How to choose the endorser: An experimental analysis on the effects of fit and notoriety

The present study is focused on the endorser topic following two different paths: firstly, proposing an extension of the theoretical match-up model, enlarge it through two other potential types of consistency: the typicality fit and the imagery fit. Secondly, the present study aims verifies the applicability of the same framework to the emerging situation with a brand linked to a not well-known endorser (internal as the founder or external as a web influencer). An experimental 3*2 (fit typology*high/low notoriety) between subject analysis was conducted in the food service domain. It showed some interesting considerations.From a theoretical point of view, the first relevant finding is that endorsement might be assimilated to a co-branding strategy, confirming the match-up model as an effective theoretical framework in this domain as well, with significant differences among the three fit typologies investigated. The typicality fit reveals to be the less effective in increasing attitude and other behavioural effects on consumers in spite of the large adoption of this kind of fit by companies. Instead, the imagery fit, seems to be the most impactful in terms of positive word of mouth activation and viral communication activities, at the same level at the categorical one. Moreover, the categorical fit induces the wider range of positive effect on the dependent variables (attitudes, willingness to pay and willingness to buy). Another interesting contribution is that the presence of an appropriate fit (in particular the categorical one) is able to compensate the absence of endorser notoriety and, on the average, the usage of a very popular endorser from the same domain of the brand is not necessary more effective in comparison with a not well-known endorser form the same domain. This result is the peak of the present research from a managerial point of view, as it leads to consider the opportunity to support the emerging practices by which companies turn to not well-known people (disclosing the founder, or presenting some workers, or adopting a common consumer as an influencer). The endorser not well-known, but presented with an adequate story-telling might be the best choice: less onerous and more effective than a big unrelated celebrity

Combinatorics of lattice paths with and without spikes

We derive a series of results on random walks on a d-dimensional hypercubic lattice (lattice paths). We introduce the notions of terse and simple paths corresponding to the path having no backtracking parts (spikes). These paths label equivalence classes which allow a rearrangement of the sum over paths. The basic combinatorial quantities of this construction are given. These formulas are useful when performing strong coupling (hopping parameter) expansions of lattice models. Some applications are described.Comment: Latex. 25 page

Lagrangian phase transitions in nonequilibrium thermodynamic systems

In previous papers we have introduced a natural nonequilibrium free energy by considering the functional describing the large fluctuations of stationary nonequilibrium states. While in equilibrium this functional is always convex, in nonequilibrium this is not necessarily the case. We show that in nonequilibrium a new type of singularities can appear that are interpreted as phase transitions. In particular, this phenomenon occurs for the one-dimensional boundary driven weakly asymmetric exclusion process when the drift due to the external field is opposite to the one due to the external reservoirs, and strong enough.Comment: 10 pages, 2 figure

Diffusion, super-diffusion and coalescence from single step

From the exact single step evolution equation of the two-point correlation function of a particle distribution subjected to a stochastic displacement field \bu(\bx), we derive different dynamical regimes when \bu(\bx) is iterated to build a velocity field. First we show that spatially uncorrelated fields \bu(\bx) lead to both standard and anomalous diffusion equation. When the field \bu(\bx) is spatially correlated each particle performs a simple free Brownian motion, but the trajectories of different particles result to be mutually correlated. The two-point statistical properties of the field \bu(\bx) induce two-point spatial correlations in the particle distribution satisfying a simple but non-trivial diffusion-like equation. These displacement-displacement correlations lead the system to three possible regimes: coalescence, simple clustering and a combination of the two. The existence of these different regimes, in the one-dimensional system, is shown through computer simulations and a simple theoretical argument.Comment: RevTeX (iopstyle) 19 pages, 5 eps-figure

Fluctuations in Stationary non Equilibrium States

In this paper we formulate a dynamical fluctuation theory for stationary non equilibrium states (SNS) which covers situations in a nonlinear hydrodynamic regime and is verified explicitly in stochastic models of interacting particles. In our theory a crucial role is played by the time reversed dynamics. Our results include the modification of the Onsager-Machlup theory in the SNS, a general Hamilton-Jacobi equation for the macroscopic entropy and a non equilibrium, non linear fluctuation dissipation relation valid for a wide class of systems

Stochastic interacting particle systems out of equilibrium

This paper provides an introduction to some stochastic models of lattice gases out of equilibrium and a discussion of results of various kinds obtained in recent years. Although these models are different in their microscopic features, a unified picture is emerging at the macroscopic level, applicable, in our view, to real phenomena where diffusion is the dominating physical mechanism. We rely mainly on an approach developed by the authors based on the study of dynamical large fluctuations in stationary states of open systems. The outcome of this approach is a theory connecting the non equilibrium thermodynamics to the transport coefficients via a variational principle. This leads ultimately to a functional derivative equation of Hamilton-Jacobi type for the non equilibrium free energy in which local thermodynamic variables are the independent arguments. In the first part of the paper we give a detailed introduction to the microscopic dynamics considered, while the second part, devoted to the macroscopic properties, illustrates many consequences of the Hamilton-Jacobi equation. In both parts several novelties are included.Comment: 36 page

A non-perturbative Lorentzian path integral for gravity

A well-defined regularized path integral for Lorentzian quantum gravity in three and four dimensions is constructed, given in terms of a sum over dynamically triangulated causal space-times. Each Lorentzian geometry and its associated action have a unique Wick rotation to the Euclidean sector. All space-time histories possess a distinguished notion of a discrete proper time. For finite lattice volume, the associated transfer matrix is self-adjoint and bounded. The reflection positivity of the model ensures the existence of a well-defined Hamiltonian. The degenerate geometric phases found previously in dynamically triangulated Euclidean gravity are not present. The phase structure of the new Lorentzian quantum gravity model can be readily investigated by both analytic and numerical methods.Comment: 11 pages, LaTeX, improved discussion of reflection positivity, conclusions unchanged, references update

Macroscopic fluctuation theory

Stationary non-equilibrium states describe steady flows through macroscopic systems. Although they represent the simplest generalization of equilibrium states, they exhibit a variety of new phenomena. Within a statistical mechanics approach, these states have been the subject of several theoretical investigations, both analytic and numerical. The macroscopic fluctuation theory, based on a formula for the probability of joint space-time fluctuations of thermodynamic variables and currents, provides a unified macroscopic treatment of such states for driven diffusive systems. We give a detailed review of this theory including its main predictions and most relevant applications.Comment: Review article. Revised extended versio

Concomitant Renal Artery and Aortic Aneurysm: Is Endovascular Surgery the Correct Approach?

Our case illustrates the concomitant presence of a giant aneurysm of the left renal artery at the ostium and an abdominal aortic aneurysm, in presence of a complex aortic anatomy. Type of approach and timing of the treatment is still not well established for the rare coexistence of these 2 pathologies. In case of surgical high-risk patients, endovascular therapy is considered now the best choice to exclude arterial and aortic aneurysms although there are chances to do further interventions in the follow-up. For this reason, we simultaneously treated both the aneurysms through an embolization with plugs and coils of renal aneurysm and endovascular exclusion of aortic aneurysm; in the follow-up, renal function of the patient worsened until hemodialysis and we saw the reperfusion of renal aneurysm and the onset of endoleak I type A from above the aortic and renal aneurysm and B from iliac legs of the previous endograft. We performed a parallel graft technique on visceral vessels to exclude the refilling of both aneurysms and preserve visceral vascularization. Follow-up at 12 months showed the complete exclusion of the aneurysms and the patency of stents in celiac trunk and superior mesenteric artery

Current Renormalisation Constants with an O(a)-improved Fermion Action

Using chiral Ward identities, we determine the renormalisation constants of bilinear quark operators for the Sheikholeslami-Wohlert action lattice at beta=6.2. The results are obtained with a high degree of accuracy. For the vector current renormalisation constant we obtain Z_V=0.817(2)(8), where the first error is statistical and the second is due to mass dependence of Z_V. This is close to the perturbative value of 0.83. For the axial current renormalisation constant we obtain Z_A = 1.045(+10 -14), significantly higher than the value obtained in perturbation theory. This is shown to reduce the difference between lattice estimates and the experimental values for the pseudoscalar meson decay constants, but a significant discrepancy remains. The ratio of pseudoscalar to scalar renormalisation constants, Z_P/Z_S, is less well determined, but seems to be slightly lower than the perturbative value.Comment: 8 pages uuencoded compressed postscript file. Article to be submitted to Phys.Rev.