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Tracking The Summary Statistics In Long-Term Memory
Get PDFDecades of research have demonstrated humans’ extraordinary ability to extract summary statistics across individual experiences. Less is known about how exactly the items contribute to the summary statistics and how the relationship between memory for the items and memory for the summary statistics evolves and changes over time. I propose that memory of summary statistics that are initially extracted from individual instances starts to guide memory for individual items over time, and not all items contribute to the summary statistics equally. Sources of item distinctiveness influence the summary statistics extraction in terms of the contribution of each item and the accuracy of summary statistics. The three empirical chapters enlighten our understanding of summary statistics extraction in long-term memory by bridging fields ranging from perception and memory to emotion and motivation
Constructing Authenticity: Images Of Japan In Photograph Albums, 1862-1901
No full textAfter Japan lifted the policy restricting international trade in 1854, many travelers visited Japan for the first time. Photographs and photograph albums became accessible and affordable souvenirs for these visitors, who came mainly from Europe and North America. Numerous photograph prints were sold both individually and as albums, and these images reached around the world. These photographs were one of the most popular visual representations of Japan to be taken abroad during the Meiji period (1868-1912), and they still exist in large numbers today in libraries and museums in and outside Japan. This dissertation examines these albums to consider how they shaped ideas about Japan and Japanese art for both Japanese and foreign audiences.
Looking at the album as an object, this study will be the first to consider these export photographs in the format they were commonly sold and stored. First, I discuss the album as a format that personally connects the owner with the images from the trip to Japan. Then I examine the photographs inside the album to consider the stories told inside the souvenir albums. Close inspection of the photographs inside the album presents how the export photographs represented multifaceted views and cultures of Japan. Another part of an album, the lacquer covers, lavishly decorate the album. The covers used the Japanese traditional craft technique for a new purpose, to impress foreign audiences. This dissertation offers a new perspective in the field of Meiji period art by considering the album as an important part of redefining Japanese art and culture in the Meiji period
Tissue Responses To Environmental Challenges
No full textAnimals must protect themselves from environmental challenges to survive and reproduce. However, the mechanisms that underlie adaptive tissue responses to (1) environmental cold temperatures and (2) ingested toxin exposure remain poorly understood. In the first section of this thesis, I find that transient cold exposure leads to sustained transcriptional and metabolic adaptations in brown adipose tissue, which are critical for an improved thermogenic response to secondary cold encounter. A primary thermogenic challenge triggers the delayed induction of a lipid biosynthesis program even after cessation of the original stimulus, which protects from subsequent exposures. By combining single-nucleus RNA sequencing, spatial transcriptomics, and immunofluorescence imaging, I discover that this lipogenic response is carried out by a distinct subpopulation of brown adipocytes that is localized along the perimeter of classical Ucp1high brown adipocytes. The protective effect of the lipogenic program is associated with the production of acyl carnitines, and supplementation of acyl carnitines recapitulates improved secondary cold responses even in the absence of lipogenesis. Overall, these findings highlight the importance of heterogenous brown adipocyte populations for “thermogenic memory” in the setting of repeated cold exposure, which may have implications for therapeutic efforts leveraging short-term thermogenesis to counteract the hypercaloric state of obesity. In the second section of this thesis, I hypothesized that the small intestine has intrinsic responsiveness to the protein GDF15 which plays a role in the response to ingested toxins. GFRAL forms the receptor for GDF15, and currently it is thought that GFRAL is exclusively expressed by neurons in the hindbrain. By combining single-nucleus RNA sequencing of the enteric nervous system with whole mount immunofluorescence I discover that a subpopulation of enteric neurons in the small intestine express the Gfral receptor and characterize their anatomical location in the myenteric plexus. Further, I discover that Gfral-expressing enteric neurons share a similar transcriptional signature to Gfral-expressing neurons in the hindbrain. Given that GFRAL is a promising therapeutic target for the treatment of human diseases ranging from cancer cachexia to obesity, the discovery of Gfral-expressing enteric neurons may inform the development of GFRAL-targeting therapeutic approaches
Essays In Macro-Finance
Get PDFIn the first chapter, I show that the long-term decrease in the nominal short rate since the 1980s contributed to a decline in banks\u27 supply of business loans, firm investment and new firm creation, and an increase in banks\u27 real estate lending. The driving force behind these relationships was the shift in banks’ funding mix from time deposits (CDs) to savings deposits, which was caused by the decrease in the nominal rate. I show that banks finance business lending with time deposits because of their matching interest-rate sensitivity and liquidity. A lower nominal rate reduces the spread on liquid deposits (e.g., savings deposits), leading households to substitute towards them and away from illiquid time deposits. In response to an outflow of time deposits, banks cut the supply of business loans and increase their price. The decrease in business lending leads to reduced investment at bank-dependent firms and a lower entry rate of firms in industries that are highly reliant on external funding. I document these relationships both in the aggregate, and in the cross-section of banks, firms and geographic areas. For identification, I exploit cross-sectional variation in banks\u27 market power and business credit data. I develop a general equilibrium model which captures these relationships and shows that the transmission mechanism I document is quantitatively important.
In the second chapter, joint with Caterina Mendicino, Kalin Nikolov, Juan Rubio-Ramirez and Javier Suarez, we examine optimal capital requirements in a quantitative general equilibrium model with banks exposed to non-diversifiable borrower default risk. Contrary to standard models of bank default risk, our framework captures the limited upside but significant downside risk of loan portfolio returns. This helps to reproduce the frequency and severity of twin defaults: simultaneously high firm and bank failures. Hence, the optimal bank capital requirement, which trades off a lower frequency of twin defaults against restricting credit provision, is 5pp higher than under the standard default risk models which underestimate the impact of borrower default on bank solvency.
In the third chapter, joint with Martina Jasova and Caterina Mendicino, we show that a reduction in lender of last resort (LOLR) policy uncertainty positively affects bank lending and propagates to investment and employment. We exploit a unique policy that reduced uncertainty regarding the availability of future LOLR funding for banks as a quasi-natural experiment. Using micro-level data on banks, firms and loans in Portugal, we generate cross-sectional variation in banks\u27 exposure to uncertainty and find that the size of the haircut subsidy - the gap between private market and central bank security valuations - plays a key role in the propagation of the shock to lending and the real economy
Negotiating Between Shell And Paper: Wampum Belts As Agents Of Religious Diplomacy
Get PDFIn a dialogue between the material and the textual, can objects speak over texts? This project examines nine devotional wampum belts produced as cross-cultural mediators between Catholic ecclesiastics and Indigenous people in northeastern North America between the seventeenth and nineteenth centuries. Following Haudenosaunee, Huron-Wendat, Abenaki, and Anishinaabe epistemologies, wampum belts have been considered as both symbols of Native American and First Nations sovereignty, and as non-human beings doted with agency and willpower. When Indigenous Christians sent wampum belts to religious communities in France, Belgium, and Italy, these objects embodied diplomatic requests presented to Christian saints worshipped at these sites. Did these wampum belts function as independent diplomatic agents, without the presence of Indigenous interpreters? If so, what were these belts meant to do? I suggest that there may be heretofore unexamined messages, embedded in the material and documentary record, that reveal the agency and potency of these objects. Closer engagements with wampum materiality can offer insights that are missing from earlier historical studies of missionary-Indigenous relations. To discern this, I examined construction techniques that may reveal Indigenous makers’ agency in articulating political demands. I conducted archival research and re-examined historical translations, while consulting with the Indigenous communities in Canada who created these wampum belts, to assess how wampum messaging impacts the consciousness of humans around it. These diverse sources illuminate the transfers of agency that take place during wampum diplomacy, showing the embodied innovations and continuities that allowed these materials to “speak” across space and time. These wampum belts constitute an alternative archive of both Indigenous and missionary strategies. The objects and associated papers show savvy Indigenization of Catholic stories and practices to secure new alliances and territories, at the same time that religious orders recorded different understandings of these relationships in French colonial archives. When these belts and papers have survived side by side in collections, they have continued to mediate various relationships, the most significant being between generations of Indigenous peoples who relate to their ancestors through them
Advancements In Modeling And Simulating Nonadiabatic Dynamics In Electrochemical Systems
Get PDFCurrent methods for modeling electron transfer (ET) dynamics in electrochemical systems rely on boundary condition based methods that often obfuscate any nonadiabatic effects. However, these nonadiabatic effects can play critical roles in many key electrochemical systems, such as ET events coupled to proton transfer, or systems where ET occurs between metal adsorbed redox species and the metal. In this dissertation we present new methods and algorithms for modeling and simulating electrochemical systems exhibiting nonadiabatic effects. First, we examine whether electron friction dynamics can be used in lieu of surface hopping generally for nonadiabatic dynamics. We find that electronic friction is only applicable in specific situations, and that in general a broadened classical master equation solved with surface hopping must be applied in the weak molecule-metal coupling limit. Next, we outline a surface hopping approach for modeling sweep voltammetry experiments, and show a technique for mapping multidimensional, diffusional electrochemical systems to reduced, lower dimensional systems. This surface hopping approach is used to study proton coupled electron transfer (PCET), whereby nuclear quantum effects are incorporated through an explicit proton coordinate. Finally, we present a spatially grid-free algorithm for simulating the above electrochemical systems (including systems where inner-sphere effects are included, such as adsorption), and also demonstrate its computational efficacy in comparison to current simulation techniques common in the field of electrochemistry
Graphene Biosensors For The Detection Of Disease Biomarkers
No full textIn an effort to diagnose and monitor disease progression, many healthcare specialists have moved towards using diagnostic tests capable of detecting biomolecules associated with particular diseased conditions. These molecules are referred to as biomarkers, and their concentrations in human samples can be used to gain information about a particular disease state. Many diagnostic tests capable of quantifying biomarker concentrations must be outsourced to diagnostic laboratories run by specialized technicians and health scientists. As a result, these tests are expensive to run and can have extensive delays in reporting results to patients. In an effort to create more sensitive and efficient diagnostic tests, scientists have begun exploring alternative methods of biomarker detection using all electronic nanomaterial based biosensors. These sensors are cost effective, easily fabricated, and capable of detecting low concentrations of biomarkers in small (\u3c200 ul) sample volumes. Graphene based biosensors, created from graphene field effect transistors (GFETs), are once such sensor type. GFETs are all electronic devices that can be created by traditional photolithography. The graphene used in these devices is often synthesized by chemical vapor deposition (CVD) and functionalized with probe molecules specific for various biomarkers of interest. By quantifying the concentration of these biomarkers, GFETs have the potential to be used as point of care devices to both diagnose and monitor the progression of various diseases. This will allow for better treatment of diseased conditions by enabling specialists to detect small changes in their patient’s condition before obvious symptoms develop. This work discusses advancements towards creating point of care devices from GFETs by lowering the limit of detection of the nucleic acid biosensors to the few copy level, optimizing the detection system to perform measurements in complex solution, lowering the required sample volumes for sensing from 250 uL to 10 uL, using mis-matched lengths of probes and targets to create faster more sensitive biosensing devices, and performing sensing experiments to detect biomarkers for HIV-1 type B, SARS-COV-2, and Parkinson’s disease
Rust And Ferns: Work, Value, And The Politics Of Everyday Security In Kudremukh, South India
No full textThis dissertation is a historical and ethnographic study of the politics of everyday security in the Kudremukh region of southern India, where a state iron-ore mine was decommissioned after activists cited threats to the area’s ecology. Building on security as the basic desire for ongoing economic and ecological stability, I examine how individuals and communities enact environmental projects and the search for livelihood in zones where mineral resources overlap with biodiversity. The dissertation analyzes—and yet qualifies—the ways in which material and discursive forms of work in such contexts come to be presented with ethical urgency. Drawing on twenty-one months of ethnographic fieldwork across the Kudremukh, Mangalore, Bengaluru regions in India, interviews with mining employees, residents, conservationists, environmentalists, and biologists, and a wide range of primary materials including speeches, protest letters, and historical newspapers, the project illustrates how efforts to secure stability take the form of theorizing work as making value in ways that are not exhausted by the logics of commodity or exchange. Such enactments of value, I argue, rely on reconceptions of landscape, extraction, eco-tourism, multispecies relations, conservation, and biodiversity. The project makes two interventions at this crossing of discourses: 1) It offers an analysis of environmental security derived from the ethical work of diverse actors and their dynamic relations with non-human life in such post-extraction sites 2) Attending to the dynamics of class, caste, and gender, the project shows how the quest for secure futures, even as it reinforces older forms of hierarchy and exclusion, brings into being new ecologies and new social mobilities
What Does Not Kill You Makes You Stronger: The Effects Of An Overcoming Adversity Identity On Performance And Burnout
Get PDFThe limited organizational scholarship on past adversity has characterized it as something to cope with, positing that how past adversity is perceived is key to employees’ coping effectiveness (Nurmohamed et al., 2021; Stephens et al., 2015; Vogel & Bolino, 2020). Conversely, lay theory suggests that “what does not kill you makes you stronger.” Through this dissertation, I aim to provide empirical evidence for this claim in an organizational setting. To do so, I draw on positive identity growth theorizing (Maitlis, 2009; 2020) to empirically examine the organizational benefits of identity growth after experiences of overcoming adversity. In doing so, I introduce a new concept to the organizational behavior literature, an “overcoming adversity identity,” which is when an experience of hardship, whether singular or continuous, has been redeemed in the eyes of the person with that experience, thereby becoming a positive part of that person’s identity. Through two longitudinal studies and one randomized experimental intervention, I find promising evidence that having a stronger overcoming adversity identity is associated with interpersonal, intrapersonal, and intellectual character enrichment (the tripartite model of character; Park et al., 2017). I also find some evidence that suggests that this character enrichment, in turn, is positively related to extra-role performance and in-role performance, and negatively related to burnout. Implications and future directions are discussed. In conclusion, this dissertation provides preliminary empirical evidence to suggest that indeed, what does not kill you can make you stronger
The Digital Bahdala: Recoding National Humiliation Across Postrevolutionary Lebanon And Egypt
Get PDFThis dissertation analyzes three transnational social media scandals in the postrevolutionary contexts of Egypt and Lebanon. It offers these as cases of digital bahdala, or the didactic performative mode and state of humiliation, embarrassment, or shame which utilize the affordances and imaginaries of digital media platforms. It examines the rhetorical techniques, performances, and symbols used by transnational publics on three different social media platforms around these scandals. It finds that audiences engage in recoding, or the cultivation of alternative feeling states, to repair national imaginaries which are exposed as incompatible with a cosmopolitanism which was once promised. It also finds that activists can leverage the digital bahdala and its reliance on digital affordances meet demands for national accountability in exploitative labor conditions. In doing so, it offers digital bahdala as a diagnostic for a national belonging which is threatened but which carries the potential for repair