18 research outputs found
Simulación de medios participativos
Probablemente uno de los propósitos mas difíciles de la Computación Gráfica es la simulación fotorealista de la naturaleza basándose en las leyes físicas. Este es el caso de la simulación de la interacción de la luz con los diferentes elementos naturales, la cual sigue un comportamiento realmente complejo, más aún si se considera la propagación de la misma a través de medios no homogeneos.
Los métodos tradicionales de plasmado de escenarios con ray tracing consideran que los rayos se trasladan en línea recta desde la fuente de luz hacia el ojo sin sufrir alteración alguna.
En la realidad, los rayos de luz varían su estructura y trayectoria dependiendo de las características del medio que éste atraviesa.
En los últimos años, se ha prestado especial atención al desarrollo de nuevos métodos que consideren las particularidades del medio en el cual se encuentra el escenario a plasmar, con el objeto de obtener representaciones sintéticas mas realistasEje: Computación gráfica, visualización e imágenesRed de Universidades con Carreras en Informática (RedUNCI
Simulación de medios participativos
Probablemente uno de los propósitos mas difíciles de la Computación Gráfica es la simulación fotorealista de la naturaleza basándose en las leyes físicas. Este es el caso de la simulación de la interacción de la luz con los diferentes elementos naturales, la cual sigue un comportamiento realmente complejo, más aún si se considera la propagación de la misma a través de medios no homogeneos.
Los métodos tradicionales de plasmado de escenarios con ray tracing consideran que los rayos se trasladan en línea recta desde la fuente de luz hacia el ojo sin sufrir alteración alguna.
En la realidad, los rayos de luz varían su estructura y trayectoria dependiendo de las características del medio que éste atraviesa.
En los últimos años, se ha prestado especial atención al desarrollo de nuevos métodos que consideren las particularidades del medio en el cual se encuentra el escenario a plasmar, con el objeto de obtener representaciones sintéticas mas realistasEje: Computación gráfica, visualización e imágenesRed de Universidades con Carreras en Informática (RedUNCI
The Carnegie Supernova Project. I. Third Photometry Data Release of Low-redshift Type Ia Supernovae and Other White Dwarf Explosions
We present final natural-system optical (ugriBV) and near-infrared (YJH) photometry of 134 supernovae (SNe) with probable white dwarf progenitors that were observed in 2004-2009 as part of the first stage of the Carnegie Supernova Project (CSP-I). The sample consists of 123 Type Ia SNe, 5 Type Iax SNe, 2 super-Chandrasekhar SN candidates, 2 Type Ia SNe interacting with circumstellar matter, and 2 SN 2006bt-like events. The redshifts of the objects range from to 0.0835; the median redshift is 0.0241. For 120 (90%) of these SNe, near-infrared photometry was obtained. Average optical extinction coefficients and color terms are derived and demonstrated to be stable during the five CSP-I observing campaigns. Measurements of the CSP-I near-infrared bandpasses are also described, and near-infrared color terms are estimated through synthetic photometry of stellar atmosphere models. Optical and near-infrared magnitudes of local sequences of tertiary standard stars for each supernova are given, and a new calibration of Y-band magnitudes of the Persson et al. standards in the CSP-I natural system is presented.Fil: Krisciunas, Kevin. Texas A&M University; Estados UnidosFil: Contreras, Carlos. University Aarhus; Dinamarca. Las Campanas Observatory; ChileFil: Burns, Christopher R.. Las Campanas Observatory; ChileFil: Phillips, M. M.. Las Campanas Observatory; ChileFil: Stritzinger, Maximilian D.. Las Campanas Observatory; Chile. University Aarhus; DinamarcaFil: Morrell, Nidia Irene. Las Campanas Observatory; ChileFil: Hamuy, Mario. Universidad de Chile; ChileFil: Anais, Jorge. Las Campanas Observatory; ChileFil: Boldt, Luis. Las Campanas Observatory; ChileFil: Busta, Luis. Las Campanas Observatory; ChileFil: Campillay, Abdo. Las Campanas Observatory; ChileFil: Castellón, Sergio. Las Campanas Observatory; ChileFil: Folatelli, Gaston. Las Campanas Observatory; Chile. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas; ArgentinaFil: Freedman, Wendy L.. University of Chicago; Estados UnidosFil: González, Consuelo. Las Campanas Observatory; ChileFil: Hsiao, Eric Y.. Florida State University; Estados Unidos. University Aarhus; Dinamarca. Las Campanas Observatory; ChileFil: Krzeminski, Wojtek. Las Campanas Observatory; ChileFil: Persson, Sven Eric. Carnegie Observatories;Fil: Roth, Miguel. Gmto Corporation; Chile. Las Campanas Observatory; ChileFil: Salgado, Francisco. Leiden Observatory Research Institute; . Las Campanas Observatory; ChileFil: Serón, Jacqueline. Las Campanas Observatory; Chile. Cerro Tololo Inter American Observatory; ChileFil: Suntzeff, Nicholas B.. Texas A&M University; Estados UnidosFil: Torres, Simón. Soar Telescope; Chile. Las Campanas Observatory; ChileFil: Filippenko, Alexei V.. University of California at Berkeley; Estados UnidosFil: Li, Weidong. University of California at Berkeley; Estados UnidosFil: Madore, Barry F.. Jet Propulsion Laboratory, California Institute Of Technology; . Las Campanas Observatory; ChileFil: DePoy, D.L.. Texas A&M University; Estados UnidosFil: Marshall, Jennifer L.. Texas A&M University; Estados UnidosFil: Rheault, Jean Philippe. Texas A&M University; Estados UnidosFil: Villanueva, Steven. Texas A&M University; Estados Unidos. Ohio State University; Estados Unido
Carnegie Supernova Project-II: Extending the Near-Infrared Hubble Diagram for Type Ia Supernovae to
The Carnegie Supernova Project-II (CSP-II) was an NSF-funded, four-year
program to obtain optical and near-infrared observations of a "Cosmology"
sample of Type Ia supernovae located in the smooth Hubble flow (). Light curves were also obtained of a "Physics"
sample composed of 90 nearby Type Ia supernovae at selected for
near-infrared spectroscopic time-series observations. The primary emphasis of
the CSP-II is to use the combination of optical and near-infrared photometry to
achieve a distance precision of better than 5%. In this paper, details of the
supernova sample, the observational strategy, and the characteristics of the
photometric data are provided. In a companion paper, the near-infrared
spectroscopy component of the project is presented.Comment: 43 pages, 10 figures, accepted for publication in PAS
SN 2012fr: Ultraviolet, Optical, and Near-infrared Light Curves of a Type Ia Supernova Observed within a Day of Explosion
We present detailed ultraviolet, optical, and near-infrared light curves of the Type Ia supernova (SN) 2012fr, which exploded in the Fornax cluster member NGC 1365. These precise high-cadence light curves provide a dense coverage of the flux evolution from −12 to +140 days with respect to the epoch of B-band maximum (tBmax). Supplementary imaging at the earliest epochs reveals an initial slow and nearly linear rise in luminosity with a duration of ∼2.5 days, followed by a faster rising phase that is well reproduced by an explosion model with a moderate amount of 56Ni mixing in the ejecta. From our analysis of the light curves, we conclude that: (i) the explosion occurred 1800 Å) luminosity was 16.5 ± 0.6 days, (iii) the supernova suffered little or no host-galaxy dust reddening, (iv) the peak luminosity in both the optical and near-infrared was consistent with the bright end of normal Type Ia diversity, and (v) 0.60 ± 0.15 M⊙ of 56Ni was synthesized in the explosion. Despite its normal luminosity, SN 2012fr displayed unusually prevalent high-velocity Ca II and Si II absorption features, and a nearly constant photospheric velocity of the Si II λ6355 line at ∼12,000 km s-1 that began ∼5 days before tBmax. We also highlight some of the other peculiarities in the early phase photometry and the spectral evolution. SN 2012fr also adds to a growing number of Type Ia supernovae that are hosted by galaxies with direct Cepheid distance measurements.Facultad de Ciencias Astronómicas y GeofísicasInstituto de Astrofísica de La Plat
Carnegie Supernova Project-I and -II: Measurements of using Cepheid, TRGB, and SBF Distance Calibration to Type Ia Supernovae
We present an analysis of Type Ia Supernovae (SNe~Ia) from both the Carnegie
Supernova Project~I (CSP-I) and II (CSP-II), and extend the Hubble diagram from
the optical to the near-infrared wavelengths (). We calculate the
Hubble constant, , using various distance calibrators: Cepheids, Tip of
the Red Giant Branch (TRGB), and Surface Brightness Fluctuations (SBF).
Combining all methods of calibrations, we derive $\rm H_0=71.76 \pm 0.58 \
(stat) \pm 1.19 \ (sys) \ km \ s^{-1} \ Mpc^{-1}B\rm
H_0=73.22 \pm 0.68 \ (stat) \pm 1.28 \ (sys) \ km \ s^{-1} \ Mpc^{-1}H1.2\sim 1.3 \rm \ km \
s^{-1} \ Mpc^{-1}H_0H_0H_0Y0.12\pm0.01\sigma_{int}$). We revisit SN~Ia Hubble residual-host mass correlations and
recover previous results that these correlations do not change significantly
between the optical and the near-infrared wavelengths. Finally, SNe~Ia that
explode beyond 10 kpc from their host centers exhibit smaller dispersion in
their luminosity, confirming our earlier findings. Reduced effect of dust in
the outskirt of hosts may be responsible for this effect.Comment: Revised calculations are made. Will be resubmitted to Ap
Dietary patterns and blood pressure in Southern Cone of Latin America
Background and aims: in the Southern Cone of Latin America, previous studies have shown that blood hypertension is one of the most significant risk factor for cardiovascular disease, and diet plays a fundamental role. We analyzed the cross-sectional relationship between dietary patterns (DP) and blood pressure values in people involved in the CESCAS I Study. Methods and results: the participants (n = 4626) were derived from randomly selected samples in 4 cities (Bariloche and Marcos Paz, Argentina; Temuco, Chile; and Pando-Barros Blancos, Uruguay). To define DP, a food-frequency questionnaire was applied and principal component analysis was performed. Blood pressure was determined according to standardized guidelines. A multivariate regression model was developed to determine the association between each DP and blood pressure values, according to the quartile (Q) of adherence to DP. Two predominant DP were detected, Prudent (PDP, higher consumption of fruits, vegetables, legumes, whole grains, fish, seafood and nuts) and Western (WDP, higher consumption of red and processed meats, dressings, sweets, snacks and refined grains). A significant inverse association was found between adherence to PDP and systolic and diastolic blood pressure (−1.85 and −1.29 mmHg for Q4 vs Q1, respectively). Adherence to WDP was positively associated with systolic blood pressure (2.09 mmHg for Q4 vs Q1). Conclusion: the WDP detected in the studied population is positively associated with higher levels of blood pressure, while greater adherence to healthy DP has a positive impact on blood pressure.Fil: Defagó, María Daniela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Ciencias de la Salud. Universidad Nacional de Córdoba. Instituto de Investigaciones en Ciencias de la Salud; Argentina. Universidad Nacional de Córdoba. Facultad de Medicina. Escuela de Nutrición; Argentina. Instituto de Efectividad Clínica y Sanitaria; Argentina. Harvard University. Harvard School of Public Health; Estados UnidosFil: Mozaffarian, Dariush. Tufts University; Estados UnidosFil: Irazola, Vilma. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto de Efectividad Clínica y Sanitaria; ArgentinaFil: Gutierrez, Laura. Instituto de Efectividad Clínica y Sanitaria; ArgentinaFil: Poggio, Rosana. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto de Efectividad Clínica y Sanitaria; ArgentinaFil: Serón, Pamela. Universidad de La Frontera; ChileFil: Mores, Nora Cecilia. Municipalidad de Marcos Paz (buenos Aires).; ArgentinaFil: Calandrelli, Matías Enrique. Instituto de Efectividad Clínica y Sanitaria; ArgentinaFil: Ponzo, Jacqueline. Universidad de la República; UruguayFil: Rubinstein, Adolfo Luis. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto de Efectividad Clínica y Sanitaria; ArgentinaFil: Elorriaga, Natalia. Instituto de Efectividad Clínica y Sanitaria; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Centro de Investigaciones en Epidemiología y Salud Pública. Instituto de Efectividad Clínica y Sanitaria. Centro de Investigaciones en Epidemiología y Salud Pública; Argentin
Estimating prevalence of chronic obstructive pulmonary disease in the Southern Cone of Latin America: how different spirometric criteria may affect disease burden and health policies
Abstract Background Chronic obstructive pulmonary disease (COPD) is the fourth leading cause of death worldwide. The study aimed to determine and compare the prevalence of COPD in the general population aged 45-74 years old according to fixed ratio and lower limit of normal (LLN) thresholds in four cities in the Southern Cone of Latin America. Methods The Pulmonary Risk in South America (PRISA) study used a 4-stage stratified sampling method to select 5814 participants from 4 cities in the Southern Cone of Latin America (Bariloche and Marcos Paz, Argentina; Temuco, Chile; and Pando-Barros Blancos, Uruguay). Data on demographic information, medical history, risk factors, pre-bronchodilator and post-bronchodilator spirometry were obtained using a standard protocol. According to GOLD, COPD was defined as a post-bronchodilator ratio of forced expiratory volume in one second (FEV1) over forced vital capacity (FVC) less than 70%. The LLN threshold was defined as the lower fifth percentile for predicted FEV1/FVC, and was evaluated as an alternative COPD definition. Results Overall COPD prevalence was 9.3% (95% CI 8.4, 10.2%), and men had a higher prevalence [11.8% (95% CI 10.3, 13.3%)] than women [7.3% (95% CI 6.2, 8.3%)] with the fixed ratio. Overall COPD prevalence using LLN was 4.7% (95% CI 4.1, 5.3%), higher in men: 5.8% (95% CI 4.7, 6.8%) than women: 3.9% (95% CI 3.1, 4.7%). COPD prevalence was significantly higher among those who were older, had <high-school education and lower body-mass index, were cigarette smokers, and had self-reported history of asthma and tuberculosis. Conclusions First, COPD and its risk factors are highly prevalent in the general population of Argentina, Chile, and Uruguay. Second, the prevalence of COPD by LLN criterion was significantly lower with lesser degrees of severity compared to fixed ratio of FEV1/FVC. Implementing LLN criterion instead of fixed ratio of FEV1/FVC may reduce the risk of over-diagnosis of COPD, although further prognostic studies of COPD adverse outcomes should be conducted using both definitions. Third, these data suggest that national efforts on the prevention, treatment, and control of COPD should be a public health priority in the Southern Cone of Latin America
Carnegie Supernova Project-II: Extending the Near-infrared Hubble Diagram for Type Ia Supernovae to z ∼ 0.1
The Carnegie Supernova Project-II (CSP-II) was an NSF-funded, four-year program to obtain optical and near-infrared observations of a "Cosmology" sample of ∼100 Type Ia supernovae located in the smooth Hubble flow (0.03 ≲ z ≲ 0.10). Light curves were also obtained of a "Physics" sample composed of 90 nearby Type Ia supernovae at z ≤ 0.04 selected for near-infrared spectroscopic timeseries observations. The primary emphasis of the CSP-II is to use the combination of optical and near-infrared photometry to achieve a distance precision of better than 5%. In this paper, details of the supernova sample, the observational strategy, and the characteristics of the photometric data are provided. In a companion paper, the near-infrared spectroscopy component of the project is presented.Fil: Phillips, Mark. Las Campanas Observatory; ChileFil: Contreras Velásquez, Carlos. Las Campanas Observatory; ChileFil: Hsiao, Eric. Las Campanas Observatory; Chile. University Aarhus; Dinamarca. Florida State University; Estados UnidosFil: Morrell, Nidia Irene. Las Campanas Observatory; Chile. 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: Burns, Christopher R.. Observatories of the Carnegie Institution for Science; Estados UnidosFil: Stritzinger, Maximilian. University Aarhus; DinamarcaFil: Ashall, Chris. Florida State University; Estados UnidosFil: Freedman, Wendy L.. Observatories of the Carnegie Institution for Science; Estados Unidos. University of Chicago; Estados UnidosFil: Hoeflich, Peter. Florida State University; Estados UnidosFil: Persson, S. E.. Observatories of the Carnegie Institution for Science; Estados UnidosFil: Piro, Anthony. Observatories of the Carnegie Institution for Science; Estados UnidosFil: Suntzeff, Nicholas B.. Texas A&M University; Estados UnidosFil: Uddin, Syed A.. Observatories of the Carnegie Institution for Science; Estados UnidosFil: Anais, Jorge. Las Campanas Observatory; ChileFil: Baron, Edward. Oklahoma State University; Estados UnidosFil: Busta, Luis. Las Campanas Observatory; ChileFil: Campillay, Abdo. Las Campanas Observatory; Chile. Universidad de La Serena; ChileFil: Castellón, Sergio. Las Campanas Observatory; ChileFil: Corco, Carlos. Las Campanas Observatory; Chile. Soar Telescope; ChileFil: Diamond, Tiara. Florida State University; Estados Unidos. Laboratory of Observational Cosmology; Estados UnidosFil: Gall, Christa. University Aarhus; Dinamarca. Universidad de Copenhagen; DinamarcaFil: Gonzalez, Consuelo. Las Campanas Observatory; ChileFil: Holmbo, Simon. University Aarhus; DinamarcaFil: Krisciunas, Kevin. Texas A&M University; Estados UnidosFil: Roth, Miguel. Las Campanas Observatory; Chile. GMTO Corporation; ChileFil: Serón, Jacqueline. Las Campanas Observatory; Chile. Cerro Tololo Inter American Observatory; ChileFil: Taddia, F.. Stockholms Universitet; SueciaFil: Torres, Simón. Soar Telescope; ChileFil: Anderson, Joseph. European Southern Observatory Chile; ChileFil: Folatelli, Gaston. 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; Argentin
Erratum: The Carnegie Supernova Project I. Third Photometry Data Release of Low-redshift Type Ia Supernovae and Other White Dwarf Explosions (2017, AJ, 154, 211)
Errata del artículo mencionado.Este trabajo es una errata del artículo “The Carnegie Supernova Project. I. Third Photometry Data Release of Lowredshift Type Ia Supernovae and Other White Dwarf Explosions” (ver "Documentos relacionados").Instituto de Astrofísica de La Plat