Symmetries of quasiplatonic Riemann surfaces

We state and prove a corrected version of a theorem of Singerman, which relates the existence of symmetries (anticonformal involutions) of a quasiplatonic Riemann surface $\mathcal S$ (one uniformised by a normal subgroup $N$ of finite index in a cocompact triangle group $\Delta$) to the properties of the group $G=\Delta/N$. We give examples to illustrate the revised necessary and sufficient conditions for the existence of symmetries, and we relate them to properties of the associated dessins d'enfants, or hypermaps

Determining Hybridization in Jack Pine and Lodgepole Pine from British Columbia

This study was conducted to find wood quality evidence of hybridization between jack pine (Pinus banksiana) and lodgepole pine (Pinus contorta var. latifolia) in northeast British Columbia (BC). To determine if wood and fiber traits could be used as distinguishing features among jack pine, lodgepole pine, and their hybrids, differences in morphology and wood and fiber traits were related to the genetic identity of each sample. Thirty samples each of pure lodgepole pine, pure jack pine, and potential hybrids were collected from the Prince George area of BC, the Smoky Lake area of Alberta, and the Fort Nelson region of BC, respectively. Two 10-mm cores (bark to bark) were taken from each tree and analyzed for fiber length and coarseness, microfibril angle (MFA), basic density, earlywood:latewood ratios, and cell dimensions. Needle and cone morphology was used to distinguish among species groups in the field. Based on genetically identified samples, the fiber traits that best differentiated among pure jack pine, lodgepole pine, and hybrids were MFA and cell area

The Effects of Mountain Pine Beetle Attack on Lodgepole Pine Wood Morphology and Chemistry: Implications for Wood and Fiber Quality

The mountain pine beetle, Dendroctonus ponderosae Hopkins, is currently devastating the lodgepole pine resource in western Canada, and in an attempt to circumvent the problem significant volumes of infested or dead wood are being harvested. In order to fully utilize the killed resource, it is crucial to understand how the pine beetle impacts wood quality. A thorough analysis of beetle-killed and sound lodgepole pine trees indicated that the infested sapwood and heartwood had substantial moisture loss, and that the moisture content decreased with increasing tree height when compared to sound wood. The infested wood was also shown to have a lower specific gravity than sound wood, and tended to decrease with increasing tree height. Chemical analysis indicated that the infested sapwood contained significantly lower concentrations of extractives when compared to sound sapwood, and that extractives content increased towards the crown. Additionally, the infested sapwood also had lower lignin and hemicellulose contents when compared to the sound sapwood. Wood permeability showed that infested sapwood was more permeable than sound sapwood, while the opposite was true for the heartwood, with the sound heartwood being more permeable than the infested heartwood. Permeability in both sapwood and heartwood varied with tree height and correlated with extractives content. These chemical and morphological changes significantly influence the quality of wood and fiber obtained from this substantial resource

MF2078

Paul D. Ohlenbusch, Michael R. Langemeier and Steve L. Watson, CRP evaluating the options, Kansas State University, March 1995

Sex-related differences in murine hepatic transcriptional and proteomic responses to TCDD

2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) is an environmental contaminant that produces myriad toxicities in most mammals. In rodents alone, there is a huge divergence in the toxicological response across species, as well as among different strains within a species. But there are also significant differences between males and females animals of a single strain. These differences are inconsistent across model systems: the severity of toxicity is greater in female rats than males, while male mice and guinea pigs are more sensitive than females. Because the specific events that underlie this difference remain unclear, we characterized the hepatic transcriptional response of adult male and female C57BL/6 mice to 500 mu g/kg TCDD at multiple time-points. The transcriptional profile diverged significantly between the sexes. Female mice demonstrated a large number of altered transcripts as early as 6 h following treatment, suggesting a large primary response. Conversely, male animals showed the greatest TCDD-mediated response 144 h following exposure, potentially implicating significant secondary responses. Nr1i3 was statistically significantly induced at all time-points in the sensitive male animals. This mRNA encodes the constitutive androstane receptor (CAR), a transcription factor involved in the regulation of xenobiotic metabolism, lipid metabolism, cell cycle and apoptosis. Surprisingly though, changes at the protein level (aside from the positive control, CYP1A1) were modest, with only FMO3 showing clear induction, and no genes with sex-differences. Thus, while male and female mice show transcriptional differences in their response to TCDD, their association with TCDD-induced toxicities remains unclear. (C) 2015 The Authors. Published by Elsevier Inc.Peer reviewe