359 research outputs found

    Nine years of rockfish surveys in the Strait of Juan de Fuca

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    For decades, biologists from the Seattle Aquarium have been informally monitoring bottom fish on rocky reefs in Neah Bay, Washington. Based on increasing concern over the long term stability of bottom fish populations in this area by both state and federal agencies, the Aquarium formalized monitoring in 2005 with diver-based video surveys to quantify bottom fish (rockfish and lingcod) diversity and abundance over time. Divers performed 100-meter video transects, devised to be non-invasive and repeatable, to assess diurnally active and relatively sessile bottom fishes over time. Transects were conducted in the Strait of Juan de Fuca each year in August from 2005-2013 at five permanently marked sites. Density and diversity of bottom fish species were determined by biologists counting fish via the archived video. Over the past nine years, there has been no significant difference in diversity and density of adult rockfish among sites or years, but there have been significant young of the year (YOY) rockfish recruitment events in 2006, 2008 and 2010, termed “jackpot recruitment events”. We also found that young of the year rockfish densities in the “jackpot” years were significantly correlated with lower sea surface temperatures. Rockfish recruitment may be generally poor because larval survival and settlement are dependent upon changing conditions such as climate, abundance of predators, oceanic currents, and chance events. Being long-lived allows the adult population to persist through many years of poor reproduction until a good recruitment year occurs, as in 2006, 2008 and 2010.This study may elucidate significant trends in rockfish diversity and abundance, that will influence long term management plans for rockfish conservation

    Strange Condition; Sociability

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    Two one-act plays presented at John Carroll University, October 10-13, 2002.https://collected.jcu.edu/plays/1129/thumbnail.jp

    Embodied Discourses of Literacy in the Lives of Two Preservice Teachers

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    This study examines the emerging teacher literacy identities of Ian and A.J., two preservice teachers in a graduate teacher education program in the United States. Using a poststructural feminisms theoretical framework, the study illustrates the embodiment of literacy pedagogy discourses in relation to the literacy courses’ discourse of comprehensive literacy and the literacy biographical discourses of Ian and A.J. The results of this study indicate the need to deconstruct how the discourse of comprehensive literacy limits how we, as literacy teacher educators, position, hear and respond to our preservice teachers and suggests the need for differentiation in our teacher education literacy courses

    The Atacama Cosmology Telescope: A Measurement of the Cosmic Microwave Background Power Spectrum at 148 and 218 GHz from the 2008 Southern Survey

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    We present measurements of the cosmic microwave background (CMB) power spectrum made by the Atacama Cosmology Telescope at 148 GHz and 218 GHz, as well as the cross-frequency spectrum between the two channels. Our results clearly show the second through the seventh acoustic peaks in the CMB power spectrum. The measurements of these higher-order peaks provide an additional test of the {\Lambda}CDM cosmological model. At l > 3000, we detect power in excess of the primary anisotropy spectrum of the CMB. At lower multipoles 500 < l < 3000, we find evidence for gravitational lensing of the CMB in the power spectrum at the 2.8{\sigma} level. We also detect a low level of Galactic dust in our maps, which demonstrates that we can recover known faint, diffuse signals.Comment: 19 pages, 13 figures. Submitted to ApJ. This paper is a companion to Hajian et al. (2010) and Dunkley et al. (2010

    Turbine Integrated Pitching System

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    The Cal Poly Wind Power Club (CPWP) tasked this senior project to design, manufacture, test, and deliver a mechanism to pitch the blades for their small-scale horizontal axis wind turbine. CPWP competes in the Collegiate Wind Competition (CWC) against schools across the country, and as such it was critical to comply with the provided competition rules in addition to the design requirement from CPWP. The purpose of the pitching mechanism is to improve the performance and efficiency of the wind turbine by allowing the blades to adjust angles with different wind speeds. Specifically, this project aimed to minimize hub size, minimize power draw, minimize axial depth, increase blade strength, decrease blade switch time, in addition to being a durable and lightweight mechanism. The mechanism was designed with safety and reliability in mind and has been integrated into the CPWP wind turbine. The system utilizes two actuators to push and pull a swashplate connected to a 4-bar linkage to create the rotational motion in order to effectively pitch the blades. The team used a combination of CAD software and physical prototypes to evaluate the effectiveness of the mechanism. All of the manufacturing was completed by the team in the Cal Poly machine shops using a combination of manual machines and CNC. In addition, the team conducted various component and mechanism testing, including full turbine wind tunnel tests to validate the design. The final product was delivered to CPWP in time for the CWC competition, where it was put to the test against other universities\u27 wind turbine designs

    The Atacama Cosmology Telescope: Data Characterization and Map Making

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    We present a description of the data reduction and mapmaking pipeline used for the 2008 observing season of the Atacama Cosmology Telescope (ACT). The data presented here at 148 GHz represent 12% of the 90 TB collected by ACT from 2007 to 2010. In 2008 we observed for 136 days, producing a total of 1423 hours of data (11 TB for the 148 GHz band only), with a daily average of 10.5 hours of observation. From these, 1085 hours were devoted to a 850 deg^2 stripe (11.2 hours by 9.1 deg) centered on a declination of -52.7 deg, while 175 hours were devoted to a 280 deg^2 stripe (4.5 hours by 4.8 deg) centered at the celestial equator. We discuss sources of statistical and systematic noise, calibration, telescope pointing, and data selection. Out of 1260 survey hours and 1024 detectors per array, 816 hours and 593 effective detectors remain after data selection for this frequency band, yielding a 38% survey efficiency. The total sensitivity in 2008, determined from the noise level between 5 Hz and 20 Hz in the time-ordered data stream (TOD), is 32 micro-Kelvin sqrt{s} in CMB units. Atmospheric brightness fluctuations constitute the main contaminant in the data and dominate the detector noise covariance at low frequencies in the TOD. The maps were made by solving the least-squares problem using the Preconditioned Conjugate Gradient method, incorporating the details of the detector and noise correlations. Cross-correlation with WMAP sky maps, as well as analysis from simulations, reveal that our maps are unbiased at multipoles ell > 300. This paper accompanies the public release of the 148 GHz southern stripe maps from 2008. The techniques described here will be applied to future maps and data releases.Comment: 20 pages, 18 figures, 6 tables, an ACT Collaboration pape

    Imaging Renal Urea Handling in Rats at Millimeter Resolution using Hyperpolarized Magnetic Resonance Relaxometry

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    \textit{In vivo} spin spin relaxation time (T2T_2) heterogeneity of hyperpolarized \textsuperscript{13}C urea in the rat kidney was investigated. Selective quenching of the vascular hyperpolarized \textsuperscript{13}C signal with a macromolecular relaxation agent revealed that a long-T2T_2 component of the \textsuperscript{13}C urea signal originated from the renal extravascular space, thus allowing the vascular and renal filtrate contrast agent pools of the \textsuperscript{13}C urea to be distinguished via multi-exponential analysis. The T2T_2 response to induced diuresis and antidiuresis was performed with two imaging agents: hyperpolarized \textsuperscript{13}C urea and a control agent hyperpolarized bis-1,1-(hydroxymethyl)-1-\textsuperscript{13}C-cyclopropane-2H8^2\textrm{H}_8. Large T2T_2 increases in the inner-medullar and papilla were observed with the former agent and not the latter during antidiuresis suggesting that T2T_2 relaxometry may be used to monitor the inner-medullary urea transporter (UT)-A1 and UT-A3 mediated urea concentrating process. Two high resolution imaging techniques - multiple echo time averaging and ultra-long echo time sub-2 mm3^3 resolution 3D imaging - were developed to exploit the particularly long relaxation times observed
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