198 research outputs found

    Blending Generative Adversarial Image Synthesis with Rendering for Computer Graphics

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    Conventional computer graphics pipelines require detailed 3D models, meshes, textures, and rendering engines to generate 2D images from 3D scenes. These processes are labor-intensive. We introduce Hybrid Neural Computer Graphics (HNCG) as an alternative. The contribution is a novel image formation strategy to reduce the 3D model and texture complexity of computer graphics pipelines. Our main idea is straightforward: Given a 3D scene, render only important objects of interest and use generative adversarial processes for synthesizing the rest of the image. To this end, we propose a novel image formation strategy to form 2D semantic images from 3D scenery consisting of simple object models without textures. These semantic images are then converted into photo-realistic RGB images with a state-of-the-art conditional Generative Adversarial Network (cGAN) based image synthesizer trained on real-world data. Meanwhile, objects of interest are rendered using a physics-based graphics engine. This is necessary as we want to have full control over the appearance of objects of interest. Finally, the partially-rendered and cGAN synthesized images are blended with a blending GAN. We show that the proposed framework outperforms conventional rendering with ablation and comparison studies. Semantic retention and Fr\'echet Inception Distance (FID) measurements were used as the main performance metrics

    Hardness and approximation for the geodetic set problem in some graph classes

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    In this paper, we study the computational complexity of finding the \emph{geodetic number} of graphs. A set of vertices SS of a graph GG is a \emph{geodetic set} if any vertex of GG lies in some shortest path between some pair of vertices from SS. The \textsc{Minimum Geodetic Set (MGS)} problem is to find a geodetic set with minimum cardinality. In this paper, we prove that solving the \textsc{MGS} problem is NP-hard on planar graphs with a maximum degree six and line graphs. We also show that unless P=NPP=NP, there is no polynomial time algorithm to solve the \textsc{MGS} problem with sublogarithmic approximation factor (in terms of the number of vertices) even on graphs with diameter 22. On the positive side, we give an O(n3logn)O\left(\sqrt[3]{n}\log n\right)-approximation algorithm for the \textsc{MGS} problem on general graphs of order nn. We also give a 33-approximation algorithm for the \textsc{MGS} problem on the family of solid grid graphs which is a subclass of planar graphs

    Diel metabolomics analysis of a hot spring chlorophototrophic microbial mat leads to new hypotheses of community member metabolisms

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    © 2015 Kim, Nowack, Olsen, Becraft, Wood, Thiel, Klapper, Kühl, Fredrickson, Bryant, Ward and Metz. Dynamic environmental factors such as light, nutrients, salt, and temperature continuously affect chlorophototrophic microbial mats, requiring adaptive and acclimative responses to stabilize composition and function. Quantitative metabolomics analysis can provide insights into metabolite dynamics for understanding community response to such changing environmental conditions. In this study, we quantified volatile organic acids, polar metabolites (amino acids, glycolytic and citric acid cycle intermediates, nucleobases, nucleosides, and sugars), wax esters, and polyhydroxyalkanoates, resulting in the identification of 104 metabolites and related molecules in thermal chlorophototrophic microbial mat cores collected over a diel cycle in Mushroom Spring, Yellowstone National Park. A limited number of predominant taxa inhabit this community and their functional potentials have been previously identified through metagenomic and metatranscriptomic analyses and in situ metabolisms, and metabolic interactions among these taxa have been hypothesized. Our metabolomics results confirmed the diel cycling of photorespiration (e.g. glycolate) and fermentation (e.g. acetate, propionate, and lactate) products, the carbon storage polymers polyhydroxyalkanoates, and dissolved gases (e.g. H2 and CO2) in the waters overlying the mat, which were hypothesized to occur in major mat chlorophototrophic community members. In addition, we have formulated the following new hypotheses: 1) the morning hours are a time of biosynthesis of amino acids, DNA, and RNA; 2) photo-inhibited cells may also produce lactate via fermentation as an alternate metabolism; 3) glycolate and lactate are exchanged among Synechococcus and Roseiflexus spp.; and 4) fluctuations in many metabolite pools (e.g. wax esters) at different times of day result from species found at different depths within the mat responding to temporal differences in their niches

    The IKKâ related kinase TBK1 activates mTORC1 directly in response to growth factors and innate immune agonists

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    The innate immune kinase TBK1 initiates inflammatory responses to combat infectious pathogens by driving production of type I interferons. TBK1 also controls metabolic processes and promotes oncogeneâ induced cell proliferation and survival. Here, we demonstrate that TBK1 activates mTOR complex 1 (mTORC1) directly. In cultured cells, TBK1 associates with and activates mTORC1 through siteâ specific mTOR phosphorylation (on S2159) in response to certain growth factor receptors (i.e., EGFâ receptor but not insulin receptor) and pathogen recognition receptors (PRRs) (i.e., TLR3; TLR4), revealing a stimulusâ selective role for TBK1 in mTORC1 regulation. By studying cultured macrophages and those isolated from genome edited mTOR S2159A knockâ in mice, we show that mTOR S2159 phosphorylation promotes mTORC1 signaling, IRF3 nuclear translocation, and IFNâ β production. These data demonstrate a direct mechanistic link between TBK1 and mTORC1 function as well as physiologic significance of the TBK1â mTORC1 axis in control of innate immune function. These data unveil TBK1 as a direct mTORC1 activator and suggest unanticipated roles for mTORC1 downstream of TBK1 in control of innate immunity, tumorigenesis, and disorders linked to chronic inflammation.SynopsisTBK1, an IKKâ related kinase that drives interferon production as well cancer cell proliferation and survival, phosphorylates mTOR to activate mTORC1 in response to EGF and innate immune agonists, suggesting unanticipated roles for mTORC1 downstream of TBK1 in control of innate immunity and tumorigenesis.TBK1 interacts with mTORC1 and phosphorylates mTOR on S2159 to increase its catalytic activity.Cells lacking TBK1 or expressing a mTOR S2159A allele exhibit reduced mTORC1 signaling in response to EGFâ receptor and TLR3/4 activation.Primary macrophages derived from genome edited mTOR S2159A mice exhibit reduced mTORC1 signaling in response to TLR3/4 activation.Primary macrophages treated with rapamycin as well as those derived from mTORS2159A mice produce reduced levels of IFNâ β due to impaired nuclear translocation of the transcription factor IRF3.Innate immune kinase TBK1â dependent activation of mTORC1 occurs in response to pathogen recognition and EGF receptor activation and drives interferon production, thus highlighting the role of mTOR for innate immunity.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/141029/1/embj201696164.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/141029/2/embj201696164.reviewer_comments.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/141029/3/embj201696164_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/141029/4/embj201696164-sup-0001-EVFigs.pd

    Management of children with congenital nephrotic syndrome: challenging treatment paradigms

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    Background: Management of children with congenital nephrotic syndrome (CNS) is challenging. Bilateral nephrectomies followed by dialysis and transplantation are practiced in most centres, but conservative treatment may also be effective. / Methods: We conducted a 6-year review across members of the European Society for Paediatric Nephrology Dialysis Working Group to compare management strategies and their outcomes in children with CNS. / Results: Eighty children (50% male) across 17 tertiary nephrology units in Europe were included (mutations in NPHS1, n = 55; NPHS2, n = 1; WT1, n = 9; others, n = 15). Excluding patients with mutations in WT1, antiproteinuric treatment was given in 42 (59%) with an increase in S-albumin in 70% by median 6 (interquartile range: 3–8) g/L (P < 0.001). Following unilateral nephrectomy, S-albumin increased by 4 (1–8) g/L (P = 0.03) with a reduction in albumin infusion dose by 5 (2–9) g/kg/week (P = 0.02). Median age at bilateral nephrectomies (n = 29) was 9 (7–16) months. Outcomes were compared between two groups of NPHS1 patients: those who underwent bilateral nephrectomies (n = 25) versus those on conservative management (n = 17). The number of septic or thrombotic episodes and growth were comparable between the groups. The response to antiproteinuric treatment, as well as renal and patient survival, was independent of NPHS1 mutation type. At final follow-up (median age 34 months) 20 (80%) children in the nephrectomy group were transplanted and 1 died. In the conservative group, 9 (53%) remained without dialysis, 4 (24%; P < 0.001) were transplanted and 2 died. / Conclusion: An individualized, stepwise approach with prolonged conservative management may be a reasonable alternative to early bilateral nephrectomies and dialysis in children with CNS and NPHS1 mutations. Further prospective studies are needed to define indications for unilateral nephrectomy
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