1,338 research outputs found
Scale of pluton/wall rock interaction near May Lake, Yosemite National Park, California, USA
The western outer granodiorite of the Tuolumne Intrusive Suite intruded a variety of metasedimentary wall rocks at 93.1 ± 0.1 Ma. The May Lake metamorphic screen (4500 x 550 m) is a remnant of the chemically diverse metasedimentary host rocks. Their chemical contrast with the invading pluton provides an excellent location to study pluton/wall rock interactions. Outside the screen, visible wall-rock xenoliths (mostly pelitic quartzite) are predominantly located in an elongate horizon surrounded by a hybridized fine-grained granodiorite. Initial Sr and Nd isotopic ratios of the hybridized granodiorite indicate incorporation of crustal material. Major- and trace-element geochemical data indicate contamination of the granodiorite with pelitic metasedimentary rocks occurred in two modes, selective assimilation of 1) a high-K partial-melt derived from pelitic quartzite, and 2) a low-K partial-melt derived from pelitic quartzite. However, there is little evidence for contamination of granodiorite beyond the immediate vicinity of wall rock inclusions
Re-evaluating pluton/volcano connections and igneous textures in light of incremental magma emplacement
Zircon U-Pb geochronologic data collected within the past ten years indicate that plutons are emplaced incrementally over time periods of 105 to 106 annum at magma accumulation rates on the order of 10-4-10-3 km3/a. Although incremental emplacement of magmas is now widely accepted, evaluation of the wide-ranging effects on pluton-volcano connections and the generation of magma diversity has just begun. Magma emplacement rates calculated for large ignimbrites (10-2 km3/a) are higher than most estimates for plutons (10-4-10-3 km3/a). Thermal models for magma emplacement in the crust predict this rate disparity and suggest that magma emplacement rates of 10-2 km3/a or greater are needed to produce large ignimbrites. Thus, there is a fundamental difference in the rates of accumulation of ignimbrite and pluton magmas but little is known on how individual magmatic centers behave. Geochemistry and U-Pb zircon data from the Mt. Princeton batholith and spatially associated ignimbrites in central Colorado indicate that the vast majority of the batholith was emplaced between periods of ignimbrite eruption at a rate of 1.6x10-3 km3/a. The temporal disconnect supports the hypothesis that ignimbrites are generated during periods of high magma flux, without significant fractionation in the upper crust and that plutons represent similar magmas that froze in the crust during periods of low magma flux. Thermal models and geochronology also indicate that pluton emplacement must be episodic with only small fractions (<5%) of mobile magma existing at any one time. The episodic emplacement of plutons also leads to temperature cycling of the magma, which is hypothesized to affect crystal textures. Experiments on crystal growth of ammonium thiocyanate in a magma analog at approximately 50ºC and plagioclase and olivine growth in an alkali basalt at approximately 1150ºC indicate that temperature cycling changes the texture of magmas dramatically; creating large crystals and decreasing crystal number density. Also, crystal alignment is observed in the magma analog experiments coincident with the thermal gradient. Together, these results indicate that temperature cycling of magmas can affect the crystal size distribution and fabric of the resultant rock and is a variable that needs to be assessed when interpreting igneous textures.Doctor of Philosoph
Surface Characterization of Red Maple Strands After Hot Water Extraction
The conversion of carbohydrates from wood to make biofuels such as ethanol is a topic of widespread interest. A promising approach is the removal of the hemicellulosic wood component by extraction with subsequent conversion to biofuels while continuing to produce forest products. The impact of extraction on wood strands for use in strand-based composites was investigated. One tree of red maple (Acer rubrum L.) was used to create strands 10.2 cm long with a thickness of 0.9 mm. Three hot water extraction procedures at 160°C, corresponding to severity factors (SF) of 2.71, 3.54, and 3.81, were used resulting in an average weight loss of 5.7, 16.9 and 18.1%, respectively. Scanning electron microscopic imaging of selected wood strands showed that pores in the cell wall increased as SF increased. The distribution and size of the cell-wall pore structure showed up to a 22.2% increase. The sessile drop method, using distilled water, diiodomethane, and ethylene glycol, indicated more pronounced liquid wetting and penetration as SF increased. Inverse gas chromatography led to the finding that dispersive surface-free energy and acid-base characteristics increase with SF. The extraction procedures should be kept below a SF of 3.54 to minimize changes in adhesion performance
The Grizzly, October 10, 1995
Diversity Committee Report • The Stolen Credit Card Conundrum • The Juice is Loose • Greek Service Requirements • Green Bringing Awareness to Campus • More Rules Change Pledging • Statement on Hazing • Circus Trial = Circus Ending • Debate: U.C. Sculptures • The Myth of Unity and Diversity • More Than a Protest? • Homosexuality: Not a Good Alternative • Intelligently Expressing Your Opinion? • Gossip, Responsibility, and Education • Failing Ourselves, Failing Others • Shackled by the Life Chain • The Not-so-Traditional Tradition: Is There Really a Fall Day? • No ID, No Cover Charge • Alumna Spotlight: Mary Harris • Trumpeter Mike Mossman to Lead Jazz Quintet at Ursinus • Sophomores To Focus On Campus Pride • Dr. Juan Espadas Receives Award • Team Loses to Widener and F&M • Ursinus Finishes Eighth at Susquehanna Fall Classic • Big Plays Doom Football Team • Streak Continues • Team Splits Conference Gameshttps://digitalcommons.ursinus.edu/grizzlynews/1365/thumbnail.jp
The Relationship Between GPS Sampling Interval and Estimated Daily Travel Distances in Chacma Baboons (Papio ursinus)
Modern studies of animal movement use the Global Positioning System (GPS) to estimate animals’ distance traveled. The temporal resolution of GPS fixes recorded should match those of the behavior of interest; otherwise estimates are likely to be inappropriate. Here, we investigate how different GPS sampling intervals affect estimated daily travel distances for wild chacma baboons (Papio ursinus). By subsampling GPS data collected at one fix per second for 143 daily travel distances (12 baboons over 11–12 days), we found that less frequent GPS fixes result in smaller estimated travel distances. Moving from a GPS frequency of one fix every second to one fix every 30 s resulted in a 33% reduction in estimated daily travel distance, while using hourly GPS fixes resulted in a 66% reduction. We then use the relationship we find between estimated travel distance and GPS sampling interval to recalculate published baboon daily travel distances and find that accounting for the predicted effect of sampling interval does not affect conclusions of previous comparative analyses. However, if short-interval or continuous GPS data—which are becoming more common in studies of primate movement ecology—are compared with historical (longer interval) GPS data in future work, controlling for sampling interval is necessary
LSST Science Book, Version 2.0
A survey that can cover the sky in optical bands over wide fields to faint
magnitudes with a fast cadence will enable many of the exciting science
opportunities of the next decade. The Large Synoptic Survey Telescope (LSST)
will have an effective aperture of 6.7 meters and an imaging camera with field
of view of 9.6 deg^2, and will be devoted to a ten-year imaging survey over
20,000 deg^2 south of +15 deg. Each pointing will be imaged 2000 times with
fifteen second exposures in six broad bands from 0.35 to 1.1 microns, to a
total point-source depth of r~27.5. The LSST Science Book describes the basic
parameters of the LSST hardware, software, and observing plans. The book
discusses educational and outreach opportunities, then goes on to describe a
broad range of science that LSST will revolutionize: mapping the inner and
outer Solar System, stellar populations in the Milky Way and nearby galaxies,
the structure of the Milky Way disk and halo and other objects in the Local
Volume, transient and variable objects both at low and high redshift, and the
properties of normal and active galaxies at low and high redshift. It then
turns to far-field cosmological topics, exploring properties of supernovae to
z~1, strong and weak lensing, the large-scale distribution of galaxies and
baryon oscillations, and how these different probes may be combined to
constrain cosmological models and the physics of dark energy.Comment: 596 pages. Also available at full resolution at
http://www.lsst.org/lsst/sciboo
The Long-Baseline Neutrino Experiment: Exploring Fundamental Symmetries of the Universe
The preponderance of matter over antimatter in the early Universe, the
dynamics of the supernova bursts that produced the heavy elements necessary for
life and whether protons eventually decay --- these mysteries at the forefront
of particle physics and astrophysics are key to understanding the early
evolution of our Universe, its current state and its eventual fate. The
Long-Baseline Neutrino Experiment (LBNE) represents an extensively developed
plan for a world-class experiment dedicated to addressing these questions. LBNE
is conceived around three central components: (1) a new, high-intensity
neutrino source generated from a megawatt-class proton accelerator at Fermi
National Accelerator Laboratory, (2) a near neutrino detector just downstream
of the source, and (3) a massive liquid argon time-projection chamber deployed
as a far detector deep underground at the Sanford Underground Research
Facility. This facility, located at the site of the former Homestake Mine in
Lead, South Dakota, is approximately 1,300 km from the neutrino source at
Fermilab -- a distance (baseline) that delivers optimal sensitivity to neutrino
charge-parity symmetry violation and mass ordering effects. This ambitious yet
cost-effective design incorporates scalability and flexibility and can
accommodate a variety of upgrades and contributions. With its exceptional
combination of experimental configuration, technical capabilities, and
potential for transformative discoveries, LBNE promises to be a vital facility
for the field of particle physics worldwide, providing physicists from around
the globe with opportunities to collaborate in a twenty to thirty year program
of exciting science. In this document we provide a comprehensive overview of
LBNE's scientific objectives, its place in the landscape of neutrino physics
worldwide, the technologies it will incorporate and the capabilities it will
possess.Comment: Major update of previous version. This is the reference document for
LBNE science program and current status. Chapters 1, 3, and 9 provide a
comprehensive overview of LBNE's scientific objectives, its place in the
landscape of neutrino physics worldwide, the technologies it will incorporate
and the capabilities it will possess. 288 pages, 116 figure
Pan-Cancer Analysis of lncRNA Regulation Supports Their Targeting of Cancer Genes in Each Tumor Context
Long noncoding RNAs (lncRNAs) are commonly dys-regulated in tumors, but only a handful are known toplay pathophysiological roles in cancer. We inferredlncRNAs that dysregulate cancer pathways, onco-genes, and tumor suppressors (cancer genes) bymodeling their effects on the activity of transcriptionfactors, RNA-binding proteins, and microRNAs in5,185 TCGA tumors and 1,019 ENCODE assays.Our predictions included hundreds of candidateonco- and tumor-suppressor lncRNAs (cancerlncRNAs) whose somatic alterations account for thedysregulation of dozens of cancer genes and path-ways in each of 14 tumor contexts. To demonstrateproof of concept, we showed that perturbations tar-geting OIP5-AS1 (an inferred tumor suppressor) andTUG1 and WT1-AS (inferred onco-lncRNAs) dysre-gulated cancer genes and altered proliferation ofbreast and gynecologic cancer cells. Our analysis in-dicates that, although most lncRNAs are dysregu-lated in a tumor-specific manner, some, includingOIP5-AS1, TUG1, NEAT1, MEG3, and TSIX, synergis-tically dysregulate cancer pathways in multiple tumorcontexts
Pan-cancer Alterations of the MYC Oncogene and Its Proximal Network across the Cancer Genome Atlas
Although theMYConcogene has been implicated incancer, a systematic assessment of alterations ofMYC, related transcription factors, and co-regulatoryproteins, forming the proximal MYC network (PMN),across human cancers is lacking. Using computa-tional approaches, we define genomic and proteo-mic features associated with MYC and the PMNacross the 33 cancers of The Cancer Genome Atlas.Pan-cancer, 28% of all samples had at least one ofthe MYC paralogs amplified. In contrast, the MYCantagonists MGA and MNT were the most frequentlymutated or deleted members, proposing a roleas tumor suppressors.MYCalterations were mutu-ally exclusive withPIK3CA,PTEN,APC,orBRAFalterations, suggesting that MYC is a distinct onco-genic driver. Expression analysis revealed MYC-associated pathways in tumor subtypes, such asimmune response and growth factor signaling; chro-matin, translation, and DNA replication/repair wereconserved pan-cancer. This analysis reveals insightsinto MYC biology and is a reference for biomarkersand therapeutics for cancers with alterations ofMYC or the PMN
Genomic, Pathway Network, and Immunologic Features Distinguishing Squamous Carcinomas
This integrated, multiplatform PanCancer Atlas study co-mapped and identified distinguishing
molecular features of squamous cell carcinomas (SCCs) from five sites associated with smokin
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