence from chimpanzee to indicate that biased gene conversion (BGC) has been playing a role in within-genome GC content variation. Yet, a distinct contribution to GC content evolution is accounted for by a selective process. Accordingly, we searched for independent evidences that GC content distribution does not conform to neutral expectations. Indeed, after correcting for possible biases, we show that intron GC content and size display isochore-specific correlations.</p> <p>Conclusion</p> <p>We consider that the more parsimonious explanation for our results is that GC content is subjected to the action of both weak selection and BGC in the human genome with features such as nucleosome positioning or chromatin conformation possibly representing the final target of selective processes. This view might reconcile previous contrasting findings and add some theoretical background to recent evidences suggesting that GC content domains display different behaviors with respect to highly regulated biological processes such as developmentally-stage related gene expression and programmed replication timing during neural stem cell differentiation.</p