Which sex is better for sperm?

Researchers at Duke University have developed a novel way to measure sperm quality in a new study that will help doctors identify the best test for sperm quality.

The researchers found that testosterone levels in men with normal sperm production were lower than those with abnormal levels, which could potentially lead to infertility.

The research was published in the journal Nature Methods.

The researchers compared the sperm levels of about 5,000 men with no detectable testosterone levels to the semen of men with high levels.

They found that men with low levels of testosterone had lower sperm production than men with higher testosterone levels.

Men with low testosterone also had lower levels of motility, which is a type of chemical that helps sperm to move through the reproductive tract.

The team also found that those with low motility had lower testosterone levels than men who had high levels of it.

“This is a very exciting finding,” said the lead author, Andrew W. Mollison, a professor of molecular biology at Duke.

“Sperm production is related to testosterone, but we don’t know what’s the most effective way to produce testosterone.”

This is the first study to use a sperm test to measure testosterone levels, and it is the largest study to examine sperm quality, Mollinson said.

He added that the new test could be used to screen for conditions that can cause infertility, such as the aging of the body or low sperm count.

“There are a lot of different ways to measure these things, and they all depend on how you measure them,” Mollisson said.

“It’s not as simple as you measure testosterone in the blood and it says, ‘You have testosterone.'”

In addition to testing for testosterone, Mullinsons team also used a variety of other biomarkers to assess sperm quality including levels of sperm motility and sperm morphology.

They also used genetic tests to analyze sperm production and motility.

Mollison and his team measured testosterone in sperm from men who were of European descent and who had normal semen quality.

They used sperm collected from the same men every other week for about a year to determine the levels of the three primary markers of sperm production: sperm motile capacity, sperm morphology and testosterone levels (both naturally and in response to a drug).

These markers of motile and sperm quality were measured by using a technique called immunoassay.

They were tested in semen from the participants and compared with semen from other men who matched the participants.

The results showed that testosterone in normal men is associated with lower sperm quality than in men who have high testosterone levels and who have lower sperm motiles.

The study also found an association between testosterone levels but not testosterone levels alone.

“When you look at the results from men with testosterone levels below the normal range, testosterone levels are associated with low sperm production,” Mollsison said.

The relationship between testosterone and sperm production was stronger in men of European ancestry than in other groups.

In addition, the researchers found a correlation between the two biomarkers of motiles and testosterone.

The higher the testosterone levels were, the lower the motile quality was.

The association was weaker in men without any testosterone levels at all.

In the future, the team plans to use the new testosterone assay to screen men with elevated testosterone levels for conditions such as high testosterone, low sperm motilia and low sperm counts, Mollsisons said.