Patient organizations and primary care development: reflections by patients with chronic diseases

To explore how patients with chronic diseases, as well as members of patient organizations, perceive primary care and how they think about how to participate in primary care development. Focus group interviews with 28 patients in three regions in Sweden were conducted. We identified four themes: Availability of care, How to be met by professionals, Information needs and Continuity and prevention in care. Important was to meet the same doctor at every visit and to be met with empathy and knowledge about your disease. Suggestions about better use of technical information services, introduction of a coordinator in the waiting room and longer and varied open hours came up. The information needs for newly diagnosed and those with a long disease trajectory differed and care treatment plans were asked for by many participants. Discussions between patient organizations about how to participate in education of health care professionals were recommended. Patients’ with chronic diseases want to take more active part in their own care. By promoting more contacts between patient organizations, influence on the politic agendas may be achieved. To achieve effects, the patient organizations should be proposed to be included and to activate themselves about these results. If so, a stronger patient voice may be heard in the society. A change in the paternalistic philosophy in primary health care is also needed so the patients’ rights and contribution will be acknowledged and joint education with health professionals could be one way

Variability of Young Massive Stars in the Galactic Super Star Cluster Westerlund 1

This paper presents the first optical variability study of the Westerlund 1 super star cluster in search of massive eclipsing binary systems. A total of 129 new variable stars have been identified, including the discovery of 4 eclipsing binaries that are cluster members, 1 additional candidate, 8 field binaries, 19 field delta Scuti stars, 3 field W UMa eclipsing binaries, 13 other periodic variables and 81 long period or non-periodic variables. These include the known luminous blue variable, the B[e] star, 11 Wolf-Rayet stars, several supergiants, and other reddened stars that are likely members of Westerlund 1. The bright X-ray source corresponding to the Wolf-Rayet star WR77o (B) is found to be a 3.51 day eclipsing binary. The discovery of a reddened detached eclipsing binary system implies the first identification of main-sequence stars in Westerlund 1.Comment: 28 pages, 9 figures, 3 tables; accepted for publication in The Astronomical Journal. Full-resolution version and color image of the cluster are available at http://www.dtm.ciw.edu/bonanos/Westerlund

A Rich Population of X-ray Emitting Wolf-Rayet Stars in the Galactic Starburst Cluster Westerlund 1

Recent optical and IR studies have revealed that the heavily-reddened starburst cluster Westerlund 1 (Wd 1) contains at least 22 Wolf-Rayet (WR) stars, comprising the richest WR population of any galactic cluster. We present results of a senstive Chandra X-ray observation of Wd 1 which detected 12 of the 22 known WR stars and the mysterious emission line star W9. The fraction of detected WN stars is nearly identical to that of WC stars. The WN stars WR-A and WR-B as well as W9 are exceptionally luminous in X-rays and have similar hard heavily-absorbed spectra with strong Si XIII and S XV emission lines. The luminous high-temperature X-ray emission of these three stars is characteristic of colliding wind binary systems but their binary status remains to be determined. Spectral fits of the X-ray bright sources WR-A and W9 with isothermal plane-parallel shock models require high absorption column densities log N$_{H}$ = 22.56 (cm$^{-2}$) and yield characteristic shock temperatures kT_shock ~ 3 keV (T ~ 35 MK).Comment: ApJL, 2006, in press (3 figures, 1 table

Comments on "The long-period Galactic Cepheid RS Puppis. I. A geometric distance from its light echoes"

The luminous Galactic Cepheid RS Puppis is unique in being surrounded by a dust nebula illuminated by the variable light of the Cepheid. In a recent paper in this journal, Kervella et al. (2008) report a very precise geometric distance to RS Pup, based on measured phase lags of the light variations of individual knots in the reflection nebula. In this commentary, we examine the validity of the distance measurement, as well as the reality of the spatial structure of the nebula determined by Feast (2008) based upon the phase lags of the knots. {Kervella et al. assumed that the illuminated dust knots lie, on average, in the plane of the sky (otherwise it is not possible to derive a geometric distance from direct imaging of light echoes). We consider the biasing introduced by the high efficiency of forward scattering. We conclude that most of the knots are in fact likely to lie in front of the plane of the sky, thus invalidating the Kervella et al. result. We also show that the flat equatorial disk structure determined by Feast is unlikely; instead, the morphology of the nebula is more probably bipolar, with a significant tilt of its axis with respect to the plane of the sky. Although the Kervella et al. distance result is invalidated, we show that high-resolution polarimetric imaging has the potential to yield a valid geometric distance to this important Cepheid.Comment: 10 pages, 5 figures, 1 table; accepted by Astronomy & Astrophysic

Hairpins in the conformations of a confined polymer

If a semiflexible polymer confined to a narrow channel bends around by 180 degrees, the polymer is said to exhibit a hairpin. The equilibrium extension statistics of the confined polymer are well understood when hairpins are vanishingly rare or when they are plentiful. Here we analyze the extension statistics in the intermediate situation via experiments with DNA coated by the protein RecA, which enhances the stiffness of the DNA molecule by approximately one order of magnitude. We find that the extension distribution is highly non-Gaussian, in good agreement with Monte Carlo simulations of confined discrete wormlike chains. We develop a simple model that qualitatively explains the form of the extension distribution. The model shows that the tail of the distribution at short extensions is determined by conformations with one hairpin.Comment: Revised version. 22 pages, 7 figures, 2 tables, supplementary materia

NGC 602 Environment, Kinematics and Origins

The young star cluster NGC 602 and its associated HII region, N90, formed in a relatively isolated and diffuse environment in the Wing of the Small Magellanic Cloud. Its isolation from other regions of massive star formation and the relatively simple surrounding HI shell structure allows us to constrain the processes that may have led to its formation and to study conditions leading to massive star formation. We use images from Hubble Space Telescope and high resolution echelle spectrographic data from the Anglo-Australian Telescope along with 21-cm neutral hydrogen (HI) spectrum survey data and the shell catalogue derived from it to establish a likely evolutionary scenario leading to the formation of NGC 602. We identify a distinct HI cloud component that is likely the progenitor cloud of the cluster and HII region which probably formed in blister fashion from the cloud's periphery. We also find that the past interaction of HI shells can explain the current location and radial velocity of the nebula. The surrounding Interstellar Medium is diffuse and dust-poor as demonstrated by a low visual optical depth throughout the nebula and an average HI density of the progenitor cloud estimated at 1 cm^-3. These conditions suggest that the NGC 602 star formation event was produced by compression and turbulence associated with HI shell interactions. It therefore represents a single star forming event in a low gas density region.Comment: Accepted for publication in PASP. 25 pages, 10 figure

Orientational correlations in confined DNA

We study how the orientational correlations of DNA confined to nanochannels depend on the channel diameter D by means of Monte Carlo simulations and a mean-field theory. This theory describes DNA conformations in the experimentally relevant regime where the Flory-de Gennes theory does not apply. We show how local correlations determine the dependence of the end-to-end distance of the DNA molecule upon D. Tapered nanochannels provide the necessary resolution in D to study experimentally how the extension of confined DNA molecules depends upon D. Our experimental and theoretical results are in qualitative agreement.Comment: Revised version including supplemental material, 7 pages, 8 figure

The Initial Mass Function of the Stellar Association NGC 602 in the Small Magellanic Cloud with Hubble Space Telescope ACS Observations

We present our photometric study of the stellar association NGC 602 in the wing of the Small Magellanic Cloud (SMC). The data were taken in the filters F555W and F814W using the Advanced Camera for Surveys (ACS) on-board the Hubble Space Telescope (HST). Photometry was performed using the ACS module of the stellar photometry package DOLPHOT. We detected more than 5,500 stars with a magnitude range of 14 \lsim m_{555} \lsim 28 mag. Three prominent stellar concentrations are identified with star counts in the observed field, the association NGC 602 itself, and two clusters, one of them not being currently in any known catalog. The Color-Magnitude Diagrams (CMDs) of both clusters show features typical for young open clusters, while that of the association reveals bright main sequence (MS) and faint pre-main sequence (PMS) stars as the members of the system. We construct the initial mass spectrum (IMS) of the association by applying an age-independent method of counting the PMS stars within evolutionary tracks, while for the bright MS stars we transform their magnitudes to masses with the use of mass-luminosity relations. The IMS of NGC 602 is found to be well represented by a single-power law, corresponding to an Initial Mass Function (IMF) of slope \Gamma\approx -1.2 for 1 \lsim M/M{\solar} \lsim 45. This indicates that the shape of the IMF of a star forming system in the SMC for stars with masses higher than 1 M{\solar} seems to be quite similar to the field IMF in the solar neighborhood.Comment: Accepted for publication in ApJ, 13 pages, 14 figures, emulateapj.cls LaTeX style, full resolution version available on http://www.astro.uni-bonn.de/~dgoulier/Science/NGC602/ms.pd

Extension of nano-confined DNA: quantitative comparison between experiment and theory

The extension of DNA confined to nanochannels has been studied intensively and in detail. Yet quantitative comparisons between experiments and model calculations are difficult because most theoretical predictions involve undetermined prefactors, and because the model parameters (contour length, Kuhn length, effective width) are difficult to compute reliably, leading to substantial uncertainties. Here we use a recent asymptotically exact theory for the DNA extension in the "extended de Gennes regime" that allows us to compare experimental results with theory. For this purpose we performed new experiments, measuring the mean DNA extension and its standard deviation while varying the channel geometry, dye intercalation ratio, and ionic buffer strength. The experimental results agree very well with theory at high ionic strengths, indicating that the model parameters are reliable. At low ionic strengths the agreement is less good. We discuss possible reasons. Our approach allows, in principle, to measure the Kuhn length and effective width of a single DNA molecule and more generally of semiflexible polymers in solution.Comment: Revised version, 6 pages, 2 figures, 1 table, supplementary materia

The long-period Galactic Cepheid RS Puppis - II. 3D structure and mass of the nebula from VLT/FORS polarimetry

The long-period Cepheid RS Pup is surrounded by a large dusty nebula reflecting the light from the central star. Due to the changing luminosity of the central source, light echoes propagate into the nebula. This remarkable phenomenon was the subject of Paper I.The origin and physical properties of the nebula are however uncertain: it may have been created through mass loss from the star itself, or it could be the remnant of a pre-existing interstellar cloud. Our goal is to determine the 3D structure of the nebula, and estimate its mass. Knowing the geometrical shape of the nebula will also allow us to retrieve the distance of RS Pup in an unambiguous manner using a model of its light echoes (in a forthcoming work). The scattering angle of the Cepheid light in the circumstellar nebula can be recovered from its degree of linear polarization. We thus observed the nebula surrounding RS Pup using the polarimetric imaging mode of the VLT/FORS instrument, and obtained a map of the degree and position angle of linear polarization. From our FORS observations, we derive a 3D map of the distribution of the dust, whose overall geometry is an irregular and thin layer. The nebula does not present a well-defined symmetry. Using a simple model, we derive a total dust mass of M(dust) = 2.9 +/- 0.9 Msun for the dust within 1.8 arcmin of the Cepheid. This translates into a total mass of M(gas+dust) = 290 +/- 120 Msun, assuming a dust-to-gas ratio of 1.0 +/- 0.3 %. The high mass of the dusty nebula excludes that it was created by mass-loss from the star. However, the thinness nebula is an indication that the Cepheid participated to its shaping, e.g. through its radiation pressure or stellar wind. RS Pup therefore appears as a regular long-period Cepheid located in an exceptionally dense interstellar environment.Comment: 14 pages, 21 figures. Accepted for publication in A&