Parikh, Vinay; Gould, Thomas John, 1966-; Briand, Lisa A.; Bangasser, Debra A.; Chein, Jason M.; Ellman, Lauren M. (Temple University. Libraries, 2017)
      Nicotine addiction continues to be a leading cause of preventable death worldwide. Despite the plethora of available treatments for smoking cessation, smoking relapse after attempts to quit remains high. It is possible that impairments in cognitive flexibility and underlying neurochemical circuits in nicotine addicts may foster maladaptive behaviors that affect individuals’ ability to refrain from taking drugs. Here we characterized the effects of spontaneous nicotine withdrawal on cognitive flexibility in mice using an operant strategy set-shifting task. Because frontostriatal circuits are critical for cognitive flexibility and brain-derived neurotrophic factor (BDNF) modulates glutamate plasticity, we also explored the effects of nicotine withdrawal on these neurochemical substrates. Adult male C57BL/6J mice were trained in an operant task that required the animals to switch from using a spatial response-driven strategy to a visual cue-based strategy to achieve rewards. Mice were exp
    • Nietzsche on Suffering, Affirmation, and Modern Tragedy

      Gjesdal, Kristin; Feagin, Susan L., 1948-; Ostaric, Lara; Huddleston, Andrew; Kottman, Paul A., 1970- (Temple University. Libraries, 2019)
      As an artform, tragedy is deeply perplexing. On the one hand, it depicts events that are painful, depressing, and difficult to watch. On the other hand, it is a genre that has been continually replicated, revered, and enjoyed throughout history. I examine Nietzsche’s response to this problem. Nietzsche, I argue, develops a clear response to the paradox of tragedy: Tragedy is valuable because, even though (or precisely because) it is painful to watch, it allows us to affirm life. Interestingly, Nietzsche’s discussion of tragedy is filled with numerous mentions of Shakespeare. I argue that Nietzsche’s comments on Shakespeare emphasize the historically sensitive nature of Nietzsche’s theory of life affirmation. While Nietzsche might seem to be delivering a universal, trans-historical account of life affirmation, his comments on Shakespeare make it clear that life affirmation functions differently in different times and cultures.
    • Nishida's Philosophical Resistance to the Secular-Religion Binary

      Nagatomo, Shigenori; Rey, Terry; Alpert, Rebecca T. (Rebecca Trachtenberg), 1950-; Hammer, Espen (Temple University. Libraries, 2019)
      It has been common in scholarship to frame Nishida Kitarō’s philosophy (西田哲学) as an attempt at overcoming the dualities of Western modernity. But what has been downplayed in this reading is how Nishida re-interprets the concept of religion in a way that challenges modernist theories of religion, with implications that speak to the problematics of the secular-religion binary today. Nishida’s view of religion, as an existential form of awareness, and a structuring logic of historical reality, with its own epistemological criteria, contrast with the theoretical accounts that assume religion is opposite to the real—or that religion is subordinate to the secular. By designating religion as a logical category that coincides with the real, Nishida’s philosophical standpoint offers a means to not only re-think the relationship between the secular and the religious, but to re-think the relationship between the West and the rest of the world, because if rationality is not a superior category over religion, then the races, cultures, and ethnicities that have been historically subordinated are placed on an equal epistemological footing with Western philosophy and science. In this sense, Nishida’s philosophy of religion allows us to think critically about the “problem of religion” and presents a discussion that can also be used to address some of the issues raised within post-colonial studies.

      Wengryniuk, Sarah E.; Dobereiner, Graham; Andrade, Rodrigo B.; Frontier, Alison J. (Temple University. Libraries, 2019)
      Hypervalent iodine (HVI) reagents are easily accessed, highly tunable, mild, selective oxidants that are less toxic and more environmentally benign compared to their heavy metal counterparts. λ3-Iodanes, which possess an iodine center bound to one aryl substituent and two heteroatom ligands, have been the subject of recent interest due to their electrophilicity and hypernucleofugality. A central focus of the Wengryniuk laboratory has been the further development and application of a class of electrostatically activated (bis)cationic nitrogen-ligated HVI (N-HVI) reagents. N-HVIs feature datively bound heterocyclic ligands which results in dramatically enhanced electrophilicity and redox potentials. Despite being a highly tunable platform for reagent development, N-HVIs remain a relatively underexplored class of λ3-iodanes. This dissertation focuses on demonstrating N-HVI’s synthetic potential and developing novel variants to enhance their synthetic utility. Chapter 1 of this dissertation serves as a general background and introduction to nitrogen-ligated HVI reagents. Chapter 2 outlines our efforts in N-HVI library expansion, novel syntheses, and characterization. With a library of 33 novel N-HVIs in hand, ligand effects on N-HVI reactivity were analyzed via qualitative and quantitative methods. Chapter 3 describes our first synthetic application of N-HVIs in the development of novel oxidative rearrangements of simple and complex cyclic alcohols. This chapter describes the chemoselective ring expansion of 2° and 3° cyclic alcohols accessing medium-sized cyclic acetal products in good to excellent yields with applicability to Complexity-to-Diversity (CTD) efforts. Chapter 4 demonstrates our initial efforts toward the development of another synthetic method where the functionalized N-heterocyclic ligands of the N-HVIs can be regioselectivity incorporated into a molecule following N-HVI activation of an olefin. The pyridinium lactone salts formed from olefinic acids were isolated in excellent yields via simple trituration, supplying a synthetically useful functional handle that was easily derivatized via known methods. These four chapters summarize the current state of the research with nitrogen-ligated HVI salts, expand upon our initial publications to highlight the development of novel heterocyclic syntheses, and provide a useful guide to further explore the reactivity of these tunable reagents.
    • No Child is an Island: A Study of the Effect on Student Sense of Belonging Through Their Participation in a Formal Program of Character Education

      Shapiro, Joan Poliner; DuCette, Joseph P.; Gross, Steven Jay; Sanford-DeShields, Jayminn (Temple University. Libraries, 2016)
      As more schools consider ways to help students to develop not only academically but also socially and emotionally, school personnel look to formal programs of character education to help address the needs of the whole child. Of these programs of character education, Berkowitz and Bier (2005) posit that effective programs begin by promoting positive social relationships within the school. One measure of the quality of the social relationships in schools is reflected in the level of belonging or connectedness that students feel toward their school and members of the school community. Consequently, the purpose of the present study was to further the investigation of the construct of sense of school belonging and its relationship to formal programs of character education. Eighth-grade students (732) from five middle schools – three character program schools and two non-character program schools – were surveyed measuring sense of school belonging by their responses on the total score of the Psychological Sense of School Membership (PSSM) scale developed by Goodenow (1993) and on the four sub-scores of the PSSM demonstrated by Ye and Wallace (2013). No significant differences were found for student sense of belonging between character program schools and non-character program schools. However, the study also investigated the effect of structural and perceptual elements of character education programs that were found to positively relate to student sense of school belonging. Students who identified themselves as being part of a character education group in their school reported significantly higher levels of sense of belonging (on the total score of the PSSM and on the PSSM factors of Identification and Participation in School, Perception of Fitting in Among Peers, and Generalized Connection to Teachers) than those students who did not identify as being part of a character education group. In addition, students reported statistically significant higher levels of sense of belonging a) the more they felt accepted by other students in their group, b) the more they felt accepted by their adult group advisor, c) the more they felt able to express opinions in their group, d) the more they felt their group was like a family, and e) the more they felt character education groups made their school a better place. Sense of belonging was also positively related to more frequent opportunities for character education group meetings and to a common school language that emphasized moral character more than performance character.
    • No Child Left Behind: The Answer to Preparing Students for Careers, or the Demise of Career and Technical Education?

      Gross, Steven Jay; Shapiro, Joan Poliner; Partlow, Michelle Chaplin, 1941-; DuCette, Joseph P.; Farley, Frank (Temple University. Libraries, 2014)
      This qualitative case study is designed to document the impact of No Child Left Behind (NCLB) on career and technical education (CTE) in Pennsylvania. The research was conducted utilizing a qualitative case study protocol on two specific CTE Centers in the suburban Philadelphia area. The study centered on the following question. Has compliance to the accountability components of NCLB impacted the delivery of secondary education in CTE centers in the Pennsylvania? The study identified the changes that have occurred to selected CTE centers in the NCLB era. The assessment mandates of federal policy NCLB are narrowly focused in academic curriculum. The data used to answer the questions was accumulated through interviews with facility staff and the examination of archival records at the two specific centers to be researched. This study determined the impacts of NCLB on the facilities. The impacts included; decreased enrollment, increased academic and testing focus, reduction in technical budgets, increase in academic budgets, increase of special education students, staff changes for the increase of academic areas, morale issues, program changes, shifts in staff development, facility changes, negative publicity and public image due to academic reporting in the media. Questions for future study. What are the costs, financial and opportunity related to the reduction in CTE for increased academics? How many students have been denied the opportunity of attending or completing CTE programs? Why there isn't an alignment of NCLB and IDEA goals? What is the emotional impact to our students who keep getting told they are below basic? The conclusion from this study suggests that the public education system in this country needs to be more centered on actual student outcomes and preparing students with marketable skills and not based on the narrow focus of academic test scores.

      Hunt, James M. (James Michael); Morrin, Maureen; Venkatraman, Vinod; Chakravarti, Dipankar (Temple University. Libraries, 2014)
      Envy, as a result of upward social comparisons, is an unpleasant emotion that occurs when a consumer sees others as being more advantaged than him- or herself, in terms of achievements and/or possessions. Envy may drive the envious consumer to 'compete' with the envied-target through purchase of similar or better products; for that reason, envy is frequently used in advertising to motivate consumers to buy better products. While envy may be good for businesses as it may promote economic growth through the “keeping up with the Joneses” mechanism, envy tends to bring destructive behavior to consumers, especially in the long run. Departing from the view to maintain consumer welfare, we argue that envy should be reduced or perhaps, temporarily deactivated. Through a series of studies, we attempt to see if envy, as an emotion, can be transformed into an object upon which physical actions can be performed to destroy it, which thus reduces or temporarily deactivates envy. Furthermore, we want to see if any of these actions, assuming that envy is reduced or temporarily deactivated as a result, would lead consumers to adopt more pro-social behavior, as opposed to typical destructive behavior of envy.
    • No Principal Left Behind: Leadership and Ethical Dilemmas in the Turbulent Era of School Accountability

      Gross, Steven Jay; Horvat, Erin McNamara, 1964-; Partlow, Michelle Chaplin, 1941-; DuCette, Joseph P.; Shapiro, Joan Poliner (Temple University. Libraries, 2009)
      In 2003, Mid-County North High School (pseudonym), a large suburban, rather affluent school did not make Adequate Yearly Progress (AYP) under the No Child Left Behind Act. The school's special education population was unable to meet the proficiency requirements of the Mid-County's state, and as such received a "failing" label from the state. The irony in this is that North High School (NHS) and the Mid-County District have a documented legacy of excellence -even on the very assessments upon which the "failing" assessments were based. This single-site, qualitative case study, was designed to investigate the real-life dilemmas, ethical, professional, and personal, that the school leaders at NHS and in the Mid-County School District encountered after the school did not make AYP. The perceived internal pressures caused by the possible competition of a school leader's personal and professional values, as well as the necessity for leaders to guide their school toward making AYP, were investigated. In addition to internal pressures, the study attempted to uncover the perceived pressures faced by the leaders within the organizational structure of the school and school district, from the community, media and government. In addition, the study was designed to unveil school leaders' reactions to these perceived pressures. This study used semi-structured interviews with 12 school leaders, including central office and building level leaders, as well as teachers, a parent, and a school board member. In addition to interviews, pertinent documents, and artifacts were analyzed. The interview and document data were then coded using a qualitative analysis program, TAMSAnalyzer. The constant comparative method (Glaser and Strauss, 1967) was used to analyze the data in terms of the study's two theoretical frameworks: Turbulence Theory (Gross, 1998) and Multiple Ethical Paradigms (Shapiro and Stefkovich, 2001). The data revealed three dominant themes: (a) Turbulence Happens: School Leaders Are Forced to Respond to Externally Imposed Accountability in the Era of NCLB and AYP; (b) Flight School: School Leaders' Ethical Codes and Experience Prepare them to Navigate Through Turbulence; (c) Pilot to Co-Pilot: School Leaders Communicate, Collaborate, and Innovate to manage the Turbulence of Not Making AYP.
    • No Uncertain Trumpet: Carl McIntire and the Politicization of Fundamentalism

      Watt, David Harrington; Wells, Jonathan Daniel, 1969- (Temple University. Libraries, 2010)
      Cold War era preacher Carl McIntire played a significant role in the politicization of fundamentalism during the 1930s, '40s, and '50s. His libertarian political philosophy was shaped by the denominational politics in the Presbyterian Church of America during the fundamentalist - modernist controversy.

      Letzter, E. S. (Edward S.), 1958-; Datskovsky, Boris Abramovich; Lorenz, Martin, 1951-; Beigel, Richard (Temple University. Libraries, 2008)
      This dissertation is concerned with noncommutative analogues of formal power series rings in multiple variables. Our motivating examples arises from quantized coordinate rings; the completions of these quantized coordinate rings are iterated noetherian skew power series rings. Our first focus is on $q$-commutative power series rings, having the following form: $R = k_q[[x_1,\ldots,x_n]]$, where $q = (q_{ij})_{n\times n}$ with $q_{ii}=1$ and $q_{ij} = q^{-1}_{ji} \in \k^{\times}$ and where $x_jx_i = q_{ji} x_i x_j$. The corresponding skew Laurent series ring is $L=k_q[[x_1^{\pm 1},\ldots,x_n^{\pm 1}]]$. We first study the ideal structure of $L$. We prove that extension and contraction of ideals produces a bijection between the set of ideals of $L$ and the set of ideals of the center $Z$ of $L$. This bijection further produces a homeomorphism between $\spec L$ and $\spec Z$. Applying the analysis of $L$ to $R$, we prove that the prime spectrum $\spec R$ can be partitioned into finitely many strata each homeomorphic to the prime spectrum of a commutative noetherian ring. The rings $R$ and $L$ are completions, respectively, of the quantum coordinate ring of $n$-space and of the $n$-torus. Our second focus is on power series completions of iterated skew polynomial rings with nonzero derivations. Given an iterated skew polynomial ring $C[y_1;\t_1,\d_1]\ldots [y_n;\t_n,\d_n]$ over a complete local ring $C$ with maximal ideal $\m$, we prove, under suitable assumptions, that the completion at the ideal $\m + \left\langle y_1,y_2,\ldots,y_n\right\rangle$ is an iterated skew power series ring. Under further conditions, this completion is a local, noetherian, Auslander regular domain. Applicable examples include the following quantized coordinate rings: quantum matrices, quantum symplectic spaces, and quantum Euclidean spaces. Results in this dissertation are included in the following two preprints: 1. Prime ideals of $q$-commutative power series rings (joint with E. S. Letzter), submitted for publication. 2. Completions of quantum coordinate rings, to appear in Proceedings of the American Mathematical Society.

      Metz, Andreas; Santamore, Deborah; Burkhardt, T. W. (Theodore W.), 1940-; Yuen, Tan (Temple University. Libraries, 2017)
      With the advance in nanotechnology, we are more interested in the "smaller worlds". One of the practical applications of this is to measure a very small displacement or the mass of a nano-mechanical object. To measure such properties, one needs a very sensitive detector. A quantum point contact (QPC) is one of the most sensitive detectors. In a QPC, electrons tunnel one by one through a tunnel junction (a "hole"). The tunnel junction in a QPC consists of a narrow constriction (nm-wide) between two conductors. To measure the properties of a nano-mechanical object (which acts as a harmonic oscillator), we couple it to a QPC. This coupling effects the electrons tunneling through the QPC junction. By measuring the transport properties of the tunneling electrons, we can infer the properties of the oscillator (i.e. the nano-mechanical object). However, this coupling introduces noise, which reduces the measurement precision. Thus, it is very important to understand this source of noise and to study how it effects the measurement process. We theoretically study the transport properties of electrons through a QPC junction, weakly coupled to a vibration mode of a nano-mechanical oscillator via both the position and the momentum of the oscillator. %We study both the position and momentum based coupling. The transport properties that we study consist of the average flow of current through the junction, given by the one-time correlation of the electron tunneling event, and the current noise given by the two-time correlation of the average current, i.e, the variance. The first comprehensive experimental study of the noise spectrum of a detector coupled to a QPC was performed by the group of Stettenheim et al. Their observed spectral features had two pronounced peaks which depict the noise produced due to the coupling of the QPC with the oscillator and in turn provide evidence of the induced feedback loop (back-action). Benatov and Blencowe theoretically studied these spectral features using the Born approximation and the Markovian approximation. In this case the Born approximation refers to second order perturbation of the interaction Hamiltonian. In this approximation, the electrons tunnel independently, i.e., one by one only, and co-tunneling is disregarded. The Markovian approximation does not take into account the past behavior of the system under time evolution. These two approximations also enable one to study the system analytically, and the noise is calculated using the MacDonald formula. Our main aim for this thesis is to find a suitable theoretical model that would replicate the experimental plots from the work of Stettenheim et al. Our work does not use the Markovian approximation. However, we do use the Born approximation. This is justified as long as the coupling between the oscillator and QPC is weak. We first obtain the non-Markovian unconditional master equation for the reduced density matrix of the system. Non-Markovian dynamics enables us to study, in principle, the full memory effects of the system. From the master equation, we then derive analytical results for the current and the current noise. Due to the non-Markovian nature of our system, the electron tunneling parameters are time-dependent. Therefore, we cannot study the system analytically. We thus numerically solve the current noise expression to obtain the noise spectrum. We then compare our noise spectrum with the experimental noise spectrum. We show that our spectral noise results agree better with the experimental evidence compared to the results obtained using the Markovian approximation. We thus conclude that one needs non-Markovian dynamics to understand the experimental noise spectrum of a QPC coupled to a nano-mechanical oscillator.

      Caldwell, Corrinne A.; DuCette, Joseph P.; Kreinberg, Steven; Cornelius, Jeffrey M.; Davis, James Earl, 1960- (Temple University. Libraries, 2009)
      The purpose of Non-credit community arts programs: A comparative case study of three programs within research universities is to examine the perceptions of the various stakeholders of non-credit community arts programs to determine the perceived benefits received by all stakeholders from the non-credit program, the university, and its surrounding community, the variables of a successful program, and the sustainability of these programs within their parent institution. The research methods used included a preliminary 41-question survey distributed to 76 non-credit community arts programs embedded within colleges or universities to determine the specific programs within research universities. These 76 collegiate divisional community schools of the arts belong to the 400 members of community arts schools in the National Guild of Community Schools of the Arts. The results of the survey were used to determine the three non-credit community arts programs that were selected for the case study. The case study of each of the three non-credit community arts programs was used to learn the perceptions of the various stakeholders of each of the programs and their respective parent institution. The stakeholders included research university administrators, the non-credit program's executive administrators, the program's faculty, staff, students, and parents of students that participate in the non-credit community arts programs. Site visits, interviews, either in person or via phone conversation, and review of printed materials were employed to obtain from the various stakeholders the perceived benefits of these non-credit community arts programs, the variables that contribute to a successful program and their sustainability within the research university. The diversity of the stakeholders interviewed provided a thorough observation of these programs from varying perspectives to discover their impact on the individual students as well as the university, its internal community and the community-at-large.
    • Non-Equilibrium Dynamics of Second Order Traffic Models

      Seibold, Benjamin; Queisser, Gillian; Klapper, Isaac; Rosales, Rodolfo R. (Temple University. Libraries, 2020)
      Even though first order LWR models have many limitations, they are still widely used in many engineering applications. Second-order models, on the other hand, address many of those limitations. Among second-order models, the inhomogeneous Aw-Rascle-Zhang (ARZ) model is well-received as its structure generates characteristic waves that make physical sense. The ARZ model --- and other $2\times 2$ hyperbolic systems with a relaxation term --- possess a critical phase transition: whenever the sub-characteristic condition (SCC) is violated, uniform traffic flow is unstable, and small perturbations grow into nonlinear traveling waves, called jamitons. The case where the SCC is satisfied has been studied extensively. However, what is essentially unstudied is the question: which jamiton solutions are dynamically stable? To understand which stop-and-go traffic waves can arise through the dynamics of the model, this question is critical. This dissertation first outlines the mathematical foundations of the ARZ model and its solutions, then presents a computational study demonstrating which types of jamitons are dynamically stable, and which are not. After that, a procedure is presented that characterizes the stability of jamitons. The study reveals that a critical component of this analysis is the proper treatment of the perturbations to the shocks, and of the neighborhood of the sonic points. The insight gained from answering the question regarding the dynamical stability of jamitons has many applications. One particular application presented here is deriving an averaged model for the ARZ model. Such a model is as simple to solve (analytically and numerically) as the LWR model, but nevertheless captures the cumulative effects of jamitons regarding fuel consumption, total flow, and braking events.
    • Non-Parasitic Warlords and Geographical Distance

      Diamantaras, Dimitrios; Ritter, Moritz B.; Zusai, Dai; Rosenthal, Edward C., 1959- (Temple University. Libraries, 2013)
      This dissertation presents an extension of the warlord competition models found in Skaperdas (2002) and Konrad and Skaperdas (2012). I consider two non-parasitic warlords located on a line. Each warlord allocates resources for the extraction of natural resources, the production of goods and services, and conflict with the opposing warlord. Within the symmetric rates of seizure model, I use three different forms of the contest success function, a primary tool in the conflict theory literature, in my analysis. I show that the warlord closer to the point of conflict will invest less into the hiring of warriors and more into the production of goods and services, yet wins a larger proportion of total goods and services produced within the economy. Under certain conditions, the placement of the point of conflict at the midpoint between the two warlords maximizes the total resources toward war and minimizes total production. Under the asymmetric rates of seizure model, I find that the warlord closer to the point of conflict invests more in warfare and less in production; that is, results that counter what is found in the symmetric model.

      Schmitz, Mark F.; Tellez Merchán, Marisol; Bhoopathi, Vinodh (Temple University. Libraries, 2017)
      Background: Early Childhood Caries (ECC) is one of the most common chronic illnesses among young children, affecting around 23% of children 2-5 years old, leading to pain, discomfort, and poor quality of life. It is a multi-factorial disease that develops through the combined effects of bacteria, tooth morphology, fermentable carbohydrates, time, and various social factors. Several studies have investigated the associations between dental caries and non-traditional factors acquired during the first years of life including; mode of delivery, breastfeeding, and Environmental Tobacco Smoke (ETS). However, the literature on these associations has been inconsistent. Objective: To investigate the unadjusted and adjusted associations between the presence of Early Childhood Caries (ECC) and Severe-ECC (S-ECC), and three non-traditional factors: breastfeeding, mode of delivery, and ETS, among children 1-5 years old. Methods: A cross-sectional design was employed, and a sample of 112 caregiver/ child dyads was recruited from the ongoing flow of patients at Temple University Maurice H. Kornberg School of Dentistry (TUKSoD). After consent, subjects completed a questionnaire and received a standard intra-oral examination and the American Academy of Pediatric Dentistry (AAPD) Caries-risk Assessment Tool (CAT) by a student doctor. The study was approved by the Temple University Institutional Review Board (Protocol # 23885). Chi-square tests, two-sample t-tests and bivariate logistic regressions were used to assess the unadjusted associations. Two multivariable logistic models were developed for ECC and S-ECC and included demographics, overall CRA, and the three non-traditional risk factors. Results: The prevalence of ECC and S-ECC were 61% and 30%, respectively. The following variables were significant in the unadjusted analysis for both ECC and S-ECC: child’s age, maternal educational attainment, overall AAPD CAT classification, sugary snacks per day, presence of plaque on child’s teeth and ETS. Exposure to ETS was associated with an increased adjusted odds ratio for ECC (aOR=5.39 [95% CI: 1.14-25.33], P=0.033), but not for S-ECC. Furthermore, C-section birth was associated with a decreased adjusted odds ratio for both ECC and S-ECC, respectively (ECC: aOR=0.132 [95% CI: 0.02-0.72], P=0.02; S-ECC: aOR=0.141 [95% CI: 0.026-0.748], P=0.021). With inclusion of the AAPD CAT, demographics, and the three non-traditional factors, the overall model accuracy at predicting ECC was 82.2%. Conclusions and Clinical Relevance: In this study of urban, predominantly African American, and low income children, ECC was found associated with two non-traditional factors, ETS and mode of delivery, suggesting that including them in CRA may improve prediction of future dental caries, and aid in the prevention and treatment of disease. Results from this study support the notion that ECC is a multi-factorial disease, and highlights the importance of adopting oral health education among caregivers.

      Yang, Xiao-feng; Wong, Hong; Khan, Mohsin; Hu, Wenhui; Zhang, Yanqiao (Temple University. Libraries, 2022)
      Nonalcoholic fatty liver disease (NAFLD) is currently the most common cause of abnormal liver function in countries with western-style high fat, high cholesterol diets. Liver damage associated with NAFLD may lead to liver cirrhosis, end-stage liver disease and hepatocellular carcinoma (HCC). Additionally, recent data suggest that nonalcoholic steatohepatitis (NASH), the inflammatory phase of NAFLD, is linked to increased cardiovascular risk independent of the broad spectrum of risk factors of metabolic syndrome. Therefore, novel therapies are needed to inhibit the inflammatory liver damage that drives NAFLD. Hepatic macrophages (HMΦ’s), which include resident Kupffer cells and monocyte-derived macrophages, are the primary drivers of liver inflammation in both human and mouse models. In macrophages, chronic lipid exposure promotes pro-inflammatory polarization and the activation of pyroptosis via the NLRP3 inflammasome. While the role of the canonical pyroptosis pathway has been studied in NAFLD, the role of the newly discovered noncanonical (caspase-11/-Gasdermin-Ddependent) pathway has not been defined. Diet-induced NAFLD promoted hepatic steatosis and lobular inflammation in male WT mice. Caspase-11 deficiency decreases macrovesicular steatosis and total NAFLD Activity Score (NAS). High fat feeding promoted recruitment and activation of HMΦ in both Caspase-11 deficient (Casp11KO) and WT male mice, however, noncanonical pyroptosis (caspase-11 activity, surface Gasdermin-D, expression, liver IL-1β secretion) was ablated in HMΦs from Casp11KO mice. Bone marrow transplantation restored capacity for noncanonical pyroptosis in Casp11KO mice. RNAseq and microarray analysis revealed that lipid peroxidation and trained immunity mediate noncanonical pyroptosis in diet induced NALFD.

      Dai, Hai-Lung; Borguet, Eric; Sun, Yugang; Torchinsky, Darius H. (Temple University. Libraries, 2020)
      The development of efficient solar energy conversion devices has attracted much attention. Despite the fact that progress have been achieved, a fundamental understanding examining why efficiency can be improved remains elusive. For example, dye-sensitized solar cells (DSSC) exhibit high conversion efficiency when acetonitrile is used to prepare both the working electrode and the electrolyte. However, the mechanism explaining exactly how solvent influences device performance has not yet been systematically investigated. Another prominent example is the metal/semiconductor heterojunction systems. While it has been demonstrated that such mixed systems can significantly improve solar conversion efficiency, the mechanism of the electron dynamics driving these systems remains controversial. This stems in part from the fact that the experimentally deduced time constants, which are characteristic of such systems, are only ever extracted from phenomenological models and therefore cannot be assigned to specific physical processes. Ultimately, the development of a physical model is necessary to obtain an unambiguous physical picture of the solar conversion process. In this dissertation, the ultrafast nonlinear spectroscopic methods, second harmonic light scattering (SHS) and transient absorption (TA) spectroscopy, have been employed to study dye molecular adsorption and charge transfer dynamics in several solar energy conversion systems, including 1) DSSC, where solvent effects are investigated to understand why acetonitrile is the most effective solvent; 2) Ag/TiO2 heterostructure system, where a physical model is proposed to quantitively analyze the electron dynamics; 3) porphyrin/Ag/TiO2 nanocomposite, where we found there is no electron injection from porphyrin to TiO2 and plasmonic metal can enhance the porphyrin dye adsorption to improve the device efficiency. The propensity for surface adsorption of two related dyes, ortho-ethyl red (o-ER) and para-ethyl red (p-ER), onto TiO2 particles is studied with SHS. While p-ER readily adsorbs onto TiO2, o-ER does not. It is suggested that this difference is linked to the effects of the steric hindrance of the adsorbate. The influence of the solvent on the adsorption of p-ER onto TiO2 is also investigated. Of significance, p-ER can only chemically bond to the TiO2 surface in aprotic solvents, where adsorption free energy scales with solvent polarity. For protic solvents, preferential adsorption of the solvent shell ultimately prevents direct adsorption of p-ER onto the surface of TiO2. Likewise, solvent effects on charge transfer from p-ER to TiO2 are studied by TA. The electron injection rate is shown to be positively related to solvent polarity. Overall, highly polar aprotic solvents are shown to facilitate dye adsorption and electron injection, which helps improve the efficiency of DSSC devices. Ultrafast dynamics of plasmon-induced hot electrons from Ag to TiO2 nanorods are probed by TA. The observed transient signal, which corresponds to the lifetime of the optically generated electrons, is analyzed using a physical model including electron injection, relaxation, band edge annihilation, the surface to bulk diffusion, and back diffusion from the bulk to the surface. A ca. 13 fs electron injection time is deduced for Ag to TiO2, which is faster than that generated in Au and dyes. Additionally, the excited state exciton dynamics of a porphyrin J-aggregate are investigated and subsequently modeled. More rapid dynamics are found following aggregation of the porphyrin, which can be attributed to the inclusion of more efficient relaxation channels. However, no electron injection from the J-aggregate to TiO2 is observed. This likely stems from the negatively charged repulsion between the two components. Further, when the J-aggregate is introduced into an Ag/TiO2 system, optical excitation occurs predominantly in the J-aggregate. This stems either from direct excitation of the J-aggregate or indirect excitation through plasmon-induced resonant energy transfer from Ag. Our results indicate that plasmon can enhance the dye adsorption, which has great potential for designing more efficient plasmonic DSSC devices.
    • Nonlinear Control of Magnetic Signatures

      Biswas, Saroj K.; Ferrese, Frank; Bai, Li (Temple University. Libraries, 2015)
      Magnetic properties of ferrite structures are known to cause fluctuations in Earth's magnetic field around the object. These fluctuations are known as the object's magnetic signature and are unique based on the object's geometry and material. It is a common practice to neutralize magnetic signatures periodically after certain time intervals, however there is a growing interest to develop real time degaussing systems for various applications. Development of real time degaussing system is a challenging problem because of magnetic hysteresis and difficulties in measurement or estimation of near-field flux data. The goal of this research is to develop a real time feedback control system that can be used to minimize magnetic signatures for ferrite structures. Experimental work on controlling the magnetic signature of a cylindrical steel shell structure with a magnetic disturbance provided evidence that the control process substantially increased the interior magnetic flux. This means near field estimation using interior sensor data is likely to be inaccurate. Follow up numerical work for rectangular and cylindrical cross sections investigated variations in shell wall flux density under a variety of ambient excitation and applied disturbances. Results showed magnetic disturbances could corrupt interior sensor data and magnetic shielding due to the shell walls makes the interior very sensitive to noise. The magnetic flux inside the shell wall showed little variation due to inner disturbances and its high base value makes it less susceptible to noise. This research proceeds to describe a nonlinear controller to use the shell wall data as an input. A nonlinear plant model of magnetics is developed using a constant to represent domain rotation lag and a gain function to describe the magnetic hysteresis curve for the shell wall. The model is justified by producing hysteresis curves for multiple materials, matching experimental data using a particle swarm algorithm, and observing frequency effects. The plant model is used in a feedback controller and simulated for different materials as a proof of concept.
    • Nonlinear Optics in Non-Equilibrium Microplasmas

      Levis, Robert J.; Matsika, Spiridoula; Strongin, Daniel R.; Lyyra, A. Marjatta (Temple University. Libraries, 2011)
      This dissertation details the nature of subnanosecond laser-induced microplasma dynamics, particularly concerning the evolution of the electron temperature and concentration. Central to this development is the advent of a femtosecond four-wave mixing (FWM) spectroscopic method. FWM (in the form of coherent anti-Stokes Raman scattering (CARS)) measurements are performed on the fundamental oxygen vibrational transition. An analytical expression is provided that accounts for the resonant and nonresonant contributions to the CARS signal generated from the interaction of broadband pump and Stokes pulses. The inherent phase mismatch is also accounted for, resulting in quantitative agreement between experiment and theory. FWM is then used to measure the early-time electron dynamics in the noble gas series from He to Xe following irradiation by an intense (10^14 Wcm-2) nonresonant 80 fs laser pulse. An electron impact ionization cooling model is presented to determine the evolution of electron kinetic energies following ionization. Kinetic energies are predicted to evolve from > 20 eV to < 1 eV in the first 1.5 ns. The initial degree of ionization is determined experimentally via measurement of the Bremsstrahlung background emission, and modeled with a modified ADK theory based on tunnel ionization. Combined, these two descriptions account for the evolution of both the electron temperature and concentration and provide quantitative agreement with the FWM measurements. The model is further tested with measurements of the gas pressure and pump laser intensity on the electron dynamics. The FWM experiments are concluded with a qualitative discussion of dissociative recombination dynamics occurring in molecular microplasmas. The microplasma environment is used as a source for the generation of two-level systems in the excited state manifold of atomic oxygen and argon. These two-level systems are coupled using moderately intense ~1 ps near-infrared (and near-resonant) pulses, resulting in Rabi sidebands with unprecedentedly large shifts in excess of 90 meV. A time-dependent generalized Rabi-cycling model is developed to account for the time-dependence of the laser electric field and subsequently the Rabi frequency. The Rabi radiation is determined to be coherent and tunable (up to 200 meV), providing a new method for ultrashort pulse generation. The dependence of the spectral positions of the Rabi sidebands on laser intensity affords the opportunity to simultaneously determine the ratios of transition dipole moments for the states accessed.
    • Nonlinear PDE and Optical Surfaces Design

      Gutiérrez, Cristian E., 1950-; Mitrea, Irina; Mendoza, Gerardo A.; Hicks, R. Andrew (Temple University. Libraries, 2015)
      We introduce two models to design near field reflectors in R^3 that solve an inverse problem in radiometry, taking into account the inverse square law of irradiance. The problem leads to a Monge-Ampere type inequality. The surfaces in the first model are strictly convex and require to be far from the source to avoid obstruction. In the second model, the reflectors are neither convex nor concave and do not block the rays even if they are close to the source.