Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Earth and Planetary Sciences, 1980. / Microfiche copy available in Archives and Science. / Vita. / Includes bibliographies. / by Alan Dana Chave. / Ph.D.

Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Earth and Planetary Sciences, 1980. / Microfiche copy available in Archives and Science. / Vita. / Bibliography : leaves 122-129. / by Dean Howard Roemmich. / Ph.D.

Demographic changes, through immigration/emigration (or death) can affect the social and community structure of a population. This study reports on the effects of demographic changes following 2 intense hurricanes on two sympatric delphinid species: Atlantic bottlenose dolphins, Tursiops truncatus, and Atlantic spotted dolphins Stenella frontalis. Thirty percent of the bottlenose population was lost after the hurricanes, with an influx of roughly the same number of immigrants. The stable community split into two cohesive units. Preferences in association in relation to reproductive status and sex remained. Immigrants assimilated well into the population, especially males. There is a conflict of interest between resident males and females in accepting immigrants and often females find more resistance than males. Long-term analysis of spotted dolphins revealed a community structure defined by long-term site fidelity, natal philopatry of both sexes and three social clusters. / Female associations were influenced by reproductive status and social familiarity within clusters. Males formed long-term alliances and shorter-term coalitions. Some movement between clusters occurred. Alliance formation crystallized in adulthood. Mating strategies and sex were the primary factors shaping social structure. Thirty-six percent of the spotted dolphin population was lost after the hurricanes with no influx of immigrants. The spotted dolphin community differed little from long-term analysis, including definitive social clusters and sex preferences. Social cohesion increased within units and across age classes. Some juveniles had associations of alliance level. Loss of individuals resulted in subtle changes in social structure. Interspecies associations reveal striking differences in association patterns between species. Group sizes and re-sightings of spotted dolphins were larger than for bottlenose dolphins, particularly for aggressive encounters. / Male alliances and coalitions were prevalent for spotted dolphins, but not for bottlenose dolphins. After the hurricanes lower re-sighting and group sizes for spotted dolphin males and less aggressive behavior documented, indicates a re-structuring period of relationships between the species. This study shows that environmental variations may alter the structure of mammal societies through demographic upheaval and survival of populations may depend on their social structure and the social adaptability of the species. / by Cindy Rogers Elliser. / Thesis (Ph.D.)--Florida Atlantic University, 2010. / Includes bibliography. / Electronic reproduction. Boca Raton, Fla., 2010. Mode of access: World Wide Web.

Recently, there has been an increase in marine mammal mortalities, most commonly Atlantic bottlenose dolphins, Tursiops truncatus, which is an alarming indication of the health status of the marine ecosystem. Studies have demonstrated that some free-ranging dolphins exhibit a suppressed immune system possibly because of exposure to contaminants or infectious microorganisms. However, this research has been limited due to a lack of commercially available marine-specific antibodies. Therefore, the first chapter of this thesis aims to identify cross-reactive terrestrial-specific antibodies that could be used to phenotype and compare the immune cell populations of dolphins under human care and free-ranging dolphins. The second chapter aims to utilize terrestrial-specific growth factors and dendritic cell (DC) surface markers to generate, characterize, and compare ex vivo DCs from peripheral blood mononuclear cells (PBMCs) of dolphins under human care and free-ranging dolphins. In summary, I have identified differences within the PBMCs and ex vivo generated DCs of dolphins under human care and free-ranging dolphins that could potentially shed light on the impact of environmental contaminants and infectious microorganisms on immune cells which could lead to increased morbidity and mortality. / Includes bibliography. / Dissertation (Ph.D.)--Florida Atlantic University, 2015. / FAU Electronic Theses and Dissertations Collection

Thesis (S.M.)--Joint Program in Physical Oceanography (Massachusetts Institute of Technology, Dept. of Earth, Atmospheric, and Planetary Sciences and the Woods Hole Oceanographic Institution), 2000. / Includes bibliographical references (p. 65-67). / With Lagrangian and hydrographic data taken in the deep Brazil Basin, we identify several submesoscale coherent vortices (SCVs). These features contrast with SCV paradigms in that float data indicate approximately equal populations of cyclonic and anticyclonic vortices, and hydrographic data suggest that roughly half exhibit the convex lens shape generally associated with SCVs, while half are instead shaped like a concave lens, with isopycnal surfaces pinched together. There is some evidence that the vortex cores may be enriched in warm, salty North Atlantic Deep Water, suggesting formation in the north or northwest regions of the basin. Data is available from 153 floats which were ballasted for 2500 and 4000 db pressures. They tracked 34 eddies, which are believed to be roughly 30 km in diameter, and rotate with apparent periods of about 30 days. Many floats experienced formation or entrainment events, and destruction or detrainment events, near seamounts. / by Patricia Kassis. / S.M.

Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Meteorology, 1979. / Microfiche copy available in Archives and Science. / Bibliography : leaves 81-83. / by Affonso da Silveira Mascarenhas, Jr. / M.S.

Thesis (Ph. D.)--Joint Program in Physical Oceanography (Massachusetts Institute of Technology, Dept. of Earth, Atmospheric, and Planetary Sciences; and the Woods Hole Oceanographic Institution), 2010. / Cataloged from PDF version of thesis. / Includes bibliographical references (p. 165-174). / The variability in the DWBC, its connection to the forcing in the northern North Atlantic and interaction with the Gulf Stream were explored from a combination of remote sensing and in-situ measurements in the western North Atlantic. Using satellite altimetry and Sea Surface Temperature (SST) we found evidence of the relation between changes in the Gulf Stream path and the variability in the temperature and velocity fields in the Slope Water. This relation was such that southward shifts of the main axis of the Gulf Stream were preceded by cold temperature anomalies and intensification of the southwestward flow. The analysis of 5.5 years of moored CTD and horizontal velocity data in the DWBC at 69 0W recorded during the period 2002-2008, showed that the variability along the DWBC is linked to changes in the dense water formation regions. The evolution of potential vorticity (PV) at the mooring site, characterized by a transition from deep to upper Labrador Sea Water (LSW), was similar to that observed in the Labrador Sea 6 to 9 years earlier, and imply spreading rates for the LSW that varied over time from 1.5 to 2.5cm/s. The time dependence of the spreading rates was in good agreement with changes in the strength of the DWBC at the mooring site. The evolution of the DWBC transport was explored in more detail from a 5- element moored array, also at 69'W. The results, for the period of 2004-2008, were consistent with the single mooring analysis. The variability measured from the array showed that upper, intermediate and deep water mass layers expand and contract at each other's expense, leading to alternating positive and negative PV anomalies at the upper-LSW, deep-LSW and Overflow Water (OW). Larger DWBC transports were associated with enhanced presence of recently ventilated upper-LSW and OW, rather than deep-LSW. The relative contribution of the different water masses to the observed circulation was investigated by inverting individual PV anomalies isolated from the observations. We found that changes in the depth-integrated circulation were mostly driven by changes in the OW. / by Beatriz Peña-Molino. / Ph.D.

Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Meteorology and Physical Oceanography, 1981. / Microfiche copy available in Archives and Science. / Bibliography: leaves 53-54. / by James Che-Ming Chung. / M.S.

Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Meteorology and Physical Oceanography, 1982. / Microfiche copy available in Archives and Science. / Vita. / Bibliography: leaves 221-225. / by Ping-Tung Peter Shaw. / Ph.D.

Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Meteorology and Physical Oceanography, 1981. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND LINDGREN. / Vita. / Bibliography: leaves 255-261. / by Neal Robert Pettigrew. / Ph.D.