633 research outputs found

    Gekeimte Samen als Futtermittel - Analytik

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    Bis August 2005 dürfen im ökologischen Landbau, wenn eine ausschließliche Versorgung mit ökologischen Futtermitteln nicht möglich ist, im begrenzten Umfang konventionelle zugesetzt werden. Für den Zeitraum danach ist zu klären, ob eine ausreichende Nährstoff- und Eiweißversorgung über den Einsatz von Getreidekeimlingen gewährleistet werden kann. Die während des Keimprozesses bei Getreide auftretenden Veränderungen der für die Fütterung relevanten Inhaltsstoffe wurden untersucht. Die Keimung erfolgte sowohl unter optimierten Bedingungen in Feuchtekammern als auch unter praxisrelevanten Bedingungen in Schalen und im Keimautomat. Dabei zeigte sich, dass mit beginnender Keimung sprunghafte Veränderungen im Enzymstatus nachweisbar sind, während stoffliche Veränderungen später einsetzen und langsamer verlaufen. Das stärkeabbauende Enzym a-Amylase konnte als sensibler Indikator für den Keimungsfortschritt verwendet werden. Während der Keimung stiegen die Aktivitäten der stärkeabbauenden Enzyme und der Stärkegehalt wurde reduziert. Erwartungsgemäß stiegen die Zuckergehalte. Bei unverändertem Rohstickstoffgehalt kam es zu einer Abnahme des Proteinstickstoffgehaltes zu Gunsten der freien Aminosäuren. Der Rohfettgehalt stieg und es erhöhte sich der Gehalt an mehrfach ungesättigten Fettsäuren. Von den Aminosäuren erhöhte sich während der Keimung besonders der Gehalt von Lysin. Die deutlichsten Veränderungen durch die Keimung wurden bei den Vitaminen beobachtet. Von den 8 untersuchten Vitaminen A, B1, B2, B6, C, D3, E und K1 stiegen 6 deutlich an. Bemerkenswert war die Verringerung der Viskosität in Roggenkeimlingen, wodurch der Einsatz dieser Getreideart in der Fütterung interessant wird. Erwähnenswert ist, dass die Phytinsäure, die die Verdaulichkeit des Futters beeinträchtigt, während der Keimung stark abnimmt. Aus ernährungsphysiologischer Sicht treten vorteilhafte Veränderungen während der Keimung auf, die zu einer Verbesserung des Futterwertes beitragen

    Einsatz von gekeimtem Getreide als Futtermittel

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    Die EU-Verordnung 1804/1999 regelt die Einbeziehung der tierischen Erzeugung in den Geltungsbereich der Verordnung (EWG) Nr. 2092/91 über den ökologischen Landbau und die entsprechende Kennzeichnung der landwirtschaftlichen Erzeugnisse und Lebensmittel. Danach müssen im ökologischen Landbau alle Tiere nach den Grundregeln dieser Verordnung gehalten werden. Das Futter soll den ernährungsphysiologischen Bedarf der Tiere decken und aus dem ökologischen Anbau stammen. Dafür dürfen bis August 2005 im begrenzten Umfang konventionelle Futtermittel zugesetzt werden, wenn eine ausschließliche Versorgung mit Futtermitteln aus dem ökologischen Anbau nicht möglich ist. Für die Geflügelfütterung bedeutet das einen zulässigen Höchstanteil an konventionellem Futter von 20% im Jahr (max. 25% Trockenmasse am Tag). Bislang werden dafür besonders die konventionellen Komponenten Maiskleber und Kartoffeleiweiß, die als Nebenprodukte bei der Stärkegewinnung anfallen, eingesetzt. Vergleichbare ökologische Produkte sind z. Z. nicht verfügbar. Unter diesem Aspekt ist zu klären, ob eine ausreichende Nährstoff- und Eiweißversorgung über den Einsatz von 20% Getreidekeimlingen in der Futterration gewährleistet werden kann, die damit zu 100% ökologischer Herkunft ist. In einem, im Rahmen des Bundesprogramms ökologischer Landbau, geförderten Projekt werden alle nachfolgend aufgeführten Parameter analysiert. Proteine, Stärken, Nichtstärkepolysaccharide, Zucker und Fette als wertgebende Inhaltsstoffe sowie Auswuchs, Pilzbefall und Mykotoxine als dominierende Schadfaktoren in Getreide stehen dabei im Mittelpunkt des Interesses. Ziel ist es, Kriterien für die optimale Prozessführung der Keimung und eine hohe Produktqualität der Keimlinge zu sichern, um eine hochwertige Futterkomponente aus dem ökologischen Landbau für die Tierernährung bereitzustellen

    Thermal Conversion of Guanylurea Dicyanamide into Graphitic Carbon Nitride via Prototype CNx Precursors

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    Guanylurea dicyanamide, [(H2N)C(-O)NHC(NH2)2][N(CN)2], has been synthesized by ion exchange reaction in aqueous solution and structurally characterized by single-crystal X-ray diffraction (C2/c, a = 2249.0(5) pm, b = 483.9(1) pm, c = 1382.4(3) pm, β = 99.49(3)°, V = 1483.8(5) × 106 pm3, T = 130 K). The thermal behavior of the molecular salt has been studied by thermal analysis, temperature-programmed X-ray powder diffraction, FTIR spectroscopy, and mass spectrometry between room temperature and 823 K. The results were interpreted on a molecular level in terms of a sequence of thermally induced addition, cyclization, and elimination reactions. As a consequence, melamine (2,4,6-triamino-1,3,5-triazine) is formed with concomitant loss of HNCO. Further condensation of melamine yields the prototypic CNx precursor melem (2,6,10-triamino-s-heptazine, C6N7(NH2)3), which alongside varying amounts of directly formed CNxHy material transforms into layered CNxHy phases without significant integration of oxygen into the core framework owing to the evaporation of HNCO. Thus, further evidence can be added to melamine and its condensation product melem acting as “key intermediates” in the synthetic pathway toward graphitic CNxHy materials, whose exact constitution is still a point at issue. Due to the characteristic formation process and hydrogen content a close relationship with the polymer melon is evident. In particular, the thermal transformation of guanylurea dicyanamide clearly demonstrates that the formation of volatile compounds such as HNCO during thermal decomposition may render a large variety of previously not considered molecular compounds suitable CNx precursors despite the presence of oxygen in the starting material

    Indirekte Selektionmethoden auf Methioninreichtum des Samenproteins bei heimischen Leguminosen

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    While grain legumes can be regarded as highly valuable protein sources for animal nutrition, ceratin drawbacks inhibit their use as sole foodstuff for livestock. The nutrient quality is reduced by low concentrations of tryptophan and sulfur amino acids

    Disinhibitory involvement of the anterior cingulate cortex in the descending antinociceptive effect induced by electroacupuncture simulation in rats

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    The present study was conducted to clarify the role of the anterior cingulate cortex(ACCX) in acupuncture analgesia. Experiments were performed on 35 female Wistar albino rats weighing about 300 g. Single unit recordings were made from ACCXneurons with a tungsten microelectrode. Descending ACCX neurons were identified byantidromic activation from electrical shocks applied to the ventral part of the ipsilateral PAG through a concentric needle electrode. Cathodal electroacupuncture stimulation of Ho-Ku (0.1 ms in duration, 45 Hz) for 15 min was done by inserting stainless steel needles bilaterally. An anodal silver-plate electrode (30 mm x 30 mm) was placed on the center of the abdomen. Naloxone (1.0 mg/kg, i.v.) was used to test whether changes of ACCX activities were induced by the endogenous opioid system or not. Data were collected from a total of 73 ACCX neurons. Forty-seven neurons had descending projection to the PAG, and 26 had no projections to the PAG. A majority of descending ACCX neurons were inhibited by electroacupuncture stimulation. By contrast, non-projection ACCX neurons were mainly unaffected by electroacupuncture. Naloxone did not reverse acupuncture effects on the changes of ACCX neuronal activities. Acupuncture stimulation had predominantly inhibitory effects on the activities of descending ACCX neurons. Since the functional connection between ACCX and 3/21 PAG is inhibitory, electroacupuncture caused disinhibition of PAG neurons, whose activity is closely related to descending antinociception to the spinal cord. Thisdisinhibitory effect elicited by acupuncture stimulation is thought to play a significant role in acupuncture analgesia

    The neurobiology of Etruscan shrew active touch

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    The Etruscan shrew, Suncus etruscus, is not only the smallest terrestrial mammal, but also one of the fastest and most tactile hunters described to date. The shrew's skeletal muscle consists entirely of fast-twitch types and lacks slow fibres. Etruscan shrews detect, overwhelm, and kill insect prey in large numbers in darkness. The cricket prey is exquisitely mechanosensitive and fast-moving, and is as big as the shrew itself. Experiments with prey replica show that shape cues are both necessary and sufficient for evoking attacks. Shrew attacks are whisker guided by motion- and size-invariant Gestalt-like prey representations. Shrews often attack their prey prior to any signs of evasive manoeuvres. Shrews whisk at frequencies of approximately 14 Hz and can react with latencies as short as 25–30 ms to prey movement. The speed of attacks suggests that shrews identify and classify prey with a single touch. Large parts of the shrew's brain respond to vibrissal touch, which is represented in at least four cortical areas comprising collectively about a third of the cortical volume. Etruscan shrews can enter a torpid state and reduce their body temperature; we observed that cortical response latencies become two to three times longer when body temperature drops from 36°C to 24°C, suggesting that endothermy contributes to the animal's high-speed sensorimotor performance. We argue that small size, high-speed behaviour and extreme dependence on touch are not coincidental, but reflect an evolutionary strategy, in which the metabolic costs of small body size are outweighed by the advantages of being a short-range high-speed touch and kill predator

    Vocal Learning and Auditory-Vocal Feedback

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    Vocal learning is usually studied in songbirds and humans, species that can form auditory templates by listening to acoustic models and then learn to vocalize to match the template. Most other species are thought to develop vocalizations without auditory feedback. However, auditory input influences the acoustic structure of vocalizations in a broad distribution of birds and mammals. Vocalizations are dened here as sounds generated by forcing air past vibrating membranes. A vocal motor program may generate vocalizations such as crying or laughter, but auditory feedback may be required for matching precise acoustic features of vocalizations. This chapter discriminates limited vocal learning, which uses auditory input to fine-tune acoustic features of an inherited auditory template, from complex vocal learning, in which novel sounds are learned by matching a learned auditory template. Two or three songbird taxa and four or ve mammalian taxa are known for complex vocal learning. A broader range of mammals converge in the acoustic structure of vocalizations when in socially interacting groups, which qualifies as limited vocal learning. All birds and mammals tested use auditory-vocal feedback to adjust their vocalizations to compensate for the effects of noise, and many species modulate their signals as the costs and benefits of communicating vary. This chapter asks whether some auditory-vocal feedback may have provided neural substrates for the evolution of vocal learning. Progress will require more precise definitions of different forms of vocal learning, broad comparative review of their presence and absence, and behavioral and neurobiological investigations into the mechanisms underlying the skills.PostprintPeer reviewe

    CYP2C19 pharmacogenetics in advanced cancer: compromised function independent of genotype

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    CYP2C19 is a drug-metabolising enzyme involved in the metabolism of a number of chemotherapeutic agents including cyclophosphamide. Variants of the CYP2C19 gene result in a loss of function polymorphism, which affects approximately 3% of the Caucasian population. These individuals are poor metabolisers (PM) of a wide range of medications including omeprazole (OMP). In healthy subjects PM can be identified through homozygous variant genotype. However, a discordance between CYP2C19 genotype and phenotype has been reported previously in a small study of cancer patients. To investigate whether CYP2C19 activity was decreased in patients with advanced cancer, CYP2C19 genotype was determined in 33 advanced cancer patients using PCR-RFLP analysis for the two important allelic variants (*2,681G>A and *3,636G>A) and the activity of the enzyme was evaluated using the CYP2C19 probe drug OMP. The activity of the drug-metabolising enzyme CYP2C19 was severely compromised in advanced cancer patients, resulting in a PM status in 37% of the patients who had normal genotype. This is significantly (P<0.0005) higher than that would be predicted from the genotypic status of these patients. There was no evidence of a correlation between compromised CYP2C19 activity and any of the proinflammatory cytokines or acute phase response proteins studied. However, there was preliminary evidence of an association between PM status and low body mass (P=0.03). There is increasing interest in using pharmacogenetics to ‘individualise medicine', however, the results of this study indicate that in a cancer population genotyping for CYP2C19 would significantly underestimate the number of phenotypic PM of drugs, such as cyclophosphamide, which may be metabolised by this enzyme
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