Quantum Gate and Quantum State Preparation through Neighboring Optimal Control

Successful implementation of fault-tolerant quantum computation on a system of qubits places severe demands on the hardware used to control the many-qubit state. It is known that an accuracy threshold Pa exists for any quantum gate that is to be used for such a computation to be able to continue for an unlimited number of steps. Specifically, the error probability Pe for such a gate must fall below the accuracy threshold: Pe < Pa. Estimates of Pa vary widely, though Pa ∼ 10−4 has emerged as a challenging target for hardware designers. I present a theoretical framework based on neighboring optimal control that takes as input a good quantum gate and returns a new gate with better performance. I illustrate this approach by applying it to a universal set of quantum gates produced using non-adiabatic rapid passage. Performance improvements are substantial comparing to the original (unimproved) gates, both for ideal and non-ideal controls. Under suitable conditions detailed below, all gate error probabilities fall by 1 to 4 orders of magnitude below the target threshold of 10−4. After applying the neighboring optimal control theory to improve the performance of quantum gates in a universal set, I further apply the general control theory in a two-step procedure for fault-tolerant logical state preparation, and I illustrate this procedure by preparing a logical Bell state fault-tolerantly. The two-step preparation procedure is as follow: Step 1 provides a one-shot procedure using neighboring optimal control theory to prepare a physical qubit state which is a high-fidelity approximation to the Bell state |β01⟩ = 1/√2(|01⟩ + |10⟩). I show that for ideal (non-ideal) control, an approximate |β01⟩ state could be prepared with error probability ϵ ∼ 10−6 (10−5) with one-shot local operations. Step 2 then takes a block of p pairs of physical qubits, each prepared in |β01⟩ state using Step 1, and fault-tolerantly prepares the logical Bell state for the C4 quantum error detection code.

ENZYME-FREE UBIQUITIN LIGATION. FROM NATIVE CHEMICAL LIGATION AND SPIN LABELING TO DIMERIZATION BY INTER-UBIQUITIN MIMICKING LINKAGE AND PH-DEPENDENT CONFORMATIONAL SWITCH

The delicate balance between the production and disposal of proteins is vital for the changes required in the cell to respond to given stimulus. Ubiquitination is a protein modification with a range of signaling outcomes when ubiquitin is attached to a protein through a highly ordered enzymatic cascade process. Understanding ubiquitination is a growing field and nowadays the application of chemical reactions allows the isolation of quantitative materials for structural studies. Therefore, in this dissertation it is described some of these suitable chemical methodologies to produce an isopeptide bond toward the polymerization of ubiquitin bypassing the enzymatic control with the purpose of showing if these chemical modifications have a direct impact on the structure of ubiquitin. First, the possibility of incorporating non-natural lysine analogs known as mercaptolysines into the polypeptide chain of Ubiquitin was explored when they were attached to ubiquitin by native chemical ligation at its C terminus. The sulfhydryl group was used for the attachment of a paramagnetic label to map the surface of ubiquitin. Second, the condensation catalyzed by silver nitrate was used for the dimer assembly. In particular, the main focus was on examining whether orthogonal protection and deprotection of each monomer have an impact on the reaction yield, since the synthetic strategy has been previously attempted successfully. Third, the formation of ubiquitin dimers was approached by building an inter-ubiquitin linkage mimicking the isopeptide bond with two approaches, the classic disulfide exchange as well as the thiol-ene click reaction by thermal initiation in aqueous conditions. After assembling the dimeric units, they were studied by Nuclear Magnetic Resonance, in order to establish a conformational state profile which depends on the pH conditions. The latter is a very important concept since some ligands have a preferred affinity when the protein-protein hydrophobic patches are in close proximity.

Language-based Techniques for Practical and Trustworthy Secure Multi-party Computations

Secure Multi-party Computation (MPC) enables a set of parties to collaboratively compute, using cryptographic protocols, a function over their private data in a way that the participants do not see each other's data, they only see the final output. Typical MPC examples include statistical computations over joint private data, private set intersection, and auctions. While these applications are examples of monolithic MPC, richer MPC applications move between "normal" (i.e., per-party local) and "secure" (i.e., joint, multi-party secure) modes repeatedly, resulting overall in mixed-mode computations. For example, we might use MPC to implement the role of the dealer in a game of mental poker -- the game will be divided into rounds of local decision-making (e.g. bidding) and joint interaction (e.g. dealing). Mixed-mode computations are also used to improve performance over monolithic secure computations. Starting with the Fairplay project, several MPC frameworks have been proposed in the last decade to help programmers write MPC applications in a high-level language, while the toolchain manages the low-level details. However, these frameworks are either not expressive enough to allow writing mixed-mode applications or lack formal specification, and reasoning capabilities, thereby diminishing the parties' trust in such tools, and the programs written using them. Furthermore, none of the frameworks provides a verified toolchain to run the MPC programs, leaving the potential of security holes that can compromise the privacy of parties' data. This dissertation presents language-based techniques to make MPC more practical and trustworthy. First, it presents the design and implementation of a new MPC Domain Specific Language, called Wysteria, for writing rich mixed-mode MPC applications. Wysteria provides several benefits over previous languages, including a conceptual single thread of control, generic support for more than two parties, high-level abstractions for secret shares, and a fully formalized type system and operational semantics. Using Wysteria, we have implemented several MPC applications, including, for the first time, a card dealing application. The dissertation next presents Wys*, an embedding of Wysteria in F*, a full-featured verification oriented programming language. Wys* improves on Wysteria along three lines: (a) It enables programmers to formally verify the correctness and security properties of their programs. As far as we know, Wys* is the first language to provide verification capabilities for MPC programs. (b) It provides a partially verified toolchain to run MPC programs, and finally (c) It enables the MPC programs to use, with no extra effort, standard language constructs from the host language F*, thereby making it more usable and scalable. Finally, the dissertation develops static analyses that help optimize monolithic MPC programs into mixed-mode MPC programs, while providing similar privacy guarantees as the monolithic versions.

EFFECTS OF AGING ON MIDBRAIN AND CORTICAL SPEECH-IN-NOISE PROCESSING

Older adults frequently report that they can hear what they have been told but cannot understand the meaning. This is particularly true in noisy conditions, where the additional challenge of suppressing irrelevant noise (i.e. a competing talker) adds another layer of difficulty to their speech understanding. Hearing aids improve speech perception in quiet, but their success in noisy environments has been modest, suggesting that peripheral hearing loss may not be the only factor in the older adult’s perceptual difficulties. Recent animal studies have shown that auditory synapses and cells undergo significant age-related changes that could impact the integrity of temporal processing in the central auditory system. Psychoacoustic studies carried out in humans have also shown that hearing loss can explain the decline in older adults’ performance in quiet compared to younger adults, but these psychoacoustic measurements are not accurate in describing auditory deficits in noisy conditions. These results would suggest that temporal auditory processing deficits could play an important role in explaining the reduced ability of older adults to process speech in noisy environments. The goals of this dissertation were to understand how age affects neural auditory mechanisms and at which level in the auditory system these changes are particularly relevant for explaining speech-in-noise problems. Specifically, we used non-invasive neuroimaging techniques to tap into the midbrain and the cortex in order to analyze how auditory stimuli are processed in younger (our standard) and older adults. We will also attempt to investigate a possible interaction between processing carried out in the midbrain and cortex.

Between Nation and State: Albanian Associations from Ottoman Origins to a Communist Party, 1880 - 1945

This dissertation addresses the broader antecedents of the Communist Party of Albania (CPA) as one of a number of associations whose experience was central to Albanian political history. This long experience dates back to the informal national associations formed in the Ottoman Empire of the late nineteenth century. The dissertation examines the role of these associations which, pursuing language rights and political representation through imperial state reforms, set a pattern that struggled to connect nation and state, rather than asserting the territorial demands for a nation-state familiar across the region. Starting out in the Ottoman Empire, but then maturing in the Albanian diaspora in Romania, Bulgaria, Egypt and the United States, this dissertation shows politically significant processes of longer-term adaptation that created informal associations as institutional structures able to channel collective action. It then traces the reframing of these patterns through their destruction in the Balkan Wars and the First World War to the emergence of communist associations in the interwar period and beyond. This dissertation is a sustained study that traces long-term Ottoman imperial political legacies in the Albanian successor state. The story of the associations, based on hitherto unexamined archival documents, shows that the Albanians possessed a far greater capacity for political mobilization that previously acknowledged by historians. Moreover, the dissertation successfully challenges the conventional wisdom that portrays the Albanians as irreparably divided along sectarian and regional faultlines. It finds that Albanian national activism was civic in character rather than ethnic as elsewhere in the Balkans. The Albanians fought to remain within a multinational framework because this afforded them political security, social advancement and potential economic growth. In the late Ottoman period, this political objective was manifested in the acceptance of the supranational imperial order whereas during the Second World War, in the aspiration to become members of the Comintern internationalist movement. Another important find, is the newly-discovered evidence concerning the founding of the CPA and its wartime conduct as an organization created and led by the Albanians themselves, albeit with Yugoslav ideological assistance under the transnational umbrella of the Comintern.

EXPLORING THE EFFECTS OF THE RELATIONSHIP BETWEEN SCHOOL CHARACTERISTICS, TEACHER CHARACTERISTICS, ADMINISTRATIVE SUPPORT, AND SCHOOL CLIMATE ON VOLUNTARY INTRA-DISTRICT TEACHER MIGRATION

This quantitative research study utilized a binary logistic regression in a block design to investigate exogenous and endogenous factors influencing a teacher’s decision to make an intra-district move. The research focused on the following exogenous factors: classroom characteristics (size of class, percent minority, percent of students with an individualized education plan, and percent of students that are English language learners) and teacher characteristics (experience and gender). The following endogenous factors were examined: direct administrative influence (administrative support, rules enforced, school vision, teacher recognition, and job security) and indirect administrative influence (school climate, student misbehavior, parental support, materials, staff collaboration). The research was conducted by using information available from the National Center for Educational Statistics, the SASS from 2011-2012 and TFS from 2012-2013. The 2012-2013 Teacher Follow-up Survey identified 60 teachers who made a voluntary intra-district move. Results illustrate there is a statistically significant relationship between percentage of English Language Learners and overall job satisfaction and teachers choosing to make an intra-district move.

Observed Social Problem Solving and Friendship Quality in Children with a Traumatic Brain Injury

Children who have experienced a traumatic brain injury (TBI) are at risk for a variety of maladaptive cognitive, behavioral and social outcomes (Yeates et al., 2007). Research involving the social problem solving (SPS) abilities of children with TBI indicates a preference for lower level strategies when compared to children who have experienced an orthopedic injury (OI; Hanten et al., 2008, 2011). Research on SPS in non-injured populations has highlighted the significance of the identity of the social partner (Rubin et al., 2006). Within the pediatric TBI literature few studies have utilized friends as the social partner in SPS contexts, and fewer have used in-vivo SPS assessments. The current study aimed to build on existing research of SPS in children with TBI by utilizing an observational coding scheme to capture in-vivo problem solving behaviors between children with TBI and a best friend. The current study included children with TBI (n = 41), children with OI (n = 43), and a non-injured typically developing group (n = 41). All participants were observed completing a task with a friend and completed a measure of friendship quality. SPS was assessed using an observational coding scheme that captured SPS goals, strategies, and outcomes. It was expected children with TBI would produce fewer successes, fewer direct strategies, and more avoidant strategies. ANOVAs tested for group differences in SPS successes, direct strategies and avoidant strategies. Analyses were run to see if positive or negative friendship quality moderated the relation between group type and SPS behaviors. Group differences were found between the TBI and non-injured group in the SPS direct strategy of commands. No group differences were found for other SPS outcome variables of interest. Moderation analyses partially supported study hypotheses regarding the effect of friendship quality as a moderator variable. Additional analyses examined SPS goal-strategy sequencing and grouped SPS goals into high cost and low cost categories. Results showed a trend supporting the hypothesis that children with TBI had fewer SPS successes, especially with high cost goals, compared to the other two groups. Findings were discussed highlighting the moderation results involving children with severe TBI.

HOLDING HANDS WHILE PARTING WAYS: EXAMINING ALLIANCE TREATY RENEGOTIATION

This study investigates the renegotiation of security alliances, specifically the structural conditions surrounding their revision. Although the field of international relations offers a rich discussion of the formation and violation of alliance treaties, few scholars have addressed the reasons why alliance members amend security obligations. After the formation of an alliance, a member may become dissatisfied owing to changes in the external and domestic security environments. A failure to address this discontent increases the risk of alliance breakdown. Members manage their alliance relationship through a negotiation process or intra-alliance bargaining in the search for a new arrangement that can endure. Factors that help to show commitment to the alliance and communicate a set of feasible solutions are crucial if members are to find a mutually acceptable arrangement. By taking these factors into account, allies are more likely to revise an existing treaty. Examining a set of bilateral alliances dating from 1945 to 2001, this research demonstrates that public requests for renegotiation compel allies to change the status quo. It is found that alliance-related fixed assets and the formation of external alliances increase the likelihood of treaty revision, though institutionalization of an alliance does not help to resolve interest divergence. In addition, this study examines the strategy of delay in intra-alliance bargaining. Allies may postpone a dispute by ignoring it while working to maintain the alliance. Tension among allies thus increases, but the alliance endures. I examine three alliances in order to illustrate this renegotiation process. Among these, the Anglo-Japanese alliance demonstrates two successful renegotiations that prolonged a wavering alliance relationship; the Sino-Soviet alliance is an example of failure owing to the lack of substantive cooperation; and the US-Taiwan alliance during the 1970s demonstrates successful use of a strategy of delay that appeases a dissatisfied member.

HIV Reverse Transcriptase Fidelity And Inhibition Are Modulated By Divalent Cations In A Concentration-Dependent Manner In Vitro

Human immunodeficiency virus (HIV) rapidly evolves through generation and selection of mutants that can escape drug therapy. This process is fueled, in part, by the presumably highly error prone polymerase reverse transcriptase (RT). Fidelity of polymerases can be influenced by cation co-factors. Physiologically, magnesium (Mg2+) is used as a co-factor by RT to perform catalysis, however, alternative cations including manganese (Mn2+), cobalt (Co2+), and zinc (Zn2+) can also be used. I demonstrate here that fidelity and inhibition of HIV RT can be influenced differently, in vitro, by divalent cations depending on their concentration. The reported mutation frequency for purified HIV RT in vitro is typically in the 10-4 range (per nucleotide addition), making the enzyme several-fold less accurate than most polymerases. Paradoxically, results examining HIV replication in cells indicate an error frequency that is ~10 times lower than the error rate obtained in the test tube. Here, I reconcile, at least in part, these discrepancies by showing that HIV RT fidelity in vitro is in the same range as cellular results, in physiological concentrations of free Mg2+ (~0.25 mM). At low Mg2+, mutation rates were 5-10 times lower compared to high Mg2+ conditions (5-10 mM). Alternative divalent cations also have a concentration-dependent effect on RT fidelity. Presumed promutagenic cations Mn2+ and Co2+ decreases the fidelity of RT only at elevated concentrations, and Zn2+, when present in low concentration, increases the fidelity of HIV-1 RT by ~2.5 fold compared to Mg2+. HIV-1 and HIV-2 RT inhibition by nucleoside (NRTIs) and non-nucleoside RT inhibitors (NNRTIs) in vitro is also affected by the Mg2+ concentration. NRTIs lacking 3'-OH group inhibited both enzymes less efficiently in low Mg2+ than in high Mg2+; whereas inhibition by the “translocation defective RT inhibitor”, which retains the 3ʹ-OH, was unaffected by Mg2+ concentration, suggesting that NRTIs with a 3ʹ-OH group may be more potent than other NRTIs. In contrast, NNRTIs were more effective in low vs. high Mg2+ conditions. Overall, the studies presented reveal strategies for designing novel RT inhibitors and strongly emphasize the need for studying HIV RT and RT inhibitors in physiologically relevant low Mg2+ conditions.

THE EFFECT OF SCHOOL CLIMATE (STUDENT AND TEACHER ENGAGEMENT) ON STUDENT PERFORMANCE

Title of Dissertation: THE EFFECT OF SCHOOL CLIMATE (STUDENT AND TEACHER ENGAGEMENT) ON STUDENT PERFORMANCE Kenneth L. Marcus, Doctor of Education, 2016 Directed By: Dr. Thomas Davis, Assistant Professor, Education Policy and Leadership, Department of Teaching and Learning, Policy and Leadership This quantitative research study was designed to compute correlations/relationships of student engagement and student achievement of fifth grade students. Secondary information was collected on the relationship of FARMS, type of school, hope, and well-being on student achievement. School leaders are charged with ensuring that students achieve academically and demonstrate their ability by meeting identified targets on state and district mandated assessments. Due to increased pressure to meet targets, principals implement academic interventions to improve student learning and overlook the benefits of a positive school climate. This study has provided information on the impact of school climate on student achievement. To conduct this study, the researcher collected two sets of public fifth grade data (Gallup Survey student engagement scores and DSA reading, mathematics, and science scores) to determine the relationship of student performance and school climate. Secondary data were also collected on teacher engagement and the percentage of students receiving FARMS to determine the effect on students. The findings from this study reinforced the belief that school climate can have a positive effect on student achievement. This study contributed quantitative data about the relationship between school climate and school achievement.

Integrating Environmental Justice and Social-Ecological Resilience for Successful Adaptation to Climate Change: Lessons from African American Communities on the Eastern Shore of the Chesapeake Bay

This research concerns the conceptual and empirical relationship between environmental justice and social-ecological resilience as it relates to climate change vulnerability and adaptation. Two primary questions guided this work. First, what is the level of resilience and adaptive capacity for social-ecological systems that are characterized by environmental injustice in the face of climate change? And second, what is the role of an environmental justice approach in developing adaptation policies that will promote social-ecological resilience? These questions were investigated in three African American communities that are particularly vulnerable to flooding from sea-level rise on the Eastern Shore of the Chesapeake Bay. Using qualitative and quantitative methods, I found that in all three communities, religious faith and the church, rootedness in the landscape, and race relations were highly salient to community experience. The degree to which these common aspects of the communities have imparted adaptive capacity has changed over time. Importantly, a given social-ecological factor does not have the same effect on vulnerability in all communities; however, in all communities political isolation decreases adaptive capacity and increases vulnerability. This political isolation is at least partly due to procedural injustice, which occurs for a number of interrelated reasons. This research further revealed that while all stakeholders (policymakers, environmentalists, and African American community members) generally agree that justice needs to be increased on the Eastern Shore, stakeholder groups disagree about what a justice approach to adaptation would look like. When brought together at a workshop, however, these stakeholders were able to identify numerous challenges and opportunities for increasing justice. Resilience was assessed by the presence of four resilience factors: living with uncertainty, nurturing diversity, combining different types of knowledge, and creating opportunities for self-organization. Overall, these communities seem to have low resilience; however, there is potential for resilience to increase. Finally, I argue that the use of resilience theory for environmental justice communities is limited by the great breadth and depth of knowledge required to evaluate the state of the social-ecological system, the complexities of simultaneously promoting resilience at both the regional and local scale, and the lack of attention to issues of justice.

CHARACTERIZATION OF POLYUBIQUITIN CHAINS BY MASS SPECTROMETRY

The work outlined in this dissertation will allow biochemists and cellular biologists to characterize polyubiquitin chains involved in their cellular environment by following a facile mass spectrometric based workflow. The characterization of polyubiquitin chains has been of interest since their discovery in 1984. The profound effects of ubiquitination on the movement and processing of cellular proteins depend exclusively on the structures of mono and polyubiquitin modifications anchored or unanchored on the protein within the cellular environment. However, structure-function studies have been hindered by the difficulty in identifying complex chain structures due to limited instrument capabilities of the past. Genetic mutations or reiterative immunoprecipitations have been used previously to characterize the polyubiquitin chains, but their tedium makes it difficult to study a broad ubiquitinome. Top-down and middle-out mass spectral based proteomic studies have been reported for polyubiquitin and have had success in characterizing parts of the chain, but no method to date has been successful at differentiating all theoretical ubiquitin chain isomers (ubiquitin chain lengths from dimer to tetramer alone have 1340 possible isomers). The workflow presented here can identify chain length, topology and linkages present using a chromatographic-time-scale compatible, LC-MS/MS based workflow. To accomplish this feat, the strategy had to exploit the most recent advances in top-down mass spectrometry. This included the most advanced electron transfer dissociation (ETD) activation and sensitivity for large masses from the orbitrap Fusion Lumos. The spectral interpretation had to be done manually with the aid of a graphical interface to assign mass shifts because of a lack of software capable to interpret fragmentation across isopeptide linkages. However, the method outlined can be applied to any mass spectral based system granted it results in extensive fragmentation across the polyubiquitin chain; making this method adaptable to future advances in the field.

Studying the Causes and Consequences of Internal Labor Migration Using Survey and Administrative Data Sources

This dissertation comprises three chapters. The first chapter motivates the use of a novel data set combining survey and administrative sources for the study of internal labor migration. By following a sample of individuals from the American Community Survey (ACS) across their employment outcomes over time according to the Longitudinal Employer-Household Dynamics (LEHD) database, I construct a measure of geographic labor mobility that allows me to exploit information about individuals prior to their move. This enables me to explore aspects of the migration decision, such as homeownership and employment status, in ways that have not previously been possible. In the second chapter, I use this data set to test the theory that falling home prices affect a worker’s propensity to take a job in a different metropolitan area from where he is currently located. Employing a within-CBSA and time estimation that compares homeowners to renters in their propensities to relocate for jobs, I find that homeowners who have experienced declines in the nominal value of their homes are approximately 12% less likely than average to take a new job in a location outside of the metropolitan area where they currently reside. This evidence is consistent with the hypothesis that housing lock-in has contributed to the decline in labor mobility of homeowners during the recent housing bust. The third chapter focuses on a sample of unemployed workers in the same data set, in order to compare the unemployment durations of those who find subsequent employment by relocating to a new metropolitan area, versus those who find employment in their original location. Using an instrumental variables strategy to address the endogeneity of the migration decision, I find that out-migrating for a new job significantly reduces the time to re-employment. These results stand in contrast to OLS estimates, which suggest that those who move have longer unemployment durations. This implies that those who migrate for jobs in the data may be particularly disadvantaged in their ability to find employment, and thus have strong short-term incentives to relocate.

KINESIN MOTOR PROTEINS ARE ESSENTIAL FOR MALE GAMETOPHYTE DEVELOPMENT IN MARSILEA VESTITA

The male gametophyte of the semi-aquatic fern, Marsilea vestita, produces multiciliated spermatozoids in a rapid developmental sequence that is controlled post-transcriptionally when dry microspores are placed in water. Development can be divided into two phases, mitosis and differentiation. During the mitotic phase, a series of nine successive division cycles produce 7 sterile cells and 32 spermatids in 4.5-5 hours. During the next 5-6 hours, each spermatid differentiates into a corkscrew-shaped motile spermatozoid with ~140 cilia. This document focuses on the role of motor proteins in the regulation of male gametophyte development and during ciliogenesis. In order to study the mechanisms that regulate spermatogenesis, RNAseq was used to generate a reference transcriptome that allowed us to assess the abundance of transcripts at different stages of development. Over 120 kinesin-like sequences were identified in the transcriptome that represent 56 unique kinesin transcripts. Members of the kinesin-2, -4, -5, -7, -8, -9, -12, -13, and -14 families, in addition to several plant specific and ‘orphan’ kinesins are present. Most (91%) of these kinesin transcripts change in abundance throughout gametophyte development, with 52% of kinesin mRNAs enriched during the mitotic phase and 39% enriched during differentiation. Functional analyses show that the temporal regulation of kinesin transcripts during gametogenesis directly correlates with kinesin protein function. Specifically, Marsilea makes one kinesin-2 (MvKinesin-2) and two kinesin-9 (MvKinesin-9A and MvKinesin-9B) transcripts, which are present during spermatid differentiation and ciliogenesis. Silencing experiments showed that MvKinesin-2 and MvKinesin-9A are required for ciliogenesis and motility in the Marsilea male gametophyte; however, these kinesins display atypical roles during these processes. In contrast, spermatozoids produced after the silencing of MvKinesin-9B exhibit normal morphology. MvKinesin-2 is necessary for cytokinesis as well as for regulating ciliary length and MvKinesin-9A is needed for the correct orientation of basal bodies, events not typically associated with these proteins. In addition, Marsilea makes motile, ciliated gametophytes without the help of IFT dynein, outer arm dynein, or the BBsome. These results are the first to investigate the kinesin-linked mechanisms that regulate ciliogenesis in a land plant.

MECHANISM OF UPREGULATION OF PHOSPHATIDYLCHOLINE SYNTHESIS DURING PICORNAVIRUS INFECTION AND ITS ROLE IN THE DEVELOPMENT OF VIRAL REPLICATION ORGANELLES

Picornaviruses are a group of human and animal pathogens capable of inflicting serious public health diseases and economic burdens. Treatments options through vaccines for prevention or antivirals to cure infection are not available for the vast majority of these viruses. These shortcomings, in the development of vaccines or antivirals therapeutic, are linked to the genetic diversity and to an incomplete understanding of the biology of these viruses. Despite the diverse host range, this group of positive-strand RNA viruses shares the same replication mechanisms, including the development of membranous structures (replication organelles) in the cytoplasm of infected cells. The development of these membranous structures, which serve as sites for the replication of the viral RNA genome, has been linked to the hijacking of elements of the cellular membrane metabolism pathways. Here we show that upon picornavirus infection, there is a specific activation of acyl-CoA synthetase enzymes resulting in strong import and accumulation of long chain fatty acids in the cytoplasm of infected cells. We show that the newly imported fatty acids serve as a substrate for the upregulation of phosphatidylcholine synthesis required for the structural development of replication organelles. In this work, we identified that acyl-CoA synthetase long chain 3 (ACSL3) is required for the upregulation of lipids syntheses and the replication of poliovirus. We have shown that the poliovirus protein 2A was required but not sufficient for the activation of import of long chain fatty acids in infected cells. We demonstrated that the fatty acid import is upregulated upon infection by diverse picornaviruses and that such upregulation is not dependent on activation of ER stress response or the autophagy pathways. In this work, we have demonstrated that phosphatidylcholine was required for the structural development of replication organelles. Phosphatidylcholine synthesis was dispensable for the production of infectious particles at high MOI but required at a low MOI for the protection of the replication complexes from the cellular innate immunity mechanisms.