7,225 research outputs found

    Guidelines for the management of chronic obstructive pulmonary disease : Working group of the South African pulmonology society

    Get PDF
    Objective: This guideline has been developed in order to optimise the management of patients with chronic obstructive pulmonary disease (COPD) at all levels health care systems in South Africa. It contains an action plan for early recognition and appropriate treatment of this common condition.Options: Treatment regimens are recommended for patients with mild (stage I), and severe (stage III) disease.Outcomes: Optimal management of patients with COPD may achieve a reduction in breathlessness, improved quality of life, prevention of complications and limitation of disease progression.Evidence: The working Group comprised mainly pulmonologists, but included an anaesthetist, a pharmacologist and physiotherapist. Detailed literature review with particular attention to similar guideline documents from Europe and the USA was performed before the meeting.Recommendations: Steps in the management of patients with COPD include early recognition of the disease, smoking cessation, treatment of airflow obstruction with appropriate drugs (singly or in combination), education and pulmonary rehabilitation, and limitation of disease progression and complications. Detailed recommendations are made with regard to the use and interpretation of a trial of oral corticosteroid therapy. Indications for hospitalisation, intensive care unit admission and ventilatory support are provided.Validation: This guideline is similar to those recommended by other groups outside South Africa. It was developed by a working group of the South Africa Pulmonology Society and is endorsed by the Medical Association of South Africa.Sponsors: The meeting of the Working Group was sponsored by Boehringer Ingelheim. This sponsorship did not influence the activities of the Group

    Fuels treatment and wildfire effects on runoff from Sierra Nevada mixed-conifer forests

    Get PDF
    We applied an eco-hydrologic model (Regional Hydro-Ecologic Simulation System [RHESSys]), constrained with spatially distributed field measurements, to assess the impacts of forest-fuel treatments and wildfire on hydrologic fluxes in two Sierra Nevada firesheds. Strategically placed fuels treatments were implemented during 2011–2012 in the upper American River in the central Sierra Nevada (43 km2) and in the upper Fresno River in the southern Sierra Nevada (24 km2). This study used the measured vegetation changes from mechanical treatments and modelled vegetation change from wildfire to determine impacts on the water balance. The well-constrained headwater model was transferred to larger catchments based on geologic and hydrologic similarities. Fuels treatments covered 18% of the American and 29% of the Lewis catchment. Averaged over the entire catchment, treatments in the wetter central Sierra Nevada resulted in a relatively light vegetation decrease (8%), leading to a 12% runoff increase, averaged over wet and dry years. Wildfire with and without forest treatments reduced vegetation by 38% and 50% and increased runoff by 55% and 67%, respectively. Treatments in the drier southern Sierra Nevada also reduced the spatially averaged vegetation by 8%, but the runoff response was limited to an increase of less than 3% compared with no treatment. Wildfire following treatments reduced vegetation by 40%, increasing runoff by 13%. Changes to catchment-scale water-balance simulations were more sensitive to canopy cover than to leaf area index, indicating that the pattern as well as amount of vegetation treatment is important to hydrologic response

    A probabilistic approach to some results by Nieto and Truax

    Full text link
    In this paper, we reconsider some results by Nieto and Truax about generating functions for arbitrary order coherent and squeezed states. These results were obtained using the exponential of the Laplacian operator; more elaborated operational identities were used by Dattoli et al. \cite{Dattoli} to extend these results. In this note, we show that the operational approach can be replaced by a purely probabilistic approach, in the sense that the exponential of derivatives operators can be identified with equivalent expectation operators. This approach brings new insight about the kinks between operational and probabilistic calculus.Comment: 2nd versio

    Relativistic and Radiative Corrections to the Mollow Spectrum

    Get PDF
    The incoherent, inelastic part of the resonance fluorescence spectrum of a laser-driven atom is known as the Mollow spectrum [B. R. Mollow, Phys. Rev. 188, 1969 (1969)]. Starting from this level of description, we discuss theoretical foundations of high-precision spectroscopy using the resonance fluorescence light of strongly laser-driven atoms. Specifically, we evaluate the leading relativistic and radiative corrections to the Mollow spectrum, up to the relative orders of (Z alpha)^2 and alpha(Z alpha)^2, respectively, and Bloch-Siegert shifts as well as stimulated radiative corrections involving off-resonant virtual states. Complete results are provided for the hydrogen 1S-2P_{1/2} and 1S-2P_{3/2} transitions; these include all relevant correction terms up to the specified order of approximation and could directly be compared to experimental data. As an application, the outcome of such experiments would allow for a sensitive test of the validity of the dressed-state basis as the natural description of the combined atom-laser system.Comment: 20 pages, 1 figure; RevTe

    Calculation of some determinants using the s-shifted factorial

    Full text link
    Several determinants with gamma functions as elements are evaluated. This kind of determinants are encountered in the computation of the probability density of the determinant of random matrices. The s-shifted factorial is defined as a generalization for non-negative integers of the power function, the rising factorial (or Pochammer's symbol) and the falling factorial. It is a special case of polynomial sequence of the binomial type studied in combinatorics theory. In terms of the gamma function, an extension is defined for negative integers and even complex values. Properties, mainly composition laws and binomial formulae, are given. They are used to evaluate families of generalized Vandermonde determinants with s-shifted factorials as elements, instead of power functions.Comment: 25 pages; added section 5 for some examples of application

    Laplace transform of spherical Bessel functions

    Get PDF
    We provide a simple analytic formula in terms of elementary functions for the Laplace transform j_{l}(p) of the spherical Bessel function than that appearing in the literature, and we show that any such integral transform is a polynomial of order l in the variable p with constant coefficients for the first l-1 powers, and with an inverse tangent function of argument 1/p as the coefficient of the power l. We apply this formula for the Laplace transform of the memory function related to the Langevin equation in a one-dimensional Debye model.Comment: 5 pages LATEX, no figures. Accepted 2002, Physica Script
    • …
    corecore