1,634 research outputs found

    Unveiling the structure of the planetary nebula M 2-48: Kinematics and physical conditions

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    The kinematics and physical conditions of the bipolar planetary nebula M 2-48 are analysed from high and low dispersion long-slit spectra. Previous CCD narrow-band optical observations have suggested that this nebula is mainly formed by a pair of symmetric bow-shocks, an off-center semi-circular shell, and an internal bipolar structure. The bipolar outflow has a complex structure, characterised by a series of shocked regions located between the bright core and the polar tips. There is an apparent kinematic discontinuity between the bright bipolar core and the outer regions. The fragmented ring around the bright bipolar region presents a low expansion velocity and could be associated to ejection in the AGB-PN transition phase, although its nature remains unclear. The chemical abundances of the central region are derived, showing that M 2-48 is a Type I planetary nebula (PN)

    Detection of a multi-shell planetary nebula around the hot subdwarf O-type star 2MASS J19310888+4324577

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    (Abridged) The origin of hot subdwarf O-type stars (sdOs) remains unclear since their discovery in 1947. Among others, a post-Asymptotic Giant Branch (post-AGB) origin is possible for a fraction of sdOs. We are involved in a comprehensive ongoing study to search for and to analyze planetary nebulae (PNe) around sdOs with the aim of establishing the fraction and properties of sdOs with a post-AGB origin. We use deep Halpha and [OIII] images of sdOs to detect nebular emission and intermediate resolution, long-slit optical spectroscopy of the detected nebulae and their sdO central stars. These data are complemented with other observations for further analysis of the detected nebulae. We report the detection of an extremely faint, complex PN around 2MASS J19310888+4324577 (2M1931+4324), a star classified as sdO in a binary system. The PN shows a bipolar and an elliptical shell, whose major axes are oriented perpendicular to each other, and high-excitation structures outside the two shells. WISE archive images show faint, extended emission at 12 and 22 microns in the inner nebular regions. The internal nebular kinematics is consistent with a bipolar and a cylindrical/ellipsoidal shell, in both cases with the main axis mainly perpendicular to the line of sight. The nebular spectrum only exhibits Halpha, Hbeta and [OIII]4959,5007 emission lines, but suggests a very low-excitation ([OIII]/Hbeta = 1.5), in strong contrast with the absence of low-excitation emission lines. The spectrum of 2M1931+4324 presents narrow, ionized helium absorptions that confirm the previous sdO classification and suggest an effective temperature >= 60000 K. The binary nature of 2M1931+4324, its association with a complex PN, and several properties of the system provide strong support for the idea that binary central stars are a crucial ingredient in the formation of complex PNe.Comment: 8 pages, 7 figures, accepted in Astronomy and Astrophysic

    Laminosioptes cysticola and Gallibacterium anatis infections in a lymphoma diseased chicken hen with a cystic right oviduct

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    A domestic hen showing infraorbital swelling was presented for a routine classroom demonstration of avian diagnostics. At necropsy, tiny whitish caseo-calcareous nodules were found in the subcutaneous tissues of the carcass, produced by the subcutaneous fowl mite, Laminosioptes cysticola. Gallibacterium anatis biovar haemolytica was isolated from the infraorbital sinus, it containing a caseous exudate. During necropsy, a conspicuous cyst was found in the abdominal cavity. Microscopic examination of the internal lining of the cyst revealed a single cuboidal to columnar, ciliated epithelium, leading to a diagnosis of oviductal cyst. Also, the microscopic examination of the heart, lung, liver and kidney reveal a multifocal infiltration of lymphoma cells. It appears the first case of simultaneous presentation of these conditions from a single chicken

    Modified cyclodextrin type and dehydration methods exert a significant effect on the antimicrobial activity of encapsulated carvacrol and thymol

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    BACKGROUND The antimicrobial activity of essential oils and their constituents has led to increasing interest in using them as natural preservative agents. However, their high sensitivity to light and oxygen, their volatility and their low aqueous solubility are all obstacles to their application in the food, cosmetic or pharmaceutical industries. Encapsulation in cyclodextrins (CDs) is a solution for the application of such essential oils. RESULTS The complexation of carvacrol and thymol with hydroxypropyl (HP)‐α‐, HP‐β‐ and HP‐γ‐CD, the behavior of the solid complexes prepared by freeze‐drying and spray‐drying methods and the antibacterial activity of solid complexes were studied. Kc values of HP‐α‐ and HP‐γ‐CD complexes with carvacrol (118.4 and 365.7 L mol−1) and thymol (112.5 and 239.7 L mol −1) were far lower than those observed for HP‐β‐CD complexes with carvacrol (2268.2 L mol −1) and thymol (881.6 L mol −1). The lower stability of HP‐α‐ and HP‐γ‐CD complexes increased the release of compounds, thereby affecting the antimicrobial activity of carvacrol and thymol to a lesser extent than complexation with HP‐β‐CD, normally used in the encapsulation of carvacrol and thymol. HP‐β‐CD encapsulation of carvacrol and thymol markedly reduced their antimicrobial activity. The freeze‐drying method barely affected the antimicrobial activity of carvacrol and thymol after encapsulation, while spray drying could be considered for the production of solid complexes in combination with the appropriate CD. CONCLUSIONS It was thus demonstrated that HP‐α‐ and HP‐γ‐CD are very suitable alternatives for the encapsulation of carvacrol and thymol with the purpose of preserving their bacteriostatic and bactericidal activities

    Wormhole Cosmic Censorship

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    We analyze the properties of a Kerr-like wormhole supported by phantom matter, which is an exact solution of the Einstein-phantom field equations. It is shown that the solution has a naked ring singularity which is unreachable to null geodesics falling freely from the outside. Similarly to Roger Penrose's cosmic censorship, that states that all naked singularities in the Universe must be protected by event horizons, here we conjecture from our results that a naked singularity can also be fully protected by the intrinsic properties of a wormhole's throat

    Observational Study of the Multistructured Planetary Nebula NGC 7354

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    We present an observational study of the planetary nebula (PN) NGC 7354 consisting of narrowband Halpha and [NII]6584 imaging as well as low- and high-dispersion long-slit spectroscopy and VLA-D radio continuum. According to our imaging and spectroscopic data, NGC 7354 has four main structures: a quite round outer shell and an elliptical inner shell, a collection of low-excitation bright knots roughly concentrated on the equatorial region of the nebula, and two symmetrical jet-like features, not aligned either with the shells' axes, or with each other. We have obtained physical parameters like electron temperature and electron density as well as ionic and elemental abundances for these different structures. Electron temperature and electron density slightly vary throughout the nebula. The local extinction coefficient c_Hbeta shows an increasing gradient from south to north and a decreasing gradient from east to west consistent with the number of equatorial bright knots present in each direction. Abundance values show slight internal variations but most of them are within the estimated uncertainties. In general, abundance values are in good agreement with the ones expected for PNe. Radio continuum data are consistent with optically thin thermal emission. We have used the interactive three-dimensional modeling tool SHAPE to reproduce the observed morphokinematic structures in NGC 7354 with different geometrical components. Our SHAPE model is in very good agreement with our imaging and spectroscopic observations. Finally, after modeling NGC 7354 with SHAPE, we suggest a possible scenario for the formation of the nebula.Comment: Accepted for publication in AJ, 12 pages, 8 figure

    The physical structure of the point-symmetric and quadrupolar planetary nebula NGC 6309

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    We analyse the point-symmetric planetary nebula NGC 6309 in terms of its three-dimensional structure and of internal variations of the physical conditions to deduce the physical processes involved in its formation. We used VLA-D 3.6-cm continuum, ground-based, and HST-archive imaging as well as long slit high- and low-dispersion spectroscopy. The low-dispersion spectra indicate a high excitation nebula, with low to medium variations of its internal physical conditions. In the optical images, the point-symmetric knots show a lack of [NII] emission as compared with similar features previously known in other PNe. A rich internal structure of the central region is seen in the HST images, resembling a deformed torus. Long slit high-dispersion spectra reveal a complex kinematics in the central region. The spectral line profiles from the external regions of NGC 6309 indicate expanding lobes (~40 km/s) as those generally found in bipolar nebulae. Finally, we have found evidence for the presence of a faint halo, possibly related to the envelope of the AGB-star progenitor. Our data indicate that NGC 6309 is a quadrupolar nebula with two pairs of bipolar lobes whose axes are oriented PA=40 and PA=76. Equatorial and polar velocities for these two pairs of lobes are 29 and 86 km/s for the bipolar system at PA=40 and 25 and 75 km/s for the bipolar system at PA=76. There is also a central torus that is expanding at 25 km/s. Kinematical age for all these structures is around 3700 to 4000 yr. We conclude that NGC 6309 was formed by a set of well-collimated bipolar outflows (jets), which were ejected in the initial stages of its formation as a planetary nebula. These jets carved the bipolar lobes in the previous AGB wind and their remnants are now observed as the point-symmetric knots tracing the edges of the lobes.Comment: To be published in Astronomy & Astrophysics; 11 pages, 8 figures, 4 table

    Homecare physiotherapy in the iberian peninsula public health system

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    Objetivos - Conocer los principales servicios de fisioterapia domiciliaria que oferta el Sistema Sanitario Público para las personas mayores dependientes de la Península Ibérica (España y Portugal). Estrategia de búsqueda - Revisión bibliográfica actualizada y exhaustiva sobre los estudios previos; estancia de investigación en Hospitales, Centros de Salud y organismos financiados por la Administración Pública en ambos países; entrevistas en profundidad a informantes estratégicos. Síntesis de los resultados - Se describe la situación de la fisioterapia domiciliaria en España, desde el año 1987 hasta agosto de 2008. Se detecta que en Portugal la fisioterapia domiciliaria está recogida en la cartera de servicios de atención primaria (Decreto-Ley no 28/2008, del 22 de febrero). Conclusiones - Existen pocas investigaciones a nivel de la Península que ofrezcan datos objetivos basados en la evidencia científica sobre la efectividad de estos servicios de fisioterapia, la satisfacción del usuario y las repercusiones que producen con respecto a otros tratamientos; sin embargo, estos estudios son necesarios para la evaluación de las políticas sanitarias, la distribución adecuada de recursos, la revisión de los programas, la metodología de actuación, etc.ABSTRACT - Objectives: To become acquainted with the principal homecare physiotherapy services that are offered by the Public Health System for dependent elderly patients in the Iberian Peninsula (Spain and Portugal). Methods: A thorough and updated review of the literature regarding previous studies, research stays in Hospitals, Primary Health Care Centers and Public Health institutions in both countries financed by the Public Health Administration; in-depth interviews with specific informants. Results: The situation of homecare physiotherapy in Spain from the year 1987 to the August 2008 is described. In Portugal, these services are established within the services regulated by Primary Health Care (Decree-Law no. 28/2008, of February 22). Conclusions: There are few studies in the Iberian Peninsula that offer scientific evidence-based information on the effectiveness of these physiotherapy services, user satisfaction and the effect they have in relation to other treatments. However, these studies are needed in order to evaluate the current health legislation, appropriate distribution of resources, to review the clinical programs, clinical action methodologies, etc.info:eu-repo/semantics/publishedVersio
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