Best Selling Books by Jen Wang

A central goal of evolutionary biology is to understand the origin and maintenance of genetic and phenotypic variation in natural populations. Examining cases of adaptive variation, in particular, across different environments provides an opportunity to understand the essential evolutionary forces underlying biological diversification. Color polymorphism is a particularly promising system for the study of adaptive variation, because color patterns provide quantifiable and often dramatic differences within species that are conspicuously affected by natural selection. For my dissertation research, I examined color variation in two species of poison-dart frogs, Dendrobates pumilio and D. granuliferus, to investigate several fundamental questions in phenotypic evolution, including whether color traits are highly constrained in aposematic species, whether genetic isolation allows for the evolution of color polymorphism, and whether variation in conspicuousness evolves to match variation in toxicity. Contrary to prevailing theories, my results demonstrate that color traits are actually highly labile in D. pumilio, that divergence in coloration in D. pumilio led to genetic isolation rather than vice versa, and that conspicuousness is actually negatively associated with toxicity in D. granuliferus. Together, these results challenge some of the major tenets of aposematic theory and support new theories that may prove more appropriate for understanding aposematic evolution in species with environmentally derived toxicity.

Final issue! The Floop Master is revealed, and Cake takes on the rest of the tournament!

"Age-related macular degeneration (AMD) is a leading cause of irreversible blindness among adults, age 60 and older, in developed countries. While oxidative stress is implicated in the pathogenesis of AMD, clinical studies have shown that dietary antioxidants can delay progression of AMD. Currently, there is no FDA-approved treatment for AMD. Therefore, we hypothesized that N-acetylcysteine amide (NACA), a thiol antioxidant, would protect retinal pigment epithelium and impede the progression of retinal degeneration. The goal of this work was to evaluate the efficacy of NACA in preventing retinal pigment epithelial cell and photoreceptor death in AMD models. To achieve this, we used the oxidants tert-butyl hydroperoxide (TBHP) and sodium iodate (NaIO3) in a cell model and an animal model to evaluate the effects of NACA. Our data suggest that pretreatment with NACA reduces the sub-lethal (but not lethal) effects of TBHP in primary cultures of human retinal pigment epithelial cells. NACA significantly improves cell survival when administered prior to and during the occurrence of oxidative damage similar to that observed in the development of dry AMD. In the chemically- induced retinal degeneration animal model, NACA eye drops partially prevented reduction in visual function, as determined from electroretinograms (ERG) recorded 36 hours after NaIO3 injection. Other toxic effects were observed at a later time point after NaIO3 injection: increased lipid peroxidation (as measured by formation of 4-hydroxynonenal, 4-HNE), elevated cysteine levels, and death of photoreceptors resulting in outer nuclear layer thinning. NACA eye drops reversed these toxic effects. In conclusion, this potent antioxidant should continue to be investigated as a treatment for AMD"--Abstract, page iv.

Optically transparent, wide bandgap metal oxide semiconductors are a promising candidate for large-area electronics technologies that require lightweight, temperature-sensitive flexible substrates. Because these thin films retain relatively high carrier mobilities even in an amorphous state, metal oxide-based field effect transistors (FETs) can be processed at near-room temperatures. Compared to amorphous silicon FETs, which are the dominant technology used in display backplanes, metal oxide FETs have been demonstrated with higher charge carrier mobilities, higher current densities, and faster response performance. In this thesis we present a low-temperature (''1000C), scalable, fully lithographic process for top-gate, bottom-contact amorphous zinc indium oxide FETs using parylene, a room-temperature-deposited CVD polymer, as gate dielectric. Electrical characteristics were compared for FETs of varying device dimensions (W, L) using a standard set of extracted device parameters. We show in both simulation and experiment that the FET threshold voltage can be modified by varying the channel thickness alone, without requiring the additional complexity of multiple channel materials or different dopings. The baseline lithographic process was further developed to enable the integration of FETs of different channel thicknesses, and hence threshold voltages, on a single substrate. The availability of FETs with different threshold voltages allows the implementation of enhancement-depletion (E/D) logic circuits that have faster speeds and smaller device areas than single-VT topologies. Using the two-VT lithographic process, we fabricated integrated E/D inverters that operate at VDD as low as 3V with gains u003e 20 and symmetric noise margins ~1.2V. Furthermore, we demonstrated integrated 11-stage and 21-stage E/D ring oscillators that operated rail-to-rail at VDD= 3V and maintained oscillation for VDD as low as 1.7V. These results demonstrate the potential for low VDD metal oxide-based integrated circuits fabricated in a low temperature budget, fully lithographic process for large-area transparent electronics.

Prince Sebastian is looking for a bride or rather, his parents are looking for one for him. Sebastian is too busy hiding his secret life from everyone. At night he puts on daring dresses and takes Paris by storm as the fabulous Lady Crystallia the hottest fashion icon in the world capital of fashion!