Development of a Modular Biosensor System for Rapid Pathogen Detection

Progress in the field of pathogen detection relies on at least one of the following three qualities: selectivity, speed, and cost-effectiveness. Here, we demonstrate a proof of concept for an optical biosensing system for the detection of the opportunistic human pathogen Pseudomonas aeruginosa while addressing the abovementioned traits through a modular design. The biosensor detects pathogen-specific quorum sensing molecules and generates a fluorescence signal via an intracellular amplifier. Using a tailored measurement device built from low-cost components, the image analysis software detected the presence of P. aeruginosa in 42 min of incubation. Due to its modular design, individual components can be optimized or modified to specifically detect a variety of different pathogens. This biosensor system represents a successful integration of synthetic biology with software and hardware engineering

Functional conservation of the Drosophila hybrid incompatibility gene Lhr

<p>Abstract</p> <p>Background</p> <p>Hybrid incompatibilities such as sterility and lethality are commonly modeled as being caused by interactions between two genes, each of which has diverged separately in one of the hybridizing lineages. The gene <it>Lethal hybrid rescue </it>(<it>Lhr</it>) encodes a rapidly evolving heterochromatin protein that causes lethality of hybrid males in crosses between <it>Drosophila melanogaster </it>females and <it>D. simulans </it>males. Previous genetic analyses showed that hybrid lethality is caused by <it>D. simulans Lhr </it>but not by <it>D. melanogaster Lhr</it>, confirming a critical prediction of asymmetry in the evolution of a hybrid incompatibility gene.</p> <p>Results</p> <p>Here we have examined the functional properties of <it>Lhr </it>orthologs from multiple Drosophila species, including interactions with other heterochromatin proteins, localization to heterochromatin, and ability to complement hybrid rescue in <it>D. melanogaster</it>/<it>D. simulans </it>hybrids. We find that these properties are conserved among most <it>Lhr </it>orthologs, including <it>Lhr </it>from <it>D. melanogaster</it>, <it>D. simulans </it>and the outgroup species <it>D. yakuba</it>.</p> <p>Conclusions</p> <p>We conclude that evolution of the hybrid lethality properties of <it>Lhr </it>between <it>D. melanogaster </it>and <it>D. simulans </it>did not involve extensive loss or gain of functions associated with protein interactions or localization to heterochromatin.</p

Coupling general circulation models on a meta-computer

Sophisticated climate models, describing the circulation in atmosphere and oceans, respectively, have been coupled together. This has been done using two different remote supercomputers in an efficient way for the first time. Two state-of-the-art climate models have been chosen, a coupling tool has been adapted, and a new developed message-passing library has been used

Welthandel mit Steinkohle Preisentwicklung fuer Kesselkohlenimporte in die Bundesrepublik Deutschland bis 2010

Im Jahr 1993 wurden im Seeverkehr 360 Mio. t Steinkohle gehandelt. Davon waren 200 Mio. t fuer Kernkraftwerke bestimmte Kesselkohle. Ihr Preis erreicht mit rund 70 DM/t Steinkohleneinheit (SKE) den niedrigsten Stand seit 20 Jahren. Eine im August 1994 veroeffentlichte Studie der Rheinbraun AG, die die Preisentwicklung fuer Kesselkohleimport nach Deutschland bis zum Jahre 2010 untersucht, wagt die Prognose, dass die Talsohle in der Preisentwicklung nunmehr erreicht ist und es in den kommenden 15 Jahren zu einem kontinuierlichen Preisanstieg kommen wird. Dieser aber werde keinesfalls bewirken, dass sich die Wettbewerbsfaehigkeit der Importkesselkohle gegenueber Oel und Gas verschlechtere. Im Gegenteil. Die vier Autoren der Studie analysieren zunaechst die Ausgangslage in den wichtigsten kohleexportierenden Staaten. Es folgen Thesen zum Transport, zur Nachfrage- und Preisentwicklung weltweit. (HS)In 1993, 360 million tons of black coal were shipped overseas. 200 million tons of this were steam coal for power plants. Their price, appr. 70 DM/t hard coal unit (SKE), is on its lowest level of 20 years. An investigation by Rheinbraun AG published in August 1994 discussed the development of the price level has now reached its minimum and there will be a continuous price rise over the next 15 years. This, however, is not expected to weaken the competitive strength of imported steam coal as compared with petroleum and gas. The four authors of the investigation first analyse the starting situation in the most important coal-exporting countries. This is followed by theses on transport, demand and price development world-wide. (HS)SIGLEAvailable from TIB Hannover / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman