How to move ionized gas: an introduction to the dynamics of HII regions

This review covers the dynamic processes that are important in the evolution and structure of galactic HII regions, concentrating on an elementary presentation of the physical concepts and recent numerical simulations of HII region evolution in a non-uniform medium. The contents are as follows: (1) The equations (Euler equations; Radiative transfer; Rate equations; How to avoid the dynamics; How to avoid the atomic physics). (2) Physical concepts (Static photoionization equilibrium; Ionization front propagation; Structure of a D-type front; Photoablation flows; Other ingredients - Stellar winds, Radiation pressure, Magnetic fields, Instabilities). (3) HII region evolution (Early phases: hypercompact and ultracompact regions; Later phases: compact and extended regions; Clumps and turbulence).Comment: To be published as a chapter in 'Diffuse Matter from Star Forming Regions to Active Galaxies' - A volume Honouring John Dyson. Eds. T. W. Harquist, J. M. Pittard and S. A. E. G. Falle. 25 pages, 7 figures. Some figures degraded to meet size restriction. Full-resolution version available at http://www.ifront.org/wiki/Dyson_Festschrift_Chapte

High Oxygen Level in a Soaking Treatment Improves Early Root and Shoot Development of Black Willow Cuttings

Black willow (Salix nigra) stem cuttings are commonly used to stabilize eroded streambanks with survival dependent on rapid development of adventitious roots to maintain plant water balance, absorb nutrients, and provide anchorage and support especially during flood and drought events. Soaking cuttings in water prior to planting increases survival and growth rates, but it is not known whether oxygen content in the soaking water affects the rate of early root and shoot initiation and growth. A laboratory experiment tested the hypothesis that cuttings treated with high oxygen (>95% saturation, 8.62 mg O2 l-1) soaking exhibit more rapid initiation and growth of roots and shoots than cuttings treated with low oxygen (<15% saturation, 1.24 mg O2 l-1) soaking and control (unsoaked). Root initiation was enhanced in both high and low O2 soaking treatments compared to control (100, 93, and 41%, respectively, n = 27). High O2 soaking led to greater root length than low O2 soaking during the fourth week after planting (26.5 and 12.3 cm on day 22; 27.7 and 19.1 cm on day 27, respectively). Shoot growth was greater in high O2 compared to low O2 soaking on days 36 and 56 after planting (9.3 and 6.3 cm on day 36, 10.7 and 7.2 cm on day 56, respectively). Shoot and root biomass production was stimulated in both soaking treatments, with 200% more biomass production by day 59 compared to control. Results of this study demonstrated that a high oxygen soaking treatment has potential for improving early root and shoot growth, and survival in willow cuttings planted at riparian restoration sites

A note on Lindley's paradox

Lindley's paradox, p-value, Bayes estimates, point null hypothesis, robust, Bayesian analysis, Primary 62F03, 62F35, Secondary 62F15, 62C10,