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  • 1
    Electronic Resource
    Electronic Resource
    Kinematics of hamster sperm during penetration of the cumulus cell matrix (1988)
    New York, NY : Wiley-Blackwell
    Gamete Research 21 (1988), S. 367-383 
    Details
    ISSN: 0148-7280
    Keywords: spermatozoa ; motility ; hyperactivation ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: During capacitation, mammalian spermatozoa gain the ability to penetrate the cumulus cell matrix (CCM). The role of hyperactivated motility for this capacity is uncertain. In the present study, hamster sperm were observed during penetration and progression through the CCM, and flagellar beat patterns were quantitated by characterization of the underlying flagellar bends. Small numbers of sperm were added to cumulus masses slightly compressed on a slide (150 μm depth), and penetration was videorecorded using interference contrast optics. During penetration of the cumulus surface, sperm did not generate the large flagellar bends and asymmetric beats that are hallmarks of hyperactivation in low viscosity media. Instead, they entered slowly using high-frequency, low-amplitude sinusoidal flagellar motions. Within the CCM, sperm continued to move slowly, and they exhibited three distinct patterns of motility. The first was sinusoidal, produced by alternating, propagated bends: principal bends (PB) moved the head away from the beat midline, with the convex edge of the head leading, and reverse bends (RB) had the opposite curvature. The second pattern was asymmetric and sinusoidal: an extreme RB developed in the distal flagellum, was propagated distally, and was followed by a PB of less curvature. The third motility pattern was a hatchet-like stroke of the sperm head which resulted when an extreme, nonpropagated PB developed slowly in the proximal midpiece, and was released rapidly. In this mode there were no reverse bends, and sperm did not progress. There were subpopulations of capacitating sperm in free-swimming medium which had these same bend types and motility patterns, suggesting that qualitative flagellar movement may not change during CCM penetration. Sperm velocity in the CCM was not strongly correlated with flagellar beat kinematics, suggesting local heterogeneity in cumulus mechanical resistance and/or differences in interaction of the matrix with the surfaces of individual sperm. An effective viscosity of the cumulus near its border was estimated to be of the order of 1-4 P.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1120210406
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  • 2
    Electronic Resource
    Electronic Resource
    The motility of rabbit spermatozoa recovered from the female reproductive tract (1979)
    New York, NY : Wiley-Blackwell
    Gamete Research 2 (1979), S. 35-42 
    Details
    ISSN: 0148-7280
    Keywords: activated motility ; temperature dependence of motility ; sperm transport ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The motility of rabbit spermatozoa recovered from the vagina, endocervix, uterus, and four regions of the oviduct was assessed visually by phase-contrast microscopy at intervals from one minute to 16 hours after a single mating. The percentage of motile cells in each sample was dependent on the temperature of recovery, ie, 23° vs 37°C, but was not influenced by the temperature of observation. Spermatozoa in the lower isthmus of the oviduct were the most temperature sensitive population to recovery at 23°C. When all manipulations and observations were performed at 37°C, the percentage of spermatozoa with progressive motility varied according to the region sampled and interval after mating. Populations from the vagina, uterus and upper regions of the oviduct usually had a high proportion of progressively motile cells with vigorous flagellar activity. Fewer spermatozoa showed progressive movement on recovery from the endocervix and lower 2 cm of the tubal isthmus and their flagellar activity was generally depressed. The decrease in flagellar beat frequency noted in the latter regions may be a major factor limiting sperm ascent in the female tract. A unique pattern of “activated” motility was seen exclusively in populations taken from the oviducts at 6 to 16 hours after mating. This motility pattern, consisting of alternating episodes of linear progressive and vigorous nonprogressive movement, may be analogous to the activated motility described for capacitated rodent spermatozoa.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1120020105
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  • 3
    Electronic Resource
    Electronic Resource
    The movement characteristics of rabbit spermatozoa before and after activation (1981)
    New York, NY : Wiley-Blackwell
    Gamete Research 4 (1981), S. 275-282 
    Details
    ISSN: 0148-7280
    Keywords: spermatozoa ; activation ; oviduct ; sperm movements ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Spermatozoa were flushed with mineral oil from the lower isthmus of the rabbit oviduct at four hours postcoitus (pc) and 11 hours pc. Videotapes were made of sperm behavior in the native isthmic fluid and after dilution of the fluid with culture medium. The tapes showed that, initially, spermatozoa in the native isthmic fluid were virtually immotile, but immediately resumed movement on contact with the culture medium. Isthmic sperm motility then evolved over a five- to 10-minute interval into the characteristic biphasic pattern of activated movement. Cine films of isthmic spermatozoa taken with a high-speed camera were analyzed to determine flagellar beat frequency, maximum flagellar curvature, and swimming velocity. Progressiveness ratios and hydrodynamic power outputs were then calculated for individual spermatozoa. Two phases of activated sperm movement, a whiplash phase and a progressive phase, were identified and characterized. The power output of activated spermatozoa increased twentyfold in comparison with the preactivated state. The power output of activated spermatozoa did not differ between the two phases of activated movement.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1120040403
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  • 4
    Electronic Resource
    Electronic Resource
    Factors influencing the penetration of human spermatozoa into cervical mucus in vitro (1984)
    New York, NY : Wiley-Blackwell
    Gamete Research 9 (1984), S. 167-174 
    Details
    ISSN: 0148-7280
    Keywords: spermatozoa ; cervical mucus ; human ; motility ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Experiments were conducted to determine some of the biological variables that may affect sperm penetration of human cervical mucus in vitro. Quantitative tests of cervical mucus penetration were carried out to determine the percentage of successful collisons (PSC) between seminal spermatozoa and the semen-mucus interface. Fifteen duplicate comparisons and 15 triplicate comparisons of PSC values were made, each using individual samples of semen and mucus. In most cases the difference between any two comparisons was less than 10%, and there was no correlation between the magnitude of the difference between tests and the absolute value of the PSC. The triplicate comparison showed no correlation between the PSC values and the location of the mucus in the collection catheter (proximal, middle, distal). In 15 experiments the semen was serially diluted with an aliquot of its own plasma to determine the effect of sperm concentration on the PSC. No effects were observed until the sperm concentration fell below 10 × 106 sperm/ml, when the PSC appeared to increase. These results indicate that the tests should be applicable to all but the most severely oligospermic semen samples.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1120090206
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  • 5
    Electronic Resource
    Electronic Resource
    The response of rhesus monkey sperm motility to cervical mucus and solid surfaces (1986)
    New York, NY : Wiley-Blackwell
    Gamete Research 13 (1986), S. 231-239 
    Details
    ISSN: 0148-7280
    Keywords: rhesus sperm ; motility ; cervical mucus ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Movement characteristics of rhesus monkey spermatozoa were analyzed using high-speed cinemicrography. In the first experiment, spermatozoa were studied at 100 frames/sec in diluted semen near a surface, and after entering ovulatory cervical mucus from a bonnet monkey. In mucus, the spermatozoa swam more slowly, with reduced flagellar beat frequencies. The beat shape was altered, and there was less lateral yawing of the sperm head. In the second experiment, spermatozoa in diluted semen were studied at 500 frames/sec in deep preparations, while swimming near a surface or when in the midplane of these preparations. Those sperm in the midplane swam faster, but with lower beat frequencies than those near the surface, and exhibited much more pronounced yawing motions. Such distinctions in sperm motion are probably hydromechanical in origin and may be significant during transport in the female.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1120130306
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  • 6
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    The propulsion by large amplitude waves of uniflagellar micro-organisms of finite length (1980)
    Cambridge University Press
    Details
    Publication Date: 1980-04-01
    Description: The fluid mechanics of self-propelling, slender uniflagellar micro-organisms is examined theoretically. The mathematical analysis of these motions is based upon the Stokes equations, and the body is represented by a continuous distribution of stokeslets and doublets of undetermined strength. Since the body is self-propelling, additional constraints on the total force and moment upon it are applied. A system of singular integral and auxiliary equations, in which the propulsive velocity and viscous force per unit length are the unknowns, is derived. The vector integral equation is decomposed into near- and far-field contributions, and the solution is determined by a straightforward iterative procedure. The flagella considered are of constant radius and are restricted to planar undulations. The analysis is applied to a small amplitude wave form of infinite length, and a third-order analytic solution is obtained. By means of numerical computation, the method is extended to large amplitude wave forms of both infinite and finite length. The validity and accuracy of the solution method, the effect of local curvature, and an approximate model for an attached cell body-proper are evaluated in light of alternative theories. The solution method is systematically applied to a variety of wave-form shapes representative of actual flagella. For a sinusoidal wave form, the variations in propulsive velocity, power output and propulsive efficiency are examined as functions of the number of wavelengths on the flagellum, the amplitude and the flagellar radius. Wave forms of variable amplitude and variable wavelength are also considered. Among the significant results are the effect of the cell body on pitching, the significant differences between constant frequency and constant phase-speed undulations for variable wavelength wave forms, and comparisons with other pertinent theories. © 1980, Cambridge University Press. All rights reserved.
    Print ISSN: 0022-1120
    Electronic ISSN: 1469-7645
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Published by Cambridge University Press
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  • 7
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    On the movement of slender bodies near plane boundaries at low Reynolds number (1975)
    Cambridge University Press
    Details
    Publication Date: 1975-12-01
    Description: Normal and tangential resistance coefficients are calculated for a rigid slender body close to a planar no-slip boundary or midway between and close to two such boundaries. The important length scale is found to be the separation distance from the boundaries, and the forces per unit length acting on the slender body are approximately constant along most of its length. Owing to the presence of the walls, the ratio of the normal and tangential resistance coefficients can be greater than 2, its maximum limiting value in the infinite-fluid case. Applications to the movements of flagellated micro-organisms are discussed. © 1975, Cambridge University Press. All rights reserved.
    Print ISSN: 0022-1120
    Electronic ISSN: 1469-7645
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Published by Cambridge University Press
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  • 8
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    Optimal swimming of flagellated micro-organisms (1974)
    Cambridge University Press
    Details
    Publication Date: 1974-11-06
    Description: This paper studies flagellar undulations that propel a micro-organism at a given speed while minimizing its expenditure of hydrodynamical energy. The study is in two basic parts. The first part is a qualitative inquiry into the general nature of undulations that are hydrodynamically optimal in the instantaneous sense. The results indicate that an apparent sliding of the entire flagellum along its instantaneous axis is fundamental to such motions, although an additional deformation is necessary to compensate for the presence of the organism's head. Periodic or semi-periodic undulations are clearly suggested, and must consist of travelling waves propagated in the direction opposite to propulsion. The second part of the paper is a quantitative inquiry as to the values of parameters that optimize given periodic wave shapes in the time-average sense. The trade-off between wave amplitude and the number of wavelengths is of particular interest. Results are obtained for small amplitude sinusoidal waves and finite amplitude sawtooth waves. For the latter, a single wavelength with amplitude roughly one-sixth of the wavelength is optimal. The significance of the twitching movements of the head is investigated. The results are consistent with the qualitative study and emphasize the need to inhibit such motions. The implications of the dependence of resistive-force coefficients upon wave shape are considered, and the physical significance of rotational pitching motions is assessed. © 1974, Cambridge University Press. All rights reserved.
    Print ISSN: 0022-1120
    Electronic ISSN: 1469-7645
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
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  • 9
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    Stokes flow about a sphere attached to a slender body (1974)
    Cambridge University Press
    Details
    Publication Date: 1974-07-24
    Description: Stokes flow is analysed for a combination body, consisting of a sphere attached to a slender body, translating along its axis in an infinite and otherwise un-disturbed fluid. The cross-section of the after-body, or tail, is circular; the radius, while not necessarily constant, is small compared with the radius of the spherical head. The tail is represented by a distribution of Stokeslets of strength per unit length F(z), located and directed along its axis. The interactive effect of head-tail attachment is manifested by the presence of image singularities located within the sphere. The image system for a single tail Stokeslet must be such that the no-slip condition is satisfied on the surface of the sphere. It is shown that this system consists of a Stokeslet, a Stokes doublet (stresslet only) and a source doublet located a t the image point. The strength F(z) is obtained by applying the no-slip condition to the combination body. The solution follows the lines of traditional slender-body theory, an expansion being performed in ascending powers of the reciprocal of the logarithm of the aspect ratio. The integral force parameters and F(z) are obtained to second order. The interactive effect is assessed, and the results are discussed in the context of a sedimenting micro-organism, such as a spermatozoon. The drag on the combination body is shown to be less by around 10% than the sum of the drags on an isolated sphere and tail. This drag, for a sperm-shaped body, is divided approximately equally between head and tail. © 1974, Cambridge University Press. All rights reserved.
    Print ISSN: 0022-1120
    Electronic ISSN: 1469-7645
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Published by Cambridge University Press
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