Linear polarization of galactic center in near infrared

Copyright European Southern ObservatoryPeer reviewe

Velocity-space sensitivity of the time-of-flight neutron spectrometer at JET

The velocity-space sensitivities of fast-ion diagnostics are often described by so-called weight functions. Recently, we formulated weight functions showing the velocity-space sensitivity of the often dominant beam-target part of neutron energy spectra. These weight functions for neutron emission spectrometry (NES) are independent of the particular NES diagnostic. Here we apply these NES weight functions to the time-of-flight spectrometer TOFOR at JET. By taking the instrumental response function of TOFOR into account, we calculate time-of-flight NES weight functions that enable us to directly determine the velocity-space sensitivity of a given part of a measured time-of-flight spectrum from TOFOR

On the mechanisms governing gas penetration into a tokamak plasma during a massive gas injection

A new 1D radial fluid code, IMAGINE, is used to simulate the penetration of gas into a tokamak plasma during a massive gas injection (MGI). The main result is that the gas is in general strongly braked as it reaches the plasma, due to mechanisms related to charge exchange and (to a smaller extent) recombination. As a result, only a fraction of the gas penetrates into the plasma. Also, a shock wave is created in the gas which propagates away from the plasma, braking and compressing the incoming gas. Simulation results are quantitatively consistent, at least in terms of orders of magnitude, with experimental data for a D 2 MGI into a JET Ohmic plasma. Simulations of MGI into the background plasma surrounding a runaway electron beam show that if the background electron density is too high, the gas may not penetrate, suggesting a possible explanation for the recent results of Reux et al in JET (2015 Nucl. Fusion 55 093013)

Relationship of edge localized mode burst times with divertor flux loop signal phase in JET

A phase relationship is identified between sequential edge localized modes (ELMs) occurrence times in a set of H-mode tokamak plasmas to the voltage measured in full flux azimuthal loops in the divertor region. We focus on plasmas in the Joint European Torus where a steady H-mode is sustained over several seconds, during which ELMs are observed in the Be II emission at the divertor. The ELMs analysed arise from intrinsic ELMing, in that there is no deliberate intent to control the ELMing process by external means. We use ELM timings derived from the Be II signal to perform direct time domain analysis of the full flux loop VLD2 and VLD3 signals, which provide a high cadence global measurement proportional to the voltage induced by changes in poloidal magnetic flux. Specifically, we examine how the time interval between pairs of successive ELMs is linked to the time-evolving phase of the full flux loop signals. Each ELM produces a clear early pulse in the full flux loop signals, whose peak time is used to condition our analysis. The arrival time of the following ELM, relative to this pulse, is found to fall into one of two categories: (i) prompt ELMs, which are directly paced by the initial response seen in the flux loop signals; and (ii) all other ELMs, which occur after the initial response of the full flux loop signals has decayed in amplitude. The times at which ELMs in category (ii) occur, relative to the first ELM of the pair, are clustered at times when the instantaneous phase of the full flux loop signal is close to its value at the time of the first ELM

Linear polarization measurements of Omicron-Sco in near infrared

Copyright Royal Astronomical Society [Full text of this article is not available in the UHRA]Peer reviewe

Detection of a bright ridge in the 2.2 MU-M emission of M82

Original article can be found via: http://cdsads.u-strasbg.fr/ Copyright Royal Astronomical Society [Full text of this article is not available in the UHRA]Photometric scans through the central region of M82 with a resolution of 6 arcsec reveal that the 2.2-micron emission source has a compact ridge structure which is approximately aligned + or - 10 deg with the major axis of the galaxy. The source has an integrated K magnitude of 6.5 and dimensions of 300 x 75 pc, corresponding to 20 x 5 arcsec on the sky. The 2.2-micron ridge embraces the bright visible knots A and E and lies close to the center of the 10-micron emission region and the subarcsecond radio source.Peer reviewe

The variable infrared source near HH100

Original article can be found via: http://cdsads.u-strasbg.fr/ Copyright Royal Astronomical Society [Full text of this article is not available in the UHRA]Photometric observations are presented which confirm the high variability, of up to 2.5 mag at K, of the IR source associated with the Herbig-Haro object HH100, and it is suggested that such a large variation must be a consequence of either (1) dramatic variations in the extinction of the source, due to the motions of a patchy circumstellar dust shell, or (2) fluctuations in the temperature of the underlying protostar. It is found that a two-component model of the source, comprising a hot star and an approximately 800 K dust shell, is required in order to account for the observations in terms of extinction changes alone. While distinguishing between the two interpretations is not possible on the basis of present data, the complications introduced by the extinction hypothesis point to intrinsic source variations.Peer reviewe

RNAi is antagonized by A→I hyper-editing

RNA interference (RNAi) and adenosine to inosine conversion are both mechanisms that respond to double-stranded RNA (dsRNA) and have been suggested to have antiviral roles. RNAi involves processing of dsRNA to short interfering RNAs (siRNAs), which subsequently mediate degradation of the cognate mRNAs. Deamination of adenosines changes the coding capacity of the RNA, as inosine is decoded as guanosine, and alters the structure because A–U base pairs are replaced by I•U wobble pairs. Here we show that RNAi is inhibited if the triggering dsRNA is first deaminated by ADAR2. Moreover, we show that production of siRNAs is progressively inhibited with increasing deamination and that this is sufficient to explain the inhibition of RNAi upon hyper-editing of dsRNAs