1,054 research outputs found

    Evidence for a circumplanetary disk around protoplanet PDS 70 b

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    We present the first observational evidence for a circumplanetary disk around the protoplanet PDS~70~b, based on a new spectrum in the KK band acquired with VLT/SINFONI. We tested three hypotheses to explain the spectrum: Atmospheric emission from the planet with either (1) a single value of extinction or (2) variable extinction, and (3) a combined atmospheric and circumplanetary disk model. Goodness-of-fit indicators favour the third option, suggesting circumplanetary material contributing excess thermal emission --- most prominent at λ2.3μ\lambda \gtrsim 2.3 \mum. Inferred accretion rates (107.8\sim 10^{-7.8}--107.3MJ10^{-7.3} M_J yr1^{-1}) are compatible with observational constraints based on the Hα\alpha and Brγ\gamma lines. For the planet, we derive an effective temperature of 1500--1600 K, surface gravity log(g)4.0\log(g)\sim 4.0, radius 1.6RJ\sim 1.6 R_J, mass 10MJ\sim 10 M_J, and possible thick clouds. Models with variable extinction lead to slightly worse fits. However, the amplitude (ΔAV3\Delta A_V \gtrsim 3mag) and timescale of variation (\lesssim~years) required for the extinction would also suggest circumplanetary material.Comment: 8 pages, 2 figures, 1 table. This is a pre-copyedited, author-produced PDF of an article accepted for publication in ApJL on 2019 May 1

    Double-Stranded RNA Technology to Control Insect Pests: Current Status and Challenges

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    Exploiting the RNA interference (RNAi) gene mechanism to silence essential genes in pest insects, leading to toxic effects, has surfaced as a promising new control strategy in the past decade. While the first commercial RNAi-based products are currently coming to market, the application against a wide range of insect species is still hindered by a number of challenges. In this review, we discuss the current status of these RNAi- based products and the different delivery strategies by which insects can be targeted by the RNAi-triggering double-stranded RNA (dsRNA) molecules. Furthermore, this review also addresses a number of physiological and cellular barriers, which can lead to decreased RNAi efficacy in insects. Finally, novel non-transgenic delivery technologies, such as polymer or liposomic nanoparticles, peptide-based delivery vehicles and viral- like particles, are also discussed, as these could overcome these barriers and lead to effective RNAi-based pest control

    Double-stranded RNA technology to control insect pests : current status and challenges

    Get PDF
    Exploiting the RNA interference (RNAi) gene mechanism to silence essential genes in pest insects, leading to toxic effects, has surfaced as a promising new control strategy in the past decade. While the first commercial RNAi-based products are currently coming to market, the application against a wide range of insect species is still hindered by a number of challenges. In this review, we discuss the current status of these RNAi-based products and the different delivery strategies by which insects can be targeted by the RNAi-triggering double-stranded RNA (dsRNA) molecules. Furthermore, this review also addresses a number of physiological and cellular barriers, which can lead to decreased RNAi efficacy in insects. Finally, novel non-transgenic delivery technologies, such as polymer or liposomic nanoparticles, peptide-based delivery vehicles and viral-like particles, are also discussed, as these could overcome these barriers and lead to effective RNAi-based pest control
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