424 research outputs found
Angular distribution of photoelectrons ejected from HI by polarised coherent VUV radiation
No full textMank A, Drescher M, Huth-Fehre T, Schönhense G, Böwering N, Heinzmann U. Angular distribution of photoelectrons ejected from HI by polarised coherent VUV radiation. Journal of Physics, B: Atomic, Molecular and Optical Physics. 1989;22(17):L487-L491
Angle- and spin-resolved photoelectron spectroscopy in rotationally resolved photoionization of HI
No full textMank A, Drescher M, Brockhinke A, Böwering N, Heinzmann U. Angle- and spin-resolved photoelectron spectroscopy in rotationally resolved photoionization of HI. Zeitschrift für Physik D: Atoms, Molecules and Clusters. 1994;29(4):275-289
A laser-based coherent VUV source and its application to highly resolved studies of the Fano effect in HI
No full textHuth-Fehre T, Mank A, Drescher M, Böwering N, Heinzmann U. A laser-based coherent VUV source and its application to highly resolved studies of the Fano effect in HI. Physica Scripta. 1990;41(4):454-457
Scotochroides antennatus Mank
No full textScotochroides antennatus Mank NOVA SCOTIA: 26 specimens examined from Guysborough, Halifax, Lunenburg, Queens, Yarmouth, Kings, and Hants counties. The earliest record is from 1958 (Kings Co.: Kentville, 6.viii. 1958, J.R. Vockeroth, CNC). Newly recorded from Nova Scotia. In Nova Scotia, collected in Picea rubens, P. mariana (Mill.) BSP., Tsuga canadensis and Pinus strobus stands ranging in age from 40 to 120 + years; most specimens collected with flightintercept traps or by sweeping vegetation.Published as part of Majka, Christopher G. & Pollock, Darren A., 2006, Understanding saproxylic beetles: new records of Tetratomidae, Melandryidae, Synchroidae, and Scraptiidae from the Maritime Provinces of Canada (Coleoptera: Tenebrionoidea), pp. 45-68 in Zootaxa 1248 on page 55, DOI: 10.5281/zenodo.17297
Photoelectron emission from HI using narrow-band, polarized, coherent VUV-radiation
No full textHuth T, Mank A, Böwering N, Schönhense G, Wallenstein R, Heinzmann U. Photoelectron emission from HI using narrow-band, polarized, coherent VUV-radiation. In: Geddes J, ed. Electronic and atomic collisions: abstracts of contributed papers. Belfast: Ed.; 1987: 44
Photoelectron dynamics of HI ionized by coherent VUV radiation
No full textMank A, Drescher M, Huth-Fehre T, Schönhense G, Böwering N, Heinzmann U. Photoelectron dynamics of HI ionized by coherent VUV radiation. Journal of Electron Spectroscopy and Related Phenomena. 1990;52:661-670.The asymmetry parameter [beta] of the photoelectron angular distribution in photoionization of the molecule HI was measured using a tunable coherent VUV source. The target was cooled to a rotational temperature of less than 20 K by a supersonic beam expansion. The data show pronounced resonance structure which is compared to results on a target at nearly room temperature and to an ab-initio calculation by H. Lefebvre-Brion and coworkers
Positive selection underlies Faster-Z evolution of gene expression in birds.
No full textThe elevated rate of evolution for genes on sex chromosomes compared to autosomes (Fast-X or Fast-Z evolution) can result either from positive selection in the heterogametic sex, or from non-adaptive consequences of reduced relative effective population size. Recent work in birds suggests that Fast-Z of coding sequence is primarily due to relaxed purifying selection resulting from reduced relative effective population size. However, gene sequence and gene expression are often subject to distinct evolutionary pressures, therefore we tested for Fast-Z in gene expression using next-generation RNA-sequencing data from multiple avian species. Similar to studies of Fast-Z in coding sequence, we recover clear signatures of Fast-Z in gene expression, however in contrast to coding sequence, our data indicate that Fast-Z in expression is due to positive selection acting primarily in females. In the soma, where gene expression is highly correlated between the sexes, we detected Fast-Z in both sexes, although at a higher rate in females, suggesting that many positively selected expression changes in females are also expressed in males. In the gonad, where inter-sexual correlations in expression are much lower, we detected Fast-Z for female gene expression, but crucially, not males. This suggests that a large amount of expression variation is sex-specific in its effects within the gonad. Taken together, our results indicate that Fast-Z evolution of gene expression is the product of positive selection acting on recessive beneficial alleles in the heterogametic sex. More broadly, our analysis suggests that the adaptive potential of Z chromosome gene expression may be much greater than that of gene sequence, results which have important implications for the role of sex chromosomes in speciation and sexual selection
Independent stratum formation on the avian sex chromosomes reveals inter-chromosomal gene conversion and predominance of purifying selection on the w chromosome
No full textWe used a comparative approach spanning three species and 90 million years to study the evolutionary history of the avian sex chromosomes. Using whole transcriptomes, we assembled the largest cross-species dataset of W-linked coding content to date. Our results show that recombination suppression in large portions of the avian sex chromosomes has evolved independently, and that long-term sex chromosome divergence is consistent with repeated and independent inversions spreading progressively to restrict recombination. In contrast, over short-term periods we observe heterogeneous and locus specific divergence. We also uncover four instances of gene conversion between both highly diverged and recently evolved gametologs, suggesting a complex mosaic of recombination suppression across the sex chromosomes. Lastly, evidence from 16 gametologs reveal that the W chromosome is evolving with a significant contribution of purifying selection, consistent with previous findings that W-linked genes play an important role in encoding sex-specific fitness. This article is protected by copyright. All rights reserved
Giardia assemblage A: human genotype in muskoxen in the Canadian Arctic
No full textAs part of an ongoing program assessing the biodiversity and impacts of parasites in Arctic ungulates we examined 72 fecal samples from muskoxen on Banks Island, Northwest Territories, Canada for Giardia and Cryptosporidium. Cryptosporidium spp. were not detected, but 21% of the samples were positive for Giardia. Sequencing of four isolates of Giardia demonstrated G. duodenalis, Assemblage A, a zoonotic genotyp
Photoelectron spectroscopy of HI and photoemission following narrowband VUV excitation
No full textBöwering N, Huth T, Mank A, et al. Photoelectron spectroscopy of HI and photoemission following narrowband VUV excitation. In: Burke PG, West JB, eds. Electron-molecule scattering and photoionization: [proceedings of an Internat. Symposium on Electron-Molecule Scattering and Photoionization, held July 18 - 19, 1987, at SERC Daresbury Laboratory, Warrington, England]. Physics of atoms and molecules. New York [u.a.]: Plenum Pr.; 1988: 139-146
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