Throughout the history of Marxist theory and practice in Latin America, certain questions recur. What is the relationship between political and social revolution? How can state institutions serve as tools for political change? What is the basis for mass collective political agency? And how can intellectual work contribute to broader emancipatory political movements? Through textual and historical analysis, this dissertation examines how Latin American intellectuals and political actors have reframed and answered these questions in changing historical circumstances. Four episodes in this history are examined: debates between José Carlos Mariátegui and Raúl Haya de la Torre in the late 1920s; the trajectory of the publication Pasado y Presente in Argentina from the 1960s to the 1980s; the uneven path from nationalism to Marxism in the work of Bolivian theorist René Zavaleta Mercado between the 1950s and 1980s; and, most recently, the theoretical efforts of activist-intellectuals in the Comuna group during the last two decades of political change in Bolivia. By examining these episodes in both their theoretical content and historical context, the dissertation argues that the modern concept of constituent power plays a central if sometimes obscure role in theorists’ approaches, while the theory of hegemony, drawn from the work of Antonio Gramsci, informs their strategic perspectives. It also shows, however, how different thinkers have run up against the limitations of these frameworks; mass political events have effects that exceed the dominant conceptual understandings of constituent power and hegemony, and reach beyond the scope of the state, demanding new explanations. The resulting tensions, revealed here by extensively analyzing the case of Comuna in Bolivia during the Pink Tide, have compelled Latin American theorists to recover elided indigenous histories, to forge materialist conceptions of culture and knowledge, to explore aleatory notions of political organization, and to reimagine the political role of intellectuals as that of weaving together, rather than leading, disparate tendencies of political innovation.

These problems are not likely to disappear anytime soon. Theoretical developments on a variety of fronts make it clear that the kinds of archaeological phenomena that must be investigated and interrelated to form reasonably comprehensive interpretations of given points in time are exceedingly diverse and therefore unlikely to yield to any single chronometric technique. Given these circumstances, the prudent archaeologist will seek to use as many techniques as possible, balancing their costs, reliability, and breadth of potential application. It is partly our purpose here to illustrate the use of a technique, lichenometry, that has until now enjoyed use principally in glacial geology but that would seem to deserve consideration in archaeology as well. As with any other chronometric technique, lichenometry has both advantages and disadvantages. We are certainly not holding it up as a panacea; it is hardly that. It is, however, a largely untapped source of information that should prove useful in developing comprehensive archaeological chronologies for some regions.

The atomic force microscope (AFM) is a widespread tool for the study of surfaces, as it allows for the unobtrusive measurement of nanoscale topography. AFM is also versatile, with variants that allow for the measurement of other quantities such as the local surface potential and Young’s modulus. A hurdle to the use of AFM systems is that interpretation of force probe data is nontrivial due to non-idealities of experimental systems including noise and artifacts. This thesis covers two computational techniques to overcome the limitations of AFM systems. First, finite element method simulations are used in conjunction with KPFM studies of vapor-liquid-solid grown silicon nanowires. The nanowires are studied with a variable electric bias applied across them, analogous to a field-effect transistor in operation. Then, batch analysis is applied to extract mechanical information from large amounts of AFM force spectroscopy data from tethered lipid bilayer membrane systems, which are important model systems for studying the mechanics of cell membranes.

MicroRNAs (miRNAs) are a class of endogenous non-coding RNAs that post-transcriptionally co‐regulate networks of genes. The evolutionary history of miRNAs suggests they may play major roles in cell state transitions during the development of complex organisms. Here we characterized the functional role of miRNAs in the generation of induced pluripotent stem cells (iPSCs) from fibroblasts. We found that miRNAs specifically and endogenously expressed in embryonic stem cells (ESCs), including miR-294 and miR-302, greatly enhance the frequency, rate and specificity of fibroblast de-differentiation into iPSCs. Further, the Let-7 miRNAs, a family endogenously expressed in fibroblasts, are potent inhibitors of this same transition. Unexpectedly, a genome-wide screen revealed that the miR-181 family, normally activated in differentiating ESCs, also enhances de-differentiation. To determine the mechanisms by which these miRNA families enhance de-differentiation we developed unbiased high-throughput techniques for identifying and functionally characterizing candidate miRNA targets during this transition. We identified twenty‐six miR‐294 and miR‐181 target genes that act as barriers to de-differentiation, many with cooperative relationships. We further found that both miR‐294 and miR‐181 co-regulate Wnt and TGF‐Beta signaling, with miR-294 additionally regulating Akt signaling. TGF‐Beta inhibition cooperated with Akt or Wnt Activation to enhance iPSC generation. We also identified miR‐294 as a strong inhibitor of the epithelial-to-mesenchymal transition, a known barrier to de-differentiation. These data establish miRNAs as potent regulators of somatic cell reprogramming, demonstrate that single miRNAs act through co‐inhibition of many genes, generate the most comprehensive functionally determined miRNA‐mRNA networks to date, and elucidate interactive relationships among genes that normally suppress de-differentiation.

The theory of biset functors developed by Serge Bouc has been instrumental in the study of the unit group of the Burnside ring of a finite group, in particular for the case of p-groups. The unit group of the ghost ring of the Burnside ring defines a biset functor, and becomes a useful tool in studying the Burnside ring unit group functor itself. We are interested in studying the unit group of another representation ring: the trivial source ring of a finite group. Here we show how the unit group of the trivial source ring and its associated ghost ring define biset functors. Since the trivial source ring is often seen as connecting the Burnside ring to the character ring and Brauer character ring of a finite group, we study all these representation rings at the same time. We point out that restricting all of these representation rings’ unit groups to their torsion subgroups also give biset functors, which can be completely determined in the case of the character ring and Brauer character ring.

In many practical engineering applications, a significant portion of the available information is excluded from the design process due to a lack of obvious mechanisms for its incorporation. In this dissertation, several methods are presented for leveraging such underutilized prior knowledge in application-oriented settings. Three cases, motivated by real-world examples, are considered, addressing controller, estimator, and identification design respectively. In each case, a methodology is presented capturing the key features of the prior knowledge in a characterization which can be readily incorporated into standard solution.

Firstly, a flexible modeling framework is presented for characterizing time-advanced forecast data associated with an exogenous disturbance. The model is incorporated into a disturbance-attenuating feedforward controller which can be synthesized with standard H2 or H∞ methods. The closed-loop performance calculation provides a comparative metric to juxtapose multiple designs and address economic questions, such as sensor placement. A practical example is provided for a wind turbine and lidar sensor with tunable focus range.

Secondly, a modeling framework is presented for characterizing logic-valued measurements that provide timely indication of an associated disturbance event. An estimator is constructed using the fast logic-valued measurement, and known disturbance statistics, to rapidly adjust the disturbance estimate, resulting in improved performance. The framework is applied to a gas turbine (GT) system with transient load disturbance associated with a fast electrical breaker switching measurement. The method is generalized to incorporate multiple disturbance load and breaker pairs.

Finally, a high-fidelity GT (HFGT) model is used to construct a linear GT engine model for control design. The HFGT model generates closed-loop transient simulation data for system identification and the structure of its internal subsystems is leveraged to reduce the complexity of the identification process by excluding unnecessary subsystems. The partition of subsystems is enabled by access to signals in the high-fidelity model which are otherwise unavailable during physical engine testing. The resulting linear engine model can be modularly reconfigured with different fuel subsystem and rotor subsystem models. The linear GT model is validated in closed-loop transient simulations.