Ausschluss, Ablehnung und Annahme von Wissen in den medizinischen Enzyklopädien der Spätantike oder „Negativer Transfer“ at its best

Die spätantike, frühbyzantinische Medizin (4.–7. Jh. n. Chr.) ist vor allem durch die drei Autoren Oribasius von Pergamon, Aetius von Amida und Paulus von Aegina geprägt, die allesamt Werke „enzyklopädischen“ Charakters verfassten. Während sich in der Forschung lange Zeit die Auffassung hielt, dass diese Autoren lediglich altes Material konservierten und abgesehen von dem glücklichen Umstand, dass durch ihre Werke einige Texte früherer Epochen auf uns gekommen sind, die andernfalls gänzlich verloren wären, nicht von Interesse seien, hat es sich mittlerweile etabliert, diese Früchte spätantiker Medizin als eigenständige literarische Produkte zu untersuchen. Diese neuere Forschung hat gezeigt, dass Oribasius, Aetius und Paulus ihre Quellentexte keineswegs nur blind kopiert, sondern durchaus Veränderungen, Neukontextualisierungen und Ergänzungen vorgenommen haben. Vor diesem Hintergrund zeigt der vorliegende Aufsatz anhand ausgewählter Textbeispiele, wie in den medizinischen „Enzyklopädien“ durch Ausschluss, Ablehnung und Annahme von tradiertem Wissen genau dieses Wissen in Bewegung geblieben ist und wie gerade eine Analyse des Zusammenspiels von Wissen, Transfer und Negation hilft, die enorme Eigenleistung dieser spätantiken „Enzyklopädien“ zu erkennen

A comprehensive analysis of the importance of translation initiation factors for Haloferax volcanii applying deletion and conditional depletion mutants

Translation is an important step in gene expression. The initiation of translation is phylogenetically diverse, since currently five different initiation mechanisms are known. For bacteria the three initiation factors IF1 – IF3 are described in contrast to archaea and eukaryotes, which contain a considerably higher number of initiation factor genes. As eukaryotes and archaea use a non-overlapping set of initiation mechanisms, orthologous proteins of both domains do not necessarily fulfill the same function. The genome of Haloferax volcanii contains 14 annotated genes that encode (subunits of) initiation factors. To gain a comprehensive overview of the importance of these genes, it was attempted to construct single gene deletion mutants of all genes. In 9 cases single deletion mutants were successfully constructed, showing that the respective genes are not essential. In contrast, the genes encoding initiation factors aIF1, aIF2γ, aIF5A, aIF5B, and aIF6 were found to be essential. Factors aIF1A and aIF2β are encoded by two orthologous genes in H. volcanii. Attempts to generate double mutants failed in both cases, indicating that also these factors are essential. A translatome analysis of one of the single aIF2β deletion mutants revealed that the translational efficiency of the second ortholog was enhanced tenfold and thus the two proteins can replace one another. The phenotypes of the single deletion mutants also revealed that the two aIF1As and aIF2βs have redundant but not identical functions. Remarkably, the gene encoding aIF2α, a subunit of aIF2 involved in initiator tRNA binding, could be deleted. However, the mutant had a severe growth defect under all tested conditions. Conditional depletion mutants were generated for the five essential genes. The phenotypes of deletion mutants and conditional depletion mutants were compared to that of the wild-type under various conditions, and growth characteristics are discussed

Simulating operational alternatives for future cement production

To support decisions on product and process development options and strategic planning, information on the consequences of planned changes are needed. For this purpose a flexible model for cement manufacturing has been developed. The model predicts the environmental, product and economic performance in a life cycle perspective, simulating different operational alternatives. Interesting future operational alternatives, such as an increase in the use of industrial by-products and wastes as raw materials and fuels have been explored. The results, i.e. the consequences from a life cycle perspective of potential development options, are discussed. The nine simulations show that the use of recovered material and alternative fuel (defined waste) can be increased while maintaining the current requirements on clinker performance. An increase in the use of recovered material and alternative fuel replaces the use of resources. The simulations also show that the emissions of CO 2 , NO X , SO 2 , CO, VOC, CH 4 and dust can be reduced between 30 and 80% depending on the use of recovered material and alternative fuel. The transport of recovered material and alternative fuel increases with increased use. However, the environmental benefits of the increase in use of recovered material and alternative fuel are by far greater than the resource use and emissions to air associated with the increase in transport. \ua9 2005 Published by Elsevier Ltd

Butyrate Permeation across the Isolated Ovine Reticulum Epithelium

We hypothesized that, due to the high pH of this compartment, the reticulum epithelium displays particular features in the transport of short-chain fatty acids (SCFA). Ovine reticulum epithelium was incubated in Ussing chambers using a bicarbonate-free buffer solution containing butyrate (20 mmol L−1). p-hydroxymercuribenzoic acid (pHMB), 5-(N-Ethyl-N-isopropyl)amiloride (EIPA), or ouabain were added to the buffer solution as inhibitors of monocarboxylate transporters, sodium-proton-exchangers, or the Na+/K+-ATPase, respectively. The short-circuit current (Isc) and transepithelial conductance (Gt) were monitored continuously while the flux rates of 14C-labelled butyrate were measured in the mucosal-to-serosal (Jmsbut) or serosal-to-mucosal direction (Jsmbut). Under control conditions, the mean values of Isc and Gt amounted to 2.54 ± 0.46 µEq cm−2 h−1 and 6.02 ± 3.3 mS cm−2, respectively. Jmsbut was 2.1 ± 1.01 µmol cm−2 h−1 on average and about twice as high as Jsmbut. Incubation with ouabain reduced Jmsbut, while Jsmbut was not affected. The serosal addition of EIPA did not affect Jmsbut but reduced Jsmbut by about 10%. The addition of pHMB to the mucosal or serosal solution reduced Jmsbut but had no effect on Jsmbut. Mucosally applied pHMB provoked a transient increase in the Isc. The serosal pHMB sharply reduced Isc. Our results demonstrate that butyrate can be effectively transported across the reticulum epithelium. The mechanisms involved in this absorption differ from those known from the rumen epithelium

Butyrate Protects Porcine Colon Epithelium from Hypoxia-Induced Damage on a Functional Level

The large intestinal epithelium is confronted with the necessity to adapt quickly to varying levels of oxygenation. In contrast to other tissues, it meets this requirement successfully and remains unharmed during (limited) hypoxic periods. The large intestine is also the site of bacterial fermentation producing short-chain fatty acids (SCFA). Amongst these SCFA, butyrate has been reported to ameliorate many pathological conditions. Thus, we hypothesized that butyrate protects the colonocytes from hypoxic damage. We used isolated porcine colon epithelium mounted in Ussing chambers, incubated it with or without butyrate and simulated hypoxia by changing the gassing regime to test this hypothesis. We found an increase in transepithelial conductance and a decrease in short-circuit current across the epithelia when simulating hypoxia for more than 30 min. Incubation with 50 mM butyrate significantly ameliorated these changes to the epithelial integrity. In order to characterize the protective mechanism, we compared the effects of butyrate to those of iso-butyrate and propionate. These two SCFAs exerted similar effects to butyrate. Therefore, we propose that the protective effect of butyrate on colon epithelium under hypoxia is not (only) based on its nutritive function, but rather on the intracellular signaling effects of SCFA

Development of air quality boxes based on low-cost sensor technology for ambient air quality monitoring

Analyses of the relationships between climate, air substances and health usually concentrate on urban environments because of increased urban temperatures, high levels of air pollution and the exposure of a large number of people compared to rural environments. Ongoing urbanization, demographic ageing and climate change lead to an increased vulnerability with respect to climate-related extremes and air pollution. However, systematic analyses of the specific local-scale characteristics of health-relevant atmospheric conditions and compositions in urban environments are still scarce because of the lack of high-resolution monitoring networks. In recent years, low-cost sensors (LCS) became available, which potentially provide the opportunity to monitor atmospheric conditions with a high spatial resolution and which allow monitoring directly at vulnerable people. In this study, we present the atmospheric exposure low-cost monitoring (AELCM) system for several air substances like ozone, nitrogen dioxide, carbon monoxide and particulate matter, as well as meteorological variables developed by our research group. The measurement equipment is calibrated using multiple linear regression and extensively tested based on a field evaluation approach at an urban background site using the high-quality measurement unit, the atmospheric exposure monitoring station (AEMS) for meteorology and air substances, of our research group. The field evaluation took place over a time span of 4 to 8 months. The electrochemical ozone sensors (SPEC DGS-O3: R(2): 0.71–0.95, RMSE: 3.31–7.79 ppb) and particulate matter sensors (SPS30 PM1/PM2.5: R(2): 0.96–0.97/0.90–0.94, RMSE: 0.77–1.07 µg/m(3)/1.27–1.96 µg/m(3)) showed the best performances at the urban background site, while the other sensors underperformed tremendously (SPEC DGS-NO2, SPEC DGS-CO, MQ131, MiCS-2714 and MiCS-4514). The results of our study show that meaningful local-scale measurements are possible with the former sensors deployed in an AELCM unit

The identification of critical facilities from the position of cybersecurity violation by the example of energy

The article describes methods for identification of critical facilities, being a significant trend in researching critical infrastructures, particularly in the energy sector. The proposed methods are focused on the investigation of the energy object state in relation to the violation of cybersecurity of its information infrastructure. The cyber threats are believed to be important contemporary threats to energy security in Russia. The proposed methods formed the basis of development information-analytical system used for monitoring of cybersecurity violations in energy sector

Die Progression des abdomienllen Aortenaneurysmas

In dieser kumulativen Arbeit werden grundlegende neue Erkenntnisse zu den pathophysiologischen Mechanismen des Aneurysmawachstums bis hin zur Ruptur dargestellt. Des Weiteren werden die aktuell verfuegbaren Mausmodelle kritisch hinsichtlich ihrer Aussagekraft untersucht. Neue Ansaetze zur besseren Diagnostik von ruturgefaehrdeten Aneurysmen und moegliche neue Therapiewege werden aufgezeigt

The design and building of a lifecycle-based process model for simulating environmental performance, product performance and cost in cement manufacturing

State of the art lifecycle inventory (LCI) models are typically used to relate resource use and emissions to manufacturing and use of a certain product. Corresponding software tools are generally specialised to perform normalisation of the flows to the functional unit. In some cases it is, however, desirable to make use of the LCI model for other types of environmental assessments. In this paper, an alternative modelling technique resulting in a more flexible model is investigated. We exemplify the above by designing and building a model of a cement plant. The commissioner\u27s, in this case Cementa AB\u27s, requirements on a flexible model that generates information on environmental performance, product performance and the economic cost were seen as important. The work reported here, thus, has two purposes: on the one hand, to explore the possibility of building more flexible LCI models, and on the other hand, to provide the commissioner with a model that fulfils their needs and requirements. Making use of a calculational a-causal and object-oriented modelling approach satisfied the commissioner\u27s special requirements on flexibility in terms of modularity and the types of calculations it was possible to perform. In addition, this model supports non-linear and dynamic elements for future use. The result is a model that can be used for a number of purposes, such as assessment of cement quality and environmental performance of the process using alternative fuels. It is also shown that by using the above modelling approach, flexibility and modularity can be greatly enhanced. \ua9 2003 Elsevier Science Ltd. All rights reserved