Highly adaptable and sensitive protease assay based on fluorescence resonance energy transfer

Proteases are widely used in analytical sciences and play a central role in several widespread diseases. Thus, there is an immense need for highly adaptable and sensitive assays for the detection and monitoring of various proteolytic enzymes. We established a simple protease fluorescence resonance energy transfer (pro-FRET) assay for the determination of protease activities, which could in principle be adapted for the detection of all proteases. As proof of principle, we demonstrated the potential of our method using trypsin and enteropeptidase in complex biological mixtures. Briefly, the assay is based on the cleavage of a FRET peptide substrate, which results in a dramatic increase of the donor fluorescence. The assay was highly sensitive and fast for both proteases. The detection limits for trypsin and enteropeptidase in Escherichia coli lysate were 100 and 10 amol, respectively. The improved sensitivity for enteropeptidase was due to the application of an enzyme cascade, which leads to signal amplification. The pro-FRET assay is highly specific as even high concentrations of other proteases did not result in significant background signals. In conclusion, this sensitive and simple assay can be performed in complex biological mixtures and can be easily adapted to act as a versatile tool for the sensitive detection of proteases.     

Occurrence, distribution and fluxes of benzotriazoles along the German large river basins into the North Sea

Benzotriazole (BT) and tolyltriazole (TT) are high production volume chemicals which are used in various industrial and household applications. In this study, the distribution of benzotriazoles in the estuaries of different rivers of central Europe and in the North Sea was analyzed by solid-phase extraction (SPE) and liquid chromatography-mass spectrometry (HPLC-MS/MS). BT as well as TT was detected in all water samples. The concentrations for total benzotriazoles (BTs) ranged from 1.7 to 40 ng/L in the North Sea in costal areas. Concentrations in rivers are from 200 to 1250 ng/L, respectively. The mass flux of total benzotriazoles from the major rivers of central Europe into the North Sea was calculated to 78 t/a, dominated by the Rhine with an individual flux of 57 t/a of BTs. The analysis of the distribution profile in the North Sea showed that the decrease of the concentration was mostly caused by dilution and that the benzotriazoles are poorly degradable in the North Sea. This paper presents the first report of benzotriazoles in the marine environment.     

Measuring Relevance in Support of Design Reuse from Archives of Building Product Models

This paper investigates the use of text analysis techniques to measure relevance between objects in product models. This relevance measure is used to support design reuse from an archive of product models from previous projects. We consider several techniques from the field of information retrieval for comparing documents. Next, we explore whether we can improve the performance of the relevance measure by considering contextual building model elements. The paper concludes with an evaluation and discussion of the techniques considered. We conclude that relatively good retrieval results can be achieved with short texts and sparse building models such as those that occur in current industry practice.     

Briefe Emmy Noethers and P.S. Alexandroff

There are only five letters and two postcards which were written by Emmy Noether to P.S. Alexandroff that have been preserved. These will be edited in this paper. More than any other source, these letters and postcards give an insight into Emmy Noether's privacy, and her sympathy for the problems of her pen pal and colleagues. They illuminate her judgement of different colleagues, students, «mathematical grandchildren» and their papers. They also inform about relationships within the mathematicians' community and the working atmosphere in Goettingen and the US after 1933.

The author thanks Prof. Dr. Walter Purkert, Bonn, for the reference to the writings of Emmy Noether, and Prof. Dr. Albert Shiryaev, Moscow, for the kind publication permission.

     

A note on the internal consistency of the Manifest Needs Questionnaire.

Reviews certain psychometric properties of the Manifest Needs Questionnaire as reported in 8 published studies. In addition, data from 2 new samples are summarized. It is concluded that estimates of internal consistency associated with the needs for achievement, affiliation, and autonomy are not generally satisfactory for use in organizational research. Only the Need for Dominance scale demonstrates a minimally useful degree of internal consistency across all reported studies. (13 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Differences in visual perception and in visual-motor functioning between psychotic and nonpsychotic children.

The study explored the applicable scope of Bender's theory of a "maturational lag" in functional childhood psychosis. Tests of visual perception, visual-motor performance, and a clinical evaluation of presence of CNS deviations consistent with Bender's criteria for childhood schizophrenia were performed on 39 psychotic and 57 nonpsychotic 8-12-year-old boys. Results revealed no differences in accuracy or variability of perceptual and visual-motor behavior when appropriate controls for large group differences in MA functioning were instituted. No difference in test performance was found between psychotic Ss with and without CNS deviations. With MA level constant, the difference in incidence of CNS deviations between psychotics and nonpsychotics was nonsignificant. The results were interpreted as not supporting Bender's organic theory. (19 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)