206 research outputs found
Resumo da história literária de Portugal seguido do resumo da história literária do Brasil
Historia de Portugal
Las h. de grab. calc. :"Lemaitre direxit "; retr. de personajes hitĂłricos portugueses y monumentos de Portugal
Looking for the vector of the latest discovered geminivirus genus, Capulavirus. [P.48]
Viral metagenomics studies based on virion-associated nucleic acid extraction, sequence-independent amplification and next generation sequencing proved to be effective for discovering three highly divergent geminiviruses in South Africa, France and Finland. Although these geminiviral sequences were isolated from different continents, hemispheres and plant families, including Euphorbia caput-medusae (Euphorbiaceae), Medicago sativa (Fabaceae) and Plantago lanceolata (Plantaginaceae), they were clustered in the same phylogenetic group and were highly divergent from all the sequences classified in the seven established geminivirus genera. Based on sequence relatedness and genome organization, these new highly divergent geminivirus species were provisionally classified in a new geminivirus genus, tentatively named "Capulavirus". To estimate the epidemiological potential of these new geminiviruses but also to confirm their classification according to the criteria defined by the International Committee on Taxonomy of Viruses, including insect vector and host range, further studies were done with two capulaviruses available in our laboratory: Euphorbia caput medusae latent virus (EcmLV) from South Africa (Bernardo et al. 2013) and a capulavirus isolated from alfalfa in France provisionally named Alfalfa leaf curl virus (ALCV) according to the symptoms observed on infected plants. ALCV may cause yield losses because the infected plants exhibited stunting and distorted growth. ALCV was detected in Camargue, Provence Alpes Côte d'Azur, Languedoc Roussillon and Midi-Pyrénées. An infectious clone of EcmLV was prepared and used to determine the host range of EcmLV and test various phloem feeding insects reared in our laboratory, for vector transmission. Potentially infectious clones are presently prepared for ALCV for similar tests. In the meantime, a naturally infected alfalfa plant was transferred to a growth chamber and used as source plant for vector transmission. Potential vectors were also collected from infected alfalfa fields for testing ALCV transmission to alfalfa seedlings prepared in insect proof conditions. (Résumé d'auteur
Attractivité et performance de différents pièges utilisés pour la capture des Apoïdea à Kisangani, RD Congo
The study aimed to evaluate used traps performance on attractiveness and captured ApoĂŻdea in some pepper cropping systems in studied area. Some traps were established (sweep net, triplet of yellow, white and blue cups) in Kisangani and surrounding. Three treatments were used per site: T0: 0.5 ha of area not yet cultivated (control), T1: 0.5 ha of pepper, T2: 0.5 ha of mixing pepper-maize-cassava. Observed results showed that in Kisangani and its surrounding area, the yellow cups were the most attracted traps compared to white and blue cups in term of number of individual trapped.
Keys words: Attractiveness, performance, traps, ApoïdeaLe but visé dans cette étude est d’évaluer la performance des pièges utilisés sur l’attractivité et la capture des Apoïdea dans quelques systèmes culturaux du piment dans les sites d’essai. Pour y arriver quelques pièges ont été installés (filet fauchoire et triplet de coupelles jaunes, blanches et bleues) à Kisangani et son environ. Trois traitements ont été utilisés par site : T0 : 0,5 ha du milieu non cultivé (le témoin), T1 : 0,5 ha du piment, T2 : 0,5 ha de l’association des cultures piment-maïs-manioc. Au regard des résultats obtenus, il ressort qu’à Kisangani et son environ ce sont les coupelles jaunes qui ont été plus attractives que les blanches et les bleues en terme d’individus capturés.
Mots clé : Attractivité, performance, pièges, Apoïde
Metagenomic-based screening and molecular characterization of cowpea-infecting viruses in Burkina Faso
Cowpea, ( Vigna unguiculata L. (Walp)) is an annual tropical grain legume. Often referred to as "poor man's meat", cowpea is one of the most important subsistence legumes cultivated in West Africa due to the high protein content of its seeds. However, African cowpea production can be seriously constrained by viral diseases that reduce yields. While twelve cowpea-infecting viruses have been reported from Africa, only three of these have so-far been reported from Burkina Faso. Here we use a virion-associated nucleic acids (VANA)-based metagenomics method to screen for the presence of cowpea viruses from plants collected from the three agro-climatic zones of Burkina Faso. Besides the three cowpea-infecting virus species which have previously been reported from Burkina Faso (Cowpea aphid borne mosaic virus [Family Potyviridae ], the Blackeye cowpea mosaic virus--a strain of Bean common mosaic virus--[Family Potyviridae ] and Cowpea mottle virus [Family Tombusviridae ]) five additional viruses were identified: Southern cowpea mosaic virus (Sobemovirus genus), two previously uncharacterised polerovirus-like species (Family Luteoviridae ), a previously uncharacterised tombusvirus-like species (Family Tombusviridae ) and a previously uncharacterised mycotymovirus-like species (Family Tymoviridae ). Overall, potyviruses were the most prevalent cowpea viruses (detected in 65.5% of samples) and the Southern Sudan zone of Burkina Faso was found to harbour the greatest degrees of viral diversity and viral prevalence. Partial genome sequences of the two novel polerovirus-like and tombusvirus-like species were determined and RT-PCR primers were designed for use in Burkina Faso to routinely detect all of these cowpea-associated viruses
The Maunakea Spectroscopic Explorer Book 2018
(Abridged) This is the Maunakea Spectroscopic Explorer 2018 book. It is
intended as a concise reference guide to all aspects of the scientific and
technical design of MSE, for the international astronomy and engineering
communities, and related agencies. The current version is a status report of
MSE's science goals and their practical implementation, following the System
Conceptual Design Review, held in January 2018. MSE is a planned 10-m class,
wide-field, optical and near-infrared facility, designed to enable
transformative science, while filling a critical missing gap in the emerging
international network of large-scale astronomical facilities. MSE is completely
dedicated to multi-object spectroscopy of samples of between thousands and
millions of astrophysical objects. It will lead the world in this arena, due to
its unique design capabilities: it will boast a large (11.25 m) aperture and
wide (1.52 sq. degree) field of view; it will have the capabilities to observe
at a wide range of spectral resolutions, from R2500 to R40,000, with massive
multiplexing (4332 spectra per exposure, with all spectral resolutions
available at all times), and an on-target observing efficiency of more than
80%. MSE will unveil the composition and dynamics of the faint Universe and is
designed to excel at precision studies of faint astrophysical phenomena. It
will also provide critical follow-up for multi-wavelength imaging surveys, such
as those of the Large Synoptic Survey Telescope, Gaia, Euclid, the Wide Field
Infrared Survey Telescope, the Square Kilometre Array, and the Next Generation
Very Large Array.Comment: 5 chapters, 160 pages, 107 figure
2D layered perovskite containing functionalised benzothieno-benzothiophene molecules : formation, degradation, optical properties and photoconductivity
2D layered hybrid perovskites are currently in the spotlight for applications such as solar cells, light-emitting diodes, transistors and photodetectors. The structural freedom of 2D layered perovskites allows for the incorporation of organic cations that can potentially possess properties contributing to the performance of the hybrid as a whole. In this study, we incorporated a benzothieno[3,2-b]benzothiophene (BTBT) alkylammonium cation into the organic layer of a 2D layered lead iodide perovskite. The formation and degradation of this material are discussed in detail. It is shown that the use of a solvent vapour annealing method significantly enhances the absorption, emission and crystallinity of films of this 2D layered perovskite as compared to regular thermal annealing. The photoconductivity of the films was determined using time-resolved microwave conductivity (TRMC) as well as in a device. In both cases, the solvent vapour annealed films show markedly higher photoconductivity than the films obtained using the regular thermal annealing approach
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