This is the 31'st update on my fly longevity experiments. In
Run #30 I have a second look at Rooibos tea, after getting a
positive result in Run# 29. I also look at red grape juice, since
in Run #14 longevity was slightly higher in flies fed grape punch,
as opposed to some other fruit juices. Finally I yet again look at
blueberry juice. Despite my high expectations, canned blueberry
juice yielded no benefit in Run #22. I decided to check the juice
from frozen blueberries this time, hoping for a hit.
Unfortunately I made a silly mistake in setting up Run #30, which
virtually destroyed the usefullness of the results. Instead of using
my regular 5 tablespoons of fluid added to 20 mg fly food, I added
6 tablespoons. The surprising consequence of this mistake was
the presence of condensation inside the milk bottles housing flies
given rooibos tea, as well (formerly frozen) blueberry juice. The
surface tension of dew drops can be deadly to flies, which drown very
easily. Since only the control, canned blueberry juice, and grape
juice bottles had no condensation, only in these bottles was a fair
test given.
Note: One of the rooibos tea bottles used tea that had been boiled
for 20 minutes, rather than just steeped. Boiling did appear to reduce
survival.
Run #30 Percent Survival on Day
supplement 4 9 14 19 23 35 41 47 53
_____________________________________________________________
control 86 81 81 71 48 10 0 - -
blueberry (canned) 94 89 78 67 56 11 6 0 -
blueberry (frozen) 63 63 31 25 25 0 - - -
grape - red 96 89 81 59 48 15 7 4 4
rooibos 0.5 bag/cup 94 58 45 19 3 3 0 - -
rooibos 1 bag/cup 94 65 61 16 6 0 - - -
rooibos 1 bag/cup (boiled) 70 45 45 20 10 0 - - -
rooibos 2 bag/cup 97 76 59 35 12 0 - - -
I also continued my cryobiology experiment, testing the effect of
pynogenol on fly freezing resistance. If pynogenol does not exert any
direct effect on freezing damage, then if it improved survival after frozen
storage, it would do so by other short term beneficial actions. These
might include suppression of freeze radical activity associated with
reperfusion damage, and inhibition of blood clotting. Before the experiment
I hypothesized that if pynogenol did not directly reduce freezing damage,
any improvement in survival it should accrue only for short storage periods,
where freezing damage is as yet not severe. With longer storage where
there is zero survival of control flies, pynogenol fed flies should also have
zero survival. This is exactly what happened.
One interesting observation was that the first census a couple of hours
after the first 90 minute period of freezer storage yielded very poor survival,
as evidenced by detection of movement. I did not expect the great increase
in survival, when a second census 3 days later was performed. Although I
had expected all the flies to be dead by then, many flies particularly in the
pynogenol 300 mg bottle had sprung miraculously back to life.
Freezer Run #3 Percent Survival After
supplement 0 90 (2'nd census) 180 minutes
___________________________________________________
control 100 0 5 0
pynogenol 300 mg 100 19 44 0
pynogenol 600 mg 96 12 15 0
This archive was generated by hypermail 2b30 : Mon May 28 2001 - 09:50:15 MDT