Sperm "washing" techniques have been applied to treat a wide variety of sperm and semen disorders, as well as to prepare "normal" sperm for intrauterine insemination in the treatment of some female disorders. What is being "washed" in a sperm washing procedure are the various constituents of ...
remains unknown. We show that codas exhibit contextual and combinatorial structure. First, we report previously undescribed features of codas that are sensitive to the conversational context in which they occur, and systematically controlled and imitated across whales. We call these rubato and ornamentati...
Unisexual vertebrates have independently evolved in several lineages of fish, amphibians and reptiles (Dawley and Bogart, 1989; Avise, 2008), and although these vertebrate lineages are made up of all, or mostly all females, they are not necessarily asexual. Reproductive modes used by unisexual ...
Once the sperm are transferred to the female tract in spermatophores, marked changes occur in the sheath; the satellite body disappears, dense material appears between the inner margins of the radial discs, and the inner sheath differentiates into two distinct portions, both of which have a para...
Nature does have a selection process in the cervix. 大自然在宫颈管有一个选择的过程 It is selecting sperm that are well made. 选择那些很好的精♥子♥ It would be a bit like me, 这就有点像我 dressed as a sperm, trying to climb a staircase that's a kilometre high. 打扮成精...
Drosophila males heterozygous for the segregation distorter chromosome show a reduction in fecundity which is correlated with the degree of distortion of their segregation ratio. When males are made homozygous for the segregation distorter elements, their fecundity is lowered to just that extent expected...
The structure and physical properties of the zona pellucida are examined in relation to sperm penetration. The evidence suggests that sperm cannot penetrate it solely by force. A model for sperm penetration is elaborated in which the conjunctive application of thrust and a soluble enzyme leads to ...
One of the most widespread tactics used by males is a "mating plug", which prevents other males from getting into the female's reproductive tract. Mating plugs are used by spiders, bumblebees, squirrels and even some primates. But in the game of reproduction, every male must either play ...
1. Can filter out all kinds of impurities which are different from sperm to ensure the accuracy of test.2. Scatheless detection can ensure the sperm's natural motion state and monolayer sampling.3. All the data and dynamic static images of sperm examination for patients are stored wi...
Routine semen analysis provides limited information about a man’s male reproductive potential and can not always fully explain male infertility. Many male infertilities are caused by sperm DNA defects that routine semen quality analyses fail to detect.