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Emission geometries, including emission region heights, beam shapes and radius-to-frequency mapping, are important clues for pulsar radiation models. Multiband radio observations reveal this valuable information. In this paper, we study two bright pulsars, PSRs B0329+54 and B1642-03, and observe them at high frequencies: 2.5, 5 and 8 GHz. The newly acquired data, together with historical archives, provide an atlas of multifrequency profiles spanning from 100 MHz to 10 GHz. We study the frequency evolution of pulse profiles as well as radiation regions using these data. First, we fit the pulse profiles with Gaussian functions to determine the phase of each component, and then we calculate the radiation altitudes of different emission components and radiation regions. We find that the inverse Compton scattering (ICS) model can reproduce the radiation geometry of these two pulsars. However, for PSR B0329+54, the radiation can be generated in either an annular gap (AG) or a core gap (CG), while the radiation of PSR B1642-03 can only be generated in a CG. This difference is caused by the inclination angle and the impact angle of these two pulsars. The relationship between the beaming angle (the angle between the radiation direction and the magnetic axis) and the radiation altitude versus frequency is also presented by modelling the beam–frequency evolution in the ICS model. The multiband pulse profiles of these two pulsars can be described well by the ICS model combined with the CG and AG. [ABSTRACT FROM AUTHOR]

We report the results of the OH maser observation towards the water fountain source IRAS 18286–0959 using the newly built Shanghai Tianma 65-m Radio Telescope. We observed the three OH ground state transition lines at frequencies of 1612, 1665 and 1667 MHz. Comparing with the spectra of previous observations, we find new maser spectral components at velocity channels largely shifted from the systemic velocity: the velocity offsets of the newly found components lie in the range 20-40 km s-1 with respect to the systemic velocity. Besides maser variability, another possible interpretation for the newly detected maser features is that part of the molecular gas in the circumstellar envelope is accelerated. The acceleration is probably caused by the passage of a high-velocity molecular jet, which has been detected in previous Very Long Baseline Interferometry observations in the H2O maser line. [ABSTRACT FROM AUTHOR]

Recently, we have demonstrated that F3/contactin and NB-3 are trans-acting extracellular ligands of Notch that promote differentiation of neural stem cells and oligodendrocyte precursor cells into mature oligodendrocytes (OLs). Here, we demonstrate that human bone marrow stromal cells (hBMSCs) can be induced to differentiate into cells with myelinating glial cell characteristics in mouse retina after predifferentiation in vitro. Isolated CD90(+) hBMSCs treated with β-mercaptoethanol for 1 day and retinoic acid for 3 days in culture changed into myelinating glia-like cells (MGLCs). More cells expressed NG2, an early OL marker, after treatment, but expression of O4, a mature OL marker, was negligible. Subsequently, the population of O4(+) cells was significantly increased after the MGLCs were predifferentiated in culture in the presence of either F3/contactin or multiple factors, including forskolin, basic fibroblast growth factor, platelet-derived growth, factor, and heregulin, in vitro for another 3 days. Notably, 2 months after transplantation into mouse retina, the predifferentiated cells changed morphologically into cells resembling mature MGLCs and expressing O4 and myelin basic protein, two mature myelinating glial cell markers. The cells sent out processes to contact and wrap axons, an event that normally occurs during early stages of myelination, in the retina. The results suggest that CD90(+) hBMSCs are capable of morphological and functional differentiation into MGLCs in vivo through predifferentiation by triggering F3/Notch signaling in vitro. [ABSTRACT FROM AUTHOR]

Describes the development of a polymerase chain reaction method based on amplification of a specific DNA fragment for the identification of camel, Camelus materials. Design of a species-specific primer pair L183/H372 based no the nucleotide sequence of the mitochondrial cytochrome b gene; Amplification of a pair fragment.