2,703 research outputs found

    Angiogenesis and apatinib: a new hope for patients with advanced gastric cancer?

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    Amgen; Pierre Fabreinfo:eu-repo/semantics/publishedVersio

    Quantum systems in weak gravitational fields

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    Fully covariant wave equations predict the existence of a class of inertial-gravitational effects that can be tested experimentally. In these equations inertia and gravity appear as external classical fields, but, by conforming to general relativity, provide very valuable information on how Einstein's views carry through in the world of the quantum.Comment: 22 pages. To be published in Proceedings of the 17th Course of the International School of Cosmology and Gravitation "Advances in the interplay between quantum and gravity physics" edited by V. De Sabbata and A. Zheltukhin, Kluwer Academic Publishers, Dordrech

    Base of the Toarcian Stage of the Lower Jurassic defined by the Global Boundary Stratotype Section and Point (GSSP) at the Peniche section (Portugal)

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    This is the final version of the article. Available from the publisher via the DOI in this record.The Global Stratotype Section and Point (GSSP) for the base of Toarcian Stage, Lower Jurassic, is placed at the base of micritic limestone bed 15e at Ponta do Trovão (Peniche, Lusitanian Basin, Portugal; coordinates: 39°22'15''N, 9°23'07''W), 80km north of Lisbon, and coincides with the mass occurrence of the ammonite Dactylioceras (Eodactylites). The Pliensbachian/ Toarcian boundary (PLB/TOA) is contained in a continuous section forming over 450m of carbonate-rich sediments. Tectonics, syn-sedimentary disturbance, metamorphism or significant diagenesis do not significantly affect this area. At the PLB/TOA, no vertical facies changes, stratigraphical gaps or hiatuses have been recorded. The base of the Toarcian Stage is marked in the bed 15e by the first occurrence of D. (E.) simplex, co-occurring with D. (E.) pseudocommune and D. (E.) polymorphum. The ammonite association of D. (Eodactylites) ssp. and other species e.g. Protogrammoceras (Paltarpites) cf. paltum, Lioceratoides aff. ballinense and Tiltoniceras aff. capillatum is particularly significant for the boundary definition and correlation with sections in different basins. Ammonites of the PLB/ TOA are taxa characteristic of both the Mediterranean and Northwest European provinces that allow reliable, global correlations. The PLB/TOA is also characterized by other biostratigraphical markers (brachiopods, calcareous nannofossils, ostracods and benthic foraminifers) and by high-resolution stable carbon and oxygen isotopes, and 87Sr/86Sr ratios that show distinctive changes just above the PLB/TOA, thus providing additional, powerful tools for global correlations. The PBL-TOA lies at the end of a second (and third) order cycle of sea-level change, and the top of bed 15e is interpreted as a sequence boundary. Cyclostratigraphy analysis is available for the Lower Toarcian of Ponta do Trovão. Detailed correlations with the Almonacid de la Cuba section (Iberian Range, Spain) provide complementary data of the ammonite succession in the Northwest European Hawskerense and Paltum Subzones, and magnetostratigraphical data that allow supraregional correlations. The proposal was voted on by the Toarcian Working Group in June, 2012, and by the International Subcommission on Jurassic Stratigraphy in September, 2012, approved by the ICS in November, 2014, and ratified by the IUGS in December, 2014. With this Toarcian GSSP, all international stages of the Lower Jurassic have been officially defined.Several scientists have been members of the Toarcian Working Group. We would like to acknowledge all of them. We are also grateful to the ISJS and ICS members who have made valuable comments on a previous version of this manuscript. We warmly thank Marc Philippe for his help with the literature on Pliensbachian/Toarcian continental successions. We warmly thank Christian Meister and Jim Ogg for their helpful review. Constructive remarks by Jim Ogg on an early version of the paper were greatly appreciated. We also acknowledge the precious help of David Besson for providing the ammonite specimens from the Mouterde collection (Musée des Confluences, Lyon). Ammonite photographs were taken by Emmanuel Robert (Collections de Géologie de Lyon). This paper is dedicated to the memory of Abbé René Mouterde and Serge Elmi, who died in 2007 after having been for years the main supporters of the Peniche section as GSSP of Toarcian Stage. Calcareous nannofossil slides are curated at the Collections de Géologie de Lyon (No. FSL 766535-766617). This work has been supported by the BIOSCALES Project (POCTI/ 36438/PAL/2000), coordinated by the Universidade NOVA de Lisboa; R. B. Rocha thanks the support of A. F. Soares, J. C. Kullberg, P. S. Caetano and P. H. Verdial. Financial support was provided to L. V. Duarte, S. Pinto and M. C. Cabral by Projects PDCTE/CTA/44907/2002 and PTDC/CTE-GIX/098968/2008

    CMB Telescopes and Optical Systems

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    The cosmic microwave background radiation (CMB) is now firmly established as a fundamental and essential probe of the geometry, constituents, and birth of the Universe. The CMB is a potent observable because it can be measured with precision and accuracy. Just as importantly, theoretical models of the Universe can predict the characteristics of the CMB to high accuracy, and those predictions can be directly compared to observations. There are multiple aspects associated with making a precise measurement. In this review, we focus on optical components for the instrumentation used to measure the CMB polarization and temperature anisotropy. We begin with an overview of general considerations for CMB observations and discuss common concepts used in the community. We next consider a variety of alternatives available for a designer of a CMB telescope. Our discussion is guided by the ground and balloon-based instruments that have been implemented over the years. In the same vein, we compare the arc-minute resolution Atacama Cosmology Telescope (ACT) and the South Pole Telescope (SPT). CMB interferometers are presented briefly. We conclude with a comparison of the four CMB satellites, Relikt, COBE, WMAP, and Planck, to demonstrate a remarkable evolution in design, sensitivity, resolution, and complexity over the past thirty years.Comment: To appear in: Planets, Stars and Stellar Systems (PSSS), Volume 1: Telescopes and Instrumentatio

    Expanding the knowledge about Leishmania species in wild mammals and dogs in the Brazilian savannah

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    Background: Wild, synanthropic and domestic mammals act as hosts and/or reservoirs of several Leishmania spp. Studies on possible reservoirs of Leishmania in different areas are fundamental to understand host-parasite interactions and develop strategies for the surveillance and control of leishmaniasis. In the present study, we evaluated the Leishmania spp. occurrence in mammals in two conservation units and their surroundings in Brasília, Federal District (FD), Brazil. Methods: Small mammals were captured in Brasília National Park (BNP) and Contagem Biological Reserve (CBR) and dogs were sampled in residential areas in their vicinity. Skin and blood samples were evaluated by PCR using different molecular markers (D7 24Sα rRNA and rDNA ITS1). Leishmania species were identified by sequencing of PCR products. Dog blood samples were subjected to the rapid immunochromatographic test (DPP) for detection of anti-Leishmania infantum antibodies. Results: 179 wild mammals were studied and 20.1% had Leishmania DNA successfully detected in at least one sample. Six mammal species were considered infected: Clyomys laticeps, Necromys lasiurus, Nectomys rattus, Rhipidomys macrurus, Didelphis albiventris and Gracilinanus agilis. No significant difference, comparing the proportion of individuals with Leishmania spp., was observed between the sampled areas and wild mammal species. Most of the positive samples were collected from the rodent N. lasiurus, infected by L. amazonensis or L. braziliensis. Moreover, infections by Trypanosoma spp. were detected in N. lasiurus and G. agilis. All 19 dog samples were positive by DPP; however, only three (15.8%) were confirmed by PCR assays. DNA sequences of ITS1 dog amplicons showed 100% identity with L. infantum sequence. Conclusions: The results suggest the participation of six species of wild mammals in the enzootic transmission of Leishmania spp. in FD. This is the first report of L. amazonensis in N. lasiurus
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