Über die Untersuchungen von A. H. Blaauw,betreffend die Beziehung zwischen Lichtintensität und Beleuchtungsdauer bei der phototropischen Krümmung von Keimlingen vonAvena sativa

Ohne ZusammenfassungProceedings of the Meetings of Saturday September 26, 1908.Die vorliegende Übersetzung, zu der Herr Prof. Went mich gütigst autorisierte, rechtfertigt sich durch die in theoretischer, ganz besonders aber in methodologischer Hinsicht überaus wichtigen Ergebnisse Blaauws. Die Untersuchung bestätigt zunächst ein Gesetz, das der Übersetzer für die Abhängigkeit der Präsentationszeit von der Lichtintensität festgestellt hat (die diesbezügliche Abhandlung war Herrn Prof. Went zur Zeit, als er dieses Referat schrieb, noch nicht zu Gesicht gekommen), verfolgt aber diese Gesetzmäßigkeit innerhalb wesentlich weiterer Grenzen. Die Feststellung ganz besonders, daß bei entsprechend intensiver Beleuchtung die Präsentationszeit bis auf 1/1000 Sekunde sinkt, zusammengehalten mit den Tatsachen der feinen Unterschiedsempfind-lichkeit der Pflanzen (Wiesner) und der außerordentlich kurzen Perzeptions-zeit (Fitting), muß die reizphysiologische Methodik reformieren und sie zu ebenso exaktem Arbeiten anspornen, wie es bei psychophysischen Experimenten längst der Fall ist.     

A para-nitrophenol phosphonate probe labels distinct serine hydrolases of Arabidopsis

Activity-based protein profiling represents a powerful methodology to probe the activity state of enzymes under various physiological conditions. Here we present the development of a para-nitrophenol phosphonate activity-based probe with structural similarities to the potent agrochemical paraoxon. We demonstrate that this probes labels distinct serine hydrolases with the carboxylesterase CXE12 as the predominant target in Arabidopsis thaliana. The designed probe features a distinct labeling pattern and therefore represents a promising chemical tool to investigate physiological roles of selected serine hydrolases such as CXE12 in plant biology.     

Characterization of sequential immune complexes in infective endocarditis by Western blot analysis

A patient with cutaneous vasculitis during infective endocarditis due to Lactobacillus casei was studied. Immune complexes (IC) were isolated from serum at the time of diagnosis and after 4 wk of therapy. Purification of IC used differential polyethylene glycol precipitation and competitive binding to staphylococcal protein A. In situ radioiodination of IC was performed, followed by SDS-polyacrylamide gel electrophoresis (PAGE). Anti-IC antisera were raised in rabbits by immunization with purified IC. IC were characterized by SDS-PAGE followed by electrophoretic transfer to nitrocellulose, incubation with antiserum and then with 125I protein A, and autoradiography. Although early and late IC differed quantitatively, there were no differentiating immunochemical features. Both IC contained a 60,000 dalton component that did not react with preimmune serum nor with anti-normal human serum. This component reacted with antiserum rendered specific for L. casei by affinity chromatography. The restricted antigen-antibody representation in IC contrasted with a wider panel of antibody activity in patient serum. The Western blot analysis proves to be an ideal method for the characterization of IC because of its sensitivity, dissociative capability, and preservation of immunoreactivity. IC isolated at a time removed from the original antigenic challenge may provide insight into the nature of the inciting antigen.