667 research outputs found

    Factors Determining Great Blue Heron Rookery Movement

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    The damaging effect of Great Blue Heron (Ardea herodias) excrement on nest trees was determined by observation and Hellige-Truog soil analysis methods. In large heronries high chemical concentrations kill nest trees and result in movement of heronry boundaries to o live tree area

    The Large-scale J=3-2 and J=2-1 CO Emission from M17 and its Implications for Extragalactic CO Observations

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    We observed a 10x20 pc region of the molecular cloud M17 in the 12CO and 13CO J=3-2 and J=2-1 transitions to determine their global behavior and to assess the reliability of using ratios of CO line intensities integrated over an entire cloud to determine the physical conditions within the cloud. Both the 12CO/13CO J=2-1 and J=3-2 line ratios correlate with the 13CO integrated intensity, with smaller line ratios observed at locations with large integrated intensities. This correlation is likely due to variations in the column density from one position to another within M17. The 12CO and 13CO (J=3-2/J=2-1) line ratios show no significant variation from place to place within M17, even on the peak of the photon-dominated region. A Large Velocity Gradient analysis of globally averaged line ratios gives results in reasonable agreement with the results obtained for individual lines-of-sight through the cloud, which suggests that the typical physical conditions in a molecular cloud can be determined using CO line ratios integrated over the entire cloud. There appears to be a clear trend of increasing 12CO/13CO J=2-1 and J=3-2 line ratios as one moves from Galactic molecular cloud cores to entire Galactic molecular clouds to normal galaxies. The most likely explanation of the high line ratios for normal galaxies is a significant contribution to the CO emission by low column density material, such as diffuse molecular clouds or the outer envelopes of giant molecular clouds.Comment: 26 pages, 6 figures, 2 tables. Accepted for publication in Ap

    Weakly dispersive modal pulse propagation in the North Pacific Ocean

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    Author Posting. © Acoustical Society of America, 2013. This article is posted here by permission of Acoustical Society of America or personal use, not for redistribution. The definitive version was published in Journal of the Acoustical Society of America 134 (2013): 3386, doi:10.1121/1.4820882.The propagation of weakly dispersive modal pulses is investigated using data collected during the 2004 long-range ocean acoustic propagation experiment (LOAPEX). Weakly dispersive modal pulses are characterized by weak dispersion- and scattering-induced pulse broadening; such modal pulses experience minimal propagation-induced distortion and are thus well suited to communications applications. In the LOAPEX environment modes 1, 2, and 3 are approximately weakly dispersive. Using LOAPEX observations it is shown that, by extracting the energy carried by a weakly dispersive modal pulse, a transmitted communications signal can be recovered without performing channel equalization at ranges as long as 500 km; at that range a majority of mode 1 receptions have bit error rates (BERs) less than 10%, and 6.5% of mode 1 receptions have no errors. BERs are estimated for low order modes and compared with measurements of signal-to-noise ratio (SNR) and modal pulse spread. Generally, it is observed that larger modal pulse spread and lower SNR result in larger BERs.This work was supported by the Office of Naval Research, Code 322, Grant Nos. N00014-06-1-0245, N00014-08-1-0195, and N00014-11-1-0194

    Modal analysis of the range evolution of broadband wavefields in the North Pacific Ocean : low mode numbers

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    Author Posting. © Acoustical Society of America, 2012. This article is posted here by permission of Acoustical Society of America for personal use, not for redistribution. The definitive version was published in Journal of the Acoustical Society of America 131 (2012): 4409-4427, doi:10.1121/1.4707431.The results of mode-processing measurements of broadband acoustic wavefields made in the fall of 2004 as part of the Long-Range Ocean Acoustic Propagation Experiment (LOAPEX) in the eastern North Pacific Ocean are reported here. Transient wavefields in the 50–90 Hz band that were recorded on a 1400 -m long 40 element vertical array centered near the sound channel axis are analyzed. This array was designed to resolve low-order modes. The wavefields were excited by a ship-suspended source at seven ranges, between approximately 50 and 3200 km, from the receiving array. The range evolution of broadband modal arrival patterns corresponding to fixed mode numbers (“modal group arrivals”) is analyzed with an emphasis on the second (variance) and third (skewness) moments. A theory of modal group time spreads is described, emphasizing complexities associated with energy scattering among low-order modes. The temporal structure of measured modal group arrivals is compared to theoretical predictions and numerical simulations. Theory, simulations, and observations generally agree. In cases where disagreement is observed, the reasons for the disagreement are discussed in terms of the underlying physical processes and data limitations.This work was supported by the Office of Naval Research, Code 322, Grant Nos. N00014-08-1-0195, N00014-06-1-0245, and N0014-11-1-0194

    Analysis of Deep Seafloor Arrivals observed on NPAL04

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    This report gives an overview of the analysis that was done on Deep Seafloor Arrivals since they were initially presented in Stephen et al (2009). All of the NPAL04/LOAPEX (North Pacific Acoustic Laboratory, 2004/ Long Range Ocean Acoustic Propagation Experiment) data on three ocean bottom seismometers (OBSs) at ~5,000m depth and the deepest element of the deep vertical line array (DVLA) at 4250m depth has been analyzed. A distinctive pattern of late arrivals was observed on the three OBSs for transmissions from T500 to T2300. The delays of these arrivals with respect to the parabolic equation predicted (PEP) path were the same for all ranges from 500 to 2300km, indicating that the delay was introduced near the receivers. At 500km range the same arrival was observed throughout the water column on the DVLA. We show that arrivals in this pattern converted from a PEP path to a bottom-diffracted surface reflected (BDSR) path at an off-geodesic seamount.Funding was provided by the Office of Naval Research under Contract No. N00014-10-1-0510

    Effectiveness of interventions to indirectly support food and drink intake in people with dementia : Eating and Drinking Well IN dementiA (EDWINA) systematic review

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    © 2016 Bunn et al. Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.BACKGROUND: Risks and prevalence of malnutrition and dehydration are high in older people but even higher in older people with dementia. In the EDWINA (Eating and Drinking Well IN dementiA) systematic review we aimed to assess effectiveness of interventions aiming to improve, maintain or facilitate food/drink intake indirectly, through food service or dining environment modification, education, exercise or behavioural interventions in people with cognitive impairment or dementia (across all settings, levels of care and support, types and degrees of dementia). METHODS: We comprehensively searched Medline and twelve further databases, plus bibliographies, for intervention studies with ≥3 cognitively impaired adult participants (any type/stage). The review was conducted with service user input in accordance with Cochrane Collaboration's guidelines. We duplicated assessment of inclusion, data extraction, and validity assessment, tabulating data. Meta-analysis (statistical pooling) was not appropriate so data were tabulated and synthesised narratively. RESULTS: We included 56 interventions (reported in 51 studies). Studies were small and there were no clearly effective, or clearly ineffective, interventions. Promising interventions included: eating meals with care-givers, family style meals, soothing mealtime music, constantly accessible snacks and longer mealtimes, education and support for formal and informal care-givers, spaced retrieval and Montessori activities, facilitated breakfast clubs, multisensory exercise and multicomponent interventions. CONCLUSIONS: We found no definitive evidence on effectiveness, or lack of effectiveness, of specific interventions but studies were small and short term. A variety of promising indirect interventions need to be tested in large, high-quality RCTs, and may be approaches that people with dementia and their formal or informal care-givers would wish to try. TRIAL REGISTRATION: The systematic review protocol was registered (CRD42014007611) and is published, with the full MEDLINE search strategy, on Prospero (http://www.crd.york.ac.uk/PROSPERO/display_record.asp?ID=CRD42014007611).Peer reviewedFinal Published versio

    A test of basin-scale acoustic thermometry using a large-aperture vertical array at 3250-km range in the eastern North Pacific Ocean

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    Author Posting. © Acoustical Society of America, 1999. This article is posted here by permission of Acoustical Society of America for personal use, not for redistribution. The definitive version was published in Journal of the Acoustical Society of America 105 (1999): 3185, doi:10.1121/1.424649.Broadband acoustic signals were transmitted during November 1994 from a 75-Hz source suspended near the depth of the sound-channel axis to a 700-m long vertical receiving array approximately 3250 km distant in the eastern North Pacific Ocean. The early part of the arrival pattern consists of raylike wave fronts that are resolvable, identifiable, and stable. The later part of the arrival pattern does not contain identifiable raylike arrivals, due to scattering from internal-wave-induced sound-speed fluctuations. The observed ray travel times differ from ray predictions based on the sound-speed field constructed using nearly concurrent temperature and salinity measurements by more than a priori variability estimates, suggesting that the equation used to compute sound speed requires refinement. The range-averaged oceansound speed can be determined with an uncertainty of about 0.05 m/s from the observed ray travel times together with the time at which the near-axial acoustic reception ends, used as a surrogate for the group delay of adiabatic mode 1. The change in temperature over six days can be estimated with an uncertainty of about 0.006 °C. The sensitivity of the travel times to ocean variability is concentrated near the ocean surface and at the corresponding conjugate depths, because all of the resolved ray arrivals have upper turning depths within a few hundred meters of the surface.This work was supported largely by the Strategic Environmental Research and Development Program through Defense Advanced Research Projects Agency ~DARPA! Grant No. MDA972-93- 1-0003. Additional support was provided at SIO by the Office of Naval Research ~ONR! through Grant No. N00014- 97-1-0258. J. Colosi wishes to acknowledge support from an ONR Young Investigator Award, from the J. Lamar Worzel Assistant Scientist Fund, and from the Penzance Endowed Fund in support of scientific staff at WHOI

    NPAL04 OBS data analysis part 1 : kinematics of deep seafloor arrivals

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    These notes provide supporting information for a JASA (Journal of the Acoustical Society of America) LttE (Letter to the Editor) manuscript, "Deep seafloor arrivals: A new class of arrivals in long-range ocean acoustic propagation" (Stephen et al., submitted). It addresses five issues raised by the co-authors: 1) incorrect processing for the time-compressed traces at T2300 and T3200 that appeared in an early version of the LttE (T2300, T3200 … refer to transmissions at 2300, 3200km etc from the DVLA (Deep Vertical Line Array)), 2) processing issues, including the trade-offs between coherent and incoherent stacking and corrections for the effects of moving sources and receivers and tidal currents (Doppler), 4) the distinction between "deep shadow zone arrivals", which occur below the turning points in Parabolic Equation (PE) models, and "deep seafloor arrivals", which appear dominantly on the Ocean Bottom Seismometer (OBS) but are either very weak or absent on the deepest element in the DVLA and do not coincide with turning points in the PE model (some of these OBS late arrivals occur after the finale region), 4) the role of surface-reflected bottomreflected (SRBR) paths in explaining the late arriving energy, and 5) generally reconciling the OBS analysis with work by other North Pacific Acoustic Laboratory (NPAL) investigators and Dushaw et al (1999).Funding was provided by the Office of Naval Research through Contract No. N00014-06-1-0222
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