30 research outputs found

    Conversion of New Zealand's 30m Telecommunication Antenna into a Radio Telescope

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    We describe our approach to the conversion of a former 100-foot (30-m) telecommunication antenna in New Zealand into a radio telescope. We provide the specifications of the Earth Station and identify the priorities for the conversion. We describe implementation of this plan with regards to mechanical and electrical components, as well as design of the telescope control system, telescope networking for VLBI, and telescope maintenance. Plans for RF, front-end and back-end developments based on radio astronomical priorities are outlined.Comment: Accepted for PASA with small modifications, 11 pages, 13 Figure

    L'adaptation des insectes aux pressions de l'homme moderne est-elle sans danger ?

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    STRASBOURG ILLKIRCH-Pharmacie (672182101) / SudocSudocFranceF

    Fabrication and space-qualifying a lightweight corrugated horn with low sidelobes for global-Earth coverage

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    Antennas operating from geostationary satellites are often required to give global-Earth coverage for telemetry and command signals as well as conventional communications traffic. As the number of satellites in geostationary orbit increases, it is important to minimize interference to neighboring satellites. This requirement means that the amount of co- and cross-polarized sidelobe power should be as small as possible. This article describes steps in fabricating and performance testing of lightweight low-sidelobe horns.7 page(s

    Profiled horns and feeds

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    33 page(s

    A High-efficiency spline-profile smooth-walled 34–38 GHz horn as an array feed for the long-focus optics of the RATAN-600 radio telescope

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    The design of a high-efficiency spline-profile smooth-walled circular horn covering the 34-38 GHz band is described. This horn is proposed for an array feed for the RATAN-600 radio telescope. Across the band the horn has a predicted aperture efficiency >96% and a cross-polarization < -23 dB.3 page(s

    Discussion concernant la lettre que Jourdan, commandant de la gendarmerie à Avignon, à écrit à Maignet, représentant du peuple dans le département de Vaucluse, dénonçant l'arrivée du représentant Pelissier de Saint-Rémy à Avignon, en annexe de la séance du 29 germinal an II (18 avril 1794)

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    Merlin de Thionville Antoine Christophe, Granet François Omer. Discussion concernant la lettre que Jourdan, commandant de la gendarmerie à Avignon, à écrit à Maignet, représentant du peuple dans le département de Vaucluse, dénonçant l'arrivée du représentant Pelissier de Saint-Rémy à Avignon, en annexe de la séance du 29 germinal an II (18 avril 1794). In: Tome LXXXIX - Du 29 germinal au 13 floréal an II (18 avril au 2 mai 1794) p. 40

    Phosphatidylinositol-dependent phospholipases C Plc2 and Plc3 of Candida albicans are dispensable for morphogenesis and host-pathogen interaction

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    International audiencePhospholipases play an important role as virulence factors in human pathogens. Candida albicans, the major fungal pathogen of humans, encodes phospholipases of type A, B, C and D. Type B Plb2 and type D Pld1 phospholipases have been shown to contribute to virulence in this organism. We analyzed, in C. albicans, PLC2 and PLC3, two highly conserved genes coding for phosphatidylinositol-dependent phospholipases C with homology to the known virulence factor PlcA in the human pathogen Listeria monocytogenes. We show that expression of PLC2 and PLC3 is upregulated under different filament-inducing conditions and in the constitutive filamentous mutant tup1Δ. In order to analyze PLC2 and PLC3 function in C. albicans, we constructed strains that carry PLC2 or PLC3 under a constitutive promoter and strains that lack all four PLC2/3 alleles. These strains were not affected in their ability to produce filaments under non-inducing conditions, nor was filamentation modified under inducing conditions, suggesting that PLC2/3 are not critical determinants of the yeast-to-hypha switch. In a cell culture model for macrophage interaction, phagocytosis of C. albicans and subsequent killing were not influenced by PLC2/3. These results demonstrate that C. albicans PLC2 and PLC3 are dispensable for virulence; moreover, they underline the sharp contrast with the function of plcA in L. monocytogenes
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