292 research outputs found
Design of Deployable Optical Space Arrays Based on a Thickened Origami Flasher Pattern
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
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
Suppose we have a network that is represented by a graph . Potentially a
fire (or other type of contagion) might erupt at some vertex of . We are
able to respond to this outbreak by establishing a firebreak at other
vertices of , so that the fire cannot pass through these fortified vertices.
The question that now arises is which 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 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
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
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 ( days) to a
luminous peak ( mag) and plateau ( mag)
extending to days with a smooth decline rate of mag
day. During the rising phase, 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
days after first light, with a transition to a higher ionization state in the
first days. Both the 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 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 in the final years before explosion, with a potentially
decreasing mass loss of in
years towards the explosion. For the eruptive mass-loss scenario, we favor
eruptions releasing 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
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 ( 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 -- days and
luminous optical peaks ( 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, 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 Ni masses
(), 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
(--) with small H-rich envelope masses
() that experience enhanced mass
loss () 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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