The HST view of the innermost narrow line region

We analyze the properties of the innermost narrow line region in a sample of low-luminosity AGN. We select 33 LINERs (bona fide AGN) and Seyfert galaxies from the optical spectroscopic Palomar survey observed by HST/STIS. We find that in LINERs the [NII] and [OI] lines are broader than the [SII] line and that the [NII]/[SII] flux ratio increases when moving from ground-based to HST spectra. This effect is more pronounced considering the wings of the lines. Our interpretation is that, as a result of superior HST spatial resolution, we isolate a compact region of dense ionized gas in LINERs, located at a typical distance of about 3 pc and with a gas density of about 10$^4$-10$^5$ cm$^{-3}$, which we identify with the outer portion of the intermediate line region (ILR). Instead, we do not observe these kinds of effects in Seyferts; this may be the result of a stronger dilution from the NLR emission, since the HST slit maps a larger region in these sources. Alternatively, we argue that the innermost, higher density component of the ILR is only present in Seyferts, while it is truncated at larger radii because of the presence of the circumnuclear torus. The ILR is only visible in its entirety in LINERs because the obscuring torus is not present in these sources.Comment: 11 pages, 9 figures, A&A in pres

28 GHz NLOS Channel Measurements Revealing Low Path Loss and High Angular Spread in Container Ports

This paper presents results from a comprehensive measurement campaign conducted at 28 GHz inside a container canyon within a commercial port environment. The measurements are performed at various points inside the container canyon, considering two types of container stacking and two different Transmitter (TX) locations, using a narrowband channel sounder equipped with a rotating horn antenna. The measurements are used to evaluate the azimuthal spectrum and spatial correlation, as well as the impact of a vehicle inside a canyon on these parameters. Further, the measurement data is utilized to validate a simulation setup from which the path loss and the elevation spectrum inside the canyon is obtained. Lastly, a propagation model inside the canyon is hypothesized and shown to be consistent with the measurements. The analysis show a low path loss compared to free space, as well as a high angular spread and short spatial correlation.Comment: 10 pages, 19 figures. Submitted to Transactions on Antennas and Propagatio

ADIGE: the radioactive ion beam injector of the SPES project

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Rare mutations predisposing to familial adenomatous polyposis in Greek FAP patients

BACKGROUND: Familial Adenomatous Polyposis (FAP) is caused by germline mutations in the APC (Adenomatous Polyposis Coli) gene. The vast majority of APC mutations are point mutations or small insertions / deletions which lead to truncated protein products. Splicing mutations or gross genomic rearrangements are less common inactivating events of the APC gene. METHODS: In the current study genomic DNA or RNA from ten unrelated FAP suspected patients was examined for germline mutations in the APC gene. Family history and phenotype were used in order to select the patients. Methods used for testing were dHPLC (denaturing High Performance Liquid Chromatography), sequencing, MLPA (Multiplex Ligation – dependent Probe Amplification), Karyotyping, FISH (Fluorescence In Situ Hybridization) and RT-PCR (Reverse Transcription – Polymerase Chain Reaction). RESULTS: A 250 Kbp deletion in the APC gene starting from intron 5 and extending beyond exon 15 was identified in one patient. A substitution of the +5 conserved nucleotide at the splice donor site of intron 9 in the APC gene was shown to produce frameshift and inefficient exon skipping in a second patient. Four frameshift mutations (1577insT, 1973delAG, 3180delAAAA, 3212delA) and a nonsense mutation (C1690T) were identified in the rest of the patients. CONCLUSION: Screening for APC mutations in FAP patients should include testing for splicing defects and gross genomic alterations

Inactivation of promoter 1B of APC causes partial gene silencing: evidence for a significant role of the promoter in regulation and causative of familial adenomatous polyposis

Familial adenomatous polyposis (FAP) is caused by germline mutations in the adenomatous polyposis coli (APC) gene. Two promoters, 1A and 1B, have been recognized in APC, and 1B is thought to have a minor role in the regulation of the gene. We have identified a novel deletion encompassing half of this promoter in the largest family (Family 1) of the Swedish Polyposis Registry. The mutation leads to an imbalance in allele-specific expression of APC, and transcription from promoter 1B was highly impaired in both normal colorectal mucosa and blood from mutation carriers. To establish the significance of promoter 1B in normal colorectal mucosa (from controls), expression levels of specific transcripts from each of the promoters, 1A and 1B, were examined, and the expression from 1B was significantly higher compared with 1A. Significant amounts of transcripts generated from promoter 1B were also determined in a panel of 20 various normal tissues examined. In FAP-related tumors, the APC germline mutation is proposed to dictate the second hit. Mutations leaving two or three out of seven 20-amino-acid repeats in the central domain of APC intact seem to be required for tumorigenesis. We examined adenomas from mutation carriers in Family 1 for second hits in the entire gene without any findings, however, loss of the residual expression of the deleterious allele was observed. Three major conclusions of significant importance in relation to the function of APC can be drawn from this study; (i) germline inactivation of promoter 1B is disease causing in FAP; (ii) expression of transcripts from promoter 1B is generated at considerable higher levels compared with 1A, demonstrating a hitherto unknown importance of 1B; (iii) adenoma formation in FAP, caused by impaired function of promoter 1B, does not require homozygous inactivation of APC allowing for alternative genetic models as basis for adenoma formation

Evaluation of image quality with four positron emitters and three preclinical PET/CT systems

Background We investigated the image quality of C-11, Ga-68, F-18 and Zr-89, which have different positron fractions, physical half-lifes and positron ranges. Three small animal positron emission tomography/computed tomography (PET/CT) systems were used in the evaluation, including the Siemens Inveon, RAYCAN X5 and Molecubes beta-cube. The evaluation was performed on a single scanner level using the national electrical manufacturers association (NEMA) image quality phantom and analysis protocol. Acquisitions were performed with the standard NEMA protocol for F-18 and using a radionuclide-specific acquisition time for C-11, Ga-68 and Zr-89. Images were assessed using percent recovery coefficient (%RC), percentage standard deviation (%STD), image uniformity (%SD), spill-over ratio (SOR) and evaluation of image quantification. Results Ga-68 had the lowest %RC ( 85%) and lowest %STD for the 5 mm rod across all systems. For C-11 and Zr-89, the maximum %RC was close (> 76%) to the %RC with F-18. A larger SOR were measured in water with C-11 and Ga-68 compared to F-18 on all systems. SOR in air reflected image reconstruction and data correction performance. Large variation in image quantification was observed, with maximal errors of 22.73% (Zr-89, Inveon), 17.54% (Zr-89, RAYCAN) and - 14.87% (Ga-68, Molecubes). Conclusions The systems performed most optimal in terms of NEMA image quality parameters when using F-18, where C-11 and Zr-89 performed slightly worse than F-18. The performance was least optimal when using Ga-68, due to large positron range. The large quantification differences prompt optimization not only by terms of image quality but also quantification. Further investigation should be performed to find an appropriate calibration and harmonization protocol and the evaluation should be conducted on a multi-scanner and multi-center level