• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 50
  • 14
  • 6
  • 3
  • 3
  • 3
  • 3
  • 3
  • 3
  • 3
  • 1
  • 1
  • 1
  • 1
  • 1
  • Tagged with
  • 88
  • 88
  • 21
  • 12
  • 10
  • 6
  • 6
  • 5
  • 5
  • 4
  • 4
  • 4
  • 4
  • 4
  • 4
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Visualizing Geospatial Uncertainty in Marine Animal Tracks

Mostafi, Maswood Hasan 12 April 2011 (has links)
Electronically collected animal movement data has been analyzed either statistically or visually using generic geographical information systems. The area of statistical analysis in this field has made progress over the last decade. However, visualizing the movement and behavior remains an open research problem. We have designed and implemented an interactive visualization system, MarineVis, to visualize geospatial uncertainty in the trajectories of marine animals. Using MarineVis, researchers are able to access, analyze and visualize marine animal data and oceanographic data with a variety of approaches. In this thesis, we discuss the MarineVis design structure, rendering techniques, and other visualization techniques which are used by existing software such as IDV to which we compare and contrast the visualization features of our system. Finally, directions of future work related to MarineVis are proposed which will inspire others to further study the challenging but amazingly interesting and exciting research field of marine visualization. / Marine animal movement is a fundamental yet poorly understood process. One of the reasons is because our understanding of movement is affected by the measurement error during the observation and process noise. Differentiating real movement behavior from observation error in data remains difficult and challenging. Methods that acknowledge uncertainty in movement pathways when estimating constantly changing animal movement have been lacking until this time. However with the arrival of state-space models, this problem is partially solved as SSMs acknowledge this problem by allowing unobservable true states to be estimated from data observed with errors which arise from imprecise observations. State-space models use Markov Chain Monte Carlo methods which generate samples from a distribution by constructing a Markov Chain where the current state only depends on the immediately preceding state. The task of fitting SSMs to data is challenging and requires large computational effort and expertise in statistics. With the arrival of the WinBUGs software, this formidable task becomes relatively easy. Though using the WinBUGs software researchers try to visualize the tracks and behaviors, new problems appear. One of the problems is that when marine animals come back to certain places or animals' tracks cross each other several times, the tracks become cluttered and users are not able to understand the direction. Another problem of visualizing the confidence intervals generated using SSMs is that images generated using other systems are static in nature and therefore lack interactivity. Information becomes cluttered when too much data appear. Users are not able to differentiate tracks, confidence intervals or the information they would like to visualize. Acknowledging these, we have designed and implemented an interactive visualization system, MarineVis, where these problems are overcome. Using our system the confidence intervals generated using the SSMs, can be visualized more clearly and the direction of the turtle tracks can be understood easily. Our system does not occlude the underlying terrain as much because the glyphs are localized at the sample points rather than being spread out around the entire path. Our system encodes both direction and position rather than just position. Users can interactively limit the view of data points as a subset of available data points on a path, in clustered regions, to reduce congestion, and can animate the progression of the animal along its trajectory which is absent in existing approaches. All these results are visualized over NASA World Wind maps that facilitates the understanding of the tracks.
12

If Descartes swam with dolphins : the framing and consumption of marine animals in contemporary Australian tourism /

Jarvis, Christina Harwood. January 2000 (has links)
Thesis (Ph.D.)--University of Melbourne, Dept. of Geography and Environmental Studies, 2000. / Typescript (photocopy). Includes bibliographical references (leaves 273-304).
13

Reproductive ecology and characterization of population genetic structure of Fucus vesiculosus linnaeus in the northwestern Atlantic /

Muhlin, Jessica F., January 2007 (has links) (PDF)
Thesis (Ph.D.) in Marine Biology--University of Maine, 2007. / Includes vita. Includes bibliographical references (leaves 104-115).
14

Multi-view, broadband, acoustic classification of marine animals

Roberts, Paul L. D. January 2009 (has links) (PDF)
Thesis (Ph. D.)--University of California, San Diego, 2009. / Title from first page of PDF file (viewed June 16, 2009). Available via ProQuest Digital Dissertations. Vita. Includes bibliographical references (p. 141-155).
15

Body size and metabolic rate in the animal kingdom, with special regard to the marine micro-fauna

Zeuthen, E. January 1947 (has links)
Thesis--Copenhagen. / Bibliography: p. 158-161.
16

A survey of the marine nematodes of Chesapeake Bay, Maryland

Timm, Richard W., January 1954 (has links)
Thesis--Catholic University of America. / Bibliography: p. 67-70.
17

The benthic macrofauna of the mainland shelf of Southern California

Jones, Gilbert Fred. January 1973 (has links)
Thesis (Ph. D.)--University of Southern California, 1967. / Photocopy of: Los Angeles : University of Southern California, 1967. Includes bibliographical references (leaves 577-592).
18

Marine paleoecology of the Fivemile Member of the Hinton Formation, Upper Mississippian, West Virginia and Virginia

Cawthern, Thomas R. January 2007 (has links)
Thesis (M.S.)--West Virginia University, 2007. / Title from document title page. Document formatted into pages; contains x, 107 p. : ill. (some col.), maps (some col.). Includes abstract. Includes bibliographical references (p. 98-104).
19

Marine paleoecology of the Eads Mill Member, Hinton Formation, Upper Mississippian, West Virginia and Virginia

Vance, Timothy January 2007 (has links)
Thesis (M.S.)--West Virginia University, 2007. / Title from document title page. Document formatted into pages; contains x, 80 p. : ill. (some col.), maps (part col.). Includes abstract. Includes bibliographical references (p. 71-75).
20

Distribution of Clostridium botulinum type E in fish, shellfish and the marine environment of the Pacific Northwest, and protein patterns of the toxigenic and non-toxigenic stains

Craig, James Morrison 07 August 1969 (has links)
Interest in the distribution of Clostridium botulinum type E was heightened by the sudden outbreak of human botulism from smoked whitefish chubs and canned tuna fish in 1963. The question arose as to how widely the organism is distributed among fish and shellfish in the Northwest and what potential hazard exists for the consumer of fish products. This sporeforming anaerobic orgnism is heat sensitive and had eluded detection in other surveys where heat shock had been used to eliminate non sporeforming contaminants. More recent study using other techniques than heat to facilitate recovery has shown this organism to be widespread, especially in the marine environment. This study was undertaken to find the incidence and distribution of C. botulinum in the marine organisms and environment of the Pacific Northwest and the food products derived therefrom. All species of fish were examined by incubating the gills and viscera individually in tryptone-peptone-glucose medium anaerobically at 28 C for four days and testing the culture filtrate for mouse toxicity by intraperitoneal injection. Toxic filtrates were typed by retesting them in mice protected by specific botulinal antitoxin of type A, B, E, or F. Among salmonid fish the proportions of specimens of each species yielding toxic filtrates were as follows. Sockeye salmon from the Columbia River, 14 of 59 (23.7%); Chinook salmon from the Columbia River, 19 of 106 (18.0%); Chinook salmon from the Pacific Ocean, 1 of 18 (5,6%); Coho salmon from the Columbia River, 10 of 19 (34.4%); Coho salmon from the Pacific Ocean, 13 of 186 (7.0%); Steelhead trout from the Alsea River, 7 of 37 (19.0%). About one-third of the toxic cultural filtrates were successfully typed and proven to contain botulinal toxin. Most of them proved to be type E toxin but 3 were type A, 3 were type B and one, a comparatively new type, type F, was isolated from a Sockeye salmon in the Columbia River. Pure cultures of Clostridium botulinum type E were isolated from 18 specimens and one specimen yielded a pure culture of type F from a sockeye salmon. This was the second time this type had been isolated. In all of the experimental groups the proportion of fish producing toxigenic cultures was significantly higher in those taken in the two rivers than those of the same species taken from the ocean waters. "Bottom fish" represented by Cod, Sole, Grouper and members of the Sebastodes group were also tested in the manner described above. The number of specimens yielding toxic filtrates were 28 of 157 (17.8%). When grouped according to location at which the fish were caught, those near the mouth of the Columbia River produced a greater percentage of toxic filtrates than did those caught off the open shore line. The results were as follows: Bottom fish from Astoria, 23 of 70 (32.8%), Botton fish from Coos Bay, 5 of 87 (5.6%). Sturgeon specimens produced 3 of 24 (12.5%) toxic filtrates. Most of the species contained type E; however, one type A and one type B were found on typing, with about one-third of the toxic filtrates being successfully typed. Environmental swab samples from the "deep sea" fillet processing plants produced 3 of 39 (7.7%) toxic filtrates. None of the 53 samples taken in the salmon processing plants produced toxic filtrates. Shellfish were collected along the ocean beach and in the estuaries. Three to five shellfish were combined into a single specimen and treated as described. All shellfish obtained from the estuaries demonstrated a higher percentage of toxic filtrates than those obtained from the ocean beach. The results were as follows: Razor clams, 11 of 75 (14.6%), Cockle clams, 12 of 15 (80.0%); Softshell clams, 8 of 12 (66.4%); Littleneck clams, 4 of 11(36.2%); Horseneck clams, 1 of 3 (33.3%); Oysters, 6 of 19 (31.6%); Dungeness crabs, 17 of 24 (71%). Only the razor clams were collected exclusively from the ocean beach. Loss of toxicity on holding mixed cultures at -15 C while awaiting typing was a continual problem. This accounts for only one-third of toxic filtrates being successfully typed. Electrophoretic analysis of the total bacterial proteins was carried out on cell sonicates and cell free culture filtrates by first growing cells for four days at 28 C anaerobically. The cells were separated, washed and disrupted with ultrasonic energy. The cell free culture filtrate was concentrated 10 fold by dialysis against polyethylene glycol 4000. Both the toxigenic organisms and the toxic filtrate demonstrated an extra common protein band in the upper third of the electrophoretic pattern not present in the nontoxic spectra. This band might represent the type E toxin. Differences could also be noted in the number of protein bands in the lower third of the patterns in different nontoxigenic strains and also when the toxigenic and nontoxigenic strains were compared. This could suggest an association with a phage in the toxigenic cultures. / Graduation date: 1970

Page generated in 0.0707 seconds