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Full-Text Articles in Physical Sciences and Mathematics
Characteristics Of Fish Yolk Proteins And A Method For Inducing Vitellogenin, Sean M. Lucey
Characteristics Of Fish Yolk Proteins And A Method For Inducing Vitellogenin, Sean M. Lucey
Masters Theses 1911 - February 2014
Teleosts are one of the most diverse groups of vertebrates. They utilize a wide array of reproductive strategies and tactics to overcome the challenges of the many ecological niches they inhabit. The most common reproductive method for teleosts is oviparity. Oviparous animals lay eggs with little or no embryonic development from the mother. The embryos are supplied with nutrition via yolk. Vitellogenesis is the process of the ovary sequestering yolk. It is regulated by exogenous environmental cues that act on the hypothalamus-pituitary-gonad axis. Through a series of hormonal controls, the liver produces the yolk precursor, vitellogenin. Vitellogenin is secreted by …
Conservation Implications Of A Marbled Salamander, Ambystoma Opacum, Metapopulation Model, Ethan B. Plunkett
Conservation Implications Of A Marbled Salamander, Ambystoma Opacum, Metapopulation Model, Ethan B. Plunkett
Masters Theses 1911 - February 2014
Amphibians are in decline globally and a significantly greater percentage of ambystomatid salamander species are in decline relative to other species; habitat loss contributes significantly to this decline. The goals of this thesis is to better understand extinction risk in a marbled salamander (ambystoma opacum) population and how forestry effects extinction risk. To achieve this goal we first estimated an important life history parameter (Chapter 1) then used a metapopulation model to estimate population viability and determine what aspects of their life history put them most at risk (Chapter 2) and finally predicted extinction risk in response to hypothetical forestry …
Documenting The History Of Oxygen Depletion In Lake St. Croix, Minnesota, Using Chironomidae Remains In The Sedimentary Record, Caitlin E. Stewart
Documenting The History Of Oxygen Depletion In Lake St. Croix, Minnesota, Using Chironomidae Remains In The Sedimentary Record, Caitlin E. Stewart
Masters Theses 1911 - February 2014
Lake St. Croix is a natural impoundment located at the southern end of the St. Croix River. Land use changes since European settlement (c. 1850) have resulted in nutrient runoff, eutrophication, and periodic oxygen depletion in the hypolimnion of Lake St. Croix. Establishing sound lake management practices requires knowledge of historical conditions obtained through paleoecological studies. Remains of non-biting midges (Insecta: Diptera Chironomidae) in lake sediments have been shown to be reliable indicators of past hypolimnetic oxygen conditions. Cores from two sub-basins in the lake were collected in 2006. Midge analysis indicated that shifts in species assemblages correspond to the …