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This collection contains scholarship produced by the faculty and students at Georgetown University.
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Between Darwin and San Francesco: Zoographic Ambivalances in Mantegazza, Ouida, and Vernon Lee Pireddu, Nicoletta
Viaggi nell'alterità, musei della mente: Paolo Mantegazza tra reperti e ricordi Pireddu, Nicoletta
Anthropology on Screen: Luigi Pirandello, Virginia Woolf Pireddu, Nicoletta
Georgetown Public Policy Review Volume 17 Number 1
Georgetown Public Policy Review Volume 16 Number 1
Georgetown Public Policy Review Volume 15 Number 1
Georgetown Public Policy Review Volume 11 Number 2
Georgetown Public Policy Review Volume 14 Number 1
Library Associates Newsletter: Issue 111 Lauinger Library John Eliot's Bible; From the University Librarian:What's in a Name, Part 2; The Hoya Online; Party at Club Lau; All Our Names; Music as Cultural Mission; La Belle Creole;Infrequently Asked Questions; Healy Building Permit
All the Ships that Never Sailed: A General Model of Transnational Illicit Market Suppression This model predicts progress in transnational illicit market suppression campaigns by comparing the relative efficiency and support of the suppression regime vis-à-vis the targeted illicit market. Focusing on competitive adaptive processes, this `Boxer' model theorizes that these campaigns proceed cyclically, with the illicit market expressing itself through a clandestine business model, and the suppression regime attempting to identify and disrupt this model. Success in disruption causes the illicit network to `reboot' and repeat the cycle. If the suppression network is quick enough to continually impose these `rebooting' costs on the illicit network, and robust enough to endure long enough to reshape the path dependencies that underwrite the illicit market, it will prevail.; Two scripts put this model into practice. The organizational script uses two variables, efficiency and support, to predict organizational evolution in response to competitive pressures. The suppression network should become `flat' and `market-like,' in order to rapidly adapt, and it should maintain a deeply embedded social movement backing the campaign. Success allows for progress through the operational script, which predicts changes in the illicit market using economic theory. Initially, the illicit market uses public `focal points' to conduct business. If the suppressor succeeds in injecting unacceptable risk in these focal points through patrolling, the illicit market is forced to take a firm-like `black market' form. The suppressor shifts to interdiction in response, and if successful again, they subsidize alternate demand path dependencies. Suppression ends either by the suppressor abandoning the attempt or through a path dependency swap to a benign substitute.; I test these theories using historical cases - the British suppression of the Atlantic Slave Trade and the USCG's `Rum War' during Prohibition. Using a multi-method approach inspired by operations research, I use process tracing, statistical analysis, primary historical research, and social network analysis to evaluate changes in relative efficiency and support over time. I then apply the model to contemporary cases - piracy, human trafficking, money laundering, and drug trafficking - for sensitivity and robustness checks. A large-n analysis provides further scoping. Finally, I apply the model to the policy problem of cyberspace-facilitated modern-day slavery. Ph.D.
A-ephrins in Neuropsychiatric Spectrum Disorder Models Neuropsychiatric spectrum disorders such as autism spectrum disorder (ASD) and attention deficit hyperactivity disorder (ADHD) are frequently comorbid and exhibit overlapping abnormalities in both behavioral symptoms and abnormalities in frontal corticostrialal circuits. Thus, it is a particular challenge to identify a "core" molecular pathogenesis that can differentiate between such disorders yet also account for the "spectrum nature" of their phenotypes (clinical presentations) and endophenotypes (underlying neurobiological dysfunction). Given the polygenic and multifactorial etiologies of neuropsychiatric spectrum disorders, there is a need to identify simplifying circuit-level concepts. One strategy proposed for this has been to consider circuit development as a fundamental unit for understanding behavior. This thesis adopted this approach by examining the effects on behavior and anatomy in striatal excitatory microcircuits of gene deletions of A-ephrins, a set of developmental patterning molecules with broad yet complex interactive effects on the development and plasticity of neural macrocircuits and synaptic microcircuits.; First, I tested the hypothesis that specific and combinatorial deletions of ephrin-A ligands are sufficient to generate complex behavioral phenotypes with cross-domain features characteristic of human neuropsychiatric disorders involving dysfunctional frontal-corticostriatal circuitry. Given behavioral evidence in support of this, I next examined dendritic spine morphology in sensorimotor and limbic regions of the striatum seeking evidence that the behavioral phenotype was specifically correlated with changes in frontostriatal circuitry associated with the functional domain of the abnormal behavior. As I did find regional differences in dendritic spine density within the striatum that were correlated with specific learning and memory deficits, I then investigated whether these were accompanied by physiological changes in cell membrane properties or synaptic activity in these striatal regions, and whether the morphological effects detected in adulthood alongside behavioral deficits were present at the much younger developmental age of mice in the electrophysiology experiments. Accordingly, I was able to associate behavioral phenotype with evidence of abnormalities at a circuitry level, but I determined that these effects were not manifest during postnatal development. This raises the possibility that these effects were downstream of general or specific dysfunction along these circuits and may have been experience-dependent. Ph.D.
Degrees of Instructional Explicitness, Depth of Processing, Learning styles and L2 Development: A study on the Spanish Imperfect subjunctive
Degrees of Instructional Explicitness, Depth of Processing, Learning styles and L2 Development: A study on the Spanish Imperfect subjunctive The aim of the present study was three-fold: First, it intended to investigate the effects that different types of instruction varying in explicitness (e.g., Rosa & O'Neill, 1999; Rosa & Leow, 2004), had on 88 intermediate-level Spanish learners' development of the Imperfect subjunctive. Second, it aimed to gain some insight into participants´ minds by employing think-aloud protocols to account for the internal processes that occurred while they carried out a dual task (i.e., reading for meaning and form), and to examine how these processes correlated with post-task performance. Finally, its third goal was to probe deeper into participants' Learning styles (Dornyei, 2005), and, more specifically, into their preference for a deductive or inductive approach to learning grammar rules in the L2. According to their preference, a match or mismatch situation was created with learners matching the treatment received (deductive approach = More explicit condition) or mismatching it (deductive approach = Less explicit conditions) to account for the matched/mismatched design's impact on post-task performance (Valtz, Tare, Jackson, & Doughty, 2013). Participants were semi- randomly assigned to one of six experimental conditions differing in explicitness and in whether they thought aloud or not to control for potential reactivity (Bowles, 2010) (+ Explicit +/- Think aloud (TA), - Explicit +/- TA, Baseline +/- TA). The study consisted of 3 sessions and it followed a pre/post/delayed test design with 2 weeks between each of the sessions. Results showed that the Less explicit condition appeared to perform as well as the More explicit condition immediately after treatment and better 2 weeks after treatment for both interpretation and production tests when compared to the Baseline condition performance. With regards to Depth of Processing, the More explicit condition seemed to elicit more instances of deep processing than the Less explicit or Baseline conditions, and deeper processing significantly correlated with higher comprehension and with a more accurate subsequent production of the target form. With respect to Learning styles, the mismatch condition did positively correlate with better performance at Interpretation immediately after treatment, unlike the matching condition, which failed to yield any positive correlation with post-task performance. Ph.D.
Distress Communication in Cultural Context: Examination of Koreans and Americans Previous research has documented that Asians tend to somatize negative experiences to a greater degree than Westerners. It is posited that somatization may be a more functional communication strategy in Korean than American context. We examined the ways in which Americans and Koreans communicate and respond to distress by analyzing use of and response to somatic words used in narratives. In Study 1, we found that Koreans used more somatic words to communicate distress than Americans. Among Koreans, but not Americans, use of somatic words predicted perceived disclosure quality and expectations of positive reactions (e.g., empathy) from others. In study 2, we found that when presented with distress narratives, Koreans (but not Americans) showed more sympathy in response to narratives using somatic words than narratives using emotional words. These findings suggest that cultural differences in use of somatization may reflect differential effectiveness of somatization in communicating distress across cultural contexts. Ph.D.
Non Equilibrium Electronic Transport in Multilayered Nanostructures Recent advances in strongly correlated materials have produced systems with novel and interesting properties like high Tc superconductors, Mott insulators and others. These novel properties have sparked an interest in industry as well as in academia as new devices are being developed. One such kind of device that can be fabricated is a heterostructure, in which layers of different compounds are stacked in a single direction. Modern deposition techniques like electron beam epitaxy, in which atomic layers of different materials are deposited one at a time creating the device, are capable of fabricating heterostructures with atomic precision. We propose a technique to study heterostructures composed of strongly correlated materials out of equilibrium. By using the Keldysh Green's function formalism in the dynamical mean field theory (DMFT) framework the properties of a multilayered device are analyzed. The system is composed of infinite dimensional 2D lattices, stacked in the z direction. The first and last planes are then connected to a bulk reservoir, and several metallic planes are used to connect the bulk reservoir to the barrier region. The barrier region is the system of interest, also known as the device. The device is composed of a number of planes where the system correlations have been turned on. The correlations are then model by using the Falicov-Kimball Hamiltonian. The device is then connected to the bulk once again from the opposite side using metallic planes creating a symmetric system. In order to study the non equilibrium properties of the device a linear vector potential A(t) = A0 + tE is turned on a long time in the past for a unit of time and then turned off. This in turn will create a current in the bulk, in effect current biasing the device, as opposed to a voltage bias in which opposite sides of the device are held to a different potential. In this document we will explain the importance of the subject, we will derive and develop the algorithm and we will discuss results and challenges obtained from performing the numerical calculations. Ph.D.
Shear-Induced Aggregation Dynamics in a Polymer Microrod Suspension A non-Brownian suspension of micron scale rods is found to exhibit reversible shear-driven formation of disordered aggregates resulting in dramatic viscosity enhancement at low shear rates. Aggregate formation is imaged at low magnification using a combined rheometer and fluorescence microscope system. The size and structure of these aggregates are found to depend on shear rate and concentration, with larger aggregates present at lower shear rates and higher concentrations. Quantitative measurements of the early-stage aggregation process are modeled by a collision driven growth of porous structures which show that the aggregate density increases with a shear rate. A Krieger-Dougherty type constitutive relation and steady-state viscosity measurements are used to estimate the intrinsic viscosity of complex structures developed under shear. Higher magnification images are collected and used to validate the aggregate size versus density relationship, as well as to obtain particle flow fields via PIV. The flow fields provide a tantalizing view of fluctuations involved in the aggregation process. Interaction strength is estimated via contact force measurements and JKR theory and found to be extremely strong in comparison to shear forces present in the system, estimated using hydrodynamic arguments. All of the results are then combined to produce a consistent conceptual model of aggregation in the system that features testable consequences. These results represent a direct, quantitative, experimental study of aggregation and viscosity enhancement in rod suspension, and demonstrate a strategy for inferring inaccessible microscopic geometric properties of a dynamic system through the combination of quantitative imaging and rheology. Ph.D.
Gold Nanoparticle Decorated Carbon Nanotube Field Effect Transistors for Glucose and Gas Sensing The research presented in this thesis focuses on the fabrication, functionalization and characterization of carbon nanotube field effect transistors (CNTFETs) with gold (Au) nanoparticles for gas and glucose sensing applications.; Carbon nanotube field effect transistors are made of an individual carbon nanotube (CNT) in this work. Carbon nanotubes are synthesized using chemical vapor deposition (CVD) on a p-doped silicon/silicon oxide substrate. This process provides mostly single-walled carbon nanotubes (SWCNTs) that are either metallic or semiconducting. Au is deposited onto the carbon nanotube using electron-beam lithography to make source and drain electrodes. Electrical characterization is performed using software controlled pico-amp meter/DC voltage source connecting to a four-probe micromanipulator system.; A simple in-situ electrochemical method to target the deposition of gold, as well as other metallic nanoparticles along a CNTFET is introduced in this research. The transistors are passivated by a thin layer of poly(methyl-methacrylate), or PMMA. Areas of the PMMA along the carbon nanotube are exposed using electron-beam lithography to target the locations where Au nanoparticles need to be placed. An appropriate potential difference is applied between an in-situ sacrificial gold electrode and the CNT, all immersed under a droplet of electrolyte solution. By adjusting the applied voltage and time of deposition, the size of the Au nanoparticle can be controlled from 10 nm to over 100 nm. This method provides better control and is much easier to carry out compared to other site-specific deposition techniques. Such decorated Au nanoparticle/CNTFET heterostructures will allow for a better understanding of CNTFET gas sensing behavior, as well as finding application in site-specific biomolecule anchoring for the development of highly sensitive and selective biosensors, which will be demonstrated in this research work.; This research suggests that when a Au nanoparticle is deposited onto a semiconducting CNT, a local Schottky barrier is created on the CNT side wall. This Schottky barrier changes when exposed to gas molecules, which is the main mechanism for gas sensing of the CNTFET. For glucose detection, Au nanoparticles provide a preferable orientation of the glucose oxidase molecules, which potentially facilitates the electron transfer between glucose oxidase and the CNT. Ph.D.
Mechanism of Gas Sensing in Carbon Nanotube Field Effect Transistors Gas sensors based on carbon nanotubes in the field effect transistor configuration have exhibited impressive sensitivities compared to the existing technologies. However, the lack of an understanding of the gas sensing mechanism in these carbon nanotube field effect transistors (CNTFETs) has impeded setting-up a calibration standard and customization of these nano-sensors for specified gas sensing application. Calibration requires identifying fundamental transistor parameters and establishing how they vary in the presence of a gas and influence the overall sensing behavior. This work focuses on modeling the sensing behavior of a CNTFET in the presence of oxidizing (NO2) and reducing (NH3) gases and determining how each of the transistor parameters, namely: the Schottky barrier height, Schottky barrier width and doping level of the nanotube are affected by the presence of these gases.; Earlier experiments have shown that the carbon nanotube-metal interface is responsible for the observed change in the CNTFET response. The interface consists of the metal contact and the depletion region in the carbon nanotube. A change in the metal work function will change the Schottky barrier height, whereas doping of the depletion region will affect the Schottky barrier width and the doping level of the carbon nanotube. A theoretical model containing these parameters was systematically fitted to the experimental transfer characteristics for different concentrations of NO2 and NH3. A direct correlation between the measured changes in the CNTFET saturated conductance and the Schottky barrier height was found. These changes are directly related to the changes in the metal work function of the electrodes that I determined experimentally, independently, with a Kelvin probe system. The overall change in the CNTFET characteristics were explained and quantified by also including changes due to doping from molecules adsorbed at the carbon nanotube-metal interface through the parameters Schottky barrier width and the doping level. Ph.D.
CIRS Newsletter 17 Center for International and Regional Studies
Water, State Power, and Tribal Politics in the GCC: The Case of Kuwait and Abu Dhabi Lambert, Laurent A. This paper shows that the GCC cities’ remarkable capacity to provide water to all their inhabitants despite the regional aridity should not be explained solely by apolitical factors such as the availability of desalination technologies and massive energy resources. Although acknowledging their importance, this paper demonstrates that the historical evolutions and achievements of the water sectors in Abu Dhabi and Kuwait city over the twentieth century are first and foremost the product of local and regional politics, and of reformist leaders’ agency at various times. Major changes in water governance can also be seen as a tool for, and as a signifier of, broader state reforms and changing politics. After independence, the manufacturing,subsidizing, and massive allocation of desalinated water were part of a political strategy aimed at redistributing oil rent to facilitatethe tribes’ allegiance to the regimes, and to legitimize the increasing power of the new states. By contrast, the region’s recent trend of water privatizations, as in Abu Dhabi, Doha, and Riyadh, for instance,represents a strategy of gradually streamlining the rentier states and liberalizing their economies with a post-rentier perspective.
Unemployment and household formation Ebrahim, Amina; Woolard, Ingrid; Leibbrandt, Murray In comparison to other continents, Africa has received little scholarly attention with regard to household composition. Household composition is endogenous to a variety of welfare issues and little is understood about the determinants of this composition. Understanding the household composition and formation decision may improve our understanding of how the unemployed gain access to resources and how household composition could provide a safety net to the unemployed. However, increasingly, more work is surfacing around the topic in South Africa.