Möglichkeiten und Grenzen zur Leistungssteigerung der ökologischen Milcherzeugung am Beispiel des Lehr- und Versuchsbetriebs Gladbacherhof

Im Rahmen einer 14jährigen Fallstudie zur Steigerung der Produktionsintensität im ökologischen Landbau am Beispiel des LVB Gladbacherhof (Sommer 2010) wurde untersucht, welche Auswirkungen die Änderung des Futterregimes durch das Einsatzverbot Futtermittel konventioneller Herkunft auf die Milchleistung hatte. In diesem Beitrag soll anhand des betrieblichen Entwicklungsgeschehens aufgezeigt werden, durch welche Maßnahmen das Milchleistungsniveau in einem Zeitraum von 14 Jahren erhöht und beibehalten werden konnte. Die eingesetzten Frischmassemengen wurden in Futtertrockenmasse (TM) umgerechnet und mit den Analyseergebnissen für Nettoenergielaktation (NEL) und Rohprotein (XP) verrechnet. Die Anteile an NEL und XP aus eigenen, fremden und konventionellen Ressourcen wurden ermittelt, die NEL- und XP-Konzentrationen der eingesetzten TM berechnet und zur Jahresdurchschnittsleistung aus der Milchleistungsprüfung (MLP) ins Verhältnis gesetzt. Im Erhebungszeitraum wurde NEL-Konzentration der eingesetzten Futtertrockenmasse von 5,9 bis 7,2 MJ NEL kg TS-1 und XP-Konzentration des Futters von 156 bis 206 g kg DM XP-1 erhöht. Das Niveau der Milcherzeugung konnte von 5.750 kg bis ca. 8.000 kg pro Kuh und Jahr erhöht werden. Allerdings konnten Spitzenleistungen nur während des Einsatzes konventioneller Futtermittel realisiert werden (in Einklang mit den Vorschriften). Bei 100%iger Bio-Fütterung konnten die Spitzenleistungen nicht aufrechterhalten werden. Durch den Einsatz energiereicher (Silomais) und proteinreicher (Körnerleguminosen, legumes Feldfutter) Futtermittel konnte das Niveau jedoch auf ca. 7.500 kg pro Kuh und Jahr gehalten werden. Aufgrund der Beziehung zwischen der Milchleistung und der Energie- und Proteinkonzentration der Futtertrockenmasse wird der Schluss gezogen, dass die Produktion von hohen Milchleistungen unter den Bedingungen des ökologischen Landbaus eine Herausforderung darstellt. Hier besteht weiterer Forschungsbedarf, die 100-Prozent-Bio-Fütterung an die Erfordernisse der Milchviehernährung anzupassen

Steigerung der Produktionsintensität im Ökologischen Landbau: Ergebnisse einer 14jährigen Fallstudie am Beispiel des Lehr- und Versuchsbetriebes Gladbacherhof

Anpassungs- und Spezialisierungsdruck auf die ökologisch wirtschaftenden Betriebe steigen durch die wachsende Dominanz des Lebensmitteleinzelhandels, eine steigende Anonymität der Erzeuger sowie einen immer stärker werdenden Wettbewerb durch Globalisierung. Sinkende Erlöse und wachsender Kostendruck zwingen den einzelnen Betrieb, die Produktionsintensität zu steigern, um im Wettbewerb besser bestehen zu kön¬nen. Alternative Entwicklungsstrategien können darin liegen, betriebliche Ressourcen zu optimieren (z.B. rationellerer Futtereinsatz), zu expandieren (z.B. Betriebsvergrößerung) und/oder die Produktivität zu steigern (z.B. Erhöhung der Milchleistung je Kuh). Anhand der Entwicklung des Lehr- und Versuchsbetriebes der Justus-Liebig-Universität Gießen, Gladbacherhof, im Zeitraum von 1993 bis 2006 wird die Zunahme der Produktions¬intensität beispielhaft analysiert, dargestellt und bewertet. Besonderer Ausdruck für die Inten¬sitätssteigerung im Untersuchungszeitraum ist die gezielte Erhöhung des Rinderbesatzes auf ca. 1 GV/ha LF, verbunden mit einer Steigerung der Jahresmilchleistung auf annähernd 8.000 kg/Kuh. Eine derartige Entwicklung birgt jedoch die Gefahr einer Überforderung des Be¬triebssystems mit negativen Folgen für die Nachhaltigkeit und Umweltverträglichkeit der Produktion in sich. Es galt daher, unter Nutzung des Betriebsbilanzie¬rungsmodells REPRO und betrieblicher Daten der Mengenbuchhaltung, die Entwicklung des Betriebes für den o.g. Untersuchungszeitraum abzubilden, um daraus Schlussfolgerungen für dessen weitere Entwicklung abzuleiten. Als Folge der Entwicklung der Milchviehherde erhöhte sich die Produktion wirtschaftseigener Dünger und damit einhergehend die Düngermenge auf der landwirtschaftlichen Fläche. Allerdings blieb der außenwirtschaftliche Ertrag auf einem mehr oder weniger konstanten Niveau erhalten und konnte offensichtlich trotz zusätzlich zur Verfügung gestellter Nährstoffe nicht gesteigert werden. Die Ergebnisse der Fallstudie legen nahe, dass die Höhe der Ernteerträge im ökologischen Landbau nicht unbedingt durch die Höhe der zur Verfügung stehenden Nährstoffe begrenzt sein muss, sondern dass ihre Verfügbarkeit für den Pflanzenbestand eher die Herausforderung im betrieblichen Management darstellt und daher zukünftig stärker erforscht werden muss

Production, partitioning and stoichiometry of organic matter under variable nutrient supply during mesocosm experiments in the tropical Pacific and Atlantic Ocean

Oxygen-deficient waters in the ocean, generally referred to as oxygen minimum zones (OMZ), are expected to expand as a consequence of global climate change. Poor oxygenation is promoting microbial loss of inorganic nitrogen (N) and increasing release of sediment-bound phosphate (P) into the water column. These intermediate water masses, nutrient-loaded but with an N deficit relative to the canonical N:P Redfield ratio of 16:1, are transported via coastal upwelling into the euphotic zone. To test the impact of nutrient supply and nutrient stoichiometry on production, partitioning and elemental composition of dissolved (DOC, DON, DOP) and particulate (POC, PON, POP) organic matter, three nutrient enrichment experiments were conducted with natural microbial communities in shipboard mesocosms, during research cruises in the tropical waters of the southeast Pacific and the northeast Atlantic. Maximum accumulation of POC and PON was observed under high N supply conditions, indicating that primary production was controlled by N availability. The stoichiometry of microbial biomass was unaffected by nutrient N:P supply during exponential growth under nutrient saturation, while it was highly variable under conditions of nutrient limitation and closely correlated to the N:P supply ratio, although PON:POP of accumulated biomass generally exceeded the supply ratio. Microbial N:P composition was constrained by a general lower limit of 5:1. Channelling of assimilated P into DOP appears to be the mechanism responsible for the consistent offset of cellular stoichiometry relative to inorganic nutrient supply and nutrient drawdown, as DOP build-up was observed to intensify under decreasing N:P supply. Low nutrient N:P conditions in coastal upwelling areas overlying O2-deficient waters seem to represent a net source for DOP, which may stimulate growth of diazotrophic phytoplankton. These results demonstrate that microbial nutrient assimilation and partitioning of organic matter between the particulate and the dissolved phase are controlled by the N:P ratio of upwelled nutrients, implying substantial consequences for nutrient cycling and organic matter pools in the course of decreasing nutrient N:P stoichiometry

Multipitched plasmonic nanoparticle grating for broadband light enhancement in white light‑emitting organic diodes

We apply regular arrays of plasmonic nanodisks to enhance light emission from an organic white light-emitting diode (WOLED). To achieve broadband enhancement, we apply, first, aluminum as a nanodisk material with moderate loss throughout the whole visible spectral range. Second, broadband light coupling is mediated by surface lattice resonances from a multipitch array built from two superimposed gratings with different grating constants formed by elliptic and circular nanodisks. To demonstrate the viability of this concept, the grating structure was embedded in the hole transport layer of a solution-processed phosphorescent WOLED exhibiting a current efficiency of 2.1 cd/A at 1000 cd/m2. The surface lattice resonances in the grating raise the current efficiency of the device by 23% to 2.6 cd/A at 1000 cd/m2, while the device emission changes from a neutral white to a warm white appearance with CIE1931 (x,y) coordinates of (0.361, 0.352) and (0.404, 0.351), respectively. The WOLED was characterized in detail optically by extinction and angle-resolved photoluminescence and as well by electroluminescence measurements for its opto-electronic characteristics. The experimental results agree well with finite-difference time domain simulations that aim at a better understanding of the underlying physical mechanisms. In summary, our work presents a novel versatile approach for achieving broadband enhancement of light emission in WOLEDs over a wide spectral range.Peer Reviewe

ARC-TEC : acquisition, representation and compilation of technical knowledge

A global description of an expert system shell for the domain of mechanical engineering is presented. The ARC-TEC project constitutes an AI approach to realize the CIM idea. Along with conceptual solutions, it provides a continuous sequence of software tools for the acquisition, representation and compilation of technical knowledge. The shell combines the KADS knowledge-acquisition methodology, the KL-ONE representation theory and the WAM compilation technology. For its evaluation a prototypical expert system for production planning is developed. A central part of the system is a knowledge base formalizing the relevant aspects of common sense in mechanical engineering. Thus, ARC-TEC is less general than the CYC project but broader than specific expert systems for planning or diagnosis

Broadband UBVRI Photometry of Horizontal-Branch and Metal-Poor Candidates from the HK and Hamburg/ESO Surveys. I

We report broadband UBV and/or BVRI CCD photometry for a total of 1857 stars in the thick-disk and halo populations of the Galaxy. The majority of our targets were selected as candidate field horizontal-branch or other A-type stars (FHB/A, N = 576), or candidate low-metallicity stars (N = 1221), from the HK and Hamburg/ESO objective-prism surveys. Similar data for a small number of additional stars from other samples are also reported. These data are being used for several purposes. In the case of the FHB/A candidates they are used to accurately separate the lower-gravity FHB stars from various higher-gravity A-type stars, a subsample that includes the so-called Blue Metal Poor stars, halo and thick-disk blue stragglers, main-sequence A-type dwarfs, and Am and Ap stars. These data are also being used to derive photometric distance estimates to high-velocity hydrogen clouds in the Galaxy and for improved measurements of the mass of the Galaxy. Photometric data for the metal-poor candidates are being used to refine estimates of stellar metallicity for objects with available medium-resolution spectroscopy, to obtain distance estimates for kinematic analyses, and to establish initial estimates of effective temperature for analysis of high-resolution spectroscopy of the stars for which this information now exists.Comment: 22 pages, including 3 figures, 5 tables, and two ascii files of full data, accepted for publication in the Astrophysical Journal (Supplements

Quantitative susceptibility mapping (QSM) as a means to measure brain iron? A post mortem validation study

AbstractQuantitative susceptibility mapping (QSM) is a novel technique which allows determining the bulk magnetic susceptibility distribution of tissue in vivo from gradient echo magnetic resonance phase images. It is commonly assumed that paramagnetic iron is the predominant source of susceptibility variations in gray matter as many studies have reported a reasonable correlation of magnetic susceptibility with brain iron concentrations in vivo. Instead of performing direct comparisons, however, all these studies used the putative iron concentrations reported in the hallmark study by Hallgren and Sourander (1958) for their analysis. Consequently, the extent to which QSM can serve to reliably assess brain iron levels is not yet fully clear. To provide such information we investigated the relation between bulk tissue magnetic susceptibility and brain iron concentration in unfixed (in situ) post mortem brains of 13 subjects using MRI and inductively coupled plasma mass spectrometry. A strong linear correlation between chemically determined iron concentration and bulk magnetic susceptibility was found in gray matter structures (r=0.84, p<0.001), whereas the correlation coefficient was much lower in white matter (r=0.27, p<0.001). The slope of the overall linear correlation was consistent with theoretical considerations of the magnetism of ferritin supporting that most of the iron in the brain is bound to ferritin proteins. In conclusion, iron is the dominant source of magnetic susceptibility in deep gray matter and can be assessed with QSM. In white matter regions the estimation of iron concentrations by QSM is less accurate and more complex because the counteracting contribution from diamagnetic myelinated neuronal fibers confounds the interpretation

Broadband UBVR_CI_C Photometry of Horizontal-Branch and Metal-poor Candidates from the HK and Hamburg/ESO Surveys. I.

We report broadband UBV and/or BVR_CI_C CCD photometry for a total of 1857 stars in the thick-disk and halo populations of the Galaxy. The majority of our targets were selected as candidate field horizontal-branch or other A-type stars (FHB/A, N = 576), or candidate low-metallicity stars (N = 1221), from the HK and Hamburg/ESO objective-prism surveys. Similar data for a small number of additional stars from other samples are also reported. These data are being used for several purposes. In the case of the FHB/A candidates they are used to accurately separate the lower gravity FHB stars from various higher gravity A-type stars, a subsample that includes the so-called blue metal poor stars, halo and thick-disk blue stragglers, main-sequence A-type dwarfs, and Am and Ap stars. These data are also being used to derive photometric distance estimates to high-velocity hydrogen clouds in the Galaxy and for improved measurements of the mass of the Galaxy. Photometric data for the metal-poor candidates are being used to refine estimates of stellar metallicity for objects with available medium-resolution spectroscopy, to obtain distance estimates for kinematic analyses, and to establish initial estimates of effective temperature for analysis of high-resolution spectroscopy of the stars for which this information now exists

Initiated Chemical Vapor Deposition (iCVD) Functionalized Polylactic Acid-Marine Algae Composite Patch for Bone Tissue Engineering

The current study aimed to describe the fabrication of a composite patch by incorporating marine algae powders (MAPs) into poly-lactic acid (PLA) for bone tissue engineering. The prepared composite patch was functionalized with the co-polymer, poly (2-hydroxyethyl methacrylate-co-ethylene glycol dimethacrylate) (p(HEMA-co-EGDMA)) via initiated chemical vapor deposition (iCVD) to improve its wettability and overall biocompatibility. The iCVD functionalized MAP-PLA composite patch showed superior cell interaction of human osteoblasts. Following the surface functionalization by p(HEMA-co-EGDMA) via the iCVD technique, a highly hydrophilic patch was achieved without tailoring any morphological and structural properties. Moreover, the iCVD modified composite patch exhibited ideal cell adhesion for human osteoblasts, thus making the proposed patch suitable for potential biomedical applications including bone tissue engineering, especially in the fields of dentistry and orthopedy