PHOTOMORPHOGENESIS IN Penicillium isariaeforme: EXOGENOUS CALCIUM SUBSTITUTES FOR LIGHT

Abstract— Penicillium isariaeforme is a photomorphogenic fungus which produces upright bundles of conidia-bearing mycelia (called coremia) when grown on a defined medium in visible (450–500 nm) light. We found that exogenous Ca²⁺ ions could substitute for light. In the dark 1–2 m M Ca²⁺ triggered coremia formation. Dark induction of coremia was specific for Ca²⁺ in that it could not be duplicated by 50 m M Ba²⁺, Fe²⁺, Mg²⁺, Mn²⁺, Sr²⁺, or Zn²⁺. Additionally, light-induced coremia formation was inhibited by both KI (2.5 m M ) and phenylacetic acid (0.25 m M ).     

AN INDIVIDUAL‐BASED MODEL FOR FERAL HOGS IN GREAT SMOKY MOUNTAINS NATIONAL PARK

The expansion of feral hog (Sus scrofa) populations in the United States has resulted in increased efforts to develop and implement control strategies designed to minimize the impacts done by this invasive species. We describe an individual‐based model for feral hogs in Great Smoky Mountains National Park (GSMNP). The objectives of the model are to provide an understanding of the population dynamics of this feral hog population and to determine the efficacy of the annual harvest as a population control method. Results suggest that the dynamics of the population are driven by fall hard mast production and the GSMNP harvests currently limit growth of the population, but these control efforts have not reduced the population.     

A DUAL-BEAM SOURCE OF ACTINIC LIGHT FOR PHOTOSYNTHESIS RESEARCH

Abstract— A dual-beam source for providing illumination of white or nearly monochromatic light for photosynthesis studies is presented. The device provides programmed, repetitive sample illumination with variable intensity, pulse duration and sequence and a means of monitoring that program. It utilizes a lamp with an integral heat rejecting reflector, and a fiber optic bundle which efficiently transmits the light, diffusely and evenly illuminating the sample.     

Mathematical Modelling of Radiative Heat Exchanges in Czochralski Crystal Pulling

Crowley has published a mathematical model of the heat flowin Czochralski crystal pulling, assuming the surfaces of solidcrystal and liquid meniscus to be cooled by radiation to theatmosphere. An enhanced model is described that takes accountof the radiative heat exchanges between the atmosphere and thesurfaces of the crystal, the meniscus and the hot crucible wall. For computational purposes, the modelling of the radiative heatexchanges must be sufficiently simplified to allow frequentre-calculation of the relevant heat fluxes in the course ofa computer simulation of a Czochralski pulling experiment. Radiationoptics suggests a number of simplifications, which are explained.The geometry of the physical system, however, is not one forwhich standard results exist, and the techniques used to overcomethe consequent problems may be of interest in related contexts. The new model is compared numerically with the Crowley modelfor the case of germanium pulling; its sensitivity to variationof the height of the crucible wall, and its responses to variationof some other parameters are also illustrated.