Central Stars of Planetary Nebulae: New spectral classifications and catalogue

Context. There are more than 3000 true and probable known Galactic Planetary Nebulae (PNe), but only for 13% of them there is central star spectroscopic information available. Aims. To contribute to the knowledge of central stars of planetary nebulae and star evolution. Methods. We undertook a spectroscopic survey of central stars of PNe in low resolution and compiled a large list of central stars for which information was dispersed in the literature. Results. We complete a catalogue of 492 true and probable CSPN and we provide a preliminary spectral classification for 45 central star of PNe, This made it possible to update the proportion of CSPN with atmosphere poor in hydrogen with regard to the whole in at least 30% and contribute with statistical information that allow to infer the origin of H-poor stars.Comment: 19 pages, 1 figure, accepted to be published in A&A (October 24, 2010

PT Symmetric, Hermitian and P-Self-Adjoint Operators Related to Potentials in PT Quantum Mechanics

In the recent years a generalization $H=p^2 +x^2(ix)^\epsilon$ of the harmonic oscillator using a complex deformation was investigated, where \epsilon\ is a real parameter. Here, we will consider the most simple case: \epsilon even and x real. We will give a complete characterization of three different classes of operators associated with the differential expression H: The class of all self-adjoint (Hermitian) operators, the class of all PT symmetric operators and the class of all P-self-adjoint operators. Surprisingly, some of the PT symmetric operators associated to this expression have no resolvent set

A mixed methods investigation into the use of non-technical skills by community and hospital pharmacists.

Background: Non-technical skills refer to the social and cognitive factors that may influence efficient and safe job performance. Non-technical skills are an important element of patient safety in a variety of health care disciplines, including surgery, anesthesia and nursing. However, the use of non-technical skills in pharmacy practice has not yet been fully assessed. Objective: To examine attitudes toward, and use of, non-technical skills by pharmacy personnel. Methods: A mixed methods approach was used: An attitude survey explored pharmacy personnel attitudes towards non-technical skills and inter-professional collaboration, with community and hospital pharmacy staff (. n = 62). Qualitative interviews were then conducted using the critical incident technique, with community pharmacists (. n = 11). Results: The survey results demonstrated differences in the opinions of community and hospital pharmacists on three non-technical skill constructs: team structure, mutual support, and situation monitoring, with community pharmacists reporting significantly more positive attitudes about all three constructs. Both groups reported low levels of collaboration with primary care physicians. The interviews identified five non-technical skills as key elements of successful pharmacist performance from the interview transcripts: teamwork; leadership; task management; situation awareness; decision-making. Conclusion: The survey and interviews identified the non-technical skills that are important to pharmacists. This represents the first step towards the development of a behavioral rating system for training purposes that could potentially improve the non-technical skills of pharmacists and enhance patient safety

Photometric and spectroscopic variations of the Be star HD 112999

Be objects are stars of B spectral type showing lines of the Balmer series in emission. The presence of these lines is attributed to the existence of an extended envelope, disk type, around them. Some stars are observed in both the Be and normal B-type spectroscopic states and they are known as transient Be stars. In this paper we show the analysis carried out on a new possible transient Be star, labelled HD 112999, using spectroscopic optical observations and photometric data.Comment: 10 pages, 5 figures, accepted for publication in IBV

Central stars of planetary nebulae : II. New OB-type and emission-line stars

Context. There are more than 3000 confirmed and probably known Galactic planetary nebulae (PNe), but central star spectroscopic information is available for only 13% of them. Aims. We have undertaken a spectroscopic survey of the central stars in PNe to identify their spectral types. Methods. We performed spectroscopic observations at low resolution with the 2-m telescope at CASLEO, Argentina. Results. We present the spectra of 46 central stars of PNe, most of them are OB-type and emission-line stars.Facultad de Ciencias Astronómicas y GeofísicasInstituto de Astrofísica de La Plat

Evaluation of Aposphaeria amaranthi as a Bioherbicide for Pigweed (Amaranthus Spp.)

Studies were conducted to determine the potential of the fungus, Aposphaeria amaranth!, as a bioherbicide for pigweeds (Amaranthus spp.). Experiments to establish the environmental parameters necessary for control of tumble pigweed (A. albus) demonstrated that an 8-hr dew period was sufficient for control of seedlings with four to six leaves, and that temperatures ranging from 20 to 28 C were conducive for disease development. Conidial concentrations as lowas 1x 10s conidia per ml also were sufficient for plant mortality. Host range tests demonstrated pathogenicity of A. amaranthi to several other species of Amaranthus, including biotypes resistant to triazine herbicides. Disease on redroot pigweed (A. retroflexus) was enhanced by incorporation of surfactants into inoculum suspensions. Field tests conducted in 1990 resulted in 73% control of redroot pigweed and 99% control of tumble pigweed. These results suggest that Aposphaeria amaranthi has potential as a bioherbicide for controlling pigweeds

Central stars of planetary nebulae : II. New OB-type and emission-line stars

Context. There are more than 3000 confirmed and probably known Galactic planetary nebulae (PNe), but central star spectroscopic information is available for only 13% of them. Aims. We have undertaken a spectroscopic survey of the central stars in PNe to identify their spectral types. Methods. We performed spectroscopic observations at low resolution with the 2-m telescope at CASLEO, Argentina. Results. We present the spectra of 46 central stars of PNe, most of them are OB-type and emission-line stars.Facultad de Ciencias Astronómicas y GeofísicasInstituto de Astrofísica de La Plat

Central stars of planetary nebulae: New spectral classifications and catalogue

Context. There are more than 3000 confirmed and probable known Galactic planetary nebulae (PNe), but central star spectroscopic information is available for only 13% of them. Aims. We undertook a spectroscopic survey of central stars of PNe at low resolution and compiled a large list of central stars for which information was dispersed in the literature. Methods. We observed 45 PNs using the 2.15 m telescope at Casleo, Argentina. Results. We present a catalogue of 492 confirmed and probable CSPN and provide a preliminary spectral classification for 45 central star of PNe. This revises previous values of the proportion of CSPN with atmospheres poor in hydrogen in at least 30% of cases and provide statistical information that allows us to infer the origin of H-poor stars.Instituto de Astrofísica de La PlataFacultad de Ciencias Astronómicas y Geofísica

The Spatial Orientation of Planetary Nebulae Within the Milky Way

We analyze the spatial orientation of a homogenous sample of 440 elongated Planetary Nebulae (PNe) in order to determine the orientation of their apparent major axis respect to the Milky Way plane. We present some important geometrical and statistical considerations that have been overlooked by the previous works on the subject. The global distribution of galactic position angles (GPA) of PNe is quantitatively not very different from a random distribution of orientations in the Galaxy. Nevertheless we find that there is at least one region on the sky, toward the galactic center, where a weak correlation may exist between the orientation of the major axis of some PNe and the Galactic equator, with an excess of axes with GPA$\sim 100^{\circ}$. Therefore, we confirm that ``extrinsic'' phenomena (i.e., global galactic magnetic fields, shell compression from motion relative to the Interstellar Medium) do not determine the morphology of PNe on most of the sky, with a possible exception towards the galactic center.Comment: 37 pages and 8 figures. Accepted for publication in PAS