Vertical-cavity surface-emitting lasers (VCSELs) have a long history of development in GaAs-based and InP-based systems, however III-nitride VCSELs research is still in its infancy. Yet, over the past several years we have made dramatic improvements in the lasing characteristics of these highly complex devices. Specifically, we have reduced the threshold current density from ~100 kA/cm2 to ~3 kA/cm2, while simultaneously increasing the output power from ~10 µW to ~550 µW. These developments have primarily come about by focusing on the aperture design and intracavity contact design for flip-chip dual dielectric DBR III-nitride VCSELs. We have carried out a number of studies developing an Al ion implanted aperture (IIA) and photoelectrochemically etched aperture (PECA), while simultaneously improving the quality of tin-doped indium oxide (ITO) intracavity contacts, and demonstrating the first III-nitride VCSEL with an n-GaN tunnel junction intracavity contact. Beyond these most notable research fronts, we have analyzed numerous other parameters, including epitaxial growth, flip-chip bonding, substrate removal, and more, bringing further improvement to III-nitride VCSEL performance and yield. This thesis aims to give a comprehensive discussion of the relevant underlying concepts for nonpolar VCSELs, while detailing our specific experimental advances. In Section 1, we give an overview of the applications of VCSELs generally, before describing some of the potential applications for III-nitride VCSELs. This is followed by a summary of the different material systems used to fabricate VCSELs, before going into detail on the basic design principles for developing III-nitride VCSELs. In Section 2, we outline the basic process and geometry for fabricating flip-chip nonpolar VCSELs with different aperture and intracavity contact designs. Finally, in Section 3 and 4, we delve into the experimental results achieved in the last several years, beginning with a discussion on the epitaxial growth developments. In Section 4, we discuss the most noteworthy accomplishments related to the nonpolar VCSELs structural design, such as different aperture and intracavity contact developments. Overall, this thesis is focused on the nonpolar VCSEL, however our hope is that many of the underlying insights will be of great use for the III-nitride VCSELs community as a whole. Throughout this report, we have taken great effort to highlight the future research fronts that would advance the field of III-nitride VCSELs generally, with the goal of illuminating the path forward for achieving efficient CW operating III-nitride VCSELs.

Glutamatergic synapses are the main excitatory synapses in the mammalian central nervous system. The assembly and regulation of these highly organized and asymmetric junctions requires extensive molecular signaling mechanisms. Although thousands of components and interactions within the synapse have been identified, the signaling logic that governs their assembly has remained elusive. We show that a conserved cell polarity signaling protein, Lgl1, is localized in the postsynaptic density. Conditional knockout of Lgl1 in hippocampal pyramidal neurons at postnatal day 7

resulted in increased synapse numbers, altered synaptic ultrastructure, altered compositions of synaptic proteins, and reduced AMPA/NMDA ratio. Conditional Lgl1 deletion from adult mice also produces synaptic phenotypes similar to what is observed in the deletion at postnatal day 7. Lgl1 and atypical Protein Kinase C mutually inhibit each other in apical-basal polarity signaling. We found that a double conditional knockout of both isoforms of atypical PKCs in hippocampal neurons at postnatal day 7 lead to changes in synaptic ultrastructure at postnatal day 14, but not synapse number. Reduction of synapse number was observed in adulthood, suggesting a role for aPKC in the maintenance of synapses rather than their initial formation. Conditional deletions of Lgl1 or atypical PKCs lead to deficits in novel object recognition and social interaction. Triple cKO of Lgl1 and atyptical PKCs restores synapse number and some of the behavioral functions, such as open field and novel object recognition, but not social behavior. The phenotypes observed following conditional deletion of Lgl1 or aPKC are consistent with their opposing roles in apical-basal polarity and their influence on other pathways such as the planar cell polarity pathway and cellular adhesion. Lgl1 is one of the genes commonly deleted in a severe but poorly known behavioral disorder, Smith-Magenis Syndrome (SMS), which is often diagnosed with autism. Lgl1+/- animals show increased synapse numbers, deficits in social interaction, and stereotyped repetitive behavior. Furthermore, three previously characterized NMDA antagonists can rescue social interaction in Lgl1+/- animals. Therefore, deletion of Lgl1 may contribute to neuropsychiatric symptoms in SMS and provides insight into cellular pathways that may underlie the behavioral phenotypes that are observed in the syndrome.

This dissertation presents a study of a heterostructure composed of room temperature magnetoelectric multiferroic BiFeO₃ and ferromagnetic Co₉₀Fe₁₀, with specific interest in understanding the interfacial coupling mechanisms in this system and establishing the electric field control of a magnetization and spintronic devices. The field of spintronics has been plagued with the problem of a large energy dissipation as a consequence of the resistive losses that come during the writing of the magnetic state (i.e. reversing the magnetization direction). The primary aim of the work presented here is to investigate and understand a novel heterostructure and materials interface that can be demonstrated as a pathway to low energy spintronics.

In this dissertation, I will address the specific aspects of multiferroicity, magnetoelectricity, and interface coupling that must be addressed in order to reverse a magnetization with an electric field. Furthermore, I will demonstrate the reversal of a magnetization

with an electric field in single and multilayer magnetic devices. The primary advances made as a result of the work described herein are the use of epitaxial constraints to control the nanoscale domain structure of a multiferroic which is then correlated to the domain structure of the exchange coupled ferromagnet. Additionally, the magnetization direction of the ferromagnetic layer is controlled with only an applied electric field at both macroscopic and microscopic scales. Lastly, using this electric field control of ferromagnetism, the first demonstration of a magnetoelectric memory bit is presented.

This thesis details the mechanical design and analysis of the MSL BitBox, which allows the robotic arm of a specially designed Mars rover to replace a drill bit assembly that is attached to the robotic arm with an identical back-up. This is all accomplished though built-in functionality of the robotic arm along with additional mechanisms of the BitBox. The thesis begins by providing an overview of the BitBox and then moves into detailing the design of the components. Then a presentation of the finite element analysis utilized to refine the design is discussed. Finally, the thesis provides an overview of the operation of the BitBox and its interaction with the MSL Rover's robotic arm. The resulting design proved to be very functional, and two BitBoxes were implemented rather than one as originally planned. Variations of the BitBox design could be used for other rover missions that utilize a robotic arm, both on terrestrial planets as well as in deep-sea operations.

Modern adventure games combine storytelling with gameplay using conventions familiar to film and television audiences. These games are different from others in that the experience depends on narrative content, and so is challenging to evaluate for improving content. The subgenre pioneered by Telltale Games uses dramatic choices to shape player experience. I developed and applied an annotation schema to a dataset of 6 player traversals of the first episode of The Wolf Among Us by Telltale Games. The schema supports comparison of player responses consisting of a combination of psychophysiological measurements and self-report events. These events are segmented and classified based on concepts drawn from Robert McKee, including the beat and story values, as well as traditional narrative elements such as character and plot. The results provide evidence that content annotations can facilitate analysis of players responses in longer traversals in spite of different levels of expressivity.

Consonant mutation is a linguistic phenomenon whereby two or more sets of consonant phonemes alternate systematically within roots (or other morphemes) in a way that is not entirely predictable from the phonological environment. A number of Atlantic (Niger-Congo) languages of West Africa exhibit root-initial consonant mutation to mark noun class as well as various verbal morphosyntactic categories. This study treats the historical origin and development of these consonant mutation systems. I argue that despite their typological similarity, the mutation systems of the various Atlantic languages arose for the most part independently, in contrast with the prevailing assumption in the existing literature that these systems were inherited from a common source.

I begin with a typological survey of consonant mutation in the rest of the world’s languages, providing a brief description of each phenomenon, as well as summarizing the theoretical treatments of these phenomena in the literature. I also examine the historical development of these mutation systems where such proposals are extant in the literature. Historically, consonant mutation— which is rather less rare than has often been claimed— generally arises from the interaction between an initial (or less often final) segment of one morpheme with the immediately adjacent segment of a preceding (or following) morpheme. For example, earlier *a-ta and *ak-ta (in which *a- and *ak- are two prefixes which can appear on the root *ta) might develop into a mutation alternation /a-sa/ ~ /a-ta/.

The Atlantic languages which exhibit mutation are Fula and Sereer, Wolof, Kobiana and Kasanga, the Tenda languages, and Biafada and Pajade— all traditionally part of the proposed Northern Atlantic subgroup within Atlantic. The development of consonant mutation in all of these languages is consistent with the type of diachronic origin sketched above. For each of these languages I reconstruct the forms of the original triggers of mutation, as well as the regular sound changes that operated between these triggers and the initial consonants of lexical roots. In doing so I present reconstructions of the phonological and noun class systems of each proto-language, as well as their relevant verbal/pronominal systems. In addition to the regular sound changes that are the ultimate source of mutation, I identify a number of analogical changes that reshaped these systems of alternation in each language.

Finally, I explore the wider question of what genetic relationships exist between the Northern Atlantic languages, using the lexical, phonological, and morphological evidence presented in the preceding chapters. Having established that mutation in the Northern Atlantic languages cannot be attributed to shared inheritance, the principal remaining sources of evidence involve shared lexical material and similarities in the noun class systems. I argue that there are no convincing developments in the noun class systems of the Northern Atlantic languages that can be taken as shared developments of this proposed subgroup, though a strong argument can be made for the grouping of Wolof with Bainunk-Kobiana-Kasanga, and much more tentatively for grouping Biafada-Pajade with this group. Otherwise, the similarities in the noun class systems of Northern Atlantic languages can be attributed to shared inheritance from Niger-Congo. The lexical evidence for this subgroup is somewhat more convincing, but is still extremely limited. Taking into account the patterns of language contact in the area, it seems entirely possible that the few potential lexical innovations of Northern Atlantic can be attributed to borrowing or shared retention. Thus I argue against the genetic unity of the Northern Atlantic subgroup, though all of these languages can be rather securely situated within Niger-Congo at large.

Each cell must achieve the dual tasks of replicating the genetic material and dividing its components into its daughters. This thesis is concerned with how the cell coordinates those fundamental requirements. It approaches this question from the perspective of bacterial physiology, looking at the global relationship between these processes and growth at large. The thesis aims to uncover and test quantitative principles which govern this physiological orchestration. We first review the early quantitative principles, or growth laws, and their modern expansions. This includes cell size control, its connection with the cell cycle, and homeostatic control of each. We then explore these principles in the context of the model organisms E. coli and B. subtilis. Despite their evolutionary distance, we find the two species to be fundamentally similar in their physiological control. Finally, we test the limits of replication and division coordination using single-cell measurements and nutrient-shift experiments. This leads us to reevaluate the canonical Helmstetter-Cooper cell cycle model. Instead of a strict dependency of division on replication initiation, we instead support the view that both processes are controlled by independent threshold mechanisms.

Dramatic choices are the core of the content in contemporary adventure games like those produced by Telltale Games and Dontnod Entertainment, developers of the Life is Strange series. These consist of emotionally-charged and dramatically contextualized player choices rather than strategic or skill-based challenges. Current approaches to understanding and assessing player experience in these games include surveys, interviews, think-aloud and various biometric measurements. These measures, taken alone, are useful for understanding traditional gameplay challenges such as platformers or puzzles but fall short of assessing how emotional content influences player experience or leads to variations in player responses. I collaboratively conducted a study of six players playing the first episode of The Wolf Among Us (TWAU) by Telltale Games, recording gameplay and facial expressions along with heart rate and skin conductivity. To compare and analyze player responses and classify content features, I developed an encoding, the Interactive Cinematic Experience (ICE) schemata, and used it to annotate player traversals with feature locations and player choices. These align player response data to content for comparison and analysis. Researchers can use the model to compare multiple paths through the game that can span hours of gameplay. In order to understand the dataset better, I developed a web-based visual data mining tool, Sherlock, for annotating and analyzing player experience datasets using the schemata and assessed it with a group of game researchers. I compare the encoding method to two other encodings using content from TWAU: Elson's Story Intention Graphs and Mawhorter's choice poetics. Analyzing facial expressions using ICE for the first three chapters revealed a spectrum of variations in responses to content, supporting the presence and effectiveness of emotional content anchors and the characteristics of what I call the Telltale effect. Thematic content that depended on choices differed in the values portrayed from content that was always included. The approach of using multiple player responses, especially facial expression analytics, is essential to a "medium read" of experiences and is a promising direction for interactive narrative research using existing commercial storygame content.