Pseudo-gauges and relativistic spin hydrodynamics for interacting Dirac and Proca fields

We present the explicit expressions of different pseudo-gauge transformations for Dirac and Proca fields considering a general interaction term. The particular case of the interaction of Dirac and Proca fields with a background electromagnetic field is also studied. Starting from the quantum kinetic theory with collisions derived from the Wigner-function formalism for massive spin-1/2 and spin-1 particles, we establish a connection between different pseudo-gauges and relativistic spin hydrodynamics. The physical implications of the various decompositions of orbital and spin angular momentum are discussed.Comment: 21 pages, no figure

Quantum kinetic theory with interactions for massive vector bosons

We present a derivation of quantum kinetic theory for massive spin-1 particles from the Wigner-function formalism up to first order in an $\hbar$-expansion, including a general interaction term. Both local and nonlocal contributions are computed in a covariant fashion. It is shown that, up to first order in $\hbar$, the collision term takes the same form as in the case of spin-1/2 particles.Comment: 22 pages, no figure

Putting a Price Tag on Personal Information - A Literature Review

In the digital age, personal information is claimed to be the new commodity with a rising market demand and profitability for businesses. Simultaneously, people are becoming aware of the value of their personal information while being concerned about their privacy. This increases the demand of direct compensation or protection. In response to the commodification of privacy and the increased demand for compensation, a number of scholars have shed light on the value people assign to their personal information. However, these findings remain controversial as their results differ tremendously due to different research methods and contexts. To address this gap, we conducted a systematic literature review to gain insights into the current research state and to identify further research avenues. By synthesizing and analyzing 37 publications, we provide an integrative framework along with seven contextual factors affecting individuals’ valuation of privacy

Relativistic dissipative spin hydrodynamics from kinetic theory with a nonlocal collision term

We derive relativistic dissipative spin hydrodynamics from kinetic theory featuring a nonlocal collision term using the method of moments. In this framework, the components of the spin tensor are dynamical variables which obey relaxation-type equations. We find that the corresponding relaxation times are determined by the local part of the collision term, while the nonlocal part contributes to the Navier-Stokes terms in these equations of motion. The spin relaxation time scales are comparable to those of the usual dissipative currents. Finally, the Navier-Stokes limit of the Pauli-Lubanski vector receives contributions proportional to the shear tensor of the fluid, which implies that the polarization of hadrons observed in heavy-ion collisions is influenced by dissipative effects.Comment: 7 pages, 1 figur

What is Your Selfie Worth? A Field Study on Individuals’ Valuation of Personal Data

Referred to as the new oil, undoubtedly personal data is a valuable resource for organizations. Contrary, it is still blurred, to what extent individuals value their data even though, in a digitized world, users are requested to exchange their data for adequate services. Former research on individuals’ valuation of personal data result in scattered, partly contradictious values, depending on the data type, context, and the measurement method. In this study, we aimed to facilitate the valuation for individuals by applying a new and promising measurement methodology: the participants of our field experiment had the chance to sell their selfies in a name-your-own-price auction with repeated bidding and feedback loops. As a result, 39% of our participants were willing to donate or sell their selfies with a median of 5€. Additionally, bidding clusters were identified. Implications for research on the valuation of personal data in terms of privacy are discussed

Mutations in the Lipopolysaccharide Biosynthesis Pathway Interfere with Crescentin-Mediated Cell Curvature in Caulobacter crescentus

Bacterial cell morphogenesis requires coordination among multiple cellular systems, including the bacterial cytoskeleton and the cell wall. In the vibrioid bacterium Caulobacter crescentus, the intermediate filament-like protein crescentin forms a cell envelope-associated cytoskeletal structure that controls cell wall growth to generate cell curvature. We undertook a genetic screen to find other cellular components important for cell curvature. Here we report that deletion of a gene (wbqL) involved in the lipopolysaccharide (LPS) biosynthesis pathway abolishes cell curvature. Loss of WbqL function leads to the accumulation of an aberrant Opolysaccharide species and to the release of the S layer in the culture medium. Epistasis and microscopy experiments show that neither S-layer nor O-polysaccharide production is required for curved cell morphology per se but that production of the altered O-polysaccharide species abolishes cell curvature by apparently interfering with the ability of the crescentin structure to associate with the cell envelope. Our data suggest that perturbations in a cellular pathway that is itself fully dispensable for cell curvature can cause a disruption of cell morphogenesis, highlighting the delicate harmony among unrelated cellular systems. Using the wbqL mutant, we also show that the normal assembly and growth properties of the crescentin structure are independent of its association with the cell envelope. However, this envelope association is important for facilitating the local disruption of the stable crescentin structure at the division site during cytokinesis

Discovery of Extended Tidal Tails around the Globular Cluster Palomar 13

We use photometry from the DECam Legacy Survey to detect candidate tidal tails extending ~5 deg on either side of the Palomar 13 globular cluster. The tails are aligned with the proper motion of Palomar 13 and are consistent with its old, metal-poor stellar population. We identify three RR Lyrae stars that are plausibly associated with the tails, in addition to four previously known in the cluster. From these RR Lyrae stars, we find that the mean distance to the cluster and tails is $23.6 \pm 0.2$ kpc and estimate the total (initial) luminosity of the cluster to be $L_V=5.1^{+9.7}_{-3.4}\times 10^3 L_\odot$, consistent with previous claims that its initial luminosity was higher than its current luminosity. Combined with previously-determined proper motion and radial velocity measurements of the cluster, we find that Palomar 13 is on a highly eccentric orbit ($e\sim 0.8$) with a pericenter of ~9 kpc and an apocenter of ~69 kpc, and a recent pericentric passage of the cluster ~75 Myr ago. We note a prominent linear structure in the interstellar dust map that runs parallel to the candidate tidal features, but conclude that reddening due to dust is unlikely to account for the structure that we observe. If confirmed, the Palomar 13 stellar stream would be one of very few streams with a known progenitor system, making it uniquely powerful for studying the disruption of globular clusters, the formation of the stellar halo, and the distribution of matter within our Galaxy.Comment: 8 pages, 4 figures, 1 table. Submitted to AAS journal

Konzeptualisierung und Vergleich der Autonomie internationaler Verwaltungen

Wird eine verwaltungswissenschaftliche Perspektive für die Analyse von internationalen Organisationen fruchtbar gemacht, kann als Ausgangspunkt die Annahme dienen, dass die Leistungsfähigkeit internationaler Organisationen mit der Qualität ihrer internen Organisationsstrukturen sowie personellen und sachlichen Ressourcen zusammenhängt. Bisher gibt es aber kaum verwaltungswissenschaftliche Studien, die sich systematisch-vergleichend mit internationalen Organisationen und ihren Verwaltungsstäben auseinandersetzen. Dabei gilt, dass je mehr internationale Organisationen mit Policy-Gestaltungsaufgaben betraut werden, sich desto drängender Fragen nach deren politisch-administrativer Führung, demokratischer Legitimation und nach der Verselbständigung ihrer Verwaltungsstäbe stellen. Hier setzt der vorliegende Beitrag an. Es wird ausgelotet, ob und mit welchem analytischen Gewinn das klassische Konzept der Verwaltungsautonomie auf die Verwaltungsstäbe internationaler Organisationen übertragen werden kann. In einem ersten Schritt werden dazu die theoretischen Grundlagen der Autonomie von Verwaltungen diskutiert und, darauf aufbauend, ein Vorschlag entwickelt, wie die Autonomie internationaler Verwaltungsstäbe angemessen konzeptualisiert werden kann. In einem zweiten Schritt wird dann die Verwaltungsautonomie für 20 internationalen Organisationen operationalisiert und präsentiert, sowie anhand der Autonomiewerte zweier Verwaltungen illustriert, inwieweit die Ergebnisse geeignet sind, um Aussagen über die konkreten administrativen Gestaltungsmöglichkeiten internationaler Verwaltungen zu machen.When analyzing international organizations from a Public Administration perspective, the basic assumption is that organizational capacities are closely linked to the quality of their internal structure, as well as personnel and material resources. So far, however, only a limited number of studies have focused on international organizations and their secretariats from a Public Administration perspective. The more international organizations are entrusted with policy-making tasks, the more questions arise about their political-administrative leadership, their democratic legitimation, and the autonomy of their administrations. This article contributes to the current debate by proposing how the classic concept of bureaucratic autonomy can be applied to the secretariats of international organizations. First, we give an overview of the major theoretical approaches to organizational autonomy in order to conceptualize international bureaucratic autonomy and its components. In a second step, we develop an indicator-based measurement strategy in order to empirically capture bureaucratic autonomy. On the basis of data collected for 20 international organizations, we present descriptive empirical results and illustrate the usefulness of our approach for informing expectations about bureaucratic behavior in concrete policy-making situations