12 research outputs found
Pressure-dependent water absorption cross sections for exoplanets and other atmospheres
Many atmospheres (cool stars, brown dwarfs, giant planets, extrasolar planets) are predominately composed of molecular hydrogen and helium. H216O is one of the best measured molecules in extrasolar planetary atmospheres to date and a major compound in the atmospheres of brown-dwarfs and oxygen-rich cool stars, yet the scope of experimental and theoretical studies on the pressure broadening of water vapour lines by collision with hydrogen and helium remains limited. Theoretical H2- and He-broadening parameters of water vapour lines (rotational quantum number J up to 50) are obtained for temperatures in the range 300â2000 K. Two approaches for calculation of line widths were used: (i) the averaged energy difference method and (ii) the empirical expression for JâČJâł-dependence. Voigt profiles based on these widths and the BT2 line list are used to generate high resolution (View the MathML source) pressure broadened cross sections for a fixed range of temperatures and pressures between 300 and 2000 K and 0.001â10 bar. An interpolation procedure which can be used to determine cross sections at intermediate temperature and pressure is described. Pressure broadening parameters and cross sections are presented in new ExoMol format
The HITRAN2020 molecular spectroscopic database
The HITRAN database is a compilation of molecular spectroscopic parameters. It was established in the early 1970s and is used by various computer codes to predict and simulate the transmission and emission of light in gaseous media (with an emphasis on terrestrial and planetary atmospheres). The HITRAN compilation is composed of five major components: the line-by-line spectroscopic parameters required for high-resolution radiative-transfer codes, experimental infrared absorption cross-sections (for molecules where it is not yet feasible for representation in a line-by-line form), collision-induced absorption data, aerosol indices of refraction, and general tables (including partition sums) that apply globally to the data. This paper describes the contents of the 2020 quadrennial edition of HITRAN. The HITRAN2020 edition takes advantage of recent experimental and theoretical data that were meticulously validated, in particular, against laboratory and atmospheric spectra. The new edition replaces the previous HITRAN edition of 2016 (including its updates during the intervening years). All five components of HITRAN have undergone major updates. In particular, the extent of the updates in the HITRAN2020 edition range from updating a few lines of specific molecules to complete replacements of the lists, and also the introduction of additional isotopologues and new (to HITRAN) molecules: SO, CH3F, GeH4, CS2, CH3I and NF3. Many new vibrational bands were added, extending the spectral coverage and completeness of the line lists. Also, the accuracy of the parameters for major atmospheric absorbers has been increased substantially, often featuring sub-percent uncertainties. Broadening parameters associated with the ambient pressure of water vapor were introduced to HITRAN for the first time and are now available for several molecules. The HITRAN2020 edition continues to take advantage of the relational structure and efficient interface available at www.hitran.org and the HITRAN Application Programming Interface (HAPI). The functionality of both tools has been extended for the new edition
Accelerated inbreeding depression suggests synergistic epistasis for deleterious mutations in Drosophila melanogaster
Epistasis may have important consequences for a number of issues in quantitative genetics and evolutionary biology. In
particular, synergistic epistasis for deleterious alleles is relevant to the mutation load paradox and the evolution of sex and
recombination. Some studies have shown evidence of synergistic epistasis for spontaneous or induced deleterious mutations
appearing in mutation-accumulation experiments. However, many newly arising mutations may not actually be segregating
in natural populations because of the erasing action of natural selection. A demonstration of synergistic epistasis for naturally
segregating alleles can be achieved by means of inbreeding depression studies, as deleterious recessive allelic effects are
exposed in inbred lines. Nevertheless, evidence of epistasis from these studies is scarce and controversial. In this paper, we
report the results of two independent inbreeding experiments carried out with two different populations of Drosophila
melanogaster. The results show a consistent accelerated inbreeding depression for fitness, suggesting synergistic epistasis
among deleterious alleles. We also performed computer simulations assuming different possible models of epistasis and
mutational parameters for fitness, finding some of them to be compatible with the results observed. Our results suggest that
synergistic epistasis for deleterious mutations not only occurs among newly arisen spontaneous or induced mutations, but
also among segregating alleles in natural populationsWe acknowledge the support by Uvigo
Marine Research Centre funded by the âExcellence in Research
(INUGA)â Programme from the Regional Council of Culture, Education and Universities, with co-funding from the European Union
through the ERDF Operational Programme Galicia 2014-2020. This
work was funded by Agencia Estatal de InvestigacioÌn (AEI) (CGL2016-75904-C2-1-P), Xunta de Galicia (ED431C 2016-037) and
Fondos Feder: âUnha maneira de facer Europa.â SD was founded by a
predoctoral (FPI) grant from Ministerio de EconomĂa y
Competitividad, SpainS
The Genera of Fungi - fixing the application of the type species of generic names - G 2: Allantophomopsis, Latorua, Macrodiplodiopsis, Macrohilum, Milospium, Protostegia, Pyricularia, Robillarda, Rotula, Septoriella, Torula, and Wojnowicia
The present paper represents the second contribution in the Genera of Fungi series, linking type species
of fungal genera to their morphology and DNA sequence data, and where possible, ecology. This paper focuses on
12 genera of microfungi, 11 of which the type species are neo- or epitypified here: Allantophomopsis (A. cytisporea,
Phacidiaceae, Phacidiales, Leotiomycetes), Latorua gen. nov. (Latorua caligans, Latoruaceae, Pleosporales,
Dothideomycetes), Macrodiplodiopsis (M. desmazieri, Macrodiplodiopsidaceae, Pleosporales, Dothideomycetes),
Macrohilum (M. eucalypti, Macrohilaceae, Diaporthales, Sordariomycetes), Milospium (M. graphideorum,
incertae sedis, Pezizomycotina), Protostegia (P. eucleae, Mycosphaerellaceae, Capnodiales, Dothideomycetes),
Pyricularia (P. grisea, Pyriculariaceae, Magnaporthales, Sordariomycetes), Robillarda (R. sessilis, Robillardaceae,
Xylariales, Sordariomycetes), Rutola (R. graminis, incertae sedis, Pleosporales, Dothideomycetes), Septoriella
(S. phragmitis, Phaeosphaeriaceae, Pleosporales, Dothideomycetes), Torula (T. herbarum, Torulaceae,
Pleosporales, Dothideomycetes) and Wojnowicia (syn. of Septoriella, S. hirta, Phaeosphaeriaceae, Pleosporales,
Dothideomycetes). Novel species include Latorua grootfonteinensis, Robillarda africana, R. roystoneae, R. terrae,
Torula ficus, T. hollandica, and T. masonii spp. nov., and three new families: Macrodiplodiopsisceae, Macrohilaceae,
and Robillardaceae. Authors interested in contributing accounts of individual genera to larger multi-authored papers
to be published in IMA Fungus, should contact the associate editors listed for the major groups of fungi on the List
of Protected Generic Names for FungiThe Austrian
Science Fund (FWF; project P25870-B16)http://www.generaoffungi.orgam201