375 research outputs found

    Preliminary Considerations from the 2nd Phase of Experiments at the SIET/SWAM Facility

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    Severe accident codes study the thermo-hydraulics of the suppression chamber with a limited numbers of nodes, generally solving mass and energy equations and assuming perfect mixing conditions. In a long station black out the effect of the sparger’s design might create local phenomena (e.g. stratification, hot-spots) which are hardly predicted by the current practices, resulting in mispredictions of the containment pressure evolution. In order to understand the effect of the sparger geometry, steam mass flux, water sub-cooling and air concentration the SWAM facility (Steam Water Air Mixing) at the SIET laboratory was employed performing around twenty different experiments, in conditions close to what is expected during the Fukushima Daiichi accident. The test facility (poll and pipes) is built with polycarbonate (transparent material) to ease the acquisition of the standard and high-speed cameras. Vertically distributed thermocouples and high-frequency pressure measurements are employed to obtain quantitative values for phenomena investigation and future CFD validations. It was shown that experiments with pure steam and relatively large diameter holes induce chugging that enhances mixing in the pool. Once chugging ceases, because of the reduced sub-cooling, a hot water layer is created in the upper part of the pool. The presence of air in the pipe induces large stratification from the condition of large subcooling because of the limited mixing introduced in the region below the pipe mouth

    Bulk and surface-sensitive high-resolution photoemission study of Mott-Hubbard systems SrVO3_3 and CaVO3_3

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    We study the electronic structure of Mott-Hubbard systems SrVO3_{3} and CaVO3_3 with bulk and surface-sensitive high-resolution photoemission spectroscopy (PES), using a VUV laser, synchrotron radiation and a discharge lamp (hνh\nu = 7 - 21 eV). A systematic suppression of the density of states (DOS) within \sim 0.2 eV of the Fermi level (EFE_F) is found on decreasing photon energy i.e. on increasing bulk sensitivity. The coherent band in SrVO3_{3} and CaVO3_3 is shown to consist of surface and bulk derived features, separated in energy. The stronger distortion on surface of CaVO3_{3} compared to SrVO3_{3} leads to higher surface metallicity in the coherent DOS at EFE_F, consistent with recent theory.Comment: 4 pages 5 figures (including 2 auxiliary figures); A complete analysis of the spectra based on the surface and bulk analysis shows in auxiliary figures Fig. A1 and A

    Gender differences in diabetes self-care in adults with type 1 diabetes: Findings from the T1D Exchange clinic registry

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    Aims To evaluate gender differences in diabetes self-care components including glycemic, blood pressure and lipid control, utilization of diabetes technologies and acute diabetes complications in adults with type 1 diabetes. Methods A total of 9,481 participants >18 years were included in the analysis, 53% were female. Variables of interest included glycemic control measured by HbA1c, systolic/diastolic blood pressures, presence of dyslipidemia, insulin delivery modality, and rates of acute complications. Results Glycemic control was similar in women and men (mean HbA1c in both groups: 8.1% ± 1.6% (64 ± 16 mmol/mol), (p = 0.54). More women used insulin pump therapy (66% vs. 59%, p < 0.001) but use of sensor technology was similar (p < = 0.42). Women had higher rates of diabetic ketoacidosis (DKA) (5% vs. 3%, p < 0.001) and eating disorders (1.7% vs. 0.1%, p < 0.001). Severe hypoglycemia rates were not different between men and women (p = 0.42). Smoking (6% vs 4%, p < 0.001), systolic (125 ± 14.2 vs. 121 ± 14.4, p < 0.001) and diastolic blood pressure (73.3 ± 9.5 vs. 72.2 ± 9.3, p < 0.001) and rate of dyslipidemia (28% vs. 23%, p < 0.001) were higher in men. Conclusion While glycemic control in type 1 diabetes was similar regardless of gender, rates of DKA and eating disorders were higher in women while rates of smoking, hypertension and dyslipidemia were higher in men

    Osteoblasts induce prostate cancer proliferation and PSA expression through interleukin-6-mediated activation of the androgen receptor

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    Prostate cancer (CaP) metastases selectively develop in bone as opposed to other sites through unknown mechanisms. Interleukin-6 (IL-6) is considered to contribute to CaP progression and is produced at high levels in osteoblasts. We hypothesized that osteoblast-derived IL-6 in the bone microenvironment contributes to the fertile soil for CaP growth. Accordingly, human CaP cells, LNCaP, C4-2B and VCaP, were treated with conditioned medium (CM) collected from human osteoblast-like HOBIT cells grown in androgen-depleted medium. We found that CM induced proliferation, prostate-specific antigen (PSA) protein and mRNA expression in a dose-dependent manner in these cell lines as determined by ELISA and real-time PCR, respectively. CM also activated the PSA promoter in these cells. Both HOBIT and primary osteoblast (POB) cells produced high levels of IL-6 measured by bioassay. LNCaP, C4-2B and VCaP cells expressed IL-6, but at much lower levels then the HOBIT and POB and they also expressed the IL-6 receptor mRNA, indicating they can respond to IL-6. Anti-IL-6 antibody added to HOBIT or POB CM dose-dependently inhibited the CM-induced cell proliferation and PSA expression in these CaP cell lines. HOBIT CM induced nuclear translocation of the AR and this was inhibited by anti-IL-6 antibody. Additionally, the antiandrogen bicalutamide inhibited HOBIT CM-induced cell proliferation. These results demonstrate that osteoblasts promote CaP growth through IL-6-mediated activation of the AR. Furthermore, these data underscore the importance of cross-talk between tumor and the bone microenvironment in the development of CaP bone metastases.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/42590/1/10585_2005_Article_56.pd

    Effect of Pictorial Depth Cues, Binocular Disparity Cues and Motion Parallax Depth Cues on Lightness Perception in Three-Dimensional Virtual Scenes

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    Surface lightness perception is affected by scene interpretation. There is some experimental evidence that perceived lightness under bi-ocular viewing conditions is different from perceived lightness in actual scenes but there are also reports that viewing conditions have little or no effect on perceived color. We investigated how mixes of depth cues affect perception of lightness in three-dimensional rendered scenes containing strong gradients of illumination in depth.Observers viewed a virtual room (4 m width x 5 m height x 17.5 m depth) with checkerboard walls and floor. In four conditions, the room was presented with or without binocular disparity (BD) depth cues and with or without motion parallax (MP) depth cues. In all conditions, observers were asked to adjust the luminance of a comparison surface to match the lightness of test surfaces placed at seven different depths (8.5-17.5 m) in the scene. We estimated lightness versus depth profiles in all four depth cue conditions. Even when observers had only pictorial depth cues (no MP, no BD), they partially but significantly discounted the illumination gradient in judging lightness. Adding either MP or BD led to significantly greater discounting and both cues together produced the greatest discounting. The effects of MP and BD were approximately additive. BD had greater influence at near distances than far.These results suggest the surface lightness perception is modulated by three-dimensional perception/interpretation using pictorial, binocular-disparity, and motion-parallax cues additively. We propose a two-stage (2D and 3D) processing model for lightness perception

    Comparative evaluation of INNO-LiPA HBV assay, direct DNA sequencing and subtractive PCR-RFLP for genotyping of clinical HBV isolates

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    Genotypes (A to H) of hepatitis B virus (HBV) influence liver disease progression and response to antiviral therapy in HBV-infected patients. Several methods have been developed for rapid genotyping of HBV strains. However, some of these methods may not be suitable for developing countries. The performance of INNO-LiPA HBV Genotyping assay (LiPA), direct DNA sequencing and subtractive PCR-RFLP of genotype-specific HBV genome regions were evaluated for accurately determining the HBV genotypes by analyzing sera (n = 80) samples from chronic HBV patients. Both, LiPA and DNA sequencing identified 63, 4 and 13 HBV strains as belonging to genotype D, genotype A and mixed genotype A and D, respectively. On the contrary, the PCR-RFLP-based method correctly identified all 4 genotype A but only 56 of 63 genotype D strains. Seven genotype D strains yielded indeterminate results. DNA sequence comparisons showed that a single nucleotide change in the target region generated an additional restriction site for Nla IV that compromised the accuracy of this method. Furthermore, all the mixed genotype A and D strains were identified only as genotype A strains. The data show that the PCR-RFLP-based method incorrectly identified some genotype D strains and failed to identify mixed genotype infections while LiPA and DNA sequencing yielded accurate results

    Hepatitis B Virus Genotype Study in West Africa Reveals an Expanding Clade of Subgenotype A4

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    Hepatitis B virus (HBV) classification comprises up to 10 genotypes with specific geographical distribution worldwide, further subdivided into 40 subgenotypes, which have different impacts on liver disease outcome. Though extensively studied, the classification of subgenotype A sequences remains ambiguous. This study aimed to characterize HBV isolates from West African patients and propose a more advanced classification of subgenotype A. Fourteen HBV full-length genome sequences isolated from patients from The Gambia and Senegal were obtained and phylogenetically analyzed. Phylogenetic analysis of HBV genotype A sequences isolated from Senegalese and Gambian patients exhibited separate clusters from the other known and confirmed subgenotypes A (A1, A2, A6). Most of the sequences (10/14) clustered with an isolate from Cuba, reported as subgenotype A4 (supported by maximal bootstrap value). Four isolates from The Gambia and Senegal clustered separately from all other subgenotypes and samples sequenced in the study. Three of which from The Gambia, designated as an expanding clade of subgenotype A4, exhibited a mean inter-subgenotypic nucleotide divergence over the entire genome sequence higher than 4% in comparison with the other subgenotypes and the other isolates sequenced in the study, except with subgenotype A4 isolates (3.9%), and this was supported by a maximal bootstrap value. The last one from Senegal seemed to be an expanding subgenotype close to the new clade of A4. Amino acid analysis unveiled a novel motif specific to these isolates. This study revealed an expanding evolution of HBV subgenotype A and novel amino acid motifs. It also highlighted the need for a consensus regarding the analysis and classification of HBV sequence
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