An analysis of textbooks in problems of democracy

Thesis (M.A.)--Boston University, 1945. This item was digitized by the Internet Archive

New giant H II regions in the southern sky

We present results of a search for giant H II regions in southern galaxies. Using high-resolution spectra, obtained with the Magellan Inamori Kyocera Echelle (MIKE) at the Las Campanas Magellan II telescope, we were able to resolve the emission-line profiles and determine the intrinsic velocity dispersion of the ionized gas. Out of four observed regions, selected from previous CCD narrow-band photometry, we detected three H II regions showing supersonic velocity dispersion, characteristic of giant H II regions, and their location in diagnostic diagrams suggests that a powerful starburst is the source of ionization energy.Facultad de Ciencias Astronómicas y Geofísica

Giant H II regions in NGC 7479 and NGC 6070

We present new results from our search for giant H II regions in galaxies visible from the Southern hemisphere. In this work we study two galaxies: NGC 7479 and NGC 6070. Using high-resolution spectra, obtained with different instruments at Las Campanas Observatory, we are able to resolve the emission-line profile widths and determine the intrinsic velocity dispersion of the ionized gas. We detect profile widths corresponding to supersonic velocity dispersions in the six observed H II regions. We find that all of them show at least two distinct kinematical components: a relatively narrow feature (between 11 and 22 km s-1) and a broader (between 31 and 77 km s-1) component. Two of the regions show a complex narrow profile in all ion lines, which can be further split into two components with different radial velocities. Whereas the wing broadening of the overall profile can be fitted with a low-intensity broad component for almost all profiles, in one region it was better reproduced by two separate shell-like wings. We have analysed the impact that the presence of multiple components has on the location of the H II regions in the log (L)-log (σ) plane. Although the overall distribution confirms the presence of a regression, the precise location of the regions in the plane is strongly dependent on the components derived from the profile fitting.Facultad de Ciencias Astronómicas y Geofísica

Population dynamics of DENV-1 genotype V in Brazil is characterized by co-circulation and strain/lineage replacement

Following successive outbreaks of dengue fever caused predominantly by dengue virus (DENV) 2 and 3, DENV-1 is now the primary serotype circulating in Brazil. We sequenced and analyzed Brazilian DENV-1 genomes and found that all isolates belong to genotype V and are subdivided into three lineages, which were introduced during four different events. The first introduction occurred in 1984-85, the second in 1997-99, and the third and fourth occurred from 2004 to 2007. These events were associated with an increase in genetic diversity but not with positive selection. Moreover, a potential new recombinant strain derived from two distinct lineages was detected. We demonstrate that the dynamics of DENV-1 in Brazil is characterized by introduction, movement, local evolution, and lineage replacement. This study strengthens the relevance of genotype surveillance in order to identify, trace, and control virus populations circulating in Brazil and Latin America.Conselho Nacional de Pesquisas (Brazil) Conselho Nacional de Desenvolvimento Cientifico e TecnologicoFundação de Amparo à Pesquisa do Estado de Minas Gerai

Trabajos de investigación de contenido jurídico en titulaciones de perfil no jurídico dentro de las ciencias sociales

El presente trabajo analiza algunos aspectos de la dirección de trabajos de investigación de alumnos de titulaciones de perfil no jurídico por parte de profesores de Derecho. En particular, se aborda el problema de la descoordinación entre el objeto del trabajo de fin de grado y la formación del tutor o del estudiante, y se propone como posible solución la interdisciplinariedad

Spectroscopic study of the N159/N160 complex in the Large Magellanic Cloud

We present a spectroscopic study of the N159/N160 massive star-forming region south of 30 Doradus in the Large Magellanic Cloud, classifying a total of 189 stars in the field of the complex. Most of them belong to O and early B spectral classes; we have also found some uncommon and very interesting spectra, including members of the Onfp class, a Be PCygni star, and some possible multiple systems. Using spectral types as broad indicators of evolutionary stages, we considered the evolutionary status of the region as a whole. We infer that massive stars at different evolutionary stages are present throughout the region, favoring the idea of a common time for the origin of recent star formation in the N159/N160 complex as a whole, while sequential star formation at different rates is probably present in several subregions.Facultad de Ciencias Astronómicas y GeofísicasInstituto de Astrofísica de La Plat

High-resolution spectroscopy of the blue compact dwarf galaxy Haro 15 : I. Internal kinematics

Using echelle spectroscopy, obtained at Las Campanas Observatory, we present a detailed study of the internal kinematics of the nebular material in multiple knots of the blue compact dwarf galaxy Haro15. A detailed analysis of the complex emission-line profiles shows the presence of an underlying broad component in almost all knots, and the brightest star-forming region shows unmistakable signs for the presence of two distinct narrow kinematical components. We also study the information that our analysis provides regarding the motion of the individual knots in the Haro15 galaxy potential, confirming that they follow galactic rotation. Finally, we examine the relation between their velocity dispersion and luminosity, finding that almost all knots follow the relation for virialized systems. This holds for the strong narrow components identified in complex fits and for single profile fits, although the latter show a flatter slope. In agreement with previous findings, in this paper we show that the existence of multiple kinematical components among massive starbursts cannot be overlooked, as it has a noticeable effect on any subsequent analysis that relies on basic parameters.Facultad de Ciencias Astronómicas y Geofísica

The massive double-lined O-type binary HD 165052

We present a new optical spectroscopic study of the O-type binary HD 165052 based on high-and intermediate-resolution CCD observations. We re-investigated the spectral classification of the binary components, obtaining spectral types of O6.5 V and O7.5 V for the primary and secondary, respectively, finding that both stars display weak CIII λ5696 emission in their spectra. We also determined a radial-velocity orbit for HD 165052 with a period of 2.95510 ± 0.00001 d, and semi-amplitudes of 94.8 and 104.7 ± 0.5km s-1, resulting in a mass ratio Q = 0.9. From a comparison with previous radial-velocity determinations, we found evidence of apsidal motion in the system. Several signatures of wind-wind collision, such as phase-locked variability of the X-ray flux and the Struve-Sahade effect, are also considered. It was also found that the reddening in the region should be normal, in contrast with previous determinations.Facultad de Ciencias Astronómicas y Geofísica

Chemodynamics on BCDs

This work presents a brief summary of the analysis we are performing on the physical and chemical properties of the ionizing gas in star-forming regions belonging to 2 Blue Compact Dwarf galaxies (BCDs), using high resolution echelle spectra. Our aim is to perform a detailed study of the Chemodinamics on BCDs galaxies. To do that, we use the LMFIT (python tool), Pyneb (Luridiana et al. 2015) and our own code (Hagele et al. 2008). We deconvolve the emission-line profiles fitting several gaussians to the different kinematical components to be able to estimate the properties and the nature of the ionized gas. Our next step is to use our kinematical information to performe the chemical abundance analysis and to infer the physical properties of the gas (the chemodynamical study) by using the metodology published in Hagele et al. (2012).Fil: Campuzano Castro, Federico. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Astrofísica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas. Instituto de Astrofísica La Plata; ArgentinaFil: Hägele, Guillermo Federico. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Astrofísica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas. Instituto de Astrofísica La Plata; ArgentinaFil: Bosch, Guillermo Luis. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Astrofísica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas. Instituto de Astrofísica La Plata; ArgentinaFil: Firpo, Verónica. Universidad de La Serena; ChileFil: Morrell, Nidia Irene. Las Campanas Observatory; ChileFil: Cardaci, Monica Viviana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Astrofísica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas. Instituto de Astrofísica La Plata; ArgentinaFirst Workshop on Chemical Abundances in Gaseous NebulaeCampos do JordaoBrasilUniversidade do Vale do Paraíb