30 Result(s)
within
Douglas A. Campbell
-
Article
Ultraviolet-B effects on photosystem II efficiency of natural phytoplankton communities from Antarctica
The impact of UVB on the Antarctic phytoplankton photosystem II repair cycle, involving the rapidly cycled D1 protein, was studied during summer 2002. On sunny and overcast days, phytoplankton (from 1-m depth)...
-
Article
Large reallocations of carbon, nitrogen, and photosynthetic reductant among phycobilisomes, photosystems, and Rubisco during light acclimation in Synechococcus elongatus strain PCC7942 are constrained in cells under low environmental inorganic carbon
Synechococcus elongatus strain PCC7942 cells were grown in high or low environmental concentrations of inorganic C (high-Ci, low-Ci) and subjected to a light shift from 50 µmol m−2 s−1 to 500 µmol m−2 s−1. We qua...
-
Article
Chlorosis during nitrogen starvation is altered by carbon dioxide and temperature status and is mediated by the ClpP1 protease in Synechococcus elongatus
The interactive effects of inorganic carbon status, temperature and light on chlorosis induced by nitrogen deficiency, and the roles of Clp proteases in this process were investigated. In wild-type cultures gr...
-
Article
Seasonal changes in temperature and light drive acclimation of photosynthetic physiology and macromolecular content in Lobaria pulmonaria
Lobaria pulmonaria (L.) Hoffm. is an epiphytic lichen common to temperate deciduous forests where it copes with large changes in temperature and light levels through repeated annual cycl...
-
Article
Origins of sulphate in Antarctic dry-valley soils as deduced from anomalous 17O compositions
The dry valleys of Antarctica are some of the oldest terrestrial surfaces on the Earth. Despite much study of soil weathering and development, ecosystem dynamics and the occurrence of life in these extreme env...
-
Article
Anomalous 17O compositions in massive sulphate deposits on the Earth
The variation of δ18O that results from nearly all physical, biological and chemical processes on the Earth is approximately twice as large as the variation of δ17O. This so-called ‘mass-dependent’ fractionation ...
-
Article
Endogenous Ethane and Ethylene Of Poa pratensis Leaf Blades and Leaf Chlorosis in Response to Biologically Active Products of Bipolaris sorokiniana
Infection of Poa pratensis leaf blades and callus tissue by Bipolaris sorokiniana increases the production of ethylene and ethane. The ethylene is responsible for most of the chlorosis that occurs during patho...
-
Article
Gaseous hydrocarbons associated with black layer induced by the interaction of cyanobacteria and Desulfovibrio desulfuricans†
Black layer is a condition of high-sand-content golf greens that results in a subsurface blackened layer in the sand produced by sulfate-reducing bacteria. Black layer can be the product of an interaction of c...
-
Article
Nutrient salts and the toxicity of black-layer induced by cyanobacteria and Desulfovibrio desulfuricans to Agrostis palustris
Cyanobacteria and Desulfovibrio desulfuricans can interact to form a subsurface black-layer in high-sand content golf greens that impairs internal water drainage and results in the decline of the Agrostis palu...
-
Article
Coincident chromosomal disomy in meiotic dyads from triploid yeast
Among meiotic asci produced by triploid (3N) Saccharomyces cerevisiae are cases in which exactly two of the four ascospores proliferate into colonies. Given the unique asymmetry problems inherent in distributing ...
