Kinematics and H_2 morphology of the multipolar Post-AGB star IRAS 16594-4656

context: The spectrum of IRAS 16594-4656 shows shock excited H_2 emission and collisionally excited emission lines such as[O I],[C I],and [Fe II]. aim: The goal is to determine the location of the H_2 and [Fe II] shock emission, to determine the shock velocities,and constrain the physical properties in the shock. methods: High resolution spectra of the H_2 1-0 S(1),H_2 2-1 S(1), [Fe II], and Pa$\beta$ emission lines were obtained with the near infrared spectrograph Phoenix on Gemini South. results: The position-velocity diagrams of H_2 1-0 S(1), H_2 2-1 S(1), and [Fe II] are presented. The H_2 and [Fe II] emission is spatially extended. The collisionally excited [O I] and [C I] optical emission lines have a similar double peaked profile compared to the extracted H_2 profile and appear to be produced in the same shock. They all indicate an expansion velocity of ~8 km/s and the presence of a neutral, very high density region with $n_{\rm e}$ about 3 x 10^6 to 5 x10^7 cm$^{-3}$. The [Fe II] emission however is single peaked. It has a gaussian FWHM of 30 km/s and a total width of 62 km/s at 1% of the peak. The Pa$\beta$ profile is even wider with a gaussian FWHM of 48 km/s and a total width of 75 km/s at 1% of the peak. conclusions: The H$_2$ emission is excited in a slow 5 to 20 km/s shock into dense material at the edge of the lobes, caused by the interaction of the AGB ejecta and the post-AGB wind. The 3D representation of the H_2 data shows a hollow structure with less H_2 emission in the equatorial region. The [Fe II] emission is not present in the lobes, but originates close to the central star in fast shocks in the post-AGB wind or in a disk. The Pa$\beta$ emission also appears to originate close to the star.Comment: 11 pages and 8 figures; A&A in press; the paper includig high resolution figures can be downloaded from http://homepage.oma.be/gsteene/publications.htm

Post-main sequence evolution of A star debris discs

While the population of main sequence debris discs is well constrained, little is known about debris discs around evolved stars. This paper provides a theoretical framework considering the effects of stellar evolution on debris discs, particularly the production and loss of dust within them. Here we repeat a steady state model fit to disc evolution statistics for main sequence A stars, this time using realistic grain optical properties, then evolve that population to consider its detectability at later epochs. Our model predicts that debris discs around giant stars are harder to detect than on the main sequence because radiation pressure is more effective at removing small dust around higher luminosity stars. Just 12% of first ascent giants within 100pc are predicted to have discs detectable with Herschel at 160um. However this is subject to the uncertain effect of sublimation on the disc, which we propose can thus be constrained with such observations. Our model also finds that the rapid decline in stellar luminosity results in only very young white dwarfs having luminous discs. As such systems are on average at larger distances they are hard to detect, but we predict that the stellar parameters most likely to yield a disc detection are a white dwarf at 200pc with cooling age of 0.1Myr, in line with observations of the Helix Nebula. Our model does not predict close-in (<0.01AU) dust, as observed for some white dwarfs, however we find that stellar wind drag leaves significant mass (~10^{-2}Msolar), in bodies up to ~10m in diameter, inside the disc at the end of the AGB phase which may replenish these discs

Associations of pain intensity and pain-related disability with psychological and socio-demographic factors in patients with temporomandibular disorders:A cross-sectional study at a specialised dental clinic

The study assessed whether psychological and socio-demographic factors, including somatisation, depression, stress, anxiety, daytime sleepiness, optimism, gender and age, are associated with pain intensity and pain-related disability in patients with temporomandibular disorders (TMDs). In total, 320 TMD patients were involved in the study. The psychological status of each patient was assessed with questionnaires, including the Symptom Checklist-90 (SCL-90), Epworth Sleeping Scale (ESS), stress questionnaire and Life Orientation Test-Revised (LOT-R). TMD pain, including pain intensity and pain-related disability, was assessed with characteristic pain intensity (CPI) and disability points scales. The associations of psychological and socio-demographic factors with pain intensity and pain-related disability were assessed through logistic regression analyses. Higher pain intensity was significantly associated with more severe anxiety (P = 0·004), more severe somatisation (P < 0·001), more severe depression (P < 0·001), more severe stress (P = 0·001) and lower optimism (P = 0·025) in univariate regression analyses. However, multiple regression analysis showed that only somatisation was significantly associated with pain intensity (P < 0·001). Higher pain-related disability was significantly associated with more severe anxiety (P < 0·001), more severe somatisation (P < 0·001), more severe depression (P < 0·001), more severe stress (P < 0·001) and lower optimism (P = 0·003) in univariate regression analyses. However, multiple regression analysis showed that only depression was significantly associated with pain-related disability (P = 0·003). Among the psychological and socio-demographic factors in this study, somatisation was the best predictor of pain intensity, while depression was the best predictor of pain-related disability

Confirming the Primarily Smooth Structure of the Vega Debris Disk at Millimeter Wavelengths

Clumpy structure in the debris disk around Vega has been previously reported at millimeter wavelengths and attributed to concentrations of dust grains trapped in resonances with an unseen planet. However, recent imaging at similar wavelengths with higher sensitivity has disputed the observed structure. We present three new millimeter wavelength observations that help to resolve the puzzling and contradictory observations. We have observed the Vega system with the Submillimeter Array (SMA) at a wavelength of 880 μm and an angular resolution of 5"; with the Combined Array for Research in Millimeter-wave Astronomy (CARMA) at a wavelength of 1.3 mm and an angular resolution of 5"; and with the Green Bank Telescope (GBT) at a wavelength of 3.3 mm and angular resolution of 10". Despite high sensitivity and short baselines, we do not detect the Vega debris disk in either of the interferometric data sets (SMA and CARMA), which should be sensitive at high significance to clumpy structure based on previously reported observations. We obtain a marginal (3σ) detection of disk emission in the GBT data; the spatial distribution of the emission is not well constrained.We analyze the observations in the context of several different models, demonstrating that the observations are consistent with a smooth, broad, axisymmetric disk with inner radius 20–100 AU and width ≾50 AU. The interferometric data require that at least half of the 860 μm emission detected by previous single-dish observations with the James Clerk Maxwell Telescope be distributed axisymmetrically, ruling out strong contributions from flux concentrations on spatial scales of ≾100 AU. These observations support recent results from the Plateau de Bure Interferometer indicating that previous detections of clumpy structure in the Vega debris disk were spurious

Tensor Operators for Uh(sl(2))

Tensor operators for the Jordanian quantum algebra Uh(sl(2)) are considered. Some explicit examples of them, which are obtained in the boson or fermion realization, are given and their properties are studied. It is also shown that the Wigner-Eckart's theorem can be extended to Uh(sl(2)).Comment: 11pages, LaTeX, to be published in J. Phys.

Cabozantinib in hepatocellular carcinoma: results of a phase 2 placebo-controlled randomized discontinuation study.

BackgroundCabozantinib, an orally bioavailable inhibitor of tyrosine kinases including MET, AXL, and VEGF receptors, was assessed in patients with hepatocellular carcinoma (HCC) as part of a phase 2 randomized discontinuation trial with nine tumor-type cohorts.Patients and methodsEligible patients had Child-Pugh A liver function and ≤1 prior systemic anticancer regimen, completed ≥4 weeks before study entry. The cabozantinib starting dose was 100 mg daily. After an initial 12-week cabozantinib treatment period, patients with stable disease (SD) per Response Evaluation Criteria in Solid Tumors (RECIST) version 1.0 were randomized to cabozantinib or placebo. The primary endpoint of the lead-in stage was objective response rate (ORR) at week 12, and the primary endpoint of the randomized stage was progression-free survival (PFS).ResultsAmong the 41 HCC patients enrolled, the week 12 ORR was 5%, with 2 patients achieving a confirmed partial response (PR). The week 12 disease control rate (PR or SD) was 66% (Asian subgroup: 73%). Of patients with ≥1 post-baseline scan, 78% had tumor regression, with no apparent relationship to prior sorafenib therapy. Alpha-fetoprotein (AFP) response (&gt;50% reduction from baseline) occurred in 9 of the 26 (35%) patients with elevated baseline AFP and ≥1 post-baseline measurement. Twenty-two patients with SD at week 12 were randomized. Median PFS after randomization was 2.5 months with cabozantinib and 1.4 months with placebo, although this difference was not statistically significant. Median PFS and overall survival from Day 1 in all patients were 5.2 and 11.5 months, respectively. The most common grade 3/4 adverse events, regardless of attribution, were diarrhea (20%), hand-foot syndrome (15%), and thrombocytopenia (15%). Dose reductions were utilized in 59% of patients.ConclusionsCabozantinib has clinical activity in HCC patients, including objective tumor responses, disease stabilization, and reductions in AFP. Adverse events were managed with dose reductions.Trial registration numberNCT00940225

Electric fields and valence band offsets at strained [111] heterojunctions

[111] ordered common atom strained layer superlattices (in particular the common anion GaSb/InSb system and the common cation InAs/InSb system) are investigated using the ab initio full potential linearized augmented plane wave (FLAPW) method. We have focused our attention on the potential line-up at the two sides of the homopolar isovalent heterojunctions considered, and in particular on its dependence on the strain conditions and on the strain induced electric fields. We propose a procedure to locate the interface plane where the band alignment could be evaluated; furthermore, we suggest that the polarization charges, due to piezoelectric effects, are approximately confined to a narrow region close to the interface and do not affect the potential discontinuity. We find that the interface contribution to the valence band offset is substantially unaffected by strain conditions, whereas the total band line-up is highly tunable, as a function of the strain conditions. Finally, we compare our results with those obtained for [001] heterojunctions.Comment: 18 pages, Latex-file, to appear in Phys.Rev.

Peribiliary glands are key in regeneration of the human biliary epithelium after severe bile duct injury

Peribiliary glands (PBG) are a source of stem/progenitor cells organized in a cellular network encircling large bile ducts. Severe cholangiopathy with loss of luminal biliary epithelium has been proposed to activate PBG, resulting in cell proliferation and differentiation to restore biliary epithelial integrity. However, formal evidence for this concept in human livers is lacking. We, therefore, developed a novel ex vivo model using precision-cut slices of extrahepatic human bile ducts obtained from discarded donor livers, providing an intact anatomical organization of cell structures, to study spatiotemporal differentiation and migration of PBG cells after severe biliary injury. Post-ischemic bile duct slices were incubated in oxygenated culture medium for up to a week. At baseline, severe tissue injury was evident with loss of luminal epithelial lining and mural stroma necrosis. In contrast, PBG remained relatively well preserved and different reactions of PBG were noted, including PBG dilatation, cell proliferation and maturation. Proliferation of PBG cells increased after 24 h of oxygenated incubation, reaching a peak after 72 h. Proliferation of PBG cells was paralleled by a reduction in PBG apoptosis and differentiation from a primitive and pluripotent (Nanog+/Sox9+) to a mature (CFTR+/secretin receptor+) and activated phenotype (increased expression of HIF-1α, Glut-1, and VEGF-A). Migration of proliferating PBG cells in our ex vivo model was unorganized, but resulted in generation of epithelial monolayers at stromal surfaces. CONCLUSION: Human PBG contain biliary progenitor cells and are able to respond to bile duct epithelial loss with proliferation, differentiation, and maturation to restore epithelial integrity. The ex vivo spatiotemporal behaviour of human PBG cells provides evidence for a pivotal role of PBG in biliary regeneration after severe injury. This article is protected by copyright. All rights reserved