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Full-Text Articles in Physiology
The Effects Of Luminance Boundaries On Color Perception, Richard E. Kronauer, Charles F. Stromeyer Iii, Alex Chaparro
The Effects Of Luminance Boundaries On Color Perception, Richard E. Kronauer, Charles F. Stromeyer Iii, Alex Chaparro
Publications
The luminance and red-green chromatic detection mechanisms respond to, respectively, the sum and difference of the long-wave (L) and middle-wave (M) zone contrast signals. The most-detectable stimulus is not a small patch of luminance drifting grating, as suggested by others, but rather a small, foveal red-green chromatic flash. Even at the smallest test size examined, 2.3' diameter, the red-green mechanism i~s more sensitive than the luminance mechanism, which has profound implication for visual physiology. When a suprathreshold luminance flash (a pedestal) occurs coincidentally with a red-green chromatic flash, detection of color is facilitated ~2-fold, regardless of spot size, as shown …
Ultrastructure Of The Coeloms Of Auricularia Larval (Holothuroidea Echinodermata): Evidence For The Presence Of An Axocoel, E. J. Balser, E. E. Ruppert, William Jaeckle
Ultrastructure Of The Coeloms Of Auricularia Larval (Holothuroidea Echinodermata): Evidence For The Presence Of An Axocoel, E. J. Balser, E. E. Ruppert, William Jaeckle
Scholarship
A hallmark feature of echinoderm larvae is the development of the left anterior coelom. This coelom, called the axohydrocoel, consists of the morphologically distinct, but undivided, left axocel and hydrocel. The axocoelic portion forms a duct that opens to the exterior via a pore on the dorsal surface of the animal. Holothuroid larvae are thought to lack an axocoel, but develop an anterior coelom, duct, and pore that are regarded as parts of the hydrocoel. New ultrastructural data, however, show that holothuroid auricularia larvae possess an axocel and hydrocel united together into an axohydrocoel. During development the anterior coelom consists …
Seasonal Relationships Between Phytoplankton Composition, Abundance, And Primary Productivity In Three Tidal Rivers Of The Lower Chesapeake Bay, Harold G. Marshall, Kneeland K. Nesius
Seasonal Relationships Between Phytoplankton Composition, Abundance, And Primary Productivity In Three Tidal Rivers Of The Lower Chesapeake Bay, Harold G. Marshall, Kneeland K. Nesius
Biological Sciences Faculty Publications
The seasonal abundance and successional patterns of phytoplankton, including autotrophic picoplankton, are compared to spring, summer, and fall primary production maxima that occurred in three tidal rivers. The tidal freshwaters were dominated by diatoms, chlorophytes, and cyanobacteria during a late spring through early fall period of maximum growth. In contrast, downstream assemblages were dominated by estuarine diatoms, dinoflagellates, and cryptomonads which developed spring pulses and a protracted summer-fall maximum. Autotrophic picoplankton produced a major summer pulse at all river stations with reduced abundance during other seasons. The mean annual productivity rates for the tidal James, Rappahannock, and York rivers were …
Microzooplankton In The Lower Chesapeake Bay, And The Tidal Elizabeth, James, And York Rivers, Gyung-Soo Park, Harold G. Marshall
Microzooplankton In The Lower Chesapeake Bay, And The Tidal Elizabeth, James, And York Rivers, Gyung-Soo Park, Harold G. Marshall
Biological Sciences Faculty Publications
Results of a one year study in the lower Chesapeake Bay and three tidal rivers indicate an abundant microzooplankton population, with a mean concentration of 4,231.1/Liter. The most abundant components are the non-loricate ciliates (2,518.2L, 59.5% of the annual total) and tintinnids (1,400.1/L 33.1%). In lesser abundance were the rotifers (191.4/L) and nauplii larvae (121.7/L). Seasonal abundance maxima were highest in summer, followed by fall, spring and winter.