VictorJuiz/thesis huggingface dataset:
Politics makes strange bedfellows [electronic resource] : why political and industrial diversity helps contract lobby organizations retain clients and make money
Keywords: Business.

Many studies examine why organizations are shaped by their institutional environment, but few seek to understand the process of organizations attempting to influence the government. This dissertation focuses on an industry dedicated to influencing elite members of the nation-state: contract lobby organizations. These companies serve clients by monitoring government for threats and opportunities, and then promoting or countering changes to the status quo. They do so through coalitions of politically and industrially affiliated lobbyists who engage with policymakers directly. There are two basic approaches to employing lobbyists. One is to specialize by having only one type (for example, only Republicans who specialize in the defense industry). The other is to generalize by having a team balanced across a diverse set of political and industrial categories. I examine these organizational structures to challenge the broadly held position that specialized organizations perform better relative to the generalists they compete with. Contrary to the common finding, this study reveals that a generalist approach is more useful for lobby organizations in terms of reducing failure and increasing revenue growth. This exception occurs because these organizations must engage a group constrained by a norm prescribing collective agreement. Diverse teams are better positioned to monitor the population as a whole by contacting a broad sample, increasing the validity of identified threats and opportunities. They are in a better position to influence the population of Congress members by recruiting observable champions to their cause who belong to several categories, amplifying the legitimacy of their issue and reducing the appearance of controversy. This mechanism establishes a link between the observed organizational structure and organizational performance.
Pore filling and light trapping in solid-state dye-sensitized solar cells [electronic resource]
Keywords: Materials Science and Engineering

Dye-sensitized solar cells (DSCs) are among the promising photovoltaic technologies that could potentially replace the expensive silicon. Liquid electrolyte-based DSCs have the highest efficiency but they suffer from potential stability and encapsulation problems when manufactured at high volumes. Research groups are actively pursuing solid state dye-sensitized solar cells (ss-DSCs), which uses a solid-state hole-transport material to replace the liquid electrolyte. SS-DSCs can potentially achieve higher power conversion efficiencies than the liquid-electrolyte because the open-circuit voltage can be adjusted by the choice of different hole-transport materials. However, current ss-DSCs are limited by both pore filling and electron-hole recombination such that the optimal thickness is around 2 microns, far thinner than the thickness needed to achieve good optical absorption. This thesis presents results that address two challenges facing the field of ss-DSC research - what is limiting the thickness of the device, and what can we do to boost light absorption and power conversion efficiency? In the first part, we describe how pore filling of hole-transport materials inside mesoporous TiO2 films is a limiting factor to the device thickness. This is accomplished by three closely-related pore filling projects: (a) quantifying the pore filling of hole-transport materials inside mesoporous TiO2 films; (b) experimenting with new methods to improve pore filling fraction; and (c) investigating the effect of pore filling on photovoltaic performances of ss-DSCs and the underlying photophysical mechanisms. This brings new physical understanding of the importance of pore filling and how pore filling a effects the photovoltaic performances. In the second part, we describe a new device architecture to increase the absorption through the use of plasmonic back reectors, which consist of two-dimensional (2D) array of silver nanodomes. They are incorporated into the ss-DSCs by nanoimprint lithography, and they enhance absorption through excitation of plasmonic modes and increased light scattering.
Precision cosmology with galaxy cluster surveys [electronic resource]
Keywords: Physics

The acceleration of the universe, which is often attributed to "dark energy, " has posed one of the main challenges to fundamental physics. Galaxy clusters provide one of the most sensitive probes of dark energy because their abundance reflects the growth rate of large-scale structure and the expansion rate of the universe. Several large galaxy cluster surveys will soon provide tremendous statistical power to constrain the properties of dark energy; however, the constraining power of these surveys will be determined by how well systematic errors are controlled. Of these systematic errors, the dominant one comes from inferring cluster masses using observable signals of clusters, the so-called "observable--mass distribution." This thesis focuses on extracting dark energy information from forthcoming large galaxy cluster surveys, including how we maximize the cosmological information, how we control important systematics, and how precisely we need to calibrate theoretical models. We study how multi-wavelength follow-up observations can improve cluster mass calibration in optical surveys. We also investigate the impact of theoretical uncertainties in calibrating the spatial distributions of galaxy clusters on dark energy constraints. In addition, we explore how the formation history of galaxy clusters impacts the self-calibration of cluster mass. In addition, we use N-body simulations to develop a new statistical sample of cluster-size halos in order to further understand the observable--mass distribution. We study the completeness of subhalos in our cluster sample by comparing them with the satellite galaxies in the Sloan Digital Sky Survey. We also study how subhalo selections impact the inferred correlation between formation time and optical mass tracers, including cluster richness and velocity dispersion.
Prediction and novelty in the human medial temporal lobe [electronic resource]
Keywords: Psychology

Prediction is at the core of memory. A memory system stores information about the past in service of preparation for the future, and thus the act of memory retrieval may be viewed as an act of prediction about upcoming events. Converging evidence from animal and compuational models suggests that within the hippocampus, stored memories are compared to current sensory input in order to compute novelty -- when expectation deviates from actual outcome. Specifically, hippocampal subfield CA1 is thought to support this computation of mismatch between past and present. Detection of novelty in turn is hypothesized to modulate encoding processes, providing a mechanism for gating the entry of information into long-term memory. Using high-resolution functional MRI, I examined hippocampal subfield (CA1, CA23/DG[dentate gyrus], subiculum) and medial temporal lobe (MTL: entorhinal, perirhinal, parahippocampal) cortical activation during associative retrieval and associative mismatches in humans. In Experiment 1, subjects performed cued image retrieval and made explicit comparisons of memory to matching or mismatching decision probes. Activity in multiple hippocampal and MTL cortical subregions tracked associative retrieval success, whereas activity in CA1 and perirhinal cortex tracked the presence of associative mismatches. In Experiment 2, subjects viewed sequences of images while performing an incidental task (1-back target detection). In CA1, CA23/DG, and perirhinal cortex, activation was greater when image sequences were presented in rearranged order (mismatch with memory) compared to repeated order (match with memory). In CA1 only, this mismatch enhancement was significantly modulated by prediction strength: the mismatch enhancement was greater when predictions were stronger. In a separate behavioral experiment, recognition memory was found to be better for images that had appeared in rearranged-order (mismatch) than repeated-order (match) sequences, supporting the notion that mismatch detection leads to encoding upregulation. In Experiment 3, subjects viewed sequences of images containing either temporal predicitive information only or combined temporal and spatial predictive information. When novel images were embedded within previously viewed sequences, activation in CA1 was significantly related to subsequent memory for items which had violated predictions (remembered > forgotten), with this enhancement modulated by the amount of predictive information. Together, these data are consistent with the hypothesis that CA1 acts as a comparator, detecting when memory for the past and sensory input in the present diverge. More broadly, the current studies reveal the dynamics of the human hippocampus and MTL cortices during the acts of prediction, novelty detection, and memory encoding -- a continuous cycle of events that enable preparation for the future based on past experience.
Public matters in communication policymaking [electronic resource] : the media ownership debate, 2002-2007
Keywords: Communication

This dissertation critiques the prevailing logics that shape public participation in rulemaking at the Federal Communications Commission (FCC). Influenced by deliberative democratic theory, it argues that an FCC which values public acceptance of its actions shares a responsibility alongside civil society actors and media institutions to welcome, speak with, and answer to publics in communication policy debates. It develops a system of participation that relies on support structures both inside and outside the agency which prioritize inclusive public discussions and which facilitate translation between publics, policymakers, and other stakeholders in rulemaking debate. Using the above framework, which I refer to as a "deliberative model of participation, " this inquiry turns to the case of the media ownership debate. Between the years 2002 and 2007, the FCC conducted two landmark proceedings concerning regulations that limit concentration of ownership in broadcast media. Using interview materials with commissioners and permanent staff as well as FCC, press, and civil society documents, this analysis shows that the complementary efforts of minority leadership at the agency and media reform groups gave new visibility to publics in a rulemaking environment that typically constrains citizen involvement. They engaged in translational activities that educated publics and policymakers, summarized public opposition to media concentration, and amplified public concern to policymakers at the FCC. Though ownership rules were relaxed, the FCC was compelled to explain its decisions and its manner of interactions with publics and to shift its participatory strategies. The analysis suggests that translation is both a process and an outcome and that a fairer, more just framework for participation requires a deeper commitment to citizen-centered debate. The agency needs to commit to new practices that privilege citizens' collective consideration of policy problems and solutions. In line with its discretionary power to enhance notice-and-comment procedures, the agency can—and must—offer a more inclusive environment that supports the communicative actions of publics.
Pulmonary arterial hemodynamics and structure throughout normal development and with arterial stenosis [electronic resource]
Keywords: Bioengineering.

Congenital heart defects (CHDs) are structural abnormalities of the heart and the great vessels that affect approximately 1 of 100 children born. Pulmonary artery stenosis is an obstruction which leads to ventilation-perfusion mismatching, right ventricular hypertension, right heart failure and possibly death. These lesions may be difficult to manage, as physicians cannot know a priori whether a particular stenosis should be treated and what the optimal timing for intervention would be. The general purpose of this work has been to quantitatively characterize the developmental effects of a pulmonary artery stenosis on the hemodynamics and structure of the pulmonary arterial system in small animal models. To enable the study of pulmonary arterial hemodynamics, we introduce the application of phase-contrast magnetic resonance imaging (PCMRI) to the pulmonary arteries of rats and quantitatively describe the pulmonary hemodynamic changes that take place with normal postnatal development. We validate the in vivo flow measurements of PCMRI against echocardiography (ultrasound) and fluorescent microspheres and establish the MR technique as consistent and reliable. We describe pulmonary arterial growth trends to consist of a fast growth spurt until adolescence, followed by a continuous yet slower growth until adulthood and show that relative flow to each lung does not change throughout development. To enable the study of the three-dimensional structure of the pulmonary vasculature, we developed new arterial casting, high-resolution micro-Computed Tomography imaging and image analysis techniques that when applied to the normal development of the lung indicate a continual growth of small arterioles [less than]100[Mu]m in lumen size until adulthood. These two novel techniques when applied to the case of a unilateral pulmonary artery stenosis reveal an abrupt reduction of blood flow to the obstructed lung, and an abrupt increase for the contralateral lung. Changes in arterial distensibility relative to pulmonary flow indicate the loss of an initial compensatory mechanism that attempts to maintain the normal homeostatic state but fails at later stages of development. We find that the hypoperfused lung suffers from hypoplasia, as well as severe vascular growth abnormalities of arterial disorganization, loss of vessels, and enlargement of bronchial arteries that result in increased pulmonary vascular resistance. The contralateral lung also exhibits impaired vascular growth due to increased pulmonary flow and pressure. Despite being larger, this lung also suffers from a loss in vessels that under conditions of stress leads to substantial elevation of pulmonary arterial pressures. These results suggest that early intervention in patients with pulmonary artery stenosis may be of utmost importance in halting and reversing such disadvantageous vascular remodelings.
Punishers become more deviant [electronic resource]
Keywords: Business.

Five studies demonstrate that people who punish are more likely to indicate that they will behave in a deviant manner, relative to non-punishers. Study 1 showed that being the agent of norm enforcement in an economic game resulted in increased deviance intentions. Study 2 provided evidence that the effects on deviant behavior are unique to punishing by ruling out possibilities that merely condemning the transgression, or witnessing another person punish, would lead to deviance. Additionally, an increased sense of power did not mediate the relationship between punishment and deviance. Studies 3 and 4 showed that punishers reported increased moral self-regard, relative to non-punishers and those who condemned. In Study 5, participants who were randomly assigned to sanction a thief by assigning a fair amount of punishment reported increased deviance relative to participants who over-punished or did not punish.
A quantitative analysis of the structure and dynamics of the bacterial chromosome [electronic resource]
Keywords: Physics

Replication and segregation of the chromosome in the bacterium Caulobacter crescentus takes place simultaneously. Although it is known that each arm of the circular chromosome is on average linearly positioned along the cell length, the detailed configuration of the DNA in the cell is not well understood. Furthermore, in replicating bacterial cells, the centromere is segregated by a ParA-dependent mechanism and anchored at the pole, but the segregation mechanism for the rest of the chromosome is not known. To address these questions, I tracked the position and motion of multiple chromosomal loci both in non-replicating and replicating cells. By characterizing compaction of the DNA in non-replicating cells, I show that the DNA in the Caulobacter cells has the mean end-to-end distance that scale as (contour length)0.22, which suggests that compaction of the bacterial DNA is primarily driven by supercoiling. Analysis of the replication/segregation dynamics revealed that Caulobacter chromosome segregation is bimodal: Centromere-proximal DNA is segregated with the centromere at a slow pace whereas the rest of the DNA is segregated much faster. The dynamics of the centromere-distal DNA are consistent with a model where continuous compaction pulls the DNA toward the pole. The results provide a new perspective on the physical configuration of the non-replicating DNA and on the movement and compaction of newly replicated DNA immediately after replication and during its transport from the replisome to the cell poles.
Quantum coherence and interactions in quantum dots [electronic resource]
Keywords: Applied Physics

The behavior of electrons in solid state systems is determined by the interaction of their charge and spin degrees of freedom with each other and with the degrees of freedom of their environment. Whether the interactions manifest themselves by modifying some of the system's properties such as the effective mass in the Fermi liquid picture, or more directly by suppressing transport in the Coulomb blockade model, depends on the details and complexity of the system. This thesis investigates two cases: the Fermi liquid behavior in a system with exchange interactions (the spin 1/2 Kondo model) and effect of Coulomb interactions on the phase coherence of electrons in a quantum dot with single mode leads. The first experiment tests the Fermi liquid theory prediction of a quadratic power law dependence of the electron scattering rate on energy in the non-equilibrium regime. We measure transport though a lateral GaAs/AlGaAs quantum dot that acts as an artificial magnetic impurity coupled to a single reservoir and find that the low energy conductance obeys universal scaling with temperature and bias with a quadratic exponent as expected for the single channel Kondo state. This single particle picture fails when a second independent channel is added and the quantum correlations lead to non-Fermi liquid behavior. To understand how the short range Coulomb repulsion affects phase coherence we measure the quantum correction due to the weak localization of electrons in a quantum dot coupled to a reservoir via perfectly transmitting quantum point contacts. We extract the dephasing time and observe that it continues to increase down to the lowest temperatures, in accordance with the predictions from Fermi liquid theory and in contradiction with previous experiments in zero-dimensional structures. When the phase coherence time of the electrons becomes large enough, we observe the effects of the long range Coulomb repulsion as Coulomb blockade emerges. This was previously assumed to be characteristic of transport through quantum dots with tunneling quantum point contacts (QPCs). We show that despite the fully open QPCs of our device, the coherent backscattering of electrons at zero magnetic field is responsible for Coulomb charging effects and estimate that the residual charge quantization at the lowest temperature is 1/3 electron charge via charge sensing measurements.
Quantum confinement structures for efficient energy conversion [electronic resource]
Keywords: Mechanical Engineering

Quantum confinement (QC) structures present several opportunities for developing next-generation energy conversion devices, due to the ability to tune the electronic and optical properties of a material as a function of size and shape. In the case of solar cells, the ability to tune the bandgap and modify the kinetics of charge relaxation in QC structures suggests the ability to improve broadband solar absorption, and potentially develop devices in excess of the traditional ~32% efficiency limitation of single bandgap devices. However, the ability to fabricate QC solar cells presents several challenges due to the necessity to precisely control feature size and separation, as well as the inherent challenge to extract excited charge carriers from these features before significant recombination losses occur. In this thesis, atomic layer deposition (ALD) was studied as an enabling technology for fabricating 3-D nanostructured QC solar cell architectures. In the first part, the ability to fabricate PbS quantum wells by ALD was developed, and QC effects on the bandgap were demonstrated as a function of film thickness using scanning tunneling spectroscopy (STS). In order to pattern the ALD PbS films in the lateral direction, area-selective ALD of PbS was developed at the micro- and nanoscale using patterned self-assembled monolayers (SAMs). Additionally, a new technique to directly deposit quantum dots (QDs) was developed by utilizing nucleation-limited growth during the initial ALD cycles. The evolution of the size and shape of these dots was studied using plane view transmission electron microscopy (TEM). In the second part, 3-D QC solar cell architectures were developed by ALD. ALD of Al-doped ZnO (AZO) was studied as a transparent electrode material, and the deposition conditions of these films were optimized with respect to conductivity. A standardized MEMS fabrication process was developed to fabricate p-Si/n-ZnO diodes by ALD to aid in charge extraction from QC layers. A fully integrated QD solar cell with PbS QDs integrated into a p-Si/n-ZnO diode with an AZO top electrode was demonstrated. Additionally, the fabrication of 3-D nanostructured templates, including conducting nanowires and etched quartz substrates was studied in order to aid in light scattering and minimize the required thickness of the QD layer, thereby minimizing the diffusion length required for charge extraction. To demonstrate the power of the ALD technique, a single layer of PbS QDs was uniformly deposited on the surface of Si nanowires, and photoluminescence measurements were performed to demonstrate the ability to modify their optical properties through QC effects.
Quantum engineering with quantum optics [electronic resource]
Keywords: Applied Physics

Despite initial set backs in the 1980s, the prospect for large scale integration of optical devices with high spatial-density and low energy consumption for information applications has grown steadily in the past decade. At the same time these advances have been made towards classical information processing with integrated optics, largely in an engineering context, a broad physics community has been pursuing quantum information processing platforms, with a heavy emphasis on optics-based networks. But despite these similarities, the two communities have exchanged models and techniques to a very limited degree. The aim of this thesis is to provide examples of the advantages of an engineering perspective to quantum information systems and quantum models to systems of interest in optical engineering, in both theory and experiment. I present various observations of ultra-low energy optical switching in a cavity quantum electrodynamical (cQED) system containing a single emitter. Although such devices are of interest to the engineering community, the dominant, classical optical models used in the field are incompatible with several photon, ultra-low energy devices like these that evince a discrete Hilbert space and are perturbed by quantum fluctuations. And in complement to this, I also propose a nanophotonic/cQED approach to building a self-correcting quantum memory, simply "powered" by cw laser beams and motivated by the conviction that for quantum engineering to be a viable paradigm, quantum devices will have to control themselves. Intuitive in its operation, this network represents a coherent feedback network in which error correction occurs entirely "on-chip, " without measurement, and is modeled using a flexible formalism that suggests a quantum generalization of electrical circuit theory.