4,583 research outputs found

    Global versus regional food

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    The liberalisation of trade and capital transactions since the 1970s has strongly contributed to what today is known as globalisation. Food of all sorts, fresh as well as processed, and agricultural raw materials also became increasingly part of a worldwide division of labour and production. Especially by foreign direct investment and globally integrated networks of trade, transnational agro and food corporations emerged. Intertwined are processes of concentration in the retail sector of many countries. Today vertically integrated transnational food businesses represent a dominant market share. But regional and local food is still alive, in parts vibrant and developing, driven by quality and prominence of the producing regions. Furthermore, new paths of distribution as well as direct links between producers and consumers constitute short supply chains of food and thus relevant alternatives to globalised practices

    Differential expression of ABC transporters and their regulatory genes during lactation and dry period in bovine mammary tissue

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    ATP-binding cassette (ABC) transporters play a pivotal role in human physiology, and mutations in these genes often result in severe hereditary diseases. ABC transporters are expressed in the bovine mammary gland but their physiological role in this organ remains elusive. Based on findings in the context of human disorders we speculated that candidate ABC transporters are implicated in lipid and cholesterol transport in the mammary gland. Therefore we investigated the expression pattern of selected genes that are associated with sterol transport in lactating and nonlactating mammary glands of dairy cows. mRNA levels from mammary gland biopsies taken during lactation and in the first and second week of the dry period were analysed using quantitative PCR. Five ABC transporter genes, namely ABCA1, ABCA7, ABCG1, ABCG2 and ABCG5, their regulating genes LXRα, PPARγ, SREBP1 and the milk proteins lactoferrin and α-lactalbumin were assessed. A significantly enhanced expression in the dry period was observed for ABCA1 while a significant decrease of expression in this period was detected for ABCA7, ABCG2, SREBP1 and α-lactalbumin. ABCG1, ABCG5, LXRα, PPARγ and lactoferrin expression was not altered between lactation and dry period. These results indicate that candidate ABC transporters involved in lipid and cholesterol transport show differential mRNA expression between lactation and the dry period. This may be due to physiological changes in the mammary gland such as immigration of macrophages or the accumulation of fat due to the loss of liquid in the involuting mammary gland. The current mRNA expression analysis of transporters in the mammary gland is the prerequisite for elucidating novel molecular mechanisms underlying cholesterol and lipid transfer into mil

    Large Scale Separate Effects Tests on Hydrogen Combustion during Direct Containment Heating Events (KIT Scientific Reports ; 7663)

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    Combustion codes were applied to reproduce the experimental data from tests which investigate high pressure melt ejection (HPME) and direct containment heating (DCH) issue. The code calculations revealed shortcomings of the existing models which made an application of the code for reactor calculations unfeasible because of the required up-scaling. Combustion and heat loss models need further improvements. However, data from experiments at a single scale are not sufficient to reach this goal

    Molecular Dynamics Simulations of Dynamic Force Microscopy: Applications to the Si(111)-7x7 Surface

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    Molecular dynamics simulations have been performed to understand true atomic resolution, which has been observed on the Si(111)-7×\times7 surface by dynamic force microscopy in ultra high vacuum(UHV). Stable atomic-scale contrast is reproduced in simulations at constant mean height above a critical tip-sample separation when monitoring the interaction force between tip and sample. Missing or additional adatoms can be recognized in such scans, although they are less well resolved than native adatoms. The resonance frequency shift, as well as arbitrary scans, e.g. at constant force can be computed from a series of force-distance characteristics. By means of dynamic simulations we show how energy losses induced by interaction with an oscillating tip can be monitored and that they occur even in the non-contact range.Comment: 5 pages, 5 figures, accepted publication in Applied Surface Scienc

    Growth and magnetism of self-organized arrays of Fe(110) wires formed by deposition on kinetically grooved W(110)

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    Homoepitaxy of W(110) and Mo(110) is performed in a kinetically-limited regime to yield a nanotemplate in the form of a uniaxial array of hills and grooves aligned along the [001] direction. The topography and organization of the grooves were studied with RHEED and STM. The nanofacets, of type {210}, are tilted 18° away from (110). The lateral period could be varied from 4 to 12nm by tuning the deposition temperature. Magnetic nanowires were formed in the grooves by deposition of Fe at 150°C on such templates. Fe/W wires display an easy axis along [001] and a mean blocking temperature Tb=100KComment: Proceedings of ECOSS 2006 (Paris

    Fate of recombinant DNA and Cry1Ab protein after ingestion and dispersal of genetically modified maize in comparison to rapeseed by fallow deer ( Dama dama )

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    The fate of recombinant DNA in fallow deer (Dama dama) was investigated by feeding a diet of isogenic or genetically modified (GM) maize expressing Cry1Ab protein against the European corn borer (Ostrinia nubilalis). To study the degradability of ingested DNA, polymerase chain reaction (PCR) assays were introduced to detect fragments of the endogenous, highly abundant chloroplast-specific rubisco gene, the maize-specific zein gene and the recombinant cry1Ab gene. PCR analysis revealed that small chloroplast- and maize-specific DNA fragments were detectable in contents of rumen, abomasums, jejunum, caecum and colon and occasionally in visceral tissues. In contrast, no fragments of the recombinant cry1Ab gene were detectable in gastrointestinal (GI) contents. The Cry1Ab protein was analysed using an enzyme-linked immunosorbent assay (ELISA) and immunoblotting technique. Neither ELISA nor immunoblotting yielded positive signals of immunoactive Cry1Ab protein in GI contents and tissues of fallow deer fed with GM maize. In conclusion, after uptake of GM maize, neither cry1Ab-specific gene fragments nor Cry1Ab protein were detected in the GI tract of fallow deer, indicating complete digestion of the GM maize. Additional investigations on the germination capacity of conventional rapeseed and maize seed after ingestion by fallow deer and faecal excretion (endozoochory) were performed to draw conclusions regarding a potential spreading of germinable GM crop seed by deer. Germination tests revealed that germinable rapeseed kernels were detectable in faeces; in contrast, no intact maize seeds were found in faece

    High Temperature Phase Transitions in Two-Scalar Theories with Large NN Techniques

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    We consider a theory of a scalar one-component field ϕ\phi coupled to a scalar NN-component field χ\chi. Using large NN techiques we calculate the effective potential in the leading order in 1/N1/N. We show that this is equivalent to a resummation of an infinite subclass of graphs in perturbation theory, which involve fluctuations of the χ\chi field only. We study the temperature dependence of the expectation value of the ϕ\phi field and the resulting first and second order phase transitions.Comment: 11 pages, LaTex, includes 5 uuencoded postscript figures, OUTP-94-11
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