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result(s) for
"Lanham, S Andrew"
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Batman by Grant Morrison omnibus
\"One of the greatest storytellers of his generation, Grant Morrison's arrival onto the Dark Knight was one of the most hyped debuts in industry history. This collection includes time-spanning epic graphic novels featuring the cataclysmic events of FINAL CRISIS and the introduction of Batman's son, Damian Wayne! These blockbuster stories featured a deconstruction of super hero comics like never before, with challenging, thought-provoking takes on the modern, four-color icons.\"-- Provided by publisher.
Book
Generalized Noncoherent Space-Time Block Codes from Quantum Error Correction
This paper generalizes results in noncoherent space-time block code (STBC) design based on quantum error correction (QEC) to new antenna configurations. Previous work proposed QEC-inspired STBCs for antenna geometries where the number of transmit and receive antennas were equal and a power of two. In this work we extend these results by providing QEC-inspired STBCs applicable to all square antenna geometries and some rectangular geometries where the number of receive antennas is greater than the number of transmit antennas. We derive the maximum-likelihood decoding rule for this family of codes for the special case of Rayleigh fading with additive white Gaussian noise. We present Monte Carlo simulations of the performance of the codes in this environment for a three-antenna square geometry and a three-by-six rectangular geometry. We demonstrate competitive performance for these codes with respect to a popular noncoherent differential code.
Paper
Parallel Quantum Computing Emulation
Quantum computers provide a fundamentally new computing paradigm that promises to revolutionize our ability to solve broad classes of problems. Surprisingly, the basic mathematical structures of gate-based quantum computing, such as unitary operations on a finite-dimensional Hilbert space, are not unique to quantum systems but may be found in certain classical systems as well. Previously, it has been shown that one can represent an arbitrary multi-qubit quantum state in terms of classical analog signals using nested quadrature amplitude modulated signals. Furthermore, using digitally controlled analog electronics one may manipulate these signals to perform quantum gate operations and thereby execute quantum algorithms. The computational capacity of a single signal is, however, limited by the required bandwidth, which scales exponentially with the number of qubits when represented using frequency-based encoding. To overcome this limitation, we introduce a method to extend this approach to multiple parallel signals. Doing so allows a larger quantum state to be emulated with the same gate time required for processing frequency-encoded signals. In the proposed representation, each doubling of the number of signals corresponds to an additional qubit in the spatial domain. Single quit gate operations are similarly extended so as to operate on qubits represented using either frequency-based or spatial encoding schemes. Furthermore, we describe a method to perform gate operations between pairs of qubits represented using frequency or spatial encoding or between frequency-based and spatially encoded qubits. Finally, we describe how this approach may be extended to represent qubits in the time domain as well.
Paper
Quantum-Inspired Approximations to Constraint Satisfaction Problems
Two contrasting algorithmic paradigms for constraint satisfaction problems are successive local explorations of neighboring configurations versus producing new configurations using global information about the problem (e.g. approximating the marginals of the probability distribution which is uniform over satisfying configurations). This paper presents new algorithms for the latter framework, ultimately producing estimates for satisfying configurations using methods from Boolean Fourier analysis. The approach is broadly inspired by the quantum amplitude amplification algorithm in that it maximally increases the amplitude of the approximation function over satisfying configurations given sequential refinements. We demonstrate that satisfying solutions may be retrieved in a process analogous to quantum measurement made efficient by sparsity in the Fourier domain, and present a complete solver construction using this novel approximation. Freedom in the refinement strategy invites further opportunities to design solvers in an evolutionary computing framework. Results demonstrate competitive performance against local solvers for the Boolean satisfiability (SAT) problem, encouraging future work in understanding the connections between Boolean Fourier analysis and constraint satisfaction.
Paper
A Quantum-Inspired Classical Solver for Boolean k-Satisfiability Problems
In this paper we detail a classical algorithmic approach to the k-satisfiability (k-SAT) problem that is inspired by the quantum amplitude amplification algorithm. This work falls under the emerging field of quantum-inspired classical algorithms. To propose our modification, we adopt an existing problem model for k-SAT known as Universal SAT (UniSAT), which casts the Boolean satisfiability problem as a non-convex global optimization over a real-valued space. The quantum-inspired modification to UniSAT is to apply a conditioning operation to the objective function that has the effect of \"amplifying\" the function value at points corresponding to optimal solutions. We describe the algorithm for achieving this amplification, termed \"AmplifySAT,\" which follows a familiar two-step process of applying an oracle-like operation followed by a reflection about the average. We then discuss opportunities for meaningfully leveraging this processing in a classical digital or analog computing setting, attempting to identify the strengths and limitations of AmplifySAT in the context of existing non-convex optimization strategies like simulated annealing and gradient descent.
Paper
A Noncoherent Space-Time Code from Quantum Error Correction
In this work, we develop a space-time block code for noncoherent communication using techniques from the field of quantum error correction. We decompose the multiple-input multiple-output (MIMO) channel into operators from quantum mechanics, and design a non-coherent space time code using the quantum stabilizer formalism. We derive an optimal decoder, and analyze the former through a quantum mechanical lens. We compare our approach to a comparable coherent approach and a noncoherent differential approach, achieving comparable or better performance.
Paper
Identification of 5-HT2A receptor signaling pathways associated with psychedelic potential
Serotonergic psychedelics possess considerable therapeutic potential. Although 5-HT
2A
receptor activation mediates psychedelic effects, prototypical psychedelics activate both 5-HT
2A
-Gq/11 and β-arrestin2 transducers, making their respective roles unclear. To elucidate this, we develop a series of 5-HT
2A
-selective ligands with varying Gq efficacies, including β-arrestin-biased ligands. We show that 5-HT
2A
-Gq but not 5-HT
2A
-β-arrestin2 recruitment efficacy predicts psychedelic potential, assessed using head-twitch response (HTR) magnitude in male mice. We further show that disrupting Gq-PLC signaling attenuates the HTR and a threshold level of Gq activation is required to induce psychedelic-like effects, consistent with the fact that certain 5-HT
2A
partial agonists (e.g., lisuride) are non-psychedelic. Understanding the role of 5-HT
2A
Gq-efficacy in psychedelic-like psychopharmacology permits rational development of non-psychedelic 5-HT
2A
agonists. We also demonstrate that β-arrestin-biased 5-HT
2A
receptor agonists block psychedelic effects and induce receptor downregulation and tachyphylaxis. Overall, 5-HT
2A
receptor Gq-signaling can be fine-tuned to generate ligands distinct from classical psychedelics.
Serotonin 5-HT
2A
receptor signaling mechanisms associated with predicting psychedelic potential remain elusive. Using 5-HT
2A
-selective β-arrestin-biased ligands, here the authors show that a threshold level of 5-HT
2A
-Gq efficacy and not β-arrestin recruitment is associated with psychedelic potential.
Journal Article
RADICAL VISIONS FOR THE LAW OF PEACE: HOW W.E.B. DU BOIS AND THE BLACK ANTIWAR MOVEMENT REIMAGINED CIVIL RIGHTS AND THE LAWS OF WAR AND PEACE
This Article reconstructs the history of Black antiwar activism in the twentieth-century United States and argues that Black antiwar activists played a significant but largely forgotten role in the development of both modern civil rights law and the international law of war and peace. The Article focuses on the career of W.E.B. Du Bois, tracing how he built coalitions between civil rights and antiwar organizations to pursue a series of shared legal campaigns. Du Bois's antiwar work was also representative of a larger tradition, and his career illuminates how a range of Black activists and civil rights lawyers like Pauli Murray, Prentice Thomas, Ella Baker, and Martin Luther King, Jr. creatively merged civil rights and antiwar protest.
Journal Article
Heterogeneity within and among co-occurring foundation species increases biodiversity
Habitat heterogeneity is considered a primary causal driver underpinning patterns of diversity, yet the universal role of heterogeneity in structuring biodiversity is unclear due to a lack of coordinated experiments testing its effects across geographic scales and habitat types. Furthermore, key species interactions that can enhance heterogeneity, such as facilitation cascades of foundation species, have been largely overlooked in general biodiversity models. Here, we performed 22 geographically distributed experiments in different ecosystems and biogeographical regions to assess the extent to which variation in biodiversity is explained by three axes of habitat heterogeneity: the amount of habitat, its morphological complexity, and capacity to provide ecological resources (e.g. food) within and between co-occurring foundation species. We show that positive and additive effects across the three axes of heterogeneity are common, providing a compelling mechanistic insight into the universal importance of habitat heterogeneity in promoting biodiversity via cascades of facilitative interactions. Because many aspects of habitat heterogeneity can be controlled through restoration and management interventions, our findings are directly relevant to biodiversity conservation.
Species interactions that can enhance habitat heterogeneity such as facilitation cascades of foundation species have been overlooked in biodiversity models. This study conducted 22 geographically distributed experiments in different ecosystems and biogeographical regions to assess the extent to which biodiversity is explained by three axes of habitat heterogeneity in facilitation cascades.
Journal Article
Vitamins D2 and D3 Have Overlapping But Different Effects on the Human Immune System Revealed Through Analysis of the Blood Transcriptome
Vitamin D is best known for its role in maintaining bone health and calcium homeostasis. However, it also exerts a broad range of extra-skeletal effects on cellular physiology and on the immune system. Vitamins D
2
and D
3
share a high degree of structural similarity. Functional equivalence in their vitamin D-dependent effects on human physiology is usually assumed but has in fact not been well defined experimentally. In this study we seek to redress the gap in knowledge by undertaking an in-depth examination of changes in the human blood transcriptome following supplementation with physiological doses of vitamin D
2
and D
3
. Our work extends a previously published randomized placebo-controlled trial that recruited healthy white European and South Asian women who were given 15 µg of vitamin D
2
or D
3
daily over 12 weeks in wintertime in the UK (Nov-Mar) by additionally determining changes in the blood transcriptome over the intervention period using microarrays. An integrated comparison of the results defines both the effect of vitamin D
3
or D
2
on gene expression, and any influence of ethnic background. An important aspect of this analysis was the focus on the changes in expression from baseline to the 12-week endpoint of treatment
within
each individual, harnessing the longitudinal design of the study. Whilst overlap in the repertoire of differentially expressed genes was present in the D
2
or D
3
-dependent effects identified, most changes were specific to either one vitamin or the other. The data also pointed to the possibility of ethnic differences in the responses. Notably, following vitamin D
3
supplementation, the majority of changes in gene expression reflected a down-regulation in the activity of genes, many encoding pathways of the innate and adaptive immune systems, potentially shifting the immune system to a more tolerogenic status. Surprisingly, gene expression associated with type I and type II interferon activity, critical to the innate response to bacterial and viral infections, differed following supplementation with either vitamin D
2
or vitamin D
3
, with only vitamin D
3
having a stimulatory effect. This study suggests that further investigation of the respective physiological roles of vitamin D
2
and vitamin D
3
is warranted.
Journal Article