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
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17 Jun 2007TL;DR: A new post-processing step is presented to enhance the resolution of range images, using one or two registered and potentially high-resolution color images as reference and iteratively refine the input low-resolution range image in terms of both its spatial resolution and depth precision.
Abstract: We present a new post-processing step to enhance the resolution of range images. Using one or two registered and potentially high-resolution color images as reference, we iteratively refine the input low-resolution range image, in terms of both its spatial resolution and depth precision. Evaluation using the Middlebury benchmark shows across-the-board improvement for sub-pixel accuracy. We also demonstrated its effectiveness for spatial resolution enhancement up to 100 times with a single reference image.
834 citations
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TL;DR: In this article, one-dimensional, convective, vertical structure models and one dimensional time-dependent, radial diffusion models are combined to create a selfconsistent picture in which FU Orionis outbursts occur in young stellar objects (YSOs) as the result of a large-scale, self-regulated, thermal ionization instability in the surrounding protostellar accretion disk.
Abstract: One-dimensional, convective, vertical structure models and one dimensional time-dependent, radial diffusion models are combined to create a self-consistent picture in which FU Orionis outbursts occur in young stellar objects (YSOs) as the result of a large-scale, self-regulated, thermal ionization instability in the surrounding protostellar accretion disk. Although active accretion disks have long been postulated to be ubiqitous among low-mass YSOs, few constraints have until now been imposed on physical conditions in these disks. By fitting the results of time-dependent disk models to observed timescales of FU Orionis events, we estimate the magnitude of the effective viscous stress in the inner disk (r approximately less than 1 AU) to be, in accordance with an ad hoc 'alpha' prescription, the product of the local sound speed, pressure scale height, and an efficiency factor alpha of 10(exp -4) where hydrogen is neutral and 10(exp 3) where hydrogen is ionized. We hypothesize that all YSOs receive infall onto their outer disks which is steady (or slowly declining with time) and that FU Orionis outbursts are self-regulated, disk outbursts which occur only in systems which transport matter inward at a rate sufficiently high to cause hydrogen to be ionized in the inner disk. We estimate a critical mass flux of dm(sub crit)/dt = 5 x 10(exp 7) solar mass/yr independent of the magnitude of alpha for systems with one solar mass, three solar radius central objects. Infall accretion rates in the range of dm(sub in)/dt = 1-10) x 10(exp -6) solar mass/yr produce observed FU Orionis timescales consistent with estimates of spherical molecular cloud core collapse rates. Modeled ionization fronts are typically initiated near the inner edge of the disk and propogate out to a distance of several tens of stellar radii. Beyond this region, the disk transports mass steadily inward at the supplied constant infall rate. Mass flowing through the innermost disk annulus is equal to dm(sub in)/dt only in a time-averaged sense and is regulated by the ionization of hydrogen in the inner disk such that long intervals (approximately 1000 yr) of low-mass flux: (1-30) x 10(exp -8) solar mass/yr are punctuated by short intervals (approximately 100 yr) of high-mass flux: (1-30) x 10(exp -5) solar mass/yr. Timescales and mass fluxes derived for quiescent and outburst stages are consistent with estimates from observations of T Tauri and FU Orionis systems, respectively.
832 citations
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TL;DR: In this article, the authors used a smooth particle hydrodynamics method to simulate colliding rocky and icy bodies from centimeter scale to hundreds of kilometers in diameter in an effort to define self-consistently the threshold for catastrophic disruption.
831 citations
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University of Washington1, University of Louisville2, Oregon State University3, Centre national de la recherche scientifique4, Lawrence Livermore National Laboratory5, Joint Genome Institute6, Michigan State University7, University of California, Santa Cruz8, Salk Institute for Biological Studies9, University of Illinois at Urbana–Champaign10, University of Oklahoma11, University of Oldenburg12, Northwestern University13, Woods Hole Oceanographic Institution14
TL;DR: The isolation of Candidatus “Nitrosopumilus maritimus” strain SCM1 is reported, revealing highly copper-dependent systems for ammonia oxidation and electron transport that are distinctly different from known ammonia-oxidizing bacteria.
Abstract: Ammonia-oxidizing archaea are ubiquitous in marine and terrestrial environments and now thought to be significant contributors to carbon and nitrogen cycling. The isolation of Candidatus “Nitrosopumilus maritimus” strain SCM1 provided the opportunity for linking its chemolithotrophic physiology with a genomic inventory of the globally distributed archaea. Here we report the 1,645,259-bp closed genome of strain SCM1, revealing highly copper-dependent systems for ammonia oxidation and electron transport that are distinctly different from known ammonia-oxidizing bacteria. Consistent with in situ isotopic studies of marine archaea, the genome sequence indicates N. maritimus grows autotrophically using a variant of the 3-hydroxypropionate/4-hydroxybutryrate pathway for carbon assimilation, while maintaining limited capacity for assimilation of organic carbon. This unique instance of archaeal biosynthesis of the osmoprotectant ectoine and an unprecedented enrichment of multicopper oxidases, thioredoxin-like proteins, and transcriptional regulators points to an organism responsive to environmental cues and adapted to handling reactive copper and nitrogen species that likely derive from its distinctive biochemistry. The conservation of N. maritimus gene content and organization within marine metagenomes indicates that the unique physiology of these specialized oligophiles may play a significant role in the biogeochemical cycles of carbon and nitrogen.
825 citations
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TL;DR: Some of the emerging rules that govern the highly context-dependent and combinatorial nature of alternative splicing regulation are described.
Abstract: Sequence-specific RNA-binding proteins (RBPs) bind to pre-mRNA to control alternative splicing, but it is not yet possible to read the 'splicing code' that dictates splicing regulation on the basis of genome sequence. Each alternative splicing event is controlled by multiple RBPs, the combined action of which creates a distribution of alternatively spliced products in a given cell type. As each cell type expresses a distinct array of RBPs, the interpretation of regulatory information on a given RNA target is exceedingly dependent on the cell type. RBPs also control each other's functions at many levels, including by mutual modulation of their binding activities on specific regulatory RNA elements. In this Review, we describe some of the emerging rules that govern the highly context-dependent and combinatorial nature of alternative splicing regulation.
820 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 |