[From Bruce Abbott (960328.1730 EST)]
For the past three weeks now I've been running a study examining performance
on fixed ratio schedules using three female white lab rats as subjects.
However, I ordered a batch of ten and have been weighing the remaining seven
unused (thus far) rats at the same time each day. These animals have
continuous access to food and water in their home cages. They were about 90
days old when they arrived and were given a few days to recover from
shipment before weighing began. Initial handling is stressful for the rats,
but they quickly learn that no harm comes to them and adapt well to the
procedure.
Below are plotted running averages of the daily weights of these seven rats.
I've used running averages (spanning 5 days) to smooth out the variations
due to such uncontrolled variables as the female's five-day estrous cycle
and whether or not the animal had just eaten prior to weighing.
At 90 days of age these were young adults and still puting on weight
(250-300 gm is typical of fully grown females). The plots reveal that some
of the animals (96004, 96005, and 96009) have gained weight steadily and are
still gaining. One animal (96007) may have had difficulty adjusting to the
move (there was no sign of illness); she lost weight during the entire first
week of weighing but has been gaining since then. But the charts for 96006,
96008, and 96010 are the ones I find most interesting, from a weight-control
standpoint. What do you think?
Bill P., how about an interpretation?
Regards,
Bruce
···
----------------------------------------------------------------------------
96004
M - +
o --- + + +
v - -- +
i - -----------------------------+-+-+----------UCL
n 260.0+ + =
g ----------------------------+-+------------------X=258.4
- -------------+-+-+----------------------LCL
A - ------ + + + +
v ---
e 250.0+ +
r - + +
a - +
g - +
e - +
240.0+
-
-
+---------+---------+---------+---------+---------+
0 5 10 15 20 25
Sample Number
96005
M -
o - +
v - + + +
i --- +
n 275.0+ -- +
g - -------------------------------+------------UCL
- + =
A ------------------------------+-+----------------X=267.1
v - + +
e 262.5+ -----------------+------------------------LCL
r - ---- + +
a --- + +
g - + +
e - + + + +
250.0+
- +
-
+---------+---------+---------+---------+---------+
0 5 10 15 20 25
96006
M -
o - +
v 280.0+-- +
i - + +
n - --
g - ---- + +
- -----------------------------+----------UCL
A 270.0+ +
v - + + + + +=
e ----------------------+--------------------------X=266.5
r -
a - +
g 260.0+ -----------+------------------------------LCL
e - --
- +-- + +
- + + + + +
---
+---------+---------+---------+---------+---------+
0 5 10 15 20 25
Sample Number
96007
M 272.0+
o - +
v -
i ---
n - +
g 264.0+ ----
- + -------------------------------------+----UCL
A - + +
v - + =
e ----------------------------------+-+---+--------X=257.3
r 256.0+ + + + +
a - + +
g - ------------------------------------------LCL
e - -- + + +
- -- + + + +
248.0+ +
---
+---------+---------+---------+---------+---------+
0 5 10 15 20 25
Sample Number
96008
M -
o - + + + +
v 270.0+-- + +
i - -------------------+-+-------------+----------UCL
n - + + =
g ------------------+-----------------------+-+-+-+X=261.6
- ---------+--------------------------------LCL
A 255.0+ ---- +
v ---
e - +
r - +
a - +
g 240.0+ +
e -
- +
-
- +
+---------+---------+---------+---------+---------+
0 5 10 15 20 25
Sample Number
96009
M - +
o 277.5+ +
v - +
i --- +
n - -- +
g - --
270.0+ -----------------------------+-+----------UCL
A - + + =
v ------------------------------+------------------X=266.9
e - +
r - -------------+-+-+----------------------LCL
a 262.5+ ---- +
g - -- +
e --- +
- +
- + + + +
255.0+ + +
+---------+---------+---------+---------+---------+
0 5 10 15 20 25
Sample Number
96010
M -
o -
v 280.0+--
i - -- + +
n - ---------------+-----+---------------------+UCL
g - + + + + =
------------------+-----------+-+-----+-+--------X=271.2
A 270.0+ + + +
v - -----+----------------------------------LCL
e - ----
r - -- +
a ---
g 260.0+ + +
e - +
- +
- +
-
+---------+---------+---------+---------+---------+
0 5 10 15 20 25
Sample Number