Institution
University of California, Santa Cruz
Education•Santa Cruz, California, United States•
About: University of California, Santa Cruz is a education organization based out in Santa Cruz, California, United States. It is known for research contribution in the topics: Galaxy & Population. The organization has 15541 authors who have published 44120 publications receiving 2759983 citations. The organization is also known as: UCSC & UC, Santa Cruz.
Topics: Galaxy, Population, Star formation, Redshift, Planet
Papers published on a yearly basis
Papers
More filters
••
Oklahoma State University–Stillwater1, University of Sydney2, Macquarie University3, University of Utah4, Max Planck Society5, University of Alberta6, University of California, Irvine7, University of New Mexico8, University of Nebraska–Lincoln9, United States Geological Survey10, University of Washington11, University of Arizona12, University of Sheffield13, University of Tasmania14, ETH Zurich15, University of California, Davis16, Los Alamos National Laboratory17, Nanchang Institute of Technology18, University of Wyoming19, Swedish University of Agricultural Sciences20, University of Coimbra21, Northern Arizona University22, United States Forest Service23, Swiss Federal Institute for Forest, Snow and Landscape Research24, University of São Paulo25, University of Oxford26, University of California, Santa Cruz27, Humboldt State University28, Fordham University29, Centre national de la recherche scientifique30, University of Edinburgh31, Hobart Corporation32, Spanish National Research Council33, University of Chile34, Idaho State University35, University of Basilicata36, United States Department of Agriculture37, Colorado State University38, University of Montana39, University of Delaware40, Duke University41, University of Western Ontario42, Sonora Institute of Technology43, Pacific Northwest National Laboratory44
TL;DR: It is shown that, across multiple tree species, loss of xylem conductivity above 60% is associated with mortality, while carbon starvation is not universal, indicating that evidence supporting carbon starvation was not universal.
Abstract: Widespread tree mortality associated with drought has been observed on all forested continents and global change is expected to exacerbate vegetation vulnerability. Forest mortality has implications for future biosphere-atmosphere interactions of carbon, water and energy balance, and is poorly represented in dynamic vegetation models. Reducing uncertainty requires improved mortality projections founded on robust physiological processes. However, the proposed mechanisms of drought-induced mortality, including hydraulic failure and carbon starvation, are unresolved. A growing number of empirical studies have investigated these mechanisms, but data have not been consistently analysed across species and biomes using a standardized physiological framework. Here, we show that xylem hydraulic failure was ubiquitous across multiple tree taxa at drought-induced mortality. All species assessed had 60% or higher loss of xylem hydraulic conductivity, consistent with proposed theoretical and modelled survival thresholds. We found diverse responses in non-structural carbohydrate reserves at mortality, indicating that evidence supporting carbon starvation was not universal. Reduced non-structural carbohydrates were more common for gymnosperms than angiosperms, associated with xylem hydraulic vulnerability, and may have a role in reducing hydraulic function. Our finding that hydraulic failure at drought-induced mortality was persistent across species indicates that substantial improvement in vegetation modelling can be achieved using thresholds in hydraulic function.
651 citations
••
TL;DR: These compounds meet predicted criteria for disrupting Tcf/beta-catenin complexes and define a general standard to establish mechanism-based activity of small molecule inhibitors of this pathogenic protein-protein interaction.
651 citations
••
University of California, Santa Barbara1, Humboldt University of Berlin2, University of Southern California3, University of Chicago4, University of Erlangen-Nuremberg5, University of South Florida6, Yale University7, University of Cincinnati8, University of Georgia9, Syracuse University10, Smithsonian Institution11, Harvard University12, Natural History Museum13, Texas A&M University14, Pennsylvania State University15, University of Wisconsin-Madison16, Aix-Marseille University17, California State University, Fullerton18, University of California, Santa Cruz19, College of William & Mary20, University of Colorado Boulder21, Duke University22, Slovak Academy of Sciences23, University of North Carolina at Wilmington24
TL;DR: In this paper, a new data set of fossil occurrences representing 3.5 million specimens was presented, and it was shown that global and local diversity was less than twice as high in the Neogene as in the mid-Paleozoic.
Abstract: It has previously been thought that there was a steep Cretaceous and Cenozoic radiation of marine invertebrates. This pattern can be replicated with a new data set of fossil occurrences representing 3.5 million specimens, but only when older analytical protocols are used. Moreover, analyses that employ sampling standardization and more robust counting methods show a modest rise in diversity with no clear trend after the mid-Cretaceous. Globally, locally, and at both high and low latitudes, diversity was less than twice as high in the Neogene as in the mid-Paleozoic. The ratio of global to local richness has changed little, and a latitudinal diversity gradient was present in the early Paleozoic.
650 citations
••
University of Washington1, Institute for Advanced Study2, Princeton University3, University of California, Santa Cruz4, Fermilab5, Rensselaer Polytechnic Institute6, Joint Institute for Nuclear Astrophysics7, University of Texas at Austin8, Texas Tech University9, Australian National University10, Max Planck Society11, University of Ljubljana12, Lawrence Berkeley National Laboratory13, Johns Hopkins University14, Harvard University15, Austin Peay State University16, University of Tokyo17, Apache Corporation18, Pennsylvania State University19, University of Chicago20
TL;DR: In this article, a polynomial model for estimating the metallicity and rotational velocity distributions of SDSS spectra was proposed, which is similar to random and systematic uncertainties in spectroscopic determinations.
Abstract: In addition to optical photometry of unprecedented quality, the Sloan Digital Sky Survey (SDSS) is producing a massive spectroscopic database which already contains over 280,000 stellar spectra. Using eectiv e temperature and metallicity derived from SDSS spectra for 60,000 F and G type main sequence stars (0:2 < g r < 0:6), we develop polynomial models, reminiscent of traditional methods based on the UBV photometry, for estimating these parameters from the SDSS u g and g r colors. These estimators reproduce SDSS spectroscopic parameters with a root-mean-square scatter of 100 K for eectiv e temperature, and 0.2 dex for metallicity (limited by photometric errors), which are similar to random and systematic uncertainties in spectroscopic determinations. We apply this method to a photometric catalog of coadded SDSS observations and study the photometric metallicity distribution of 200,000 F and G type stars observed in 300 deg 2 of high Galactic latitude sky. These deeper (g < 20:5) and photometrically precise ( 0.01 mag) coadded data enable an accurate measurement of the unbiased metallicity distribution for a complete volume-limited sample of stars at distances between 500 pc and 8 kpc. The metallicity distribution can be exquisitely modeled using two components with a spatially varying number ratio, that correspond to disk and halo. The best-t number ratio of the two components is consistent with that implied by the decomposition of stellar counts proles into exponential disk and power-law halo components by Juri c et al. (2008). The two components also possess the kinematics expected for disk and halo stars. The metallicity of the halo component can be modeled as a spatially invariant Gaussian distribution with a mean of [F e=H] = 1:46 and a standard deviation of 0.3 dex. The disk metallicity distribution is non-Gaussian, with a remarkably small scatter (rms 0.16 dex) and the median smoothly decreasing with distance from the plane from 0:6 at 500 pc to 0:8 beyond several kpc. Similarly, we nd using proper motion measurements that a nonGaussian rotational velocity distribution of disk stars shifts by 50 km/s as the distance from the plane increases from 500 pc to several kpc. Despite this similarity, the metallicity and rotational velocity distributions of disk stars are not correlated (Kendall’s = 0:017 0:018). This absence of a correlation between metallicity and kinematics for disk stars is in a conict with the traditional decomposition in terms of thin and thick disks, which predicts a strong correlation ( = 0:30 0:04) at 1 kpc from the mid-plane. Instead, the variation of the metallicity and rotational velocity distributions can be modeled using non-Gaussian functions that retain their shapes and only shift as the distance from the mid-plane increases. We also study the metallicity distribution using a shallower (g < 19:5) but much larger sample of close to three million stars in 8500 sq. deg. of sky included in SDSS Data Release 6. The large sky coverage enables the detection of coherent substructures in the kinematics{ metallicity space, such as the Monoceros stream, which rotates faster than the LSR, and has a median metallicity of [F e=H] = 0:95, with an rms scatter of only 0.15 dex. We extrapolate our results to the performance expected from the Large Synoptic Survey Telescope (LSST) and estimate that LSST will obtain metallicity measurements accurate to 0.2 dex or better, with proper motion measurements accurate to 0.2-0.5 mas/yr, for about 200 million F/G dwarf stars within a distance limit of 100 kpc (g < 23:5). Subject headings: methods: data analysis | stars: statistics | Galaxy: halo, kinematics and dynamics, stellar content, structure
649 citations
••
TL;DR: A new tool is added that lets users interactively arrange existing graphing tracks into new groups and create a 30-way primate alignment on the human genome in the UCSC Genome Browser.
Abstract: The UCSC Genome Browser (https://genome.ucsc.edu) is a graphical viewer for exploring genome annotations. For almost two decades, the Browser has provided visualization tools for genetics and molecular biology and continues to add new data and features. This year, we added a new tool that lets users interactively arrange existing graphing tracks into new groups. Other software additions include new formats for chromosome interactions, a ChIP-Seq peak display for track hubs and improved support for HGVS. On the annotation side, we have added gnomAD, TCGA expression, RefSeq Functional elements, GTEx eQTLs, CRISPR Guides, SNPpedia and created a 30-way primate alignment on the human genome. Nine assemblies now have RefSeq-mapped gene models.
649 citations
Authors
Showing all 15733 results
Name | H-index | Papers | Citations |
---|---|---|---|
David J. Schlegel | 193 | 600 | 193972 |
David R. Williams | 178 | 2034 | 138789 |
John R. Yates | 177 | 1036 | 129029 |
David Haussler | 172 | 488 | 224960 |
Evan E. Eichler | 170 | 567 | 150409 |
Anton M. Koekemoer | 168 | 1127 | 106796 |
Mark Gerstein | 168 | 751 | 149578 |
Alexander S. Szalay | 166 | 936 | 145745 |
Charles M. Lieber | 165 | 521 | 132811 |
Jorge E. Cortes | 163 | 2784 | 124154 |
M. Razzano | 155 | 515 | 106357 |
Lars Hernquist | 148 | 598 | 88554 |
Aaron Dominguez | 147 | 1968 | 113224 |
Taeghwan Hyeon | 139 | 563 | 75814 |
Garth D. Illingworth | 137 | 505 | 61793 |