1,724,154 research outputs found
Diagnóstico de la galaxia remanente de una fusión NGC 4382
No full textLos modelos existentes sobre formación de galaxias masivas, particularmente para las galaxias de tipo temprano, se centran en el concepto de formación de dos fases, in situ y ex situ. Ambas fases dejarían huellas en ellas, y estas podrían ser identificadas por separado. En este trabajo preliminar, nos enfocamos en el análisis de la galaxia elíptica dinámicamente joven NGC 4382 utilizando fotometría y espectroscopia profunda Gemini/GMOS. Nuestro estudio muestra que el sistema de cúmulos globulares de esta galaxia presenta más de dos subpoblaciones de cúmulos. Además de las típicas subpoblaciones de cúmulos con edades mayores a los 5 x 109 años, se determinó la presencia de cúmulos jóvenes que podrían ser producto de una fusión que tuvo NGC 4382 hace unos 2.8 x 109 años.Existing models on the formation of massive galaxies, particularly for early-type galaxies, focus on the concept of two-phase formation, in-situ and ex-situ. Both phases would leave footprints in the galaxies which could be identified separately. In this preliminary work, we focus on the analysis of the dynamically young elliptical galaxy NGC 4382 using deep Gemini/GMOS photometry and spectroscopy. Our study shows that the globular cluster system of this galaxy has more than two subpopulations of clusters. In addition to the typical cluster subpopulations older than 5 Gyr, the presence of young clusters was determined that could be the product of a merger that NGC 4382 had about 2.8 Gyr ago.Asociación Argentina de Astronomí
Linked collectors and determiners for: Museu Paraense Emílio Goeldi - Chelonia Collection.
No full textNatural history specimen data linked to collectors and determiners held within, "Museu Paraense Emílio Goeldi - Chelonia Collection". Claims or attributions were made on Bionomia by volunteer Scribes, <a href="http://bionomia.net/dataset/fb7082a0-5e66-4382-94df-4c5c4e57cda3">https://bionomia.net/dataset/fb7082a0-5e66-4382-94df-4c5c4e57cda3</a> using specimen data from the dataset aggregated by the Global Biodiversity Information Facility, <a href="https://gbif.org/dataset/fb7082a0-5e66-4382-94df-4c5c4e57cda3">https://gbif.org/dataset/fb7082a0-5e66-4382-94df-4c5c4e57cda3</a>. Formatted as a Frictionless Data package
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
No full text“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Induction of heme oxygenase I (HMOX1) by HPP-4382: a novel modulator of Bach1 activity.
No full textOxidative stress is generated by reactive oxygen species (ROS) produced in response to metabolic activity and environmental factors. Increased oxidative stress is associated with the pathophysiology of a broad spectrum of inflammatory diseases. Cellular response to excess ROS involves the induction of antioxidant response element (ARE) genes under control of the transcriptional activator Nrf2 and the transcriptional repressor Bach1. The development of synthetic small molecules that activate the protective anti-oxidant response network is of major therapeutic interest. Traditional small molecules targeting ARE-regulated gene activation (e.g., bardoxolone, dimethyl fumarate) function by alkylating numerous proteins including Keap1, the controlling protein of Nrf2. An alternative is to target the repressor Bach1. Bach1 has an endogenous ligand, heme, that inhibits Bach1 binding to ARE, thus allowing Nrf2-mediated gene expression including that of heme-oxygenase-1 (HMOX1), a well described target of Bach1 repression. In this report, normal human lung fibroblasts were used to screen a collection of synthetic small molecules for their ability to induce HMOX1. A class of HMOX1-inducing compounds, represented by HPP-4382, was discovered. These compounds are not reactive electrophiles, are not suppressed by N-acetyl cysteine, and do not perturb either ROS or cellular glutathione. Using RNAi, we further demonstrate that HPP-4382 induces HMOX1 in an Nrf2-dependent manner. Chromatin immunoprecipitation verified that HPP-4382 treatment of NHLF cells reciprocally coordinated a decrease in binding of Bach1 and an increase of Nrf2 binding to the HMOX1 E2 enhancer. Finally we show that HPP-4382 can inhibit Bach1 activity in a reporter assay that measures transcription driven by the human HMOX1 E2 enhancer. Our results suggest that HPP-4382 is a novel activator of the antioxidant response through the modulation of Bach1 binding to the ARE binding site of target genes
Appropriate Similarity Measures for Author Cocitation Analysis
No full textWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Diagnóstico de la galaxia remanente de una fusion NGC 4382
No full textLos modelos existentes sobre formación de galaxias masivas, particularmente para las galaxiasde tipo temprano, se centran en el concepto de formación de dos fases, in situ y ex situ. Ambas fases dejarían huellas en ellas, y estas podrían ser identificadas por separado. En este trabajo preliminar, nos enfocamos en el análisis de la galaxia elíptica dinámicamente joven NGC 4382 utilizando fotometría y espectroscopía profunda Gemini/GMOS. Nuestro estudio muestra que el sistema de cúmulos globulares de esta galaxia presenta más de dos subpoblaciones de cúmulos. Además de las típicas subpoblaciones de cúmulos con edades mayores a los 5 × 10^9 años, se determinó la presencia de cúumulos jóvenes que podrían ser producto de una fusión que tuvo NGC 4382 hace unos 2.8 × 109años.Existing models on the formation of massive galaxies, particularly for early-type galaxies, focus on the concept of two-phase formation, in-situ and ex-situ. Both phases would leave footprints in the galaxies which could be identified separately. In this preliminary work, we focus on the analysis of the dynamically young elliptical galaxy NGC 4382 using deep Gemini/GMOS photometry and spectroscopy. Our study shows that the globular cluster system of this galaxy has more than two subpopulations of clusters. In addition to the typical cluster subpopulations older than 5 Gyr, the presence of young clusters was determined that could be the product of a merger that NGC 4382 had about 2.8 Gyr ago.Fil: Escudero, Carlos Gabriel. 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: Sesto, Leandro Alberto. 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: Faifer, Favio Raúl. 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: Smith Castelli, Analia 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; ArgentinaFil: Reynaldi, María Victoria. 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; Argentina62° Reunión Anual de la Asociación Argentina de AstronomíaArgentinaAsociación Argentina de Astronomí
Clues on the stellar content of disturbed early-type galaxies: the case of NGC 4382
No full textNGC 4382 es una galaxia masiva de tipo temprano del cúmulo de Virgo. Este objeto presenta claras evidencias de haber sufrido eventos de interacción y fusión en los últimos miles de millones de años, pero también hemos confirmado recientemente la presencia de cúmulos globulares jóvenes. En tal contexto, representa un caso atractivo para estudiar diversos aspectos de la historia de ensamble de las galaxias de tipo temprano, en particular la influencia del medio sobre sus propiedades globales. En este trabajo nos focalizamos en analizar la historia de formación estelar en distintos radios galactocéntricos. Para ello empleamos la técnica del ajuste espectral completo sobre espectros de ranura larga obtenidos con el Telescopio Gemini Norte y la cámara GMOS.
Nuestros resultados preliminares muestran que, como es usual en este tipo de objetos, NGC 4382 ha formado estrellas de manera significativa hace unos 1010 años. Sin embargo, luego de atravesar una etapa de pasividad, esta galaxia ha vuelto a formar poblaciones estelares, posiblemente en más de un brote, y a partir de material previamente enriquecido.NGC 4382 is a massive early-type galaxy, belonging to Virgo cluster. This galaxy shows clear evidence of having gone through interactions and mergers in the last few Gyr. Recently, we have studied its globular cluster content and confirmed the presence of a young globular cluster population in addition to the elder one. Does this galaxy hide more clues about such a switch-on of stellar formation? We are looking for traces of the star formation history applying a full-spectrum fitting technique to Gemini/GMOS longslit data at different galactocentric radii.
Our preliminary results shows that, as expected in early type systems, NGC 4382 has formed the bulk of its stellar content 1010 years ago. However, it indeed reignited star formation (and likely more than once since the main burst) with enriched interstellar matter.Asociación Argentina de AstronomíaInstituto de Astrofísica de La Plat
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