Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 7 of 7 for “"temperature-dependent sex determination"”.
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Sex Determination And Differentiation In The Common Snapping Turtle - A Reptile With Temperature-Dependent Sex Determination
<p>Temperature-dependent sex determination (TSD) was first discovered in an African lizard over 40 years ago. TSD has since been shown to be exhibited by many vertebrates including some fish and amphibians, numerous lizards, turtles, and all crocodilians studied to date. Although numerous questions …
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Incubators for Species which Exhibit Temperature-Dependent Sex Determination: Application to Hawksbill Sea Turtles in Rising Ambient Temperatures
As global ambient temperatures continue to rise, with the highest recorded annual averages since 1850 being within the last ten years, problems emerge for species exhibiting temperature-dependent sex determination. This is the process by which the sex of an animal’s embryo is determined based on …
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The Evolution of Sex Determination and the DMRT1 Gene in the Japanese Gecko (Gekko japonicus)
There are different sex-determining mechanisms in our environment, which are separated into two groups known as genotypic sex determination (GSD) and environmental sex determination. The most well-known mechanism in the ESD group is temperature-dependent sex determination (TSD). In this study, the …
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Reproductive Parameters of Nesting <em>Caretta caretta</em> on Georgia's Barrier Islands
… increase hatching success. Recent research on temperature-dependent sex determination, population genetics, and migratory movement patterns in other species support the view that further research in Georgia is required to understand the contribution of these smaller nesting colonies to the …
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Individual and Interactive Impacts of Mercury and Agriculture on Reproduction in a Freshwater Turtle, Chelydra serpentina
… excavation, and the importance of incubation temperature on survival and offspring phenotype. These same disturbed sites are often contaminated by pollutants and turtles can incorporate high levels of pollutants into their eggs which negatively impact hatch success. For my M.S. research, I …
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A Method for Detecting Nesting Activity, Thermal Implications of Different Nesting Strategies, and Activity Patterns of Ornate Box Turtles (Terrapene Ornata)
… that may have important implications for the sex ratios of this temperature-dependent species. Data loggers placed into nest cavities revealed that underground nesting did not affect mean incubation temperatures, but the behavior reduced thermal variation of incubation temperatures. Automated …
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As global ambient temperatures continue to rise, with the highest recorded annual averages since 1850 being within the last ten years, problems emerge for species exhibiting temperature-dependent sex determination. This is the process by which the sex of an animal’s embryo is determined based on the temperature of environment in which it is incubated, which can result in skewed sex ratios within a population like in the case of the critically endangered Hawksbill Sea Turtles (Eretmochelys imbricata). Reportedly, 85-95% of Hawksbills sampled in the wild are currently female [3]. This sex-imbalance can negatively impact the species’ ability to procreate, leading to the potential for extinction. Currently, no viable, long-term solutions exist to effectively and safely cool sea turtle eggs while still keeping them within their natural habitat. This research proposes the creation of sea turtle egg incubators designed to achieve a temperature range that will produce a higher percentage of male hatchlings to help rectify this imbalance in habitats heavily affected by climate change. These incubators are designed to be affordable, easy to build and, most importantly, safe for the sea turtle eggs. Three-month-long temperature trials for the incubator were conducted in Jamaica with conservationist community partners at Oracabessa Bay Sea Turtle Project. Results showed that this incubator is not only easy to manufacture and use, but that it successfully regulates the temperature range in favor of more male hatchlings, while also increasing the emergence rate of the hatchlings from 70% in natural nests to over 80%. During one of the hottest months in Jamaica, the incubator, deployed without water changes, doubled the predicted percentage of males produced by natural nests. When provided with cool water changes the incubator quintupled this value. Throughout the months of August to October, the incubator achieved a temperature range that is predicted to produce 85-99% male hatchlings, thus counteracting the feminization phenomenon occurring in nature.
Foams, widely used in packaging, insulation, protective gear, and medical implants, are versatile materials but mechanically inefficient due to their bending-dominated microstructure, leading to an exponential loss of stiffness and strength at low relative densities. Architected materials address …