Cybernetics of Value Co-creation

The paradigm shift from value creation to value "co-creation" calls for a deeper grasp of organizational learning in marketing theory. This paper adopts a cybernetic view of the process of value co-creation to shed light on its relevant aspects and to supply a framework to implement operations and strategies to foster this process. Can cybernetics help to better understand the process of value co-creation? Can the Viable System Model (Beer, 1979) be a sound approach to shape a more effective value co-creation process able to achieve higher satisfaction and value? In this theoretical paper we will show how cybernetic can be effectively used to give a positive answer to both questions abov

Customer Satisfaction in the Hotel Industry: A Case Study from Sicily

In order to be successful in the market it is not sufficient to attract new customers managers must concentrate on retaining existing customers implementing effective policies of customer satisfaction and loyalty. In hotel industry customer satisfaction is largely hooked upon quality of service. A management approach focused on customer satisfaction can improve customer loyalty, thus increasing the positive image of the touristic destination. Hence, exploring the importance for customers of hotel attributes in hotel selection is indispensable. Research on the topic of guest satisfaction, which translates into the consideration of whether or not customers will return to a hotel or advise it to other tourists, is pivotal to the success of the hospitality business. Neglecting to pay attention to those hotel attributes considered most important by guests, may lead to negative evaluation of the hotel, thus restricting the chance of repeat patronage. We perform a qualitative analysis of a large hotel in Sicily (IT), the Sporting Club Hotel in the town Cefalù, using the Critical Incident Approach (Hayes, 2008). Through the analysis of this case we evaluate the overall customer satisfaction level for the hotel and for each service supplied. We conclude discussing the result and proposing improvement in customer satisfaction management of the hotel

Geometric expansion of the log-partition function of the anisotropic Heisenberg model

We study the asymptotic expansion of the log-partition function of the anisotropic Heisenberg model in a bounded domain as this domain is dilated to infinity. Using the Ginibre's representation of the anisotropic Heisenberg model as a gas of interacting trajectories of a compound Poisson process we find all the non-decreasing terms of this expansion. They are given explicitly in terms of functional integrals. As the main technical tool we use the cluster expansion method.Comment: 38 page

Structural Simulation of Transcatheter Heart Valve in Transcatheter Heart Valve

The durability of transcatheter heart valves (TAV) remains the main disadvantage of transcatheter heart valve implantation (TAVI) for treating aortic valve stenosis. In this study, we assessed the structural mechanics of TAV-in-TAVI using patient-specific modeling. A parametric analysis highlighted that the outcome of TAV-in-TAV depends on the implanted device position and the planned device to be implanted. Contact pressure evinced the impact of different implantation depth and device size on the TAV-in-TAV. This study may bring new insight in the biomechanical performance of TAV to evaluate options for future interventions when the current TAVs experience device failure

Humoral immunological parameters in Italian patients with oral lichen planus

Serum humoral immunological parameters were determined in 25 patients with atrophic-erosive forms of oral lichen planus (OLP) (Group 1), in 28 patients with reticular-plaque-like lesions of OLP (Group 2) and in 21 healthy patients without oral lesions (Group 3). Comparing patients affected by atrophic-erosive forms of OLP (Group 1) with normal Controls (Group 3), increased levels of serum IgG approaching the statistical significance were found (Kruskal-Wallis test p = 0.0572). It was also found a significantly higher value of kappa (Kruskal-Wallis test p = 0.0017; Mann-Whitney test with Bonferroni’s correction p < 0.001) and lambda (Kruskal-Wallis test p = 0.0346; Mann-Whitney test with Bonferroni’s correction p = 0.013) light chains in patients with atrophic-erosive OLP (Group 1) as compared with normal controls (Group 3). However these higher levels were probably caused by strong prevalence of chronic liver diseases (40%), in patients with atrophic-erosive variety of OLP. No one of these patients was affected by autoimmune liver disease. No differences were noted between atrophic-erosive OLP (Group 1) and hyperkeratosic OLP (Group 2). This study does not confirm the suggestion that patients with OLP may have a generalized immunologic disorder and it also add some evidences that the role of humoral immunity in the pathogenesis of OLP is probably secondary to the cell-mediated reaction against basal keratinocytes.Les principaux aspects de l’immunologie humorale ont été évalués dans deux groupes de malades porteur d’un lichen plan de la muqueuse buccale, 25 à formes atrophiques-érosives (Groupe 1), 28 à formes en réseaux ou en plaques blanches (Groupe 2), et chez 21 sujets sains. Au terme de cette étude les différences les plus remarquables sont les suivantes: le taux des IgG sériques est nettement plus élevé chez les sujets du Groupe 1 ce qui est presque significatif par rapport au Groupe 3 (p = 0.0577). L’analyse statistique a surtout révélé des différences significatives entre le Groupe 1 et le Groupe 3 (contrôle) en ce qui concerne les taux sériques des chaînes Kappa (Kruskal-Wallis test p = 0.0017; Mann-Whitney test corrigé par Bonferroni p < 0.001 ) et des chaînes Lambda (Kruskal-Wallis test p = 0.0346; Mann-Whitney test corrigé par Bonferroni p = 0.013). Aucune autre différence significative entre les trois groupes n’a été observee. Nous pensons que ces résultats sont probablement dus à la présence d’une hépatopathie chronique non auto-immune qui a été diagnostiquée dans 40% des cas du Groupe 1. Cette étude ne confirme donc pas la thèse selon laquelle les sujets atteints de lichen plan buccal pourraient avoir une défaillance de l’immunité humorale. Elle nous permet de penser que le rôle de cette dernière dans la pathogénèse de la maladie est probablement secondaire à la réaction cellulaire dirigée contre les kératinocytes

Parametric analysis of transcatheter aortic valve replacement in transcatheter aortic valve replacement: evaluation of coronary flow obstruction

Transcatheter aortic valve replacement (TAVR) is increasingly being considered for use in younger patients having longer life expectancy than those who were initially treated. The TAVR-in-TAVR procedure represents an appealing strategy to treat failed transcatheter heart valves (THV) likely occurring in young patients. However, the permanent displacement of first THV can potentially compromise the coronary access and ultimately inhibit the blood flow circulation. The objective of this study was to use finite-element analysis (FEA) to quantify coronary flow in a patient who underwent TAVR-in-TAVR. A parametric investigation was carried out to determine the impact of both the implantation depth and device size on coronary flow for several deployment configurations. The FEAs consisted of first delivering the SAPIEN 3 Ultra THV and then positioning the Evolut PRO device. Findings indicates that high implantation depth and device undersize of the second THV could significantly reduce coronary flow to 20% of its estimated level before TAVR. Additionally, a positive correlation was observed between coronary flow and the valve-to-coronary distance (R = 0.86 and p = 0.032 for the left coronary artery, and R = 0.93 and p = 0.014 for the right coronary artery). This study demonstrated that computational modeling can provide valuable insights to improve the pre-procedural planning of TAVR-in-TAVR

Phenotypic analysis of peripheral blood cell immunity in Italian patients with different varieties of oral lichen planus

Quantitative analysis of peripheral blood lymphocytes was carried out in 25 patients with atrophic-erosive type of oral lichen planus (OLP) (Group 1), in 28 patients with reticular-plaque like lesions of OLP (Group 2) and in 21 healthy patients (Group 3) by using flow cytometry. CD4 + subsets decreased significantly in patients with reticular-plaque like varieties when compared with healthy patients (Group 3) (One way analysis of variance p = 0.039; t-test with Bonferroni correction p< 0.05). Moreover, in patients with hyperkeratosic forms of OLP (Group 2) CD8 + cell populations were significantly higher than in controls (Group 3) (Kruskal-Wallis test p = 0.035; Mann-Whitney test with Bonferroni’s correction p< 0.0001) and consequently CD4/CD8 ratio was significantly lower in patients with reticular-plaque like lesions than in controls (Kruskal-Wallis test p = 0.01; Mann-Whitney test with Bonferroni’s correction p = 0.013). No statistical differences between patients of Group 1 (atrophic-erosive OLP) and the other two Groups (hyperkeratosic OLP and healthy controls) were detected. 40% of the patients of Group 1 were affected by chronic hepatopathies, most of which were related to hepatitis C virus (HCV), but the data were not substantially modified after adjustment for the patients with chronic liver disease HCV positive. There is no clear evidence that these results indicate the existence of a different pathogenetic mechanism between erosive-atrophic and hyperkeratosic types of OLP. On the other hand, these results and the previously reported immunohistochemical findings suggest that quantitative alterations of peripheral blood lymphocytes in hyperkeratosic varieties of OLP could represent a shift of CD4 + cells from the vascular to the oral mucosa compartment.Les lymphocytes du sang périphérique ont été évalués par cytométrie de flux dans deux groupes de malades porteurs d’un lichen plan de la muqueuse buccale: 25 à forme atrophique-érosive (Groupe 1), 28 à forme en réseaux ou en plaques blanches (Groupe 2), et chez 21 sujets sains (Groupe 3). Au terme de cette étude les différences les plus remarquables ont été les suivantes: diminution de la fraction CD4 + et une augmentation de la fraction CD8 + dans le Groupe 2 (réseaux et plaques blanches) comparés au Groupe 3 (contrôle), la différence est statistiquement significative (One ways analysis of variance p = 0.039, t test corrigé par Bonferroni p<0.05 pour CD4 + et Kruskal-Wallis test p = 0.035, Mann-Whitney test corrigé par Bonferroni p< 0.001 pour CD8 + ) par conséquent le rapport CD4/CD8 du Groupe 2 a été significativement plus bas par rapport au Groupe 3 (Kruskal-Wallis test p = 0.014; Mann-Whitney test corrigé par Bonferroni p = 0.013). Aucune autre différence significative entre les trois groupes n’a été observée, en particulier avec le Groupe 1 (formes atrophiques-érosives) dont il faut signaler que le 40% des sujets sont porteurs d’une hépatopathie chronique souvent due au virus de l’hépatite C. En conclusion la différence des résultats entre les groupes 1 et 2 ne permet pas d’affirmer l’existence d’une pathogénie différente entre les formes atrophiques-érosives et les formes en réseaux ou en plaques, elle est en accord avec les précédentes études en histo-immunochimie. Il est possible que la diminution des lymphocytes CD4 + soit secondaire au déplacement de cette population cellulaire du compartement vasculaire de la muqueuse affectée par le lichen plan.

Shift in critical temperature for random spatial permutations with cycle weights

We examine a phase transition in a model of random spatial permutations which originates in a study of the interacting Bose gas. Permutations are weighted according to point positions; the low-temperature onset of the appearance of arbitrarily long cycles is connected to the phase transition of Bose-Einstein condensates. In our simplified model, point positions are held fixed on the fully occupied cubic lattice and interactions are expressed as Ewens-type weights on cycle lengths of permutations. The critical temperature of the transition to long cycles depends on an interaction-strength parameter $\alpha$. For weak interactions, the shift in critical temperature is expected to be linear in $\alpha$ with constant of linearity $c$. Using Markov chain Monte Carlo methods and finite-size scaling, we find $c = 0.618 \pm 0.086$. This finding matches a similar analytical result of Ueltschi and Betz. We also examine the mean longest cycle length as a fraction of the number of sites in long cycles, recovering an earlier result of Shepp and Lloyd for non-spatial permutations.Comment: v2 incorporated reviewer comments. v3 removed two extraneous figures which appeared at the end of the PDF

Cluster Percolation in O(n) Spin Models

The spontaneous symmetry breaking in the Ising model can be equivalently described in terms of percolation of Wolff clusters. In O(n) spin models similar clusters can be built in a general way, and they are currently used to update these systems in Monte Carlo simulations. We show that for 3-dimensional O(2), O(3) and O(4) such clusters are indeed the physical `islands' of the systems, i.e., they percolate at the physical threshold and the percolation exponents are in the universality class of the corresponding model. For O(2) and O(3) the result is proven analytically, for O(4) we derived it by numerical simulations.Comment: 11 pages, 8 figures, 2 tables, minor modification