Der Arbeitskreis “Punktgestützte Verglasungen” im FKG

The working group “point fittings” of FKG. A working group within the FKG deals with glass under local stress caused by point fittings and concentrated loads. At the moment there are two major issues: glass under shear bearing loads and calculation of regular point fixed glass. The first item is relevant for the innovative use of glass as a load bearing part of the structure. The second item is about finding a save concept of verifying FE models and calculating the common point fitted glass to support the making of a standard practise for Engineering and Design of point‐fixed glass.     

Blended Learning – ein innovatives Weiterbildungskonzept für die Technische Chemie

The ever‐increasing and ever‐changing challenges of the job market require professionals to constantly attend extra occupational education programs. Professionals furthermore express their desire for a compatibility of family and work. Therefore, a general concept for extended vocational training in the field of natural science and technology was developed based on blended learning. As an example, the concept was implemented and tested on the basis of the extended vocational training course “tc‐compact^BL” in Chemical Technology.     

Effects of ethanol,formaldehyde, and gentle heat fixation in confocal resonance Raman microscopy of purple nonsulfur bacteria

Resonance Raman microscopy is well suited to examine living bacterial samples without further preparation. Therefore, comparatively little thought has been given to its compatibility with common fixation methods. However, fixation of cell samples is a very important tool in the microbiological sciences, allowing the preservation of samples in a specific condition for further examination, future measurements, transport, or later reference. We examined the effects of three common fixatives—ethanol, formaldehyde solution, and gentle heat—on the resonant Raman spectrum of three generic bacteria species, Rhodobacter sphaeroides DSM 158^T, Rhodopseudomonas palustris DSM 123^T, and Rhodospirillum rubrum DSM 467^T, holding carotenoid‐ and heme‐chromophores in confocal Raman microscopy. In addition, we analyzed the effect of poly‐L ‐lysine coating of microscope slides, widely used for mounting biological and medical samples, on subsequent confocal Raman measurements of native and fixed samples. The results indicate that ethanol is preferable to formaldehyde as fixative if applied for less than 24 h, whereas heat fixation has a strong, detrimental effect on the resonant Raman spectrum of bacteria. Formaldehyde fixation excels at fixation times above 24 h, but causes an overall reduction in signal intensity. Poly‐L ‐lysine coating has no discernable effect on the Raman spectra of samples fixed with ethanol or heat, but it further decreases the signal intensity, especially at higher wavenumbers, in the spectra of samples fixed with formaldehyde. Microsc. Res. Tech. 74:177–183, 2011. © 2010 Wiley‐Liss, Inc.     

Growth kinetics and stable carbon isotope fractionation during aerobic degradation of cis-1,2-dichloroethene and vinyl chloride

Assessing changes in the isotopic signature of contaminants is a promising new tool to monitor microbial degradation processes. In this study, chloroethene degradation was proven by depletion of chloroethenes, formation of chloride, increase in protein content and stable carbon isotope fractionation. Aerobic degradation of vinyl chloride (VC) was found to proceed metabolically, with degradation rates of 0.48 and 0.29 d(-1); and growth yields of 9.7 and 6.4 g of protein/mol of VC at room and groundwater temperature, respectively. Cis-1,2-dichloroethene (cDCE) was degraded cometabolically under aerobic conditions when VC was provided as growth substrate. Aerobic degradation was associated with significant stable carbon isotope fractionation, with enrichment factors ranging from -5.4+/-0.4 per thousand for metabolic degradation of VC to -9.8+/-1.7 per thousand for cometabolic degradation of cDCE. Thus, it was demonstrated that stable carbon isotope fractionation is suitable for assessing aerobic chloroethene degradation, which can contribute significantly to site remediation.     

Biodegradability and ecotoxicity of commercially available geothermal heat transfer fluids

Commercially available heat transfer fluids used in borehole heat exchangers were investigated for their composition, their biodegradability as well as their ecotoxicity. The main components of the fluids are organic compounds (often glycols) for freezing protection. Biodegradation of the fluids in laboratory studies caused high oxygen depletion as well as nitrate/iron(III) reduction under anaerobic conditions. Additives such as benzotriazoles for corrosion protection were persistent. Ecotoxicity data show that the commercially available fluids caused much higher ecotoxicity than their main organic constituents. Consequently, with regard to groundwater protection pure water as heat transfer medium is recommended. The second best choice is the usage of glycols without any additives. Effects on groundwater quality should be considered during ecological-economical cost-benefit-analyses of further geothermal energy strategies. The protection of groundwater as the most important drinking water resource must take priority over the energy gain from aquifers.     

THE RURAL IS NOT REMOTE — THE CASE OF COMPANY DRINKS

The article focuses on the undesirable binary between the rural and the urban and uses Company Drinks as an example of a reverse ruralurban relationship, where an inner city population migrates temporarily to the countryside, which is relevant to the hop-picking tradition (“hopping”) practiced by working-class families from London’s East End. In this case, a working-class community has developed its own rural practice, moving between rural and urban settings on a regular basis. Company Drinks is a new model cultural enterprise that uses the collective memory of hopping as a starting point to rethink and reintroduce an adaptive collective production cycle into East London everyday life. With various successful activities being held, going picking has been far from an East End tradition and become a universal activity recognized and appreciated across different cultures and landscapes. The author believes that rural-urban link cannot be controlled from a distance. Rural society offers knowledge and resource that can empower urban communities, and can test and provide conditions for alternatives to urban lifestyles.     

A rigorous small area modelling-study for the helicobacter pylori epidemiology

This paper presents an investigation into spatial risk differences over small distances for the Helicobacter pylori infection in the city of Leipzig, Germany and two rural districts. A model, using Bayesian inference, was developed that adjusts the risk for individual-specific factors, and for spatial or individual over-dispersion, respectively. Additionally, the model takes into account conditional spatial autocorrelation. We found a significant positive association to the H. pylori infection risk for: “more than three children live in the household” (OR = 2.4, p = 0.001), “more persons live per sq.m than average” (OR = 1.4, p = 0.03), “home situated at main road” (OR = 1.4, p = 0.04) and “using well water” (OR = 2.3, p = 0.05). A protective effect was identified for “travelled to low prevalence region” (OR = 0.4, p < 0.0001) and “born in Germany” (OR = 0.2, p < 0.0001). Three administrative areas with significantly increased spatial risk were identified: one in the rural district and two in the city of Leipzig. The model explained 24.9% of the total deviance. Contrary to expectations, the largest part of deviance of the data was not explained by the identified significant risk factors, but by individual-specific heterogeneities. We conclude that further - so far not discussed - factors influence the risk and the spatial variation of the H.pylori infection. Furthermore, from the results we speculate about a possible impact of long-time air pollution and surface water.     

Stanford-Kaiser Permanente G1 study for clinical stage I to IIA Hodgkin's disease: subtotal lymphoid irradiation versus vinblastine, methotrexate, and bleomycin chemotherapy and regional irradiation

PURPOSE: We have demonstrated that a relatively mild chemotherapy regimen, vinblastine, methotrexate, and bleomycin (VBM), and involved-field radiotherapy (IFRT) could substitute for extended-field radiotherapy in patients with favorable Hodgkin's disease (HD) who have been laparotomy-staged. The purpose of this study is to determine if VBM and regional radiotherapy can substitute for extended-field radiotherapy in favorable clinical stage (CS) I and II HD. PATIENTS AND METHODS: Seventy-eight patients with favorable CS I to II HD were randomly assigned to subtotal lymphoid irradiation (STLI) or VBM chemotherapy and regional radiotherapy. Randomization was stratified on the basis of age, sex, number of Ann Arbor sites, histology, and institution. Patients were evaluated for freedom from progressive HD, survival, and toxicity. Results were compared with the predecessor trial in pathologically staged patients. RESULTS: With a median follow-up period of 4 years, the rate of freedom from progressive HD was 92% (95% confidence interval [CI], 88% to 96%) for patients treated with STLI and 87% (95% CI, 81% to 93%) for patients treated with VBM and regional radiotherapy. Six of seven patients who relapsed are alive and in remission following successful second-line therapy. CONCLUSION: Given the caveat of a small number of patients, the results of extended-field radiotherapy and VBM and regional radiotherapy are comparable with a median follow-up period of 4 years. VBM serves as a paradigm to reduce late effects in favorable early-stage HD. We do not advocate its routine use in clinical practice, but instead encourage participation in clinical trials with the objective of maintaining efficacy while reducing toxicity in CS I and II HD.