Publications by authors named "W M Porch"

Background: People living with human immunodeficiency virus (HIV) often make highly personal decisions about whether or not to disclose their HIV status in the workplace.

Objective: We aimed to determine current practices that support people living with HIV to make workplace disclosure decisions and to understand factors that affect disclosure decision-making.

Methods: Ninety-four people who provide health, social and peer-based services responded to an on-line survey about their experiences supporting workplace disclosure decisions of employees living with HIV.

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Laser speckle can influence lidar measurements from a diffuse hard target. Atmospheric optical turbulence will also affect the lidar return signal. We present a numerical simulation that models the propagation of a lidar beam and accounts for both reflective speckle and atmospheric turbulence effects.

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Theoretical analysis of simulations of optical effects from the 1950 Canadian forest fires has revealed what conditions are necessary for large fires to cause blue moons and suns. This study shows how large fires can be used to improve our understanding of long range pollution transport on a global scale as well as the evolution of aerosol radiative effects so important to global climate studies. The most important aerosol characteristics are the initial submicron smoke particle concentration and areal extent of the fire and its effect on fire plume dispersion.

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Remotely sensed wind, temperature changes with height, and turbulence have been compared with in situ instrumentation using optical and acoustic techniques across and within valleys. These comparisons have provided data useful in the interpretation of spatial averages inherent in remote sensing with spatial and temporal representativity of point meteorological measurements in complex terrain. Of particular interest in this study was comparison of the optical turbulence derived index-of-refraction structure function C(n) with the acoustically derived temperature structure function C(T) over divergent scales across and within a valley.

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