Quantum dissipative dynamics of a bistable system in the sub-Ohmic to super-Ohmic regime

We investigate the quantum dynamics of a multilevel bistable system coupled to a bosonic heat bath beyond the perturbative regime. We consider different spectral densities of the bath, in the transition from sub-Ohmic to super-Ohmic dissipation, and different cutoff frequencies. The study is carried out by using the real-time path integral approach of the Feynman-Vernon influence functional. We find that, in the crossover dynamical regime characterized by damped \emph{intrawell} oscillations and incoherent tunneling, the short time behavior and the time scales of the relaxation starting from a nonequilibrium initial condition depend nontrivially on the spectral properties of the heat bath.Comment: 16 pages, 7 figure

Finite-temperature geometric properties of the Kitaev honeycomb model

We study finite-temperature topological properties of the Kitaev’s spin-honeycomb model in the vortex-free sector with the use of the recently introduced mean Uhlmann curvature. We employ an appropriate fermionization procedure to study the system as a two-band p-wave superconductor described by a Bogoliubov–de Gennes Hamiltonian. This allows us to study relevant quantities such as Berry and mean Uhlmann curvatures in a simple setting. More specifically, we consider the spin honeycomb in the presence of an external magnetic field breaking time-reversal symmetry. The introduction of such an external perturbation opens up a gap in the phase of the system characterized by non-Abelian statistics. The resulting model belongs to a symmetry-protected class, so that the Uhlmann number can be analyzed. We first consider the Berry curvature on a particular evolution line over the phase diagram. The mean Uhlmann curvature and the Uhlmann number are then analyzed by assuming a thermal state. The mean Uhlmann curvature describes a crossover effect as temperature rises. In the trivial phase, a nonmonotonic dependence of the Uhlmann number, as temperature increases, is reported and explained

Cell Propagation of Cholera Toxin CTA ADP-Ribosylating Factor by Exosome Mediated Transfer

In this study, we report how the cholera toxin (CT) A subunit (CTA), the enzyme moiety responsible for signaling alteration in host cells, enters the exosomal pathway, secretes extracellularly, transmits itself to a cell population. The first evidence for long-term transmission of CT's toxic effect via extracellular vesicles was obtained in Chinese hamster ovary (CHO) cells. To follow the CT intracellular route towards exosome secretion, we used a novel strategy for generating metabolically-labeled fluorescent exosomes that can be counted by flow cytometry assay (FACS) and characterized. Our results clearly show the association of CT with exosomes, together with the heat shock protein 90 (HSP90) and Protein Disulfide Isomerase (PDI) molecules, proteins required for translocation of CTA across the ER membrane into the cytoplasm. Confocal microscopy showed direct internalization of CT containing fluorescent exo into CHO cells coupled with morphological changes in the recipient cells that are characteristic of CT action. Moreover, Me665 cells treated with CT-containing exosomes showed an increase in Adenosine 3',5'-Cyclic Monophosphate (cAMP) level, reaching levels comparable to those seen in cells exposed directly to CT. Our results prompt the idea that CT can exploit an exosome-mediated cell communication pathway to extend its pathophysiological action beyond an initial host cell, into a multitude of cells. This finding could have implications for cholera disease pathogenesis and epidemiology

Discourses of Professionalism in Front-Line Service Work: Insights from a Case Study in an Italian Bank

The article draws on the literature on the triangular employment relationship in the service industry, as well as on the debate on contemporary forms of professionalism, to explore the varied uses of the discourse of professionalism in a banking company. Methodologically, it is a single-case study based on 61 semi-structured interviews, company documents and observational data. The research results show how, in the company studied, the notion of professionalism was used both by individual employees and, at the collective level, by union organizations to advance front-line employees' and customers' interests vis-a-vis the management. Moreover, rather than a single discourse, several discourses of professionalism coexisted within the company, and they were subject to constant debate and contestation. The article thus advances extant research on both contemporary forms of service work and professionalism, while providing a bridge between these two streams of literature which, to date, have barely talked to each other

A paradox view on green human resource management: Insights from the Italian context

Paradox - understood as a set of contradictory and incompatible poles all supported by apparently sound arguments - is considered to be a key element in modern organizations. As a result, paradox scholars argue that successful managers are those able to accept the tensions arising fromthe paradox and able to pursue all its constitutive poles simultaneously instead of choosing only one of them. Paradox theory has been recently applied to corporate sustainability, and it is a theoretical approach that has been endorsed by influential authors also in the human resource management (HRM) field. In this context, this paper takes the still unexplored opportunity to apply paradox theory to green HRM. In particular, it explores the HRM-related paradoxes perceived by organizations developing environmental sustainability via HRM. Adopting a comparative multiple case study approach, semi-structured interviews and document analysis were conducted in six Italian companies explicitly pursuing an environmental strategy. The findings encompass the main characteristics of the green HRM systems of the organizations analyzed, and a list is provided of eight HRM-related paradoxes perceived by those organizations. For each paradox, we present and discuss its contrasting poles and the components of the HRM system that it affects. The implications of the findings for both green HRM research and practice are presented and discussed

‘Activists in a Suit’: Paradoxes and Metaphors in Sustainability Managers’ Identity Work

Both sustainability and identity are said to be paradoxical issues in organizations. In this study we look at the paradoxes of corporate sustainability at the individual level by studying the identity work of those managers who hold sustainability-dedicated roles in organizations. Analysing 26 interviews with sustainability managers, we identify three main tensions affecting their identity construction process: the business versus values oriented, the organizational insider versus outsider and the short-term versus long-term focused identity work tensions. When dealing with these tensions, some interviewees express a paradoxical perspective in attempting to accept and maintain the two poles of each of them simultaneously. It emerges in particular that metaphorical reasoning can be used by sustainability managers in varied ways to cope with the tensions of identity work. We read these findings in light of the existing literature on the relation between paradoxes and identity work, highlighting and discussing their implications for both research and practice

Exploring representations of human resource management as moral dirty work: A film study

It has been claimed that the HR “profession” suffers from a chronic shortage of social legitimacy. In this article, we advance the idea that HR is also to some extent subject to public stigmatization for being immoral. In other words, we maintain that certain aspects of contemporary HR work can be conceptualized as morally dirty work. We provide empirical support for this contention by analyzing a set of 28 films portraying HR practitioners at work. The research results comprise both task-related and method-related filmic representations of HR work as immoral, thus furnishing a comprehensive and nuanced picture of the moral issues that can affect the HR profession. Furthermore, the results show that some of the HR characters analyzed—typically those who hold a role as (co-)protagonists in the story—realize the immorality affecting their work and decide to distance themselves from it by either exiting the role, trying to reform it, or openly raising resistance against their employer. These research results suggest the need to integrate dirty work scholarship into study of the HR profession, while they provide important indications in terms of future HR research, practice and education