The nonlinear dynamics of unstable alongshore currents in the nearshore
surf zone over variable barred beach topography are studied using numerical
experiments. These experiments extend the recent studies of Allen et al. [1996]
and Slnn et al. [1998], which utilized alongshore uniform beach topographies by
including sinusoidal alongshore variation to...
The nonlinear dynamics of finite amplitude shear instabilities of
alongshore currents in the nearshore surf zone over barred beach topography are
studied using numerical experiments. These experiments extend the recent study
of Allen et al. [1996], which utilized plane beach (constant slope) topography by
including shore-parallel sandbars. The model involves...
Sphaeromyxa maiyai sp. n. (Myxosporidea:Myxiidae) is described
from the gall bladder of the Pacific tomcod, Microgadus proximus
Girard, from Newport, Oregon. The plasmodial (=trophic, trophozoite)
stage is discoid averaging between 1 and 2 cm. The spore averages
27.6 x 5. 6μm with pyriform polar capsules averaging 9. 3 x 3....
Capturing breeding adults of colonially nesting species can entail risks of nest failure and even colony abandonment, especially in species that react strongly to human disturbance. A low-disturbance technique for capturing specific adult Double-crested Cormorants (Phalacrocorax auritus) at a ground-nesting colony was developed to reduce these risks and is described...
Double-crested cormorants (Phalacrocorax auritus) have been identified as the source of significant mortality to juvenile salmonids (Oncorhynchus spp.) in the Columbia River Basin. Management plans for reducing the size of a large colony on East Sand Island (OR, USA) in the Columbia River estuary are currently being developed. We evaluated...
Published April 1973. Facts and recommendations in this publication may no longer be valid. Please look for up-to-date information in the OSU Extension Catalog: http://extension.oregonstate.edu/catalog
Epidemics of infectious diseases often occur in predictable limit cycles. Theory suggests these cycles can be disrupted by high amplitude seasonal fluctuations in transmission rates, resulting in deterministic chaos. However, persistent deterministic chaos has never been observed, in part because sufficiently large oscillations in transmission rates are uncommon. Where they...
Epidemics of infectious diseases often occur in predictable limit cycles. Theory suggests these cycles can be disrupted by high amplitude seasonal fluctuations in transmission rates, resulting in deterministic chaos. However, persistent deterministic chaos has never been observed, in part because sufficiently large oscillations in transmission rates are uncommon. Where they...
Full Text:
Transmission
Patterns
Benjamin D. Dalziel1¤, Ottar N. Bjørnstad2, Willem G. van Panhuis3, Donald S. Burke4, C
