The complex morphology of the young disk MWC 758: Spirals and dust clumps around a large cavity

We present Atacama Large Millimeter Array (ALMA) observations at an angular resolution of 0.1-0.2" of the disk surrounding the young Herbig Ae star MWC 758. The data consist of images of the dust continuum emission recorded at 0.88 millimeter, as well as images of the 13CO and C18O J = 3-2 emission lines. The dust continuum emission is characterized by a large cavity of roughly 40 au in radius which might contain a mildly inner warped disk. The outer disk features two bright emission clumps at radii of about 47 and 82 au that present azimuthal extensions and form a double-ring structure. The comparison with radiative transfer models indicates that these two maxima of emission correspond to local increases in the dust surface density of about a factor 2.5 and 6.5 for the south and north clumps, respectively. The optically thick 13CO peak emission, which traces the temperature, and the dust continuum emission, which probes the disk midplane, additionally reveal two spirals previously detected in near-IR at the disk surface. The spirals seen in the dust continuum emission present, however, a slight shift of a few au towards larger radii and one of the spirals crosses the south dust clump. Finally, we present different scenarios in order to explain the complex structure of the disk.Comment: 15 pages, 11 figures. The paper has been published in ApJ. References added and typos correcte

Dynamical Masses of Low Mass Stars in the Taurus and Ophiuchus Star Forming Regions

We report new dynamical masses for 5 pre-main sequence (PMS) stars in the L1495 region of the Taurus star-forming region (SFR) and 6 in the L1688 region of the Ophiuchus SFR. Since these regions have VLBA parallaxes these are absolute measurements of the stars' masses and are independent of their effective temperatures and luminosities. Seven of the stars have masses $<0.6$ solar masses, thus providing data in a mass range with little data, and of these, 6 are measured to precision $< 5 \%$. We find 8 stars with masses in the range 0.09 to 1.1 solar mass that agree well with the current generation of PMS evolutionary models. The ages of the stars we measured in the Taurus SFR are in the range 1-3 MY, and $<1$ MY for those in L1688. We also measured the dynamical masses of 14 stars in the ALMA archival data for Akeson~\&~Jensen's Cycle 0 project on binaries in the Taurus SFR. We find that the masses of 7 of the targets are so large that they cannot be reconciled with reported values of their luminosity and effective temperature. We suggest that these targets are themselves binaries or triples.Comment: 20 page

Melting of tantalum at high pressure determined by angle dispersive x-ray diffraction in a double-sided laser-heated diamond-anvil cell

The high pressure and high temperature phase diagram of Ta has been studied in a laser-heated diamond-anvil cell (DAC) using x-ray diffraction measurements up to 52 GPa and 3800 K. The melting was observed at nine different pressures, being the melting temperature in good agreement with previous laser-heated DAC experiments, but in contradiction with several theoretical calculations and previous piston-cylinder apparatus experiments. A small slope for the melting curve of Ta is estimated (dTm/dP = 24 K/GPa at 1 bar) and a possible explanation for this behaviour is given. Finally, a P-V-T equation of states is obtained, being the temperature dependence of the thermal expansion coefficient and the bulk modulus estimated.Comment: 31 pages, 8 figures, to appear in J.Phys.:Cond.Matte

Not all intravenous immunoglobulin preparations are equally well tolerated

Intravenous immunoglobulin (IVIG) is used for many indications beyond the original substitution in primary antibody deficiency. Whereas many reports mention adverse reactions, no comparative data exist concerning the incidence of side-effects among the different brands of IVIG. We describe here our experience with the use of different IVIG formulations and their tolerability in a select cohort of 40 patients. The IVIG dose ranged from 0.4 to 3 g/kg/day and was given for 1–2742 days. Fourteen patients (35%) experienced mild to severe adverse reactions during or within 48 h of administration of standard IVIG preparation, which did not recur after switching to an alternative preparation. Adverse reactions included headache, fever, chills, nausea, emesis, hypotension and muscle cramps. One patient experienced a severe adverse reaction; he had a 3-day headache following IVIG infusion. Among the 16 patients who received alternative preparation initially, none experienced adverse reactions. In conclusion, this study shows that IVIG preparations are not all equally well tolerated in patients. The data suggest that, perhaps to a comparable extent to the preparation itself, the infusion rate has a major effect. If a reduction in the infusion rate does not minimize side-effects, one should consider switching the IVIG formulation

"Medikamente sind Bomben" - zum Metapherngebrauch von Lungentransplantations-Patienten mit guter oder ungenügender Compliance

Fragestellung: Nach einer Organtransplantation finden komplexe psychologische Verarbeitungsprozesse statt. In der vorliegenden Studie wurde untersucht, welche Metaphern im Zusammenhang mit Transplantationserfahrungen verwendet werden, und ob Unterschiede zwischen Patienten mit guter bzw. ungenügender Compliance im Gebrauch dieser Metaphern bestehen. Methode: 14 lungentransplantierte Patienten wurden in einem halbstrukturierten Interview zu ihren Transplantationserfahrungen befragt. Ihre Compliance wurde von den behandelnden Ärzten eingeschätzt. Die Auswertung der Interviews erfolgte anhand einer Metaphernanalyse, welche Hinweise auf vor- und unbewusste Vorstellungen der Patienten liefert. Die Interraterreliabilität über die Metapherngruppen war Cohen’s Kappa K = 0.8. Ergebnisse: Die Patienten konzeptualisierten ihren Körper, aber auch ihr Selbst als ein “Gefäß”, dass sowohl materielle (z.B. die Lunge) wie immaterielle Objekte (z.B. Gedanken an den Spender, Affekte) enthält. Der wichtigste Unterschied zwischen den Compliance-Gruppen bestand darin, dass Patienten mit ungenügender Compliance eine grössere Distanz zur transplantierten Lunge erlebten. Auch konzeptualisierten sie ihren Körper bzw. ihr Selbst nicht als ein Gefäß, das die Lunge enthält. Diskussion: Die Ergebnisse zeigen, dass gute Compliance mit einer erfolgreichen Organintegration assoziiert ist, welche die Zugehörigkeit der Lunge in einem als Gefäß konzeptualisierten Körper bzw. Selbst umfasst. Patienten mit ungenügender Compliance nehmen die Lunge eher als Fremdkörper wahr. Diese Verarbeitungsprozesse sind teils bewusster, teils vor- und unbewusster Natur

Structure and Dynamics of Liquid Iron under Earth's Core Conditions

First-principles molecular dynamics simulations based on density-functional theory and the projector augmented wave (PAW) technique have been used to study the structural and dynamical properties of liquid iron under Earth's core conditions. As evidence for the accuracy of the techniques, we present PAW results for a range of solid-state properties of low- and high-pressure iron, and compare them with experimental values and the results of other first-principles calculations. In the liquid-state simulations, we address particular effort to the study of finite-size effects, Brillouin-zone sampling and other sources of technical error. Results for the radial distribution function, the diffusion coefficient and the shear viscosity are presented for a wide range of thermodynamic states relevant to the Earth's core. Throughout this range, liquid iron is a close-packed simple liquid with a diffusion coefficient and viscosity similar to those of typical simple liquids under ambient conditions.Comment: 13 pages, 8 figure

Pressure tuning of structure, superconductivity and novel magnetic order in the Ce-underdoped electron-doped cuprate T'-Pr_1.3-xLa_0.7Ce_xCuO_4 (x = 0.1)

High-pressure neutron powder diffraction, muon-spin rotation and magnetization studies of the structural, magnetic and the superconducting properties of the Ce-underdoped superconducting (SC) electron-doped cuprate system T'-Pr_1.3-xLa_0.7Ce_xCuO_4 with x = 0.1 are reported. A strong reduction of the lattice constants a and c is observed under pressure. However, no indication of any pressure induced phase transition from T' to T structure is observed up to the maximum applied pressure of p = 11 GPa. Large and non-linear increase of the short-range magnetic order temperature T_so in T'-Pr_1.3-xLa_0.7Ce_xCuO_4 (x = 0.1) was observed under pressure. Simultaneously pressure causes a non-linear decrease of the SC transition temperature T_c. All these experiments establish the short-range magnetic order as an intrinsic and a new competing phase in SC T'-Pr_1.2La_0.7Ce_0.1CuO_4. The observed pressure effects may be interpreted in terms of the improved nesting conditions through the reduction of the in-plane and out-of-plane lattice constants upon hydrostatic pressure.Comment: 11 pages, 10 figure