Convective motions and net circular polarization in sunspot penumbrae

We have employed a penumbral model, that includes the Evershed flow and convective motions inside penumbral filaments, to reproduce the azimuthal variation of the net circular polarization (NCP) in sunspot penumbrae at different heliocentric angles for two different spectral lines. The theoretical net circular polarization fits the observations as satisfactorily as penumbral models based on flux-tubes. The reason for this is that the effect of convective motions on the NCP is very small compared to the effect of the Evershed flow. In addition, the NCP generated by convective upflows cancels out the NCP generated by the downflows. We have also found that, in order to fit the observed NCP, the strength of the magnetic field inside penumbral filaments must be very close to 1000 G. In particular, field-free or weak-field filaments fail to reproduce both the correct sign of the net circular polarization, as well as its dependence on the azimuthal and heliocentric angles.Comment: Accepted for publication in the Astrophysical Journal. 10 pages, 7 figures (3 in color). Uses emulatedap

Spectrum of the Anomalous Microwave Emission in the North Celestial Pole with WMAP 7-Year data

We estimate the frequency spectrum of the diffuse anomalous microwave emission (AME) on the North Celestial Pole (NCP) region of the sky with the Correlated Component Analysis (CCA) component separation method applied to WMAP 7-yr data. The NCP is a suitable region for this analysis because the AME is weakly contaminated by synchrotron and free-free emission. By modeling the AME component as a peaked spectrum we estimate the peak frequency to be $21.7\pm0.8$\,GHz, in agreement with previous analyses which favored $\nu_{\rm p}<23$\,GHz. The ability of our method to correctly recover the position of the peak is verified through simulations. We compare the estimated AME spectrum with theoretical spinning dust models to constrain the hydrogen density $n_{\rm H}$. The best results are obtained with densities around 0.2--0.3\,cm$^{-3}$, typical of warm ionised medium (WIM) to warm neutral medium (WNM) conditions. The degeneracy with the gas temperature prevents an accurate determination of $n_{\rm H}$, especially for low hydrogen ionization fractions, where densities of a few cm$^{-3}$ are also allowed.Comment: 13 pages, 6 figures, published in Advances in Astronom

Radio Sources in the NCP Region Observed with the 21 Centimeter Array

We present a catalog of 624 radio sources detected around the North Celestial Pole (NCP) with the 21 Centimeter Array (21CMA), a radio interferometer dedicated to the statistical measurement of the epoch of reionization (EoR). The data are taken from a 12 h observation made on 2013 April 13, with a frequency coverage from 75 to 175 MHz and an angular resolution of ~ 4 arcmin. The catalog includes flux densities at eight sub-bands across the 21CMA bandwidth and provides the in-band spectral indices for the detected sources. To reduce the complexity of interferometric imaging from the so-called "w" term and ionospheric effects, the present analysis are restricted to the east-west baselines within 1500 m only. The 624 radio sources are found within 5 degrees around the NCP down to ~ 0.1 Jy. Our source counts are compared, and also exhibit a good agreement, with deep low-frequency observations made recently with the GMRT and MWA. In particular, for fainter radio sources below ~ 1 Jy, we find a flattening trend of source counts towards lower frequencies. While the thermal noise (~0.4 mJy) is well controlled to below the confusion limit, the dynamical range (~10^4) and sensitivity of current 21CMA imaging is largely limited by calibration and deconvolution errors, especially the grating lobes of very bright sources, such as 3C061.1, in the NCP field which result from the regular spacings of the 21CMA. We note that particular attention should be paid to the extended sources, and their modeling and removals may constitute a large technical challenge for current EoR experiments. Our analysis may serve as a useful guide to design of next generation low-frequency interferometers like the Square Kilometre Array.Comment: 16 pages, 21 figures, 7 tables, 1 machine readable table, accepted for publication in Ap

学会抄録

<p>A. The average number of interactions decomposed by the interaction partners in 7 categories: NP, CP, MP, NCP, CMP, NCMP, and others. The full size view is shown in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0156455#pone.0156455.s003" target="_blank">S2 Fig</a>. B. The Venn diagram representing the interaction of NP with NCP. In total, 2,498 NP were analyzed. The NP with intra-interactions and interacting with NCP are shown by the two circles in the box. The intersection of two circles represents the shared interaction partners. Among these proteins, 1,250 NP neither intra-interact nor interact with NCP. C. The summary of interactions in terms of interaction partners. S symbols indicate that the interaction is rich (at least 0.6 interaction partners) between the protein (the left column) and the interaction partners (the top row), and the interaction partners are shared (at least 0.5) with the intra-interactions of partner proteins (<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0156455#pone.0156455.s010" target="_blank">S6 Table</a>). For other symbols, see the bottom of the panel.</p

Kinetic analysis of drug release from nanoparticles

PURPOSE. Comparative drug release kinetics from nanoparticles was carried out using conventional and our novel models with the aim of finding a general model applicable to multi mechanistic release. Theoretical justification for the two best general models was also provided for the first time. METHODS. Ten conventional models and three models developed in our laboratory were applied to release data of 32 drugs from 106 nanoparticle formulations collected from literature. The accuracy of the models was assessed employing mean percent error (E) of each data set, overall mean percent error (OE) and number of Es less than 10 percent. RESULTS. Among the models the novel reciprocal powered time (RPT), Weibull (W) and log-probability (LP) ones produced OE values of 6.47, 6.39 and 6.77, respectively. The OEs of other models were higher than 10%. Also the number of errors less than 10% for the models was 84.9, 80.2 and 78.3 percents of total number of data sets. CONCLUSIONS. Considering the accuracy criteria the reciprocal powered time model could be suggested as a general model for analysis of multi mechanistic drug release from nanoparticles. Also W and LP models were the closest to the suggested model RPT

A Network Congestion control Protocol (NCP)

The transmission control protocol (TCP) which is the dominant congestion control protocol at the transport layer is proved to have many performance problems with the growth of the Internet. TCP for instance results in throughput degradation for high bandwidth delay product networks and is unfair for flows with high round trip delays. There have been many patches and modifications to TCP all of which inherit the problems of TCP in spite of some performance improve- ments. On the other hand there are clean-slate design approaches of the Internet. The eXplicit Congestion control Protocol (XCP) and the Rate Control Protocol (RCP) are the prominent clean slate congestion control protocols. Nonetheless, the XCP protocol is also proved to have its own performance problems some of which are its unfairness to long flows (flows with high round trip delay), and many per-packet computations at the router. As shown in this paper RCP also makes gross approximation to its important component that it may only give the performance reports shown in the literature for specific choices of its parameter values and traffic patterns. In this paper we present a new congestion control protocol called Network congestion Control Protocol (NCP). We show that NCP can outperform both TCP, XCP and RCP in terms of among other things fairness and file download times.unpublishe

NCP activates chloroplast transcription by controlling phytochrome-dependent dual nuclear and plastidial switches.

Phytochromes initiate chloroplast biogenesis by activating genes encoding the photosynthetic apparatus, including photosynthesis-associated plastid-encoded genes (PhAPGs). PhAPGs are transcribed by a bacterial-type RNA polymerase (PEP), but how phytochromes in the nucleus activate chloroplast gene expression remains enigmatic. We report here a forward genetic screen in Arabidopsis that identified NUCLEAR CONTROL OF PEP ACTIVITY (NCP) as a necessary component of phytochrome signaling for PhAPG activation. NCP is dual-targeted to plastids and the nucleus. While nuclear NCP mediates the degradation of two repressors of chloroplast biogenesis, PIF1 and PIF3, NCP in plastids promotes the assembly of the PEP complex for PhAPG transcription. NCP and its paralog RCB are non-catalytic thioredoxin-like proteins that diverged in seed plants to adopt nonredundant functions in phytochrome signaling. These results support a model in which phytochromes control PhAPG expression through light-dependent double nuclear and plastidial switches that are linked by evolutionarily conserved and dual-localized regulatory proteins