(2,3,7,8,12,13,17,18-Octa­ethyl-5-phenyl­porphyrinato)platinum(II)

The title compound, [Pt(C42H48N4)], was obtained through metallation of the corresponding free base with PtCl2, followed by crystallization from methyl­ene chloride/methanol. The mol­ecule exhibits an almost planar macrocycle with an average deviation of the 24 macrocyclic atoms from their least-squares plane (Δ24) of 0.04 Å and an average Pt—N bond length of 2.022 Å. Despite the unsymmetrical substitution pattern, there is no significant difference between distortion of the geometry at the phenyl substituted meso position and those of unsubstituted meso positions

Two Sides of the Same Coin? - The Effects of Hierarchy Inside and Outside Enterprise Social Networks

With more companies using Enterprise Social Networks (ESN) for employee communication and collaboration, the influence of ESN on organizational hierarchies has been subject of discussions in science and practice. Conversely, the question if formal hierarchies affect interaction inside ESN and outside (i.e., personal interaction or interaction via traditional media) in the same way has not yet been addressed. The aim of our research is to analyse those hierarchical effects. By contrasting a rich dataset comprising two years of communication and collaboration inside an ESN with data from an online survey, we found significant differences between the hierarchical effects inside and outside the ESN and their impact on communication and collaboration. Although our findings indicate significant impact of formal hierarchy, we found it to be weaker inside the ESN. We conclude that interaction inside ESN is more inclusive and balanced across hierarchical levels

WHO IS KEY...? - CHARACTERIZING VALUE ADDING USERS IN ENTERPRISE SOCIAL NETWORKS

Whereas the use of Enterprise Social Networks (ESN) is a pervasive topic in research and practice, both parties are still struggling to come to a better understanding of the role and impact of ESN in and on knowledge-intensive corporate work. As a part of this phenomenon, employees who communicate their knowledge in ESN helping other users to do their daily work play a decisive role. We need to come to a better understanding of the role and behaviour of such valu adding users. This is a prerequisite, for example, for understanding knowledge support hubs or for enabling more effective internal information and knowledge sharing. Against this background, we investigate the structural characteristics of valu adding users in ESN using qualitative text analysis and Social Network Analysis. Based on a large scale dataset of a global consulting company using the ESN Yammer.com we analyse the social relationships of valu adding users. We confirm their significant position and draw conclusions for research and practice

“Thanks for sharing”—Identifying users’ roles based on knowledge contribution in Enterprise Social Networks

While ever more companies use Enterprise Social Networks for knowledge management, there is still a lack of understanding of users' knowledge exchanging behavior. In this context, it is important to be able to identify and characterize users who contribute and communicate their knowledge in the network and help others to get their work done. In this paper, we propose a new methodological approach consisting of three steps, namely "message classification", "identification of users' roles" as well as "characterization of users' roles". We apply the approach to a dataset from a multinational consulting company, which allows us to identify three user roles based on their knowledge contribution in messages: givers, takers, and matchers. Going beyond this categorization, our data shows that whereas the majority of messages aims to share knowledge, matchers, that means people that give and take, are a central element of the network. In conclusion, the development and application of a new methodological approach allows us to contribute to a more refined understanding of users' knowledge exchanging behavior in Enterprise Social Networks which can ultimately help companies to take measures to improve their knowledge management. (C) 2018 Elsevier B.V. All rights reserved

A dynamical transition from localized to uniform scrambling in locally hyperbolic systems

Fast scrambling of quantum correlations, reflected by the exponential growth of Out-of-Time-Order Correlators (OTOCs) on short pre-Ehrenfest time scales, is commonly considered as a major signature of quantum chaos in quantum systems with a classical limit. In two recent works, by Hummel et al. [1] and by Scaffidi et al. [2], a significant difference in the scrambling rate of integrable (many-body) systems was observed, depending on the initial state being semiclassically localized around unstable fixed points or fully delocalized (infinite temperature). Specifically, the quantum Lyapunov exponent $\lambda_{\rm q}$ quantifying the OTOC growth is given, respectively, by $\lambda_{\rm q}=2\lambda_{\rm s}$ or $\lambda_{\rm q}=\lambda_{\rm w}$ in terms of the stability exponent $\lambda_{\rm s}$ of the hyperbolic fixed point. Here we show that a wave packet, initially localized around this fixed point, features a distinct {\it dynamical} transition between these two regions. We present an analytical semiclassical approach providing a physical picture of this phenomenon and support our findings by extensive numerical simulations in the whole parameter range of locally unstable dynamics of a Bose-Hubbard dimer. Our results suggest that the existence of this transition is a hallmark of unstable separatrix dynamics in integrable systems. This allows one to distinguish, within the exponential OTOC growth behavior, unstable integrable (many-body) dynamics from genuine chaotic dynamics featuring uniform growth.Comment: 11 pages, 7 figure

The Impact of Formal Hierarchies on Enterprise Social Networking Behavior

With more and more companies using enterprise social networks (ESN) for employee communication and collaboration, the influence of ESN on organizational hierarchies has been subject of countless discussions in practice-oriented media and first academic studies. Conversely, the question whether and how formal organizational hierarchies influence ESN usage behavior has not yet been addressed. Drawing on a rich data set comprising 2.5 years of relationship building via direct messages, confirmed contact requests, and group messages, we are able to show that formal hierarchies have an important impact on social networking behavior. By applying means of social network analysis and supported by statements from interviews, we illustrate how deeply formal hierarchy impacts the three examined types of relationships. Our results motivate academics to further study the interrelation between hierarchy und ESN and hierarchy’s effects regarding the sociotechnical design and implementation of related systems

THE RELATIONSHIP OF IS AND LAW - INSIGHTS INTO THE GERMAN ONLINE CAR REGISTRATION CASE

The mutual influence of Information Systems (IS) and law can be observed in projects of various industry sectors, but it seems to be prevalent in e-Government projects. Existing IS research in the field of e-Government suggests that the relationship between these two worlds has high potential for conflict and can be crucial for a project?s success. But an in-depth analysis of this specific relationship is still missing. We observed the German e-Government project ?online car registration? with a case study research approach. During the case analysis we developed a framework for the description and classification of the relationship of IS and law. The frameworks dimensions are the perceived influence direction (IS -\u3e Law, Law -\u3e IS, IS \u3c--\u3e Law), the perceived influence character (Positive, Negative, Ambivalent) and the perceived influence impact (Restrictive, Demanding, Enabling). We use this framework to structure the case and to derive project management recommendations on how to manage the relationship of IS and law in e-Government projects. The framework can further be used as a basis for a more in-depth systematic literature analysis or empirical case analyses

L-arginine: A unique amino acid for improving depressed wound immune function following hemorrhage

Objective: To determine whether L-arginine has any salutary effects on wound immune cell function following trauma-hemorrhage. Background. Depressed wound immune function contributes to an increased incidence of wound infections following hemorrhage. Although administration of L-arginine has been shown to restore depressed cell-mediated immune responses following hemorrhage potentially by maintaining organ blood flow, it remains unknown whether Larginine has any salutary effects on the depressed local immune response at the wound site. Methods: Male mice were subjected to a midline laparotomy and polyvinyl sponges were implanted subcutaneously in the abdominal wound prior to hemorrhage (35 +/- 5 mm Hg for 90 min and resuscitation) or sham operation. During resuscitation mice received 300 mg/kg body weight L-arginine or saline (vehicle). Sponges were harvested 24 h thereafter, wound fluid collected and wound immune cells cultured for 24 h in the presence of LPS. Pro- (IL-1beta, IL-6) and anti-inflammatory (IL-10) cytokines were determined in the supernatants and the wound fluid. In addition, wounds were stained for IL-6 immunohistochemically. In a separate set of animals, skin and muscle blood flow was determined by microspheres. Results: The capacity of wound immune cells to release IL-1beta and IL-6 in vitro was significantly depressed in hemorrhaged mice receiving vehicle. Administration of L-arginine, however, improved wound immune cell function. In contrast, in vivo the increased IL-6 release at the wound site was decreased in L-arginine-treated mice following hemorrhage. Moreover, IL-10 levels were significantly increased in the wound fluid in hemorrhaged animals receiving L-arginine compared to vehicle-treated mice. In addition, the depressed skin and muscle blood flow after hemorrhage was restored by L-arginine. Conclusions: Thus, L-arginine might improve local wound cell function by decreasing the inflammatory response at the wound site. Since L-arginine protected wound immune cell function this amino acid might represent a novel and useful adjunct to fluid resuscitation for decreasing wound complications following hemorrhage. Copyright beta 2002 S. Karger AG, Basel

Towards a quantum time mirror for non-relativistic wave packets

We propose a method – a quantum time mirror (QTM) – for simulating a partial time-reversal of the free-space motion of a nonrelativistic quantum wave packet. The method is based on a short-time spatially-homogeneous perturbation to the wave packet dynamics, achieved by adding a nonlinear time-dependent term to the underlying Schroedinger equation. Numerical calculations, supporting our analytical considerations, demonstrate the effectiveness of the proposed QTM for generating a time-reversed echo image of initially localized matter-wave packets in one and two spatial dimensions. We also discuss possible experimental realizations of the proposed QTM