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Mental Health Resources in Texas Public Schools by District Level Socioeconomic Status
No full textThe current landscape of American adolescent mental health is intricate and ever evolving as a
rising number of teenagers are experiencing mental health issues. Disparities in the availability
and quality of mental health treatment exacerbate these conditions, with many affected youths
not receiving or completing necessary care. School is a place in which children spend much of
their time, calling on the need for school provided care, especially in low socioeconomic status
(SES) areas where higher levels of support are needed to fill in the gaps to accessible care. This
study explores the intersection of SES and the availability and quality of mental health resources
in Texas public high schools, aiming to uncover how disparities in SES impact the distribution
and efficacy of these resources. I utilize a mixed-methods approach, combining quantitative data
from surveys conducted with school counselors and administrators, and qualitative insights from
high school and districts level counselors, providing a detailed portrayal of the mental health
service landscape across varying socioeconomic contexts. Quantitatively, this study examines
factors such as counselor-to-student ratios, budget allocations for mental health services, and the
availability of counseling and crisis intervention services across 13 distinct school districts.
Qualitatively, it delves into the experiences and perceptions of 18 high school counselors from
these districts, focusing on their assessment of resource adequacy, training quality, and the
effectiveness of existing mental health protocols. The findings of this study reveal that the
relationship between SES and the availability of mental health resources in schools is deeply
complex. While districts with high levels of poverty sometimes view their resources as adequate,
they contend with issues like excessive workloads for staff. Meanwhile, districts with lower
poverty levels, despite having better organizational structures, encounter challenges comparable
to those in higher poverty areas. There is a pressing need for ongoing, standardized training for
school counselors, universal crisis protocols, and effective referral systems to ensure all students
can access mental health support. Finally, the data suggests that funding models should be
reevaluated, and policies implemented to reduce counselor workloads, possibly through
increased hiring, process optimization, or redistribution of responsibilities
Does Transitional Justice Create a Safer State: An Examination of Post-Transition Experiences in Latin America
No full textLatin America has experienced a great deal of violence throughout the last century. Once stable
democracies became autocracies, and many shifted back to democracy during the third wave of
democratization. (Hagopian & Mainwaring, 2005) As states resumed democracy post-autocracy,
decisions were then made how to deal with past human rights’ violations. As states transitioned
some instituted transitional justice mechanisms including prosecutions, truth commissions,
vetting, and amnesties. In this dissertation I test whether these mechanisms instituted during
transition have a current effect on current citizen buy-in and belief of the new governmental
system. I examine whether the implementation of transitional justice mechanisms creates a safer
state post-transition and use data obtained from America’s Barometer reports to examine the
long-term adherence to and respect for, rule of law. Moreover, I seek to examine whether
different transitional justice mechanisms have differing outcomes with respect to rule of law.
Does the implementation of certain mechanisms – either individually or combined – create a new
state that adheres more closely to law. Not only do I seek to understand the prior state, but also
its transitional justice choices and current perceived citizen security. Through each of these
specific examinations, I seek to answer whether transitional justice achieves its desired goal of
creating a safer state for citizens
Experimental Investigations on Fluid Flow Over Model Wall Mounted Obstacles and Their Implications on the Sediment Transport
No full textThe presence of rigid or flexible obstacles in fluid flow significantly modulates the incoming
flow and exhibits three-dimensional flow features that subsequently interact with sediment bed
in aquatic environments. Owing to the loss of vegetation and its impacts on ecological balance,
the success of vegetation revival and bed stabilization projects relies on the understanding of
physical phenomena that couples modulated fluid flow with sediment transport.
This thesis is primarily divided into two parts – one that focuses exclusively on fluid structure
interactions of finite wall mounted obstacles (WMO), and the other on coupling of modulated
fluid flow due to WMO and sediment transport. Experimental methods such as Particle Image
Velocimetry (PIV), Particle Tracking Velocimetry (PTV), and surface scanning were employed
to analyze flow and sediment dynamics. The first experiments studied wake dynamics and
aerodynamic loads on two side-by-side cylinders with varying gap distances. Results showed
delayed wake recovery and increased turbulence with reduced gap distances. The velocity
fluctuations along the midspan of the cylinder are primarily influenced by mixing of boundary
layer flows at the upper end, while local backflows have a significant impact in the near wake
region. Unlike infinite cylinders, two-dimensional vortex shedding was suppressed due to
three-dimensional effects and background turbulence.
The second series of experiments examined modulated wake flows behind tab-shaped obstacles
to better characterize downstream sediment suspensions. The results showed that while the
sediment volumetric fraction increased with incoming flow velocity, it exhibited non-monotonic
correlations with the tab’s inclination angle. This phenomenon was explained by the combined
influence of wake turbulence kinetic energy and vertical flows. Integrating turbulence mixing
load and vertical velocities with a revised Rouse number better characterized sediment
suspension volume.
The third series focused on bedload transport downstream of flexible plates with varying
aspect ratios and incoming velocities, simulating conditions like aquatic plants. Symmetric
scour holes formed at the sides of the plates, with erosion volume increasing with flow velocity
and decreasing with plate aspect ratio. Near-bed flow statistics indicated that velocity
magnitude primarily regulated erosion volume in flow deflection zones, with lesser plate
deformation resulting in higher velocity magnitudes. A formulation was proposed to estimate
bed erosion intensities as a function of plate aspect ratio and incoming flow speed.
The final experiments explored flow dynamics within flexible canopies under varying flow
velocities and plant heights (aspect ratios). Blade inclination increased with flow velocity,
altering Reynolds stress and streamwise velocity profiles. The drag force within the canopy
decreased at higher velocities due to increased inclination at the canopy apex. Reynolds
stresses distribution within the canopy was mainly influenced by ejections, as shown by
turbulent flow fluctuations, with periodic vortex shedding being predominant. The mean
eddies scaled with the geometry of canopy elements, and the convection velocity within the
canopy was found to be 90% of the bulk velocity.
In conclusion, this dissertation provides a comprehensive analysis of fluid flow and sediment
transport in the presence of wall mounted structures, offering valuable insights for engineering
applications and environmental management
Nonlinear Physics of Wave-Particle Interactions in the Earth’s Inner Magnetosphere
No full textIon temperature anisotropy (T⊥/T∥ > 1) is a key driver of wave-particle interactions and
instabilities in the Earth’s inner magnetosphere. This dissertation addresses the nonlinear
physics associated with two types of electromagnetic waves driven by ion temperature
anisotropy, electromagnetic ion cyclotron (EMIC) waves and magnetosonic (MS) waves.
Spacecraft data from Van Allen Probes, hybrid and test particle simulations, together with a
linear cold plasma dispersion solver, have been utilized.
The role of cold oxygen ions (O+) in the EMIC wave growth is evaluated using linear theory
and nonlinear hybrid simulations. We find that increasing the cold oxygen ion concentration
decreases the EMIC wave growth rate and broadens the spectral width of stop bands near
the helium and oxygen gyrofrequencies. Additionally, an increasing oxygen ion concentration
notably reduces the saturation amplitude of EMIC waves in cases where the helium band
is dominant, while cases with a dominant hydrogen band remain unaffected. Cold ions are
heated during wave excitation, with cold helium ions (He+) heating more significantly than
cold protons (H+) and oxygen ions. However, an increasing cold oxygen ion concentration
reduces the heating efficiency for cold helium ions.
Harmonic EMIC waves, characterized by strong electric or magnetic fields (or both) at
harmonics of the fundamental EMIC mode, are examined through a statistical study based on
Van Allen Probes data for the first time. We categorize EMIC waves into three types based
on their harmonics: (1) fundamental mode only (without higher harmonics), (2) electrostatic
(ES) harmonics, and (3) electromagnetic (EM) harmonics. Our statistical study shows that ES
and EM harmonic EMIC waves predominantly occur on the dayside, outside the plasmasphere
with L > 5 and are associated with a low fpe/fce, a high proton βH , and a strong fundamental
EMIC mode. ES harmonic EMIC waves tend to exhibit a larger Ew/cBw ratio compared to
EM harmonic EMIC waves.
The responses of energetic electrons (∼ 100s keV) to MS waves is analyzed using a test
particle Green’s function model. We investigate the dependence of the bounce resonance
effect on MS wave and background plasma parameters by computing transport coefficients,
including diffusion and advection coefficients. Five wave field parameters, including wave
frequency width, wave center frequency, latitudinal distribution width, wave normal angle
root-mean-square of wave magnetic amplitude, and two background parameters, L-shell value
and plasma density, are considered. The results demonstrate different transport coefficient
peaks resulting from different bounce resonance harmonics. Higher-order harmonic resonances
exist, but the effect of fundamental resonance is much stronger. As the wave center frequency
increases, higher-order harmonics start to dominate. With wave frequency width increasing,
the energy range of effective bounce resonance broadens, but the effect itself weakens. The
bounce resonance effect will increase when we decrease the wave normal angle, or increase
the wave amplitude, latitudinal distribution width, L-shell value, and plasma density.
This dissertation, combining observation and simulation results, provides new insights into
the nonlinear wave-particle interactions driven by ion temperature anisotropy
Organizational Learning and Search in the U.S. Airline Industry: Diffusion of Responsibility, Competitive Advantage of Newness, and Opportunistic Search
No full textThis dissertation studies the entire population of U.S. certificated airlines in the past twenty to
forty years. In the first chapter, I examine whether airlines learn from causal heterogeneity and
explore the moderating effect of performance feedback. In the second chapter, I study the
differences of learning curves among new airlines, old airlines, and old airlines in new shells. In
the third chapter, opportunistic search is proposed as a new mechanism to explain firm behavior,
in addition to problemistic search and slack search
Robust Text-independent Forensic Speaker Recognition Against Multiple Acoustic Domain Mismatch and Spoofing Attacks
No full textVoice-based identification is a critical method in biometric authentication. Forensic voice
authentication is employed by judges, lawyers, detectives, and law enforcement agencies to ei-
ther investigate a suspect or confirm a judgment of guilt or innocence. Using forensic-quality
voice samples for identification poses significant challenges for automatic, semi-automatic,
and manual methods. Speech samples, often recorded in varied naturalistic acoustic settings,
introduce uncertainties and distortions in data quality. In forensic contexts, voices might
be disguised or synthesized to complicate recognition, adding further barriers to accurate
identification. While general Automatic Speaker Verification (ASV) systems handle basic
impersonation efforts well, they remain vulnerable to sophisticated attacks.
Adapting speaker recognition systems to new environments is a common strategy to enhance
models developed from large-scale data for specific, smaller data scenarios. Traditional stud-
ies often focus on adapting to a single domain, neglecting the practical need for models that
accommodate multiple acoustic domains, as commonly required in forensic applications.
Training models across diverse acoustic environments presents unique challenges due to un-
certainties in location and mismatches between reference and field recordings. Employing
small-scale, domain-specific data to train complex neural networks is also problematic due
to these mismatches and potential performance degradation. Fine-tuning, which involves re-
training the model with weights from a well-trained model, is a standard adaptation method.
This work proposes three innovative adaptation techniques based on domain adversarial
training, discrepancy minimization, and moment-matching approaches to enhance perfor-
mance across multiple domains. Our comprehensive experiments show that diverse acoustic
environments significantly impact speaker recognition performance, suggesting potential ad-
vancements in audio forensic research. Domain adversarial training effectively learns features
invariant to domain shifts, discrepancy minimization adapts performance across various do-
mains effectively, and moment-matching, combined with dynamic distribution alignment,
substantially improves performance, especially in noisy environments.
Further advancements in ASV have spurred research into developing robust spoofing detec-
tion systems suitable for real-world applications. ASV systems can be severely compromised
by various spoofing attacks, such as synthetic speech, voice conversion, replays, and imper-
sonation, particularly from novel, synthetic sources. To combat this, we propose a weighted
additive angular margin loss to address data imbalances and improve system generalization
against unseen attacks. Additionally, a meta-learning loss function has been integrated to
optimize the distinction between embeddings of support and query sets, aiding in the creation
of a spoofing-independent embedding space for utterances. We also enhanced data augmen-
tation by crafting adversarial examples with subtle perturbations, and employed an auxiliary
batch normalization to ensure exclusive normalization of these examples. An attention mod-
ule further refines the feature extraction process. Our evaluation on the Logical Access track
of the ASVspoof 2019 corpus confirms the effectiveness of these methods, achieving a pooled
equal error rate (EER) of 0.87% and a minimum t-DCF of 0.0277. These developments offer
potent strategies to mitigate the impact of spoofing attacks on voice recognition systems
In the Shadow of a Saint: Heidegger’s Hidden Confrontation With Augustine Through Kierkegaard and Nietzsche
No full textAugustine, Bishop of Hippo (c. 391-430), is considered in the Christian tradition as one of the
foundational figures within its ecclesiastical history. Augustine’s understanding and exposition
on the Christian faith have left a ripple effect throughout time, even within the realm of Western
philosophers. By investigating Augustine’s Confessions, we may uncover what this ancient
Church Father espoused in regard to the notions of time and care. Saint Augustine writes, “What,
then, is time?...‘Time’ and ‘times’ are forever on our lips. ‘How long did he speak?’ we ask.
‘How long did he take to do that?’ ‘How long it is since I have seen it!’… We use these words
and hear others using them. They understand what we mean and we understand them… Yet their
true meaning is concealed from us.”1 For Augustine, time is woven into the human being’s
thoughts and actions, or “forever on our lips.” Yet, as Augustine states, we often fail in
understanding its true meaning. By uncovering his views on these two concepts, we may see
clearly the remnants he left behind for Søren Kierkegaard and Friedrich Nietzsche. These two
philosophical thinkers would take up the footprint left by Augustine and implement them within
their own writings. This ultimately will culminate into the philosopher who is the main focus of
this work: Martin Heidegger.
In what follows I will lay out a reading of the historical influence of Augustine in Marin
Heidegger’s confrontation with Søren Kierkegaard and Friedrich Nietzsche. It will require us to
consider more closely Augustine’s impact on these important figures and Heidegger’s path
toward Being and Time- namely, Heidegger’s engagement with the thoughts of Søren
Kierkegaard and Friedrich Nietzsche
Prevalence and Activity of CRISPR-Cas in Agriculture: Strategies to Mitigate Antibiotic-resistant Enterococcus Faecalis
No full textThe misuse and overuse of antibiotics has led to the rapid emergence of multidrug-resistant
bacterial strains, which are responsible for more than a million deaths each year. One of the
major causative agents in these infections is Enterococcus faecalis. E. faecalis is a common gut
commensal in humans and many animals, but it is also an opportunistic pathogen that can cause
diseases like endocarditis, urinary tract infections and bacteremia. Previous work has shown that
multidrug-resistant E. faecalis strains often harbor resistance genes on mobile genetic elements
like plasmids, which they acquire and disseminate via horizontal gene transfer. While providing
some advantages, mobile genetic elements in general can also cause metabolic stress to the cell,
and some mobile elements like phages can co-opt bacterial cellular machinery, thus decreasing
their fitness. As a result, bacteria have evolved several defense mechanisms to counteract these
mobile elements. One of the most well-studied defense mechanisms in bacteria is CRISPR-Cas.
It is an adaptive immune system, allowing bacteria to store memories of past infections by
mobile genetic agents, which can then help defend against future attacks. Due to the sequence-
specific nature of CRISPR-Cas, they have been co-opted to act as antimicrobials. Previous work
has shown that CRISPR-based antimicrobials work well in depleting antibiotic-resistant E.
faecalis, in vitro and in the mouse intestine. A crucial environment where antibiotic-resistant
strains emerge is agriculture since it is a major consumer of antibiotics. Given the limited
effectiveness of current antibiotics and the potential promise and documented efficacy of
CRISPR-based antimicrobials, testing the ability of these novel antimicrobials in curbing
resistant bacterial strains in agricultural niches is an exciting prospect. To this end, we first
investigated the prevalence of E. faecalis CRISPR-Cas in agricultural environments and how it
compares to its prevalence in human niches. By analyzing a total of 1,986 E. faecalis genomes
from agricultural and human environments, we found that the prevalence of the functional
CRISPR-Cas subtypes has no significant difference between strains from both environments. We
also tested the targets of these CRISPR systems in both cases and found that a majority of
CRISPR targets – both for plasmids and viruses – were similar across the two. Next, we tested if
CRISPR-Cas could act as an effective barrier against resistance plasmid transfer in an
agricultural niche, modeled using cow manure. Comparing three environments – manure, agar
plate and liquid BHI – we found that CRISPR-Cas was an effective barrier against plasmid
transfer in all three conditions. Finally, we directly tested the ability of CRISPR-Cas
antimicrobials in depleting antibiotic-resistant E. faecalis strains in manure. We found that while
the antimicrobial depleted resistant bacteria in manure, their efficiency was not as significant as
in solid agar. This work lays important groundwork for the study of CRISPR-Cas in the
agricultural context for E. faecalis and other relevant bacterial species, and highlights areas for
improvement in advancing the field of CRISPR-based antimicrobials
Physics of Electrical Discharges in Air
No full textInvestigating electric discharges in gaseous media is of paramount importance due to its wide-
ranging applications in plasma-based technologies and the development of reliable insulation
systems for high-voltage environments. This dissertation presents a comprehensive computational
and experimental study of electric discharges in dielectric air under applied negative DC high
voltage. The computational research includes detailed mathematical modeling, multiphysics
simulations, and extensive numerical analyses, offering a deep dive into the dynamics of air
discharges. This approach is complemented by finite-element simulation methodologies and a
broad parametric analysis, enhancing our understanding of the factors influencing electric
discharge behaviors from a microscopic perspective. Experimentally, the study focuses on partial
discharges in air under conditions that simulate those found in aircraft electrification. This research
provides a thorough characterization of the dynamics of electrical discharges and the behavior of
dielectric air under aviation-related settings, thereby contributing to the design of robust and
compact insulation systems for key electrical components in future electric aircraft
Image, Voice, and Transformation: the “Edenic Icon” in the Works of Fyodor Dostoevsky
No full textThis piece explores the role of the “Edenic icon”—a transformative, textual image of Eden—in
the works of 19th century novelist Fyodor Dostoevsky. A modified formal and structural analysis,
this investigation’s close readings emphasize that such icons, visible throughout several of
Dostoevsky’s major novels, not only challenge and “transform” the way we view each individual
novel, but also unify them, as if by a “gossamer thread,” such that they engender an additional
component of what Mikhail Bakhtin describes as the “generic essence” of Dostoevsky’s work
(Problems 154). Effects on how we understand the “transformative effect” or “function” of the
icon in several of Dostoevsky’s works are discussed—as are the implications of such modes of
interpretation for the study of Dostoevsky, and literature more generally