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Search Results: 1 - 10 of 411697 matches for " Alejandra M. Mu?oz Arancibia "
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Properties of Submillimeter Galaxies in a Semi-analytic Model using the "Count Matching" Approach: Application to the ECDF-S
Alejandra M. Muoz Arancibia,Felipe P. Navarrete,Nelson D. Padilla,Sofía A. Cora,Eric Gawiser,Peter L. Kurczynski,Andrés N. Ruiz
Physics , 2014, DOI: 10.1093/mnras/stu2237
Abstract: We present a new technique for modeling submillimeter galaxies (SMGs): the "Count Matching" approach. Using lightcones drawn from a semi-analytic model of galaxy formation, we choose physical galaxy properties given by the model as proxies for their submillimeter luminosities, assuming a monotonic relationship. As recent interferometric observations of the Extended Chandra Deep Field South show that the brightest sources detected by single-dish telescopes are comprised by emission from multiple fainter sources, we assign the submillimeter fluxes so that the combined LABOCA plus bright-end ALMA observed number counts for this field are reproduced. After turning the model catalogs given by the proxies into submillimeter maps, we perform a source extraction to include the effects of the observational process on the recovered counts and galaxy properties. We find that for all proxies, there are lines of sight giving counts consistent with those derived from LABOCA observations, even for input sources with randomized positions in the simulated map. Comparing the recovered redshift, stellar mass and host halo mass distributions for model SMGs with observational data, we find that the best among the proposed proxies is that in which the submillimeter luminosity increases monotonically with the product between dust mass and SFR. This proxy naturally reproduces a positive trend between SFR and bolometric IR luminosity. The majority of components of blended sources are spatially unassociated.
Calibration of semi-analytic models of galaxy formation using Particle Swarm Optimization
Andrés N. Ruiz,Sofía A. Cora,Nelson D. Padilla,Mariano J. Domínguez,Cristian A. Vega-Martínez,Tomás E. Tecce,álvaro Orsi,Yamila C. Yaryura,Diego García Lambas,Ignacio D. Gargiulo,Alejandra M. Muoz Arancibia
Physics , 2013, DOI: 10.1088/0004-637X/801/2/139
Abstract: We present a fast and accurate method to select an optimal set of parameters in semi-analytic models of galaxy formation and evolution (SAMs). Our approach compares the results of a model against a set of observables applying a stochastic technique called Particle Swarm Optimization (PSO), a self-learning algorithm for localizing regions of maximum likelihood in multidimensional spaces that outperforms traditional sampling methods in terms of computational cost. We apply the PSO technique to the SAG semi-analytic model combined with merger trees extracted from a standard $\Lambda$CDM N-body simulation. The calibration is performed using a combination of observed galaxy properties as constraints, including the local stellar mass function and the black hole to bulge mass relation. We test the ability of the PSO algorithm to find the best set of free parameters of the model by comparing the results with those obtained using a MCMC exploration. Both methods find the same maximum likelihood region, however the PSO method requires one order of magnitude less evaluations. This new approach allows a fast estimation of the best-fitting parameter set in multidimensional spaces, providing a practical tool to test the consequences of including other astrophysical processes in SAMs.
Estrategias de afrontamiento en adolescentes
Veloso-Besio, Constanza;Caqueo-Arancibia, Washington;Caqueo-Urízar, Alejandra;Muoz-Sánchez, Zunilda;Villegas-Abarzúa, Francisca;
Fractal : Revista de Psicologia , 2010, DOI: 10.1590/S1984-02922010000100003
Abstract: this study aimed to describe and analyze the coping strategies that adolescents have in school. the total sample consisted of 323 adolescents, students (184 men and 139 women) from eighth to fourth year basic middle belonging to different educational institutions in the city of arica (chile): private (90), private subsidized (114) and municipal (119). all of them received the asc scale frydenberg and lewis (1997). there were significant differences between the types of educational establishments, with the individual establishment funded which showed greater variety of coping strategies used. implications are discussed in light of the results found.
Orofacial Characteristics in Relation to the Need of Orthodontic Treatments in Children
Sandoval Vidal,Paulo; Ceballos Casanova,Mónica; Acevedo Atala,Claudia; Jans Muoz,Alejandra;
International journal of odontostomatology , 2010, DOI: 10.4067/S0718-381X2010000100010
Abstract: malocclusion represents a public health problem in chile. government policies create preventive and interceptive programs for these conditions. nevertheless, there are no uniform criteria for the selection of patients who need early treatment; the decision is made by a specialist during orthodontic treatment. here, we propose the index for early intervention (iei) for early detection of malocclusions. we treat malocclusions with a simple interceptive treatment to minimize or eliminate the need for orthodontic treatment in a child population. furthermore, the iei can be used in general dentistry as a screening method. the purpose of this study was to compare the reliability and validity of an index used to assess the need for orthodontic treatment, as compared to the view of a panel of experts formed by three orthodontists. we used a set of 55 study casts representing all types of malocclusion. the accuracy of the diagnostic or the validity of each index was calculated using the opinions of three orthodontic raters as a “gold standard;” these measures obtained an agreement of 0.82. receiver operating characteristic curves was plotted for the index. results: diagnostic accuracy was determined by the area under the curve, the cut point was 20, sensitivity was 0.977 and specificity was 0.167. conclusions: this occlusal index provided valuable information for selecting children in need of early and simple orthodontic treatment.
Alejandra Martínez RM,David Hardisson H,Mar Muoz M,Francisco Gómez P
Revista Chilena de Obstetricia y Ginecología , 2008,
Abstract: Antecedentes: El tumor phyllodes (TP) es un tumor poco común y aunque el 34,5-63,7% son benignos, el resto tienen un comportamiento borderline o maligno. Caso clínico: Paciente de 47 a os derivada a nuestro centro para valoración por TP recidivante operado previamente tres veces con el resultado de TP de bajo grado con márgenes afectados. Al llegar a nuestro centro presenta un nodulo subcicatricial que se trata mediante escisión con el diagnóstico anatomopatológico de osteosarcoma osteoblástico de alto grado NI/ IV. Al estar con los márgenes afectados se trata posteriormente con cuadrantectomía más quimioterapia. Al terminar el tratamiento se objetivan en el TC torácico múltiples nodulos pulmonares compatibles con metástasis y se decide iniciar quimioterapia con otro esquema pero la paciente no responde y fallece por complicaciones derivadas de la progresión de su enfermedad pulmonar. Discusión: La cirugía es la base del tratamiento del TP, siendo la escisión local con márgenes suficientes, superiores a 1 -2 cm, el tratamiento de elección. La enucleación tumoral se considera insuficiente. La afectación tumoral de la axila ocurre en menos de 5-10% de las pacientes por lo que la exploración quirúrgica de la axila no se recomienda de rutina. Conclusión: La transformación osteosarcomatosa es una situación poco común, pero una cirugía incompleta en un TP maligno permite la desdiferenciación del componente estromal en sarcoma, incluso si el tumor inicial es de bajo grado. El pronóstico se ensombrece mucho, sobre todo si la transformación sarcomatosa contiene componentes heterólogos, como en este caso. Background: Phyllodes tumor (TP) is a rare tumor. The majority of them have been described as benign, with the reminder divided between borderline and malignant tumors. Case description: 47-year-old patient derived to our hospital to evalúate a recurrent TP after three local failures. Surgical removal of tumor had positive margins in the previous surgeries. She presented to our service with a nodule in the scar that was resected. The pathology diagnosis revealed a poor differentiated osteosarcoma. As surgical margins were cióse, the treatment was completed with a wide local reexcision and adequate surgical margins plus chemotherapy. Múltiple pulmonary nodules compatible with metástasis were targeted in the thoracic TC during follow-up and another chemotherapy scheme was initiated. The patient did not respond and died due to the progression of her pulmonary disease. Discussion: Surgical removal is the mainstay of TP treatment and wide excisión with adequate margi
Efecto de los cambios del medio ambiente en la salud humana, animal y de las plantas.
Dra. en C. María Alejandra Moreno García,Lic Yersinia Alejandra Muoz Moreno,Est. Claudia Yadira Muoz Moreno,M. en C. José Jesús Muoz Escobedo
REDVET , 2012,
Abstract: Resumen.En el último decenio se han presentado cambios importantes en el medio ambiente.
Chemo-Archaeological Downsizing in a Hierarchical Universe: Impact of a Top Heavy IGIMF
I. D. Gargiulo,S. A. Cora,N. D. Padilla,A. M. Muoz Arancibia,A. N. Ruiz,A. A. Orsi,T. E. Tecce,C. Weidner,G. Bruzual
Physics , 2014, DOI: 10.1093/mnras/stu2272
Abstract: We make use of a semi-analytical model of galaxy formation to investigate the origin of the observed correlation between [a/Fe] abundance ratios and stellar mass in elliptical galaxies. We implement a new galaxy-wide stellar initial mass function (Top Heavy Integrated Galaxy Initial Mass Function, TH-IGIMF) in the semi-analytic model SAG and evaluate its impact on the chemical evolution of galaxies. The SFR-dependence of the slope of the TH-IGIMF is found to be key to reproducing the correct [a/Fe]-stellar mass relation. Massive galaxies reach higher [a/Fe] abundance ratios because they are characterized by more top-heavy IMFs as a result of their higher SFR. As a consequence of our analysis, the value of the minimum embedded star cluster mass and of the slope of the embedded cluster mass function, which are free parameters involved in the TH-IGIMF theory, are found to be as low as 5 solar masses and 2, respectively. A mild downsizing trend is present for galaxies generated assuming either a universal IMF or a variable TH-IGIMF. We find that, regardless of galaxy mass, older galaxies (with formation redshifts > 2) are formed in shorter time-scales (< 2 Gyr), thus achieving larger [a/Fe] values. Hence, the time-scale of galaxy formation alone cannot explain the slope of the [a/Fe]-galaxy mass relation, but is responsible for the big dispersion of [a/Fe] abundance ratios at fixed stellar mass.We further test the hyphothesis of a TH-IGIMF in elliptical galaxies by looking into mass-to-light ratios, and luminosity functions. Models with a TH-IGIMF are also favoured by these constraints. In particular, mass-to-light ratios agree with observed values for massive galaxies while being overpredicted for less massive ones; this overprediction is present regardless of the IMF considered.
Macedonio Fernández: su tesis inédita De las personas
Marisa Alejandra Muoz
Cuyo Anuario de Filosofía Argentina y Americana , 2010,
Reconstrucción torácica primaria con material protésico en trauma torácico extenso
Revista chilena de cirugía , 2007, DOI: 10.4067/S0718-40262007000600012
Abstract: we report a 21 years old woman that was admitted in the emergency room due to a extensive chest trauma caused by a gunshot. the patient was subjected to an emergency thoracotomy. a right lung lower and middle lobectomy, partial hepatectomy, diaphragmatic suture and mastectomy were performed. a primary chest closure was done, using a marlex prosthesis covered by a cutaneous flap. during the postoperative period, the patient had a surgical wound infection, that was treated conservatively and was discharged 42 days after surgery
Eritrodermia exfoliativa y dermatitis infecciosa en un lactante infectado por el virus linfotrópico humano-I (HTLV-I)
Pérez C,Lilian; Villarroel B,Julia; Reyes J,Alejandra; Benavides M,Alicia; Muoz O,Carla;
Revista chilena de infectología , 2007, DOI: 10.4067/S0716-10182007000200009
Abstract: we report a htlv-i positive infant, whose infection was confirmed by polymerase chain reaction. the infant presented with an acute, severe, generalized eczema, exfoliation and severe erythroderma that yielded to an acute proteic malnutrition and frequent staphyloccocal infections, unresponsive to treatment, since the second month of life. immunodeficiencies from other origin and other causes of erythroderma were ruled out. the histopathology studies and clinical course yielded to the diagnosis of infective dermatitis associated to htlv-i. a review of the literature is performed
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