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Investigating The Latent Security And Privacy Risks In Consumer-Oriented Software Systems
No full textConsumer-oriented software systems have become the foundation on which consumer data is collected and transported from the consumers to the data processors. They are complex, with various interconnected, heterogeneous components working together, making their security and privacy analysis challenging, and impact on the user uncertain. In this work, we first explore how security threats can arise in novel context in such systems by performing a security evaluation of data-store based smart home platforms and the overall security risks posed by the design of routines within such platforms. We analyze various components of the smart home such as the platform’s permission enforcement mechanism and the apps/services that connect to the smart home that are used during the creation and execution of routines. We find that 1) platform’s permission enforcement and access control model may be broken and allow for attacker’s to bypass user’s consent to perform privileged tasks, 2) around 20% of apps that connect to smart home platforms may have vulnerable SSL connections, and 3) lateral privilege escalation in smart home platforms is possible with the help of routines, wherein we demonstrate by compromising a smart home camera by escalating our privilege gained with a smart home switch app. Secondly, to develop a practical defense against the threats introduced by the routines, we leverage the unique opportunity provided by the smart home i.e., validating incoming state change requests by comparing with the observations gathered by physical devices connected to the platform, for enhancing integrity in smart home platforms. Using this insight, we propose HomeEndorser, which is a practical framework to provide integrity guarantees to smart home platforms. To do so, HomeEndorser endorses (or rejects) requests by apps or services to modify Abstract Home Objects (AHOs) such as home or fire by enforcing integrity policies based on the current state of devices in the home. By protecting against malicious modifications of AHOs, HomeEndorser is able to prevent arbitrary privilege escalation attacks that were possible by exploiting routines. Finally, to understand how effectively stakeholders convey security and privacy risks to the users, we designed the Polityzer framework to systematically analyze the privacy postures of election campaign websites. Using Polityzer, we find a vast majority of election campaign websites lack a privacy disclosure, and even in cases where privacy policies were provided, they were often incomplete. We also found that campaigns may be inadvertently sharing data with other campaigns through common fundraising platforms, without disclosing such sharing.Computer ScienceDoctor of Philosophy (Ph.D.
Mentorship As An Intervention For Chronically Absent Ninth Graders At An Urban High School: An Action Research Study
No full textThis action research study explored the use of mentorship as an intervention to improve the attendance chronically absent ninth grade students at an urban high school. Chronic absenteeism is a phenomenon with multiple compounding negative impacts on students. Moreover, it is a complicated problem with multiple contributing factors and potential root causes. Considering the complexity of the issue, this study used a modified version of Bronfenbrenner’s Bioecological Model of Human Development to identify areas where schools can leverage their influence to solve problems of practice. This action research study employed a mixed methods approach to explore any changes in student engagement, perception of school and attendance importance, attendance behavior, or grades after participating in the intervention. While some research suggests mentorship as a positive intervention for chronically absent students (Allensworth & Easton, 2007; Balfanz & Byrnes, 2013, 2018; Balfanz et al., 2007; DeSocio et al., 2007; Guryan et al., 2017; May et al., 2021), this body of research is not extensive and often does not address the participants involved in this study. Although this study was delimited by both sample size and time, the results show a statistically significant decrease in participant absenteeism. The findings suggest that interventions that target students with a history of chronic absenteeism, and interventions involving mentorship, especially when a school-family relationship is established, hold promise for further decreasing chronic absenteeism. Further study replication for larger samples and longer periods of time in other contexts could help to confirm the presented findings.EducationDoctor of Education (Ed.D.
Contributions Of The Persistent Sodium And M-Type Potassium Currents In The Prebötzinger Complex For Breathing Rhythm Generation
No full textVertebrate animals execute different rhythmic motor behaviors such as walking, swallowing, and breathing, and the generation of that rhythmic activity is governed by central pattern generator network (CPGs), which do not require sensory feedback. The central nervous system is endowed with different CPGs are responsible for determining the appropriate sequence of muscle activation that leads to the correct behavior expression. Breathing is an essential rhythmic behavior and drives the gas exchange between the lungs and the ambient air. Unlike most CPGs that are episodic, and generally quiescent in resting conditions, the respiratory network is active continuously throughout life. The normal breathing cycle is composed by two distinct phases: inspiration and expiration. Inspiration is the inexorable phase and happens due to the active recruitment of the diaphragmatic muscle, while expiration happens passively due to the elastic recoil of the diaphragm and thorax. The CPG for inspiratory activity is the preBötzinger complex (preBötC) in the lower brainstem, and it contains essential excitatory interneurons derived from neuronal progenitor cells that express the Developing brain homeobox 1 (Dbx1) transcription factor. However, the ion channel mechanisms involved in initiating and terminating rhythmic burst activity in vivo remain unsolved. Here, I test the ion channels proposed to orchestrate both mechanisms. The first chapter of my thesis evaluates the “pacemaker theory” which suggests that some preBötC neurons express an intrinsic persistent sodium current (INaP) that gives rise to the voltage-dependent bursting-pacemaker activity, thus driving the inspiratory bursts. I knocked out and knocked down the Scn8a that codes for the sodium channel NaV1.6 which gives rise to INaP. I showed that pacemaker activity is no longer present in rhythmic slices of preBötC from neonatal mice; further, juvenile, and adult mice lacking this subunit still generate breathing activity. The second chapter seeks to understand the role of the M-currents in inspiratory burst termination and opioid-induced respiratory depression. Previous experiments showed that pharmacological blockage of voltage-gated potassium channels from the KV7 family prolongs bursts in a rhythmic slice model of breathing. Surprisingly, I found that genetic knockdown of Kcnq2 and Kcnq3 that comprise M-current does not alter ventilation, metabolis and breathing variability of adult mice. I conclude that Scn8a-mediated NaV1.6 channels underlies INaP-driven pacemaker activity in rhythmic slices, and although it contributes to neuronal excitability in preBötC, this feature is dispensable for rhythm generation. Moreover, Kcnq2/Kcnq3-mediated KV7 M-currents are not necessary for inspiration-expiration phase transition in vivo. These results contribute to understanding the role of specific ion channels in breathing control by using cutting-edge genetic tools, while avoiding unwanted side-effects observed in conventional pharmacological approaches. Moreover, this work shows the importance of whole animals to understand the multifaceted origin of vital motor behaviors like breathing, which was a missing information not achieved with the use of reduced preparations.Applied ScienceDoctor of Philosophy (Ph.D.
Burtons Bay Bathymetric Map
No full textProduced by the United States Geological SurveyVirginia Institute of Marine ScienceEastern Shore Laboratory (ESL
An Action Research Study On The Effects Of Impact Teams As A Form Of Professional Development And Their Influence On Teacher Self-Efficacy
No full textProfessional development (PD) plays a critical role in supporting teacher quality and retention, ultimately affecting student achievement. The pandemic has altered the traditional educational landscape for teachers, making effective PD essential. This qualitative study sought to explore an impact team model (ITM) of PD as an effective form of PD, its influence on teachers’ self-efficacy relating to the four sources of self-efficacy and any instructional changes to their instructional practices after participating in the ITM PD. Findings indicated that honoring teacher time, collaboration, trust, positive feedback, and opportunities for self-reflection, contributed largely to the effectiveness of the ITM PD. The impact team PD provided a safe and trusting space for teachers to take risks and have discussions about instruction. The sessions yielded strong collegial relationships and increased collaboration outside of the PD sessions amongst the participants. In this study, all nine teachers reported shifts in instructional practices. Instructional practices involving classroom management and strategies to engage students have changed after experiencing this PD. Recommendations are offered based on the results of the study.EducationDoctor of Education (Ed.D.
Evaluating Recruitment of American Eel, Anguilla rostrata, in the Potomac River (Spring 2024)
No full textExcerpt from publication: “The Atlantic States Marine Fisheries Commission (ASMFC) adopted the Interstate Fishery Management Plan (FMP) for the American Eel in November 1999. The FMP focuses on increasing coastal states’ efforts to collect American Eel data through both fishery-dependent and fishery-independent studies. Consequently, member jurisdictions agreed to implement an annual survey for young-of-year (YOY) American Eels. The survey is intended to “…characterize trends in annual recruitment of the YOY eels over time [to produce a] qualitative appraisal of the annual recruitment of American Eel to the U.S. Atlantic Coast” (ASMFC 2000). The development of these surveys began in 2000 with full implementation in 2001. Survey results provide necessary data on coastal recruitment success and contribute to the understanding of American Eel population dynamics. The American Eel Benchmark Stock Assessment report (ASMFC 2012) emphasized the importance of the coast-wide survey for providing data useful in calculating an index of recruitment over the historical coastal range and for serving as an early warning of potential range contraction of the species. The most recent American Eel Benchmark Assessment (2023) recommends the continuation of glass eel sampling, but eliminates the requirement to measure length, weight, and pigment stage for glass eels because no discernable trends in these metrics were observed during 20 years of sampling. Funding for the Virginia Institute of Marine Science’s spring survey in the Potomac River was provided by the Potomac River Fisheries Commission, thereby ensuring compliance with the 1999 ASMFC Interstate Fishery Management Plan for American Eels.”Virginia Institute of Marine Scienc
Regulating Under Social Stress: Coping, Cortisol, And Cytokine Reactivity
No full textSocial stressors are common emotion-eliciting interactions that increase feelings of social exclusion, evaluative threat, or rejection (Denson et al., 2009). The Social Signal Transduction Theory of Depression postulates social stressors can upregulate proinflammatory activity, which increases risk for depressive symptoms (Slavich & Irwin, 2014). However, not all individuals who experience social stress will show increased proinflammatory responses. Past literature has found that the use of isolated coping strategies, following social stress, may be associated with proinflammatory activity. Additionally, because lower cortisol responses to social stress result in mild proinflammatory responses, it may be that effective coping is particularly needed to regulate a proinflammatory response under stress when cortisol is blunted. We hypothesized that processing coping strategies, effortful actions to manage the stressor, predict a lower proinflammatory response. In contrast, we hypothesized that expression coping strategies, actions that signal an emotional state, predict greater proinflammatory activity. In addition, we expected stronger relationships between each coping strategy category and proinflammatory reactivity in participants with low cortisol responses to social stress. One hundred and ninety undergraduate participants were randomly assigned to a laboratory-based social stress or control condition. Participants were then asked to report on their use of coping strategies during the control/stress induction. Saliva samples were collected before and after exposure to the control/stress induction. Samples were assayed for cortisol and inflammatory markers (Interleukin (IL)-6, IL-1β, and Tumor Necrosis Factor (TNF)-α). We found that greater processing predicted greater increase in TNF-α and IL-1β under social stress. Additionally greater expression predicted a decrease in TNF-α and IL-6. The interaction between cortisol and coping measures did not predict a change in inflammation. Because our study did not demonstrate expected relationships, we discussed implications for future research, including methods to improve the measurement of coping and inflammatory markers under social stress. One hundred and ninety undergraduate participants were randomly assigned to a laboratory-based social stress or control condition. Salivary cortisol was collected throughout the experimental conditions. Inflammatory markers (Interleukin (IL)-6, IL-1β, and Tumor Necrosis Factor (TNF)-α) were collected before and after exposure to the conditions. Participants were then asked to report on their use of coping strategies. We found that greater processing and lower expression predicted greater change in TNF-α under social stress. However, we did not observe the same relationships for the IL-1β or IL-6. The interaction between cortisol and coping measures did not predict a change in inflammation. Although our study did not demonstrate expected relationships, we discussed methods to improve the measurement of coping and inflammatory markers under social stress.PsychologyMaster of Science (M.Sc.
Low-Rank Matrix And Tensor Models For Data Science Applications
No full textLow-rank approximations play an important role in data science analysis and applications. When the model is linear and the data is represented as a matrix, the optimal rank-r approximation is given by the r dominant factors of the singular value decomposition (SVD). When the model is multilinear and the data is represented as a multi-way array called a tensor, the optimal rank-r approximation may not even exist. Nonetheless, the canonical polyadic decomposition (CP) provides a useful low-rank tensor approximation for interpretability and analysis in a way similar to the matrix SVD but across multiple axes simultaneously. In this dissertation, we focus on two important problems involving low-rank matrix and tensor models for data science applications. The first thrust of this dissertation involves maintaining a summary or sketch matrix from a data stream. We study the trade-offs between an established framework for low-rank approximation of streaming data, called incremental SVD, where a low-rank approximation is maintained for every innovation of data, and randomized sketching, where the data stream is summarized and a low-rank approximation is reconstructed later. We analyze the role of iterative methods with incremental SVD and provide numerical evidence to support our analysis. We evaluate the relative accuracy and computational costs of incremental SVD and randomized sketching on datasets that are challenging for even state-of-the-art batch solvers. We develop a sampling-based convergence criterion to terminate computation early with negligible loss of fidelity. The second thrust involves computing a low-rank CP decomposition model when the input entries are counts, i.e., non-negative integers, that are assumed to follow a Poisson distribution. Our first contribution is a systematic study of state-of-the-art algorithms. Our second contribution is a hybrid method that switches between a deterministic and a randomized algorithm to leverage desirable computational properties from both methods with the overall goal of achieving optimal accuracy-performance trade-off. Our third contribution is a heuristic that detects convergence toward undesirable solutions and implements a restarting technique to improve the likelihood the method will converge to the optimal solution.Computer ScienceDoctor of Philosophy (Ph.D.
The Relationship Among Race, Sense Of Belonging, And The Experiences Of Selected Black Students At A Predominately White Institution
No full textThis qualitative research used Strayhorn’s (2019) theoretical framework to explore the lived experiences of selected Black students at a predominately White institution (PWI). This study sought out to understand the race-related experiences of selected Black students at a PWI, then to understand if those experiences have affected their sense of belonging. Nine undergraduate students were purposively selected to participate in this study. Data collection involved recruitment surveys and two semi-structure interviews. Through an interpretive phenomenological analysis (IPA) lens the following themes emerged from this research study: (a) students’ perceptions of Prestigious University, (b) financial aid, (c) the COVID-19 global pandemic, (d) community, (e) physical spaces on campus, and (f) what it means to “be Black” at a PWI. The results of this research study will be used to elevate the voices and narratives of Black undergraduate college students, shedding light on their lived experiences. This research seeks to provide valuable insight for institutions, practitioners and higher education leaders on addressing issues related to race and sense of belonging, to provide support to students on their college campuses.EducationDoctor of Philosophy (Ph.D.