The expanding bipolar shell of the helium nova V445 Puppis

From multi-epoch adaptive optics imaging and integral field unit spectroscopy, we report the discovery of an expanding and narrowly confined bipolar shell surrounding the helium nova V445 Puppis (Nova Puppis 2000). An equatorial dust disc obscures the nova remnant, and the outflow is characterized by a large polar outflow velocity of 6720 +/- 650 km s(-1) and knots moving at even larger velocities of 8450 +/- 570 km s(-1). We derive an expansion parallax distance of 8.2 +/- 0.5 kpc and deduce a pre-outburst luminosity of the underlying binary of log L/L-circle dot = 4.34 +/- 0.36. The derived luminosity suggests that V445 Puppis probably contains a massive white dwarf accreting at high rate from a helium star companion making it part of a population of binary stars that potentially lead to supernova Ia explosions due to accumulation of helium-rich material on the surface of a massive white dwarf

The AM Canum Venaticorum binary SDSS J173047.59+554518.5

The AM Canum Venaticorum (AM CVn) binaries are a rare group of hydrogen-deficient, ultrashort period, mass-transferring white dwarf binaries and are possible progenitors of Type Ia supernovae. We present time-resolved spectroscopy of the recently discovered AM CVn binary SDSS J173047.59+554518.5. The average spectrum shows strong double-peaked helium emission lines, as well as a variety of metal lines, including neon; this is the second detection of neon in an AM CVn binary, after the much brighter system GP Com. We detect no calcium in the accretion disc, a puzzling feature that has been noted in many of the longer period AM CVn binaries. We measure an orbital period, from the radial velocities of the emission lines, of 35.2 ± 0.2 min, confirming the ultracompact binary nature of the system. The emission lines seen in SDSS J1730 are very narrow, although double-peaked, implying a low-inclination, face-on accretion disc; using the measured velocities of the line peaks, we estimate i ≤ 11°. This low inclination makes SDSS J1730 an excellent system for the identification of emission lines

Feasibility of family group conference to promote return-to-work of persons receiving work disability benefit

Purpose: To investigate the feasibility of Family Group Conference for promoting return to work by clients receiving work disability benefits from the Social Security Institute in the Netherlands. Methods: We conducted a mixed-method pre- post-intervention feasibility study, using questionnaires, semi-structured interviews and return to work plans drafted in Family Group Conferences. A convenient sample of Labour experts, Clients, and Facilitators was followed for a period of six months. Feasibility outcomes were demand, acceptability, implementation and limited efficacy of perceived mental health and level of participation. Results: Fourteen labour experts and sixteen facilitators enrolled in the study. Of 28 eligible clients, nine (32%) participated in a Family Group Conference. About 78% of the Family Group Conferences were implemented as planned. Participant satisfaction about Family Group Conference was good (mean score 7). Perceived mental health and level of participation improved slightly during follow-up. Most actions in the return to work plans were work related. Most frequently chosen to take action was the participating client himself, supported by significant others in his or her social network. Six months after the Family Group Conference five participating clients returned to paid or voluntary work. Conclusions: Family Group Conference seems a feasible intervention to promote return to work by clients on work disability benefit. Involvement of the social network may have added value to support the clients in this process. An effectiveness study to further develop and test Family Group Conferences is recommended

Interference with the Mate-Finding Communication System of the Obliquebanded Leafroller (Lepidoptera: Tortricidae) Using Synthetic Sex Pheromones

Effect of atmospheric permeation with synthetic sex pheromone on the behavior and control of obliquebanded leafroller, Choristoneura rosaceana (Harris), was studied in small and large plots in commercial apple orchards. Synthetic sex pheromone significantly reduced the ability of male moths to locate pheromone-baited traps and tethered females; however, no differences were found among 3 pheromone rates. Location of pheromone dispensers within the tree canopy did not alter the number of males locating pheromone-baited traps and mating tethered females. Obliquebanded leafroller activity was greatest in the upper positions of the tree canopy and no edge effect was observed around perimeters of large disrupted blocks. The presence of gravid feral females, mated tethered females, high larval densities, and fruit damage within large pheromone disrupted blocks indicate obliqubanded leafrollers mate in orchards treated with synthetic sex pheromone. However, fruit damage caused by obliquebanded leafroller larvae was similar in pheromone, pheromone plus insecticide, and insecticide treatment

Reduced protein diffusion rate by cytoskeleton in vegetative and polarized Dictyostelium cells

Fluorescence recovery after photobleaching measurements with high spatial resolution are performed to elucidate the impact of the actin cytoskeleton on translational mobility of green fluorescent protein (GFP) in aqueous domains of Dictyostelium discoideum amoebae. In vegetative Dictyostelium cells, GFP molecules experience a 3.6-fold reduction of their translational mobility relative to dilute aqueous solutions. In disrupting the actin filamentous network using latrunculin-A, the intact actin cytoskeletal network is shown to contribute an effective viscosity of 1.36 cP, which accounts for 53% of the restrained molecular diffusion of GFP. The remaining 47% of hindered protein motions is ascribed to other mechanical barriers and the viscosity of the cell liquid. A direct correlation between the density of the actin network and its limiting action on protein diffusion is furthermore established from measurements under different osmotic conditions. In highly locomotive polarized cells, the obstructing effect of the actin filamentous network is seen to decline to 0.46 cP in the non-cortical regions of the cell. Our results indicate that the meshwork of actin filaments constitutes the primary mechanical barrier for protein diffusion and that any noticeable reorganization of the network is accompanied by altered intracellular protein mobility

Theory of adsorbate induced surface reconstruction on W(100)

We report results of a theoretical study on an adsorbate induced surface reconstruction. Hydrogen adsorption on a W(100) surface causes a switching transition in the symmetry of the displacements of the W atoms within the ordered c(2x2) phase. This transition is modeled by an effective Hamiltonian, where the hydrogen degrees of freedom are integrated out. Based on extensive Monte Carlo renormalisation group calculations we show that the switching transition is of second order at high temperatures and of first order at low temperatures. This behavior is qualitatively explained in terms of an XY model where there is an interplay between four and eight fold anisotropy fields. We also compare the calculated phase diagrams with a simple mean field theory.Comment: CSC Preprint, 31 pages (plain TeX file, no figures

A search for the hidden population of AM CVn binaries in the Sloan Digital Sky Survey

We present the latest results from a spectroscopic survey designed to uncover the hidden population of AM Canum Venaticorum (AM CVn) binaries in the photometric data base of the Sloan Digital Sky Survey (SDSS). We selected ∼2000 candidates based on their photometric colours, a relatively small sample which is expected to contain the majority of all AM CVn binaries in the SDSS (expected to be ∼50). We present two new candidate AM CVn binaries discovered using this strategy: SDSS J104325.08+563258.1 and SDSS J173047.59+554518.5. We also present spectra of 29 new cataclysmic variables, 23 DQ white dwarfs and 21 DZ white dwarfs discovered in this survey. The survey is now approximately 70 per cent complete, and the discovery of seven new AM CVn binaries indicates a lower space density than previously predicted. From the essentially complete g ≤ 19 sample, we derive an observed space density of (5 ± 3) × 10^(−7) pc^(−3); this is lower than previous estimates by a factor of 3. The sample has been cross-matched with the GALEX All-Sky Imaging Survey data base, and with Data Release 9 of the United Kingdom Infrared Telescope (UKIRT) Infrared Deep Sky Survey (UKIDSS). The addition of UV photometry allows new colour cuts to be applied, reducing the size of our sample to ∼1100 objects. Optimizing our follow-up should allow us to uncover the remaining AM CVn binaries present in the SDSS, providing the larger homogeneous sample required to more reliably estimate their space density

Plasminogen activator‐1 overexpression decreases experimental postthrombotic vein wall fibrosis by a non‐vitronectin‐dependent mechanism

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/108289/1/jth12644.pd

A ZZ Ceti white dwarf in SDSS J133941.11+484727.5

We present time-resolved spectroscopy and photometry of the cataclysmic variable (CV) SDSSJ133941.11+484727.5 (SDSS1339) which has been discovered in the Sloan Digital Sky Survey Data Release 4. The orbital period determined from radial velocity studies is 82.524(24)min, close to the observed period minimum. The optical spectrum of SDSS1339 is dominated to 90% by emission from the white dwarf. The spectrum can be successfully reproduced by a three-component model (white dwarf, disc, secondary) with Twd=12500K for a fixed log g=8.0, d=170pc, and a spectral type of the secondary later than M8. The mass transfer rate corresponding to the optical luminosity of the accretion disc is very low,~1.7x10^-13Msun/yr. Optical photometry reveals a coherent variability at 641s with an amplitude of 0.025mag, which we interpret as non-radial pulsations of the white dwarf. In addition, a long-period photometric variation with a period of either 320min or 344min and an amplitude of 0.025mag is detected, which bears no apparent relation with the orbital period of the system. Similar long-period photometric signals have been found in the CVs SDSSJ123813.73-033933.0, SDSSJ204817.85-061044.8, GW Lib and FS Aur, but so far no working model for this behaviour is available.Comment: MNRAS, in press, 8 pages, 10 figures, some figures downgraded to meet the file size constraint of arxiv.or

Invariant vector fields and the prolongation method for supersymmetric quantum systems

The kinematical and dynamical symmetries of equations describing the time evolution of quantum systems like the supersymmetric harmonic oscillator in one space dimension and the interaction of a non-relativistic spin one-half particle in a constant magnetic field are reviewed from the point of view of the vector field prolongation method. Generators of supersymmetries are then introduced so that we get Lie superalgebras of symmetries and supersymmetries. This approach does not require the introduction of Grassmann valued differential equations but a specific matrix realization and the concept of dynamical symmetry. The Jaynes-Cummings model and supersymmetric generalizations are then studied. We show how it is closely related to the preceding models. Lie algebras of symmetries and supersymmetries are also obtained.Comment: 37 pages, 7 table