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Full-Text Articles in Life Sciences
Effects Of Maternal And Neonatal Hypoxia On The Future Life History Of Daphnia Magna, Rachael Lowman
Effects Of Maternal And Neonatal Hypoxia On The Future Life History Of Daphnia Magna, Rachael Lowman
Undergraduate Honors Theses
Early exposure to hypoxia is related to a variety of physiological and metabolic changes that have lasting effects on organisms’ physiology and life history. We measured the effects of maternal and embryonic mild, intermittent hypoxia on the life history of four clones of microcrustacean Daphnia magna, an emerging model organism for the studies of senescence and longevity. Daphnia individuals were produced parthenogenically, maintained in individual vials, and fed standard algal concentration daily. The cohort consisted of 189 individuals. We measured body size at first reproduction, fecundity (including late-life fecundity peak), offspring sex ratio, and longevity. We found no effect …
An Elevational Gradient In Thermal Tolerance Among Daphnia From Western Maine Lakes, Wheeler Lowell
An Elevational Gradient In Thermal Tolerance Among Daphnia From Western Maine Lakes, Wheeler Lowell
HON 499 Honors Thesis or Creative Project
With climate change threatening biodiversity worldwide, it is important to understand species’ physiological responses to changing thermal environments. This study examined whether thermal tolerance (measured as time to immobilization, Timm) in the zooplankton Daphnia catawba and D. schødleri varied along an elevational gradient in Western Maine. Specimens collected from five lakes were subjected to heat stress trials to look for inter-population variation. Thermal tolerance was strongly correlated with several elevation-driven lake temperature variables, with the percent of variation explained ranging from 13-37%. Daphnia from cooler, high-elevation lakes were more sensitive to elevated temperatures. While latitudinal gradients have been examined extensively, …
Daphnia Pulex: The Mixed Messages Of Mutations , Matthew Randall Bruner
Daphnia Pulex: The Mixed Messages Of Mutations , Matthew Randall Bruner
Theses and Dissertations
While mutations are almost universally considered to be more often deleterious than beneficial, their precise interactions between different populations and individual lines have been largely overlooked. Using mutation accumulation lines of four clones of obligately asexual Daphnia pulex, this research is intended to investigate the degree to which spontaneous mutation would affect fitness-related traits after roughly 100 generations. The expectation was that there would be a visible decrease in juvenile specific growth rate, the surrogate measurement used for fitness, across all four clones due to the deleterious nature of mutation in a selection free environment. Through measuring birth mass in …
Optimizing The Delivery Of A Gfp Gene Via A Biocompatible Nanocarrier In Daphnia And A Chironomid, Alexandra R. Job
Optimizing The Delivery Of A Gfp Gene Via A Biocompatible Nanocarrier In Daphnia And A Chironomid, Alexandra R. Job
Honors Thesis
Current pest control methods impose risks including pest resistance to insecticides, bioaccumulation of the insecticide, and ecosystem impact. There is a need for a better and more sustainable method of pest control in order to protect the environment and the populations reliant on it. Currently, an alternative method of pest control uses RNA interference (RNAi), that exploits heterologous protein expression to disable the insect pest, delivered by the use of nanoparticles. Nanocarriers show great promise in this method of use, but concerns of cytotoxicity, biodegradability, and transfer to off target organisms require careful consideration. This study focuses on optimizing a …
Investigating Mechanisms Of Nanotoxicity Of A Next-Generation Lithium Cobalt Oxide Nanomaterial, Nicholas Joseph Niemuth
Investigating Mechanisms Of Nanotoxicity Of A Next-Generation Lithium Cobalt Oxide Nanomaterial, Nicholas Joseph Niemuth
Theses and Dissertations
Commercial use of engineered nanomaterials (ENMs; materials in the range of 1-100 nm) has grown dramatically since the discovery of the means to observe, characterize, and controllably synthesize these materials at the end of the 20th century. Today, ENMs represent a global market valued in the trillions of dollars, incorporated into products because of the unique properties they confer, including increased strength, catalytic activity, and interactions with light. In this time, ENMs have also grown from relatively simple first-generation materials, such as Au, Ag, and carbon ENMs, to complex next-generation materials incorporating numerous elements into materials with complex secondary structures, …
Effect Of Oxidative Stress On Lifespan And Cellular Survival, Benedicth Onyeka Ukhueduan
Effect Of Oxidative Stress On Lifespan And Cellular Survival, Benedicth Onyeka Ukhueduan
Theses and Dissertations
When cells experience oxidative stress, the integrated stress response (ISR) signaling pathway is activated. One of the first outcomes of such ISR-activated response is to temporarily halt protein synthesis, which aids in cellular recovery. However, if cells cannot recover from the stress, they activate the cell death pathways which kills the affected cells, usually by apoptosis, which can then lead to either acquisition or prevention of diseases depending on the situation. In physiological aging, a compromised stress response is observed as an organism ages, which leads to disrupted homeostasis and elevated risk of disease. Thus, longevity of an organism is …