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New One Shot Quantum Protocols With Application to Communication Complexity
No full textIn this paper we present the following quantum compression protocol:
P : Let ρ,σ be quantum states such that S(ρ||σ)=Tr(ρlogρ−ρlogσ), the relative entropy between ρ and σ, is finite. Alice gets to know the eigen-decomposition of ρ. Bob gets to know the eigen-decomposition of σ. Both Alice and Bob know S(ρ||σ) and an error parameter ϵ. Alice and Bob use shared entanglement and after communication of ((S(ρ||σ)+1)/ϵ4) bits from Alice to Bob, Bob ends up with a quantum state ρ̃ such that F(ρ,ρ̃ )≥1−5ϵ, where F(⋅) represents fidelity.
This result can be considered as a non-commutative generalization of a result due to Braverman and Rao [2011] where they considered the special case when ρ and σ are classical probability distributions (or commute with each other) and use shared randomness instead of shared entanglement. We use P to obtain an alternate proof of a direct-sum result for entanglement assisted quantum one-way communication complexity for all relations, which was first shown by Jain, Radhakrishnan and Sen [2005,2008]. We also present a variant of protocol P in which Bob has some side information about the state with Alice. We show that in such a case, the amount of communication can be further reduced, based on the side information that Bob has.
Our second result provides a quantum analogue of the widely used classical correlated-sampling protocol. For example, Holenstein [2007] used the classical correlated-sampling protocol in his proof of a parallel-repetition theorem for two-player one-round games.Accepted Manuscrip
Dynamic expression of pleiotropic developmental genes during Drosophila embryogenesis
No full textDuring embryonic development transcription must be precisely regulated over space and time to differentiate tissues and form organs. Organogenesis is directed by a set of pleiotropic transcription factors that are conserved across species and are expressed in diverse tissues during embryogenesis. These transcription factors drive spatiotemporal patterns of gene expression by binding to regulatory DNA called enhancers. Distinct enhancers are thought to drive expression in each tissue. The field has made enormous progress on understanding how enhancers limit expression to a specific tissue, but much less is understood about how enhancers control the dynamics of gene expression. These dynamics can vary widely between developing tissues as genes may be expressed for minutes to days and precise timescales are critical for both cell differentiation and tissue function. In this work, we investigate how the developmental gene even-skipped (eve) is quantitatively expressed during multiple stages of embryogenesis in Drosophila melanogaster, using in vivo microscopy of nascent transcription from the endogenous eve locus. This method allows us to compare the detailed dynamics of eve expression in diverse tissues. We demonstrate that the dynamics of eve transcription are quantitatively similar between tissues, despite expression being controlled by different enhancers and expression continuing over different timescales. Further, we examine the transcription factor binding site composition of eve’s tissue-specific enhancers to probe how these enhancers may contribute to tissue specification in diverse contexts. Our results provide quantitative insights into gene regulation in multiple tissues in the endogenous context during development, a context that has traditionally been difficult to probe. Our results suggest that different timescales of gene expression can be achieved using the same underlying dynamics of transcription and therefore challenges existing conceptions of enhancer-driven transcriptional regulation. This underscores the need to further probe how different timescales of expression are achieved through additional mechanisms of gene regulation. Together, this work provides new insight into how conserved and critical developmental genes can be re-used during embryogenesis.Medical SciencesMedical Science
The George Parker Winship Lecture Series at Houghton Library: Appendix to "A Bibliographer's Creed"
No full textVersion of Recor
An Anion-Binding Approach to Enantioselective Catalytic Reactions of Cationic Transition-Metal and Cation Radical Intermediates
No full textIn Chapter 1, we describe a new approach to inducing enantioselectivity in transition-metal-catalyzed reactions. This strategy relies on the association of chiral hydrogen-bond donors with anions of achiral metal complexes to achieve enantiocontrol and rate enhancement through ion-pairing and other noncovalent interactions. A chiral bis-thiourea hydrogen-bond donor is identified to impart enantioselectivity to ruthenium-catalyzed intramolecular propargylic substitution reactions, yielding chromane derivatives in up to 99% enantiomeric excess. Mechanistic investigations of the developed catalytic system show that the association between the bis-thiourea hydrogen-bond donor and diruthenium complexes relies on anion binding and does not involve any dative bonding interactions with the metal center. Spectroscopic, kinetic, and computational studies reveal attractive interactions between the electron-deficient arene components of the hydrogen-bond donor and the ligands of the metal complex, which contribute to enantioinduction and the observed acceleration effect.
In Chapter 2, we describe the application of anion-binding catalysis with chiral hydrogen-bond donors as a new strategy to achieve enantiocontrol in photoredox reactions proceeding through cation radical intermediates. Cooperative catalysis between aryl-pyrrolidine tert-leucine hydrogen-bond donors and pyrylium salts enables cycloaddition reactions of electron-rich alkene substrates to provide enantioenriched 3–6-membered carbocyclic products. The synthetic utility of the developed (2+2) cycloaddition reaction is demonstrated through its application to the synthesis of the enantiomer of a glucocorticoid receptor binder, (+)-endiandrin A, in 99% enantiomeric excess
AN EXPLORATORY QUALITATIVE STUDY ON THE LEARNING EXPERIENCES OF CANADIAN CERTIFIED PHYSICIAN ASSISTANTS WORKING IN CRITICAL CARE SETTINGS
No full textBackground: Physician Assistants are healthcare professionals trained to diagnose, treat, and manage patients under physicians’ supervision, being essential members of diverse medical teams. Given they receive training as generalists, upon securing employment, their educational trajectory is adapted to their selected field, facilitating the acquisition of specialized expertise and skills. In Canadian contexts, graduate schools often provide relatively brief training in critical care, with Intensive Care Units experiences typically offered as an elective rotation. The example of adjusting to a critical care setting could increase our understanding of the full educational journey of PAs, including their strengths and challenges following graduation.
Methods and Analysis: In this qualitative exploratory study, ten participants employed in critical care settings across five diverse Canadian centers engaged in semi-structured individual interviews conducted via Zoom video calls. These interviews, guided by a predefined interview guide, centered on their learning experiences within the workplace. Following the transcription of interviews, analysis was conducted utilizing inductive thematic analysis with constant comparison.
Results: Four overarching themes were identified: 1) Facilitators of Learning, highlighting factors that support PAs in their learning process during on-the-job training, 2) Barriers to Learning, which identified specific factors hindering PAs' full engagement in the learning process, acting as obstacles to absorbing new knowledge effectively, 3) Attitudes Towards Professional Development, exploring the strategies PAs employ for their professional growth, aiming to minimize unproductive downtime and maximize engaging learning opportunities, and 4) Maximizing learning Experiences In Critical Care Units, delving into PAs' suggestions for changes in their current environment to enhance learning during on-the-job training.
Conclusions: This study highlights the crucial role of preceptors in safely guiding PAs' transition to full professionals in critical care settings. It provides insights that could guide initiatives to enhance the preparedness and effectiveness of PAs in navigating the complexities of critical care practice. Additionally, it suggests potential avenues for creating a specialized curriculum tailored to address the specific needs of PAs in this particular field
Searching for our Soul: An American Road Odyssey
No full textAbstract
Searching for Our Soul: An American Road Odyssey is part three of a memoir written over eighteen months. The narratives take place during the COVID-19 pandemic from September of 2020 to April of 2022. The third section begins at my home in Connecticut and travels out into western deserts, going as far as the Grand Canyon, before returning home. The original goal was to cross our country and take the temperature of everyday Americans by speaking with people about what was on their minds, and what worried them regarding the divisiveness, politics, and the virus that placed a stranglehold on our country. Over the eighteen months, the story’s focus evolved and, true to the “Road” genre tradition, became an exercise in self-reflection and transformation
Soil carbon in tropical savannas mostly derived from grasses
No full textTropical savannas have been increasingly targeted for carbon (C) sequestration from afforestation, assuming large gains in soil organic C (SOC) with increasing tree cover. This assumption may not reflect real changes in SOC under afforestation, because savanna SOC is also derived from grasses, but grass contributions to SOC and SOC changes with increasing tree cover remain poorly synthesized. Here, we combine a case study from Kruger, in South Africa, with data synthesized across tropical savannas from 148 soil profiles to 1-meter depth to show that grass-derived C constitutes more than half of total SOC, even in soils directly under trees. The largest SOC concentrations were associated with the largest grass contributions (> 70% of total SOC). Regionally or across the tropics, SOC concentration was not explained by tree cover. Both SOC gain and loss were observed following increasing tree cover, and on average SOC storage only increased by a negligible 6%. These results underscore the substantial contribution of grasses to SOC and the considerable uncertainty inherent in SOC responses to increasing tree cover, challenging the widespread assumption that afforestation universally and substantially enhances SOC storage across tropical savannas.Accepted Manuscrip
Jiangxi Literati and Interregional Networks in Thirteenth- to Fifteenth-Century China
No full textFrom the thirteenth to fifteenth centuries, literary interactions were essential to the formation and functioning of literati society beyond local society in China. By tracing the circulation of occasional writings, this study demonstrates how literary interactions provided a way for literati to connect with their peers from other localities and establish interregional networks. Literati developed such social spaces in between by traveling and socializing for reasons beyond the civil service examination, government duties, and Neo-Confucian teachings. These spaces also allowed for the wide circulation of information and facilitated the exchange of opinions on issues of shared interest or concern. The relationship between the networks based on literary interactions and other interregional networks underwent significant changes during the Southern Song (1127–1279), Mongol-Yuan (1271–1368), and Ming (1368–1644) dynasties. This study presents case studies of literati from central Jiangxi to illustrate the transformations in their views and experiences. In the first chapter, I outline different types of interregional networks in the Southern Song, paying particular attention to literary social circles created by literati outside the bureaucracy. The second chapter focuses on the first half of the fourteenth century, when the Mongol court began to incorporate more southern literati into the bureaucracy. The third chapter turns to the late Yuan and early Ming—from the late fourteenth century to the early fifteenth century. This chapter explores a period in which Ming emperors sought to create a single literary social circle. The fourth chapter examines the development of literary social circles up to 1449. In this new era, literary social circles, which had previously provided social spaces between the bureaucracy and local society, no longer seemed to be active
How local is the information in tensor networks of matrix product states or projected entangled pairs states
No full textTwo dimensional tensor networks such as projected entangled pairs states (PEPS) are generally hard to contract. This is arguably the main reason why variational tensor network methods in 2D are still not as successful as in 1D. However, this is not necessarily the case if the tensor network represents a gapped ground state of a local Hamiltonian; such states are subject to many constraints and contain much more structure. In this paper we introduce a new approach for approximating the expectation value of a local observable in ground states of local Hamiltonians that are represented as PEPS tensor-networks. Instead of contracting the full tensor-network, we try to estimate the expectation value using only a local patch of the tensor-network around the observable. Surprisingly, we demonstrate that this is often easier to do when the system is frustrated. In such case, the spanning vectors of the local patch are subject to non-trivial constraints that can be utilized via a semi-definite program to calculate rigorous lower- and upper-bounds on the expectation value. We test our approach in 1D systems, where we show how the expectation value can be calculated up to at least 3 or 4 digits of precision, even when the patch radius is smaller than the correlation length.Accepted Manuscrip
