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  • 1
    ISSN: 1432-0789
    Keywords: Available P ; Isotopic exchange kinetics ; Organic soil P ; Acid phosphatase activity ; Soil microbial biomass ; Farming systems
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Geosciences , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The effects of conventional and biological farming systems on soil P dynamics were studied by measuring some microbiological parameters after 13 years of different cropping systems. The treatments included control, biodynamic, bio-organic, and conventional plots and a mineral fertilizer treatment. The farming systems differed mainly in the form and quantity of nutrients applied and in the plant protection strategies. The results of a sequential fractionation procedure showed that irrespective of the form of P applied, neither 0.5 M NaHCO inf3 sup- nor 0.1 M NaOH-extractable organic P, but only the inorganic fractions, were affected. The residual organic P, not extracted by NaHCO3 or NaOH was increased in the biodynamic and bio-organic plots. The soil microbial biomass (ATP content) and the activity of acid phosphatase were also higher in both biologically managed systems. These results were attributed to the higher quantity of organic C and organic P applied in these systems, but also to the absence of or severe reduction in chemical plant protection. The relationship between acid soil phosphatase and residual organic P was interpreted as an indication that this fraction might be involved in short-term transformations. The measurement of the intensity, quantity, and capacity factors of available soil P using the 32P isotopic exchange kinetic method showed that P could not be the factor limiting crop yield in the biological farming systems. The kinetic parameters describing the ability of P ions to leave the soil solid phase, deduced from isotopic exchange, were significantly higher for the biodynamic treatment than for all other treatments. This result, showing a modification of chemical bonds between P ions and the soil matrix, was explained by the higher Ca and organic matter contents in this system.
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  • 2
    ISSN: 1432-0789
    Keywords: Key words Organic soil P ; Acid phosphatase activity ; Soil microbial biomass ; Organic C mineralization ; Temporal fluctuations ; Farming systems ; P turnover
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Geosciences , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract We studied microbiological processes in organic P transformations in soils cultivated with conventional and biological farming systems during the 13th and 14th year of different cropping systems. The treatments included control, biodynamic, bioorganic, and conventional plots and a mineral fertilization treatment. Different P fractions were investigated using a sequential fractionation method. Labile organic P, extracted by 0.5 M NaHCO3, was not affected by the farming systems. However, residual organic P remaining in the soil at the end of the sequential fractionation procedure showed that the biodynamic treatment, in particular, led to a modification of the composition of organic P. Labile organic P, organic P extractable in 0.1 M NaOH, and total residual P all showed temporal fluctuations. As total residual P consists of more than 70% organic P, it can be assumed that residual organic P contributed to these variations. This result indicates that chemically resistant organic P participates in short-term accumulation and mineralization processes. All biological soil parameters tested in this study showed significant temporal fluctuations, mainly attributed to differences in climatic conditions between years, but possibly also related to the growth cycle of the crop. The higher values of the biological soil parameters in the biodynamic and bioorganic treatments were explained by the greater importance of manure and the different plant protection strategies. The level of phosphatase activity and mineralization of organic C indicated a higher turnover of organic substrates, and thus of organic P, in the biodynamic and bioorganic treatments. Biological parameters were shown to be critical for assessing the significance of organic P in the soil P turnover.
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  • 3
    ISSN: 1432-1106
    Keywords: Spinal cord ; Dorsal horn interneurones ; Pain mechanisms ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Electrophysiological properties of neurones in the spinal cord dorsal horn were studied in decerebrated, immobilized spinal rats. Extracellular recordings were performed at the thoraco-lumbar junction level. Each track was systematically located by extracellular injection of pontamine sky blue. According to their responses to mechanical peripheral stimuli, cells were classified in four classes: Class 1 cells: Cells activated only by nonnoxious stimuli. They were divided into — 1A: hair movement and/or touch and 1B: hair movement and/or touch and pressure or pressure only. Class 2 cells: Cells driven by both nonnoxious and noxious stimuli, divided into — 2A: hair movement and/or touch, pressure, pinch and/or pin-prick, and 2B: pressure, pinch and/or pin-prick. Class 3 cells: Cells only activated by noxious stimuli (pinch and/or pin-prick). Class 4 cells: Cells responding to joint movement or pressure on deep tissues. Peripheral transcutaneous or sural nerve stimulation clearly showed that class 1 cells were activated only by A fiber input while 68% of classes 2 and 3 cells received A and C input. Histological examination indicated that cells driven only by noxious input were located either in the deepest part or in the marginal zone (lamina I) of the dorsal horn. Nevertheless, some lamina I cells were also driven by both nonnoxious and noxious stimuli. In addition, there is a great deal of overlap between class 1 and class 2 cells. This fact was confirmed by considering the wide distribution in the dorsal horn of cells receiving A and C input. However, spinal organization of the different classes of cells consists of a preferential distribution rather than a strict lamination. This study indicates that properties of dorsal horn interneurones in the rat have a high degree of similarity with those previously described in other species (cat and monkey).
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  • 4
    ISSN: 1432-1106
    Keywords: Pain ; Analgesia ; Midbrain ; Spinal cord ; Dorsal horn
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Midbrain stimulation in chronically implanted, awake cats in the vicinity of dorsal raphe nucleus evoked profound analgesia to peripherally applied noxious stimuli. Analgesia was not accompanied by other obvious sensory or motor deficits. The peripheral field of analgesia sometimes included the entire body and in other cases was restricted to the hindquarters. Analgesia generally outlasted brain stimulation by no more than 10 sec. Stimulation distant from dorsal raphe led to pronounced motor or emotional effects precluding an adequate test of analgesia. In anesthetized cats, effects of midbrain stimulation were studied on evoked activity in dorsal horn lamina 4 and 5 cells. Stimulation of wide regions of midbrain inhibited pain-evoked activity in most lamina 5 cells without affecting responses of most lamina 4 cells. In some lamina 5 cells, midbrain stimulation inhibited responses to noxious but not innocuous stimuli. The possible role of lamina 5 cells in nociception and the possible relationship between analgesia and lamina 5 cell inhibition are discussed.
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  • 5
    ISSN: 1471-4159
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Abstract: Biosensors sensitive for in vivo monitoring of serotonin (5-HT) in the CNS by differential normal pulse voltammetry were constructed by coating treated multi-carbon fiber electrodes (mCFEs) with Nafion (N-mCFE). In vitro sensitivities of mCFE and N-mCFE were compared in solutions ranging from 5 nM to 20 µM of uric acid (UA), 5-hydroxyindoleacetic acid (5-HIAA), and 5-HT. The mCFEs were three to seven times less sensitive for 5-HIAA or UA than for 5-HT. Nafion treatment dramatically decreased sensitivity for 5-HIAA and UA of N-mCFEs (∼103 times), whereas it remained in the nanomolar range for 5-HT. In vivo, in the dorsal horn of the lumbar spinal cord of anesthetized rats, the monoamine oxidase inhibitor clorgyline (10 mg/kg i.p.) produced a reduction (55 ± 3% at 180 min) of peak 3 of oxidation current (characteristic of 5-hydroxyindoles) monitored with mCFEs, but with N-mCFEs (in this latter case the peak was termed 3N) peak 3N increased to 135 ± 5% at 180 min. The 5-HT release-inducer p-chloroamphetamine (PCA; 6 mg/kg i.p.) induced a slight (12 ± 3% at 150 min) decrease in peak 3 measured with mCFEs, whereas with N-mCFEs PCA induced a rapid increase of peak 3N (137 ± 6% at 90 min). The xanthine oxidase inhibitor allopurinol (10 mg/kg i.p.) produced a decrease (30 ± 3% at 180 min) in peak 3 (mCFEs), but peak 3N (N-mCFEs) was not affected (106% at 180 min). After pretreatment with allopurinol, PCA also produced an increase (135 ± 6% at 90 min) in peak 3N. These in vitro and in vivo data provide evidence for a highly preferential detection of 5-HT versus 5-HIAA and UA by N-mCFEs, which could be used to follow the extracellular 5-HT concentration within very discrete structures throughout the CNS.
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  • 6
    ISSN: 1460-9568
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Numerous studies have demonstrated a dense concentration of opioid receptors in the superficial layers (laminae I-II) of the spinal cord. These receptors are located both pre- and postsynaptically at this level. The purpose of this study was to assess the distribution of opioid receptors belonging to a single (C7) dorsal root. Thus, quantitative autoradiography of γ ([3H]Tyr-d-Ala-Gly-NMe-Phe-Gly-ol; [3H]DAMGO) and δ ([3H]Tyr-d-Thr-Gly-Phe-Leu-Thr; [3H]DTLET) opioid binding sites was performed for several experimental groups: control rats with intact dorsal roots and lesioned rats with a unilateral dorsal rhizotomy of (a) the C7 root alone, (b) the three successive roots rostral and caudal to the spared C7 root, and (c) the seven roots C4-Th2. By subtracting results of the ‘C7 cut’ group from the ‘intact’ group or by subtracting results of the C4-Th2 cut group from the C7 spaced group, it was possible to measure the distribution of γ. and δ opioid binding sites belonging to the C7 root. The combination of these two methods of calculation allowed us to demonstrate a significant distribution over two segments rostral and one segment caudal to the segment of entry. For [3H]DAMGO, the distribution was 10% (P 〈 0.05) in the C5, 27%, (P 〈 0.001) in the C6, 38% (P 〈 0.001) in the C7 and 14% (P 〈 0.05) in the C8 segment. For [3H]DTLET, the distribution was 11% (P= 0.05) in the C5, 27%, (P 〈 0.01) in the C6, 37% (P 〈 0.001) in the C7 and 18% (P 〈 0.05) in the C8 segment. It is also noted that rostral distributions spread more densely and further than the caudal ones.
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  • 7
    ISSN: 1432-0789
    Keywords: Organic soil P ; Acid phosphatase activity ; Soil microbial biomass ; Organic C mineralization ; Temporal fluctuations ; Farming systems ; P turnover
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Geosciences , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract We studied microbiological processes in organic P transformations in soils cultivated with conventional and biological farming systems during the 13th and 14th year of different cropping systems. The treatments included control, biodynamic, bioorganic, and conventional plots and a mineral fertilization treatment. Different P fractions were investigated using a sequential fractionation method. Labile organic P, extracted by 0.5 M NaHCO3, was not affected by the farming systems. However, residual organic P remaining in the soil at the end of the sequential fractionation procedure showed that the biodynamic treatment, in particular, led to a modification of the composition of organic P. Labile organic P, organic P extractable in 0.1 M NaOH, and total residual P all showed temporal fluctuations. As total residual P consists of more than 70% organic P, it can be assumed that residual organic P contributed to these variations. This result indicates that chemically resistant organic P participates in short-term accumulation and mineralization processes. All biological soil parameters tested in this study showed significant temporal fluctuations, mainly attributed to differences in climatic conditions between years, but possibly also related to the growth cycle of the crop. The higher values of the biological soil parameters in the biodynamic and bioorganic treatments were explained by the greater importance of manure and the different plant protection strategies. The level of phosphatase activity and mineralization of organic C indicated a higher turnover of organic substrates, and thus of organic P, in the biodynamic and bioorganic treatments. Biological parameters were shown to be critical for assessing the significance of organic P in the soil P turnover.
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  • 8
    ISSN: 1420-908X
    Keywords: Key words: Carrageenan — c-Fos — Dorsal horn — Lornoxicam — Nociception
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract. Objective: To evaluate the anti-inflammatory/analgesic effects of lornoxicam in the carrageenan model of inflammatory nociception.¶Material and Methods: Three hours after intraplantar carrageenan (6 mg/150 μl of saline), we assessed the effects of pre-administered lornoxicam (0.1, 0.3, 1, 3 and 9 mg/kg i.v., n = 10 rats for each group) on both the peripheral oedema and number of c-Fos-protein-like immunoreactive (c-Fos-LI) neurons in the lumbar L4-L5 segments, in the awake rat.¶Results: Lornoxicam dose-relatedly reduced both the carrageenan evoked oedema (r = 0.63 and r = 0.53 for paw and ankle diameter respectively; p〈0.001 for both) and total number of spinal c-Fos-LI neurons (r = 0.79; p〈0.001), with the strongest effect corresponding to a 75 ± 2% reduction of the number of c-Fos-LI neurons (p〈0.001) for the highest dose (9 mg/kg), and a 45 ± 3% reduction (p〈0.001) for the low dose of 0.3 mg/kg. Reductions of both the peripheral oedema and spinal c-Fos expression were correlated (r = 0.74 and r = 0.57 for the paw and ankle diameter respectively; p〈0.001 for both).¶Conclusions: Our results demonstrate that lornoxicam reduces in parallel both the carrageenan-evoked oedema and spinal c-Fos expression, with clear evidence for a potent effect of low doses of lornoxicam. Correlated reductions in c-Fos expression and paw oedema suggest a predominantly peripheral site of action of lornoxicam.
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  • 9
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Review of Scientific Instruments 57 (1986), S. 106-107 
    ISSN: 1089-7623
    Source: AIP Digital Archive
    Topics: Physics , Electrical Engineering, Measurement and Control Technology
    Notes: A four-probe technique for electrical and photoelectrical measurements in a gasketed diamond anvil cell is presented. The special anvil profile and the method for the gasket preparation used in these experiments are described. Insulation and continuity of the electrical leads are shown to be satisfactory at least up to 18 GPa. As an example we report photoconductivity measurements in GaAs beyond crossover, under pressure, between direct and indirect band-gap configurations.
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  • 10
    Electronic Resource
    Electronic Resource
    [s.l.] : Macmillan Magazines Ltd.
    Nature 398 (1999), S. 681-684 
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] Ice exhibits many solid-state transformations under pressure, and also displays a variety of metastable phases. Most of the high-pressure phases of ice can be recovered at ambient pressure provided that they are first cooled below about 100 K. These ice polymorphs might exist on the ...
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