359 research outputs found
Mexico : human capital effects on wages and productivity
The authors follow the Hellerstein, Neumark, and Troske (1999) framework to estimate marginal productivity differentials and compare them with estimated relative wages. The analysis provides evidence on productivity and nonproductivity-based determinations of wages. Special emphasis is given to the effects of human capital variables, such as education, experience, and training on wages and productivity differentials. Higher education yields higher productivity. However, highly educated workers earn less than their productivity differentials would predict. On average, highly educated workers are unable to fully appropriate their productivity gains of education through wages. On the other hand, workers with more experience are more productive in the same proportion that they earn more in medium and large firms, meaning they are fully compensated for their higher productivity. Finally, workers in micro and small firms are paid more than what their productivity would merit. Training benefits firms and employees since it significantly increases workers'productivity and their earnings.Primary Education,Economic Theory&Research,Access&Equity in Basic Education,Labor Markets,Tertiary Education
Pillars of creation amongst destruction: Star formation in molecular clouds near R136 in 30 Doradus
New sensitive CO(2-1) observations of the 30 Doradus region in the Large
Magellanic Cloud are presented. We identify a chain of three newly discovered
molecular clouds we name KN1, KN2 and KN3 lying within 2--14 pc in projection
from the young massive cluster R136 in 30 Doradus. Excited H 2.12m
emission is spatially coincident with the molecular clouds, but ionized
Br emission is not. We interpret these observations as the tails of
pillar-like structures whose ionized heads are pointing towards R136. Based on
infrared photometry, we identify a new generation of stars forming within this
structure.Comment: Accepted for publication in ApJ (includes 13 pages, 8 figures). For
higher resolution figures please see
http://www.das.uchile.cl/~vkalari/staplervk.pd
Massive young stellar objects in the N66/NGC346 region of the SMC
We present HK spectra of three sources located in the N66 region of the Small
Magellanic Cloud. The sources display prominent stellar Br Gamma and extended
H2 emission, and exhibit infrared excesses at lambda > 2 micron. Based on their
spectral features, and photometric spectral energy distributions, we suggest
that these sources are massive young stellar objects (mYSOs). The findings are
interpreted as evidence of on-going high mass star formation in N66.Comment: Accepted for publication on Astronomy and Astrophysics Journal,
acceptance date 21/03/2018 (includes 12 pages, 5 figures
The genus Thelypteris (Thelypteridaceae, Polypodiopsida) in the state of Mato Grosso, Brazil, II. Subgenera Amauropelta (Kunze) A.R. Sm., Cyclosorus (Link) C.V. Morton and Steiropteris (C. Chr.) K. Iwats.
The family Thelypteridaceae presents considerable species richness throughout the hillside forests and coastal plains of Brazil, as well as in the forests of its southern plateau. This study was based on material collected in 24 trips to various regions within the state of Mato Grosso, as well as material deposited in the principal Brazilian herbaria and in other herbaria. The genus Thelypteris, represented in this study by the subgenera Amauropelta (Kunze) A.R. Sm., Cyclosorus (Link) Morton and Steiropteris (C. Chr.) K. Iwats., comprises 11 species in Mato Grosso and surrounding regions. Keys for identification, descriptions and references to illustrations of diagnostic characters are presented.Fil: Ponce, Marta Monica. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Botánica Darwinion (i); Argentina;Fil: Kieling-Rubio, Maria Angélica. Universidade FEEVALE; Brasil;Fil: Windisch, Paulo Günter. Universidade Federal Do Rio Grande Do Sul. Programa de Pós-Graduação em Botânica; Brasil
The Spitzer Survey of the Small Magellanic Cloud: Discovery of Embedded Protostars in the HII Region NGC 346
We use Spitzer Space Telescope observations from the Spitzer Survey of the
Small Magellanic Cloud (S3MC) to study the young stellar content of N66, the
largest and brightest HII region in the SMC. In addition to large numbers of
normal stars, we detect a significant population of bright, red infrared
sources that we identify as likely to be young stellar objects (YSOs). We use
spectral energy distribution (SED) fits to classify objects as ordinary (main
sequence or red giant) stars, asymptotic giant branch stars, background
galaxies, and YSOs. This represents the first large-scale attempt at blind
source classification based on Spitzer SEDs in another galaxy. We firmly
identify at least 61 YSOs, with another 50 probable YSOs; only one embedded
protostar in the SMC was reported in the literature prior to the S3MC. We
present color selection criteria that can be used to identify a relatively
clean sample of YSOs with IRAC photometry. Our fitted SEDs indicate that the
infrared-bright YSOs in N66 have stellar masses ranging from 2 Msun to 17 Msun,
and that approximately half of the objects are Stage II protostars, with the
remaining YSOs roughly evenly divided between Stage I and Stage III sources. We
find evidence for primordial mass segregation in the HII region, with the most
massive YSOs being preferentially closer to the center than lower-mass objects.
Despite the low metallicity and dust content of the SMC, the observable
properties of the YSOs appear consistent with those in the Milky Way. Although
the YSOs are heavily concentrated within the optically bright central region of
N66, there is ongoing star formation throughout the complex and we place a
lower limit on the star formation rate of 3.2 x 10^-3 Msun/yr over the last ~1
Myr.Comment: 13 pages, 5 figures (3 in color), 2 tables. Accepted for publication
in Ap
Cómo elegir un buen sustrato para las macetas
La elección y uso correcto de un sustrato es clave para la producción de plantas de alta calidad. Especialistas del Instituto de Floricultura del INTA brindan recomendaciones a la hora de elegirlos de acuerdo con su función, dónde será utilizado y los requerimientos tanto físicos como químicos.Instituto de FloriculturaFil: Rubio, Esteban Julian. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Floricultura; ArgentinaFil: Karlanian, Mónica N. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Floricultura; Argentin
Mecanismos moleculares involucrados en el control de la expresión génica y el desarrollo tumoral
Además de diversos procesos fisiológicos que controlan el desarrollo tumoral, existen mecanismos moleculares por los cuales se determina el destino de una célula. Estos mecanismos permiten la proliferación de las células que el organismo detecta como sanas o normales o bien, ante daños genómicos que no pudieron ser reparados y el riesgo de expansión de estos errores, las células son eliminadas por apoptosis o entran en estado de senescencia replicativa. El correcto funcionamiento de estos mecanismos es el que garantiza el estado de salud del individuo.Fil: Costas, Monica Alejandra. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Oficina de Coordinacion Administrativa Houssay. Instituto de Investigaciones Medicas; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Médicas; ArgentinaFil: Micenmacher, Sabrina Mariel. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Oficina de Coordinacion Administrativa Houssay. Instituto de Investigaciones Medicas; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Médicas; ArgentinaFil: Rubio, Maria Fernanda. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Oficina de Coordinacion Administrativa Houssay. Instituto de Investigaciones Medicas; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Médicas; ArgentinaFil: Fernandez Larrosa, Pablo Nicolas. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Oficina de Coordinacion Administrativa Houssay. Instituto de Investigaciones Medicas; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Médicas; Argentin
A Workflow for Estimating and Visualising Excess Mortality During the COVID-19 Pandemic
COVID-19 related deaths estimates underestimate the pandemic burden on mortality because they suffer from completeness and accuracy issues. Excess mortality is a popular alternative, as it compares the observed number of deaths versus the number that would be expected if the pandemic did not occur. The expected number of deaths depends on population trends, temperature, and spatio-temporal patterns. In addition to this, high geographical resolution is required to examine within country trends and the effectiveness of the different public health policies. In this tutorial, we propose a workflow using R for estimating and visualising excess mortality at high geographical resolution. We show a case study estimating excess deaths during 2020 in Italy. The proposed workflow is fast to implement and allows for combining different models and presenting aggregated results based on factors such as age, sex, and spatial location. This makes it a particularly powerful and appealing workflow for online monitoring of the pandemic burden and timely policy making
Near-infrared surface photometry of early-type galaxies
CCD infrared (JHKs) photometry was performed on a sample of 10 elliptical and 2 lenticular galaxies. Isophotal parameters, brightness profiles, integrated colors and color gradients arepresented. Color gradients found arevery weak, showing bluer colors towards the outer regions. The colors of the sample galaxies are compatible with stellar populations like those found in metal-rich clusters of the Galaxy; objects NGC7192, NGC7562 and NGC7619 are compatible with less metal-rich populations. The brightness profile of most galaxies is well described by the r1/4 law. The profiles of NGC1600 and NGC720 are described by Sérsic’s law with n ∼ 1.5 andn ∼ 1.8 respectively. The infrared effective radius of the objects studied is typically one half of its counterpart in the B band, which can be an indication that the stellar population that dominates the infrared emission is more concentrated in the central regions. Weshow that the sample satisfies the Fundamental Plane relation of elliptical galaxies in the infrared, with an rms scatter of 0.20 for J and H and 0.23 for Ks
Autophagy. A strategy for cell survival
La autofagia es un proceso de reciclado de partes de la célula. Como se describe en esta revisión, ocurre naturalmente preservando a las células de la acumulación de toxinas, moléculas y organelas dañadas y además permite los procesos de desarrollo y diferenciación de los tejidos. En el transcurso de la autofagia, el procesamiento de los sustratos a reciclar genera ATP, lo que constituye una fuente alternativa de energía en situaciones de estrés. En este sentido, bajo condiciones hostiles como hipoxia o falta de nutrientes, el proceso puede dispararse de modo exacerbado llevando a la muerte celular. Algunas alteraciones en su funcionamiento pueden involucrar el desarrollo de diversas patologías, tales como el daño hepático, el cáncer y las enfermedades neurodegenerativas.Autophagy is a process of recycling parts of the cell. As described in this review, it occurs naturally in order to preserve cells from the accumulation of toxins, damaged molecules and organelles, and to allow processes of tissue development and differentiation. In the course of autophagy, the processing of the substrates to be recycled generates ATP, thus providing an alternative source of energy in stress situations. In this sense, under hostile conditions such as hypoxia or lack of nutrients, the autophagy process can be exacerbated leading to cell death. Some alterations in its functioning may involve the development of various pathologies, including liver damage, cancer and neurodegenerative diseases.Fil: Costas, Monica Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Médicas. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Médicas; ArgentinaFil: Rubio, Maria Fernanda. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Médicas. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Médicas; Argentin
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