Staphylococcus aureus proteins Sbi and Efb recruit human plasmin to degrade complement C3 and C3b

Upon host infection, the human pathogenic microbe Staphylococcus aureus (S. aureus) immediately faces innate immune reactions such as the activated complement system. Here, a novel innate immune evasion strategy of S. aureus is described. The staphylococcal proteins surface immunoglobulin-binding protein (Sbi) and extracellular fibrinogen-binding protein (Efb) bind C3/C3b simultaneously with plasminogen. Bound plasminogen is converted by bacterial activator staphylokinase or by host-specific urokinase-type plasminogen activator to plasmin, which in turn leads to degradation of complement C3 and C3b. Efb and to a lesser extend Sbi enhance plasmin cleavage of C3/C3b, an effect which is explained by a conformational change in C3/C3b induced by Sbi and Efb. Furthermore, bound plasmin also degrades C3a, which exerts anaphylatoxic and antimicrobial activities. Thus, S. aureus Sbi and Efb comprise platforms to recruit plasmin(ogen) together with C3 and its activation product C3b for efficient degradation of these complement components in the local microbial environment and to protect S. aureus from host innate immune reactions

On the Imbalance of Distributions of Solutions of CNF-Formulas and its Impact on Satisfiability Solvers

Let F be Boolean formulas in conjunctive normal form with n variables, r clauses, every clause has length s. We show that if F is split into two subformulas F_{v} and F_{overline{v}} by setting v true and false in F, then the expected number of solutions of one of the two subformulas F_{v} and F_{overline{v}} is significantly higher than that in the other subformula, when dealing with classes of formulas where the great majority of formulas is satisfiable. We discuss practical consequences of this result

Context-Dependent Information Elements in the Car: Explorative Analysis of Static and Dynamic Head-Up-Displays

Head-up-displays (HUDs) illustrate a particular static number of information elements in the driver’s primary field of view. Since the display can obscure the reality, a dynamic HUD presents context-dependent information elements. To become familiar with a user-optimal number of information elements and its essential information elements, we conducted a user study with n = 183 participants. We focused the context on an urban, a rural and a highway trip. Afterwards, a within-subject experiment using a high-fidelity driving simulator (n = 27) reveals the following: Dynamic HUDs significantly lower the average over speeding by 3.45 km/h compared to static HUDs. This speed above the speed limit equals 15.33% of the average speed in urban areas. Steering angle and speed can capture the context. Practitioners can use these findings to decrease the number of information elements in HUDs, thereby possibly increasing traffic safety

Two-photon interference from remote deterministic quantum dot microlenses

This article may be downloaded for personal use only. Any other use requires prior permission of the author and AIP Publishing. This article appeared in Appl. Phys. Lett. 110, 011104 (2017) and may be found at https://doi.org/10.1063/1.4973504.We report on two-photon interference (TPI) experiments using remote deterministic single-photon sources. Employing 3D in-situ electron-beam lithography, we fabricate quantum-light sources at specific target wavelengths by integrating pre-selected semiconductor quantum dots within monolithic microlenses. The individual single-photon sources show TPI visibilities of 49% and 22%, respectively, under pulsed p-shell excitation at 80 MHz. For the mutual TPI of the remote sources, we observe an uncorrected visibility of 29%, in quantitative agreement with the pure dephasing of the individual sources. Due to its efficient photon extraction within a broad spectral range (>20 nm), our microlens-based approach is predestinated for future entanglement swapping experiments utilizing entangled photon pairs emitted by distant biexciton-exciton radiative cascades.DFG, 43659573, SFB 787: Halbleiter - Nanophotonik: Materialien, Modelle, BauelementeEC/FP7/615613/EU/External Quantum Control of Photonic Semiconductor Nanostructures/EXQUISIT

Anbau von Raps mit Kleeuntersaat im ökologischen Landbau

Im ökologischen Landbau ist der Anbau von Raps aufgrund des Schädlingsbefalls mit einem hohen Risiko behaftet (Petterson et. al. 2002; Haas u. Kramer, 1995). Weiterhin stellt Raps als stark stickstoff- (N) -zehrende Kultur hohe Ansprüche an die Vorfrucht und an die organische Düngung (Gruber, 2001; Mayer et. al., 2001; Loges u. Böhm, 2001). Er konkurriert aus diesem Grund im ökologischen Landbau mit Weizen um den Platz in der Fruchtfolge. Für die N-Versorgung der Nachfrucht erscheint es daher günstig, im Raps eine Kleeuntersaat zu etablieren. Es wurden verschiedene Verfahren des Rapsanbaus erprobt. Eine Weisskleeuntersaat zwischen den Reihen trug im ersten Versuchsjahr weder meßbar zu einer Verbesserung der N-Versorgung von Winterraps bei, noch konnte nachgewiesen werden, dass sie durch die Kleeuntersaat verschlechtert wurde. Der Versuch zeigte, dass Kleeuntersaat in Winterraps während der Vegetationsperiode N im Bodenprofil halten kann. Lagernder Raps war bei einer Weisskleeuntersaat nur mit großen Ernteverlusten zu beernten. Jedoch blieb eine bereits gut etablierte Leguminosenvorfrucht für den Anbau von Winterweizen zurück. Der Versuch wird als Exaktversuch mit verschiedenen Reihenabständen fortgesetzt