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<p>Ultra/Luminous infrared galaxies (U/LIRGs) are some of the most amazing systems in the local universe exhibiting extreme star formation triggered by mergers. Since molecular gas is the fuel for star formation, studying the warm, dense gas associated with star formation is important in understanding the processes and timescales controlling star formation in mergers. We have used high resolution (∼2.3”) observations of the local LIRG Arp 299 to map out the physical properties of the molecular gas. The molecular lines 12CO J=3-2, 12CO J=2-1 and 13CO J=2-1 were observed with the Submillimeter Array and the short spacings of the 12CO J=3-2 and J=2-1 observations have been recovered using James Clerk Maxwell Telescope single dish observations. We use the radiative transfer code RADEX to measure the physical properties such as density and temperature of the different regions in this system. The RADEX solutions of the two galaxy nuclei, IC 694 and NGC 3690, show two gas components: a warm moderately dense gas with T_kin ∼ 30-500 K (up to 1000K for NGC3690) and n(H2)~0.3-3×10^3 cm^−3 and a cold dense gas with T_kin~10-30 K and n(H2) > 3 × 10^3 cm^−3. The overlap region is shown to have a well-constrained solution with T_kin ∼ 10-30 K and n(H2)~3-30 × 10^3 cm^−3. We estimate the gas masses and star formation rates of each region in order to derive molecular gas depletion times. The depletion time of each region is found to be about 2 orders of magnitude lower than that of normal spiral galaxies. This can be probably explained by a higher fraction of dense gas in Arp 299 than in normal disk galaxies.</p> / Master of Science (MSc)

<p>The gravitational collapse of a giant molecular cloud produces localized dense regions, called clumps, within which low-mass star formation is believed to occur. Recent studies have shown that limitations of current observing techniques make it difficult to correctly identify and measure properties of these clumps that reflect the true nature of the star-forming regions. In order to make a direct comparison with observations, we produced synthetic column density maps and a spectral-line cube from the simulated collapse of a large 5000 solar mass molecular cloud. The synthetic observations provide us with the means to study the formation of star-forming clumps and cores in our simulation using methods typically used by observers. Since we also have the full 3D simulation, we are able to provide a direct comparison of `observed' and `real' star-forming objects, highlighting any discrepancies in their physical properties, including the fraction of cores which are gravitationally bound. We have accomplished this by studying the global properties of the star-forming objects, in addition to performing a direct correlation of individual objects to determine the error in the observed mass estimates. By correlating the clumps found in the simulation to those found in the synthetic observations, we find that the properties of objects derived from the spectral-line data cube were more representative of the true physical properties of the clumps, due to effects of projection greatly impacting the estimates of clump properties derived from two-dimensional column density maps.</p> / Master of Science (MSc)

This dissertation examines the body of literature that formed around anomalous light apparitions (comets, new stars, the aurora borealis, and rainbows) as it explores questions about the representation and response to celestial and meteorological phenomena during the seventeenth and eighteenth centuries in colonial America. I further consider the ways that these texts’ meanings are informed by rational scientific thought and by other non-scientific or non-rational, emotive, or aesthetic modes of thinking. I consider how these phenomena elicit a set of empirical yet emotionally-charged observational practices that complicate how we understand the roles of the rational and the non-rational in the scientific literature of this period. I argue that non-rational passionate investments are evident within or as part of the period’s rational scientific literature; they act as the impetus for scientific inquiry therefore forming an integral part of the scientific endeavor. This dissertation further explores how the practice of writing about these phenomena generates and facilitates the formation of communities of amateur scientific observers in colonial America. I further investigate how practices of data collection contribute to knowledge about the regular and irregular behaviors of celestial bodies, and how this knowledge impacts everyday practices essential for survival such as farming and travelling. What science writing from this period demonstrates is the ability for multiple ways of thinking to be in play simultaneously; these texts show how several worldviews (i.e. science, Puritanism, popular religion) are intrinsic to each other. Because of their liminality, these texts function outside of traditional categories such science, religion, and natural philosophy. Furthermore, they destabilize traditional conceptions of genre with their blend of rational and non-rational modes of thought and their incorporation of fact and fiction. While I treat these literary texts within their historical contexts, I am also interested in the ways in which these texts reach modern audiences, particularly in academia at a time when the humanities and sciences are positioned against one another. / English

Yes / The field of mental health tends to treat its literary metaphors as literal realities with the concomitant loss of vague “feelings of tendency” in “unusual experiences”. I develop this argument through the prism of William James’ (1890) “The Principles of Psychology”. In the first part of the paper, I reflect upon the relevance of James’ “The Psychologist’s Fallacy” to a literary account of mental health. In the second part of the paper, I develop the argument that “connotations” and “feelings of tendency” are central to resolving some of the more difficult challenges of this fallacy. I proceed to do this in James’ spirit of generating imaginative metaphors to understand experience. Curiously, however, mental health presents a strange paradox in William James’ (1890) Principles of Psychology. He constructs an elaborate conception of the “empirical self” and “stream of thought” but chooses not to use these to understand unusual experiences – largely relying instead on the concept of a “secondary self.” In this article, I attempt to make more use of James’ central division between the “stream of thought” and the “empirical self” to understand unusual experiences. I suggest that they can be usefully understood using the loose metaphor of a “binary star” where the “secondary self” can be seen as an “accretion disk” around one of the stars. Understood as literary rather the literal, this metaphor is quite different to more unitary models of self-breakdown in mental health, particularly in its separation of “self” from “the stream of thought” and I suggest it has the potential to start a re-imagination of the academic discourse around mental health.

Background: Balance is important for performing activities and sports in daily life. Although it is widely accepted, that warming up can increase readiness for exercise, the effect of warming up on balance is unclear as results vary between studies. As warm-up can potentially affect the Star Excursion Balance Test (SEBT) results and physiotherapists use tests to evaluate the effects of interventions, it is important to perform tests in a standardised way. Aim: To investigate the effect of warm-up on dynamic control among injury-free 20–30 year old individuals. Design: Randomised cross-over study. Method: 18 participants performed test A and B, where test A included a warm-up programme and SEBT, and B included only SEBT. The test each participant started with was randomised. Normalised and composite SEBT scores were used to analyse the data. Result: There was no statistically significant difference in SEBT scores for either the dominant or non-dominant leg when compared with and without warm-up. When analysing the difference in mean (SEBT composite %) between with and without warm-up for dominant versus non-dominant legs, a small but significant difference was seen, in the form of a positive effect of warm-up for the non-dominant leg. Conclusion: The results showed that warm-up had no statistically significant effect on either the dominant or non-dominant leg. The difference between the effect of warm-up on the dominant and non-dominant leg was statistically significant as the non-dominant leg was not affected in the same way. Further research is needed to confirm these results. / Bakgrund: Balans är viktigt för att kunna genomföra aktiviteter och idrott i det dagliga livet. Även om det är allmänt accepterat att uppvärmning kan öka beredskap för träningen, är effekten av uppvärmning på balansen oklar då resultaten varierar mellan olika studier. Då uppvärmning kan potentiellt påverka testresultatet vad gäller Star Excursion Balance Test (SEBT) och fysioterapeuter använder tester för att kunna utvärdera effekter av interventioner, är det viktigt att utföra tester på ett standardiserande sätt. Syfte: Att undersöka vilken effekt uppvärmning har på dynamisk kontroll hos skadefria 20–30 år gamla individer. Design: Randomiserad cross-overstudie. Metod: 18 deltagare utförde test A och B, där test A inkluderade ett uppvärmningsprogram och SEBT, och B inkluderade bara SEBT. Testet varje deltagare började med slumpades ut. Normaliserade och sammansatta SEBT-poäng användes för att analysera data.   Resultat: Det förelåg ingen statistiskt signifikant skillnad i SEBT-poäng för vare sig det dominanta eller icke-dominanta benet vid jämförelse med respektive utan uppvärmning. Vid analys av skillnad i medelvärde (SEBT sammansatt %) mellan uppvärmning och inte för dominanta jämfört med icke-dominanta ben sågs en liten, men signifikant skillnad, i form av positiv effekt på uppvärmning för det icke-dominanta benet.  Konklusion: Resultaten visade att uppvärmning inte hade någon statistiskt säkerställd effekt på varken det dominanta och icke-dominanta benet. Skillnaden mellan hur uppvärmningen påverkat det dominanta och icke-dominanta benet var statistiskt signifikant då det ickedominanta benet påverkades inte på samma sätt. Ytterligare forskning behövs för att bekräfta dessa resultat.

Space-time codes (STC) are a class of signaling techniques, offering coding and diversity gains along with improved spectral efficiency. These codes exploit both the spatial and the temporal diversity of the wireless link by combining the design of the error correction code, modulation scheme and array processing. STC are well suited for improving the downlink performance, which is the bottleneck in asymmetric applications such as downstream Internet. Three original contributions to the area of STC are presented in this dissertation. First, the development of analytic tools that determine the fundamental limits on the performance of STC in a variety of channel conditions. For trellis-type STC, transfer function based techniques are applied to derive performance bounds over Rayleigh, Rician and correlated fading environments. For block-type STC, an analytic framework that supports various complex orthogonal designs with arbitrary signal cardinalities and array configurations is developed. In the second part of the dissertation, the Virginia Tech Space-Time Advanced Radio (VT-STAR) is designed, introducing a multi-antenna hardware laboratory test bed, which facilitates characterization of the multiple-input multiple-output (MIMO) channel and validation of various space-time approaches. In the third part of the dissertation, two novel space-time architectures paired with iterative processing principles are proposed. The first extends the suitability of STC to outdoor wireless communications by employing iterative equalization/decoding for time dispersive channels and the second employs iterative interference cancellation/decoding to solve the error propagation problem of Bell-Labs Layered Space-Time Architecture (BLAST). Results show that remarkable energy and spectral efficiencies are achievable by combining concepts drawn from space-time coding, multiuser detection, array processing and iterative decoding. / Ph. D.

Fouling properties of materials such as polyethylene glycol (PEG) have been extensively studied over the past decades. Traditionally, the factors believed to result in protein adsorption resistance have included i) steric exclusion arising from the compression of longer chains and ii) grafting density contribution which may provide shielding from the underlying material. Recent studies have suggested that PEG interaction with water may also play a role in its ability to resist protein adsorption suggesting that steric exclusion may not be the only mechanism occurring during PEG/protein interactions. Star-shaped PEG polymers have been utilized in protein adsorption studies due to their high PEG segment concentration, which allows to increase the PEG chain grafting density compared to that achieved with linear PEG chains. Most studies that have investigated the interactions of tethered linear and star-shaped PEG layers with proteins have considered linear PEG molecules with molecular weights several orders of magnitude smaller than those considered for star-shaped PEG molecules (i.e. 10 000 g/mol vs. 200 000 g/mol, respectively). Additionally, the star-shaped PEG molecules which have been considered in the literature had up to ~70 arms and were therefore modeled by hard-sphere like structures and low chain densities near the surface due to steric hindrance. This resulted in some difficulties to achieve grafted PEG chain overlap for star molecules. Here, triethoxysilane end-functionalized linear PEG molecules have been synthesized and utilized to form star-shaped PEG derivatives based on ethoxy hydrolysis and condensation reactions. This resulted in PEG stars with up to ~4 arms, which were found to result in grafted star-shaped PEG chains with significant chain overlap. Linear PEG derivatives were synthesized so that their molecular weight would match the overall molecular weight of the star-shaped PEG molecules. These 2 PEG molecular architectures were covalently self-assembled to hydroxylated silicon wafers and the thickness, grafting density, and conformation of these films were studied. The adsorption of human albumin (serum protein) on linear and star-shaped PEG films was compared to that obtained on control samples, i.e. uncoated silicon wafers. Both film architectures were found to significantly lower albumin adsorption. / Ph. D.

The synthesis of a variety of novel functionalized polymers using living polymerization techniques to achieve functional and stimuli responsive coatings on silica surfaces are described. Since microscopic features on a surface influence the overall wetting properties of the surface, a systematic investigation of the influence of polymer architecture on the microscopic characteristics of the modified surfaces was studied using silane-functionalized linear and novel star-branched polystyrene (PS). Star-branched modifiers provide functional and relatively well-defined model systems for probing surface properties compared to ill-defined highly branched systems and synthetically challenging dendrimers. Using these simple star-shaped macromolecules it was shown that the topographies of the polymer-modified surfaces were indeed influenced by the polymer architecture. A model explaining the observed surface features was proposed. A living polymerization strategy was also used to synthesize centrally functionalized amphiphilic triblock copolymers. The amphiphilic copolymers exhibited stimuli responsive changes in surface hydrophobicity. In spite of multiple solvent exposures, the copolymer films remained stable on the surface indicating that the observed changes in surface properties were due to selective solvent induced reversible rearrangement of the copolymer blocks. The chemical composition of the copolymers was tailored in order to tune the response time of the surface anchored polymer chains. Thus, the polymer coatings were used to reversibly change the surface polarities in an on-demand fashion and could find possible applications as smart adhesives, sensors and reusable membrane devices. In contrast to the afore-mentioned covalent modification approach, which often leads to permanent modification of surfaces, renewable surfaces exhibiting "universal" adhesion properties were also obtained through non-covalent modification. By employing hydrogen bonding interactions between DNA bases, surfaces functionalized with adenine groups were found to reversibly associate with thymine-functionalized polymers. This study describing the solvato-reversible polymer coating was the first demonstration on silica surfaces. A systematic investigation of the influence of surface concentration of the multiple hydrogen bonding groups and their structure on the extent of polymer recognition by the modified surfaces is also discussed. / Ph. D.

This dissertation examines the key success drivers of hedonic media products like movies and video games, across both the production and distribution phases. Essay I analyzes how public and private funding impact the cultural and economic success of movies, using German film funding as an example. It finds that public funding attracts private investment and increases box office revenues globally, but does not directly improve movie quality ratings. Essay II focuses on the digital home video market and how pricing and timing of releases influence streaming success for purchases and rentals. It reveals differences in consumer behavior, with purchases being more price-elastic and rentals more sensitive to release timing. Essay III investigates how casting popular actors as in-game characters, i.e. star power, drives the success of video games. It finds star power can directly boost game success, especially for genres like horror and RPGs, but counteracts the benefits of multiplayer games. Overall, the dissertation provides valuable insights for entertainment companies, marketers and policymakers on strategically leveraging factors like funding sources, pricing, release timing and star power to enhance the success of hedonic media products across different distribution channels.:Index of Figures VIII Index of Tables IX Abbreviations X 1 Synopsis 1 1.1 Introduction 1 1.2 Summaries of Dissertation Essays 7 1.2.1 Essay I: The Global Impact of Public and Private Funding on Cultural and Economic Movie Success: Evidence from German Film Funding 7 1.2.2 Essay II: Strategic Levers for Sequentially Distributed Digital Products: The Case of Home Video 9 1.2.3 Essay III: From Screen to Screen: How Star Power Drives Video Game Success 12 2 Essay I: The Global Impact of Public and Private Funding on Cultural and Economic Movie Success: Evidence from German Film Funding 14 2.1 Abstract 14 2.2 Introduction 15 2.3 Conceptual and Research Background 18 2.3.1 The German Public Funding System 18 2.3.2 Impact of Quality Signals on Movie Financing (RQ1) 19 2.3.3 The Relationship Between Public and Private Funding (RQ2) 20 2.3.4 Impact of Movie Financing on Cultural Success (RQ3) 21 2.3.5 Impact of Movie Financing on Economic Success (RQ4) 23 2.4 Study Design 25 2.4.1 Data 25 2.4.1 Model 27 2.5 Results 29 2.5.1 Overview 29 2.5.2 Impact of Quality Signals on Movie Financing (RQ1) and Impact of Public on Private Funding (RQ2) 32 2.5.3 Impact of Movie Financing on Cultural Success Variables (RQ3) 32 2.5.4 Impact of Movie Financing on Economic Success (RQ4) 36 2.6 Conclusion 38 2.6.1 Discussion 38 2.6.2 Practical Implications 42 2.6.3 Limitations and Research Outlook 43 Appendix A: Essay I 44 Appendix A.1: Bivariate Correlations 44 Appendix A.2: Model Statistics and Extensive Results 48 Appendix A.3: T-Test Results 62 3 Essay II: Strategic Levers for Sequentially Distributed Digital Products: The Case of Home Video 66 3.1 Abstract 66 3.2 Introduction 67 3.3 Theoretical Framework and Research Background 69 3.3.1 Home Video Success 70 3.3.2 Strategic Distribution Levers and Competition 73 3.3.3 Interactions of Strategic Levers and Preset Factors 75 3.4 Data 75 3.4.1 Basis 75 3.4.2 Pricing and Timing 78 3.4.3 Competition and Preset Factors 78 3.4.4 Controls 79 3.5 Method 80 3.6 Results 83 3.6.1 Impacts of Strategic Levers and Competition 84 3.6.2 Impacts of Preset Factors 87 3.6.3 Moderating Impact of the Strategic Levers 87 3.6.4 Simulation Analysis 92 3.7 Discussion 94 3.7.1 Pricing, Timing, and Competition 94 3.7.2 Preset Factors and Lever Interactions 96 3.7.3 Managerial Implications 97 3.7.4 Limitations and Directions for Further Research 99 Appendix B: Essay II 100 Appendix B.1: Model Robustness 100 Appendix B.2: Comprehensive Results 115 4 Essay III: From Screen to Screen: How Star Power Drives Video Game Success 128 4.1 Abstract 128 4.2 Introduction 129 4.3 Research Background and Theoretical Framework 131 4.3.1 Literature Review 131 4.3.2 Video Games vs. Movies 133 4.3.3 Theoretical Framework 134 4.4 Study Design 139 4.4.1 Data 139 4.4.2 Method 144 4.5 Results 145 4.5.1 Overview 145 4.5.2 Impact of Star Power on Video Game Success 147 4.5.3 Star Power Impact Across Game Traits 149 4.6 Discussion 152 4.6.1 Conclusion 152 4.6.2 Managerial Implications 155 4.6.3 Limitations and Directions for Further Research 156 Appendix C: Essay III 157 Appendix C.1: Bivariate Correlations 157 Appendix C.2: Regression Model T-Test Results 161 Appendix C.3: Extended Results 163 References 167 Curriculum Vitae XII Eidesstattliche Erklärung XIII