Seeing deconvolution of globular clusters in M31

Seeing deconvolution of surface-brightness profiles using the regularized multi-Gaussian method is potentially a powerful method for extraction of morphological information from digital images. Here we illustrate this method by applying it to CCD images of six globular clusters in M31. We demonstrate that it is possible to make some judgments about the dynamical structure of M31 globulars, using good-seeing, deconvolved CCD images obtained from the ground; for example, whether they have post-core-collapse morphology or not. The effective resolution limit of the method is about 0.1-0.3 arcsec, for the CCD images obtained in FWHM ≃ 1 arcsec seeing, and sampling of 0.3 arcsec/pixel. We also demonstrate the robustness of the method, i.e., its insensivity to the exact choices of the functional representation of the point-spread function, details of the deconvolution technique, etc. The situation is equivalent in terms of angular resolution and sampling to observing globular clusters in the Virgo Cluster (e.g., around M87) with the Hubble Space Telescope, and the methods demonstrated here may be applied to HST data in the future. Dynamical structure of globular clusters, e.g., propensity for the post-core-collapse morphology as a function of position in the host galaxy, reflects the global dynamical evolution of a globular cluster system, as was already demonstrated for our galaxy. Similar studies of large samples of globulars in M31 and other Local Group galaxies from the ground, and out to Virgo with the HST, can provide valuable insights about the mass distribution in galaxies, and the formation and evolution of their globular cluster systems. This pilot study is a step in this direction

StarFinder: an IDL GUI based code to analyze crowded fields with isoplanatic correcting PSF fitting

StarFinder is a new code for the deep analysis of stellar fields, designed for well-sampled images with high and low Strehl ratio. It is organized in the form of a self-contained IDL widget-based application, with a 'user-friendly' graphic interface. We give here a general description of the code along with some applications to real data with space-invariant Point Spread Function (PSF). We present also some methods to handle anisoplanatic effects in wide-field Adaptive Optics (AO)observations.Comment: 9 pages, to to be published on "Proceeedings of Adaptive Optical Systems Technology",Proc.of SPIE,Vol.4007,2000. In pres

Analysis of isoplanatic high resolution stellar fields by Starfinder code

We describe a new code for the deep analysis of stellar fields, designed for Adaptive Optics Nyquist-sampled images with high and low Strehl ratio. The Point Spread Function is extracted directly from the image frame, to take into account the actual structure of the instrumental response and the atmospheric effects. The code is written in IDL language and organized in the form of a self-contained widget-based application, provided with a series of tools for data visualization and analysis. A description of the method and some applications to AO data are presented.Comment: 10 pages, 13 figures. Accepted for publication in Astron.& Astrophys. Sup. Se

Streamlined design of a self-inactivating feline immunodeficiency virus vector for transducing ex vivo dendritic cells and T lymphocytes.

BACKGROUND: Safe and efficient vector systems for delivering antigens or immunomodulatory molecules to dendritic cells (DCs), T lymphocytes or both are considered effective means of eliciting adaptive immune responses and modulating their type, extent, and duration. As a possible tool toward this end, we have developed a self-inactivating vector derived from feline immunodeficiency virus (FIV) showing performance characteristics similar to human immunodeficiency virus-derived vectors but devoid of the safety concerns these vectors have raised. METHODS: The pseudotyped FIV particles were generated with a three-plasmid system consisting of: the packaging construct, providing Gag, Pol and the accessory proteins; the vector(s), basically containing FIV packaging signal (psi), Rev responsive element, R-U5 region at both ends, and the green fluorescent protein as reporter gene; and the Env plasmid, encoding the G protein of vesicular stomatitis virus (VSV-G) or the chimeric RD114 protein. Both packaging and vector constructs were derived from p34TF10, a replication competent molecular clone of FIV. The pseudotyped particles were produced by transient transfection in the Crandell feline fibroblast kidney (CrFK) or the human epithelial (293T) cell line. RESULTS: To broaden its species tropism, the final vector construct was achieved through a series of intermediate constructs bearing a longer psi, the FIV central polypurin tract sequence (cPPT), or the woodchuck hepatitis post-regulatory element (WPRE). These constructs were compared for efficiency and duration of transduction in CrFK or 293T cells and in the murine fibroblast cell line NIH-3T3. Whereas psi elongation and cPPT addition did not bring any obvious benefit, insertion of WPRE downstream GFP greatly improved vector performances. To maximize the efficiency of transduction for ex-vivo murine DCs and T-lymphocytes, this construct was tested with VSV-G or RD114 and using different transduction protocols. The results indicated that the FIV construct derived herein stably transduced both cell types, provided that appropriate vector makeup and transduction protocol were used. Further, transduced DCs underwent changes suggestive of an induced maturation. CONCLUSION: In contrast to previously described FIV vectors that were poorly efficient in delivering genetic material to DCs and T lymphocytes, the vector developed herein has potential for use in experimental immunization strategies

Seeing deconvolution of globular clusters in M31

Seeing deconvolution of surface-brightness profiles using the regularized multi-Gaussian method is potentially a powerful method for extraction of morphological information from digital images. Here we illustrate this method by applying it to CCD images of six globular clusters in M31. We demonstrate that it is possible to make some judgments about the dynamical structure of M31 globulars, using good-seeing, deconvolved CCD images obtained from the ground; for example, whether they have post-core-collapse morphology or not. The effective resolution limit of the method is about 0.1-0.3 arcsec, for the CCD images obtained in FWHM ≃ 1 arcsec seeing, and sampling of 0.3 arcsec/pixel. We also demonstrate the robustness of the method, i.e., its insensivity to the exact choices of the functional representation of the point-spread function, details of the deconvolution technique, etc. The situation is equivalent in terms of angular resolution and sampling to observing globular clusters in the Virgo Cluster (e.g., around M87) with the Hubble Space Telescope, and the methods demonstrated here may be applied to HST data in the future. Dynamical structure of globular clusters, e.g., propensity for the post-core-collapse morphology as a function of position in the host galaxy, reflects the global dynamical evolution of a globular cluster system, as was already demonstrated for our galaxy. Similar studies of large samples of globulars in M31 and other Local Group galaxies from the ground, and out to Virgo with the HST, can provide valuable insights about the mass distribution in galaxies, and the formation and evolution of their globular cluster systems. This pilot study is a step in this direction

Development of Feline Immunodeficiency Virus ORF-A (tat) Mutants: In Vitro and in Vivo Characterization

AbstractA functional ORF-A is essential for efficient feline immunodeficiency virus replication in lymphocytes. We have characterized a series of mutants of the Petaluma strain, derived from p34TF10 and having different combinations of stop codons and increasingly long deletions in ORF-A. Six clones proved fully replicative in fibroblastoid Crandell feline kidney cells and monocyte-derived macrophage cultures but failed to replicate in T cell lines and primary lymphoblasts. Cats inoculated with three selected mutants had considerably milder infections than controls given intact ORF-A virus. In vivo, the mutants maintained growth properties similar to those in vitro for at least 7 months, except that replication in lymphoid cells was strongly reduced but not ablated. One mutant underwent extensive ORF-A changes without, however, reverting to wild-type. Antiviral immune responses were feeble in all cats, suggesting that viral loads were too low to represent a sufficiently powerful antigenic stimulus

Heart and Lungs in COPD. Close friends in real life - separate in daily medical practice?

Chronic obstructive pulmonary disease (COPD) is associated with a 2-3 times higher rate of cardiovascular disorders (CVD) which is independent of other risk factors. A low FEV1 is a specific predictor of mortality as a result of cardiac causes, even stronger than increased cholesterol: for each 10% reduction of FEV1, cardiovascular mortality increases by 28%. The main causes of death among COPD patients are of cardiovascular origin. COPD and CVD have two major risk factors in common - advanced age and tobacco smoking. The search for a pathogenetic link between the two conditions focuses mainly on systemic extension of pulmonary inflammation. Despite such a frequent association, pulmonologists and cardiologists in both the clinical and the research settings often underestimate the importance of a correct diagnosis and severity stratification of the two combined conditions. Spirometry, in particular, is largely underprescribed. Missed diagnosis and severity stratification, incomplete knowledge of adverse drug events and lack of resources lead to undertreatment of patients combining COPD and CVD, and in particular, the underuse of beta-blockers, inhaled bronchodilators and rehabilitation. Clinical studies focusing on this group of patients should be promoted in the future to test therapies and manage options. Furthermore, efforts must be made to improve the present standards of care, which falls short of recommended levels, starting from the often-neglected use of spirometry to confirm a diagnosis of COPD