Sentence examples for between levels of sperm from inspiring English sources

Many studies have now shown a positive association between levels of sperm competition and the length of the sperm cell (reviewed in [20]), and although there have been contradictory results in comparative analyses among mammals [19] [24], a recent study has shown a clear positive association also in this taxon [25].

It has been argued that sperm competition may also affect the shape of the sperm head [26] and evidence has been presented showing an association between levels of sperm competition and hook shape and size in the head of rodent spermatozoa [27].

Recent research on mating systems and brain size in a closely related mammal, bats, predicts a negative evolutionary relationship between levels of sperm competition as measured by relative testes mass, and the development of brain size stemming from an investment trade-off between two metabolically costly tissues [7].

A study on bats found no relationships between levels of sperm competition and sperm dimensions [ 35].

Furthermore, we have been able to reveal a direct relationship between levels of sperm competition and sperm swimming speed, a link that other studies have failed to find [ 26].

Studies by Dixson and colleagues failed to find relationships between levels of sperm competition and sperm length, or length of various sperm components, first in primates [ 23] and, subsequently, in mammals [ 24].

To investigate the relationship between level of sperm DNA damage, seminal oxidative status, and shock-wave lithotripsy (SWL) for distal ureteral stones.

Experimental studies have shown that there is a causal relationship between increased levels of sperm competition and larger relative testes mass [11], [12], and comparative analyses have shown that relative testes mass is closely associated with genetic paternity [13].

Although a high number of amino acid replacements, driven by positive selection, were observed in the N-terminal region of CatSper1, we did not find evidence of an association between ω ratios and levels of sperm competition or sperm velocity parameters.

Thus, the variation found in ungulate sexual traits (weapon length in Bro-Jørgensen [ 23] and Plard et al. [ 29] and both testes mass and sperm length in Gomendio et al. [ 30]) could ultimately be the result of different levels of sperm competition between mating tactics exhibited by males.

In contrast to the positive relationship that we found between the percentage of palmitic acid and levels of sperm competition, the percentage of stearic acid in spermatozoa was very similar in the four mouse species.