361 research outputs found

    Depth of Field Analysis for Multilayer Automultiscopic Displays

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    With the re-emergence of stereoscopic displays, through polarized glasses for theatrical presentations and shuttered liquid crystal eyewear in the home, automultiscopic displays have received increased attention. Commercial efforts have predominantly focused on parallax barrier and lenticular architectures applied to LCD panels. Such designs suffer from reduced resolution and brightness. Recently, multilayer LCDs have emerged as an alternative supporting full-resolution imagery with enhanced brightness and depth of field. We present a signal-processing framework for comparing the depth of field for conventional automultiscopic displays and emerging architectures comprising multiple light-attenuating layers. We derive upper bounds for the depths of field, indicating the potential of multilayer configurations to significantly enhance resolution and depth of field, relative to conventional designs.Massachusetts Institute of Technology. Media LaboratoryMIT Camera Culture GroupNational Science Foundation (U.S.) (Grant IIS-1116452)United States. Defense Advanced Research Projects Agency. MOSAIC ProgramUnited States. Defense Advanced Research Projects Agency. SCENICC ProgramAlfred P. Sloan Foundation (Research Fellowship)United States. Defense Advanced Research Projects Agency. (Young Faculty Award

    Optimizing vision and visuals: lectures on cameras, displays and perception

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    The evolution of the internet is underway, where immersive virtual 3D environments (commonly known as metaverse or telelife) will replace flat 2D interfaces. Crucial ingredients in this transformation are next-generation displays and cameras representing genuinely 3D visuals while meeting the human visual system's perceptual requirements. This course will provide a fast-paced introduction to optimization methods for next-generation interfaces geared towards immersive virtual 3D environments. Firstly, we will introduce lensless cameras for high dimensional compressive sensing (e.g., single exposure capture to a video or one-shot 3D). Our audience will learn to process images from a lensless camera at the end. Secondly, we introduce holographic displays as a potential candidate for next-generation displays. By the end of this course, you will learn to create your 3D images that can be viewed using a standard holographic display. Lastly, we will introduce perceptual guidance that could be an integral part of the optimization routines of displays and cameras. Our audience will gather experience in integrating perception to display and camera optimizations. This course targets a wide range of audiences, from domain experts to newcomers. To do so, examples from this course will be based on our in-house toolkit to be replicable for future use. The course material will provide example codes and a broad survey with crucial information on cameras, displays and perception

    Real-time Image Generation for Compressive Light Field Displays

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    With the invention of integral imaging and parallax barriers in the beginning of the 20th century, glasses-free 3D displays have become feasible. Only today—more than a century later—glasses-free 3D displays are finally emerging in the consumer market. The technologies being employed in current-generation devices, however, are fundamentally the same as what was invented 100 years ago. With rapid advances in optical fabrication, digital processing power, and computational perception, a new generation of display technology is emerging: compressive displays exploring the co-design of optical elements and computational processing while taking particular characteristics of the human visual system into account. In this paper, we discuss real-time implementation strategies for emerging compressive light field displays. We consider displays composed of multiple stacked layers of light-attenuating or polarization-rotating layers, such as LCDs. The involved image generation requires iterative tomographic image synthesis. We demonstrate that, for the case of light field display, computed tomographic light field synthesis maps well to operations included in the standard graphics pipeline, facilitating efficient GPU-based implementations with real-time framerates.United States. Defense Advanced Research Projects Agency. Soldier Centric Imaging via Computational CamerasNational Science Foundation (U.S.) (Grant IIS-1116452)United States. Defense Advanced Research Projects Agency. Maximally scalable Optical Sensor Array Imaging with Computation ProgramAlfred P. Sloan Foundation (Research Fellowship)United States. Defense Advanced Research Projects Agency (Young Faculty Award

    Construction and Calibration of Optically Efficient LCD-based Multi-Layer Light Field Displays

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    Near-term commercial multi-view displays currently employ ray-based 3D or 4D light field techniques. Conventional approaches to ray-based display typically include lens arrays or heuristic barrier patterns combined with integral interlaced views on a display screen such as an LCD panel. Recent work has placed an emphasis on the co-design of optics and image formation algorithms to achieve increased frame rates, brighter images, and wider fields-of-view using optimization-in-the-loop and novel arrangements of commodity LCD panels. In this paper we examine the construction and calibration methods of computational, multi-layer LCD light field displays. We present several experimental configurations that are simple to build and can be tuned to sufficient precision to achieve a research quality light field display. We also present an analysis of moiré interference in these displays, and guidelines for diffuser placement and display alignment to reduce the effects of moiré. We describe a technique using the moiré magnifier to fine-tune the alignment of the LCD layers

    Cholesterol Sulfotransferase SULT2B1b Modulates Sensitivity to Death Receptor Ligand TNFα in Castration-Resistant Prostate Cancer

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    Cholesterol sulfotransferase, SULT2B1b, has been demonstrated to modulate both androgen receptor activity and cell growth properties. However, the mechanism(s) by which SULT2B1b alters these properties within prostate cancer cells has not been described. Furthermore, specific advantages of SULT2B1b expression in prostate cancer cells is not understood. In these studies, single-cell mRNA sequencing (scRNA-seq) was conducted to compare the transcriptomes of SULT2B1b knockdown (KD) versus Control KD LNCaP cells. Over 2,000 differentially expressed (DE) genes were identified along with alterations in numerous canonical pathways, including the death receptor signaling pathway. The studies herein demonstrate that SULT2B1b KD increases tumor necrosis factor alpha (TNF) expression in prostate cancer cells and results in NF-κB activation in a TNF-dependent manner. More importantly, SULT2B1b KD significantly enhances TNF-mediated apoptosis in both TNF-sensitive LNCaP cells and TNF-resistant C4–2 cells. Overexpression of SULT2B1b in LNCaP cells also decreases sensitivity to TNF-mediated cell death, suggesting that SULT2B1b modulates pathways dictating the TNF sensitivity capacity of prostate cancer cells. Probing human prostate cancer patient datasets further support this work by providing evidence that SULT2B1b expression is inversely correlated with TNF-related genes, including TNF, CD40LG, FADD, and NFKB1. Together, these data provide evidence that SULT2B1b expression in prostate cancer cells enhances resistance to TNF and may provide a growth advantage. In addition, targeting SULT2B1b may induce an enhanced therapeutic response to TNF treatment in advanced prostate cancer

    The Artificial Society Analytics Platform

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    Author's accepted manuscriptSocial simulation routinely involves the construction of artificial societies and agents within such societies. Currently there is insufficient discussion of best practices regarding the construction process. This chapter introduces the artificial society analytics platform (ASAP) as a way to spark discussion of best practices. ASAP is designed to be an extensible architecture capable of functioning as the core of many different types of inquiries into social dynamics. Here we describe ASAP, focusing on design decisions in several key areas, thereby exposing our assumptions and reasoning to critical scrutiny, hoping for discussion that can advance debate over best practices in artificial society construction. The five design decisions are related to agent characteristics, neighborhood interactions, evaluating agent credibility, agent marriage, and heritability of personality.acceptedVersio

    Extreme genetic fragility of the HIV-1 capsid

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    Genetic robustness, or fragility, is defined as the ability, or lack thereof, of a biological entity to maintain function in the face of mutations. Viruses that replicate via RNA intermediates exhibit high mutation rates, and robustness should be particularly advantageous to them. The capsid (CA) domain of the HIV-1 Gag protein is under strong pressure to conserve functional roles in viral assembly, maturation, uncoating, and nuclear import. However, CA is also under strong immunological pressure to diversify. Therefore, it would be particularly advantageous for CA to evolve genetic robustness. To measure the genetic robustness of HIV-1 CA, we generated a library of single amino acid substitution mutants, encompassing almost half the residues in CA. Strikingly, we found HIV-1 CA to be the most genetically fragile protein that has been analyzed using such an approach, with 70% of mutations yielding replication-defective viruses. Although CA participates in several steps in HIV-1 replication, analysis of conditionally (temperature sensitive) and constitutively non-viable mutants revealed that the biological basis for its genetic fragility was primarily the need to coordinate the accurate and efficient assembly of mature virions. All mutations that exist in naturally occurring HIV-1 subtype B populations at a frequency >3%, and were also present in the mutant library, had fitness levels that were >40% of WT. However, a substantial fraction of mutations with high fitness did not occur in natural populations, suggesting another form of selection pressure limiting variation in vivo. Additionally, known protective CTL epitopes occurred preferentially in domains of the HIV-1 CA that were even more genetically fragile than HIV-1 CA as a whole. The extreme genetic fragility of HIV-1 CA may be one reason why cell-mediated immune responses to Gag correlate with better prognosis in HIV-1 infection, and suggests that CA is a good target for therapy and vaccination strategies

    Genomic profile of advanced breast cancer in circulating tumour DNA.

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    The genomics of advanced breast cancer (ABC) has been described through tumour tissue biopsy sequencing, although these approaches are limited by geographical and temporal heterogeneity. Here we use plasma circulating tumour DNA sequencing to interrogate the genomic profile of ABC in 800 patients in the plasmaMATCH trial. We demonstrate diverse subclonal resistance mutations, including enrichment of HER2 mutations in HER2 positive disease, co-occurring ESR1 and MAP kinase pathway mutations in HR + HER2- disease that associate with poor overall survival (p = 0.0092), and multiple PIK3CA mutations in HR + disease that associate with short progression free survival on fulvestrant (p = 0.0036). The fraction of cancer with a mutation, the clonal dominance of a mutation, varied between genes, and within hotspot mutations of ESR1 and PIK3CA. In ER-positive breast cancer subclonal mutations were enriched in an APOBEC mutational signature, with second hit PIK3CA mutations acquired subclonally and at sites characteristic of APOBEC mutagenesis. This study utilises circulating tumour DNA analysis in a large clinical trial to demonstrate the subclonal diversification of pre-treated advanced breast cancer, identifying distinct mutational processes in advanced ER-positive breast cancer, and novel therapeutic opportunities
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