The ultrastructure of the oviduct and the hormonal induced
alterations in the cellular organelles of prepubertal and ovariectomized
rabbits have been studied with electron-microscopic histochemical
methods.
The pseudostratified epithelium of the oviduct in prepubertal
rabbits contained both ciliated and secretory cells. The secretory
cells showed apocrine projections filled with electron-dense...
Myelin formation in the chick embryo sciatic nerve was examined
during development by analysis of three myelin lipids (cholesterol,
phospholipids, and cerebrosides) and of a myelin related
enzyme (2', 3'-cyclic AMP 3'-phosphohydrolase). The role of the
Schwann cell in controlling the synthesis of these myelin components
was studied by in...
During 1966, 1967, and 1968 extensive field investigations were
carried out in Mount Rainier National Park. These included continuous
research during the summer months, and weekend activities
during the winter months. Small mammals were trapped and
observed, and the larger mammals were observed exclusively. The
summer trapping consisted of two...
The vitamin B₁₂ concentrations in both the water and sediments
of Klamath Lake were found to vary significantly during a
one-year period. The patterns of B₁₂ distribution were remarkably
similar among the three main sites. In all cases there was an extremely
sharp gradation in concentration in relation to depth...
Spores of Equisetum were germinated and the resulting
gametophytes grown to maturity in standard microcultures. Light and
electron microscope observations were made of the chloroplasts
within the gametophytes.
These chloroplasts were found to be oval to dumb-bell shaped
organelles possessing organized grana. By means of time-lapse
movies they were shown...
Elodea densa Planch. was exposed to diquat (6, 7 dihydrodipyrido [1,2-a: 2', 1'-c] pyrazinediium dibromide), alone and in combination
with disodium endothall (disodium salt of 7-oxabicyclo [2.2.1]
heptane-2, 3-dicarboxyclic acid), and copper sulfate pentahydrate.
Studies were conducted in coastal lakes of Oregon infested with E.
densa. Dichlobenil (2, 6 dichlorobenzonitrile)...
Computer oriented techniques and procedures are presented for the analysis of single and multiple cable systems. Application is made to a two-point mooring system influenced by surface and subsurface hydrodynamic loading. The effects of the various parameters are presented and the numerical method is compared to exact solutions obtained from...
The adaptiveness of polygyny in passerines poses a particularly
intriguing problem. The altricial young of this group require extended
parental care, but young of polygynous pairings generally lack the undivided
attention of the male which young of monogamous pairings receive.
Polygynous offspring may thus be undernourished and experience
greater mortality....
The avifaunal composition of ten western Oregon forest stands located at the eastern base of the Coast Range was examined on a seasonal basis. The stands were dominated by Oregon white oak, Douglas fir or western hemlock, Avian populations were sampled monthly from January 1968 to January 1970, using permanent...