20 research outputs found
Global fire emissions estimates during 1997-2016
Climate, land use, and other anthropogenic and natural drivers have the potential to influence fire dynamics in many regions. To develop a mechanistic understanding of the changing role of these drivers and their impact on atmospheric composition, long-term fire records are needed that fuse information from different satellite and in situ data streams. Here we describe the fourth version of the Global Fire Emissions Database (GFED) and quantify global fire emissions patterns during 1997-2016. The modeling system, based on the Carnegie-Ames-Stanford Approach (CASA) biogeochemical model, has several modifications from the previous version and uses higher quality input datasets. Significant upgrades include (1) new burned area estimates with contributions from small fires, (2) a revised fuel consumption parameterization optimized using field observations, (3) modifications that improve the representation of fuel consumption in frequently burning landscapes, and (4) fire severity estimates that better represent continental differences in burning processes across boreal regions of North America and Eurasia. The new version has a higher spatial resolution (0.25) and uses a different set of emission factors that separately resolves trace gas and aerosol emissions from temperate and boreal forest ecosystems. Global mean carbon emissions using the burned area dataset with small fires (GFED4s) were 2.21015 grams of carbon per year (Pg Cyr-1) during 1997-2016, with a maximum in 1997 (3.0 Pg C yr-1) and minimum in 2013 (1.8 Pg C yr-1). These estimates were 11% higher than our previous estimates (GFED3) during 1997-2011, when the two datasets overlapped. This net increase was the result of a substantial increase in burned area (37 %), mostly due to the inclusion of small fires, and a modest decrease in mean fuel consumption (-19 %) to better match estimates from field studies, primarily in savannas and grasslands. For trace gas and aerosol emissions, differences between GFED4s and GFED3 were often larger due to the use of revised emission factors. If small fire burned area was excluded (GFED4 without the s for small fires), average emissions were 1.5 Pg C yr-1. The addition of small fires had the largest impact on emissions in temperate North America, Central America, Europe, and temperate Asia. This small fire layer carries substantial uncertainties; improving these estimates will require use of new burned area products derived from high-resolution satellite imagery. Our revised dataset provides an internally consistent set of burned area and emissions that may contribute to a better understanding of multi-decadal changes in fire dynamics and their impact on the Earth system. GFED data are available from http://www.globalfiredata.org
SN 2011hw: Helium-Rich Circumstellar Gas and the Luminous Blue Variable to Wolf-Rayet Transition in Supernova Progenitors
We present optical photometry and spectroscopy of the peculiar Type IIn/Ibn
supernova SN2011hw. Its light curve exhibits a slower decline rate than normal
SNeIbc, with a peak absolute magnitude of -19.5 (unfiltered) and a secondary
peak of -18.3 mag (R). Spectra of SN2011hw are unusual compared to normal SN
types, most closely resembling the spectra of SNeIbn. We center our analysis on
comparing SN 2011hw to the well-studied TypeIbn SN2006jc. While the two SNe
have many important similarities, the differences are quite telling: compared
to SN2006jc, SN2011hw has weaker HeI and CaII lines and relatively stronger H
lines, its light curve has a higher luminosity and slower decline rate, and
emission lines associated with the progenitor's CSM are narrower. One can
reproduce the unusual continuum shape of SN2011hw with equal contributions of a
6000K blackbody and a spectrum of SN2006jc. We attribute this emission
component and many other differences between the two SNe to extra opacity from
a small amount of additional H in SN2011hw, analogous to the small H mass that
makes SNeIIb differ from SNeIb. Slower speeds in the CSM and elevated H content
suggest a connection between the progenitor of SN2011hw and the class of
Ofpe/WN9 stars, which have been associated with LBVs in their hot quiescent
phases between outbursts, and are H-poor - but not H-free like classical
Wolf-Rayet (WR) stars. We conclude that the similarities and differences
between SN2011hw and SN2006jc can be largely understood if their progenitors
exploded at different points in the transitional evolution from an LBV to a WR
star.Comment: 11 pages, 7 figures, submitted to MNRA
Cellule-type d'habitat rural
Marle Louis. Cellule-type d'habitat rural. In: Chantiers. Revue illustrée de la construction en Afrique du Nord, N°27, 1957. Habitat musulman I. pp. 12-13
Lettre de Louis XIV (roi de France) à Bernard-Hector de Marle de Versigny (intendant d'Auvergne) datée du 20 septembre 1682, à Versailles
Lettre de Louis XIV (roi de France) à Bernard-Hector de Marle de Versigny (intendant d'Auvergne) datée du 20 septembre 1682, à Versailles. In: Correspondance administrative sous le règne de Louis XIV, recueillie et mise en ordre par G. B. Depping. Tome IV et dernier. Travaux publics – Affaires religieuses – Protestants – Sciences, lettres et arts – Pièces diverses. Paris : Imprimerie nationale, 1855. pp. 604-605
Lettre de Louis XIV (roi de France) à Bernard-Hector de Marle de Versigny (intendant d'Auvergne) datée du 20 septembre 1682, à Versailles
Lettre de Louis XIV (roi de France) à Bernard-Hector de Marle de Versigny (intendant d'Auvergne) datée du 20 septembre 1682, à Versailles. In: Correspondance administrative sous le règne de Louis XIV, recueillie et mise en ordre par G. B. Depping. Tome IV et dernier. Travaux publics – Affaires religieuses – Protestants – Sciences, lettres et arts – Pièces diverses. Paris : Imprimerie nationale, 1855. pp. 604-605
Cité de Recasement de Ténès
Lathuilliere Marcel, Di Martino Nicolas, Marle Louis, Guion Paul, Vieilhescaze André. Cité de Recasement de Ténès. In: Chantiers. Revue illustrée de la construction en Afrique du Nord, N°27, 1957. Habitat musulman I. p. 15
Genetic diversity and population structure of locally adapted South African chicken lines : implications for conservation
In this study microsatellite markers were applied to investigate the genetic diversity and population structure of the six local chicken lines kept in the "Fowls for Africa" program, for better clarification of parameters for breed differentiation and genetic conservation of this valuable resource. The lines included the Black Australorp, Potchefstroom Koekoek, New Hampshire, Ovambo, Lebova- Venda and a Naked Neck line. Unbiased estimates for heterozygosity ranged from 50% in the Potchefstroom Koekoek to as high as 65% in the Naked Neck chickens. FIS values varied from as low as 0.16 for the Black Australorp line to as high as 0.35 for the Ovambo chickens. The FST values indicated moderate to high genetic differentiation between the Naked Neck and New Hampshire (0.11); Ovambo and Naked Neck lines (0.12), and Naked Neck and Lebowa- Venda (0.14). A total of 13% of the total genetic variation observed was between the chicken lines and 87% within the lines, supporting moderate genetic differentiation. Population structure was assessed using STRUCTURE where the Black Australorp was genetically best defined. Although six clusters for the different populations could be distinguished, the other lines were not as clearly defined, with individual birds tending to share more than one cluster. Results support a broad classification of these lines and further investigation of unique alleles is recommended for conservation of the lines within the program
Genetic diversity and population structure of locally adapted South African chicken lines : implications for conservation
In this study microsatellite markers were applied to investigate the genetic diversity and population structure of the six local chicken lines kept in the "Fowls for Africa" program, for better clarification of parameters for breed differentiation and genetic conservation of this valuable resource. The lines included the Black Australorp, Potchefstroom Koekoek, New Hampshire, Ovambo, Lebova- Venda and a Naked Neck line. Unbiased estimates for heterozygosity ranged from 50% in the Potchefstroom Koekoek to as high as 65% in the Naked Neck chickens. FIS values varied from as low as 0.16 for the Black Australorp line to as high as 0.35 for the Ovambo chickens. The FST values indicated moderate to high genetic differentiation between the Naked Neck and New Hampshire (0.11); Ovambo and Naked Neck lines (0.12), and Naked Neck and Lebowa- Venda (0.14). A total of 13% of the total genetic variation observed was between the chicken lines and 87% within the lines, supporting moderate genetic differentiation. Population structure was assessed using STRUCTURE where the Black Australorp was genetically best defined. Although six clusters for the different populations could be distinguished, the other lines were not as clearly defined, with individual birds tending to share more than one cluster. Results support a broad classification of these lines and further investigation of unique alleles is recommended for conservation of the lines within the program
Orléansville Cité d'urgence
Bize Georges, Ducollet Jacques, Lathuilliere Marcel, Di Martino Nicolas, Marle Louis, Seror Claude. Orléansville Cité d'urgence. In: Chantiers. Revue illustrée de la construction en Afrique du Nord, N°27, 1957. Habitat musulman I. pp. 16-17
Files from: Impact of soft skills awareness on self-efficacy in a transformational context
Data sheets and Data analyses for theabove mentioned article