Trennung von Muskelprotein, Kollagen und Elastin durch fraktionierte Extraktion mit Na-dodecylsulfat(SDS)-L?sungen

Zusammenfassung Die fraktionierte Extraktion mit Na-dodecylsulfat(SDS)-Lösungen ermöglicht die Trennung von Muskel- und Bindegewebs-Protein. In einem zweiten Schritt kann auch Kollagen von Elastin getrennt werden. Muskelprotein löst sich unter Schütteln bei Zimmertemperatur in einer SDS(2%)-ME(1%)-Lösung in einem Boratpuffer pH 9. Zur Lösung des Kollagens sind 100°C, intensives Rühren und eine SDS(8%)-ME(1%)-Lösung in einem Citratpuffer pH 5 notwendig. Das Verfahren wurde an nativem und hitzedenaturiertem Material angewendet. Die Möglichkeit zur Bestimmung des BEFFE-Wertes in Brühwürsten mit dieser Methode wird untersucht und die Anwendung auf andere Fleischprodukte diskutiert.

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Fractionation of muscle protein, collagen and elastin by extraction with buffers containing dodecylsulfat (SDS)

Summary Dodecylsulfate (SDS) containing buffers were used for stepwise extraction of proteins from muscle and connective tissue. The first step was done at room temperature with borate buffer pH 9 and the muscle proteins were extracted. The second treatment (citrate buffer pH 5 at 100°C) dissolved collagen and left elastin as residue. All extracts were analysed by electrophoresis to identify the proteins and evaluated by a biuret method insensitive to SDS and ME. This method was applied to native and heatdenatured proteins and to Brühwdrste. The possibility of applying this method to the determination of the BEFFE-content is discussed.

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Benutzte Abkürzungen NPN Nichteiweißstickstoffverbindungen - ATM Acetontrockenmasse - BEFFE bindegewebseiweißfreies Fleischeiweiß - OH-Pro Hydroxyprolin - SDS Natrium(Sodium)-dodecylsulfat - ME 2-Mercapto-äthanol - Tris Tris-(hydroxymethyl)aminomethan - PAGE Polyacrylamid-Gelelektrophorese - Vk Variationskoeffizient - S Standardabweichung - Mittelwert Die Arbeit ist Teil der Dissertation von I. de WreedeWir danken der Deutschen Forschungsgemeinschaft für ihre finanzielle Unterstützung und Herrn Dr. H. H. Heinert, Leiter des Staatl. Veterinär-Untersuchungsamtes Braunschweig, der freundlicherweise die Brühwurstproben zur Verfügung gestellt hat     

Neue Triterpens?uren der Weintraubenschale

Zusammenfassung Die Cuticula von Traubenschalen enthält neben Oleanolsäure noch 3-Oxo-olean-12-en28-säure, 3-Hydroxi-olean-12-en-28-aldehyd, 3,29-Dihydroxi-olean-12-en-28-säure sowie zwei bisher unbekannte Triterpensäuren. Ihre Strukturen werden durch spektroskopische Daten als 16-Hydroxi-3-oxo-olean-12-en-28-säure und 16-Hydroxi-3-oxo-oleana-1,12-dien-28-säure belegt.

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New triterpenic acids from the peel of grapes

Summary The grape-cuticle contains beside oleanolic acid, 3-oxo-olean-12-en-28-oic acid, 3-hydroxy-olean-12-en-28-aldehyde, 3,29-dihydroxy-olean-12-en-28-oic acid, and two yet hitherto unknown triterpenic acids. Their structures have been elucidated by spectroscopic methods to be l6-hydroxy-3-oxo-olean-12-en-28-oic acid and 16-hydroxy-3-oxo-oleana-1,12-dien-28-oic acid.

     

Die Mikroflora des Sauerteiges

Zusammenfassung Es wurden Ermittlungen über das Vitaminbedürfnis der an der Sauerteiggdrung beteiligten Milchsäurebakterien der UntergattungenThermobacterium, Streptobacterium andBetabacterium angestellt.Von den überprüften Sauerteigbakterien waren 54 Stämme aus sog. Reinzuchtsauerteigen und 49 Stämme aus Sauerteigen isoliert worden. Alle Sauerteigbakterien erwiesen sich biotin-, vitamin B₆-, vitamin B₁₂-, pyridoxamin- und pyridoxalautotroph. Ohne Ausnahme besteht bei den Sauerteigbakterien ein Bedürfnis an Pantothensäure und Nicotinsäure. Die Bedürftigkeit der Sauerteigbakterien an Folsäure, Vitamin B₂ und Vitamin B₁ ist von Art zu Art wechselnd.Das Vitaminbedürfnis der verschiedenen Gruppen von Sauerteigbakterien steht weitgehend in Übereinstimmung mit dem Bedürfnis der jeweils zum Vergleich herangezogenen Milchsäurebakterien definierter Art. Die Befunde geben somit eine Bestätigung der anhand des Zuckerspektrums vorgenommenen Zuordnung der Sauerteigbakterien zu den ArtenLactobacillus aeidophilus, L. casei, L. plantarum, L. fareiminis, L. brevis, L. brevis var. lindneri, L. fermentum undL. fructivorans.

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The microflora of sourdoughV. Communication: The vitamin requirement of lactic acid bacteria (Genus lactobacillus Beijerinck) of sourdough starter and sourdough

Summary Research was carried out on the vitamin requirements of lactic acid bacteria of the subgeneraThermobacterium, Streptobacterium andBetabacterium, which have a part in the sourdough fermentation. Of the investigated sourdough bacteria 54 strains were isolated from the Reinzuchtsauer (a starter culture) and 49 strains from sourdough. All sourdough bacteria were biotin-, vitamin B₆-, vitamin B₁₂-, pyridoxamine-and pyridoxal-autotroph. All sourdough bacteria showed a requirement for pantothenic acid and nicotinic acid. The requirement of sourdough bacteria for folic acid, vitamin B₂ and vitamin B₁ varied from species to species. The vitamin requirements of the different species of sourdough bacteria mostly agree with the requirements of reference strains of lactic acid bacteria (ATCC-strains, DSM-strains) with which they were compared. The results are therefore a confirmation for having assigned the sourdough bacteria from their sugar fermentation reactions to the speciesLactobacillus acidophilus, L. casei, L. plantarum, L. farciminis, L. brevis, L. fermentum, L. fructivorans andL. brevis var. lindneri.

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Nr. 4470 der Veröffentlichungen der Bundesforschungsanstalt für Getreide- und Kartoffelverarbeitung, Detmold

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Diese Untersuchungen wurden ermöglicht durch eine finanzielle Förderung seitens des Bundesministeriums für Forschung und Technologie im Rahmen des Programmes Biologie und Technik     

Selecting scientific excellence through committee peer review - A citation analysis of publications previously published to approval or rejection of post-doctoral research fellowship applicants

Summary We investigated committee peer review for awarding long-term fellowships to post-doctoral researchers as practiced by the Boehringer Ingelheim Fonds (B.I.F.) - a foundation for the promotion of basic research in biomedicine. Assessing the validity of selection decisions requires a generally accepted criterion for research impact. A widely used approach is to use citation counts as a proxy for the impact of scientific research. Therefore, a citation analysis for articles published previous to the applicants' approval or rejection for a B.I.F. fellowship was conducted. Based on our model estimation (negative binomial regression model), journal articles that had been published by applicants approved for a fellowship award (n = 64) prior to applying for the B.I.F. fellowship award can be expected to have 37% (straight counts of citations) and 49% (complete counts of citations) more citations than articles that had been published by rejected applicants (n = 333). Furthermore, comparison with international scientific reference values revealed (a) that articles published by successful and non-successful applicants are cited considerably more often than the “average” publication and (b) that excellent research performance can be expected more of successful than non-successful applicants. The findings confirm that the foundation is not only achieving its goal of selecting the best junior scientists for fellowship awards, but also successfully attracting highly talented young scientists to apply for B.I.F. fellowships.     

A Noninformative Prior for Neural Networks

While many implementations of Bayesian neural networks use large, complex hierarchical priors, in much of modern Bayesian statistics, noninformative (flat) priors are very common. This paper introduces a noninformative prior for feed-forward neural networks, describing several theoretical and practical advantages of this approach. In particular, a simpler prior allows for a simpler Markov chain Monte Carlo algorithm. Details of MCMC implementation are included.     

Explaining Paradoxical Relations Between Academic Self-Concepts and Achievements: Cross-Cultural Generalizability of the Internal/External Frame of Reference Predictions Across 26 Countries.

The internal/external frame of reference (I/E) model explains a seemingly paradoxical pattern of relations between math and verbal self-concepts and corresponding measures of achievement, extends social comparison theory, and has important educational implications. In a cross-cultural study of nationally representative samples of 15-year-olds from 26 countries (total N = 55,577), I/E predictions were supported in that (a) math and verbal achievements were highly correlated, but math and verbal self-concepts were nearly uncorrelated; (b) math achievement had positive effects on math self-concept, but negative effects on verbal self-concept; and (c) verbal achievement had positive effects on verbal self-concept, but negative effects on math self-concept. Supporting the cross-cultural generalizability of predictions, multigroup structural equation models demonstrated good support for the generalizabilify of results across 26 countries participating in the Programme for International Student Assessment project sponsored by the Organisation for Economic Co-operation and Development. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Behavioral medicine, clinical health psychology, and cost offset.

The use of medical services is a function of several interacting psychological and social variables as well as a function of physical malfunction. The clinical significance of addressing patients' psychosocial issues has only occasionally been considered. However, the shift in health care economics toward health care maintenance is responsible for the increased interest in interventions in the domain of behavioral medicine and health psychology. Evidence is reviewed for 6 mechanistic pathways by which behavioral interventions can maximize clinical care and result in significant economic benefits. The rationale for further integration of behavioral and biomedicine interventions is also reviewed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Soft-Decoding SOM for VQ Over Wireless Channels

A self-organizing map (SOM) approach for vector quantization (VQ) over wireless channels is presented. We introduce a soft decoding SOM-based robust VQ (RVQ) approach with performance comparable to that of the conventional channel optimized VQ (COVQ) approach. In particular, our SOM approach avoids the time-consuming index assignment process in traditional RVQs and does not require a reliable feedback channel for COVQ-like training. Simulation results show that our approach can offer potential performance gain over the conventional COVQ approach. For data sources with Gaussian distribution, the gain of our approach is demonstrated to be in the range of 1–4 dB. For image data, our approach gives a performance comparable to a sufficiently trained COVQ, and is superior with a similar number of training epoches. To further improve the performance, a SOM–based COVQ approach is also discussed.     

Design and structural applications of stress-crack width relations in fibre reinforced concrete

The stress-crack width relationship has been shown to be the key to an understanding of fracture propagation in and mechanical behaviour in tension of fibre reinforced concrete materials and structures. A model is derived for the stress-crack width relationship for randomly oriented short fibre composites which takes hybrid fibre systems and possible fibre rupture into account. It is shown how this stress-crack width relationship can be included in a structural model for the prediction of crack widths in reinforced concrete structures. With this combination of models a rational design tool for the design of composite materials and structures has been established. It is shown how different fibre systems can be tested for structural applicability and how combined material and structural optimization can take place.