8,060 research outputs found

    Inversion algorithms for the microwave remote sensing of soil moisture. Experiments with swept frequency microwaves

    Get PDF
    Two experiments were performed employing swept frequency microwaves for the purpose of investigating the reflectivity from soil volumes containing both discontinuous and continuous changes in subsurface soil moisture content. Discontinuous moisture profiles were artificially created in the laboratory while continuous moisture profiles were induced into the soil of test plots by the environment of an agricultural field. The reflectivity for both the laboratory and field experiments was measured using bi-static reflectometers operated over the frequency ranges of 1.0 to 2.0 GHz and 4.0 to 8.0 GHz. Reflectivity models that considered the discontinuous and continuous moisture profiles within the soil volume were developed and compared with the results of the experiments. This comparison shows good agreement between the smooth surface models and the measurements. In particular the comparison of the smooth surface multi-layer model for continuous moisture profiles and the yield experiment measurements points out the sensitivity of the specular component of the scattered electromagnetic energy to the movement of moisture in the soil

    Data documentation for the bare soil experiment at the University of Arkansas

    Get PDF
    The reflectivities of several controlled moisture test plots were investigated. These test plots were of a similar soil texture which was clay loam and were prepared to give a desired initial soil moisture and density profile. Measurements were conducted on the plots as the soil water redistributed for both long term and diurnal cycles. These measurements included reflectivity, gravimetric and volumetric soil moisture, soil moisture potential, and soil temperature

    Mitoxantrone is superior to doxorubicin in a multiagent weekly regimen for patients older than 60 with high-grade lymphoma: results of a BNLI randomized trial of PAdriaCEBO versus PMitCEBO

    Get PDF
    A prospective, multicenter, randomized trial was undertaken to compare the efficacy and toxicity of adriamycin with mitoxantrone within a 6-drug combination chemotherapy regimen for elderly patients (older than 60 years) with high-grade non-Hodgkin lymphoma (HGL) given for a minimum of 8 weeks. A total of 516 previously untreated patients aged older than 60 years were randomized to receive 1 of 2 anthracycline-containing regimens: adriamycin, 35 mg/m2 intravenously (IV) on day 1 (n = 259), or mitoxantrone, 7 mg/m2 IV on day 1 (n = 257); with prednisolone, 50 mg orally on days 1 to 14; cyclophosphamide, 300 mg/m2 IV on day 1; etoposide, 150 mg/m2 IV on day 1; vincristine, 1.4 mg/m2 IV on day 8; and bleomycin, 10 mg/m2 IV on day 8. Each 2-week cycle was administered for a minimum of 8 weeks in the absence of progression. Forty-three patients were ineligible for analysis. The overall and complete remission rates were 78% and 60% for patients receiving PMitCEBO and 69% and 52% for patients receiving PAdriaCEBO (P = .05, P = .12, respectively). Overall survival was significantly better with PMitCEBO than PAdriaCEBO (P = .0067). However, relapse-free survival was not significantly different (P = .16). At 4 years, 28% of PAdriaCEBO patients and 50% of PMitCEBO patients were alive (P = .0001). Ann Arbor stage III/IV, World Health Organization performance status 2-4, and elevated lactate dehydrogenase negatively influenced overall survival from diagnosis. In conclusion, the PMitCEBO 8-week combination chemotherapy regimen offers high response rates, durable remissions, and acceptable toxicity in elderly patients with HGL

    Indexed induction and coinduction, fibrationally.

    Get PDF
    This paper extends the fibrational approach to induction and coinduction pioneered by Hermida and Jacobs, and developed by the current authors, in two key directions. First, we present a sound coinduction rule for any data type arising as the final coalgebra of a functor, thus relaxing Hermida and Jacobs’ restriction to polynomial data types. For this we introduce the notion of a quotient category with equality (QCE), which both abstracts the standard notion of a fibration of relations constructed from a given fibration, and plays a role in the theory of coinduction dual to that of a comprehension category with unit (CCU) in the theory of induction. Second, we show that indexed inductive and coinductive types also admit sound induction and coinduction rules. Indexed data types often arise as initial algebras and final coalgebras of functors on slice categories, so our key technical results give sufficent conditions under which we can construct, from a CCU (QCE) U : E -> B, a fibration with base B/I that models indexing by I and is also a CCU (QCE)

    PERSPECTIVES - Digital Influences on Sexual Discourse in Disabled Populations

    Get PDF
    The industry of sex aids for disabled people has been growing and becoming more nuanced, both with workers who facilitate manual sex aid and within the growing market of automated sex aids. Agency in sexual expression is often seen as an able-bodied activity and automated sex aids have yet to be considered with due rigor for general populations, including disabled populations. Here, we employ the grounded methodological choice of using digitally mediated discourses by disabled people, service providers, and activists to guide our inquiry into conversations that we, as members of the scientific community have generally neglected. We report on the financial, legal, and health implications of emerging digital technology driven changes in the landscape of sexual discourse for disabled populations. We then call for further investigation into this neglected but vitally important topic.Keywords: Automated sex aids; sexuality and disability; digital activism; sexual agency; sexual health; scientific researc

    Review Of Recent Developments And Shortcomings In The Characterization Of Potential Atmospheric Ice Nuclei : Focus On The Tropics.

    Get PDF
    In this paper, we summarize the four main ice nucleating aerosol types: mineral dusts, bioaerosols, soot, and glassy organics, with the aim of demonstrating the limitations in scientifi c literature regarding their ice nucleation properties. Because the tropics are largely associated with marine environments, such as the Atlantic, Pacifi c, and Indian Oceans, they are potential source of ice nuclei, and therefore ice clouds can form in regions of high convective uplift. As a result, these particles are able to infl uence both the planet’s radiative force and its hydrological cycle. Due to our limited understanding of these effects, we would like to encourage the scientifi c community to increase its efforts to study and characterize the tropical aerosol particles that may function as ice nuclei. Through such efforts, we may reduce uncertainties in climate predictions, and improve our understanding of global warming in the hopes of fi nding potential solutions to these issues

    A Candidate Protoplanet in the Taurus Star Forming Region

    Full text link
    HST/NICMOS images of the class I protostar TMR-1 (IRAS04361+2547) reveal a faint companion with 10.0" = 1400 AU projected separation. The central protostar is itself resolved as a close binary with 0.31" = 42 AU separation, surrounded by circumstellar reflection nebulosity. A long narrow filament seems to connect the protobinary to the faint companion TMR-1C, suggesting a physical association. If the sources are physically related then we hypothesize that TMR-1C has been ejected by the protobinary. If TMR-1C has the same age and distance as the protobinary then current models indicate its flux is consistent with a young giant planet of several Jovian masses.Comment: 16 pages, 1 figure, Accepted by Astrophysical Journal Letters, Related information is available at http://www.extrasolar.co

    Boson-Fermion coherence in a spherically symmetric harmonic trap

    Full text link
    We consider the photoassociation of a low-density gas of quantum-degenerate trapped fermionic atoms into bosonic molecules in a spherically symmetric harmonic potential. For a dilute system and the photoassociation coupling energy small compared to the level separation of the trap, only those fermions in the single shell with Fermi energy are coupled to the bosonic molecular field. Introducing a collective pseudo-spin operator formalism we show that this system can then be mapped onto the Tavis-Cummings Hamiltonian of quantum optics, with an additional pairing interaction. By exact diagonalization of the Hamiltonian, we examine the ground state and low excitations of the Bose-Fermi system, and study the dynamics of the coherent coupling between atoms and molecules. In a semiclassical description of the system, the pairing interaction between fermions is shown to result in a self-trapping transition in the photoassociation, with a sudden suppression of the coherent oscillations between atoms and molecules. We also show that the full quantum dynamics of the system is dominated by quantum fluctuations in the vicinity of the self-trapping solution.Comment: 16 pages, 14 figure

    Perceptions towards risks involved in off-site construction in the integrated design & construction project delivery

    Get PDF
    This study aimed to address the gap in research regarding the application of integrated design and construction (IDC) project delivery into off-site construction Projects (OSC) within China. A questionnaire survey was designed and delivered to reach Chinese professionals in Architecture, Engineering, and Construction (AEC) disciplines to assess their risk perceptions

    Development of a low-maintenance measurement approach to continuously estimate methane emissions: a case study

    Get PDF
    The chemical breakdown of organic matter in landfills represents a significant source of methane gas (CH4). Current estimates suggest that landfills are responsible for between 3% and 19% of global anthropogenic emissions. The net CH4 emissions resulting from biogeochemical processes and their modulation by microbes in landfills are poorly constrained by imprecise knowledge of environmental constraints. The uncertainty in absolute CH4 emissions from landfills is therefore considerable. This study investigates a new method to estimate the temporal variability of CH4 emissions using meteorological and CH4 concentration measurements downwind of a landfill site in Suffolk, UK from July to September 2014, taking advantage of the statistics that such a measurement approach offers versus shorter-term, but more complex and instantaneously accurate, flux snapshots. Methane emissions were calculated from CH4 concentrations measured 700 m from the perimeter of the landfill with observed concentrations ranging from background to 46.4 ppm. Using an atmospheric dispersion model, we estimate a mean emission flux of 709 μg m−2 s−1 over this period, with a maximum value of 6.21 mg m−2 s−1, reflecting the wide natural variability in biogeochemical and other environmental controls on net site emission. The emissions calculated suggest that meteorological conditions have an influence on the magnitude of CH4 emissions. We also investigate the factors responsible for the large variability observed in the estimated CH4 emissions, and suggest that the largest component arises from uncertainty in the spatial distribution of CH4 emissions within the landfill area. The results determined using the low-maintenance approach discussed in this paper suggest that a network of cheaper, less precise CH4 sensors could be used to measure a continuous CH4 emission time series from a landfill site, something that is not practical using far-field approaches such as tracer release methods. Even though there are limitations to the approach described here, this easy, low-maintenance, low-cost method could be used by landfill operators to estimate time-averaged CH4 emissions and their impact downwind by simultaneously monitoring plume advection and CH4 concentrations
    corecore