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  • 2000-2004  (1)
  • 1985-1989  (7)
  • 42.60B  (2)
  • Fermentation  (2)
  • scent marking  (2)
  • 5-enolpyruvylshikimic acid  (1)
  • 52.80  (1)
  • A69024  (1)
Datenquelle
Materialart
Erscheinungszeitraum
Jahr
Schlagwörter
  • 1
    Digitale Medien
    Digitale Medien
    Scaling and performance of CO2 lasers at supra-atmospheric pressure (1985)
    Springer
    Applied physics 37 (1985), S. 171-179 
    Details
    ISSN: 1432-0649
    Schlagwort(e): 42.55D ; 42.60B ; 58.80
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Physik
    Notizen: Abstract The performance of a compact uv photo-preionized TE laser is studied in the pressure range 1–5 bar. As the pressure is increased, the laser pulse shape is little altered, but both the peak power and the total output pulse energy increase significantly with pressure, even for constant input electrical energy. For various gas mixtures and excitation source capacitors the measurements suggest approximate output energy scaling with the product of the source charge per unit electrode area [C.m−2] and the molecular partial pressure [CO2+N2+CO]. This is explained in terms of the pressure-dependent discharge impedance. An input-energy-related discharge instability limits the optimum laser pressure to 1.5–2.5 bar, and we show that, at constant input energy, the instability boundary depends on the molecular partial pressure alone. The pre-ionization photo-electron yield varies negligibly with pressure, but the discharge tolerance to added oxygen decreases asp −3 top −4, dependent on gas mixture. Nevertheless sealed operation for 〉105 shots has been obtained with a 5% CO2∶5% CO∶3% N2∶2% H2∶85% He gas mixture at a total pressure of 5 bar.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00692081
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  • 2
    Digitale Medien
    Digitale Medien
    X-ray preionized CO2 laser (1985)
    Springer
    Applied physics 37 (1985), S. 219-221 
    Details
    ISSN: 1432-0649
    Schlagwort(e): 42.55D ; 33.80E ; 52.80 ; 42.60B
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Physik
    Notizen: Abstract A short pulse (100 ns) high-energy x-ray source has been used to preionize a transversely excited carbon dioxide gas discharge laser of 600 cm3 active volume. The maximum output power of 60 MW in a 50 ns FWHM pulse was achieved from a CO2−N2−He−CO−Xe static gas mixture at 600 Torr pressure. The energy conversion efficiency was 6%.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00692945
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  • 3
    Digitale Medien
    Digitale Medien
    Capacity for fermentation in roots and Rhizobium nodules of Pisum sativum L. (1985)
    Springer
    Planta 166 (1985), S. 264-270 
    Details
    ISSN: 1432-2048
    Schlagwort(e): Fermentation ; Nodule ; Phosphoenolpyruvate carboxylase ; Pisum (fermentation) ; Rhizobium ; Root (fermentation)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The aim of this work was to compare the capacities for fermentation and synthesis of malate from phosphoenolpyruvate in roots and Rhizobium nodules of Pisum sativum. The nodules and the cortices and apices of roots had similar activities of glycolytic enzymes and enzymes of ethanolic and lactic fermentation when expressed on a protein basis. The activity of phosphoenolpyruvate carboxylase was similar in nodules and apices, and three to four fold lower in cortices. All three tissues had very high activities of malate dehydrogenase, significant activity of NADP-malic enzyme, and no detectable activity of phosphoenolpyruvate carboxykinase. These results do not support the belief that nodules have a substantially greater capacity to convert phosphoenolpyruvate to malate than roots, or that there are major qualitative differences in the pathways of fermentation of nodules and roots.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00397358
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  • 4
    Digitale Medien
    Digitale Medien
    Volatile components of scent material from cotton-top tamarin (Saguinus o. oedipus) (1988)
    Springer
    Journal of chemical ecology 14 (1988), S. 1367-1384 
    Details
    ISSN: 1573-1561
    Schlagwort(e): Primate ; callitrichids ; Saguinus o. oedipus ; chemical communication ; scent marking ; chemical analysis ; GC-MS ; volatile composition
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract The first chemical analysis of the volatile components of scent material from the cotton-top tamarin,Saguinus o. oedipus is presented. In contrast to our previous findings in saddle-back tamarins (Saguinus fuscicollis), the chemical composition of the scent marks is quite variable. Analysis of secretion expressed manually from different areas of the scent pads of sedated animals shows individual and regional variability. Only three components (squalene, cholesterol, andp-methoxybenzaldehyde) were found in all scent mark samples analyzed. However, suprapubic secretions obtained from one sedated female contained, in addition, 12 butyrate esters as well as five acetate esters which were homologous to the butyrates. The butyrate esters have been previously identified in scent material fromSaguinus fuscicollis. The variability of the composition of the scent material is discussed in relation to the scent-marking behavior of the cotton-top tamarins. Behavioral studies tested the ability of the cotton-top tamarins to discriminate between scent marks from conspecifics and scent marks from saddle-back tamarins. The group of 12 subjects discriminated between the scent marks from both species in choice tests during which they could freely contact the scent samples. However, when scent marks were presented under a screen, so that the subjects could smell but not contact the stimuli, no discrimination was shown. Four individuals displayed more interest in the screened scent stimuli than all other subjects. When these animals were tested in a second experiment for their ability to discriminate between material from the two species on the basis of only volatile cues, it became evident that they were able to do so. These results indicate that volatile cues alone enable the tamarins to recognize scent marks from conspecifics, but that additional cues perceived during contact with the scent are important for its full attractiveness and/or informational content.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01020141
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  • 5
    Digitale Medien
    Digitale Medien
    Alcohol dehydrogenase activity in the roots of marsh plants in naturally waterlogged soils (1986)
    Springer
    Planta 168 (1986), S. 130-138 
    Details
    ISSN: 1432-2048
    Schlagwort(e): Alcohol dehydrogenase ; Fermentation ; Flooding tolerance ; Marsh plant
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The aim of this work was to discover whether oxygen tensions in the roots of marsh plants in flooded soils are high enough to allow fully acrobic metabolism. Activity of alcohol dehydrogenase (ADH), a protein synthesised in anoxic plants, was measured in roots of marsh plants growing in habitats where the availability of oxygen to the roots would be expected to differ. Roots of Carex riparia in standing water had ADH activities about 2.5 times higher than those of phosphofructokinase, and comparable to ADH activities of Poa trivialis, Urtica dioica and Ranunculus repens roots in dry soil. Removal of the oxygen supply via aerenchyma to Carex roots caused a 30-fold increase in ADH activity relative to that of phosphofructokinase. There was no change in ADH activity with depth in Carex roots in waterlogged soil, but in Filipendula ulmaria roots activity was 14 times higher below 10 cm depth than near the surface. Urtica roots in waterlogged soil had alcohol dehydrogenase activities 26 times higher than roots in dry soil, but for Poa and Ranunculus roots this figure was only 1.7 and 4.2, respectively. These results indicate that the oxygen tensions in the roots of marsh plants in waterlogged soil differ considerably among species. Ethanol was the major product of fermentation in roots of all species studied. There was no correlation between ADH activity and the rate of ethanol production under anoxia of Urtica roots. The physiological significance of high ADH activities in roots is thus unclear.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00407019
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  • 6
    Digitale Medien
    Digitale Medien
    Differential effects of dopamine receptor subtype blockade on performance of rats in a reaction-time paradigm (2000)
    Springer
    Psychopharmacology 148 (2000), S. 355-360 
    Details
    ISSN: 1432-2072
    Schlagwort(e): Key words Reaction time ; Motor impairment ; Eticlopride ; Nafadotride ; A69024 ; D1 receptor ; D2 receptor ; D3 receptor
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  Rationale: Pharmacological manipulation of the dopaminergic system with antipsychotic agents disrupts motor behavior. Although most antipsychotic drugs have high affinity for D2 receptors, they also interact with other dopamine receptor subtypes. Therefore, the role of each of these receptor subtypes on motor performance is unclear. Objective: The present study sought to investigate the relative importance of D1, D2, and D3 receptors on performance in a conditioned reaction-time task known to be extremely sensitive to dysfunction of the dopaminergic nigrostriatal pathway. Methods: Rats were trained to release a lever in response to a visual cue within a reaction-time limit to receive a reinforcer (45-mg food pellet). After the behavior of the rats had stabilized, the effects of a D1 (A69024), D2 (eticlopride), and D3 (nafadotride) receptor antagonists were assessed. Results: A-69024 had no effect on performance at any dose tested (0.3, 0.6, and 1.3 mg/kg s.c.). Nafadotride (0.1, 0.3, and 1 mg/kg s.c.) produced only a mild deficit in performance at the highest dose. This deficit was characterized by an increase in the number of delayed responses with a non-significant decrease in the number of premature responses indicative of non-specific sedative effects. In contrast, the D2 receptor antagonist eticlopride (0.005, 0.01, and 0.02 mg/kg s.c.) produced profound deficits in performance as evidenced by a dose-dependent decrease in the number of correct responses. This decrease was accompanied by an increase in the number of delayed responses and a lengthening of the reaction time at the highest doses. Conclusions: These results provide further evidence that the execution of the reaction-time task is dependent preferentially upon the activation of D2 receptors, but not D1 or D3 receptors.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s002130050063
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  • 7
    Digitale Medien
    Digitale Medien
    Expression of glyphosate resistance in carrot somatic hybrid cells through the transfer of an amplified 5-enolpyruvylshikimic acid-3-phosphate synthase gene (1988)
    Springer
    Molecular genetics and genomics 211 (1988), S. 357-363 
    Details
    ISSN: 1617-4623
    Schlagwort(e): Gen amplification ; Glyphosate resistance ; 5-enolpyruvylshikimic acid ; 3-phosphate synthase (EPSPS) ; Protoplast fusion ; Amino acid analogs
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary A Daucus carota cell line selected as resistant to N-(phosphonomethyl)-glycine (glyphosate) was found to have increased levels of 5-enolpyruvylshikimic acid-3-phosphate synthase (EPSPS) activity of 5.5 times over wild-type carrot and an EPSPS protein level increase of 8.7 times as confirmed by Western hybridization analysis. Southern blot hybridization using a petunia EPSPS probe showed increases in the number of copies of EPSPS genes in the glyphosate-resistant line which correlated with the higher levels of the EPSPS enzyme. The mechanism of resistance to glyphosate is therefore due to amplification of the EPSPS gene. To examine the stability of the amplified genes, cloned lines selected as doubly resistant to Dl-5-methyltryptophan (5MT) and azetidine-2-carboxylate (A2C) were fused with the amplified EPSPS glyphosate-resistant cell line. Somatic hybrids expressed resistances to 5MT in a semidominant fashion while A2C and glyphosate resistance was expressed as dominant, or semi-dominant traits, in a line-specific manner. The hybrid lines possessed additive chromosome numbers of the parental lines used and no double minute chromosomes were observed. The glyphosate-resistant parental line and most somatic hybrids retained the amplified levels of EPSPS in the absence of selection pressure over a 3-year period.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00330616
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  • 8
    Digitale Medien
    Digitale Medien
    Analysis of chemical signals in a primate species (Saguinus fuscicollis): Use of behavioral, chemical, and pattern recognition methods (1986)
    Springer
    Journal of chemical ecology 12 (1986), S. 513-531 
    Details
    ISSN: 1573-1561
    Schlagwort(e): Chemical communication ; scent marking ; pattern recognition ; Saguinus fuscicollis ; GC-MS ; primate ; tamarin ; skin secretions ; n-butyrate esters ; concentration profiles
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract Scent marking with specialized skin glands is a common behavior in the tamarin,Saguinus fuscicollis. The scent marks identify species, subspecies, gender, and individual, and they also contain information on the social position and hormonal condition of an animal. The marks are chemically complex, containing a large number of compounds. Analysis by means of gas chromatography-mass spectrometry has identified 16 major components (squalene and 15 esters of butyric acid). These compounds are present in the marks of males and females of two subspecies,Saguinus f. fuscicollis andSaguinus f. illigeri. Application of computerized pattern recognition techniques has shown that concentration patterns of some of the butyrates are diagnostic of the two subspecies while concentration patterns of other butyrates are diagnostic of males and females regardless of subspecies. Behavioral studies have shown that the concentration patterns of butyrates and squalene alone do not encode information on subspecies and gender. It is, however, likely that this information is partially encoded by these specific butyrate-squalene concentration patterns but that yet unidentified compounds in the scent marks serve as necessary synergists.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01020570
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