Tilting chains of negative curves on rational surfaces

We introduce the notion of exact tilting objects, which are partial tilting objects $T$ inducing an equivalence between the abelian category generated by $T$ and the category of modules over the endomorphism algebra of $T$. Given a chain of sufficiently negative rational curves on a rational surface, we construct an exceptional sequence whose universal extension is an exact tilting object. For a chain of (-2)-curves, we obtain an equivalence with modules over a well known algebra.Comment: 13 page

Historical Changes and Future Trajectories of Deforestation in the Ituri-Epulu-Aru Landscape (Democratic Republic of the Congo)

International audienceThe Ituri-Epulu-Aru landscape (IEAL) is experiencing deforestation and forest degradation. This deforestation is at the root of many environmental disturbances in a region characterized by endemism in biodiversity. The importance of this article is to provide useful information for those who wish to discuss a model that can be replicated for other territories affected by deforestation and changes in natural and anthropogenic forest structure. This article focuses on the triangulation of spatialized prospective scenarios in order to identify future trajectories based on the knowledge of historical dynamics through the diachronic analysis of three satellite images (2003–2010–2014–2016). The scenarios were designed in a supervised model implemented in the DINAMICA EGO platform. The three scenarios: business as-usual (BAU), rapid economic growth (REG) and sustainable management of the environment (SME), extrapolating current trends, show that by 2061 this landscape will always be dominated forests (+84%). Old-growth forests occupy 74.2% of the landscape area in the BAU scenario, 81.4% in the SEM scenario and 61.2% in the REG scenario. The SEM scenario gives hope that restoration and preservation of biodiversity priority habitats is still possible if policy makers become aware of it

Using MALDI-TOF mass spectrometry to identify ticks collected on domestic and wild animals from the Democratic Republic of the Congo

International audienceMatrix-assisted laser desorption/ionization mass spectrometry (MALDI-TOF MS) has recently emerged as an alternative to morphological and molecular tools to identify tick species. In this study, we set out to evaluate and confirm the ability of MALDI-TOF MS to identify different species of ticks collected in the Democratic Republic of the Congo and preserved in 70% ethanol. A total of 575 ticks, of which 530 were collected from domestic pigs and 45 from wild animals, were subjected to MALDI-TOF MS analysis to evaluate the intraspecies reproducibility and interspecies specificity of MS profiles obtained from the different species. Morphologically, the ticks belonged to seven different species, namely Rhipicephalus complanatus , Rhipicephalus congolensis , Haemaphysalis muhsamae , Ixodes cumulatimpunctatus , Amblyomma exornatum , Amblyomma compressum and an unidentified Rhipicephalus sp. A total of 535/575 (93%) of the spectra obtained were of good enough quality to be used for our analyses. Our home-made MALDI-TOF MS arthropod database was upgraded with spectra obtained from between one and five randomly selected specimens per species. For these reference specimens, molecular identification of the ticks was also made using 16S, 12S rDNA genes and the Cox1 mtDNA gene sequencing. The remaining good quality spectra were then queried against the upgraded MALDI-TOF MS database, showing that 100% were in agreement with the morphological identification, with logarithmic score values (LSVs) between 1.813 and 2.51. The consistency between our morphological, molecular and MALDI-TOF MS identification confirms the capability and precision of MALDI-TOF MS for tick identification

Révision du genre Poeonoma Tams & Bowden (Lepidoptera : Noctuidae : Apameiini : Sesamiina) avec la description d’un nouveau genre et de deux nouvelles espèces de Sesamiina de la région afrotropicale

The genus Poeonoma (Tams & Bowden, 1953) is revised to include two species P. serrata (Hampson, 1910) and P. ugandensis Le Run. sp., from the Congolian bioregion. Several new synonyms are introduced for Poeonoma serrata: Conicofrontia sjoestedti (Aurivillius, 1925) n. syn. for Poeonoma serrata (Hampson, 1910), Poeonoma similis (Tams & Bowden, 1953) n. syn. for Poeonoma serrata (Hampson, 1910), and Poeonoma nigribasis (Laporte, 1974) n. syn. for Poeonoma serrata (Hampson, 1910). A new genus, Nyaluteme Le Run. gen., is proposed for two species formerly included in Poeonoma, N. acantha (Tams & Bowden, 1953) n. comb. and N. inermis (Laporte, 1973) n. comb., and N. nigra Le Run. sp., described from the Congolian bioregion. Host-plants for three of the species are recorded:Pennisetum purpureum Schumach. for P. serrata and P. ugandensis, and Miscanthus violaceus (K. Schum) Pilg. for N. nigra. A key to species, descriptions, illustrations of adults and genitalia, and distribution maps are included. Results of previously published phylogenetic analyses also allow the status of the new genus to be confirmed and to infer the phylogenetic placement of the two genera.Le genre Poeonoma (Tams & Bowden, 1953) est révisé ; deux espèces, P. serrata (Hampson, 1910) et P. ugandensis Le Ru n. sp., de la biorégion Congolaise, y sont incluses et plusieurs nouvelles synonymies sont proposées pour Poeonoma serrata : Conicofrontia sjoestedti (Aurivillius, 1925) n. syn. de Poeonoma serrata (Hampson, 1910), Poeonoma similis (Tams & Bowden, 1953) n. syn. de Poeonoma serrata (Hampson, 1910), et Poeonoma nigribasis (Laporte, 1974) n. syn. de Poeonoma serrata (Hampson, 1910). Un nouveau genre, Nyaluteme Le Ru n. gen., de la biorégion Congolaise, est proposé pour deux espèces précédemment décrites dans le genre Poeonoma, N. acantha (Tams & Bowden, 1953) n. comb., et N. inermis (Laporte, 1973) n. comb., et une espèce nouvellement décrite N. nigra Le Ru n. sp. Les plantes-hôtes de trois espèces sont répertoriées : Pennisetum purpureum Schumach. pour P. serrata et P. ugandensis, et Miscanthus violaceus (K. Schum) Pilg. pour N. nigra. Une clé de détermination des espèces est présentée ainsi que l’illustration des adultes et des génitalia et, des cartes de distribution. Les résultats d’analyses de reconstruction phylogénétique déjà publiées permettent également de confirmer le statut du nouveau genre et d’inférer la position phylogénétique des deux genres. http://www.zoobank.org/urn:lsid:zoobank.org:pub:6ED4AC9E-043C-4A04-A92D-80706694300

Phylogenetic analysis and systematics of the Acrapex unicolora Hampson species complex (Lepidoptera, Noctuidae, Apameini), with the description of five new species from the Afrotropics

Ten morphologically similar species of Acrapex Hampson, 1891 (Lepidoptera, Noctuidae, Noctuinae, Apameini) from Central and Eastern Africa are reviewed, including five new species: Acrapex kafula le Ru sp. nov., A. kavumba le Ru sp. nov., A. kiakouama le Ru sp. nov., A. miscantha le Ru sp. nov. and A. simillima le Ru sp. nov. Evidence is provided to transfer the monotypic genus Poecopa Bowden, 1956 to the genus Acrapex. Host plants of five species are recorded, some of them for the first time. Acrapex kavumba sp. nov., A. miscantha sp. nov. and A. simillima sp. nov. were found on one host plant each. Acrapex mediopuncta, previously reported in West Africa from Pennisetum purpureum Schumach., Rottboellia compressa L., Setaria megaphylla (Steud) Dur. & Schinz. and Sorghum arundinaceum (Desv.) Stapf, was only found from S. megaphylla in Central Africa. Larvae of Acrapex unicolora were collected on Andropogon gayanus Kunth, Chrysopogon zizanoides (L.) Roberty, Cymbopogon schoenanthus subsp. proximus (Hochst. ex A.Rich.) Maire & Weller, Cymbopogon pospischiilii (K.Schum.) C.E.Hubb., Hyparrhenia diplandra (Hack.) Stapf and Setaria sphacelata (Schumach.) Moss. We also conducted molecular phylogenetic analyses (using maximum likelihood) and molecular species delimitation analyses on a comprehensive sample of 61 specimens belonging to eight of the studied species. Molecular phylogenetic analyses provided additional evidence of the synonymy of Acrapex and Poecopa, whereas molecular species delimitation analyses support the validity of the five newly described species and unravel another potential new species, only collected in the larval stage