Electrical stimulation of the vagus nerves produces an excitatory
contraction response in the isolated rat stomach. This contraction
response was abolished by atropine to unmask the vagal inhibitory
response (VIR) elicited during low frequency vagal stimulation.
Babring and Gershon (1967), after working on guinea-pigs and mice,
hypothesized that both serotonin...
This paper presents a study of the resonant transfer of energy
between filters with the viewpoint of applying this technique to
communication systems.
A summary of the existing filter designs
for this application is made.
This summary shows that a requirement
common to all these filters is that the impulse...
Biliary excretion has been of considerable interest in mammals
but has not been extensively studied in fish. To understand the
significance of biliary excretion in rainbow trout (Salmo gairdneri),
two studies were conducted.
The objective of the initial study was to evaluate the ability of
rainbow trout to excrete a...
Tissue distribution studies of calcium and lead in brain tissue
of rats were increased subsequent to a single intravenous injection
of lead, 10 mg/kg, in the form of lead acetate. Time-course
studies demonstrated that brain concentrations of calcium and lead
(in terms of wet tissue weight) were found to be...
Neuromuscular physiology has been extensively investigated
in several groups of vertebrates excluding fish. To
understand the nature of neuromuscular transmission in this
group, the response of the pectoral fin abductor muscle of
black bass (Micropterus salmoides) to nerve stimulation
under the influence of an anticho1inesterase agent was
studied. Diisopropylfluorophosphate (DFP),...
Pineal hydroxyindole-0-methyltransferase (HIOMT) activity
was monitored over a 24 h period under three different photoperiods,
16L:8D, 8L: 16D, and 12 L:12D. It was observed that in all three
groups of fish HIOMT activity was high' during the dark portion of the
photoperiod in comparison to activity during the light portion....
The question of the suitability of Walsh functions or
similar bi-valued functions used as a radar electromagnetic
carrier waveform is considered. Walsh functions are
described and effective sinusoidal steady state transfer
functions are defined for transmission elements, antenna
systems, and propagation media.
The argument is made that the unit impulse...
The performance of an organism or organismic subsystem is
the result of the interaction between the performance capacity of
the system and Its environment. Environmental conditions can
stress an organism and thus affect it's performance. In this
study, three whole organism performances were examined: critical
swimming speed, fatigue time and...
Non-vascularized hearts of buffalo sculpin (Enophrys bison)
were used to investigate the cardiac toxicity of compounds that
cause methemoglobinemia. The affinity of sculpin cardiac myoglobin
for oxygen (P50 = 1.10 torr at 20 C°, pH 7.8) was lower than that of
mammals studied (P50 = .44 and .76 torr for...
Space flight results in loss of mass and function in skeletal
muscle. Data from manned flights and animal biosatellites give
evidence of possible changes in neuromuscular interactions.
Components at the neuromuscular junction are a potential site of
action for this space-induced muscle atrophy. We examined the
nicotinic acetylcholine receptor population...