Staphylococcus aureus and Bacillus subtilis W23 make polyribitol wall teichoic acids using different enzymatic pathways

Wall teichoic acids (WTAs) are anionic polymers that play key roles in bacterial cell shape, cell division, envelope integrity, biofilm formation, and pathogenesis. B. subtilis W23 and S. aureus both make polyribitol-phosphate (RboP) WTAs and contain similar sets of biosynthetic genes. We use in?vitro reconstitution combined with genetics to show that the pathways for WTA biosynthesis in B. subtilis W23 and S.?aureus are different. S. aureus requires a glycerol-phosphate primase called TarF in order to make RboP-WTAs; B. subtilis W23 contains a TarF homolog, but this enzyme makes glycerol-phosphate polymers and is not involved in RboP-WTA synthesis. Instead, B. subtilis TarK functions in place of TarF to prime the WTA intermediate for chain extension by TarL. This work highlights the enzymatic diversity of the poorly characterized family of phosphotransferases involved in WTA biosynthesis in Gram-positive organisms.     

Integrated optical receiver for indoor wireless gigabit communication

A receiver with a monolithically integrated PIN photodiode in 0.5 μm BiCMOS technology has been developed for establishing an indoor 1.25 Gb/s optical wireless communication over a distance of 3.2 m using 180 μW of optical power.     

Particle image velocimetry of active flow control on a compressor cascade

AFC (Active Flow Control) experiments have been performed by means of steady and pulsed blowing out of the sidewalls as well as out of the blade’s suction surface in a highly loaded compressor cascade. PIV (Particle Image Velocimetry) was used to evaluate the fully three-dimensional internal flow field and the impact of AFC methods. The aim was to observe the secondary flow structures and flow instabilities by PIV, to tune the AFC device operation parameters. This paper summarizes the different PIV measurements performed at the stator cascade to give an overview of the dominant flow features in the passage flow field and to obtain a detailed view of control mechanisms. In addition, a new vortex detection method is presented, based on a 2D-wavelet which is applicable in two-dimensional velocity data fields.     

Probing single-photon ionization on the attosecond time scale

We study photoionization of argon atoms excited by attosecond pulses using an interferometric measurement technique. We measure the difference in time delays between electrons emitted from the 3s(2) and from the 3p(6) shell, at different excitation energies ranging from 32 to 42 eV. The determination of photoemission time delays requires taking into account the measurement process, involving the interaction with a probing infrared field. This contribution can be estimated using a universal formula and is found to account for a substantial fraction of the measured delay.     

Zum Nachweis der Pikrins?ure

Ohne Zusammenfassung     

Die Bestimmung des Cers im Edelstahl

Zusammenfassung 1. Es wird die Cerbestimmung mit verschiedenen F?llungsmitteln unter wechselnden Versuchsbedingungen ausgeführt, und zwar a) in reiner, eisenfreier Cerl?sung, b) in eisenfreier Cerl?sung, jedoch in Anwesenheit von Legierungselementen, die bei Schnelldrehst?hlen in Betracht kommen. 2. Es wird die F?llung des Cers als Fluorid in eisenhaltigen L?sungen, die mit Hilfe von Cernitrat und Schnelldrehstahlsp?nen hergestellt wurden, durchgeführt, und zwar a) ohne vorhergehende Abscheidung des Eisens, b) nach vorhergehender Abscheidung des Eisens. 3. Für die Eisen-Cer-Trennung wird zum Zwecke der Ausf?llung des Eisens in weins?urehaltiger L?sung Zinnchlorür und Natronlauge, nicht aber Kalilauge, in Vorschlag gebracht. 4. Es wird eine Methode zur Cer-Bestimmung im Stahl, insbesondere im Schnelldrehstahl, mitgeteilt.     

Die Bestimmung des Tantals, Wolframs, Vanadins und Molybd?ns im Sehnelldrehstahl

Ohne Zusammenfassung     

Zur Kenntnis cyclischer Acylale, 2. Mitt.

Ohne Zusammenfassung     

Bestimmung der Verteilung einiger Elemente in hochborhaltigen Eisen-Chrom-Nickel-Legierungen

Ohne ZusammenfassungVortrag anläßlich des Kolloquiums für metallkundliche Analyse mit besonderer Berücksichtigung der Elektronenstrahl-Mikroanalyse, Wien, 22. Oktober 1964.