3,288 research outputs found

    Einsatz von Luzernetrockenblatt in der ökologischen Broilermast

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    In einem Fütterungsversuch sollte untersucht werden, wie sich eine sukzessive Steigerung der Luzerneblattanteile in Alleinfuttermischungen auf die Leistung von Masthühnern auswirkt und ob die Trocknungstemperatur des verwendeten Luzerneblatt­materials einen Einfluss auf den Futterverbrauch und die Gewichtsentwicklung der Tiere hat (Niedertemperaturtrocknung (LBnT) vs. Heißlufttrocknung (LB)). Es wurden 600 männliche Hubbard JA-757 Broiler auf 5 Fütterungsvarianten mit je 5 Wiederholungen verteilt (Kontrolle (K), LB 2, LB 3, LB 4, LBnT 5). Die Mast war in 3 Phasen unterteilt, die Anteile an Luzerneblattmehl wurden von Phase zu Phase um je 5% gesteigert (K: 0%-0%-0%; LB 2: 0%-5%-10%); LB 3: 5%-10%-15%; LB 4: 10%-15%-20%; LBnT 5: 10%-15%-20%). Die Tiere der Gruppe K erreichten das höchste Mastendgewicht. Die geringsten Gewichte zeigten die Gruppen LB 3, LB 4 und LBnT 5. Der Einsatz von Luzerneblattmehl, besonders der frühe Einsatz (5% ab Phase 1) und die Einmischung höherer Anteile (15-20%), führten zu signifikanten Leistungsdepressionen bei den wachsenden Broilern, welche vermutlich durch antinutritive Substanzen der Luzernepflanze (Saponine) ausgelöst wurden

    Characterization of Hamamatsu 64-channel TSV SiPMs

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    The Hamamatsu UV-light enhanced 64-channel SiPM array of the newest generation (S13361-3050AS-08) has been examined for the purpose of being used for the Silicon Elementary Cell Add-on (SiECA) of the EUSO-SPB balloon experiment. Characterization measurements have been performed with the newly installed Single Photon Calibration Stand at KIT (SPOCK). The results of the characterization measurements including the breakdown voltage, the gain, the PDE, the dark-count rate and the crosstalk probability of all 64 SiPM channels are presented. Additional measurements of the SiPM sensitivity to photons with wavelengths lower than 400nm show an improved PDE for small wavelengths compared to the SiPM array S12642-0808PA-50, which was also investigated for comparison. The response dynamics have been investigated for low numbers of incoming photons. Temperature dependent measurements of the gain, the PDE, the dark-count rate and the crosstalk probability have been performed for one channel of the SiPM array.Comment: Accepted for publication in Nuclear Instruments and Methods

    Synthetic antimicrobial and LPS-neutralising peptides suppress inflammatory and immune responses in skin cells and promote keratinocyte migration

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    The stagnation in the development of new antibiotics and the concomitant high increase of resistant bacteria emphasize the urgent need for new therapeutic options. Antimicrobial peptides are promising agents for the treatment of bacterial infections and recent studies indicate that Pep19-2.5, a synthetic anti-lipopolysaccharide (LPS) peptide (SALP), efficiently neutralises pathogenicity factors of Gram-negative (LPS) and Gram-positive (lipoprotein/-peptide, LP) bacteria and protects against sepsis. Here, we investigated the potential of Pep19-2.5 and the structurally related compound Pep19-4LF for their therapeutic application in bacterial skin infections. SALPs inhibited LP-induced phosphorylation of NF-κB p65 and p38 MAPK and reduced cytokine release and gene expression in primary human keratinocytes and dermal fibroblasts. In LPS-stimulated human monocyte-derived dendritic cells and Langerhans-like cells, the peptides blocked IL-6 secretion, downregulated expression of maturation markers and inhibited dendritic cell migration. Both SALPs showed a low cytotoxicity in all investigated cell types. Furthermore, SALPs markedly promoted cell migration via EGFR transactivation and ERK1/2 phosphorylation and accelerated artificial wound closure in keratinocytes. Peptide-induced keratinocyte migration was mediated by purinergic receptors and metalloproteases. In contrast, SALPs did not affect proliferation of keratinocytes. Conclusively, our data suggest a novel therapeutic target for the treatment of patients with acute and chronic skin infections

    Produktivität, Narbendichte und Vegetation einer Kurzrasenweide

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    Productivity, sward structure and floristic diversity of a continuous grazed pasture on organic permanent grassland were determined in 2015. Daily pasture growth reached less than 50 kg dry matter per hectare in May and stayed low due to unfavorable weather conditions in 2015 (cold spring, dry and hot summer). Forage quality was quite high (> 6,5 MJ NEL/kg dm) most of the grazing season. Tiller density was moderate during summer but increased after sufficient rain in late summer. Perennial ryegrass, Kentucky bluegrass and white clover were the dominant plant species and yielded more the 85 % of dry matter

    KASCADE: Astrophysical results and tests of hadronic interaction models

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    KASCADE is a multi-detector setup to get redundant information on single air shower basis. The information is used to perform multiparameter analyses to solve the threefold problem of the reconstruction of (i)the unknown primary energy, (ii) the primary mass, and (iii) to quantify the characteristics of the hadronic interactions in the air-shower development. In this talk recent results of the KASCADE data analyses are summarized concerning cosmic ray anisotropy studies, determination of flux spectra for different primary mass groups, and approaches to test hadronic interaction models. Neither large scale anisotropies nor point sources were found in the KASCADE data set. The energy spectra of the light element groups result in a knee-like bending and a steepening above the knee. The topology of the individual knee positions shows a dependency on the primary particle. Though no hadronic interaction model is fully able to describe the multi-parameter data of KASCADE consistently, the more recent models or improved versions of older models reproduce the data better than few years ago.Comment: to appear in Nucl. Phys. B (Proc. Suppl.), Proc. of the XIII ISVHECRI, Pylos 2004 - with a better quality of the figure

    Large scale cosmic-ray anisotropy with KASCADE

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    The results of an analysis of the large scale anisotropy of cosmic rays in the PeV range are presented. The Rayleigh formalism is applied to the right ascension distribution of extensive air showers measured by the KASCADE experiment.The data set contains about 10^8 extensive air showers in the energy range from 0.7 to 6 PeV. No hints for anisotropy are visible in the right ascension distributions in this energy range. This accounts for all showers as well as for subsets containing showers induced by predominantly light respectively heavy primary particles. Upper flux limits for Rayleigh amplitudes are determined to be between 10^-3 at 0.7 PeV and 10^-2 at 6 PeV primary energy.Comment: accepted by The Astrophysical Journa

    The wavefront of the radio signal emitted by cosmic ray air showers

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    Analyzing measurements of the LOPES antenna array together with corresponding CoREAS simulations for more than 300 measured events with energy above 101710^{17}\,eV and zenith angles smaller than 4545^\circ, we find that the radio wavefront of cosmic-ray air showers is of approximately hyperbolic shape. The simulations predict a slightly steeper wavefront towards East than towards West, but this asymmetry is negligible against the measurement uncertainties of LOPES. At axis distances 50\gtrsim 50\,m, the wavefront can be approximated by a simple cone. According to the simulations, the cone angle is clearly correlated with the shower maximum. Thus, we confirm earlier predictions that arrival time measurements can be used to study the longitudinal shower development, but now using a realistic wavefront. Moreover, we show that the hyperbolic wavefront is compatible with our measurement, and we present several experimental indications that the cone angle is indeed sensitive to the shower development. Consequently, the wavefront can be used to statistically study the primary composition of ultra-high energy cosmic rays. At LOPES, the experimentally achieved precision for the shower maximum is limited by measurement uncertainties to approximately 140140\,g/cm2^2. But the simulations indicate that under better conditions this method might yield an accuracy for the atmospheric depth of the shower maximum, XmaxX_\mathrm{max}, better than 3030\,g/cm2^2. This would be competitive with the established air-fluorescence and air-Cherenkov techniques, where the radio technique offers the advantage of a significantly higher duty-cycle. Finally, the hyperbolic wavefront can be used to reconstruct the shower geometry more accurately, which potentially allows a better reconstruction of all other shower parameters, too.Comment: accepted by JCA
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