University of Vienna

About: University of Vienna is a education organization based out in Vienna, Austria. It is known for research contribution in the topics: Population & Context (language use). The organization has 44686 authors who have published 95840 publications receiving 2907492 citations.

The APOKASC Catalog: An Asteroseismic and Spectroscopic Joint Survey of Targets in the Kepler Fields

Abstract: We present the first APOKASC catalog of spectroscopic and asteroseismic properties of 1916 red giants observed in the Kepler fields. The spectroscopic parameters provided from the Apache Point Observatory Galactic Evolution Experiment project are complemented with asteroseismic surface gravities, masses, radii, and mean densities determined by members of the Kepler Asteroseismology Science Consortium. We assess both random and systematic sources of error and include a discussion of sample selection for giants in the Kepler fields. Total uncertainties in the main catalog properties are of the order of 80 K in T eff, 0.06 dex in [M/H], 0.014 dex in log g, and 12% and 5% in mass and radius, respectively; these reflect a combination of systematic and random errors. Asteroseismic surface gravities are substantially more precise and accurate than spectroscopic ones, and we find good agreement between their mean values and the calibrated spectroscopic surface gravities. There are, however, systematic underlying trends with T eff and log g. Our effective temperature scale is between 0 and 200 K cooler than that expected from the infrared flux method, depending on the adopted extinction map, which provides evidence for a lower value on average than that inferred for the Kepler Input Catalog (KIC). We find a reasonable correspondence between the photometric KIC and spectroscopic APOKASC metallicity scales, with increased dispersion in KIC metallicities as the absolute metal abundance decreases, and offsets in T eff and log g consistent with those derived in the literature. We present mean fitting relations between APOKASC and KIC observables and discuss future prospects, strengths, and limitations of the catalog data.

A pooled analysis of 2 placebo-controlled 18-month trials of lamotrigine and lithium maintenance in bipolar I disorder.

Abstract: Background: Two clinical trials, prospectively designed for combined analysis, compared placebo, lithium, and lamotrigine for treatment of bipolar I disorder in recently depressed or manic patients. Method: 1315 bipolar I patients (DSM-IV) enrolled in the initial open-label phase, and 638 were stabilized and randomly assigned to 18 months of double-blind monotherapy with lamotrigine (N = 280; 50-400 mg/day fixed dose or 100-400 mg/day flexible dose), lithium (N = 167; serum level of 0.8-1.1 mEq/L), or placebo (N = 191). The primary endpoint was time from randomization to intervention for a mood episode. Data were gathered from August 1997 to August 2001. Results: Lamotrigine and lithium were superior to placebo for time to intervention for any mood episode (median survival: placebo, 86 days [95% CI = 58 to 121]; lithium, 184 days [95% CI = 119 to not calculable]; lamotrigine, 197 days [95% CI = 144 to 388]). Lamotrigine was superior to placebo for time to intervention for depression (median survival: placebo, 270 days [95% CI = 138 to not calculable]; lithium, median not calculable; lamotrigine, median not calculable). Lithium and lamotrigine were superior to placebo for time to intervention for mania (median survival not calculable for any group). Results of additional analyses adjusted for index mood were similar; however, only lithium was superior to placebo for intervention for mania. There was no evidence that either active treatment caused affective switch. Adverse event analysis indicated more diarrhea (19% vs. 7%, p <.05) and tremor (15% vs. 4%, p <.05) in lithium-treated patients compared with lamotrigine-treated patients. Conclusions: Lamotrigine and lithium stabilized mood by delaying the time to treatment for a mood episode. Lamotrigine was effective against depression and mania, with more robust activity against depression. Lithium was effective against mania.

Vasoactive intestinal peptide as a new drug for treatment of primary pulmonary hypertension

Abstract: Primary pulmonary hypertension is a fatal disease causing progressive right heart failure within 3 years after diagnosis. We describe a new concept for treatment of the disease using vasoactive intestinal peptide, a neuropeptide primarily functioning as a neurotransmitter that acts as a potent systemic and pulmonary vasodilator. Our rationale is based on the finding of a deficiency of the peptide in serum and lung tissue of patients with primary pulmonary hypertension, as evidenced by radioimmunoassay and immunohistochemistry. The relevance of this finding is underlined by an upregulation of corresponding receptor sites as shown by Northern blot analysis, Western blot analysis, and immunological techniques. Consequently, the substitution with the hormone results in substantial improvement of hemodynamic and prognostic parameters of the disease without side effects. It decreased the mean pulmonary artery pressure in our eight study patients, increased cardiac output, and mixed venous oxygen saturation. Our data provide enough proof for further investigation of vasoactive intestinal peptide and its role in primary pulmonary hypertension.

Bound for the Kinetic Energy of Fermions Which Proves the Stability of Matter

Abstract: We first prove that Σ |e (V)|, the sum of the negative energies of a single particle in a potential V, is bounded above by (4/15 π )∫|V|5/2. This in turn, implies a lower bound for the kinetic energy of N fermions of the form 3/5 (3π/4)2/3 ∫ρ 5/3, where ρ (x) is the one-particle density. From this, using the no-binding theorem of Thomas-Fermi theory, we present a short proof of the stability of matter with a reasonable constant for the bound.

Confined linear carbon chains as a route to bulk carbyne.

Abstract: Strong chemical activity and extreme instability in ambient conditions characterize carbyne, an infinite sp1 hybridized carbon chain. As a result, much less has been explored about carbyne as compared to other carbon allotropes such as fullerenes, nanotubes and graphene. Although end-capping groups can be used to stabilize carbon chains, length limitations are still a barrier for production, and even more so for application. We report a method for the bulk production of long acetylenic linear carbon chains protected by thin double-walled carbon nanotubes. The synthesis of very long arrangements is confirmed by a combination of transmission electron microscopy, X-ray diffraction and (near-field) resonance Raman spectroscopy. Our results establish a route for the bulk production of exceptionally long and stable chains composed of more than 6,000 carbon atoms, representing an elegant forerunner towards the final goal of carbyne’s bulk production. One-dimensional linear carbon chains reaching a length close to 800 nm have been synthesized at high temperature and high vacuum using double-walled carbon nanotubes as nanoreactors.