9,562 research outputs found

    Code of Practice for Organic Food Processing. With contributions from Ursula Kretzschmar, Angelika Ploeger and Otto Schmid.

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    The consumers of “low input” and organic foods have specific expectations with respect to quality parameters of processed food. These may relate to the degree of processing, concern about specific additives, nutritional composition, integrity or whole food concepts, the degree of convenience, the level of energy use and transportation distances, but also to food safety. For many processors, fulfilling all of these expectations represents a tremendous challenge in understanding and implementing the standards requirements in daily practise. Therefore, it is necessary to have in this field a guidance document for processors as well as standard setting institutions and certification/inspection bodies. In the EU project on “Quality of low input food” (QLIF, No. 50635), which deals with food safety and quality issues related to food from low-input and organic food systems, it was possible to elaborate a specific code of practise for food processing as part of the Subproject 5 on processing. The starting point for this publication was a literature survey about underlying principles of organic and low-input food processing (Schmid, Beck, Kretzschmar, 2004) and a broad European-wide consultation in 2 rounds, which was also undertaken in the QLIF-project. The results of these studies showed that many companies have serious questions related to the implementation practice of the complex requirements for organic food. Some recent scandals in this sector have made clear that in several areas an improvement of the current practises are necessary, e.g. the separation practises between organic and conventional foods. The aim of this “Code of good practice for organic food processing” (COPOF) is to give companies a comprehensive introduction to the most important requirements of the organic food sector applicable for the daily practice. Additionally, the COPOF offers a number of tools that make it possible to: a) improve the production skills effectively, b) improve and maintain the quality of organic foods and c) guarantee the safety of organic products. The basic idea of this publication was that the responsible persons in companies producing and handling the products have a strongest influence on the final products characteristics themselves. Therefore, their knowledge, abilities and the structural conditions for their work are most important factors to ensure a high quality and safety of the produced food

    Concept papers outlining parameters for further development of Organic Food Processing - Crucial topics for the revision of the EU regulation 2092/91

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    Four concept papers outline parameters for the further development of organic food processing. They are based on other work already executed in the subproject 5 Processing in the QLIF-project, in particular the literature survey on “Underlying Principles in Organic and "Low-Input Food“ Processing – Literature Survey” published in 2004 by Schmid, Beck and Kretzschmar, as well as the “Approaches used in Organic/Low Input Food Processing - impact on food quality and safety” results of a Delphi survey from an expert consultation in 13 European countries.“ (Kretzschmar, Schmid, 2006). The four crucial topics highlighted in concept papers that have been chosen are summarised below: - 1rd Concept paper on the chances for a concept of “quality of origin” and on criteria and procedures for the evaluation of additives for organic food processing -2nd concept paper on environmental orientation of organic foods producing processing companies -3rd concept paper on processing methods and their labelling -4th concept paper on the improvement of separation practice by parallel processing of conventional and organic product

    Genetic and epigenetic aspects of hepatoblastoma development and treatment

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    Genetic and epigenetic aspects of hepatoblastoma development and treatment

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    Time Series Analysis and Market Microstructure Aspects on Short Time Scales

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    ARMA-GARCH and FIGARCH models with non-normal, tempered-stable innovations are applied to intraday financial time-series on high-frequency time scales. The goal is to investigate their risk forecasting performance and to observe random scaling behavior. To this end, Value-at-Risk (VaR) and Conditional VaR is predicted. In the second part limit order books based on real trading information are modeled with a statistical-learning approach in order to forecast the execution of passive limit orders

    Synthetic X-ray and radio maps for two different models of Stephan's Quintet

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    We present simulations of the compact galaxy group Stephan's Quintet (SQ) including magnetic fields, performed with the N-body/smoothed particle hydrodynamics (SPH) code \textsc{Gadget}. The simulations include radiative cooling, star formation and supernova feedback. Magnetohydrodynamics (MHD) is implemented using the standard smoothed particle magnetohydrodynamics (SPMHD) method. We adapt two different initial models for SQ based on Renaud et al. and Hwang et al., both including four galaxies (NGC 7319, NGC 7320c, NGC 7318a and NGC 7318b). Additionally, the galaxies are embedded in a magnetized, low density intergalactic medium (IGM). The ambient IGM has an initial magnetic field of 10−910^{-9} G and the four progenitor discs have initial magnetic fields of 10−9−10−710^{-9} - 10^{-7} G. We investigate the morphology, regions of star formation, temperature, X-ray emission, magnetic field structure and radio emission within the two different SQ models. In general, the enhancement and propagation of the studied gaseous properties (temperature, X-ray emission, magnetic field strength and synchrotron intensity) is more efficient for the SQ model based on Renaud et al., whose galaxies are more massive, whereas the less massive SQ model based on Hwang et al. shows generally similar effects but with smaller efficiency. We show that the large shock found in observations of SQ is most likely the result of a collision of the galaxy NGC 7318b with the IGM. This large group-wide shock is clearly visible in the X-ray emission and synchrotron intensity within the simulations of both SQ models. The order of magnitude of the observed synchrotron emission within the shock front is slightly better reproduced by the SQ model based on Renaud et al., whereas the distribution and structure of the synchrotron emission is better reproduced by the SQ model based on Hwang et al..Comment: 20 pages, 15 figures, accepted to MNRA

    Strong magnetic fields and large rotation measures in protogalaxies by supernova seeding

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    We present a model for the seeding and evolution of magnetic fields in protogalaxies. Supernova (SN) explosions during the assembly of a protogalaxy provide magnetic seed fields, which are subsequently amplified by compression, shear flows and random motions. We implement the model into the MHD version of the cosmological N-body / SPH simulation code GADGET and we couple the magnetic seeding directly to the underlying multi-phase description of star formation. We perform simulations of Milky Way-like galactic halo formation using a standard LCDM cosmology and analyse the strength and distribution of the subsequent evolving magnetic field. A dipole-shape divergence-free magnetic field is injected at a rate of 10^{-9}G / Gyr within starforming regions, given typical dimensions and magnetic field strengths in canonical SN remnants. Subsequently, the magnetic field strength increases exponentially on timescales of a few ten million years. At redshift z=0, the entire galactic halo is magnetized and the field amplitude is of the order of a few Ό\muG in the center of the halo, and 10^{-9} G at the virial radius. Additionally, we analyse the intrinsic rotation measure (RM) of the forming galactic halo over redshift. The mean halo intrinsic RM peaks between redshifts z=4 and z=2 and reaches absolute values around 1000 rad m^{-2}. While the halo virializes towards redshift z=0, the intrinsic RM values decline to a mean value below 10 rad m^{-2}. At high redshifts, the distribution of individual starforming, and thus magnetized regions is widespread. In our model for the evolution of galactic magnetic fields, the seed magnetic field amplitude and distribution is no longer a free parameter, but determined self-consistently by the star formation process occuring during the formation of cosmic structures.Comment: 13 pages, 14 figures, accepted to MNRAS after moderate revisio

    Quantifying correlations between galaxy emission lines and stellar continua

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    We analyse the correlations between continuum properties and emission line equivalent widths of star-forming and active galaxies from the Sloan Digital Sky Survey. Since upcoming large sky surveys will make broad-band observations only, including strong emission lines into theoretical modelling of spectra will be essential to estimate physical properties of photometric galaxies. We show that emission line equivalent widths can be fairly well reconstructed from the stellar continuum using local multiple linear regression in the continuum principal component analysis (PCA) space. Line reconstruction is good for star-forming galaxies and reasonable for galaxies with active nuclei. We propose a practical method to combine stellar population synthesis models with empirical modelling of emission lines. The technique will help generate more accurate model spectra and mock catalogues of galaxies to fit observations of the new surveys. More accurate modelling of emission lines is also expected to improve template-based photometric redshift estimation methods. We also show that, by combining PCA coefficients from the pure continuum and the emission lines, automatic distinction between hosts of weak active galactic nuclei (AGNs) and quiescent star-forming galaxies can be made. The classification method is based on a training set consisting of high-confidence starburst galaxies and AGNs, and allows for the similar separation of active and star-forming galaxies as the empirical curve found by Kauffmann et al. We demonstrate the use of three important machine learning algorithms in the paper: k-nearest neighbour finding, k-means clustering and support vector machines.Comment: 14 pages, 14 figures. Accepted by MNRAS on 2015 December 22. The paper's website with data and code is at http://www.vo.elte.hu/papers/2015/emissionlines
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