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Primary And New Production In The Thermocline Ridge Region Of The Southern Indian Ocean During The Summer Monsoon, Naveen Gandhi, R. Ramesh, S. Prakash, Sharon Noronha, N. Anilkumar

Journal of Marine Research

New and primary production, measured using ¹⁵N and ¹³C tracers, integrated over the euphotic zone (mostly upper 80–100 m) varied from 7.5 to 14.1 mmol N m^–2d^–1(average 10.8 mmol N m^–2d^–1) and 2.7 to 17.7 mmol C m^–2d^–1 (average 11.3 mmol C m^–2d^–1), respectively, in the tropical India Ocean (TIO). Shoaling of thermocline in the thermocline ridge located in the tropical Indian Ocean (TR) influences new and total productivity by supplying nutrients to the upper layers. At the same time, N-limited conditions prevail …

Geostrophic Ocean Currents And Freshwater Fluxes Across The Canadian Polar Shelf Via Nares Strait, Berit Rabe, Helen L. Johnson, Andreas Münchow, Humfrey Melling

Journal of Marine Research

This study discusses geostrophic ocean currents and fluxes through Nares Strait, one of the major straits connecting the Arctic Ocean to the North Atlantic across the Canadian polar shelf. Between 2003 and 2006, instruments were installed on subsea moorings to measure conductivity, temperature, pressure and velocity at high temporal and spatial resolution across the 400-m-deep strait. Here we present estimates of the variable volume and liquid freshwater fluxes, derived by geostrophic calculation, through the fraction of the cross section measured by the array. The array of conductivity-temperature recorders spanned 30 km of a 38-km-wide section between 30- and 200-m depth. …

Solar Warming Of Near-Bottom Water Over A Fringing Reef, Judith R. Wells, Jonathan P. Fram, Geno Pawlak

Journal of Marine Research

The Kilo Nalu Observatory is located on the foreslope of a fringing reef on the south shore of Oahu, Hawaii. A cabled node at 12-m depth has enabled continuous real-time temperature observations from a thermistor chain extending from 1 to 7 m above bottom. Data from a 27-month deployment in 2007–2009 reveal repeated instances of subsurface temperature inversions. The usual diurnal pattern shows increases in temperature throughout the water column after sunrise, peaking in the early afternoon. Bottom waters typically warm faster than those at mid-depth, driving an inversion in the thermal profile. The onset and evolution of the inversions …

Experimental Assessment Of Particle Mixing Fingerprints In The Deposit-Feeding Bivalve Abra Alba (Wood), Guillaume Bernard, Antoine Grémare, Olivier Maire, Pascal Lecroart, Filip J. R. Meysman, Aurélie Ciutat, Bruno Deflandre, Jean Claude Duchêne

Journal of Marine Research

Particle mixing induced by the deposit-feeding bivalve Abra alba was assessed using a new experimental approach allowing for the tracking of individual particle displacements. This approach combines the adaptation of existing image acquisition techniques with new image analysis software that tracks the position of individual particles. This led to measurements of particle mixing fingerprints, namely the frequency distributions of particle waiting times, and of the characteristics (i.e. direction and length) of their jumps. The validity of this new approach was assessed by comparing the so-measured frequency distributions of jump characteristics with the current qualitative knowledge regarding particle mixing in the …

Craving And Quitting: An Exploration Of How Mindfulness Training May Help Smokers To Quit, Hani Elwafi

Yale Medicine Thesis Digital Library

Abstract

Authors: Hani M. Elwafi, Katie Witkiewitz, Sarah Mallik, Thomas Thornhill IV, Judson Alyn Brewer

Cigarette smoking is the leading cause of preventable deaths in the world. A majority of smokers identify tobacco as harmful and express a desire to quit. Currently available treatments have shown only modest success, and abstinence rates remain low. Mindfulness Training (MT) shows promise as an effective treatment for smoking cessation, yet the mechanisms remain unclear. Craving has been shown to be a central component of the addictive process, and a strong predictor of smoking. MT is theorized to work by dismantling this addictive process …

Utility Of Apparent Diffusion Coefficients In The Evaluation Of Primary Central Nervous System Lymphoma, John Webster Gilbert

Yale Medicine Thesis Digital Library

The characterization of primary central nervous system lymphoma (PCNSL) via noninvasive imaging modalities is essential for early diagnosis and differentiation from other brain lesions. Diffusion-weighted magnetic resonance imaging (DW-MRI), in which intensity of image contrast reflects diffusion of water molecules by Brownian motion, offers additional information beyond that obtained from conventional MRI. In this retrospective study from two institutions, quantitative region of interest (ROI) analysis was performed using parametric apparent diffusion coefficient (ADC) maps in immunocompetent patients with newly diagnosed PCNSL prior to corticosteroid use or other therapy. Mean ADC values and ratios were calculated for PCNSL lesions, peritumoral edema, …

Tissue-Engineered Vascular Grafts Allow Neovessel Formation By Recruiting Adjacent Vascular Tissue, Adam Shoffner

Yale Medicine Thesis Digital Library

Hypothesis: Tissue Engineered Vascular Grafts (TEVGs) constructed by seeding cells autologous bone marrow-derived mononuclear cells onto dissolvable scaffolding aid in the recruitment of cells from either the host's bone marrow or neighboring vasculature to form the graft neotissue.

Methods: RT-PCR was performed on explanted grafts to detect presence of seeded cells. FISH for Y chromosome was performed on female mice with male bone marrow transplant along with female mice with implanted male-composite TEVG.

Results: The seeded cells on implanted TEVGs decrease precipitously from 4.37% to 0.02% from 6hr to 14 days. At 6 months post implantation composite graft TEVGs displayed …

Predicting Disengagement From Care In An Early Psychosis Patient Cohort In The United States, Matthew Kruse

Yale Medicine Thesis Digital Library

The current study aims to assess baseline variables which may predict disengagement from care among patients with psychosis seeking treatment at an early intervention clinic in the United States. Based on literature published at sites outside the United States, we predict that duration of untreated psychosis, global assessment of functioning, forensic history, family contact, and substance abuse are predictive of disengagement during the first year of outpatient treatment. Patients were grouped according to whether or not they disengaged from care in a one year follow-up, and compared them on the above discrete and continuous variables with chi-square analysis and Student‟s …

Eddy Viscosity And Diffusivity In The Modon-Sea Model, Timour Radko

Journal of Marine Research

A deterministic model is developed to evaluate and explain the rate of dissipation of momentum in eddying oceanic flows. Theory is based on a classical conceptualization of mesoscale variability – Stern's modon-sea solution – which represents a closely packed array of steady compact dipolar vortices on the barotropic beta-plane. In our model, the periodic modon-sea pattern is subjected to a large-scale perturbation, weakly modulating the amplitude of the individual modons. The asymptotic multiscale analysis makes it possible to explicitly describe the interaction between the modon-sea eddies and the perturbing flow. This interaction results in a systematic weakening of the large-scale …

Measuring Overturns With Gliders, S. A. Thorpe

Journal of Marine Research

The accuracy of the estimation of the vertical size of eddies in turbulent stratified shear flows in the ocean from measurements obtained by gliders is examined. It is assumed that gliders move along paths inclined at moderate angles to the horizontal. Comparison is made with measurements by probes falling or lowered vertically through billows resulting from Kelvin-Helmholtz (K-H) or Holmboe instability and through the statically unstable regions formed at early stages of convective breaking of internal waves. The probable errors involved in estimating the overturn scale of a K-H billow along the track of a glider are greatest when the …

Glider Measurements Of Overturning In A Kelvin-Helmholtz Billow Train, W. D. Smyth, S. A. Thorpe

Journal of Marine Research

The prospects for glider-based measurement of turbulence statistics are assessed using direct numerical simulation data representing breaking Kelvin-Helmholtz (KH) billows in a stratified, parallel shear flow. Transects tilted upstream against the shear tend to produce overestimates of overturning; those tilted with the shear produce underestimates. Low-angle transects can produce illusory overturning as the braid between the KH billows is crossed. Statistical features of the bias in displacement scales are related to geometrical aspects of KH billows. Results are interpreted in the context of a hypothetical effort to characterize overturning in a strongly sheared current (e.g. the Equatorial Undercurrent) using nonvertical …

Cross-Shelf Mixing And Mid-Shelf Front Dynamics In The Mid-Atlantic Bight Evaluated Using The Radium Quartet, Scott L. Stachelhaus, S. Bradley Moran, David S. Ullman, Roger P. Kelly

Journal of Marine Research

Mid-shelf fronts (MSFs) are thought to be ubiquitous in shelf areas. However, their dynamical role in cross-shelf mixing has yet to be fully characterized. In January, February, and April of 2007, radium isotopes (²²³Ra, t_1/2 = 11 d; ²²⁴Ra, t_1/2 = 3.7 d; ²²⁶Ra, t_1/2 = 1600 yr; ²²⁸Ra, t_{1/2 = 5.7 yr) were measured along a transect in the Mid-Atlantic Bight to constrain mixing rates at and around a MSF. Cross-shelf eddy diffusivities (Kx) were determined from ²²³Ra and ²²⁴Ra distributions using a variable-depth model. Two key assumptions …}

Development Of Resistance To An Introduced Marine Pathogen By A Native Host, Susan E. Ford, David Bushek

Journal of Marine Research

In 1957–1959, the introduced protistan parasite, Haplosporidium nelsoni, killed 90–95% of the oysters (Crassostrea virginica) in lower Delaware Bay and about half of those in the upper bay. Shortly thereafter, H. nelsoni-caused mortality in the wild population of the lower bay declined, approximating that of first-generation selectively bred oysters. For nearly three decades thereafter no further change in survival of the wild population was evident, although steady improvement was achieved by continued selective breeding. Survival of the wild population is thought to have plateaued because the great majority of oysters inhabited the upper bay where they …

Effective Population Sizes Of Eastern Oyster Crassostrea Virginica (Gmelin) Populations In Delaware Bay, Usa, Yan He, Susan E. Ford, David Bushek, Eric N. Powell, Zhenmin Bao, Ximing Guo

Journal of Marine Research

Effective population size (N_e) is an important concept in population genetics as it dictates the rate of genetic change caused by drift. N_e estimates for many marine populations are small relative to the census population size. Small N_e in a large population may indicate high reproductive variance or sweepstakes reproductive success (SRS). The eastern oyster (Crassostrea virginica) may be prone to SRS due to its high fecundity and high larval mortality. To examine if SRS occurs in the eastern oyster, we studied N_e and genetic variation of oyster populations in Delaware Bay. …

Modeling The Dispersal Of Eastern Oyster (Crassostrea Virginica) Larvae In Delaware Bay, Diego A. Narváez, John M. Klinck, Eric N. Powell, Eileen E. Hofmann, John Wilkin, Dale B. Haidvogel

Journal of Marine Research

The interactions of circulation and growth processes in determining the horizontal distribution of eastern oyster (Crassostrea virginica) larvae in the Delaware Bay estuary were investigated with a coupled circulation-individual-based larvae model that used environmental conditions from the spawning seasons (mid-June to mid-September) of 1984, 1985, 1986, 2000, and 2001. Particles, representing oyster larvae, were released at five-day intervals from areas in Delaware Bay that correspond to natural oyster reefs. The simulated larval development time was used to estimate potential larval success, determined by the percent of larvae that successfully reached settlement size (330 μm) within the planktonic larval …

Reconciling Float-Based And Tracer-Based Estimates Of Lateral Diffusivities, Andreas Klocker, Raffaele Ferrari, Joseph H. Lacasce, Sophia T. Merrifield

Journal of Marine Research

Lateral diffusivities are computed from synthetic particles and tracers advected by a velocity field derived from sea-surface height measurements from the South Pacific, in a region west of Drake Passage. Three different estimates are compared: (1) the tracer-based “effective diffusivity” of Nakamura (1996), (2) the growth of the second moment of a cloud of tracer and (3) the single- and two-particle Lagrangian diffusivities. The effective diffusivity measures the cross-stream component of eddy mixing, so this article focuses on the meridional diffusivities for the others, as the mean flow (the ACC) is zonally oriented in the region. After an initial transient …

Intermittent Bioirrigation And Oxygen Dynamics In Permeable Sediments: An Experimental And Modeling Study Of Three Tellinid Bivalves, Nils Volkenborn, Christof Meile, Lubos Polerecky, Conrad A. Pilditch, Alf Norkko, Joanna Norkko, Judi E. Hewitt, Simon F. Thrush, David S. Wethey, Sarah A. Woodin

Journal of Marine Research

To explore the dynamic nature of geochemical conditions in bioirrigated marine permeable sediments, we studied the hydraulic activity of three tellinacean bivalve molluscs (the Pacific species Macoma nasuta and Macomona liliana, and the northern Atlantic and Pacific species Macoma balthica). We combined porewater pressure sensing, time-lapse photography and oxygen imaging to quantify the durations and frequencies of tellinid irrigation activity and the associated oxygen dynamics in the sediment. Porewater pressure records of all tellinids were dominated by intermittent porewater pressurization, induced by periodic water injection into the sediment through their excurrent siphons, which resulted in intermittent oxygen supply …

Deep Circulation In The Eastern South Pacific Ocean, Vincent Faure, Kevin Speer

Journal of Marine Research

We use an inverse method to compute the deep circulation in the eastern South Pacific Ocean, on isopycnal layers within the depth range of 1,000–3,000 m. The method gives probability density functions of the isopycnal and diapycnal velocities and diffusivities on a grid with a realistic eastern boundary, based on tracer fields. An oxygen consumption rate, assumed spatially constant, controls the solution effectiveness (minimum value of the model cost function) and the magnitude of the diffusivities. The isopycnal circulation is, by contrast, less dependent on the consumption rate. Direct deep float displacement data is used as a check on our …

The Role Of Larval Dispersal In Metapopulation Gene Flow: Local Population Dynamics Matter, Daphne M. Munroe, John .. Klinck, Eileen E. Hofmann, Eric N. Powell

Journal of Marine Research

The degree of genetic connectivity among populations in a metapopulation has direct consequences for species evolution, development of disease resistance, and capacity of a metapopulation to adapt to climate change. This study used a metapopulation model that integrates population dynamics, dispersal, and genetics within an individual-based model framework to examine the mechanisms and dynamics of genetic connectivity within a metapopulation. The model was parameterized to simulate four populations of oysters (Crassostrea virginica) from Delaware Bay on the mid-Atlantic coast of the United States. Differences among the four populations include a strong spatial gradient in mortality, a spatial gradient …

Oyster Food Supply In Delaware Bay: Estimation From A Hydrodynamic Model And Interaction With The Oyster Population, Eric N. Powell, Danielle A. Kreeger, Jason M. Morson, Dale B. Haidvogel, Zhiren Wang, Roger Thomas, Jennifer E. Gius

Journal of Marine Research

To evaluate oyster food supply, water samples were collected at fifteen sites in Delaware Bay nearmonthly in 2009 and 2010. Food was estimated as the sum of particulate protein, labile carbohydrate, and lipid. Delaware Bay shows a typical spring bloom, centered in March and April, with declining food supply thereafter into early fall, followed sporadically by a minor fall bloom. The geographic and temporal structure of food was more predictable in summer to early fall, and considerably less predictable in spring. Five variables each based on temperature and the spatial and temporal variability of temperature were significant contributors to a …

Evidence Of Vertical Coupling Between The Kuroshio Extension And Topographically Controlled Deep Eddies, Andrew D. Greene, D. Randolph Watts, Georgi G. Sutyrin, Hideharu Sasaki

Journal of Marine Research

Strong energy in the 30–60 day band was observed using 39 deep pressure and current records from the Kuroshio Extension System Study (KESS). Energy in this band accounted for 25–50% of the total deep-pressure variance and was strongest under the Kuroshio Extension jet axis. Often, deep-pressure anomalies propagated into the region from the north-northeast and locally intensified as they passed under and interacted with the Kuroshio Extension. The topographically controlled deep-pressure anomalies translate nearly along lines of constant f/H. Statistically significant coherence between 30–60 day upper- and deep-ocean streamfunction anomalies demonstrated that there was strong vertical coupling in that …

Adjustment Of A Wind-Driven Two-Layer System With Mid-Basin Topography, Magdalena Andres, Jiayan Yang, Young-Oh Kwon

Journal of Marine Research

A linear primitive equations model is used to simulate spin-up of a two-layer ocean bisected by a meridional ridge. The ocean is forced with steady zonal winds east of the ridge. When wind-driven barotropic planetary Rossby waves propagate across the ridge, barotropic and baroclinic anomalies are generated as the barotropic flow adjusts. These ridge-generated anomalies propagate westward from the ridge as planetary Rossby waves and their arrival along the basin's western boundary modulates the western boundary current (WBC) transport and vertical structure. Model results suggest that at short (<1 year) and long (>10 years) delay relative to a …

Reproducibility Of Exercise Testing In Patients With Pulmonary Arteriovenous Malformations, Bolin Niu

Yale Medicine Thesis Digital Library

Patients with pulmonary arteriovenous malformations (PAVMs) are at risk for complications, hemorrhagic and neurological, and therefore require close follow-up.

The primary hypothesis of this project poses that the exercise stress test (EST) and 6-minute walk test (6MWT) are reproducible and reliable in patients with PAVMs. Secondarily, if these tests are shown to be reproducible, they may become a surrogate follow-up tool for patients with PAVMs after quantification with non-contrast CT and may replace contrast echocardiography in asymptomatic children under age 12.

Twenty-two patients with PAVMs, most of whom had hereditary hemorrhagic telangiectasia (HHT), participated in a Human Investigations Committee-approved protocol. …

The Effect Of E-Cadherin Loss On Melanoma Formation And Metastasis, Lara Rosenbaum

Yale Medicine Thesis Digital Library

Melanoma is the most lethal form of skin cancer and accounts for the majority of skin cancer related mortality. Early metastases are characteristic of melanoma and are an ominous sign, as current therapeutic interventions have little effect on overall survival. The lack of accurate prognostic indicators and effective therapies emphasize the need for a better understanding of the genetic and phenotypic changes in melanoma formation and progression. One such change is the loss of E-cadherin, which normally plays a role in cell-cell adhesion and is thought to be a central feature of epithelial-mesenchymal transition (EMT). Maintenance of E-cadherin in melanoma …

Yale School Of Medicine Facts & Figures 2012-2013, Yale School Of Medicine Office Of Communications

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Medicine@Yale March 2012 Volume 8, Issue 1, Yale School Of Medicine Office Of Communications

Medicine@Yale - development newsletter

Medicine@Yale : advancing biomedical science, education and health care was a print and online newsletter which published news about academics, research and philanthropy for alumni, donors, faculty, students and the general public. It was initially published 6 times a year and then changed to a quarterly schedule. The first issue came out June/Jul. 2005. The final issue was published in May/June 2022, vol. 17, issue 1. Published by Yale School of Medicine, Office of Communications.

Medicine@Yale May 2012 Volume 8, Issue 2, Yale School Of Medicine Office Of Communications

Medicine@Yale - development newsletter

Medicine@Yale : advancing biomedical science, education and health care was a print and online newsletter which published news about academics, research and philanthropy for alumni, donors, faculty, students and the general public. It was initially published 6 times a year and then changed to a quarterly schedule. The first issue came out June/Jul. 2005. The final issue was published in May/June 2022, vol. 17, issue 1. Published by Yale School of Medicine, Office of Communications.

Medicine@Yale September/October 2012 Volume 8, Issue 4, Yale School Of Medicine Office Of Communications

Medicine@Yale - development newsletter

Medicine@Yale : advancing biomedical science, education and health care was a print and online newsletter which published news about academics, research and philanthropy for alumni, donors, faculty, students and the general public. It was initially published 6 times a year and then changed to a quarterly schedule. The first issue came out June/Jul. 2005. The final issue was published in May/June 2022, vol. 17, issue 1. Published by Yale School of Medicine, Office of Communications.

The Influence Of Breastfeeding On Postpartum Weight Retention, Mariam Girguis

Public Health Theses

Background:your words Weight gained during pregnancy and not lost postpartum has been identified as a contributor to increased obesity risk among women of childbearing age.

Objective: To determine the influence of "any" and exclusive breastfeeding duration on postpartum weight retention (PPWR).

Design: Women were selected from the longitudinal Infant Feeding Practices Study II (IFPS II) . All women who reported both their pre-pregnancy weight and at least one postpartum weight were included in the analyses. Multivariate logistic and linear regression models were used to examine the association between "any" and exclusive breastfeeding duration and PPWR at 3 (n=2254), 6 (n=1966), …

Disrupting The Dyad: Effects Of Parenting Stress On Infant Social-­Emotional Development, Anna L. Zonderman

Public Health Theses

BACKGROUND. Social-­emotional development in infancy can be compromised by exposure to violence, parental mental illness and other factors that interfere with a caregiver's ability to anticipate and respond to an infant's needs. Parenting stress may influence social­emotional development in the same way. In the context of disturbances to parental care, stress on the caregiver is known to adversely affect infant social-­emotional development. However, there is limited empirical evidence explicitly examining the impact of parenting stress (as it is measured in this analysis).

OBJECTIVES. To examine the effect of maternal parenting stress on the social-­emotional development of infants born to young, …