413 research outputs found
SALT observations of southern post-novae
We report on recent optical observations of the stellar and the nebular
remnants of 22 southern post-novae. In this study, for each of our targets, we
obtained and analysed long-slit spectra in the spectral range 3500-6600 A and
in H+NII narrow-band images. The changes in the emission lines'
equivalent widths with the time since the outburst agree with earlier published
results of other authors. We estimated an average value =2.37 for the
exponent of the power law fitted to the post-novae continua. Our observations
clearly show the two-component structure of the V842 Cen expanding nebulae,
owing to the different velocities of the ejected matter. We discovered an
expanding shell around V382 Vel with an outer diameter of about 12 arcsec.Comment: 24 pages, 19 figures, A&A accepte
Contemporary neurotrophic factor research: towards a more human paradigm
The nerve growth factor (NGF) has been discovered by Rita Levi-Montalcini in the early 1950s. This paradigmic cell growth factor has gradually attracted the attention of many investigators from all over the world. In the very beginning, experimental research prevailed taking into consideration the still rather fundamental approach to the possible role of NGF and the subsequently discovered other neurotrophic factors in the living organism. Later on, an increasingly stable orientation of the scientific community towards the human beings, including a more outlined clinical research policy, has been emerging.Biomedical Reviews 1999; 10: 107-110
Adipobiology: a scientometric view to its increasing significance
Recent seminal papers in adipose tissue launched a new integrating discipline designated "adipobiology". Here we provide a retrospective problem-oriented search in MEDLINE and EMBASE databases available through OVID in 1980-2005; available papers published in 2006/2007 were also pursued. The following terms were used as key words during the information retrieval: adipose tissue, adipokine(s), adipocytokine(s), adipsin, adiponectin, and leptin. Although these adipocentric publications are easy to find in Internet browsers worldwide, we detected the term of "adipobiology" in a couple of biomedical databases only. Obviously, much remains to be done in order to attract the efforts of a rapidly increasing scientific community to the establishment and successful institutionalization of this discipline facing the requirements of knowledge-based, information-driven society of the new millennium. From a scientometric point of view, the present Dance Round describes some aspects of the dynamic growth of the world publication output in basic, translational and clinical adipobiology as compared with some other recently emerged topics, and traces some elements of its future development.Biomedical Reviews 2006; 17: 111-116
Modelling parallel database management systems for performance prediction
Abstract unavailable please refer to PD
Selecting asteroids for a targeted spectroscopic survey
Asteroid spectroscopy reflects surface mineralogy. There are few thousand
asteroids whose surfaces have been observed spectrally. Determining the surface
properties of those objects is important for many practical and scientific
applications, such as for example developing impact deflection strategies or
studying history and evolution of the Solar System and planet formation.
The aim of this study is to develop a pre-selection method that can be
utilized in searching for asteroids of any taxonomic complex. The method could
then be utilized im multiple applications such as searching for the missing
V-types or looking for primitive asteroids.
We used the Bayes Naive Classifier combined with observations obtained in the
course of the Sloan Digital Sky Survey and the Wide-field Infrared Survey
Explorer surveys as well as a database of asteroid phase curves for asteroids
with known taxonomic type. Using the new classification method we have selected
a number of possible V-type candidates. Some of the candidates were than
spectrally observed at the Nordic Optical Telescope and South African Large
Telescope.
We have developed and tested the new pre-selection method. We found three
asteroids in the mid/outer Main Belt that are likely of differentiated type.
Near-Infrared are still required to confirm this discovery. Similarly to other
studies we found that V-type candidates cluster around the Vesta family and are
rare in the mid/oter Main Belt.
The new method shows that even largely explored large databases combined
together could still be further exploited in for example solving the missing
dunite problem.Comment: accepted to A
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