259 research outputs found
Tumor de CĂ©lulas Gigantes del Primer Metacarpiano
Se presenta un caso de tumor de células gigantes que afecta al primer metacarpiano.
El tratamiento consistiĂł en la resecciĂłn en bloque del metacarpiano y su sustituciĂłn
por injerto cortico-esponjoso de cresta ilĂaca.A case of giant cell tumor affecting the first metacarpal bone was presented.
Treatment consisted of block resection of the metacarpal and its substitution
by porous cortical bone graft from the iliac crest
Depth of focus increase by multiplexing programmable diffractive lenses
A combination of several diffractive lenses written onto a single programmable liquid crystal display (LCD) is proposed for increasing the Depth of Focus (DOF) of the imaging system as a whole. The lenses are spatially multiplexed in a random scheme onto the LCD. The axial irradiance distribution produced by each lens overlaps with the next one producing an extended focal depth. To compare the image quality of the multiplexed lenses, the Modulation Transfer Function (MTF) is calculated. Finally we obtain the experimental Point Spread Functions (PSF) for these multiplexed lenses and experimental results in which an extended object is illuminated under spatially incoherent monochromatic light. We compare the images obtained in the focal plane and in some defocused planes with the single lens and with three multiplexed lenses. The experimental results confirm that the multiplexed lenses produce a high increase in the depth of focus.Fil: Iemmi, Claudio Cesar. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de FĂsica; Argentina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas; ArgentinaFil: Campos, Juan. Universitat Autonoma de Barcelona; EspañaFil: Escalera, J. C.. Universitat Autonoma de Barcelona; EspañaFil: LĂłpez Coronado, O. Universitat Autonoma de Barcelona; EspañaFil: Gimeno, R.. Universitat Autonoma de Barcelona; EspañaFil: Yzuel, MarĂa J.. Universitat Autonoma de Barcelona; Españ
Substructure in the Coma Cluster: Giants vs Dwarfs
The processes that form and shape galaxy clusters, such as infall, mergers
and dynamical relaxation, tend to generate distinguishable differences between
the distributions of a cluster's giant and dwarf galaxies. Thus the dynamics of
dwarf galaxies in a cluster can provide valuable insights into its dynamical
history. With this in mind, we look for differences between the spatial and
velocity distributions of giant (b18) galaxies in the Coma
cluster. Our redshift sample contains new measurements from the 2dF and WYFFOS
spectrographs, making it more complete at faint magnitudes than any previously
studied sample of Coma galaxies. It includes 745 cluster members - 452 giants
and 293 dwarfs. We find that the line-of-sight velocity distribution of the
giants is significantly non-Gaussian, but not that for the dwarfs. A battery of
statistical tests of both the spatial and localised velocity distributions of
the galaxies in our sample finds no strong evidence for differences between the
giant and dwarf populations. These results rule out the cluster as a whole
having moved significantly towards equipartition, and they are consistent with
the cluster having formed via mergers between dynamically-relaxed subclusters.Comment: 23 pages, 6 figures, to appear in Ap
High spatial resolution optical imaging of the multiple T Tauri system LkH{\alpha} 262/LkH{\alpha} 263
We report high spatial resolution i' band imaging of the multiple T Tauri
system LkH 262/LkH 263 obtained during the first commissioning
period of the Adaptive Optics Lucky Imager (AOLI) at the 4.2 m William Herschel
Telescope, using its Lucky Imaging mode. AOLI images have provided photometry
for each of the two components LkH 263 A and B (0.41 arcsec separation)
and marginal evidence for an unresolved binary or a disc in LkH 262.
The AOLI data combined with previously available and newly obtained optical and
infrared imaging show that the three components of LkH 263 are
co-moving, that there is orbital motion in the AB pair, and, remarkably, that
LkH 262-263 is a common proper motion system with less than 1 mas/yr
relative motion. We argue that this is a likely five-component gravitationally
bounded system. According to BT-settl models the mass of each of the five
components is close to 0.4 M and the age is in the range 1-2 Myr. The
presence of discs in some of the components offers an interesting opportunity
to investigate the formation and evolution of discs in the early stages of
multiple very low-mass systems. In particular, we provide tentative evidence
that the disc in 263C could be coplanar with the orbit of 263AB.Comment: 11 pages, 7 figures, Accepted 2016 May
Improved expressions for performance parameters for complex filters
Improved expressions are given for the performance parameters for transverse and axial gains for complex pupil filters. These expressions can be used to predict the behavior of filters that give a small axial shift in the focal intensity maximum and also predict the changes in gain for different observation planes
New Optical Insights into the Mass Discrepancy of Galaxy Clusters: The Cases of A1689 and A2218
We analyze the internal structures of clusters A1689 and A2218 by applying a
recent development of the method of wavelet analysis, which uses the complete
information obtained from optical data, i.e. galaxy positions and redshifts. We
find that both clusters show the presence of structures superimposed along the
line of sight with different mean redshifts and smaller velocity dispersions
than that of the system as a whole, suggesting that the clusters could be cases
of the on-going merging of clumps. In the case of A2218 we find an acceptable
agreement between our estimate of optical virial mass and X-ray and
gravitational lensing masses. On the contrary, in the case of A1689 we find
that our mass estimates are smaller than X-ray and gravitational lensing ones
at both small and large radii. In any case, at variance with earlier claims,
there is no evidence that X-ray mass estimates are underestimated.Comment: 8 pages, 2 eps figures, Use LaTeX2e, accepted by Astrophysical
Journal, in press November 1997, Vol.49
Structure detection in the D1 CFHTLS deep field using accurate photometric redshifts: a benchmark
We investigate structures in the D1 CFHTLS deep field in order to test the
method that will be applied to generate homogeneous samples of clusters and
groups of galaxies in order to constrain cosmology and detailed physics of
groups and clusters. Adaptive kernel technique is applied on galaxy catalogues.
This technique needs none of the usual a-priori assumptions (luminosity
function, density profile, colour of galaxies) made with other methods. Its
main drawback (decrease of efficiency with increasing background) is overcame
by the use of narrow slices in photometric redshift space. There are two main
concerns in structure detection. One is false detection and the second, the
evaluation of the selection function in particular if one wants "complete"
samples. We deal here with the first concern using random distributions. For
the second, comparison with detailed simulations is foreseen but we use here a
pragmatic approach with comparing our results to GalICS simulations to check
that our detection number is not totally at odds compared to cosmological
simulations. We use XMM-LSS survey and secured VVDS redshifts up to z~1 to
check individual detections. We show that our detection method is basically
capable to recover (in the regions in common) 100% of the C1 XMM-LSS X-ray
detections in the correct redshift range plus several other candidates.
Moreover when spectroscopic data are available, we confirm our detections, even
those without X-ray data.Comment: 14 pages, 22 additionnal jpeg figures, accepted in A&
Large Structures and Galaxy Evolution in COSMOS at z < 1.1
We present the first identification of large-scale structures (LSS) at z in the Cosmic Evolution Survey (COSMOS). The structures are identified
from adaptive smoothing of galaxy counts in the pseudo-3d space
(,z) using the COSMOS photometric redshift catalog. The
technique is tested on a simulation including galaxies distributed in model
clusters and a field galaxy population -- recovering structures on all scales
from 1 to 20\arcmin without {\it a priori} assumptions for the structure size
or density profile. Our procedure makes {\bf no} {\it a priori} selection on
galaxy spectral energy distribution (SED, for example the Red Sequence),
enabling an unbiased investigation of environmental effects on galaxy
evolution. The COSMOS photometric redshift catalog yields a sample of
galaxies with redshift accuracy, at z down to I mag. Using this sample of galaxies,
we identify 42 large-scale structures and clusters. abstract truncated for
astroph 25 line limit -- see preprintComment: 72 pages with 29 pages of figures, for cosmos apj suppl special issu
The orosomucoid 1 protein (α1 acid glycoprotein) is overexpressed in odontogenic myxoma
Odontogenic myxoma (OM) is a benign, but locally invasive, neoplasm occurring in the jaws. However, the molecules implicated in its development are unknown. OM as well as Dental Follicle (DF), an odontogenic tissue surrounding the enamel organ, is derived from ectomesenchymal/mesencyhmal elements. To identify some protein that could participate in the development of this neoplasm, total proteins from OM were
separated by two-dimensional electrophoresis and the profiles were compared with those obtained from DF, used
as a control
SĂndrome de Fiebre Severa con Trombocitopenia como Problema de Salud PĂșblica Emergente
La trombocitopenia, como la fiebre y la anemia, son signos que en todos los casos debe aclararse su etiologĂa, estos en su mayorĂa, suelen estar asociados a enfermedades infecciosas, especialmente tropicales y zoonĂłticas. La primera se presenta por falta de producciĂłn o por aumento en la destrucciĂłn de las plaquetas. Las plaquetas son cĂ©lulas extremadamente importantes para los organismos vertebrados, pues son ellas las que previenen e interrumpen las hemorragias, actuando en la formaciĂłn de coĂĄgulos y participando en la coagulaciĂłn sanguĂnea. En años pasados se ha descrito un sĂndrome, de etiologĂa viral, que recibe el nombre de SĂndrome de Trombocitopenia con Fiebre Severa (SFTS). El SĂndrome de Trombocitopenia con Fiebre Severa es una enfermedad infecciosa transmitida por garrapatas (arbovirus), con una alta tasa de letalidad
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