4,894 research outputs found
Genetic Characterization of Jaguars (Panthera onca) in Captivity in Zoological Parks of Colombia
The construction of the pedigree of captive jaguars (Panthera onca) in zoological parks of Colombia was done using the analysis of the Regional Studbook for Jaguars and DNA analysis of 9 microsatellites of 20 Jaguars (n=20). The assignments for paternities and maternities were done with for the program CERVUS and the relationship between animals were established with the KINSHIP program. The analysis of the Studbook was done with SPARKS and PM2000 software generating the following values: genetic diversity for the population (GD=0.7832), potential genetic diversity (GD=0.9113), genic value (GV=0.7846), mean coefficient of inbreeding (F=0.0179), and the Mean KINSHIP (MK) for each individual. The averages of the observed and expected heterozygosity were 0.687 and 0.684 respectively. Nevertheless, a wild jaguar sample of 156 individuals obtained in Colombia substantially showed a higher degree of gene diversity (H = 0.87) than the Colombian captive jaguar population. Thus, the captive jaguar population retained 78 % of the gene diversity of the Colombian wild jaguar population. With this study the pedigree of the captive population of jaguars was built in order to develop an ex situ conservation plan for the species in the Colombian zoological parks
Video Endoscopy for Laser Photoresection in Tracheobronchial Pathology: Some Considerations After 9 Years Experience With 2105 Treatments
Between 1984 and 1993 we performed 2105 laser treatments in 1210 patients: 52% of treatments were done for malignant pathology, 45% for benign tracheal stenoses and 3% were in a miscellaneous group. The procedure was carried out with a rigid bronchoscope under general anaesthesia. In patients with malignant tumors, it is a good palliative treatment—safe, well tolerated and with immediate results; it can be repeated as many times as needed with and is well accepted by the patient. In patients without tumors, this method avoids emergency tracheotomies. The long term results are now under evaluation
3D Photometric Cosmic Shear
Here we present a number of improvements to weak lensing 3D power spectrum
analysis, 3D cosmic shear, that uses the shape and redshift information of
every galaxy to constrain cosmological parameters. We show how photometric
redshift probability distributions for individual galaxies can be directly
included in this statistic with no averaging. We also include the Limber
approximation, considerably simplifying full 3D cosmic shear analysis, and we
investigate its range of applicability. Finally we show the relationship
between weak lensing tomography and the 3D cosmic shear field itself; the steps
connecting them being the Limber approximation, a harmonic-space transform and
a discretisation in wavenumber. Each method has its advantages: 3D cosmic shear
analysis allows straightforward inclusion of all relevant modes, thus ensuring
minimum error bars, and direct control of the range of physical wavenumbers
probed, to avoid the uncertain highly nonlinear regime. On the other hand,
tomography is more convenient for checking systematics through direct
investigation of the redshift dependence of the signal. Finally, for
tomography, we suggest that the angular modes probed should be
redshift-dependent, to recover some of the 3D advantages.Comment: Accepted to MNRAS. 15 pages, 7 figure
Fossil Groups Origins III. Characterization of the sample and observational properties of fossil systems
(Abridged) Fossil systems are group- or cluster-sized objects whose
luminosity is dominated by a very massive central galaxy. In the current cold
dark matter scenario, these objects formed hierarchically at an early epoch of
the Universe and then slowly evolved until present day. That is the reason why
they are called {\it fossils}. We started an extensive observational program to
characterize a sample of 34 fossil group candidates spanning a broad range of
physical properties. Deep band images were taken for each candidate and
optical spectroscopic observations were obtained for 1200 galaxies. This
new dataset was completed with SDSS DR7 archival data to obtain robust cluster
membership and global properties of each fossil group candidate. For each
system, we recomputed the magnitude gaps between the two brightest galaxies
() and the first and fourth ranked galaxies ()
within 0.5 . We consider fossil systems those with mag or mag within the errors. We find
that 15 candidates turned out to be fossil systems. Their observational
properties agree with those of non-fossil systems. Both follow the same
correlations, but fossils are always extreme cases. In particular, they host
the brightest central galaxies and the fraction of total galaxy light enclosed
in the central galaxy is larger in fossil than in non-fossil systems. Finally,
we confirm the existence of genuine fossil clusters. Combining our results with
others in the literature, we favor the merging scenario in which fossil systems
formed due to mergers of galaxies. The large magnitude gap is a
consequence of the extreme merger ratio within fossil systems and therefore it
is an evolutionary effect. Moreover, we suggest that at least one candidate in
our sample could represent a transitional fossil stage.Comment: 14 pages, 11 figures, accepted for publication in A&
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