Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 8 of 8
Full-Text Articles in Life Sciences
Pfiesteria: Review Of The Science And Identification Of Research Gaps. Report For The National Center For Environmental Health, Centers For Disease Control And Prevention, Jonathan Samet, Gary S. Bignami, Robert Feldman, William E. Hawkins, Jerry Neff, Theodore Smayda
Pfiesteria: Review Of The Science And Identification Of Research Gaps. Report For The National Center For Environmental Health, Centers For Disease Control And Prevention, Jonathan Samet, Gary S. Bignami, Robert Feldman, William E. Hawkins, Jerry Neff, Theodore Smayda
Faculty Publications
In connection with the CDC National Conference on Pfiesteria, a multidisciplinary panel evaluated Pfiesteria-related research. The panel set out what was known and what was not known about adverse effects of the organism on estuarine ecology, fish, and human, health; assessed the methods used in Pfiesteria research; and offered suggestions to address data gaps. The panel's expertise covered dinoflagellate ecology; fish pathology and toxicology; laboratory measurement of toxins, epidemiology, and neurology. The panel evaluated peer-reviewed and non-peer-reviewed literature available through June 2000 in a systematic conceptual framework that moved from the source of exposure, through exposure research and dose, to …
Effects Of River Inputs Into The Bay Of Bengal, Stephan D. Howden, Raghu Murtugudde
Effects Of River Inputs Into The Bay Of Bengal, Stephan D. Howden, Raghu Murtugudde
Faculty Publications
The effect of river runoff in the Bay of Bengal is examined using a reduced gravity primitive equation ocean model coupled to an atmospheric boundary layer model. Model simulations are carried out by including river discharges as surface freshwater forcing at the mouths of the rivers. To assess the effect of river inputs on the dynamics and thermodynamics of the tropical Indian Ocean, parallel simulations are carried out by neglecting the river inputs. Additionally, another set of parallel runs without penetrative radiation loss through the mixed layer is carried out. The freshwater flux due to rivers results in lower salinities …
Experimental Evaluation Of Vitellogenin As A Predictive Biomarker For Reproductive Disruption, Ann Oliver Cheek, Thea Hoexum Brouwer, Suzanne Carroll, Steve Manning, John A. Mclachlan, Marius Brouwer
Experimental Evaluation Of Vitellogenin As A Predictive Biomarker For Reproductive Disruption, Ann Oliver Cheek, Thea Hoexum Brouwer, Suzanne Carroll, Steve Manning, John A. Mclachlan, Marius Brouwer
Faculty Publications
Vitellogenin (VTG) synthesis in male oviparous vertebrates is used as an indicator of environmental estrogen exposure, but the relationship between elevated VTG levels and the effects of environmental estrogens on reproductive success are poorly understood. To examine whether altered VTG expression predicts reproductive impairment, we exposed medaka (Oryzias latipes) for 2 or 8 weeks posthatch to 0, 0.5, 1.0, 2.5, and 7.5 ppb of the environmental estrogen o,p ' -DDT. Fish were sampled 2, 4, and 8 weeks after hatch to examine VTG expression and gonad development. After exposure, fish were transferred to clean water, grown to sexual maturity, and …
Chloropigment Distribution And Transport On The Inner Shelf Off Duck, North Carolina, Eurico J. D'Sa, Steven E. Lohrenz, James H. Churchill, Vernon L. Asper, John L. Largier, Albert J. Williams Iii
Chloropigment Distribution And Transport On The Inner Shelf Off Duck, North Carolina, Eurico J. D'Sa, Steven E. Lohrenz, James H. Churchill, Vernon L. Asper, John L. Largier, Albert J. Williams Iii
Faculty Publications
The distribution and movement of chloropigments (chlorophylls and associated degradation products) in the bottom boundary layer near Duck, North Carolina, were examined during July and August 1994. Time series of chloropigment fluorescence, current velocity, and surface wave properties were acquired from instruments mounted on a bottom tripod set at 20 m depth. These data were combined with moored current meter measurements, meteorological data, and shipboard surveys in a comparative assessment of physical processes and chloropigment distribution over a wide range of temporal and spatial scales. Two dominant scales of chloropigment variation were observed. On numerous occasions, small-scale (order m) structure …
Seasonal Variation Of The North Atlantic Current, Max I. Yaremchuk, Dmitri A. Nechaev, Keith R. Thompson
Seasonal Variation Of The North Atlantic Current, Max I. Yaremchuk, Dmitri A. Nechaev, Keith R. Thompson
Faculty Publications
The seasonal circulation of the upper 1000 m of the North Atlantic between 40 degrees -55 degreesN and 20 degrees -40 degreesW is calculated using the traditional dynamic method and a circulation model with a density field that evolves with the flow. The model is of finite difference form and is based on dynamics that describe the nonlinear evolution of the ocean at low Rossby number. The model is controlled by initial and boundary conditions that include air-sea buoyancy and momentum fluxes. The model is run in two ways: with controls specified directly from observations and with controls inferred by …
Reproductive Biology Of Cobia, Rachycentron Canadum, From Coastal Waters Of The Southern United States, Nancy J. Brown-Peterson, Robin M. Overstreet, Jeffrey M. Lotz, James S. Franks, Karen M. Burns
Reproductive Biology Of Cobia, Rachycentron Canadum, From Coastal Waters Of The Southern United States, Nancy J. Brown-Peterson, Robin M. Overstreet, Jeffrey M. Lotz, James S. Franks, Karen M. Burns
Faculty Publications
Reproductive biology of the cobia, Rachycentron canadum, is described from four coastal areas in the southern United States. Samples were obtained from recreational fishermen between December 1995 and November 1997 from the southeastern United States (Morehead City, NC, to Cape Canaveral, FL), the eastern Gulf of Mexico (Ft. Myers to Crystal River, FL), the north-central Gulf of Mexico (Destin, FL, to Chandeleur Islands, LA) and the western Gulf of Mexico (Port Aransas, TX). Histological evidence of spawning occurred from April through September in all areas. Some female cobia (17-32%) throughout the Gulf of Mexico had spent or regressed ovaries by …
Simulations Of Quasigeostrophic Currents Derived From Satellite Altimetry And Acoustic Tomography Of An Open Ocean Region, Max I. Yaremchuk, Dmitri A. Nechaev
Simulations Of Quasigeostrophic Currents Derived From Satellite Altimetry And Acoustic Tomography Of An Open Ocean Region, Max I. Yaremchuk, Dmitri A. Nechaev
Faculty Publications
Acoustic tomography (AT) and satellite altimetry (SA) measure properties of the ocean state with high temporal resolution. That makes these data suitable for long-term monitoring of mesoscale features in the open ocean regions, where the open boundaries are the major sources of model forecast uncertainties on timescales larger than 1 week. In this paper, a finite-difference quasigeostrophic model of an open ocean region is considered as a possible tool for interpolating AT-SA data in space and time. The assimilation algorithm is based upon the 4D variational data assimilation scheme controlled by the initial and boundary conditions of the model. The …
Identifying A Damped Oscillatory Thermohaline Mode In A General Circulation Model Using An Adjoint Model, Ziv Sirkes, Eli Tziperman
Identifying A Damped Oscillatory Thermohaline Mode In A General Circulation Model Using An Adjoint Model, Ziv Sirkes, Eli Tziperman
Faculty Publications
A damped oscillatory mode of the thermohaline circulation (THC), which may play a role in interdecadal climate variability, is identified in a global primitive equation model. This analysis is done under mixed boundary conditions using an adjoint of the primitive equation model. The linearized versus nonlinear stability behavior of the model is studied by comparing the adjoint analysis to runs of the fully nonlinear model. It is shown that a steady-state solution obtained under larger amplitude freshwater surface forcing (and hence with a weaker North Atlantic overturning) is unstable, while a steady-state solution with stronger THC is stable. In a …