Automated UV-C mutagenesis of Kluyveromyces marxianus NRRL Y-1109 and selection for microaerophilic growth and ethanol production at elevated temperature on biomass sugars.

The yeast Kluyveromyces marxianus is a potential microbial catalyst for fuel ethanol production from a wide range of biomass substrates. To improve its growth and ethanol yield at elevated temperature under microaerophilic conditions, K. marxianus NRRL Y-1109 was irradiated with UV-C using automated protocols on a robotic platform for picking and spreading irradiated cultures and for processing the resulting plates.

Ultrathin SiO(2) layers on Si(111): preparation, interface gap states and the influence of passivation.

An essential prerequisite for the successful application of Si/SiO(2) nanostructures in photovoltaics is the realization of well-defined and abrupt interfaces with low densities of interface gap states. Here, a complete in situ process from preparation and hydrogen passivation to interface gap state analysis by near-UV photoelectron spectroscopy without breaking ultrahigh vacuum (UHV) conditions is introduced. It is demonstrated that by RF plasma oxidation of Si(111) substrates with thermalized neutral oxygen atoms, ultrathin SiO(2) layers can be realized with compositionally and structurally abrupt Si/SiO(2) interfaces and a minimal amount of intermediate oxidation states bridging the transition from Si to SiO(2).

Effectiveness of personal protection measures against mosquito bites for malaria prophylaxis in travelers.

Background: To determine the effectiveness of personal protection measures (PPM) against mosquito bites in travelers as tools of malaria prevention.

Methods: Two step questionnaire survey conducted in European tourists who visited East Africa: cross-sectional evaluation during the return flight with follow-up 12 weeks after return home. Among 100,336 tourists participating in a malaria survey, 89,617 had answered all questions relating to PPM and to malaria occurrence.