Antimicrobial peptide defense in Drosophila

Drosophila responds to a septic injury by the rapid synthesis of antimicrobial peptides. These molecules are predominantly produced by the fat body, a functional equivalent of mammalian liver, and are secreted into the hemolymph where their concentrations can reach up to 100 microM. Six distinct antibacterial peptides (plus isoforms) and one antifungal peptide have been characterized in Drosophila and their genes cloned. The induction of the gene encoding the antifungal peptide relies on the sp?tzle/Toll/cactus gene cassette, which is involved in the control of dorsoventral patterning in the embryo, and shows interesting structural and functional similarities with cytokine-induced activation of NF-kappa B in mammalian cells. An additional pathway, dependent on the as yet unidentified imd (for immune-deficiency) gene, is required for the full induction of the antibacterial peptide genes. Mutants deficient for the Toll and imd pathways exhibit a severely reduced survival to fungal and bacterial infections, respectively. Recent data on the molecular mechanisms underlying recognition of non-self are also discussed in this review.     

An indicator of the risk of voltage profile instability forreal-time control applications

A newly developed indicator that can be used to determine the variation in demand that a power system can withstand is presented. Unlike most indicators that are currently available, the new indicator can be used as a forecasting tool. The results presented show that it is feasible to utilize the indicator in Electricite de France's new national control center     

Definition of encapsulation barrier requirements: A method applied to organic solar cells

To reach sufficient lifetime for commercial applications, organic solar cells (OPV) require encapsulation with a low permeability barrier material toward atmosphere oxidizing agents, specifically water. Moreover, barrier materials should have the same driving aspects as organic devices like transparency, flexibility and low cost processing techniques such as coating or lamination. The generally admitted value of 10^?6 g m^?2 day^?1 for water vapor transmission rate (WVTR) derived from OLED technology should not be considered as an applicable golden rule and some recent studies demonstrate that OPV cells can be protected with medium barrier materials with a WVTR of around 10^?3 g?m^?2 day^?1. This improved stability is mainly related to the development of new cell architectures. However, a global barrier requirement cannot be defined, but has to be on one hand established in direct relationship between intrinsic stability of the device and on the other hand on the targeted lifetime and operating conditions. In this study, we applied a method to define rapidly the barrier requirement of two OPV cell types named classical and inverted structures. This method combines barrier measurements of encapsulating materials with accelerated lifetime experiments of encapsulated cells and enables to establish the barrier levels necessary to ensure the protection of a given device depending on the intrinsic stability and targeted lifetime.     

Non-prismatic sub-stiffening for stiffened panel plates—Stability behaviour and performance gains

Previous work has demonstrated the potential to introduce plate element sub-stiffening to increase the local stability and thus static strength performance of integrally machined aluminium alloy stiffened panels. The introduction of plate element prismatic sub-stiffening modifies local plate buckling behaviour and within realistic design constraints, may produce sizable performance gains with equivalent mass designs. This article examines through experimental and computational analysis the potential of non-prismatic sub-stiffening for tailoring local plate stability performance. Using non-prismatic sub-stiffening, the experimental work demonstrates potential initial buckling performance gains with equivalent mass designs (+185%), and computationally, potential mass savings with equivalent static strength performance designs (−9.4%).     

IMGT, the international ImMunoGeneTics database

Propofol emulsion supports bacterial growth. Extrinsic contamination of propofol has been implicated as an etiological event in postsurgical infections. When added to propofol, local anesthetics (e.g., lidocaine) alleviate the pain associated with injecting it. Because local anesthetics have antimicrobial activity, we determined whether lidocaine would inhibit microbial growth by comparing the growth of four microorganisms in propofol and in mixtures of propofol and lidocaine. Known quanta of Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, and Candida albicans were inoculated into solutions of 1% propofol, 0.2% lidocaine in propofol, 0.5% lidocaine in propofol, 0.5% lidocaine in isotonic sodium chloride solution, and 0.9% isotonic sodium chloride solution. All microorganisms were taken from stock cultures and incubated for 24 h. Growth of microorganisms in each solution was compared by counting the number of colony-forming units grown from a subculture of the solution at 0, 3, 6, 12 and 24 h. Propofol supported the growth of E. coli and C. albicans. Propofol maintained static levels of S. aureus and was bactericidal toward P. aeruginosa. The addition of 0.2% and 0.5% lidocaine to propofol failed to prevent the growth of the studied microorganisms. The effect of 0.5% lidocaine in isotonic sodium chloride solution did not differ from the effects of isotonic sodium chloride solution alone. We conclude that lidocaine, when added to propofol in clinically acceptable concentrations, does not exhibit antimicrobial properties. IMPLICATIONS: Local anesthetics such as lidocaine have antimicrobial activity. Propofol supports the growth of bacteria responsible for infection. Bacteria were added to propofol and propofol mixed with lidocaine. The addition of lidocaine to propofol in clinically relevant concentrations did not prevent the growth of bacteria. The addition of lidocaine to propofol cannot prevent infection from contaminated propofol.     

Mixed digital/analog signal processing for a single-chip 2B1Q U-interface transceiver

Mixed analog-digital signal processing aspects of a 5-V single-chip U-interface 2B1Q transceiver are discussed. Analog signal processing preconditions the signal by reducing jitter-induced echo and nonlinear echo components, and by maximizing the dynamic range utilization of the 13-b analog-to-digital (A/D) converter. The digital signal processor performs the high-pass filtering, precursor equalization, linear echo cancellation, far-end signal equalization, and timing recovery functions. The analog signal preconditioning technique allows the entire digital signal processing (DSP) section to be designed without a single dedicated multiplier. The U-interface transceiver has been realized in a 1.5-μm double-metal CMOS process, resulting in a circuit area of 77 mm². Total power consumption is 300 mW. To comply with the ANSI-specified performance test procedures, a crosstalk noise generator and injection circuit were custom built along with a jitter generation system, all of which match the ANSI noise and jitter templates. Testing was performed over the 15 ANSI loops and countless other random configurations. Full compliance with the standard protocol and timing limits was achieved on all the loops     

Ferromagnetism in Ga0.90Mn0.10As1 − yPy: From the metallic to the impurity band conduction regime

The magnetic properties of low temperature MBE grown Ga_0.90Mn_0.10As_1 − yP_y films with 0 < y < 0.20 have been studied as a function of the phosphorous content. The films are ferromagnetic for all phosphorous compositions. For y < 0.15 the conductivity type is metallic but above y > 0.15 it changes to impurity band conduction (IBC). In the IBC regime the main magnetic properties are profoundly modified: the saturation magnetization decreases from typically 50 emu/cm³ to 35 emu/cm³, the critical temperature drops sharply from 130 K to 45 K and the uniaxial magnetic anisotropy spectroscopy is strongly reduced.     

The estimation of the charge transfer resistance by graphical analysis of inclined semicircular complex impedance diagrams

Recently a graphical method for the determination of the charge transfer resistance, obtained from impedance measurements, was developed. The original method was limited to perfect, semicircular Nyquist plots. Extension to inclined or depressed semicircular arcs is made possible by a few simple mathematical and graphical manipulations.