All quiet in the outer halo: chemical abundances in the globular cluster Pal 3

Context: Globular clusters (GCs) in the outer halo are important probes of the composition and origin of the Galactic stellar halo. Aims: We derive chemical element abundance ratios in red giants belonging to the remote (R~90 kpc) GC Pal 3 and compare our measurements to those for red giant stars in both inner and outer halo GCs. Methods: From high-resolution spectroscopy of four red giants, obtained with the Magellan/MIKE spectrograph at moderately high S/N, we derive chemical abundances for 25 alpha-, iron peak-, and neutron-capture elements. These abundance ratios are confirmed by co-adding low S/N HIRES spectra of 19 stars along the red giant branch. Results: Pal 3 shows alpha-enhanced abundance patterns, and also its Fe-peak and neutron-capture element ratios, are fully compatible with those found in halo field stars and representative inner halo GCs of the same metallicity (such as M 13). The heavy elements in Pal 3 appear to be governed by r-process nucleosyn-thesis. Our limited sample does not show any significant star-to-star abundance variations in this cluster, although a weak Na-O anti-correlation cannot be ruled out by the present data. Conclusions: Pal 3 thus appears as an archetypical GC with abundance ratios dissimilar to dwarf spheroidal stars, ruling out a direct connection to such external systems. This conclusion is underscored by the lack of significant abundance spreads in this GC, in contrast to the broad abundance distributions seen in the dwarf galaxies. Pal 3 appears to have evolved chemically coeval with the majority of GCs belonging to Galactic inner and outer halo, experiencing a similar enrichment history.Comment: 16 pages, 13 figures, accepted for publication in Astronomy and Astrophysic

Non-holomorphic Corrections from Threebranes in F Theory

We construct solutions of type IIB supergravity dual to N=2 super Yang-Mills theories. By considering a probe moving in a background with constant coupling and an AdS_{5} component in its geometry, we are able to reproduce the exact low energy effective action for the theory with gauge group SU(2) and N_{f}=4 massless flavors. After turning on a mass for the flavors we find corrections to the AdS_{5} geometry. In addition, the coupling shows a power law dependence on the energy scale of the theory. The origin of the power law behaviour of the coupling is traced back to instanton corrections. Instanton corrections to the four derivative terms in the low energy effective action are correctly obtained from a probe analysis. By considering a Wilson loop in this geometry we are also able to compute the instanton effects on the quark-antiquark potential. Finally we consider a solution corresponding to an asymptotically free field theory. Again, the leading form of the four derivative terms in the low energy effective action are in complete agreement with field theory expectations.Comment: 23 pages, uses harvmac, References added, typos corrected and minor improvements to discussion of N dependence, to appear in Phys. Rev.

Direct determination of trace elements in powdered samples by in-cell isotope dilution femtosecond laser ablation ICPMS

A method has been developed for the direct and simultaneous multielement determination of Cu, Zn, Sn, and Pb in soil and sediment samples using femtosecond laser ablation inductively coupled plasma mass spectrometry (fs-LA-ICPMS) in combination with isotope dilution mass spectrometry (IDMS). The in-cell isotope dilution fs-LA-ICPMS method proposed in this work was based on the quasi-simultaneous ablation of the natural abundance sample and the isotopically enriched solid spike, which was performed using a high repetition rate laser and a fast scanning beam device in a combined manner. Both the sample preparation procedure and the total analysis time have been drastically reduced, in comparison with previous approaches, since a unique multielement isotopically enriched solid spike was employed to analyze different powdered samples. Numerous experimental parameters were carefully selected (e.g., carrier gas flow rate, inlet diameter of the ablation cell, sample translation speed, scanner speed, etc.) in order to ensure the complete mixing between the sample and the solid spike aerosols. The proposed in-cell fs-LA-ICP-IDMS method was tested for the analysis of two soil (CRM 142R, GBW-07405) and two sediment (PACS-2, IAEA-405) reference materials, and the analysis of Cu, Zn, Sn, and Pb yielded good agreement of usually not more than 10% deviation from the certified values and precisions of less than 15% relative standard deviation. Furthermore, the concentrations were in agreement not only with the certified values but also with those obtained by ICP-IDMS after the microwave-assisted digestion of the solid samples, demonstrating therefore that in-cell fs-LA-ICP-IDMS opens the possibility for accurate and precise determinations of trace elements in powdered samples reducing the total sample preparation time to less than 5 min. Additionally, scanning electron microscope measurements showed that the aerosol generated by in-cell fs-LA-ICP-IDMS predominantly consisted of linear agglomerates of small particles (in the order of few tens of nanometers) and a few large spherical particles with diameters below 225 nm

Strong Directional Out-of-Plane Scattering in Multiple Ionizing Highly Charged Ion-Atom Collisions

The azimuthal ({phi}{sub r}) and polar angle ({theta}{sub r}) scattering of projectiles in coincidence with recoil ions has been studied for 0.53 MeV/u F{sup 8+} + Ne. For high degree of ionization of the target we find the resultant transverse momentum of all electrons emitted into the continuum to increase with the number of ejected electrons and to have a direction mostly not co-planar with the scattering plane

Radiological and pathological findings of a metastatic composite paraganglioma with neuroblastoma in a man: a case report

INTRODUCTION: Composite tumors of the adrenal medulla or paraganglia are extremely rare and present a diagnostic dilemma. These tumors consist of a neuroendocrine component mixed with a neural component.We describe the imaging characteristics together with the corresponding pathological findings of a composite tumor. Apart from any component-specific imaging findings, the hallmark of this entity is the presence of histologically distinguishable components. CASE PRESENTATION: A 61-year-old Caucasian man was referred to our hospital due to a suspect lesion found on chest computed tomography carried out for unclear thoracic pain. An abdominal computed tomography scan and ultrasound examination detected a retroperitoneal tumor comprising two different tumor components. Twenty-four-hour urine revealed high levels of normetanephrine, characteristic of a neuroendocrine tumor. An octreoscan prior to surgical procedures revealed multiple osseous and intra-hepatic metastases. The final histopathological workup revealed a composite paraganglioma with neuroblastoma. Our patient died ten months after the initial diagnosis from tumor-associated complications. CONCLUSIONS: Composite paragangliomas with neuroblastoma are rare tumors of the retroperitoneum. Such tumors should be considered in the differential diagnosis of retroperitoneal masses

Precise Modeling of the Exoplanet Host Star and CoRoT Main Target HD 52265

This paper presents a detailed and precise study of the characteristics of the Exoplanet Host Star and CoRoT main target HD 52265, as derived from asteroseismic studies. The results are compared with previous estimates, with a comprehensive summary and discussion. The basic method is similar to that previously used by the Toulouse group for solar-type stars. Models are computed with various initial chemical compositions and the computed p-mode frequencies are compared with the observed ones. All models include atomic diffusion and the importance of radiative accelerations is discussed. Several tests are used, including the usual frequency combinations and the fits of the \'echelle diagrams. The possible surface effects are introduced and discussed. Automatic codes are also used to find the best model for this star (SEEK, AMP) and their results are compared with that obtained with the detailed method. We find precise results for the mass, radius and age of this star, as well as its effective temperature and luminosity. We also give an estimate of the initial helium abundance. These results are important for the characterization of the star-planet system.Comment: 9 pages, 6 figures, 7 tables, to be published in Astronomy and Astrophysic

Ground-state properties of tubelike flexible polymers

In this work we investigate structural properties of native states of a simple model for short flexible homopolymers, where the steric influence of monomeric side chains is effectively introduced by a thickness constraint. This geometric constraint is implemented through the concept of the global radius of curvature and affects the conformational topology of ground-state structures. A systematic analysis allows for a thickness-dependent classification of the dominant ground-state topologies. It turns out that helical structures, strands, rings, and coils are natural, intrinsic geometries of such tubelike objects

A pivotal role for starch in the reconfiguration of 14C-partitioning and allocation in Arabidopsis thaliana under short-term abiotic stress.

Plant carbon status is optimized for normal growth but is affected by abiotic stress. Here, we used 14C-labeling to provide the first holistic picture of carbon use changes during short-term osmotic, salinity, and cold stress in Arabidopsis thaliana. This could inform on the early mechanisms plants use to survive adverse environment, which is important for efficient agricultural production. We found that carbon allocation from source to sinks, and partitioning into major metabolite pools in the source leaf, sink leaves and roots showed both conserved and divergent responses to the stresses examined. Carbohydrates changed under all abiotic stresses applied; plants re-partitioned 14C to maintain sugar levels under stress, primarily by reducing 14C into the storage compounds in the source leaf, and decreasing 14C into the pools used for growth processes in the roots. Salinity and cold increased 14C-flux into protein, but as the stress progressed, protein degradation increased to produce amino acids, presumably for osmoprotection. Our work also emphasized that stress regulated the carbon channeled into starch, and its metabolic turnover. These stress-induced changes in starch metabolism and sugar export in the source were partly accompanied by transcriptional alteration in the T6P/SnRK1 regulatory pathway that are normally activated by carbon starvation

Reddening and Extinction Toward the Galactic Bulge from OGLE-III: The Inner Milky Way's Rv ~ 2.5 Extinction Curve

We combine VI photometry from OGLE-III with VVV and 2MASS measurements of E(J-K_{s}) to resolve the longstanding problem of the non-standard optical extinction toward the Galactic bulge. We show that the extinction is well-fit by the relation A_{I} = 0.7465*E(V-I) + 1.3700*E(J-K_{s}), or, equivalently, A_{I} = 1.217*E(V-I)(1+1.126*(E(J-K_{s})/E(V-I)-0.3433)). The optical and near-IR reddening law toward the inner Galaxy approximately follows an R_{V} \approx 2.5 extinction curve with a dispersion {\sigma}_{R_{V}} \approx 0.2, consistent with extragalactic investigations of the hosts of type Ia SNe. Differential reddening is shown to be significant on scales as small as as our mean field size of 6', with the 1{\sigma} dispersion in reddening averaging 9% of total reddening for our fields. The intrinsic luminosity parameters of the Galactic bulge red clump (RC) are derived to be (M_{I,RC}, \sigma_{I,RC,0}, (V-I)_{RC,0}, \sigma_{(V-I)_{RC}}, (J-K_{s})_{RC,0}) = (-0.12, 0.09, 1.06, 0.121, 0.66). Our measurements of the RC brightness, brightness dispersion and number counts allow us to estimate several Galactic bulge structural parameters. We estimate a distance to the Galactic center of 8.20 kpc, resolving previous discrepancies in distance determinations to the bulge based on I-band observations. We measure an upper bound on the tilt {\alpha} \approx 40{\deg}. between the bar's major axis and the Sun-Galactic center line of sight, though our brightness peaks are consistent with predictions of an N-body model oriented at {\alpha} \approx 25{\deg}. The number of RC stars suggests a total stellar mass for the Galactic bulge of 2.0*10^{10} M_{\odot}, if one assumes a Salpeter IMF.Comment: 61 Pages, 21 Figures, 4 Tables, Submitted to The Astrophysical Journal and modified as per a referee report. Includes reddening, reddening law, differential reddening, mean distance, dispersion in distance, surface density of stars and errors thereof for ~9,000 bulge sightlines. For a brief video explaining the key result of this paper, see http://www.youtube.com/user/OSUAstronom

Tidal Evolution of Close-in Planets

Recent discoveries of several transiting planets with clearly non-zero eccentricities and some large inclinations started changing the simple picture of close-in planets having circular and well-aligned orbits. Two major scenarios to form such planets are planet migration in a disk, and planet--planet interactions combined with tidal dissipation. The former scenario can naturally produce a circular and low-obliquity orbit, while the latter implicitly assumes an initially highly eccentric and possibly high-obliquity orbit, which are then circularized and aligned via tidal dissipation. We investigate the tidal evolution of transiting planets on eccentric orbits. We show that the current and future orbital evolution of these systems is likely dominated by tidal dissipation, and not by a more distant companion. Although most of these close-in planets experience orbital decay all the way to the Roche limit, there are two characteristic evolution paths for them, depending on the relative efficiency of tidal dissipation inside the star and the planet. We point out that the current observations may be consistent with one of them. Our results suggest that at least some of the close-in planets with non-zero orbital eccentricity may have been formed by tidally circularizing an initially eccentric orbit. We also find that even when the stellar spin-orbit misalignment is observed to be small at present, some systems could have had a highly misaligned orbit in the past. Finally, we also re-examine the recent claim by Levrard et. al., who found that all orbital and spin parameters evolve on a similar timescale to orbital decay.Comment: Accepted for publication in ApJ, 22 pages, 19 figures, 2 tables, Corrupted figures are fixe