292 research outputs found

    Design of the Termite - 100 A Cellulose Shredding Machine

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    Design of Deployable Optical Space Arrays Based on a Thickened Origami Flasher Pattern

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    Performance of space-based optics could be greatly enhanced by using deployable origami-based arrays, which can offer a large aperture size relative to their stowed volume when compared to traditional technology, thus improving imaging quality. In this work, we select, develop, and adapt the origami flasher pattern to serve as the foundation for a deployable array that shows promise for meeting stringent optical requirements. We apply a novel thickness accommodation technique, improve stability by adjusting geometric characteristics of the pattern, and create an array of frames for housing optical elements in a co-planar configuration. By following the guidelines in this work, more efficient and powerful optical arrays can be developed

    Algorithm-Based Meta-Analysis Reveals the Mechanistic Interaction of the Tumor Suppressor LIMD1 With Non-Small-Cell Lung Carcinoma

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    Non-small-cell lung carcinoma (NSCLC) is the major type of lung cancer, which is among the leading causes of cancer-related deaths worldwide. LIMD1 was previously identified as a tumor suppressor in lung cancer, but their detailed interaction in this setting remains unclear. In this study, we have carried out multiple genome-wide bioinformatic analyses for a comprehensive understanding of LIMD1 in NSCLC, using various online algorithm platforms that have been built for mega databases derived from both clinical and cell line samples. Our results indicate that LIMD1 expression level is significantly downregulated at both mRNA and protein levels in both lung adenocarcinoma (LUAD) and lung squamous cell carcinoma (LUSC), with a considerable contribution from its promoter methylation rather than its gene mutations. The Limd1 gene undergoes mutation only at a low rate in NSCLC (0.712%). We have further identified LIMD1-associated molecular signatures in NSCLC, including its natural antisense long non-coding RNA LIMD1-AS1 and a pool of membrane trafficking regulators. We have also identified a subgroup of tumor-infiltrating lymphocytes, especially neutrophils, whose tumor infiltration levels significantly correlate with LIMD1 level in both LUAD and LUSC. However, a significant correlation of LIMD1 with a subset of immune regulatory molecules, such as IL6R and TAP1, was only found in LUAD. Regarding the clinical outcomes, LIMD1 expression level only significantly correlates with the survival of LUAD (p0.1) patients. These findings indicate that LIMD1 plays a survival role in LUAD patients at least by acting as an immune regulatory protein. To further understand the mechanisms underlying the tumor-suppressing function of LIMD1 in NSCLC, we show that LIMD1 downregulation remarkably correlates with the deregulation of multiple pathways that play decisive roles in the oncogenesis of NSCLC, especially those mediated by EGFR, KRAS, PIK3CA, Keap1, and p63, in both LUAD and LUSC, and those mediated by p53 and CDKN2A only in LUAD. This study has disclosed that LIMD1 can serve as a survival prognostic marker for LUAD patients and provides mechanistic insights into the interaction of LIMD1 with NSCLC, which provide valuable information for clinical applications

    The Firebreak Problem

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    Suppose we have a network that is represented by a graph GG. Potentially a fire (or other type of contagion) might erupt at some vertex of GG. We are able to respond to this outbreak by establishing a firebreak at kk other vertices of GG, so that the fire cannot pass through these fortified vertices. The question that now arises is which kk vertices will result in the greatest number of vertices being saved from the fire, assuming that the fire will spread to every vertex that is not fully behind the kk vertices of the firebreak. This is the essence of the {\sc Firebreak} decision problem, which is the focus of this paper. We establish that the problem is intractable on the class of split graphs as well as on the class of bipartite graphs, but can be solved in linear time when restricted to graphs having constant-bounded treewidth, or in polynomial time when restricted to intersection graphs. We also consider some closely related problems

    Depiction of Lying Down and Standing up Sequences in Multiparous Sows

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    The objective of this study was tocreatea pictorial lying down-standing up sequence depiction in multiparous sows.Eighty-five multiparous sows were moved from their home stallto a testingstall where they were video recorded for one lying down–standing up event on 30, 60 and 90 days of gestation. The digital video camera was positioned on the adjacent stall so the sows’ profile was visible while recording. Observations ceased when the sow successfully lied down or if 2.5 hours elapsed since recording began. Normal standing and lying pictorial depictions were created, and deviations fromthenormal lying down and standing up sequences were also pictorially depicted. This is the first published pictorial depictions on mulitparous sows on the standing-lying-standing sequence

    From Discovery to the First Month of the Type II Supernova 2023ixf: High and Variable Mass Loss in the Final Year Before Explosion

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    We present the discovery of Type II supernova (SN) 2023ixf in M101, among the closest core-collapse SNe in the last several decades, and follow-up photometric and spectroscopic observations in the first month of its evolution. The light curve is characterized by a rapid rise (≈5\approx5 days) to a luminous peak (MV≈−18M_V\approx-18 mag) and plateau (MV≈−17.6M_V\approx-17.6 mag) extending to 3030 days with a smooth decline rate of ≈0.03\approx0.03 mag day−1^{-1}. During the rising phase, U−VU-V color shows blueward evolution, followed by redward evolution in the plateau phase. Prominent flash features of hydrogen, helium, carbon, and nitrogen dominate the spectra up to ≈5\approx5 days after first light, with a transition to a higher ionization state in the first ≈2\approx2 days. Both the U−VU-V color and flash ionization states suggest a rise in the temperature, indicative of a delayed shock-breakout inside dense circumstellar material (CSM). From the timescales of CSM interaction, we estimate its compact radial extent of ∼(3−7)×1014\sim(3-7)\times10^{14} cm. We then construct numerical light-curve models based on both continuous and eruptive mass-loss scenarios shortly before explosion. For the continuous mass-loss scenario, we infer a range of mass-loss history with 0.1−1.00.1-1.0 M⊙yr−1M_\odot {\rm yr}^{-1} in the final 2−12-1 years before explosion, with a potentially decreasing mass loss of 0.01−0.10.01-0.1 M⊙yr−1M_\odot {\rm yr}^{-1} in ∼0.7−0.4\sim0.7-0.4 years towards the explosion. For the eruptive mass-loss scenario, we favor eruptions releasing 0.3−10.3-1 M⊙M_\odot of the envelope at about a year before explosion, which result in CSM with mass and extent similar to the continuous scenario. We discuss the implications of the available multi-wavelength constraints obtained thus far on the progenitor candidate and SN 2023ixf to our variable CSM models.Comment: 15 pages, 5 figures, submitted to ApJ

    Luminous Type II Short-Plateau Supernovae 2006Y, 2006ai, and 2016egz: A Transitional Class from Stripped Massive Red Supergiants

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    The diversity of Type II supernovae (SNe II) is thought to be driven mainly by differences in their progenitor's hydrogen-rich (H-rich) envelope mass, with SNe IIP having long plateaus (∼100\sim100 days) and the most massive H-rich envelopes. However, it is an ongoing mystery why SNe II with short plateaus (tens of days) are rarely seen. Here we present optical/near-infrared photometric and spectroscopic observations of luminous Type II short-plateau SNe 2006Y, 2006ai, and 2016egz. Their plateaus of about 5050--7070 days and luminous optical peaks (≲−18.4\lesssim-18.4 mag) indicate significant pre-explosion mass loss resulting in partially-stripped H-rich envelopes and early circumstellar material (CSM) interaction. We compute a large grid of MESA+STELLA single-star progenitor and light-curve models with various progenitor zero-age main-sequence (ZAMS) masses, mass-loss efficiencies, explosion energies, 56^{56}Ni masses, and CSM densities. Our model grid shows a continuous population of SNe IIP--IIL--IIb-like light-curve morphology in descending order of H-rich envelope mass. With large 56^{56}Ni masses (≳0.05 M⊙\gtrsim0.05\,M_\odot), short-plateau SNe II lie in a confined parameter space as a transitional class between SNe IIL and IIb. For SNe 2006Y, 2006ai, and 2016egz, our findings suggest high-mass red supergiant (RSG) progenitors (MZAMS≃18M_{\rm ZAMS} \simeq 18--22 M⊙22\,M_{\odot}) with small H-rich envelope masses (MHenv≃1.7 M⊙M_{\rm H_{\rm env}} \simeq 1.7\,M_{\odot}) that experience enhanced mass loss (M˙≃10−2 M⊙ yr−1\dot{M} \simeq 10^{-2}\,M_{\odot}\,{\rm yr}^{-1}) for the last few decades before the explosion. If high-mass RSGs result in rare short-plateau SNe II, then these events might ease some of the apparent under-representation of higher-luminosity RSGs in observed SN II progenitor samples.Comment: 26 pages, 16 figures, submitted to Ap
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