Institution
University of Colorado Boulder
Education•Boulder, Colorado, United States•
About: University of Colorado Boulder is a education organization based out in Boulder, Colorado, United States. It is known for research contribution in the topics: Population & Galaxy. The organization has 48794 authors who have published 115151 publications receiving 5387328 citations. The organization is also known as: CU Boulder & UCB.
Topics: Population, Galaxy, Poison control, Solar wind, Stars
Papers published on a yearly basis
Papers
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TL;DR: The structures of the pectic polymers (the neutral arabinan, the neutral galactan, and the acidic rhamnogalacturonan) were obtained by methylation analysis of fragments of these polymers which were released from the sycamore walls by the action of a highly purified endopolygalacturonase.
Abstract: Cell wall strength is decreased by both auxin treatment and low pH. In a recently proposed model of the plant cell wall, xyloglucan polymers are hydrogen-bonded to cellulose fibrils, forming the only noncovalent link in the network of polymers which cross-link the cellulose fibers. The decreased strength of the cell wall seen upon lowering the pH might be due to an effect of hydrogen ions on the rate of xyloglucan creep along cellulose fibers. This paper investigates binding of xyloglucan fragments to cellulose. At equilibrium, the per cent of nine- and seven-sugar xyloglucan fragments which are bound to cellulose is sensitive to both temperature and the concentration of nonaqueous solvents. However, neither the per cent of xyloglucan fragments bound to cellulose at equilibrium, nor the rate at which the xyloglucan fragments bind to cellulose, is sensitive to changes in hydrogen ion concentration. These results support the hypothesis that, within the cell wall, xyloglucan chains are connected to cellulose fibers by hydrogen bonds, but these results suggest that this interconnection between xyloglucan and cellulose is unlikely to be the point within the wall which regulates the rate of cell elongation.
632 citations
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TL;DR: A simple point-of-care test that is inexpensive enough to use frequently, even if it lacks sensitivity, is proposed for Covid-19 cases.
Abstract: Rethinking Covid-19 Test Sensitivity As Covid-19 cases accelerate or plateau around the world, we urgently need a point-of-care test that is inexpensive enough to use frequently, even if it lacks h...
632 citations
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TL;DR: The algorithm described here, called OptQuest/NLP or OQNLP, is a heuristic designed to find global optima for pure and mixed integer nonlinear problems with many constraints and variables, where all problem functions are differentiable with respect to the continuous variables.
Abstract: The algorithm described here, called OptQuest/NLP or OQNLP, is a heuristic designed to find global optima for pure and mixed integer nonlinear problems with many constraints and variables, where all problem functions are differentiable with respect to the continuous variables. It uses OptQuest, a commercial implementation of scatter search developed by OptTek Systems, Inc., to provide starting points for any gradient-based local solver for nonlinear programming (NLP) problems. This solver seeks a local solution from a subset of these points, holding discrete variables fixed. The procedure is motivated by our desire to combine the superior accuracy and feasibility-seeking behavior of gradient-based local NLP solvers with the global optimization abilities of OptQuest. Computational results include 155 smooth NLP and mixed integer nonlinear program (MINLP) problems due to Floudas et al. (1999), most with both linear and nonlinear constraints, coded in the GAMS modeling language. Some are quite large for global optimization, with over 100 variables and 100 constraints. Global solutions to almost all problems are found in a small number of local solver calls, often one or two.
631 citations
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Cornell University1, California Institute of Technology2, Jet Propulsion Laboratory3, Imperial College London4, Spanish National Research Council5, University of La Laguna6, University of Edinburgh7, UK Astronomy Technology Centre8, University of Colorado Boulder9, University of California, Irvine10, University of Sussex11, University of Pennsylvania12, European Space Agency13, Goddard Space Flight Center14, University of Paris-Sud15, Paris Diderot University16, Aix-Marseille University17, University of Cambridge18, Virginia Tech19, University of Padua20, Institut d'Astrophysique de Paris21, Harvard University22, University of British Columbia23, University of Minnesota24, Japan Aerospace Exploration Agency25, University College London26, Johns Hopkins University27
TL;DR: Despite the overall downturn in cosmic star formation towards the highest redshifts, it seems that environments mature enough to form the most massive, intense starbursts existed at least as early as 880 million years after the Big Bang.
Abstract: Massive present-day early-type (elliptical and lenticular) galaxies probably gained the bulk of their stellar mass and heavy elements through intense, dust-enshrouded starbursts--that is, increased rates of star formation--in the most massive dark-matter haloes at early epochs. However, it remains unknown how soon after the Big Bang massive starburst progenitors exist. The measured redshift (z) distribution of dusty, massive starbursts has long been suspected to be biased low in z owing to selection effects, as confirmed by recent findings of systems with redshifts as high as ~5 (refs 2-4). Here we report the identification of a massive starburst galaxy at z = 6.34 through a submillimetre colour-selection technique. We unambiguously determined the redshift from a suite of molecular and atomic fine-structure cooling lines. These measurements reveal a hundred billion solar masses of highly excited, chemically evolved interstellar medium in this galaxy, which constitutes at least 40 per cent of the baryonic mass. A `maximum starburst' converts the gas into stars at a rate more than 2,000 times that of the Milky Way, a rate among the highest observed at any epoch. Despite the overall downturn in cosmic star formation towards the highest redshifts, it seems that environments mature enough to form the most massive, intense starbursts existed at least as early as 880 million years after the Big Bang.
631 citations
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TL;DR: It is indicated that risk variants for psychiatric disorders aggregate in particular biological pathways and that these pathways are frequently shared between disorders.
Abstract: Genome-wide association studies (GWAS) of psychiatric disorders have identified multiple genetic associations with such disorders, but better methods are needed to derive the underlying biological mechanisms that these signals indicate. We sought to identify biological pathways in GWAS data from over 60,000 participants from the Psychiatric Genomics Consortium. We developed an analysis framework to rank pathways that requires only summary statistics. We combined this score across disorders to find common pathways across three adult psychiatric disorders: schizophrenia, major depression and bipolar disorder. Histone methylation processes showed the strongest association, and we also found statistically significant evidence for associations with multiple immune and neuronal signaling pathways and with the postsynaptic density. Our study indicates that risk variants for psychiatric disorders aggregate in particular biological pathways and that these pathways are frequently shared between disorders. Our results confirm known mechanisms and suggest several novel insights into the etiology of psychiatric disorders.
630 citations
Authors
Showing all 49233 results
Name | H-index | Papers | Citations |
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Yi Chen | 217 | 4342 | 293080 |
Robert J. Lefkowitz | 214 | 860 | 147995 |
Rob Knight | 201 | 1061 | 253207 |
Charles A. Dinarello | 190 | 1058 | 139668 |
Jie Zhang | 178 | 4857 | 221720 |
David Haussler | 172 | 488 | 224960 |
Bradley Cox | 169 | 2150 | 156200 |
Gang Chen | 167 | 3372 | 149819 |
Rodney S. Ruoff | 164 | 666 | 194902 |
Menachem Elimelech | 157 | 547 | 95285 |
Jay Hauser | 155 | 2145 | 132683 |
Robert E. W. Hancock | 152 | 775 | 88481 |
Robert Plomin | 151 | 1104 | 88588 |
Thomas E. Starzl | 150 | 1625 | 91704 |
Rajesh Kumar | 149 | 4439 | 140830 |