The Masers Towards IRAS 20126+4104

We present MERLIN observations of OH, water and methanol masers towards the young high mass stellar object IRAS 20126+4104. Emission from the 1665-MHz OH, 22-GHz H_2O and 6.7-GHz CH_3OH masers is detected and all originates very close to the central source. The OH and methanol masers appear to trace part of the circumstellar disk around the central source. The positions and velocities of the OH and methanol masers are consistent with Keplerian rotation around a central mass of ~ 5 Msun. The water masers are offset from the OH and methanol masers and have significantly changed since they were last observed, but still appear to be associated to the outflow from the source. All the OH masers components are circularly polarised, in some cases reaching 100 percent while some OH components also have linear polarisation. We identify one Zeeman pair of OH masers and the splitting of this pair indicates a magnetic field of strength ~ 11 mG within ~ 0.5" (850 AU) of the central source. The OH and methanol maser emission suggest that the disk material is dense, n > 10^6 cm^-3, and warm, T > 125 K and the high abundance of methanol required by the maser emission is consistent with the evaporation of the mantles on dust grains in the disk as a result of heating or shocking of the disk materialComment: 9 pages, 7 figures and 6 table

The OH Masers Towards IRAS 19092+0841

Context. Maser emission is a strong tool for studying high mass star forming regions and their evolutionary stages. OH masers in particular can trace the circumstellar material around protostars and determine their magnetic field strengths at milliarcsecond resolution. Aims. Imaging OH maser mission towards high mass protostellar objects to determine their evolutionary stages and to locate the detected maser emission in the process of high mass star formation. Methods. In 2007, we surveyed OH maser towards 217 high mass protostellar objects to study its presence. In this paper, we present a follow up MERLIN observations of a ground state OH maser emission towards one of these objects, IRAS 19092+0841. Results. Emission from the two OH main spectral lines, 1665 and 1667 MHz, were detected close to the central object. The positions and velocities of the OH maser features have been determined. The masers are distributed over a region of ~ 500 corresponding to 22400 AU (or ~ 0.1 pc) at a distance of 4.48 kpc. The polarization properties of the OH maser features were determined as well. We identify three Zeeman pairs from which we inferred a magnetic field strength of ~ 4:4mG pointing towards the observer. Conclusions. The relatively small velocity spread and the relatively wide spacial distribution of the OH maser features support the suggestion that this object could be in an early evolutionary state before the presence of disk and/or jet/outfows.Comment: 6 pages, 2 figures and 3 table

Discovery of molecular subtypes in leiomyosarcoma through integrative molecular profiling.

Leiomyosarcoma (LMS) is a soft tissue tumor with a significant degree of morphologic and molecular heterogeneity. We used integrative molecular profiling to discover and characterize molecular subtypes of LMS. Gene expression profiling was performed on 51 LMS samples. Unsupervised clustering showed three reproducible LMS clusters. Array comparative genomic hybridization (aCGH) was performed on 20 LMS samples and showed that the molecular subtypes defined by gene expression showed distinct genomic changes. Tumors from the muscle-enriched cluster showed significantly increased copy number changes (P=0.04). A majority of the muscle-enriched cases showed loss at 16q24, which contains Fanconi anemia, complementation group A, known to have an important role in DNA repair, and loss at 1p36, which contains PRDM16, of which loss promotes muscle differentiation. Immunohistochemistry (IHC) was performed on LMS tissue microarrays (n=377) for five markers with high levels of messenger RNA in the muscle-enriched cluster (ACTG2, CASQ2, SLMAP, CFL2 and MYLK) and showed significantly correlated expression of the five proteins (all pairwise P<0.005). Expression of the five markers was associated with improved disease-specific survival in a multivariate Cox regression analysis (P<0.04). In this analysis that combined gene expression profiling, aCGH and IHC, we characterized distinct molecular LMS subtypes, provided insight into their pathogenesis, and identified prognostic biomarkers

A Survey of OH Masers Towards High Mass Protostellar Objects

We present a survey of OH maser emission towards a sample of high mass protostellar objects made using the Nancay and GBT telescopes.OH maser emission was detected towards 63 objects with 36 new detections. There are 56 star-forming regions and 7 OH/IR candidates. There is no evidence that sources with OH masers have a different range of luminosities from the non-maser sources. The results of this survey are compared with previous water and class II methanol maser observations of the same objects. Some of the detected sources are only associated with OH masers and some sources are only associated with the 1720 MHz OH maser line. The velocity range of the maser emission suggests that the water maser sources may be divided into two groups. The detection rates and velocity range of the OH and Class II methanol masers support the idea that there is a spatial association of the OH and Class II methanol masers. The sources span a wide range in R, the ratio of the methanol maser peak flux to OH 1665 MHz maser peak flux, however there are only a few sources with intermediate values of R, 8<R<32, which has characterised previous samples. Sources which have masers of any species, OH, water or methanol, have redder [100um-12um] IRAS colours than those without masers. However, there is no evidence for different maser species tracing different stages in the evolution of these young high mass sources. Previous observations which have shown that the OH maser emission from similar sources traces the circumstellar disks around the objects. This combined with the sensitivity of the OH emission to the magnetic field, make the newly detected sources interesting candidates for future follow-up at high angular resolution.Comment: Accepted for publication in A&

Intermittent maser flare around the high mass young stellar object G353.273+0.641 I: data & overview

We have performed VLBI and single-dish monitoring of 22 GHz H$_{2}$O maser emission from the high mass young stellar object G353.273+0.641 with VERA (VLBI Exploration of Radio Astrometry) and Tomakamai 11-m radio telescope. Two maser flares have been detected, separated almost two years. Frequent VLBI monitoring has revealed that these flare activities have been accompanied by structural change of the prominent shock front traced by H2O maser alignments. We have detected only blue-shifted emissions and all maser features have been distributed within very small area of 200 $\times$ 200 au$^{2}$ in spite of wide velocity range (> 100 km s$^{-1}$). The light curve shows notably intermittent variation and suggests that the H$_{2}$O masers in G353.273+0.641 are excited by episodic radio jet. The time-scale of \sim2 yr and characteristic velocity of \sim500 km s$^{-1}$ also support this interpretation. Two isolated velocity components of C50 (-53 \pm 7 km s$^{-1}$) and C70 (-73 \pm 7 km s$^{-1}$) have shown synchronised linear acceleration of the flux weighted V_{\rmn{LSR}} values (\sim-5 km s$^{-1}$ yr$^{-1}$) during the flare phase. This can be converted to the lower-limit momentum rate of 1.1 \times 10$^{-3}$ M_{\sun} km s$^{-1}$ yr$^{-1}$. Maser properties are quite similar to that of IRAS 20126+4104 especially. This corroborates the previous suggestion that G353.273+0.641 is a candidate of high mass protostellar object. The possible pole-on geometry of disc-jet system can be suitable for direct imaging of the accretion disc in this case.Comment: 13 pages, 5 figures accepted for publication in MNRA

Molecular detection of Epstein-Barr virus among Sudanese patients diagnosed with Hashimoto’s thyroiditis

Objectives: Hashimoto’s thyroiditis (HT) is the most common cause of hypothyroidism. The exact mechanism initiating the development of HT is not yet clear. This study aimed to investigate the correlation between HT and the presence of Epstein-Barr virus (EBV) in a Sudanese population. Results: EBV-LMP1 was detected in 11.1% of HT cases, which is consistent with previous studies. Studies have reported a wide range of frequencies indicating the presence of EBV in HT, and patients with autoimmune thyroiditis have increased titers of anti-EBV antibodies in their sera compared to healthy subjects. Intrathyroidal EBV-infected B cells may be responsible for the increased risk of development of B-cell lymphoma in the thyroid gland in patients with autoimmune thyroiditis. Our study suggests that regular follow-up is necessary for patients diagnosed with HT and are positive for EBV, as antiviral therapy is not applicable due to the risk of thyroid dysfunction. The study suggests an association between EBV and HT, but causation cannot be determined. The study also highlights the need for further research to determine the viral role and correlate it with the severity and progression of HT.</p

Molecular detection of Epstein-Barr virus among Sudanese patients diagnosed with Hashimoto’s thyroiditis

Objectives: Hashimoto’s thyroiditis (HT) is the most common cause of hypothyroidism. The exact mechanism initiating the development of HT is not yet clear. This study aimed to investigate the correlation between HT and the presence of Epstein-Barr virus (EBV) in a Sudanese population. Results: EBV-LMP1 was detected in 11.1% of HT cases, which is consistent with previous studies. Studies have reported a wide range of frequencies indicating the presence of EBV in HT, and patients with autoimmune thyroiditis have increased titers of anti-EBV antibodies in their sera compared to healthy subjects. Intrathyroidal EBV-infected B cells may be responsible for the increased risk of development of B-cell lymphoma in the thyroid gland in patients with autoimmune thyroiditis. Our study suggests that regular follow-up is necessary for patients diagnosed with HT and are positive for EBV, as antiviral therapy is not applicable due to the risk of thyroid dysfunction. The study suggests an association between EBV and HT, but causation cannot be determined. The study also highlights the need for further research to determine the viral role and correlate it with the severity and progression of HT.</p