Nano-spheres stabilized poly(vinyl phosphonic acid) as proton conducting membranes for PEMFCs

Poly(4-vinyl pyridine) nano-spheres (P4VP-NS) stabilized poly(vinyl phosphonic acid) (PVPA) membranes were prepared as proton conducting membranes for fuel cells. The acid–base interactions between P4VP-NS and PVPA were utilized to improve the dimensional and thermal stability of PVPA. In this work, the effects of acid–base interactions on proton conductivity and thermal stability were quantitatively determined and discussed based on the results of ¹H magic-angle-spin NMR (¹H MAS NMR), Fourier transfer infrared spectroscopy (FTIR) and impedance spectroscopy measurements.     

Teradata University Network — Ein Portal zur Unterstützung der Lehre in den Bereichen Business Intelligence, Data Warehousing und Datenbanken

Business intelligence and information logistics have become a part of teaching curricula in recent years due to their importance for companies and the request for adequately trained graduates. Since these fields are characterized by a high amount of software and methodology innovations, teaching materials and teaching aids require constant attention. Teradata, a division of NCR Corp., has teamed up with lecturers and researchers to build and run a portal to support teaching business intelligence and information logistics. This article describes how faculty can use the Teradata University Network to prepare and run courses by reusing teaching materials and running state-of-the-art, commercial software provided in an ASP model.     

Partially decoupled approach of extended non-minimal state space predictive functional control for MIMO processes

This paper presents a partially decoupled design of the state space predictive functional control for MIMO processes. The multivariable process is first treated into MISO process by a simple Cramer's rule solution to linear equations which provides a balance between model complexity and control system design, and then the derived MISO process based extended state space predictive functional control is presented. The overall design of the controller enables the controller to consider both the process state dynamics and the output dynamics, thus improved control performance for tracking set-points and disturbance rejection is resulted. The proposed controller is tested on both model match and model mismatch cases to demonstrate its superiority. In addition, a closed-form of transfer function representation that facilitates frequency analysis of the control system is provided to give further insight into the proposed method.     

Cell function in the bovine mammary gland: a preliminary study on interdependence of healthy and infected udder quarters

Udder defence mechanisms are not completely explained by current mastitis research. The anatomical construction of the udder implies that infection of one udder quarter does not influence the immune status of neighbouring quarters. To test this hypothesis, we compared the immune reactions of individual udder quarters in response to microbial attacks. In the course of immune reactions, polymorphonuclear leucocytes (PMN) release oxygen radicals, which can be determined by chemiluminescence (CL). Milk from 140 udder quarters of 36 cows was analysed for somatic cell count (SCC), differential cell count, viability and CL activity. Quarters with an SCC < 100,000 cells/ml and free of pathogens were defined as uninfected, all other quarters were categorized as infected. Three groups of cows were classified cytologically: group A (healthy, 11 animals, SCC limit < 100,000 cells/ml); group B (moderate mastitis, 8 cows, SCC > or = 100,000 and < 400,000 cells/ml in at least one quarter); and group C (severe mastitis, 17 cows, SCC > or = 400,000 cells/ml in at least one quarter). Infected and uninfected quarters in groups B and C were analysed separately. Viability of PMN leucocytes was significantly (P=0.0012) lower in group A (72.6%) than in healthy quarters of group C (84.0%). Lowering the SCC limit of healthy quarters to <50,000 cells/ml (group A: all quarters within the udder) revealed striking differences between samples of groups B and C: in addition to varying differential cell counts and viabilities, CL activity of group B<50 (2929 CL units/million PMN) was markedly lower than that of the other groups (5616 in group A<50 and 6445 CL units/million PMN in group C<50). These results allow the conclusion that the infection of one udder quarter influences the cell activity of neighbouring quarters. When the SCC threshold for healthy quarters was reduced to 50,000 cells/ml, greater differences in cell activities were detected between healthy udders and healthy quarters of infected udders.     

Microbial dehalogenation of trichlorinated dibenzo-p-dioxins by a Dehalococcoides-containing mixed culture is coupled to carbon isotope fractionation

An anaerobic enrichment culture reductively dehalogenated 1,2,4- and 1,2,3-trichlorodibenzo-p-dioxin (TrCDD) almost exclusively at peripheral positions forming the main products 1,3-dichloro-(DiCDD) and 2-monochlorodibenzo-p-dioxin (MCDD) from 1,2,4-TrCDD and 2,3-DiCDD from 1,2,3-TrCDD. Dehalococcoides was monitored in the mixed culture by quantitative real-time PCR. A yield of 2.5 x 10(8) to 2.75 x 10(8) copies of 16S rRNA genes per micromole of chloride released suggested growth by dehalorespiration with dibenzo-p-dioxins. For the analysis of carbon isotope fractionation, the dioxin congeners were isolated by solid-phase microextraction (SPME) from the headspace of the cultures. The delta13C composition of 1,2,4-TrCDD did not change remarkably during the course of reductive dehalogenation; however, the intermediate 1,3-DiCDD became enriched, and the final product 2-MCDD significantly depleted in 13C with a discrimination of 2.5-3.6 per thousand between 1,3-DiCDD and 2-MCDD. 1,2,3-TrCDD and its main product 2,3-DiCDD became slightly enriched in 13C, whereas the formed low concentrations of 2-MCDD were depleted in 13C by 5.5-4.8 per thousand. This study demonstrates carbon isotope fractionation during sequential reductive dehalogenation of chlorinated dibenzo-p-dioxins, whereby isotope fractionation upon dehalogenation of the intermediate was substantial. This can provide a basis for the development of a new method to monitor the fate of dioxins in the environment using compound specific stable isotope analyses.     

Molecular genetics of 6-phosphofructokinase in Pichia pastoris

Previously, studies on glucose-induced microautophagy in the methylotrophic yeast Pichia pastoris provided evidence that the glucose-induced selective autophagy-1-protein is the alpha-subunit of 6-phosphofructokinase (Pfk), a key enzyme in the glycolytic pathway. In our work, we could clearly demonstrate that two types of subunits of Pfk exist in P. pastoris. Investigating the yeast cell-free extract by Western blot analysis, two distinct signals of Pfk were obtained. In addition, we isolated a DNA sequence containing the complete ORF of PpPFK2 encoding the beta-subunit of Pfk from P. pastoris with a deduced molecular mass of 103.7 kDa. On the basis of these results, a hetero-oligomeric structure of Pfk in P. pastoris became obvious. Because the molecular and kinetic properties of a homo-oligomeric yeast Pfk appear to be more similar to those of mammalian Pfk, as described in the literature, our results are of interest for the growing number of studies on P. pastoris as a heterologous production system. Furthermore, the 3'- and 5'-non-coding regions of PpPFK2 were isolated and several putative binding sites for regulatory factors could be identified in the promoter region.     

The influence of different nitrogen and carbon sources on mycotoxin production in Alternaria alternata

The aim of this study was to determine the influence of different carbon and nitrogen sources on the production of the mycotoxins alternariol (AOH), alternariol monomethyl ether (AME) and tenuazonic acid (TA) by Alternaria alternata at 28 °C using a semi-synthetic medium (modified Czapek-Dox broth) supplemented with nitrogen and carbon sources. Additionally the effect of shaken and static cultivation on mycotoxin production was tested. Initial experiments showed a clear dependency between nitrogen depletion and mycotoxin production. To assess whether nitrogen limitation in general or the type of nitrogen source triggers the production, various nitrogen sources including several ammonium/nitrate salts and amino acids were tested. In static culture the production of AOH/AME can be enhanced greatly with phenylalanine whereas some nitrogen sources seem to inhibit the AOH/AME production completely. TA was not significantly affected by the choice of nitrogen source. In shaken culture the overall production of all mycotoxins was lower compared to static cultivation. Furthermore tests with a wide variety of carbon sources including monosaccharides, disaccharides, complex saccharides such as starch as well as glycerol and acetate were performed. In shaken culture AOH was produced when glucose, fructose, sucrose, acetate or mixtures of glucose/sucrose and glucose/acetate were used as carbon sources. AME production was not detected. The use of sodium acetate resulted in the highest AOH production. In static culture AOH production was also stimulated by acetate and the amount is comparable to shaken conditions. Under static conditions production of AOH was lower except when cultivated with acetate. In static cultivation 9 of 14 tested carbon sources induced mycotoxin production compared to 4 in shaken culture. This is the first study which analyses the influence of carbon and nitrogen sources in a semi-synthetic medium and assesses the effects of culture conditions on mycotoxin production by A. alternata.     

Posttraumatic stress disorder following political imprisonment: The role of mental defeat, alienation, and perceived permanent change.

An interview study of 81 former political prisoners investigated whether posttraumatic stress disorder (PTSD) is related to the way individuals process the prison experience. In contrast to participants without PTSD, those with chronic or remitted PTSD were more likely to perceive mental defeat and an overall feeling of alienation from other people. Chronic PTSD was also related to perceived negative and permanent change in their personalities or life aspirations. The groups did not differ in their attempts to gain control during imprisonment. Evidence for a relationship between political commitment and PTSD was mixed. The results suggest that mental defeat, alienation, and permanent change are related to PTSD after interpersonal trauma and may need to be addressed in treatment. (PsycINFO Database Record (c) 2010 APA, all rights reserved)