All forms of energy generation can have intensive or extensive land use requirements, causing habitat and biodiversity loss in sensitive and diverse ecosystems globally. With the rapid transformation and growth of the energy sector in countries worldwide, understanding the impacts of past practices and charting the trajectory of future development projects is imperative for preventing negative environmental consequences. This dissertation contributes modeling strategies for integrating environmental impacts in renewable energy planning processes and spatially-explicit empirical methods for identifying and quantifying land use and land cover impacts related to renewable energy development.

To explore land use and energy conflicts in a jurisdiction that is in the midst of a large-scale low-carbon energy transition, I ask the following: (1) is it possible to meet California's ambitious renewable energy targets without using high conservation-value land? (2) what are the system costs of low-impact renewable energy development? I find that while trade-offs between conservation value and renewable resource quality exist, restricting development to low-impact land is not only possible, but incurs only negligible economic cost increases. Given this possibility, I use California as a case study to identify decision-making opportunities in energy planning processes for integrating conservation and land use values and avoiding conservation-climate conflicts.

Extending the spatial methods developed for California to countries in Africa that are planning renewable energy expansion, I ask, what is the potential for low-environmental-impact, socially-responsible, and cost-effective development of wind and solar energy in emerging economies in Africa? Using a multi-criteria analysis approach, I find that "no-regrets'' options---specifically areas that are low-cost, low-environmental impact, and highly accessible--exist such that significant fractions of demand can be quickly served with low-impact resources without large additional cost.

Despite the magnitude and pace of hydropower expansion in highly biodiverse aquatic and terrestrial ecosystems in Southeast Asia, Africa, and Latin America, the potential indirect land use and land cover change resulting from hydropower development is poorly understood. To fill this gap, I ask, what are the indirect deforestation and land use impacts of utility-scale hydropower development in the Brazilian Amazon? Do siting choices and pre-existing land use and land cover affect the extent of the impact? Using scalable remote sensing and spatial econometric methods for causal inference, I find a 11-59% increase in indirect deforestation due to hydropower development. These findings can contribute to estimates of potential future terrestrial impacts from the hundreds of hydropower plants planned and proposed in relatively intact areas of the Brazilian Amazon.

Clinical parameters for dental whitening such as peroxide concentration and treatment time have been empirically derived. However, limited quantitative analyses examine reactivity of hydrogen peroxide on in vivo tooth stains under various catalytic settings. The wide range of possible activators and stains are challenging in creating a standardized tooth model to isolate various effects for clinical applications. This study uses three model systems to determine the effects of heat, light, metal catalysts, and pH on peroxide bleaching. By first using a model chemical stain, alkaline pH levels (7.4), 35°C heat treatment, and 490nm light activation were optimal for increasing overall bleaching efficacy. When the same conditions were applied to bleaching stained bovine teeth using liquid peroxide, only 35°C heat treatment showed catalytic effect, increasing overall luminosity and decreasing yellowness. A final evaluation of the activation parameters on teeth treated with commercially used gel peroxides revealed positive catalytic activity for heat alone. These results, in conjunction with future clinical studies, can provide the basis for optimizing clinical whitening parameters and ultimately control peroxide reactivity to enhance bleaching efficacy while minimizing undesired side-effects.

There is growing recognition that language and executive function may independently affect numerical cognition, but few studies have examined all three constructs simultaneously. In two studies, I examined the relationship between language and math while considering executive function in emergent bilingual kindergartners in mainstream English classes and Mandarin immersion classes.

The 11 measures—three for language, four for executive function, and four for mathematics—used in this dissertation were adequately reliable and valid for children attending typical English instruction classes. However, the measures showed a distinct structural pattern for children in the Mandarin immersion classes. Adjustments were therefore made for the studies in this dissertation. Implications of such differences were also discussed.

In Study 1, I investigated the relationship between linguistic, executive function, and mathematical skills in predominantly low-SES emergent bilingual kindergartners. Using structural equation modeling, I showed that language has a direct effect on executive function, and that executive function, in turn, has a direct effect on overall mathematics such that the effect of language proficiency on mathematics appeared to be mediated through its effect on executive function.

In Study 2, I examined how learning a language with a base-10 transparent number system may or may not influence kindergartners’ different mathematics performance. Using multiple regressions supplemented by Bayesian analyses, I demonstrated that being exposed to the base-10 transparent Chinese number system in Mandarin immersion classes is associated with higher performance in counting, comparing magnitude, and estimating the position of a number on a number line even after accounting for children’s executive function skills.

Findings from this dissertation underscore the importance of considering interrelated constructs in cognitive research, as the story that emerged may broaden our understanding of the mechanism of human cognition. Furthermore, they tentatively show that monolingual children may be able to benefit from dual-language immersion programs beyond learning a second language.

Aging individuals can develop generalized, exquisitely-pruritic, eczematous eruptions of uncertain etiology that can be therapeutically-refractory and life-altering. Limited information exists in the literature to guide clinicians in the diagnosis and management of such patients. It is suggested that in approximately 40% of such patients a known cause for their chronic pruritic eruptions cannot be identified. In this report we will refer to this subgroup of patients as having idiopathic chronic eczematous eruption of aging (CEEA). Idiopathic CEEA must be distinguished from other established eczematous dermatoses. Idiopathic CEEA patients often require long-term systemic immunosuppressive drugs to make living bearable. Elder-onset atopic dermatitis is the most difficult of the known dermatoses to distinguish from idiopathic CEEA. Because of their clinical similarities we questioned whether dupilumab (Dupixent®), the first FDA-approved biologic for atopic dermatitis, might be valuable in the management of idiopathic CEEA. We report the case of an elderly man with idiopathic CEEA of four-years’ duration who had a complete clinical response to the initiation of treatment with dupilumab. This case is presented to stimulate more discussion and systematic study of a possible role for dupilumab in otherwise-refractory idiopathic CEEA patients. We also propose a set of diagnostic criteria for idiopathic CEEA.