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Life Sciences

University of Massachusetts Amherst

Doctoral Dissertations

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Determining Kinetic Parameters Of Thiamine Degradation In Three Nasa Spaceflight Foods In Thermal Processing And Long-Term Storage And Methods For Analyzing Microstructure And Precipitant Development In Real And Model Wines, Timothy R. Goulette Jul 2019

Determining Kinetic Parameters Of Thiamine Degradation In Three Nasa Spaceflight Foods In Thermal Processing And Long-Term Storage And Methods For Analyzing Microstructure And Precipitant Development In Real And Model Wines, Timothy R. Goulette

Doctoral Dissertations

The current NASA spaceflight food program encompasses a wide variety of commercial and custom-made edible products. These foods are designed to ensure each crewmember receives the Recommended Dietary Allowance (RDA) of vitamins and minerals to maintain adequate health during the entire spaceflight mission. With the desire for long-duration and exploration-class missions, such as the impending mission to Mars, the retention of important nutrients such as labile vitamins in spaceflight foods is critically important. For this reason, multiple studies were conducted to determine the vitamin degradation behavior of thiamine (vitamin B1) within three spaceflight foods which demonstrated both significant …


Epigenetic Regulation Of Genomic Imprinting During Early Mammalian Embryonic Development, Chelsea Marcho Nov 2018

Epigenetic Regulation Of Genomic Imprinting During Early Mammalian Embryonic Development, Chelsea Marcho

Doctoral Dissertations

Mammalian development involves remarkable changes, starting from a single-cell, totipotent zygote and ending with a developed organism comprised of diverse cells types with distinct morphologies, structures, and functions. Within three days of murine development, the two parental genomes merge into a single nucleus, begin zygotic gene expression, undergo epigenetic remodeling, and make the first lineage decisions. Diversity in cell-types is possible even though cells share the same genome. This diversity is achieved by the tight regulation of differential transcriptional programs. There are many ways these transcriptional programs can be initiated. Epigenetic alterations to the genome can drive transcriptional changes. Epigenetic …


Distribution And Population Dynamics Of Ungulates In The Mongolian Gobi, Buuveibaatar Bayarbaatar Nov 2016

Distribution And Population Dynamics Of Ungulates In The Mongolian Gobi, Buuveibaatar Bayarbaatar

Doctoral Dissertations

The Mongolian Gobi is one of the most spectacular and important regions in Central Asia, comprising the largest area of intact grassland in the world. In recent years, a growing human population, expanding exploitation of natural resources, and the development of infrastructure in the region place increasing pressure on these species and their habitats. This dissertation has focused on three species of ungulates such as Mongolian saiga (Saiga tatarica mongolica) in western Mongolia, and Asiatic wild ass (Equus hemionus), and goitered gazelle (Gazella subgutturosa) in Southern Gobi. The study on endangered saiga antelope in …


Effects Of Adolescent Alcohol Binge Drinking On Prefrontal Myelin, Wanette M. Vargas-Rodriguez Nov 2016

Effects Of Adolescent Alcohol Binge Drinking On Prefrontal Myelin, Wanette M. Vargas-Rodriguez

Doctoral Dissertations

Alcohol binge drinking is highly prevalent in teenagers and is associated with various harmful health effects and social problems. During adolescence, brain regions such as the prefrontal cortex (PFC) are still undergoing active development, characterized by increases in white matter volume. While the morphological details and the cellular and molecular sequences governing adolescent white matter development are not fully known, it is known that this development process is sensitive and can be disrupted. Although consumption of alcohol in a binge drinking pattern has been linked to lower white matter integrity in humans, it is important to determine if alcohol is …


Evolvability Of The Skull: A Study Of Genetic Basis And Integration In The Teleost Craniofacial Skeleton, Yinan Hu Mar 2016

Evolvability Of The Skull: A Study Of Genetic Basis And Integration In The Teleost Craniofacial Skeleton, Yinan Hu

Doctoral Dissertations

As the field of evolutionary biology pivots away from a gene-centric view of how adaptive evolution proceeds, renewed emphasis is placed on the origin of phenotypic variation. Understanding the developmental processes that underlie the production of novel traits, and how they might influence evolvability, is considered a primary goal in the on-going “extended evolutionary synthesis”. The following dissertation explores these questions in the context of adaptive radiations in fish, with a focus on morphological variation in the craniofacial skeleton. Specifically, the first chapter investigates the genetic and developmental basis of shape (co-)variation in the feeding apparatus of African cichlid fishes, …