Tuna fishery is an important activity worldwide. In the
eastern Pacific Ocean the effort applied by the Pacific Ocean
fleet to catch tuna fish is considerable. The eastern Pacific
tuna fleet harvests throughout the oceans and captures an
important fraction of this resource. For instance, in 1980 the
total catch...
This investigation explored the use of microcosms as a tool for
studying the dynamics of tropical aquaculture ponds. The potential use
of rabbit excreta as a pond fertilizer in integrated farming systems was
also investigated.
Twelve insulated fiber glass tanks were utilized as microcosms to
simulate earthen ponds. Seven hand-sexed...
Sex differentiation in fish is a labile process that allows sex inversion in several species. The inherent capacity of fish germ cells to differentiate into oocytes or spermatocytes constitutes a key factor allowing for functional sex inversion. This thesis set out to determine the mechanism involved in steroid-induced sex differentiation...
This dissertation presents the results of statistical analyses of large climate datasets from two time intervals – the 20th century instrumental record and the proxy record of the last deglaciation – in order to understand the forcings and mechanisms of past climate variability.
A longstanding question in climate dynamics concerns...
This dissertation presents results from three studies that address major scientific questions in glacial geology and paleoclimatology for the late Pleistocene and Holocene using relatively new geochemical and statistical techniques. Each of the studies attempts to answer a longstanding question in the respective field using geochemical or statistical methods that...
Halogenated organic compounds have had widespread and massive applications in industry, agriculture, and private households, for example, as degreasing solvents, flame retardants and in polymer production. They are released to the environment through both anthropogenic and natural sources. The most common chlorinated solvents present as contaminants include tetrachloroethene (PCE, perchloroethene)...
This thesis presents the results from Monte Carlo calculations on classical vector spins in
face-centered-cubic (FCC) lattices. The goal of the study was to understand the effect of
interlayer coupling, dilution of magnetic atoms in the lattice, and symmetry-changing
strain.
Experimental work by T. M. Giebultowicz et al. and J....
The results presented in this dissertation address a number of questions regarding late Pleistocene and Holocene ice-sheet and climate interactions, spanning disciplines involving paleoclimatology and atmospheric science. These studies use various techniques in geochemistry, climate modeling, and ice-sheet modeling to address ice- sheet response to climate and the attendant interactions...
The last deglaciation of the Scandinavian Ice Sheet (SIS) from ∼21,000 to 13,000 yr ago is well-constrained by several hundred ¹⁰Be and ¹⁴C ages. The subsequent retreat history, however, is established primarily from minimum-limiting ¹⁴C ages and incomplete Baltic-Sea varve records, leaving a substantial fraction of final SIS retreat history...