Eta-prime quark-antiquark and eta-prime NN vertex suppression in effective theories

In an effective theory containing only quark degrees of freedom, such as the extended Nambu-Jona-Lasinio model, the influence of the axial anomaly can be incorporated by a self-interaction of the 't Hooft determinant type. I will show that despite the theshold problem related to the eta-prime meson this leads to a significant suppression of the eta-prime coupling g_{\eta' q \bar{q}} to dynamical quarks which suggests a suppression of the eta-prime-NN vertex as compared to the eta-NN vertex.Comment: 2 pages, 2 encapsulated postscript figures, latex2e uses svjour.cls, graphics, epsfig, amsmath; shortend versio

Does the Mobility of Football Players Influence the Success of the National Team?

This paper is motivated by the observation that there is a large discrepancy among football nations regarding the number of football players that play in the national team and also in their home league. Two extreme examples are Argentina and Italy : Almost all members of the national team of Argentina play in a foreign football league and all national team players of Italy play in their home league. We focus on the question whether a country's success in international competitions significantly depends on the mobility of its football players. More specifically, we analyze whether a country's success is influenced (i) by the number of national team players that do not play in the home league and (ii) by the number of national team players from other countries that play in the home league. Our study is based on data of all 32 national football teams qualified for the FIFA World Cup in Germany 2006 including more than 700 players with a total estimated market value of almost four billion Euros. The main finding is that a country's success crucially depends on both imports and exports. This suggests that all countries that qualified for the World Cup gain from trade.football, international trade, transfer market

Design of a bubble-swarm bioreactor for animal cell culture

Gudermann F, Lütkemeyer D, Lehmann J. Design of a bubble-swarm bioreactor for animal cell culture. Cytotechnology. 1994;15(1-3):301-309.A stationary bubble-swarm has been used to aerate a mammalian cell culture bioreactor with an extremely low gas flow rate. Prolonging the residence time of the gas bubbles within the medium improved the efficiency of the gas transfer into the liquid phase and suppressed foam formation. An appropriate field of speed gradients prevented the bubbles from rising to the surface. This aeration method achieves an almost 90% transfer of oxygen supplied by the bubbles. Consequently, it is able to supply cells with oxygen even at high cell densities, while sparging with a gas flow of only 0.22 x 10(-3) -1.45 x 10(-3) vvm (30-200 ml/h). The reactor design, the oxygen transfer rates and the high efficiency of the system are presented. Two repeated batch cultures of a rat-mouse hybridoma cell line are compared with a surface-aerated spinner culture. The used cell culture medium was serum-free, either with or without BSA and did not contain surfactants or other cell protecting agents. One batch is discussed in detail for oxygen supply, amino acid consumption and specific antibody production

Modelling of a naturally ventilated BIPV system for building energy simulations

Two major causes of energy yield reduction in PV systems are partial shading and high operating temperatures. Both issues are particularly critical for BIPV systems. The correct assessment of the BIPV contribution to the built environment depends, therefore, on the accurate prediction of PV temperature and on the possibility of simulating shading effects. This paper describes the development of a multi-physics model for a naturally ventilated façade BIPV system within the openIDEAS environment for building and district energy simulations. The PV electrical model used here follows a physics-based approach that takes into account solar intensity and temperature spatial variations within the PV module, enabling the simulation of shading effects both at cell and module level. A detailed thermal model has been developed and coupled to the electrical model to estimate the PV temperature. Four case studies illustrate the importance of temperature and shading effects on the PV power output. The model has been validated using data from an experimental BIPV setup deployed in Belgium. The results indicate that the model is able to predict both the PV surface temperature and the power production, given the correct boundary conditions are applied

Rapid high-performance liquid chromatographic quantification of recombinant human antithrombin III during production and purification

Büntemeyer H, Tebbe H, Lütkemeyer D, Lehmann J. Rapid high-performance liquid chromatographic quantification of recombinant human antithrombin III during production and purification. Journal of Chromatography, B: Biomedical Sciences and Applications. 1994;662(2):209-216.For monitoring of recombinant human antithrombin III during cell culture processes and subsequent purification steps a rapid method for quantitative determination was developed. The need for the introduction of this rapid method came from the limited availability of a quantitative enzyme-linked immunosorbent assay (ELISA) and the very time-consuming ELISA procedure. The developed method is based on reversed-phase high-performance liquid chromatography using a C 4 column. The separation by gradient elution using water and acetonitrile takes less than 20 min even when complex samples, such as serum containing cell culture samples, have to be analyzed. Automation and a high sample throughput are possible with this reliable method. If necessary, insulin, transferrin and albumin can also be quantified with minor changes of the elution profile

11th EEEIC International Conference on Environment and Electrical Engineering – Student Edition : Wrocław-Ostrava-Cottbus 7th - 12th of May 2012

In the time of increased awareness about the environment problems by the public opinion and also intensive international efforts to reduce emissions of greenhouse gases, as well increase of the generation of electrical energy to facilitate industrial growth, the conference offers broad contribution towards achieving the goals of diversification and sustainable development. Focus of the student conference is to promote the discussion of views from scientists and students from Wroclaw University of Technology, Technical University of Ostrava and Brandenburg Technical University of Cottbus. The conference offers prominent academics and industrial practitioners from all over the world the forum for discussion about the future of electrical energy and environmental issues and presents a base for identifying directions for continuation of research

Re-use of spent cell culture medium in pilot scale and rapid preparative purification with membrane chromatography

Riese U, Lütkemeyer D, Heidemann R, Büntemeyer H, Lehmann J. Re-use of spent cell culture medium in pilot scale and rapid preparative purification with membrane chromatography. Journal of Biotechnology. 1994;34(3):247-257.Based on experiments in bench scale, a recycling of spent cell culture medium was performed in a 100-l pilot scale bioreactor. The cell cultivation has been done as a repeated batch procedure after the initial batch in the following four repeated batches spent medium from the previous batch was partially re-used. After microfiltration and ultrafiltration a part of the filtrate was mixed with a concentrate of amino acids and glucose, sterile filtered and subsequently filled back into the bioreactor. Up to 65% of the harvested cell- and product-free spent medium was re-used in each repeated batch. This procedure results in a saving of pure and waste water volume and saving of supplemented proteins as transferrin, insulin and lipoproteins and, therefore, also in a reduction of the production costs. A strongly acidic membrane ion exchanger was evaluated for the ability to purify the monoclonal antibodies from the pilot scale cultivation. Within minutes, gram quantities of product could be purified in a high flux system, especially developed for this purpose, achieving purities of 80%. The capacity of the acidic membrane ion exchanger was found in former investigations to be 1 mg cm -2 with recoveries up to 96%. Final purification was carried out by gel column filtration