Modelling the dynamics of landscape transformations and population growth in the highlands of Ethiopia using remote-sensing data

This study models landscape transformations and settlement dynamics in a highland area of Ethiopia over a 56 year period (1957–2013). The analyses were performed using aerial photographs, satellite images, and field data. The remotely sensed images were geometrically and radiometrically corrected. Visual interpretation of aerial photographs and supervised classification of multispectral satellite images using the maximum likelihood algorithm were chosen for land-cover mapping. The population size was estimated by counting the houses on the aerial photographs and on the high-resolution images, and by direct census. The overall trend showed an increase of cropland and a decrease of other types of land cover. Landscape transformation rates recently slowed down due to ownership and policy restrictions. The average cropland holding size per family has decreased from 2.6 to 1.1 ha due to the exponential growth of the population. The relationship between settlement and cropland expansion is statistically significant. Models of logistic growth were fitted to the cropland area, and models of exponential and logistic growth to the population development to estimate the carrying capacity. The concomitant increase of population and the decrease of cropland per head resulted in a shortage of food and energy, highlighting the importance of policy decisions on land management.     

Pump–Push–Probe for Ultrafast All‐Optical Switching: The Case of a Nanographene Molecule

In the last two decades, the three‐beam pump–push–probe (PPP) technique has become a well‐established tool for investigating the multidimensional configurational space of a molecule, as it permits disclosure of precious information about the multiple and often complex deactivation pathways of the excited molecule. From the spectroscopic point of view, such a tool has revealed details about the efficiency of charge pair generation and conformational relaxation in π‐conjugated molecules and macromolecules. In addition, PPP is effectively utilized for modulating the gain signal in conjugated materials by taking advantage of the spectral overlap between stimulated emission and charge absorption in those systems. However, the relatively low stability of conjugated polymers under intense photoexcitation is a crucial limitation for their real employment in plastic optical fibers (POFs) and for signal control applications. Herein, the role of PPP for achieving ultrafast all‐optical switching in π‐conjugated systems is highlighted. Furthermore, new experimental data on optical switching of a newly synthesized nanographene molecule, namely dibenzo[hi,st]ovalene (DBOV), is reported. The superior environmental and photostability of DBOV and, in general, of graphene nanostructures can represent a great advantage for their effective applications in POFs and information and communications technology.     

Semantics in space systems architectures

Costs, life cycles, technologies and agreements between stakeholders and organizations make space systems unique with respect to the complexity. A commonly accepted technique to address part of this complexity is to model and to maintain space systems architectures through the life cycle of their space programs. The benefits may range from supporting consistent model definitions and maintenance up to supporting analysis and verification. Space systems architectures have been modeled using UPDM (unified profile for DoDAF And MODAF; a UML profile). In fact, UPDM argues that it provides a clearer understanding of the semantics behind specific views and viewpoints. Nonetheless, while UML defines its semantics imprecisely using plain text and variation points, UPDM does not define any semantics. In this paper, we evaluate an extension of fUML (semantics of a foundational subset for executable UML models) as a semantics for space systems architectures. The extension of fUML as a synchronous language (synchronous fUML) provides a limited, but formally precise and deterministic, form to describe structure and behavior in UML. Through the combination of this semantics with UPDM, a precise language supporting a standardized meta-model emerges for the definition of space systems architectures. At the end, a simplified case study covering the operational view (OV-*) is presented. Our initial results show that synchronous fUML is able to offer a precise and deterministic semantics for UPDM.     

A discontinuous phase field approach to variational growth-based topology optimization

Numerical instabilities cause the well-known problem of checkerboarding during topology optimization: elements that possess material are periodically neighbored to elements that are material-free. Furthermore, such numerical solutions depend on the finite element mesh and no reasonable processing techniques exist for manufacture. Thus, integral- or gradient-based regularization techniques are usually applied during topology optimization. In this paper, a novel approach to regularization is derived for a recently published variational approach to topology optimization that is based on material growth. The presented approach shares some similarities with the discontinuous Galerkin method and completely removes consideration of additional nodal quantities or complex integration schemes. The derivation and numerical treatment of the resulting phase field equation as well as exemplary numerical results are presented.     

AMPK Prevents Palmitic Acid-Induced Apoptosis and Lipid Accumulation in Cardiomyocytes

Palmitic acid, a main fatty acid (FA) in human nutrition, can induce apoptosis of cardiomyocytes. However, a specific combination of palmitic, myristic and palmitoleic acid (CoFA) has been reported to promote beneficial cardiac growth. The aim of this study was to investigate the relevance of CoFA for cardiac growth and to delineate the underlying signaling pathways of CoFA and palmitic acid treatment. CoFA treatment of C57Bl/6 mice increased FA serum concentrations. However, morphologic and echocardiographic analysis did not show myocardial hypertrophy. Cell culture studies using rat ventricular cardiomyocytes revealed an increased phosphorylation of AMP activated protein kinase α (AMPKα) to 155 ± 19% and its target acetyl-CoA-carboxylase to 177 ± 23% by CoFA. Treatment with myristic acid also increased AMPKα phosphorylation to 189 ± 32%. Palmitic acid did not activate AMPKα but increased expression of the FA translocase CD36 (FAT/CD36) to 163 ± 23% and adipose-differentiation-related-protein (ADRP), a sensitive marker of lipid accumulation, to 168 ± 42%. This was associated with an increased phosphorylation of the stress-activated-protein-kinase/Jun-amino-terminal-kinase (SAPK/JNK) to 173 ± 27%. In CoFA-treated cells, phosphorylation of SAPK/JNK was unaltered. FACS analysis revealed increased apoptosis to 159 ± 5% by palmitic acid but not by CoFA. AMPK activator AICAR (5-aminoimidazole-4-carboxamide ribonucleotide) prevented up-regulation of ADRP and increased apoptosis by palmitic acid. Confirming these findings, inhibition of AMPK by compound C in CoFA-treated cardiomyocytes resulted in an increased expression of ADRP to 154 ± 27%, FAT/CD36 to 167 ± 28% and apoptosis to 183 ± 12%. These data reveal that AMPK activation plays an important role in prevention of palmitic acid-induced apoptosis and lipid accumulation in cardiomyocytes.     

Polychlorierte Biphenyle (PCB) in Fischen aus Teichwirtschaften und Nachkl?rteichen

Zusammenfassung Das Muskelgewebe von 58 Fischen aus Teichwirtschaften und 17 Fischen aus Nachklärteichen wurde auf seinen Gehalt an den sechs in der Schadstoff-Höchstmengenverordnung aufgeführten polychlorierten Biphenyl-(PCB)-Kongeneren sowie 2,2,4,5-Tetrachlorbiphenyl (PCB Nr. 49) untersucht. Die Tiere wurden in den Jahren 1986 und 1987 den Gewässern entnommen. Sie waren mit hoch und auch mit niedrig chlorierten Biphenylen belastet. Die Konzentrationen derniedrig chlorierten Kongeneren Nr. 28, 49 und 52 lagen deutlich unter denen der hoch chlorierten. Dennoch belegen die Ergebnisse den Eintrag von Komponenten des niedrig chlorierten technischen Gemisches Clophen C in Umwelt und Nahrungsketten. Verglichen mit den 1980/81 durchgeführten Untersuchungen an Fischen aus Teichwirtschaften war—bezogen auf das hoch chlorierte technische Gemisch Clophen A 60—ein Rückgang der PCB-Belastung des Muskelgewebes erkennbar. Dies steht mit den kürzlich von der hiesigen Arbeitsgruppe an Füchsen und Lebensmitteln erhaltenen Befunden in Übereinstimmung. Die Konzentrationen aller untersuchten PCB-Kongenere waren im Muskelgewebe von Fischen aus Nachklärteichen statistisch signifikant höher als bei den Tieren aus Teichwirtschaften. Die PCB-Gehalte sind somit vom Kontaminationsgrad der verschiedenen Lebensräume abhängig. Demnach können Fische als Bioindikator für den Eintrag hoch und niedrig chlorierter PCB-Kongenere in aquatische Ökosysteme dienen.

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Polychlorinated biphenyls in fish from fish hatcheries and settle ponds

Summary The concentrations of six selected single polychlorinated biphenyl (PCB) congeners, for which legal tolerance levels became valid in 1988, and the congener no. 49 (2,2,4,5-tetrachlorobiphenyl) were determined in the muscle tissue of 58 fishes from fish hatcheries and in 17 fishes from settle ponds. The fish were taken from flowing waters in the years 1986 and 1987. High and low chlorinated biphenyls were present in each sample, but the concentration of the low chlorinated biphenyls was distinctly lower than that of the higher chlorinated ones. Nevertheless these results demonstrate the intake of components of low chlorinated technical PCB mixtures in the environment and food chains. Compared with the investigations carried out in 1980/81 in fishes from fish hatcheries, a decrease of PCB contamination in the muscle tissues with regard to the technical mixture Clophen A 60 was observed. This is in accordance with the results our team obtained a short time previously in muscle tissue from foxes and in food-stuffs. The concentration of all PCB congeners determined in the muscle tissue from fish of settle ponds was significantly higher than in the tissue from fish taken from hatcheries. Thus, the PCB content depends on the PCB load in different environments. Therefore, fishes can be useful as bioindicators for the intake of low and high chlorinated PCB congeners in aquatic ecosystems.

     

Kontinuierliche Produktion von Sophoroselipiden mit Candida bombicola ATCC 22214

Continuous production of sophoroselipids by Candida bombicola ATCC 22214. The production of sophoroselipids with Candida hombkola from renewable carbon sources has been well investigated for some years. Nevertheless, most publications deal with batch or md batch fermentations. Up to now investigations about the continuous production are very rarely to find. Latest results show, that high productivities can be reached in continuous culture which is a serious alternative to the existing non-continuous processes. In this paper common methods producing sophoroselipids are compared to continuous production processes.     

Untersuchungen zum Kondensationsmechanismus von Copolymerisaten mit freien und verkappten Methylolamidgruppen

According to trials with model compounds the annexed methylol amide groups in N-hydroxymethyl acryl amide polymers are linked with each other by ether and methylene bridges under elimination of water and formaldehyde. The proton catalysis favours methylene cross-linking. Part of the methylol groups escape the cross-linking reaction by reforming of carbonamide groups. The purely thermal condensation of the methylol ethers occurs by elimination of alcohol and leads to a cross-linking by N-substituted methylene-bis-carbonamide groups, while in the presence of protons alkyl formal additionally develops under formation of methylene bridges.     

Energieträger aus nachwachsenden Rohstoffen

Energy from regenerable raw materials. In the long run, some of the agricultural areas in the Federal Republic of Germany will no longer be needed for food production, and could therefore be used for growing raw material plants in order to provide various sources of energy, such as wood, rape seed oil, ethanol, methanol, and biogas. With this indirect use of the solar power accumulated in the plants, the overall expenditure for fossilized fuel energy to produce these energy sources is lower than the amount of primary energy that can be substituted. Based on the assumption that 20% of farmland will be used to grow regenerable raw materials, it would be possible to replace approximately 7 million tons of coal equivalent (SKE) by wood or approximately 4 million tons of coal equivalent (SKE) by ethanol from sugar beet or methanol from wood. In the case of alcohol production from sugar beet, the total energy efficiency including the regenerative part of energy of about 74%, is lower than in the ethanol synthesis. At present, use of biomasses as an energy source is feasible only in a few rare cases, and can only be achieved if the regenerable raw materials are considered as an alternative to surplus food production or to the strategy of gradually using less acreage for growing food.     

Gewinnung von Antik?rpern gegen Sojaprotein aus Eiern immunisierter Legehennen

Zusammenfassung Die Autoren berichten über Erfahrungen mit der Immunisierung von Legehennen mit -, - und -Conglycinin aus Soja, und der Isolierung von spezifischen Antikörpern aus Eidottern. Die Aktivität und Spezifität der Immunglobuline wurde mittels Enzyme-linked immunosorbent assay (ELISA) untersucht. Besonders in Hinblick auf Einfachheit der Tierhaltung und Ausbeuten an Antikörpern bewährte sich diese Art der Antikörper-Gewinnung ausgesprochen gut. Auf die Notwendigkeit spezifischer Antiseren für die quantitative immunologische Bestimmung wird hingewiesen.

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Isolation of specific antibodies against soybean protein from the eggs of immunized laying hens

Summary The authors report on their experiences with immunization of laying hens with alpha-, alpha-and beta-conglycinin, and on the isolation of specific antibodies from the yolks. Activity and specifity of the immunoglobulins were tested by an enzyme-linked immuno sorbent assay (ELISA). This method of antibody production proved to be very convenient, especially in regard to the high yield of antibodies and the easy handling of the animals. The necessity of using specific antisera for quantitative immunoassays is pointed out.