Now showing items 1-20 of 4905


      Sun, Yugang; Dobereiner, Graham; Voelz, Vincent; Wu, Xifan; Sun, Yugang (Temple University. Libraries, 2023)
      Alloy nanoparticles have been extensively studied for decades. However, the synthesis and characterization of alloy nanoparticles are still posing significant challenges, leading to an increasing demand for in situ characterization techniques. Small-angle X-ray scattering (SAXS) is a powerful method for structural analysis of nanoparticles. As the SAXS signal is essentially the Fourier transform of the electron distribution, it provides structural information for the entire ensemble of nanoparticles. The development of SAXS has been facilitated by significant advances in synchrotron X-ray sources and data processing methods, leading to the development of the 3D-SAXS method, which enables the reconstruction of the 3D structures of particles from SAXS profiles.Although SAXS has the potential to be a powerful tool for investigating the internal structures of alloy nanoparticles, its application is hindered by the challenges posed by polydispersity, which can cause smearing effects that complicate the geometry recovery process. This dissertation presents a novel approach to overcome the problem of polydispersity in SAXS data analysis, thus demonstrating the utility of SAXS in investigating the internal electron density distributions of alloy nanoparticles. In Chapter 2, the SharPy algorithm is introduced as a size-refocusing program that reduces the smearing effect caused by polydispersity in SAXS data. SharPy is based on a penalized iterative regression approach to fit the pair distance distribution function (PDDF) with an estimated size distribution. It can provide detailed information about the shape of nanoparticles from the smeared SAXS signal under various scenarios and conditions. Chapter 3 investigates the simulated SAXS profiles of AuAg core-shell nanoparticles with varying size distribution, core-shell ratio, and degrees of alloying. It demonstrates the capability of SAXS in observing the electron density distribution of AuAg core-shell structures. These findings provide insights into the potential of SAXS as a reliable method for investigating the internal structures of alloy nanoparticles. Chapter 4 focuses on synthesizing and characterizing AuAg nanoparticles. Their SAXS profiles and PDDF analysis demonstrate that SAXS can distinguish between homogeneous and core-shell nanoparticle structures. In this chapter, the SharPy algorithm is first-time applied to real experimental data, demonstrating its ability to reveal the core-shell structure from a polydisperse nanoparticle system. Chapter 5 investigates the evolution of alloying AuAg nanoparticles through a combination of SAXS/PDDF analysis, 3D reconstruction, and molecular dynamics (MD) simulation. The study presents the 3D electron density distribution of alloying AuAg nanoparticles. The 3D reconstruction with electron density mapping provides a straightforward visualization of the electron density distribution pattern of the alloying AuAg nanoparticles. The success of the SAXS experiment lies in the development of the 3D-SAXS pipeline, which involves the use of SharPy and 3D reconstruction programs, making 3D SAXS a promising alternative to electron microscopy for visualizing the morphology of nanoparticle systems.

      Kendall, Philip C.; McCloskey, Michael S.; Drabick, Deborah A.; Giovannetti, Tania; Fauber, Robert L.; Gosch, Elizabeth A. (Temple University. Libraries, 2023-08)
      Background: Anxiety and anxiety disorders are common among youth. Accommodation refers to ways in which parents/teachers/schools modify their behavior to alleviate a youth’s anxious distress. Although many anxious youths receive mental health services through schools, limited research has examined accommodation in the school setting and no study to date has examined the instruction of school-based mental health providers in evidence-based practices (EBPs) around accommodation. The present study compared two training conditions: problem-based learning (PBL) and training as usual (TAU) in their ability to increase (a) knowledge of, (b) attitudes/beliefs towards and (c) intended implementation of EBPs.Methods: Graduate students in school psychology (N=110) were randomized to workshops. Workshops used either PBL or didactic (TAU) strategies to educate trainees about EBPs for youth anxiety as they relate to accommodation. Trainees attended a 4-hour workshop and completed self-report measures assessing knowledge, attitudes and intended EBP use immediately before training, immediately after training and at 3-month follow-up. Results: Linear Mixed Models examined changes in outcome measures both across time and between training conditions. There were significant increases in workshop-specific knowledge and in beliefs about and intentions to use EBP from pre- to post-training. However, there were no significant differences between training conditions on outcome measures other than overall knowledge of EBPs. Pretraining instruction in, or attitudes about EBPs, did not significantly predict differential training outcomes.

      Jarcho, Johanna; Kendall, Philip C.; Olino, Thomas; Chein, Jason; Lerner, Matthew D.; Hackel, Leor (Temple University. Libraries, 2023)
      Social anxiety (SA) disorder is prevalent, chronic, and impairs quality of life. Typical onset occurs in early adolescence, when social relationships become more salient and complex. Difficulty learning from these newly complex, important interactions may potentiate SA. SA is associated with suboptimal adaptive learning rates in non-social and uncertain contexts. However, the impact of social contexts on learning during social interactions with peers in SA remains unknown. Enhanced SA symptoms while anticipating social feedback is associated with dysregulated engagement of neural circuits implicated in salience and reward processing, which are critical hubs for learning. Despite this overlap, the neural mechanisms that support learning from social feedback remain relatively unexplored in SA. To study the influence of social context and feedback on learning in SA, we paired computational modeling with a novel social interaction fMRI task to determine the extent to which peer value as well as the valence and predictability of peer feedback modulate the neural bases of social learning about peers and their relation to adolescent SA. Fifty-nine youth (age 10-15yrs) with a range of SA engaged in real-time social interactions with purported peers while undergoing an fMRI scan. Youth with clinically relevant SA learn to fear social interactions by emphasizing unexpected negative feedback, and discounting unexpected positive feedback, in predictably nice and unpredictable social contexts to rapidly adjust learning. More severe SA was associated with decreased engagement of salience, reward and cognitive control regions in predictably nice social contexts, and only engaged cognitive control regions in unpredictably mean social contexts. Results elucidate which aspects of the social context contribute to learning to fear social interactions on a neural and behavioral level that potentiate SA, which can inform specific intervention targets.

      Wengryniuk, Sarah E.; Dobereiner, Graham; Wang, Rongsheng; Li, Wei (Temple University. Libraries, 2023-05)
      The development of new strategies to access pyridinium salts are highly sought out due to their advantageous structures, which have diverse applications across materials science, biological processes, and organic synthesis. As synthetic intermediates, these scaffolds can be used as precursors to valuable piperidine derivatives and have recently emerged as important cross coupling handles for metal-catalyzed processes. Unfortunately, current methods to access pyridinium salts are limited; they require harsh conditions, rely on the presence of an amine functional handle, and are not amenable to diverse structural variation. In Chapter 1, a summary of various syntheses and the reactivity of pyridinium salts is provided. This dissertation provides new strategies to access pyridinium salts. The first method is via aminolactonization of alkenoic acids, resulting in 1° pyridinium salts (Chapter 2). The second method is a regioselective synthesis of 3-aminopiperidine salts via diamination of olefins (Chapter 3). Both methods are promoted by nitrogen-ligated hypervalent iodine reagents (N-HVIs). These novel class of reagents serve as “heterocyclic group transfer reagents,” incorporating diverse pyridinium salts under mild conditions and in excellent yields. Heterocyclic Group Transfer reactions have resulted in new classes of pyridinium salts that can be further functionalized via simple known methods to access diverse piperidine motifs, providing an innovative approach to substitution patterns that were previously challenging to synthesize. These strategies have also enabled pyridinium salts to be viewed as a synthetic platform for diversity-oriented amine synthesis. Chapter 4 will elaborate on the synthesis of different classes of 3-aminopiperidine motifs using hypervalent iodine reagents; these motifs have been previously synthesized using transition metal catalysis.
    • Reconstructing Contagion, Chronic Infirmity, and Healing in Early Modern Italy: Art and Architecture of Mal Francese in the Ambit of the Ospedali degli Incurabili Network

      Cooper, Tracy Elizabeth; Hall, Marcia B.; West, Ashley D. (Temple University. Libraries, 2023)
      This dissertation investigates art and architecture surrounding the early modern outbreak of what is commonly understood to be syphilis, focusing predominantly on the Italian peninsula and Sicily. Adopting the early modern term mal francese, I consider the processes through which contemporary notions of health and healing reconciled the identification and management of a novel contagion during the sixteenth and seventeenth centuries. More specifically, prioritizing historical perspectives of disease and intersecting socioeconomic factors, the cross-disciplinary approach of my dissertation demonstrates the cultural impact of the mal francese outbreak through art and architecture that framed the emerging contagion as a chronic infirmity.Primary accounts or literature, together with art, architecture, and urban space yield crucial insights for understanding how past cultures reconciled health crises. Despite its conspicuous symptoms and prevalence during the early modern period, mal francese has received markedly less attention in art historical scholarship compared to plague or leprosy. My dissertation takes advantage of this lacuna in the scholarship in order to examine how the epidemic outbreak was encountered and interpreted. The framework of my dissertation responds to intellectual traditions in the history of science and medicine, relying on early modern concepts of infirmity to analyze the art and architecture of mal francese in the ambit of the Ospedale degli Incurabili network. My Introduction (Chapter 1) examines the emergence of mal francese from the perspective of early modern medical theory. In addition to a review of scholarship, I establish context for studying representations of infirmity and healing, and charitable healthcare reform during the period. Chapter 2 investigates representations of mal francese across media during the long sixteenth century. My discussion considers diverse examples based on descriptive primary accounts of evolving symptoms to discern how the visual arts registered combined social and medical perceptions of the infirmity. I assert that these collective works disclosed recognition about the nature of mal francese as a chronic infirmity, which disproportionately impacted vulnerable members of society despite the realities of its indiscriminate transmission. In Chapter 3, I elucidate the implementation of medical care for mal francese though visual and material culture. Although deemed incurable, contemporary medical practice held that symptoms of mal francese could at least be managed in individuals. In this chapter, I examine art that supported adaptions in traditional therapeutic interventions and the introduction of novel remedies for the contagion. Chapter 4 draws a connecting thread through the dissertation regarding the broader impact of the outbreak on public health measures. I consider parallel developments in healing environments for mal francese relative to ongoing reforms for institutional models of charitable assistance. In particular, I discuss the form and function of the Ospedali degli Incurabili branches in Venice (1522), Naples (1519), and Palermo (1533). The demographic features and dynamics of those centers, as port cities, presented unique challenges for public health and welfare following the mal francese outbreak. Despite compelling links, and contrasts, my study is the first to examine the healing environments of these Incurabili hospital branches together. Founded during the sixteenth century, I examine how the hospitals ensured long term shelter and specialized care for the sick poor afflicted with mal francese. The dissertation then concludes with a brief Coda to synthesize key observations about the impact of mal francese in early modern art and architecture. This dissertation contributes to the field in three main ways. First, I demonstrate that representations of mal francese were highly context-dependent due to formal and iconographic affinities to other infirmities, and with respect to contexts of production and reception. The emphasis on depicted signs or symptoms shifted to convey visual information while providing reassurance, creating distance, or identifying those at the center of a health and welfare crisis as symbols of charitable assistance and subjects of medical care. Second, healing imagery associated with the infirmity didn’t depict mal francese patients recovering from illness, but rather focused on the means for managing its symptoms. In particular, the introduction of guaiacum as a foreign specific used to treat mal francese prompted inventive representational strategies to frame the remedy as a medical innovation and miraculous cure. Finally, access to that therapeutic regimen varied with respect to the medical marketplace, due to issues of cost and functional space. However, new charitable institutions began to facilitate treatment for the growing numbers of sick poor. The Ospedali degli Incurabili were the greatest consumers of guaiacum in the Italian peninsula and Sicily. Each of the branches I discuss developed to support greater accommodations for a growing patient population, facilities that offered specialized treatment for mal francese, and urban renovations guided by contemporary public health goals. This reflected a continuation of earlier models in healthcare reform towards greater medicalization and capacity, but the trend appeared to hasten in these centers following the foundation of the Ospedali degli Incurabili.

      Wattal, Sunil; Thatcher, Jason Bennett; D'Arcy, John P., 1975-; Moreira, Solon; Rytchkov, Oleg (Temple University. Libraries, 2023-08)
      The rapid development of technology and the associated new challenges such as cybersecurity risk triggered the rise of new digital upper echelons such as Chief Digital Officers (CDOs) or Chief Information Security Officers (CISOs). However, there is a lack of theoretical understanding and rigorous empirical examination regarding the impacts of emerging digital upper echelon roles on firm performance. This dissertation develops three essays that examine the rising digital upper echelons’ implications for firm innovation, cybersecurity strategies, and governance.The first essay examines the antecedents of CISO presence on the TMT and its consequences for firm innovation. We conduct a longitudinal empirical analysis using a unique dataset of S&P 1500 firms from several secondary sources. Our study shows that a firm's appointment of a CISO in TMT is positively influenced by the CISO presence in TMT of industry peers and their data breaches. Importantly, we find that CISO presence in TMT increases firms' innovation on average. The presence of a CISO in TMT with more experience in the same industry as the focal firm has a stronger effect on innovation, while CISOs in TMT with more experience in other industries only increase innovation when the firm's industry is not very turbulent. We also found that CISOs in TMT with a business or IT education have a stronger positive impact on firm innovation. This research is the first to assess the impact of CISO presence in TMT on non-security outcomes. We shed new light on the drivers of why firms appoint a CISO to TMT and how CISO presence in TMT impacts firm value beyond the security function. Our findings also provide managers with a nuanced understanding of how CISO backgrounds impact innovation and provide guidance for hiring CISOs who align with the firm's information management and innovation goals. The second essay focuses on how competing incentive systems (e.g., compensation) shape digital upper echelons and non-digital upper echelons impact on the firm's disclosure of data breaches in SEC fillings and the moderating role of board members' cybersecurity intensity on upper echelon members’ disclosure. We draw on the agency theory to develop a theoretical model considering the divergent priorities and goals of the digital and non-digital upper echelons involved. We conducted a longitudinal analysis of public firms that have experienced data breaches. Results demonstrate that increased digital upper echelons' compensation will lead to timelier SEC data breach notifications, whereas increased non-digital upper echelons' compensation will have the opposite effect. Board cybersecurity intensity weakens the positive impacts of digital upper echelons' compensation but amplifies the negative impacts of non-digital upper echelons' compensation on notification timeliness. Hence, our findings counter the view that cybersecurity experience on the board speeds up reporting of data breaches by upper echelons. This study also delineates the differences on incentive systems between digital and non-digital upper echelons in SEC data breach notifications. Our results provide managerial implications on how to incentivize firms to disclose data breaches in SEC in a timely manner. The third essay compares two different reporting structures of CDOs and CISOs: within-group reporting structure (i.e., report to IT heads) versus across-group reporting structure (i.e., report to non-IT heads). Since reporting structure needs to be aligned with firm strategic visions, we examine (1) how CDOs’ reporting structure and digital transformation jointly affect firm performance, and (2) how CISOs’ reporting structure and security awareness jointly affect firm performance. We conducted a longitudinal analysis using a unique dataset collected from multiple sources. Our results demonstrate that compared with within-group reporting structure, CDOs reporting to non-IT heads weakens the positive relationship between digital transformation and the firm’s prospective performance (i.e., market-to-book ratio of assets). However, CISOs reporting to non-IT heads weakens the negative relationship between security awareness and the firm’s retrospective performance (i.e., operational incomes). Overall, our results highlight the advantages of CDOs’ within-group reporting structure and CISOs’ across-group reporting structure. This research contributes to our understanding of how CDOs’ and CISOs’ reporting structure aligns with firm strategic visions in shaping firm performance. Our findings offer implications to business managers on designing reporting structures and governing emerging IT executives. Overall, this three-essay dissertation enriches our understanding of the impacts of rising digital upper echelons and effective ways to govern these emerging top management roles.

      Beglar, David; Nemoto, Tomoko; Tono, Yukio; Sick, James (Temple University. Libraries, 2023-08)
      Data-driven learning is a sub-discipline of corpus linguistics that makes use of the analyses and tools of corpus linguistics in foreign and second language classroom (Johns, 1991; Johns & King, 1991). With this approach, learners become researchers rather than passive recipients of language rules (Johns, 1991). This study was an investigation of the impact of this approach as a form of written corrective feedback for in-service teachers of English participating in an online writing course at a teacher training institute in Japan. Data-driven learning is commonly utilized in conventional, face-to-face classrooms, or computer lab settings in which there is close direction from the instructor on how to interpret the output of a corpus query. The purpose of this study was to investigate how data-driven learning can be implemented in a blended online environment by providing training to develop the participants’ corpus competence (Charles, 2011; Flowerdew, 2010), which is defined as the ability to interpret data obtained from querying a corpus. This competence has been associated with becoming familiar with corpus methods, which include interpreting concordances, and in turn can aid in accurately repairing writing errors. This training, while initially presented in a face-to-face session at the beginning of the course, was sustained with support from resources on the course’s Moodle website and my comments in Microsoft Word documents. In addition, I applied a fine-grained approach to the analysis of the to examine the quality of participants’ interpretation of concordances. The mixed method triangulation convergence design (Creswell & Plano Clark, 2007, 2011) used in this study was based on data from four sources to examine the effectiveness of data-driven learning in an online environment as well as to observe how the participants interpreted concordances. One data set involved an analysis of the participants’ responses in drafts of their own writing to concordance-based feedback. The participants were given a prefabricated concordance, which was a concordance I generated. That concordance was attached to an error in the participants’ document and the participants used the information provided by the concordance to repair their writing error. The resulting data set, which contains the concordance, along with before and after comparisons of the writers’ repairs, shows how the participants’ interpretations of concordances aided the repairs. With the evidence of several trials over the course of four writing assignments, it was possible to see how the participants used the supplied concordance to repair their writing errors and in turn revealed their degree of corpus competence. A second data set obtained from think-aloud protocols from select participants was utilized to reveal how they interpreted the concordance during an error-repair task. This data revealed what kind of thought processes or noticing that occurred in this task. A third piece of evidence was derived from data obtained from the Moodle website via log files and other resources such as online documents and training quizzes. The purpose was to document which resources the participants accessed relating to data-driven learning training to investigate if those resources aided in their development of corpus competence. The fourth piece of evidence was a quiz developed online to compare the participants with a standard set of items. The quiz was used to investigate which participants successfully or unsuccessfully interpreted the concordances. This instrument, which was analyzed with the Rasch model, allowed for further comparison between the participants’ skill of interpreting concordances. These four data sources were triangulated and in the final analysis cross-referenced to examine how data-driven learning can be successfully applied in a blended online learning environment and how the training of corpus competence aided the learners in interpreting the concordances.
    • The Demise of the Picaresque: Dividual Narratives of the Neoliberal Marketplace in Brazil and Argentina (1881-2000)

      Shellhorse, Adam Joseph; Pueyo Zoco, Víctor; Lorenzino, Gerardo; Widder, Nathan, 1970- (Temple University. Libraries, 2023-08)
      The Demise of the Picaresque: Dividual Narratives of the Neoliberal Marketplace in Brazil and Argentina (1881-2000) examines the connections between economics, Jewish conversos (or new Christians), mechanisms of desire, and literature from a transatlantic and Luso-Hispanic perspective. Taking as a point of reference the Iberian Golden Age (16th and 17th centuries) and the influential figure of the pícaro from the picaresque novels of the time —a roguish figure living in the margins of society— this project questions the nature, conditions, and problems of renowned writers living in Golden Age times, only to interrogate the reenacting of this genre in Latin America centuries later by way of two Brazilian and two Argentine authors. In so doing, this study announces a post-picaresque aesthetic that formally hearkens back to the rogues of old while establishing a new paradigm from which to observe the neoliberal subject in the information age.
    • Productivity consequences of Foreign Direct Investment Connectivity

      Mudambi, Ram, 1954-; Gaur, Ajai S., 1977-; Moreira, Solon; Tandon, Vivek, 1964-; Tae, Chung Won (Jennifer) (Temple University. Libraries, 2023-08)
      The primary aim of this dissertation was to examine the implications of conceptualizing Foreign Direct Investment (FDI) as a multilateral and multilevel phenomenon. The first research study in the dissertation examines the implication of a multilateral perspective on FDI in our assessment of the relationship between inward FDI and the economic growth and development of the host countries. This study showed that inward FDI positively impacts the economic growth of the host countries in both the short and long term. The second research study focused on conceptualizing FDI as a multilevel phenomenon. The fundamental premise of this chapter was to explicitly acknowledge that even though the implications of FDI can be observed at the aggregate level, such as host countries, as was the case in the first research study, these consequences emerge from the decisions of the individual firms. Furthermore, the findings of this research study demonstrate that different levels of FDI are interconnected but have different implications for the firm’s performance. Drawing upon the existing literature, two considered levels were location-based FDI networks and interfirm collocation networks. Empirical analyses showed that location-based networks are characterized by agglomeration and lead to positive production externalities, while competitive interactions characterize interfirm collocation networks and lead to negative production externalities. Consequently, increasing agglomeration is associated with increasing production output, and increasing competitive interaction is associated with decreasing production output of the firms. In the last research study, we considered how different network externalities, as explicated in the previous chapter, impact the firms' strategic decision-making. This study shows that firm membership in the country-of-origin network helps them make better decisions, while membership in interform collocation networks worsens their decision-making abilities.

      Srivastava, Joydeep; Wang, Yang; Kumar, Subodha; Wattal, Sunil (Temple University. Libraries, 2023-08)
      Effects of marketing mix tools, such as price promotions and digital advertising, are dynamic and long-term. Yet marketing literature has mainly focused on their immediate and short-term effects. Marketing Mix changes consumers' state, such as expectations and beliefs, and the changed state affects consumers' subsequent behaviors and responses to marketing stimuli and treatment, which may cause unintended consequences and generate important marketing opportunities as well. In Essay 1, we uncover the perils of tensile discounts (e.g., maximum discounts such as "up to 60% off") by examining their effects on store visits and purchases. Through a series of studies and using a multi-method approach including empirical data analysis, quasi-field experiment, numerical simulations, and controlled lab studies, we find that despite the initial efficacy in shaping consumer discount expectations and stimulating store visits, a maximum discount (vs. a minimum discount such as "starting at 20% off" or a range discount such as "20% off to 60% off") could reduce consumer purchases in many conditions. There is thus a need to balance the outcomes of the two stages and choose the optimal tensile discount under different discount distributions to maximize store sales. In Essay 2, we investigate how digital platforms leverage curation source (algorithm or human) advertising to promote depth or breadth selling and best sequence these two types of advertising to further improve advertising effects. Through a survey study and a field experiment, we find that consumers have a lay belief about the competitive advantages of algorithms and humans that algorithms (humans) generate personalized (novel) recommendations, and importantly, they consider and purchase products similar (new) to their previous preferences when receiving such advertising. Moreover, the complementarity between depth and breadth selling can be best leveraged in sequential advertising by the initial breadth selling amplifying the subsequent depth selling effectiveness. Thus, a carefully-sequenced hybrid advertising can help cultivate consumers’ ever-renewing interests and consumption.
    • A Integrative Investigation of Urban Animals and the Ecosystem Services They Provide in Cities

      Behm, Jocelyn E.; Freestone, Amy; Sewall, Brent J.; Warren, Paige S. (Paige Shannon) (Temple University. Libraries, 2023-08)
      Urban landscapes are complex social-ecological systems comprising human and natural elements and their interactions. A key priority for research in these landscapes is understanding how humans affect the presence and abundance of wild organisms and how those organisms, in turn, provide ecosystem services that affect humans. In this dissertation, I use two field studies to understand the ecosystem services provided by urban animals in green spaces across Philadelphia and in a third study I investigate geographic bias in where urban animals have been studied in the United States. For the first study, I use a functional trait approach to examine how urban bird communities respond to landscape- and local-scale habitat and how community composition corresponds to potential ecosystem services. I show that the landscape-scale context of a green space has a stronger influence on species’ abundances than local-scale habitat. As a result, the effect traits associated with cultural and regulating ecosystem services varied strongly along the landscape-scale gradient of urbanization. Local-scale variation in habitat had little effect. The importance of landscape-scale habitat in driving the supply of bird-mediated ecosystem services underscores the importance of regional urban planning for green spaces.In the second study, I use a field experiment to determine the drivers of an understudied ecosystem service – the removal of littered food waste by birds and squirrels. I recorded food removal activity by animals in green spaces across Philadelphia and found that Eastern gray squirrels (Sciurus carolinensis) are the main driver of this service. With increased squirrel abundance, removal level is higher and is both initiated and completed more quickly. This service is also context dependent, such that more food is removed in urban parks and picnic areas, where animals are presumably accustomed to consuming anthropogenic foods. These results highlight the importance of animal behavior, and factors that affect it, for the supply of ecosystem services. In my third study, I take a geographic approach to identifying bias in the study of animals in urban landscapes. Our knowledge of urban ecosystems in the United States is based on hundreds of field studies and thousands of individual field sites, but the distribution of these sites has never been examined. I reviewed the literature and mapped field sites to assess geographic bias in the location of urban ecology field sites. At a national scale, I find that urban ecologists tend to work in larger cities, especially those that are less socioeconomically vulnerable (more affluent). I also find that the social-ecological attributes of the neighborhoods in which ecologists work depends on the framing of their study as well as the focal taxa and functional groups studied. Overall, the neighborhoods where marginalized people live are an underexplored segment of the urban landscape. This is the first study to identify geographic biases in urban ecology field sites and provides a basis for future urban ecology research that produces knowledge applicable to all cities and neighborhoods.

      Wang, Rongsheng; Nicholson, Allen W.; Voelz, Vincent; Blass, Benjamin E. (Temple University. Libraries, 2023-08)
      Cyclization reactions play an important role in synthesizing a significant number of small molecule scaffolds for various purposes, including drug discovery. However, the application of cyclization reactions in the modifications of biomolecules in a single step is still limited. This dissertation reports a stereoselective thiomorpholine ring formation reaction to site-selectively modify N-terminal cysteines of unprotected peptides or proteins in a single step. We showed that α-fluoroketone molecules afford the cyclization reaction with the beta amino thiol group of N-terminal cysteine. Both chemo and stereo-selectivity of this reaction have been studied using 2D NMR analyses. Cysteine located at the Nterminal of a short protein (VHP protein) has been modified site-selectively with a fluorescein isothiocyanate (FITC) containing an α-fluoroketone linker to demonstrate the applicability of this reaction in modifying biomolecules. This chemistry has the potential to generate homogeneous and stable antibody-drug conjugates (ADCs) for the treatment of cancer. This dissertation also demonstrates a fluorine-thiol displacement reaction (FTDR) to synthesize various macrocyclic and stapled peptides, which renders medicinally privileged peptides with improved biological properties such as binding affinities and cell membrane permeability. The cyclization of fluoroacetamide containing peptides with benzenedimethane thiol linkers enhances peptides' alpha helicity. These FTDR stapled peptides exhibit better cellular uptake compared to the classic ring-closing metathesis (RCM) stapled peptides. Compared to the proteoglycan-aided cell penetration by peptides stapled with RCM, the preliminary mechanistic studies of our FTDR-stapled peptides revealed that our thiolated linkers allowed peptides to enter cells in multiple pathways. Taken together, our FTDR-based stapling approach may provide a novel class of cell-permeable peptides that might open a new window to probe intracellular targets. This dissertation reports another cyclization reaction between hydrazine and carbamate, synthesized from 7-hdyroxy coumarin derivatives. We demonstrate that the secondary nitrogen of hydrazine is much more reactive than the primary nitrogen for intramolecular cyclization reactions. Hydrazine affords urea bonds upon the substitution of a coumarin moiety of carbamates to generate 6 or 7 membered cyclic scaffolds. The exocyclic free amine might allow facile generation of a library of compounds. In addition, further optimization of this reaction might allow using these hydrazine containing molecules in monitoring the real-time activity of histone deacetylases (HDACs).

      Kumar, Subodha; Roy, Abhishek; Mudambi, Ram, 1954-; Chen, Yiwei (Temple University. Libraries, 2023-08)
      Companies face strategic trade-offs and contractual challenges in collaborative and competitive settings within the framework of institutional theory. Institutional theory focuses on the influence of formal and informal rules and norms that shape organizational behavior. This dissertation encompasses three distinct domains: co-creation in a multi-vendor setting, luxury e-commerce, and social media marketing. Drawing from the lens of institutional theory, the research explores how collaboration, competition, and isomorphism influence decision-making and outcomes in these domains. Each domain presents unique business problems, which are formulated into research questions, supported by relevant theories and literature, and addressed through analytical or empirical models. The findings from each chapter provide valuable managerial insights. In the first chapter, the focus is on collaborative value co-creation. The growing complexity of consulting, new product development, and information technology projects has led firms to increasingly adopt the strategy of collaborative value co-creation with their vendors. By analyzing the strategic interactions among a client, a primary vendor, and a potential secondary vendor, the research uncovers the trade-offs and dynamics that arise in these complex co-creation environments. Building on institutional theory, the study highlights how collaborative relationships in co-creation differ from traditional sourcing models. It reveals that the inclusion of a secondary vendor, even with lower efficiency, can be strategically beneficial for the client in certain scenarios. Conversely, there are situations where involving a more efficient second vendor may not be advantageous. These findings shed light on the institutional factors influencing decisions in collaborative environments. In the second chapter, I investigate the realm of luxury e-commerce and explore the pricing strategies adopted by luxury brands on multi-brand platforms. The study investigates the competition dynamics between luxury brands and e-commerce platforms.It addresses the optimal pricing strategies for luxury brands and examines whether allowing platform discounts aligns with institutional pressures. Luxury brands face a difficult trade-off between offering online discounts and maintaining their high-end brand image, which is often associated with price consistency across channels. On the other hand, e-commerce platforms struggle to assert control over pricing, which affects their ability to thrive in the market. Contrary to conventional wisdom, the research demonstrates that participating in platform discounts can be a viable strategy for luxury brands, even for high-valued products. Moreover, the analysis reveals the potential for pricing coordination across different channels. By considering market conditions and customer preferences, the study identifies factors that impact decision-making and profitability, contributing to the understanding of institutional influences in luxury e-commerce. In the third chapter, the research explores social media marketing in the context of the luxury fashion industry, focusing on the influence of isomorphism between competing brands. Grounded in institutional theory, the study employs machine learning techniques to analyze data from the social media platform of two prominent luxury brands. By examining content features and engagement rates, the research investigates the existence of isomorphic behavior among competing brands. The findings highlight similarities in content structures, approaches, and messaging strategies, indicative of isomorphism. However, the study also emphasizes the importance of differentiation in content strategy to create unique and distinctive brand identities. These insights offer valuable implications for firms seeking to enhance their social media marketing strategies within the institutional context. Overall, this dissertation integrates the perspectives of institutional theory across three interconnected chapters. By examining collaboration, competition, and isomorphism in co-creation, luxury e-commerce, and social media marketing, my research provides a comprehensive understanding of how institutional factors shape decision-making and outcomes in these domains. The findings contribute to the existing literature on institutional theory, offering practical insights for managers in navigating the complexities of collaborative and competitive environments, while aligning with prevailing institutional pressures. Additionally, the research opens avenues for future exploration into the interplay between institutions and strategic decision-making in various business contexts.

      Tam, Vincent; Caricchio, Roberto; Gallucci, Stefania; Elrod, John W.; Pisetsky, David S. (Temple University. Libraries, 2023-08)
      SLE is a chronic autoimmune disorder marked by immune dysregulation and inflammation. Multiple mitochondrial dysfunctions, such as increased mitochondrial reactive oxygen species (mROS), depolarized membrane potential, altered morphology, and changes in energy production, were observed in patients with systemic lupus erythematosus (SLE), suggesting that mitochondrial function plays a role in lupus pathogenesis. Calcium is an essential regulator of mitochondrial functions, and when macrophages become polarized, their metabolism is reprogrammed based on their phenotypes. The connection between mitochondrial calcium mobilization and lupus remains unclear. In this study, we explored the expression and function of the mitochondrial calcium uniporter (MCU) in monocytes/macrophages in lupus pathogenesis. We examined the ex vivo gene expression profiles of human renal biopsies with nephropathies, SLE whole blood, peripheral blood mononuclear cells (PBMCs), and mouse renal macrophages, identifying a decrease in MCU-related genes in Lupus nephritis and other inflammatory nephropathies. We also found that the expression of MCU-related genes significantly decreased in monocytes and macrophages stimulated with LPS and also upon M1/2 polarization, both from healthy controls and patients with SLE. Lastly, we generated hematopoietic and endothelial cell specific MCU knockout mice and used a pristane-induced lupus model to test in vivo the role of MCU in lupus development. Interestingly, there was no significant difference in disease severity between MCU knockout mice and wild-type mice, indicating that the absence of MCU did not improve nor worsen lupus pathology in mice. Since the LPS-induced down-regulation of MCU- related genes, found in human cells, was not consistently reproducible in murineiii macrophages, these results suggest a species-specific regulation of MCU-related genes in innate immunity. Macrophage plays a crucial role in both initiating and remitting inflammation. Imbalanced polarization of macrophage population has been identified in lupus patients. To understand the contribution of macrophage polarization in lupus, we conducted RNA sequencing on peripheral blood mononuclear cells (PBMCs) from healthy controls and SLE patients to assess gene expression changes related to macrophage polarization. Our findings reveal a differential regulation of 324 genes in SLE patients, primarily involved in inflammatory processes and type I interferon signaling, providing a molecular snapshot of the disease. Specifically, increased expression of M1 macrophage polarization associated genes was identified in SLE patients. Correlation analysis further elucidated the relationship between M1 polarization, lupus disease manifestations, complement activation, and disease activity, highlighting a robust interplay between these factors. Additionally, a strong correlation between the interferon-I signatures and M1 polarization was observed, indicating a profound interplay in SLE pathology. In conclusion, these results provide valuable insights into the reduction of mitochondrial function during monocyte/macrophage activation and in lupus nephritis and pro-inflammatory orientation of peripheral blood monocytes. Although a causal link between MCU, macrophage polarization and lupus remain unclear, these results support further research to fully understand the complex relationship between mitochondrial function, calcium mobilization, macrophage polarization, and lupus pathogenesis.
    • Contributions of Sleep Quality and Dissociation to Attenuated Positive Psychotic Symptom Severity

      Ellman, Lauren M.; Murty, Vishnu; Alloy, Lauren B.; Giovannetti, Tania; McCloskey, Michael S.; Olino, Thomas (Temple University. Libraries, 2023)
      Sleep disturbances have been observed across the entire psychosis spectrum. Research has begun to focus on the clinical high risk (CHR) period for psychosis, as the presence of sleep disturbance can be examined separately from the effects of antipsychotic medication and is potentially a risk factor for later psychosis. Several studies have demonstrated a link between sleep disturbance and worsened positive symptoms in CHR individuals. However, sleep disturbance is not unique to the psychosis-spectrum and is well documented in individuals experiencing dissociation. Transdiagnostically, dissociation has been associated with poorer outcomes and reduced treatment response. Despite the established associations between these variables, their respective contributions to positive symptom severity in the CHR period has not yet been characterized. This study examined the separate and combined contributions of sleep quality and dissociation on positive symptom severity in a cross-sectional sample of individuals identified as being at CHR for psychosis. Hierarchical linear regression was conducted to examine the independent and additive influence of sleep quality and dissociation on unusual thought content, suspiciousness, and perceptual abnormalities. Finally, logistic regression was used to determine if sleep quality and dissociation increase odds of a CHR diagnosis. Analyses of indirect effects revealed a significant indirect effect of sleep disturbance on perceptual abnormalities through dissociation in the CHR group. In addition, both sleep disturbance and dissociation significantly contributed to a model predicting to perceptual abnormalities, also in the CHR group. In the total sample, both sleep quality and dissociation significantly increased the odds of a CHR diagnosis. These results suggest that dissociation plays a significant role in the sleep-attenuated positive psychotic symptom relationship in the CHR period, and as a result, could be a modifiable treatment target in these individuals.
    • Basis Risk in Variable Annuities

      Moenig, Thorsten; Grace, Martin Francis, 1958-; Collier, Benjamin; Viswanathan, Krupa S.; Rytchkov, Oleg (Temple University. Libraries, 2023-08)
      This dissertation provides a comprehensive and practical analysis of basis risk in the U.S. variable annuity market and examines effective fund mapping strategies to mitigate the level of basis risk while controlling for the associated transaction costs. Variable annuities are personal savings and investment products with long-term guarantees that expose life insurers to extensive financial risks. Liabilities associated with VA guarantees are the largest liability component faced by U.S. life insurers and have raised concerns to VA providers and regulators. And the hedging performance of these guarantee liabilities is impeded by the existence of basis risk. I look into 1,892 registered VA-underlying mutual funds and two VA separate accounts to estimate the basis risk faced by U.S. VA providers at the individual fund level and the separate account level. To evaluate the degree to which basis risk can be mitigated, I consider various proxy instrument sets and assess different variable selection models. The LASSO regression is shown to be most effective at identifying the most suitable (combination of) mapping instruments that minimize basis risk, compared to other test-based and screening-based models. I supplement it with the Sure Independence Screening (SIS) procedure to further limit the number of instruments requested in the hedging strategies, and modify it by introducing the diff LASSO regression to restrict the changes in instrument allocations across rebalancing periods and, therefore, control for transaction costs. I show that VA providers can reduce their exposure to basis risk by applying data analytic techniques in their mapping process, by hedging with ETFs instead of futures contracts, and through diversification at the separate account level. Combining the traditional fund mapping method with the machine learning algorithm, the proposed portfolio mapping strategy is efficient at reducing basis risk in VA separate accounts while controlling for the tractability and transaction costs of the mapping and hedging procedure, and is practical to incorporate newly-developed VA funds, as well as the varying compositions of separate accounts. Overall, this study presents that U.S. VA providers have the ability to mitigate basis risk to a greater extent than the limited literature on this topic has suggested.

      Thatcher, Jason B.; Ayabakan, Sezgin; Wattal, Sunil; Roth, Philip L. (Temple University. Libraries, 2023-08)
      With many kinds of personal information becoming available online in the past decades, this dissertation addresses the personal, managerial, and societal implications of personal information online that used to be private in the past. Essay One (Chapter 2) investigates the role of social information (such as names and profile photos) in racial discrimination against Blacks using a correspondence method on an online rental housing platform. It examines whether Blacks with non-Black-sounding names are discriminated against, compared to those with Black-sounding names or Whites, when race is signaled through profile photos. In addition, it studies whether building less complete profiles (e.g., using pseudonyms or not presenting profile photos) impartially hurts Blacks and Whites. Essay Two (Chapter 3) compares involuntary discovery and voluntary disclosure of personal information (invisible stigma) in a hiring context. It examines how the two modes of learning about job applicants’ social media differently influence hiring outcomes. Essay Three (Chapter 4) looks at party identity as antecedents of online privacy decisions for public safety such as personal data for contact tracing and crime detection. Additionally, it investigates two interventions that promote online privacy decisions for public safety when party identity is salient: deemphasis on party identity and recategorization as national identity. Overall, this dissertation contributes to the literature on information systems, social psychology, and economics by highlighting the role of digital technology in enabling a greater depth of identity disclosure and discovery and thus changing the landscape of perception and decision-making today.

      Pollack, Mark A., 1966-; Vander Wielen, Ryan J.; Deeg, Richard, 1961-; Karreth, Johannes (Temple University. Libraries, 2023-08)
      The UN Security Council (UNSC) is a crucial international decision-making body that deals with a range of conflicts requiring consideration. However, its formal issue consideration has remained stagnant, with only a few new conflicts being added to the list. This project aims to investigate the conditions under which the Council members opt for informal governance settings instead of formal ones to address global crises and argues that the official UNSC agenda is not solely shaped by the preferences of powerful states but is influenced by the Council's operational methods. To explore this, the project combines two strands of scholarship on informal governance in international organizations and introduces a rational choice framework to analyze the factors influencing governance choices. The study employs a multi-method approach, including a multinomial regression model and a case study analysis of the Rohingya crisis in Myanmar from 2017 to 2022. The findings suggest that member states select the most suitable meeting type based on Council homogeneity, information availability, and issue urgency while considering their preference for formal consideration. The Council's yearly changing membership and fluctuations in information availability prompt states to strategically shift issue consideration between formal and informal, public and private settings. Contrary to criticisms, the Council does not overlook specific crises but often discusses urgent matters informally. Should member states' preference for formal issue consideration align with issue urgency that the Council shifts to formal meetings at the horseshoe table. This project sheds new light on the functioning of the UNSC and contributes novel insight into how member states' meeting choices early in the policy-making process significantly influence agenda-setting and decision-making outcomes.
    • Asymmetry In Operational Efficiency and Managerial Ability Benchmarks

      Basu, Sudipta, 1965-; Byzalov, Dmitri; Krishnan, Jagan; Kumar, Subodha (Temple University. Libraries, 2023-08)
      Standard empirical models of operating efficiency (OE) and managerial ability (MA) assume a symmetric linear relation of OE and MA with firm performance. However, OE and MA metrics are likely to respond faster to a demand decrease than a demand increase due to cost stickiness and respond faster to negative returns than to positive returns due to accounting conservatism. As predicted, I find large asymmetries in the behavior of OE and MA measures. OE and MA in levels (changes) are 2.4 (1.4) times and 1.5 (1.6) times more sensitive to demand decreases than demand increases. Similarly, OE and MA levels (changes) are 1.7 (1.5) times and 3.6 (2.3) times more sensitive to negative returns than to positive returns. The incremental explanatory power of modeling asymmetry in OE and MA levels (changes) is 20.9% (39.5%) and 263.3% (27.6%), measured as incremental adjusted R2. Cross-sectionally, asymmetry in OE and MA varies with the determinants of cost stickiness: (1) asset intensity and (2) employee intensity. Moreover, the degree of asymmetry also varies with the determinants of accounting conservatism: (1) book-to-market value of equity, (2) leverage, and (3) market capitalization. In addition, demand decline (i.e., cost stickiness) and bad news (i.e., accounting conservatism) during prior and successive periods have an incremental impact on the asymmetry in OE and MA. The standard models of OE and MA do not control for these correlated-omitted variables or incorporate the cost stickiness and accounting conservatism asymmetries, which yield biased measurements and render incorrect regression estimates and inferences.
    • Validation of Smartphone-Derived Digital Phenotypes for Cognitive Assessment in Older Adults

      Giovannetti, Tania; Drabick, Deborah A.; Smith, David V.; Alloy, Lauren B.; Tan, Chiu C.; Barnett, Ian J. (Temple University. Libraries, 2023)
      As the global burden of dementia continues to plague our healthcare system, efficient, objective, and sensitive tools to characterize cognition and detect underlying neurodegenerative disease increasingly are needed. Digital phenotyping relies on passive, continuous collection of smartphone sensor data during everyday life to measure activities, behaviors, and mood. The present study explored the feasibility, acceptability, and validity of a digital phenotyping protocol as a novel method for characterizing cognition and function among a heterogeneous group of older adults. Validation analyses were based on a recently proposed conceptual model explaining activity level and variability as a function of cognitive ability level. Exploratory analyses aimed to examine and account for a range of participant and environmental factors that may be associated with digital phenotyping data. A total of 22 participants ages 65 - 81 years with either healthy cognition or mild cognitive impairment (MCI) used their own personal smartphones naturally during a four-week study period while a secure software application unobtrusively and continuously obtained Global Positioning System (GPS)-based movement trajectories. Participants completed gold-standard neuropsychological measures and questionnaires of everyday function, mood, and mobility habits at a baseline visit intended to evaluate construct validity. In-depth informed consent and a comprehension of consent quiz also were administered at baseline to inform feasibility of explaining digital phenotyping study procedures to older adults. Debriefing questionnaires were completed at the end of the study period, including questions pertaining to acceptability. Correlation analyses showed that measures of GPS activity and variability were positively associated with validators of cognition, everyday function, mood, and mobility habits. Potential confounding factors included season of study participation, unexpected health changes, and highest lifetime household annual income, whereas participant demographics such as education, sex, and race were not significantly associated with GPS features. Metrics on study withdrawal, comprehension of consent, and satisfaction ratings at study completion revealed good feasibility and acceptability. In sum, digital phenotyping shows promise as a feasible, acceptable, and potentially valid method to efficiently and objectively assess cognition, function, and mood in a cohort of older adults. Future studies will benefit from incorporating these preliminary findings and testing predictions in larger, more diverse cohorts both cross-sectionally and over time in longitudinal designs.