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Relative Dispersion In The Subsurface North Atlantic, J. H. Lacasce, A. Bower Jan 2000

Relative Dispersion In The Subsurface North Atlantic, J. H. Lacasce, A. Bower

Journal of Marine Research

Pair statistics are calculated for subsurface floats in the North Atlantic. The relative diffusivity (the derivative of the mean square particle separation) is approximately constant at large scales in both eastern and western basins, though the implied scale of the energy-containing eddies is greater in the west. But the behavior at times soon after pair deployment is quite different in the two basins; in the west the diffusivity grows approximately as distance to the 4/3 power, consistent with an inverse turbulent cascade of energy (or possibly of mixing superimposed on a mean shear), but in the east the diffusivity grows …

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Buoyancy-Forced Circulations Around Islands And Ridges, Michael A. Spall Jan 2000

Buoyancy-Forced Circulations Around Islands And Ridges, Michael A. Spall

Journal of Marine Research

Observations, theory, and modeling studies indicate that dominant components of both the upwelling and downwelling limbs of the thermohaline circulation take place near boundaries and in regions of steep and/or rough topography. Analytic and numerical results are used here to show that the interaction of upwelling regions with lateral boundaries fundamentally alters the resulting large-scale circulation compared to cases of open ocean upwelling. For narrow upwelling regions, viscous fluxes emerge as a leading term in the potential vorticity budget. The strong horizontal recirculation gyres that are found for sub-basin-scale open ocean upwelling (β-plumes) are replaced by weak, unidirectional flow into …

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Islands As Eddy Splitters, Harper Lightfoot Simmons, Doron Nof Jan 2000

Islands As Eddy Splitters, Harper Lightfoot Simmons, Doron Nof

Journal of Marine Research

Previous theoretical work has shown that, in an unbounded domain, anticyclones are prohibited from splitting on their own due to limitations imposed by the conservation of angular momentum. By explicitly considering the role of angular momentum exchange between eddies and boundaries (neglected by previous theories), splitting criteria for an anticyclonic lens colliding with a long and thin island are established analytically. The inviscid analytical model consists of an isolated patch of fluid in a reduced gravity regime. Nonlinear analytical solutions are constructed by connecting the initial and final states using conserved quantities (integrated angular momentum, vorticity and mass) and the …

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Circulation At The Western Boundary Of The South And Equatorial Atlantic: Exchanges With The Ocean Interior, Nicolas Wienders, Michel Arhan, Herlé Mercier Jan 2000

Circulation At The Western Boundary Of The South And Equatorial Atlantic: Exchanges With The Ocean Interior, Nicolas Wienders, Michel Arhan, Herlé Mercier

Journal of Marine Research

Data from a hydrographic section carried out in January-March 1994 offshore from the eastern coast of South America from 50S to 10N, are used to quantify the full-depth exchanges of water between the western boundary currents and the ocean interior. In the upper and intermediate layers, the westward transport associated with the southern branch of the South Equatorial Current was 49 Sv at the time of the cruise. The transports of the central and northern branches in the upper 200 m were 17 Sv and 12 Sv, respectively. After subtraction of the parts that recirculate in the subtropical, subequatorial, and …

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Strategies For Success In Human Development, Gustav Ranis, Frances Stewart Jan 2000

Strategies For Success In Human Development, Gustav Ranis, Frances Stewart

Discussion Papers

No abstract provided.

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Validation Of A Whole Blood Serology Test For Diagnosing Helicobacter Pylori In Chinese Patients, Matthew S. Falk Jan 2000

Validation Of A Whole Blood Serology Test For Diagnosing Helicobacter Pylori In Chinese Patients, Matthew S. Falk

Yale Medicine Thesis Digital Library

No abstract provided.

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Protease Inhibitor Therapy In Hiv-Infected Children : Effects On Viral Load And Cd4+ T-Lymphocyte Counts, Naomi Lustman Katz Jan 2000

Protease Inhibitor Therapy In Hiv-Infected Children : Effects On Viral Load And Cd4+ T-Lymphocyte Counts, Naomi Lustman Katz

Yale Medicine Thesis Digital Library

No abstract provided.

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The Sequential Schedule For Poliovirus Immunization: Factors Associated With Its Adoption By Primary Care Providers, Melissa Sharyn Ellis Jan 2000

The Sequential Schedule For Poliovirus Immunization: Factors Associated With Its Adoption By Primary Care Providers, Melissa Sharyn Ellis

Yale Medicine Thesis Digital Library

No abstract provided.

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The Banking Industry In Colombia: Competition, Consolidation And Systemic Stability, Josè Darìo Uribe Jan 2000

The Banking Industry In Colombia: Competition, Consolidation And Systemic Stability, Josè Darìo Uribe

Documents

No abstract provided.

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Ofheo Freddie Mac Report Of Examination, Scott G. Calhoun Jan 2000

Ofheo Freddie Mac Report Of Examination, Scott G. Calhoun

Documents

The start to this document contains a cover letter from Scott Calhoun to Maud Mater

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Mutations In Yeast Methionine Aminopeptidase-2 Interfere With Binding Of The Anti-Angiogenic Agent Fumagillin, John Alexander Abraham Jan 2000

Mutations In Yeast Methionine Aminopeptidase-2 Interfere With Binding Of The Anti-Angiogenic Agent Fumagillin, John Alexander Abraham

Yale Medicine Thesis Digital Library

No abstract provided.

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Risk Factors Associated With The Development Of Preeclampsia In Adolescents, Amy Link Winkelstein Jan 2000

Risk Factors Associated With The Development Of Preeclampsia In Adolescents, Amy Link Winkelstein

Yale Medicine Thesis Digital Library

No abstract provided.

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Management Of Acute Myocardial Infarction In Veterans : A Study According To Hospital Sophistication, Jody Alpert Levine Jan 2000

Management Of Acute Myocardial Infarction In Veterans : A Study According To Hospital Sophistication, Jody Alpert Levine

Yale Medicine Thesis Digital Library

No abstract provided.

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Quality Of Life And Facial Trama Psychological And Body Image Effects, Elie Levine Jan 2000

Quality Of Life And Facial Trama Psychological And Body Image Effects, Elie Levine

Yale Medicine Thesis Digital Library

No abstract provided.

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Localization Of Gfp-Rad52 In Stable Human Cell Lines, Rachel Lovins Jan 2000

Localization Of Gfp-Rad52 In Stable Human Cell Lines, Rachel Lovins

Yale Medicine Thesis Digital Library

No abstract provided.

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Improving Marine Ecosystem Models: Use Of Data Assimilation And Mesocosm Experiments, J. J. Vallino Jan 2000

Improving Marine Ecosystem Models: Use Of Data Assimilation And Mesocosm Experiments, J. J. Vallino

Journal of Marine Research

Our inability to accurately model marine food webs severely limits the prognostic capabilities of current generation marine biogeochemistry models. To address this problem we examine the use of data assimilation and mesocosm experiments to facilitate the development of food web models. The components of the data assimilation demonstrated include the construction of measurement models, the adjoint technique to obtain gradient information on the objective function, the use of parameter constraints, incorporation of discrete measurements and assessing parameter observability. We also examine the effectiveness of classic and contemporary optimization routines used in data assimilation. A standard compartment-type food web model is …

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Distributions Of Top, Ton And Toc In The North Pacific Subtropical Gyre: Implications For Nutrient Supply In The Surface Ocean And Remineralization In The Upper Thermocline, Jeffrey Abell, Steve Emerson, Paul Renaud Jan 2000

Distributions Of Top, Ton And Toc In The North Pacific Subtropical Gyre: Implications For Nutrient Supply In The Surface Ocean And Remineralization In The Upper Thermocline, Jeffrey Abell, Steve Emerson, Paul Renaud

Journal of Marine Research

We report measurements of total organic phosphorus, nitrogen, and carbon (TOP, TON, and TOC) along a meridional transect in the eastern subtropical North Pacific. In the surface waters, TOP and TON comprise 83% and 98% of the total dissolved phosphorus and nitrogen pools, respectively. Between the equatorial region and the subtropical gyre, there is a distinct gradient in surface TOP of about 0.25 µM, but very little gradient in TON. TOC increases by nearly 30 µM across the same region. Meridional advection of TOP along its gradient via Ekman transport can provide 40-80% of the phosphorus necessary to supply present …

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Mechanism Of Eddy Separation From Coastal Currents, Melvin E. Stern, Eric P. Chassignet Jan 2000

Mechanism Of Eddy Separation From Coastal Currents, Melvin E. Stern, Eric P. Chassignet

Journal of Marine Research

A series of multi-layer numerical experiments show that classical finite amplitude instabilities in boundary currents are not sufficient to account for the pinched-off eddies observed in the ocean and in laboratory experiments. These instabilities (barotropic or baroclinic) are shown to lead to an entrainment of offshore fluid into the boundary currents. Eddy separation, on the other hand, requires an additional process, such as a larger scale of motion containing a downstream velocity convergence of finite amplitude; this might be produced by long period fluctuations in the discharge from an upstream source region which controls the boundary current, or by topographic …

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Modeling Δ15n Evolution: First Palaeoceanographic Applications In A Coastal Upwelling System, Xavier Giraud, Philippe Bertrand, Véronique Garçon, Isabelle Dadou Jan 2000

Modeling Δ15n Evolution: First Palaeoceanographic Applications In A Coastal Upwelling System, Xavier Giraud, Philippe Bertrand, Véronique Garçon, Isabelle Dadou

Journal of Marine Research

The δ15N signal in marine sediments appears to be a good palaeoceanographic tracer. It records biological processes in the water column and is transferred to and preserved in the sediments. Changes in forcing factors in upwelling systems may be recorded by δ15N. These forcing conditions can be of a biogeochemical nature, such as the initial isotopic signal of the nutrients or the trophic structure, or of a physical nature, such as wind stress, insolation, temperature or dynamic recycling. A simple nitrogen-based trophic chain model was used to follow the development of the nitrogen isotopic signal in …

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Abyssal Upwelling In The Indian Ocean: Radiocarbon Diagnostics, Ashwanth Srinivasan, Claes G. H. Rooth, Zafer Top, D. B. Olson Jan 2000

Abyssal Upwelling In The Indian Ocean: Radiocarbon Diagnostics, Ashwanth Srinivasan, Claes G. H. Rooth, Zafer Top, D. B. Olson

Journal of Marine Research

The GEOSECS Indian Ocean radiocarbon and carbonate chemistry data set are used to estimate the mean upwelling transport of bottom water in the Indian Ocean north of 30S. The study uses an "adjusted radiocarbon concentration" which is corrected for the effects of addition of particulate radiocarbon to the deep ocean. The cross-basin uniformity in the vertical gradients of "adjusted radiocarbon" allows quantification of vertical transfer processes using horizontally averaged concentration and fluxes. The estimated total upwelling flux, north of 30S, is 8.2 ± 1.5 × 106 m3 s-1. The mean upwelling velocity and the vertical diffusivity, …

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On The Use Of The Method Of Images To Investigate Nearshore Dynamical Processes, S. A. Thorpe, L. R. Centurioni Jan 2000

On The Use Of The Method Of Images To Investigate Nearshore Dynamical Processes, S. A. Thorpe, L. R. Centurioni

Journal of Marine Research

This note describes how the method of images may be used to determine the motion and evolution of two related kinds of phenomena within a wedge of inviscid fluid. The image field of a curved vortex within a wedge with vortex lines lying along sectors of circles around the apex of the wedge is that segment of a complete vortex ring which remains outside the wedge and of which the curved vortex forms a part. The image system can be used to describe the motion, interaction and stability of single or multiple vortices within the wedge. Axisymmetric jets form the …

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Water-Mass Formation And Potential Vorticity Balance In An Abyssal Ocean Circulation, Jiayan Yang, James F. Price Jan 2000

Water-Mass Formation And Potential Vorticity Balance In An Abyssal Ocean Circulation, Jiayan Yang, James F. Price

Journal of Marine Research

Our goal is to develop some understanding and intuition regarding abyssal ocean circulations. To do this we investigate highly idealized, source/sink-driven flows computed by a single layer, numerical ocean model forced by a prescribed source or sink. The interior circulation is always found to be very slow and Stommel-Arons like. On the other hand, the intense boundary currents may vary considerably from case to case, depending largely upon the potential vorticity (PV) associated with the source or sink. If the source is imposed by downwelling along a northern boundary, then the associated PV flux is zero, and the resulting steady …

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The Parameterization Of Baroclinic Instability In A Simple Model, A. Wirth Jan 2000

The Parameterization Of Baroclinic Instability In A Simple Model, A. Wirth

Journal of Marine Research

Baroclinic instability of zonally forced flow in a two mode quasi-geostrophic numerical model with periodic boundary conditions is considered. Only the largest scale of the baroclinic mode is forced and the scale dependence of a diffusive parameterization of baroclinic layer thickness is determined. It is shown that the effect of baroclinic instability is a decreasing function of scale with an exponent of about half of that corresponding to the commonly used Laplace operator. We furthermore show that there is no linear relation between the time averaged amplitude of the large scale streamfunction (or quasi-geostrophic potential vorticity) and the bolus velocity.

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Low-Frequency Variability On The Western Flanks Of The Grand Banks, Nelson G. Hogg Jan 2000

Low-Frequency Variability On The Western Flanks Of The Grand Banks, Nelson G. Hogg

Journal of Marine Research

An array consisting of 21 current meters on nine moorings was set on the western flanks of the Grand Banks in August 1995 and recovered about two years later. The purpose was to explore the possibility that this might be a region of anomalously high topographic wave activity because the local topography so altered the dispersion relation for these waves that they could couple more readily to eastward-moving Gulf Stream meanders. Eddy kinetic energy is, indeed, found to be higher here than elsewhere in the region but only at periods shorter than about 10 days. At longer periods energy in …

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Modeling Of The Bottom Water Flow Through The Romanche Fracture Zone With A Primitive Equation Model—Part I: Dynamics, Bruno Ferron, Herlé Mercier, Anne-Marie Treguier Jan 2000

Modeling Of The Bottom Water Flow Through The Romanche Fracture Zone With A Primitive Equation Model—Part I: Dynamics, Bruno Ferron, Herlé Mercier, Anne-Marie Treguier

Journal of Marine Research

This paper investigates the dynamics of the Antarctic Bottom Water (AABW) flow through the Romanche Fracture Zone (RFZ) in a primitive equation model with a high horizontal and vertical resolution. Two examples of flows over simple bathymetries show that a reduced gravity model captures the essential dynamics of the primitive equation model. The reduced gravity model is then used as a tool to identify what are the bathymetric structures (sills, narrows) that mostly constrain theAABW flow through the RFZ. When only these structures are represented in the primitive equation model, the AABW flow is shown to be coherent with observations …

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Properties Of Vertical Current Shear Across Stratification In The North Sea, Hans Van Haren Jan 2000

Properties Of Vertical Current Shear Across Stratification In The North Sea, Hans Van Haren

Journal of Marine Research

Observations from the central North Sea show that, as soon as thermal stratification becomes established by solar insolation in the spring, the vertical smoothly varying horizontal current structure observed in winter becomes distorted, with strongest vertical shear coincident with the strongest buoyancy gradients (thermoclines). This shear is predominant at the local inertial frequency following strong wind-forcing or when the thermocline thickness is relatively large, and the semidiurnal tidal frequency otherwise. Although the currents at these frequencies have a completely different character, being circularly polarized and mode-1 at the inertial frequency and almost rectilinear and barotropic at the tidal frequency, their …

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Climate Change And Development, Luis Gómez-Echeverri Jan 2000

Climate Change And Development, Luis Gómez-Echeverri

Yale School of the Environment Publications Series

A collaborative publication of the UNDP Regional Bureau for Latin America and the Caribbean and the Yale School of Forestry & Environmental Studies.

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Iron Uptake In Human Keratinocytes Exposed To Photodegraded Nifedipine, Alison Brett Gruen Jan 2000

Iron Uptake In Human Keratinocytes Exposed To Photodegraded Nifedipine, Alison Brett Gruen

Yale Medicine Thesis Digital Library

No abstract provided.

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The Emergence Of Compartmental Organization In The Olfactory Bulb Glomerulus, Hanna Kim Jan 2000

The Emergence Of Compartmental Organization In The Olfactory Bulb Glomerulus, Hanna Kim

Yale Medicine Thesis Digital Library

No abstract provided.

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Childhood Pneumonia In Nuwakot District, Nepal: Perceptions, Management, And The Impact Of A Community Intervention, Amy B. Levin Jan 2000

Childhood Pneumonia In Nuwakot District, Nepal: Perceptions, Management, And The Impact Of A Community Intervention, Amy B. Levin

Yale Medicine Thesis Digital Library

No abstract provided.

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