Specifying and Placing Chains of Virtual Network Functions

Network appliances perform different functions on network flows and constitute an important part of an operator's network. Normally, a set of chained network functions process network flows. Following the trend of virtualization of networks, virtualization of the network functions has also become a topic of interest. We define a model for formalizing the chaining of network functions using a context-free language. We process deployment requests and construct virtual network function graphs that can be mapped to the network. We describe the mapping as a Mixed Integer Quadratically Constrained Program (MIQCP) for finding the placement of the network functions and chaining them together considering the limited network resources and requirements of the functions. We have performed a Pareto set analysis to investigate the possible trade-offs between different optimization objectives

Ah! Could I Teach the Nightingale

Ah! could I teach the Nightingale,Three little words to number,Then should its sweet voice from the valeBreak on thy morning slumber,Then should its sweet voice from the vale,Break on the morning slumber;Ere morning\u27s dawn there should she be,Before thy window greeting,In softest tones repeating:I love thee, I love thee well,Forget, forget me not,I love thee, I love thee well,Oh! then forget me not. How oft I\u27ve sought the Nightingale,By spring and shady bower,That to my soul her plaintive tale,Might speak with music\u27s power,That to my soul her plaintive tale,Might speak with music\u27s power,Yet oh! believe me ne\u27er could be,So welcome her sweet greeting,In softest tones repeating,I love thee, I love thee well,Forget, forget me not,I love thee, I love thee well,Oh! the forget me not

Sensitive superoxide detection in vascular cells by the new chemiluminescence dye L-012

The detection superoxide production in vascular cells is usually limited by a low sensitivity of available assays, We tested the applicability of the luminol derivate L-012 {[}8-amino-5-chloro-7-phenylpyridol{[}3,4-d]pyridazine-l,4(2H,3H)dione] to measure superoxide production in cultured endothelial cells (human umbilical vein endothelial cells) and rat aortic segments. Following stimulation with the protein kinase stimulator phorbol 12-myristate 13-acetate (PMA, 1 mu M) there was an 2,8-fold increase of L-012 chemiluminescence, whereas incubation with angiotensin II (100 nM) did not result in a measurable increase. Addition of vanadate (100 mu M) considerably increased the chemiluminescence (up to 17-fold) after PMA and made possible the detection of an enhanced superoxide production after stimulation with angiotensin II (by 1.7-fold). This was due to a similar to 9-fold increase in signal intensity of L-012 in the presence of vanadate, Prolonged incubation with vanadate also led to a tyrosine phosphorylation-dependent increase in superoxide formation which was predominantly produced by an NAD(P)H oxidase. Short-Term vanadate-enhanced L-012 chemiluminescence represents a highly sensitive assay making it possible to detect small changes of superoxide formation in intact vascular cells. Copyright(C) 1999 S. Karger AG. Basel

Influential Article Review- A Multifaceted and Complex Model of Dispute and Strategic Thinking Within the Intragroup

This paper examines communication and decision making. We present insights from a highly influential paper. Here are the highlights from this paper: Although intragroup conflict has both multilevel and dynamic natures, less attention has been paid to establishing a holistic model of intragroup conflict that emerges across levels and unfolds over time. To address this research gap, we extend the multilevel view of intragroup conflict (Korsgaard et al. 2008) to develop a multilevel and dynamic model of intragroup conflict that explicitly includes (1) the role of time and (2) the feedback loop to encompass the dynamic aspect of intragroup conflict. We further instantiate the extended model in the context of team decision-making. To achieve this and systematically examine the complex relationships, we use agent-based modeling and simulation (ABMS). We directly investigate how two types of intragroup conflict—task and relationship conflict—interplay with cross-level antecedences, interrelate and develop over time, and affect team outcomes. This study adds to the intragroup conflict research by extending the field with multilevel and dynamic views. For our overseas readers, we then present the insights from this paper in Spanish, French, Portuguese, and German

Crucial role of local peroxynitrite formation in neutrophil-induced endothelial cell activation

Introduction and methods: The reaction of superoxide anions and NO not only results in a decreased availability of NO, but also leads to the formation of peroxynitrite, the role of which in the cardiovascular system is still discussed controversially. In cultured human endothelial cells, we studied whether there is a significant interaction between endothelial NO and neutrophil-derived superoxide anions in terms of endothelial peroxynitrite formation. We particularly studied whether a significantly higher redox-stress can be found in those endothelial cells directly adjacent to an activated neutrophil. Results: A considerable part of the 2,7-dihydrodichlorofluoresceine signal in endothelial cells was due to oxidation by peroxynitrite. Providing superoxide radicals by enzymatic source or by the neutrophil respiratory burst increased the fluorescence, which was attenuated by blockade of endothelial NO-synthase, suggesting that peroxynitrite was formed from neutrophil- or extracellular enzyme-derived superoxide and endothelial NO. Considerably higher fluorescence intensity was observed in endothelial cells in direct neighborhood to a neutrophil. This was particularly pronounced in the presence of a NO-donor and was accompanied by a strong activation of NF-κB and increased expression of E-selectin in these cells. Conclusion: Endothelial cells adjacent to neutrophils may have elevated levels of peroxynitrite that result in an increased expression of adhesion molecules. Such cells might represent a preferential site for adhesion and migration of additional neutrophils when simultaneously high concentrations of NO and neutrophil-derived superoxide are present

In Situ RheoNMR Correlation of Polymer Segmental Mobility with Mechanical Properties during Hydrogel Synthesis

Understanding polymer gelation over multiple length-scales is crucial to develop advanced materials. An experimental setup is developed that combines rheological measurements with simultaneous time-domain $^{1}$H NMR relaxometry (TD-NMR) techniques, which are used to study molecular motion (<10 nm) in soft matter. This so-called low-field RheoNMR setup is used to study the impact of varying degrees of crosslinking (DC) on the gelation kinetics of acrylic acid (AAc) and N,N′-methylene bisacrylamide (MBA) free radical crosslinking copolymerization. A stretched exponential function describes the T$_{2}$ relaxation curves throughout the gelation process. The stretching exponent β decreases from 0.90 to 0.67 as a function of increasing DC, suggesting an increase in network heterogeneity with a broad T$_{2}$ distribution at higher DC. The inverse correlation of the elastic modulus G′ with T2 relaxation times reveals a pronounced molecular rigidity for higher DC at early gelation times, indicating the formation of inelastic, rigid domains such as crosslinking clusters. The authors further correlate G′ with the polymer concentration during gelation using a T$_{1}$ filter for solvent suppression. A characteristic scaling exponent of 2.3 is found, which is in agreement with theoretical predictions of G′ based on the confining tube model in semi-dilute entangled polymer solutions