“Exposure to short duration gravity load changes including microgravity, as sustained in a parabolic flight statistically significantly decreases the sperm motility and vitality of human fresh sperm samples,” the team found, adding that this may have huge importance for any prolonged human settlement missions in space.
“In the future, should humans remain in space for long periods of time with exposure to different microgravity and hypergravity peaks, which could range from months to a number of years, reproduction may pose a problem to be tackled.”
The mechanism by which sperm motility was decreased remains unknown, with further study needed.
After sparing this paper a fair bit of attention I feel I’ve wasted it.
Nowhere in the paper could i find in what conditions the test samples were kept during the experiment. This is pretty basic stuff. At this stage I’d wage sloshing was the issue.
Reading this part of the methodology:
"2.2 Initial sperm analysis
After liquefaction…
[Two paragraphs later, in the same section: ] After this first analysis, the 15 sperm samples were split into two fractions. All the samples were exposed to ‘Parabolic flight’ (split 1) and to…"
Did they liquefied the samples and tested like that? Whaa?
The “After this first analysis” should not be in the “2.2 Initial sperm analysis”. It just shouldn’t!
Then I think “15 sperm samples were split into two fractions”. … “the samples were exposed to ‘Parabolic flight’ (split 1)” — splits, fractions, what a mess!! At this stage I’ve wasted enough.
The paper should be retracted, the reviewers spanked and the editor fired.