The contribution of estuary-resident life histories to the return of adult Oncorhynchus kisutch.

This study evaluated estuarine habitat use, life-history composition, growth and survival of four successive broods of coho salmon Oncoryhnchus kisutch in Salmon River, Oregon, U.S.A. Subyearling and yearling O. kisutch used restored and natural estuarine wetlands, particularly in the spring and winter. Stream-reared yearling smolts spent an average of 2 weeks in the estuary growing rapidly before entering the ocean. Emergent fry also entered the estuary in the spring, and some resided in a tidal marsh throughout the summer, even as salinities increased to >20. A significant portion of the summer stream-resident population of juvenile O. kisutch migrated out of the catchment in the autumn and winter and used estuary wetlands and adjacent streams as alternative winter-rearing habitats until the spring when they entered the ocean as yearling smolts. Passive integrated transponder (PIT) tag returns and juvenile life-history reconstructions from otoliths of returning adults revealed that four juvenile life-history types contributed to the adult population. Estuarine-associated life-history strategies accounted for 20-35% of the adults returning to spawn in the four brood years, indicating that a sizable proportion of the total O. kisutch production is ignored by conventional estimates based on stream habitat capacity. Juvenile O. kisutch responses to the reconnection of previously unavailable estuarine habitats have led to greater life-history diversity in the population and reflect greater phenotypic plasticity of the species in the U.S. Pacific Northwest than previously recognized.

Alveolar consolidation detection: advanced multiple beam equalization radiography versus conventional chest radiography.

Advanced multiple beam equalization radiography (AMBER) and conventional chest radiography were prospectively evaluated in the detection and quantitation of alveolar (air-space) consolidation. Thirty-seven healthy volunteers underwent bronchoalveolar lavage (BAL), the retained lavage fluid serving as a model for alveolar consolidation. After BAL, the subjects underwent AMBER and conventional chest radiography. The lower lung zones on the radiographs were divided into four zones and graded for alveolar consolidation by three observers. There was no significant difference in the area under the receiver operating characteristic curve between the two techniques in the detection of lavage fluid. The grade of opacification was rated significantly higher (P < .05) on conventional radiographs for three of the four lung zones examined, and the correlation between the quantity of retained lavage fluid and grade of opacity was better on conventional radiographs. Detection of lavage fluid was poor with either technique. The exposure compensation of AMBER was evident in this model of air-space disease but did not affect overall observer performance.

Regional distribution of emphysema: correlation of high-resolution CT with pulmonary function tests in unselected smokers.

High-resolution computed tomography (CT) was correlated with pulmonary function tests in the evaluation of regional emphysema in 59 smokers. The lung was divided into upper (above the carina tracheae) and lower (below the carina tracheae) zones, and the degree of emphysema was graded with a subjective and an objective measurement. Functional emphysema was defined as a diffusion capacity less than 75% of predicted and forced expiratory volume in 1 second less than 80% of predicted. Three of 15 (20%) subjects with functional emphysema had no subjective evidence of emphysema at high-resolution CT, and 10 of 25 (40%) with emphysema at high-resolution CT had no functional abnormalities consistent with emphysema. Even though the upper lung zones were more severely affected by emphysema, the degree of emphysema in the lower zones had a stronger correlation with pulmonary function abnormalities. The upper lung zones are a relatively silent region where extensive destruction may occur before functional abnormalities become known.