Electrophoretic and immunochemical determination of bioindustrial enzymes in apple juice

The present study was undertaken to develop a specific and sensitive method which allows the detection of trace amounts of the potentially allergenic bioindustrial enzymes Pectinex Ultra-SPL (pectinase) and Gamylo 200L (amylase) in apple juice. This was achieved by an immunoblotting procedure based on sodium dodecyl sulfate (SDS) electrophoretic separation, followed by an immunochemical detection step using polyclonal rabbit antisera directed against these enzymes and, secondly, alkaline phosphatase labelled antibodies in combination with a highly sensitive enhanced chemiluminescent (ECL) detection method. In a juice spiked with enzyme at various concentrations between 10,000 and 1 ppm (1.0-0.0001%), the detection limit was 10 ppm (=0.001%) for Pectinex Ultra-SPL and 1 ppm (=0.0001%) for Gamylo 200L, respectively. Since the enzyme preparations contain less than 5% of enzymes, the detection limit for the pure enzymes is markedly lower, at least below 1 ppm. Whereas in the samples withdrawn during the initial stages of the industrial production process of apple juice, Pectinex Ultra-SPL and Gamylo 200L components were detectable in concentrations between 50 and 100 ppm, after clearing, ultrafiltration and pasteurization, neither pectinase nor amylase was detectable in the final consumer's product. Under the conditions employed, the bioindustrial enzymes Pectinex Ultra-SPL and Gamylo 200L were virtually removed during the course of production. The risk of sensitizing consumers by intake of apple juice seems to be marginal. This view is supported by the results of an animal model (anaphylaxis test), in which neither gastro-enteral reactions in guinea pigs and mice, nor IgE or IgG production by orally feeding these animals with apple juice concentrate, could be induced.     

Entwicklung und Erprobung eines Verfahrens zur Untergrundentsäuerung von Kippengrundwässern

Sulfate-reducing processes were initiated in an aquifer with AMD-laden groundwater orthogonally to the located main groundwater flow direction. Groundwater was intermittently circulated between two wells. Substrate (methanol) and nutrients were added to this flow. After one year a sulphate-reducing reactor was formed in the aquifer, that precipitated FeS and decreased the acidity. These effects could still be observed one year after cessation of substrate amendment.     

Simple colorimetric method for quantification of surface carboxy groups on polymer particles

We present a novel, simple, and fast colorimetric method to quantify the total number of carboxy groups on polymer microparticle and nanoparticle surfaces. This method exploits that small divalent transition metal cations (M(2+) = Ni(2+), Co(2+), Cd(2+)) are efficiently bound to these surface functional groups, which allows their extraction by a single centrifugation step. Remaining M(2+) in the supernatant is subsequently quantified spectrophotometrically after addition of the metal ion indicator pyrocatechol violet, for which Ni(2+) was identified to be the most suitable transition metal cation. We demonstrate that the difference between added and detected M(2+) is nicely correlated to the number of surface carboxy groups as determined by conductometry, thereby affording a validated measure for the trueness of this procedure. The variation coefficient of ~5% found in reproducibility studies underlines the potential of this novel method that can find conceivable applications for the characterization of different types of poly(carboxylic acid)-functionalized materials, e.g., for quality control by manufacturers of such materials.     

Influence of dynamic stimulation,visual perception and individual susceptibility to car sickness during controlled stop-and-go driving

Forschung im Ingenieurwesen - The enjoyment and usage of highly automated vehicles might be reduced by motion sickness. This study addresses the influencing factors of dynamic stimulation, visual...     

Role of social desirability in personality testing for personnel selection: The red herring.

Response bias continues to be the most frequently cited criticism of personality testing for personnel selection. The authors meta-analyzed the social desirability literature, examining whether social desirability functions as a predictor for a variety of criteria, as a suppressor, or as a mediator. Social desirability scales were found not to predict school success, task performance, counterproductive behaviors, and job performance. Correlations with the Big Five personality dimensions, cognitive ability, and years of education are presented along with empirical evidence that (a) social desirability is not as pervasive a problem as has been anticipated by industrial-organizational psychologists, (b) social desirability is in fact related to real individual differences in emotional stability and conscientiousness, and (c) social desirability does not function as a predictor, as a practically useful suppressor, or as a mediator variable for the criterion of job performance. Removing the effects of social desirability from the Big Five dimensions of personality leaves the criterion-related validity of personality constructs for predicting job performance intact. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Entwurf von Flüssigkeitsbehältern

Design of Liquid Retaining Structures – Remarks on the Rules of the Guideline “Watertight Concrete” The use of watertight concrete structures is regulated by the guideline “Watertight Concrete” of the German Committee of Reinforced Concrete, especially requirements on the serviceability limit states. The scope of the guideline is valid for liquid retaining structures too. The essential characteristic of those structures is their defined tightness. Design concepts in order to fullfill requirements on durability of concrete tanks are discussed. Moreover, recommendations due to the design of moderate prestressed reinforced concrete tanks are given, containing the durable filling of planned cracks. Design aspects of the European Standard EC 2 Part 3 are discussed too.     

Membranbrennstoffzellen

With the development of polymer membranes suitable as proton‐conducting electrolytes, membrane fuel cells are now successfully applied in various areas. Depending on the application, the service life, the power density or other system aspects are optimized. Common to all applications is the requirement to reduce costs, which, however, plays a decisive role especially in passenger cars. The development of the membrane fuel cell has now reached a high technical level, but political flanking measures are still required to launch it on the market. This applies both to the hydrogen infrastructure for fuel cell vehicles and to the promotion of fuel cell‐based combined heat and power generation.