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  • 1995-1999  (5)
  • 1935-1939
  • Linkage map  (2)
  • 67.70.+n  (1)
  • Calcium  (1)
  • Isometric contraction  (1)
Source
Material
Years
  • 1995-1999  (5)
  • 1935-1939
Year
Keywords
  • 1
    Electronic Resource
    Electronic Resource
    Effects of calcium, magnesium, potassium and boron on sperm cells isolated from pollen of Zea mays L. (1995)
    Springer
    Sexual plant reproduction 8 (1995), S. 113-122 
    Details
    ISSN: 1432-2145
    Keywords: Zea mays ; Calcium ; Cell integrity ; Cell viability ; Sperm cell
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Our previous studies showed that Brewbaker and Kwack salts, which have been widely used in pollen germination and sperm isolation, are not appropriate for the maintenance of isolated maize (Zea mays L.) sperm cells. In the present study, we have characterized the effects of each BKS component salt on the integrity of isolated sperm cells using hemacytometry. At 0.01 and 0.1 mM, there were no differences in cell number between control and any salt-treated cells except a 22% decrease with 0.1 mM MgSO4 at 48 h. At the 1 mM level, cell number decreased with time in the presence of Ca(NO3)2 and MgSO4, with loss of integrity of most cells at 48 h, while KNO3 and H3BO3 had little or no effect. Further characterization of calcium-induced reduction in cell integrity using flow cytometry showed that depletion of possible residual free calcium by addition of EGTA to the suspension medium improved cell longevity and viability. Exposure of isolated sperm cells to 1 mM calcium had no effect on cell integrity and viability in 5 h; however, only 12% of cells remained intact at 24 h. The reduction in cell integrity was hastened when cells were pretreated with the calcium ionophore A23187 prior to exposure to 1 mM calcium, with a 54% reduction in cell number at 1 h and complete cell lysis at 24 h. However, depletion of cytosolic free calcium by pretreatment of cells with the calcium ionophore followed by resuspension in the presence of EGTA resulted in rapid reduction of cell integrity as well. These results collectively suggest that maize sperm cells are sensitive to exogenous free calcium; however, a certain level of cytosolic free calcium is necessary for maintenance of integrity. Mechanisms of calcium-induced reduction in cell integrity are discussed along with possible roles of the sensitivity of sperm cells to calcium in fertilization.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00230898
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    Paper (German National Licenses)
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  • 2
    Electronic Resource
    Electronic Resource
    Markers for selection of the rice Xa21 disease resistance gene (1996)
    Springer
    Theoretical and applied genetics 93 (1996), S. 1119-1122 
    Details
    ISSN: 1432-2242
    Keywords: Rice ; Xa2 ; Disease resistance ; Linkage map ; Physical map
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Six molecular markers were mapped to a 7.4-cM region of rice chromosome 11 containing the Xa21 gene, which confers resistance to the pathogen Xanthomonas oryzae pv oryzae. Three markers, RG103, 248 and 818, co-segregated with Xa21 in a population of 1141 plants. Multiple copies of all marker loci were present within the region that was introgressed from Oryza longistaminata into O. sativa. The marker loci were cloned and primers were designed that defined sequence-tagged sites. Physical mapping of the three tightly linked central markers revealed that RG103, the marker that hybridizes to the Xa21 gene, resides on a separate DNA fragment from the other two markers.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00230134
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    Paper (German National Licenses)
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  • 3
    Electronic Resource
    Electronic Resource
    Markers for selection of the rice Xa21 disease resistance gene (1996)
    Springer
    Theoretical and applied genetics 93 (1996), S. 1119-1122 
    Details
    ISSN: 1432-2242
    Keywords: Key words Rice ; Xa21 ; Disease resistance ; Linkage map ; Physical map
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Six molecular markers were mapped to a 7.4-cM region of rice chromosome 11 containing the Xa21 gene, which confers resistance to the pathogen Xanthomonas oryzae pv oryzae. Three markers, RG103, 248 and 818, co-segregated with Xa21 in a population of 1141 plants. Multiple copies of all marker loci were present within the region that was introgressed from Oryza longistaminata into O. sativa. The marker loci were cloned and primers were designed that defined sequence-tagged sites. Physical mapping of the three tightly linked central markers revealed that RG103, the marker that hybridizes to the Xa21 gene, resides on a separate DNA fragment from the other two markers.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s001220050344
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    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Anthropometric determination of thigh volumes and thigh forces following acute training of increasing intensity in adult men (1996)
    Springer
    European journal of applied physiology 72 (1996), S. 528-536 
    Details
    ISSN: 1439-6327
    Keywords: Ultrasonics ; Isometric contraction ; Lactates ; Rate of perceived exertion ; Age
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The purpose of the present study was to investigate the influence of submaximal training of increasing intensity on the rate of fatigue and on the anthropometry of the quadriceps muscle. A group of 24 middle-aged male subjects trained three times a week for 12 weeks at incremental exercise intensities which elicited 66%–83% of the maximal heart rate reserve; 11 male subjects acted as controls. A purpose-built, isometric chair with an adjustable force transducer ensured a standard posture for each subject during a 20 s maximal voluntary contraction (MVC). The muscle plus bone mass of the thigh was calculated from a previously validated anthropometric method reinforced by measurements derived from water displacement and ultrasonics. Training-induced submaximal relationships were assessed by means of two ergometer tests of progressive intensity. Following training, the subjects' blood lactate concentrations had decreased from 5.5 (SD 1.7) to 3.9 (SD 1.4) mmol·1−1 (P 〈 0.01) at the final exercise intensities. They increased thigh volumes from 10.7 (SD 1.7) to 11.0 (SD 1.7) 1 (P 〈 0.05) and thigh forces in 47.5% (P 〈 0.05) of the measurements. Heart rates and rates of perceived exertion were reduced (P 〈 0.01) following training; for the controls, all the above parameters remained constant. These results would seem to indicate that a submaximal type of training could enable a group of middle-aged men to increase the isometric forces of the thigh muscles by almost 50% when completing a MVC test following training. This suggests that this is a more suitable, safer form of maintaining and increasing maximal thigh forces for this, and older, age groups than specific isometric training alone.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00242286
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    Paper (German National Licenses)
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  • 5
    Electronic Resource
    Electronic Resource
    The influence of electrostatic fields on films of liquid helium (1996)
    Springer
    Journal of low temperature physics 102 (1996), S. 11-19 
    Details
    ISSN: 1573-7357
    Keywords: 67.70.+n ; 68.15.+e ; 68.45.Gd ; 41.20.Cv
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract Prompted by the recent striking experimental results reported by Babkin and Hakonen that appeared to show that liquid helium-II does not wet magnesium fluoride, we have examined the effects that an inhomogeneous electrostatic field has on thin films of liquid helium at temperatures below 0.5K. Our model includes the influence of gravity, surface tension, the electric field and the van der Waals interaction between the helium and its supporting substrate. We show that, an inhomogeneous charge on the substrate can produce effects that mimic the surface profiles between wetted and non-wetted areas. The calculations also indicate that some special precautions may be necessary when studying films of liquid or solid helium on insulators.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00755106
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    Paper (German National Licenses)
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