The flora of Mediterranean ecosystems contains families with species having fully and under-developed embryos in their seeds. After-ripening for physiological dormancy release and smoke influence germination in many species. We investigated how after-ripening and embryo growth interact with smoke to influence the temporal dynamics of seedling emergence among fire ephemerals. Seeds were placed in the field and under standardized (50% relative humidity, 30°C) laboratory conditions to test the effects of summer conditions on physiological dormancy loss. Germination was tested with water or smoke compounds (smoke water, KAR1) at a simulated autumn/winter temperature (18/7°C). The timing and amount of seedling emergence with smoke was observed for seeds exposed to near-natural conditions. During summer, physiological dormancy was broken in all species, enabling germination at autumn/winter but not summer temperatures; no embryo growth occurred in seeds with under-developed embryos. At the start of the wet season, seedling emergence from seeds with fully developed embryos occurred earlier than from seeds with under-developed embryos. In a non-consistent manner among our study species, smoke and smoke compounds influenced the rate of embryo growth and amount of germination. Effects of smoke were noticeable in terms of number of emergents in the first emergence season. Among ecologically similar species, we have shown (1) that both thermal and embryo traits exclude germination in the summer, (2) how embryo size influences the timing of seedling emergence in autumn–winter, and (3) a reduced requirement for smoke in the second emergence season after a fire with a shift to reliance on seasonal cues for emergence.

Tall ironweed is a troublesome perennial weed that infests cool-season grass pastures in Kentucky. Field experiments were conducted in 2000 through 2003 to evaluate the efficacy of fall-applied herbicides on established tall ironweed following a midsummer mowing. Triclopyr-containing treatments showed the greatest suppression of tall ironweed 12 mo after treatment (MAT), across all years. With triclopyr at 0.56 and 0.63 kg/ha, tall ironweed control was 80% or greater in 2 of the 3 yr. Dicamba initially provided 87% control 8 MAT in 2 of 3 yr and declined to less than 60% 12 MAT. Tall ironweed shoot density was also reduced 66% or more 12 MAT with fall-applied triclopyr-containing treatments. In contrast, tall ironweed density increased approximately twofold in dicamba-treated plots between 8 to 12 MAT in all 3 yr. The impact of herbicide treatment on dry matter (DM) yield of spring-seeded red clover (Trifolium pratense L.), tall ironweed, and forage grasses was also evaluated. Red clover DM yield in the herbicide-treated plots in 2002 showed no significant differences from the untreated control. However, red clover DM yield in 2003 was lowest for the two triclopyr + clopyralid treatments, indicating a decrease in DM production compared with that of the nontreated control. Results indicated that fall-applied triclopyr-containing herbicides following a midsummer mowing is an effective program for removing tall ironweed from grass pastures, but further research is needed to evaluate the establishment of red clover following herbicide treatment.

Imidazoles present a tunable, versatile and economical platform for the development of novel liquid solvents and polymer membranes for CO2 capture. An overview of our studies in this area is presented, with emphasis on characterization of structure-property relationships in imidazole-based materials through both experimental and computational studies. To this end, a growing library of systematically varied imidazole compounds has been synthesized using only commercial available starting materials and straightforward reactions. Using this library of compounds, we have sought to understand and develop predictive models for thermophysical properties relating to process design, including: density, viscosity, vapor pressure, pKa and CO2 absorption capacity. Furthermore, we have discovered that imidazoles are stable in the presence of SO2 and can form reversible 1:1 adducts, which can be beneficial as SO2 is typically present at ppm levels alongside CO2 in flue gas from coal-fired power plants.

The electronic properties of ThO2 single crystals were studied using x-ray photoemission spectroscopy (XPS). The XPS results show that the Th 4f core level is in an oxidation state that is consistent with that expected for Th in ThO2. The effective Debye temperature is estimated from the temperature dependent photoemission intensities of the Th 4f core level over the temperature range of 290 to 360 K. A Debye temperature of 468±32 K has been determined.

Previous studies have shown that a deficiency in DNA damage repair is associated with increased cancer risk, and exposure to UV radiation is a major risk factor for the development of malignant melanoma. High density of common nevi (moles) is a major risk factor for cutaneous melanoma. A nevus may result from a mutation in a single UV-exposed melanocyte which failed to repair DNA damage in one or more critical genes. XRCC3 and XRCC5 may have an effect on nevus count through their function as components of DNA repair processes that may be involved directly or indirectly in the repair of DNA damage due to UV radiation. This study aims to test the hypothesis that the frequency of flat or raised moles is associated with polymorphism at or near these DNA repair genes, and that certain alleles are associated with less efficient DNA repair, and greater nevus density. Twins were recruited from schools in south eastern Queensland and were examined close to their 12th birthday. Nurses examined each individual and counted all moles on the entire body surface. A 10cM genome scan of 274 families (642 individuals) was performed and microsatellite polymorphisms in XRCC3 and adjacent to XRCC5 were also typed. Linkage and association of nevus count to these loci were tested simultaneously using a structural-equation modeling approach implemented in MX. There is weak evidence for linkage of XRCC5 to a QTL influencing raised mole count, and also weak association. There is also weak evidence for association between flat mole count and XRCC3. No tests were significant after correction for testing multiple alleles, nor were any of the tests for total association significant. If variation in XRCC3 or XRCC5 influences UV sensitivity, and indirectly affects nevus density, then the effects are small.