5,146 research outputs found
Cognición y Representación: Persiguiendo un Sueño
La verdadera equidad educacional no se logra con sólo abrir los colegios a todos los niños, sino ofreciéndoles oportunidades de éxito escolar a través del cultivo de la diversidad cognoscitiva, considerando el rol de la cultura y de la escuela en este proceso. La mente es un logro cultural cuya conformación está influida significativamente por el tipo de experiencias vivenciadas por una persona en el transcurso de su vida. Las formas de representación que se usan como sistemas de
símbolos para representar lo que se piensa influyen en los procesos de pensamiento y en los productos de éste, desarrollan diferentes destrezas cognoscitivas e inciden en lo que uno es capaz de ver y de representar. En el
trabajo docente, ellas pueden combinarse para enriquecer el conjunto de recursos ofrecidos a los alumnos a modo de que entiendan ideas importantes, útiles, hermosas y poderosas; que piensen analítica y críticamente; que especulen imaginativamente para ver conexiones en las ideas y que usen lo que saben para mejorar sus vidas y contribuir a la cultura
First L-band Interferometric Observations of a Young Stellar Object: Probing the Circumstellar Environment of MWC 419
We present spatially-resolved K- and L-band spectra (at spectral resolution R
= 230 and R = 60, respectively) of MWC 419, a Herbig Ae/Be star. The data were
obtained simultaneously with a new configuration of the 85-m baseline Keck
Interferometer. Our observations are sensitive to the radial distribution of
temperature in the inner region of the disk of MWC 419. We fit the visibility
data with both simple geometric and more physical disk models. The geometric
models (uniform disk and Gaussian) show that the apparent size increases
linearly with wavelength in the 2-4 microns wavelength region, suggesting that
the disk is extended with a temperature gradient. A model having a power-law
temperature gradient with radius simultaneously fits our interferometric
measurements and the spectral energy distribution data from the literature. The
slope of the power-law is close to that expected from an optically thick disk.
Our spectrally dispersed interferometric measurements include the Br gamma
emission line. The measured disk size at and around Br gamma suggests that
emitting hydrogen gas is located inside (or within the inner regions) of the
dust disk.Comment: Accepted for publication in Ap
A Full Waveform Test of the Southern California Velocity Model by the Reciprocity Method
A Cautionary Note about the Use of Estimated Homicide Data for Cross-National Research
A major development in criminology in recent years has been the efforts by the World Health Organization to provide reasonably reliable estimates of homicide rates for a large number of nations. In some instances, these estimates entail adjustments of the records on homicide from vital statistics or criminal justice sources submitted by participating nations. These adjustments are designed to deal with underreporting and detected anomalies. In other instances, the estimates are generated by regression modeling. The purpose of this research note is to raise awareness among the community of homicide researchers of the nature of the WHO homicide estimates and to offer caution about their appropriate use for cross-national research
High Resolution K-band Spectroscopy of MWC 480 and V1331 Cyg
We present high resolution (R=25,000-35,000) K-band spectroscopy of two young
stars, MWC 480 and V1331 Cyg. Earlier spectrally dispersed (R=230)
interferometric observations of MWC 480 indicated the presence of an excess
continuum emission interior to the dust sublimation radius, with a spectral
shape that was interpreted as evidence for hot water emission from the inner
disk of MWC 480. Our spectrum of V1331 Cyg reveals strong emission from CO and
hot water vapor, likely arising in a circumstellar disk. In comparison, our
spectrum of MWC 480 appears mostly featureless. We discuss possible ways in
which strong water emission from MWC 480 might go undetected in our data. If
strong water emission is in fact absent from the inner disk, as our data
suggest, the continuum excess interior to the dust sublimation radius that is
detected in the interferometric data must have another origin. We discuss
possible physical origins for the continuum excess.Comment: 29 pages, 5 figures, to appear in Ap
- …