979 research outputs found
Te saco el Pombo y te pongo el Sacco : Hacia una superación de falsas dicotomías en los discursos sobre el arte
En el presente trabajo se ensayará un análisis introductorio acerca de la producción de artes en Argentina durante los 90s y, a su vez, respecto del funcionamiento y la relación particular de dos obras producidas durante la década, las cuales han sido expuestas en febrero de 2009 en el Museo de Arte Castagnino-Macro de la ciudad santafecina de Rosario. La muestra llevó el nombre Te saco el Pombo y te pongo el Sacco, su propuesta curatorial estuvo a cargo del crítico Roberto Echen y las obras presentadas fueron "Dos cepitas" de Marcelo Pombo (Fig 1) y "El incendio y las vísperas" de Graciela Sacco (Fig. 2). El abordaje de esta muestra y de su propuesta curatorial, así como de las obras expuestas, nos permitirá la revisión y puesta en cuestión de las categorías y clasificaciones que la crítica, la historia y la teoría del arte han venido utilizando para el análisis de las prácticas artísticas en las supuestas y diferenciadas coordenadas de "lo social", "lo político", "lo puramente estético" y "lo propiamente artístico". Las reflexiones y tesis de Jacques Rancière en torno a lo político y lo estético nos servirán de apoyo y marco referencial para estas consideracione
Flame: A Flexible Data Reduction Pipeline for Near-Infrared and Optical Spectroscopy
We present flame, a pipeline for reducing spectroscopic observations obtained
with multi-slit near-infrared and optical instruments. Because of its flexible
design, flame can be easily applied to data obtained with a wide variety of
spectrographs. The flexibility is due to a modular architecture, which allows
changes and customizations to the pipeline, and relegates the
instrument-specific parts to a single module. At the core of the data reduction
is the transformation from observed pixel coordinates (x, y) to rectified
coordinates (lambda, gamma). This transformation consists in the polynomial
functions lambda(x,y) and gamma(x,y) that are derived from arc or sky emission
lines and slit edge tracing, respectively. The use of 2D transformations allows
one to wavelength calibrate and rectify the data using just one interpolation
step. Furthermore, the gamma(x,y) transformation includes also the spatial
misalignment between frames, which can be measured from a reference star
observed simultaneously with the science targets. The misalignment can then be
fully corrected during the rectification, without having to further resample
the data. Sky subtraction can be performed via nodding and/or modeling of the
sky spectrum; the combination of the two methods typically yields the best
results. We illustrate the pipeline by showing examples of data reduction for a
near-infrared instrument (LUCI at the Large Binocular Telescope) and an optical
one (LRIS at the Keck telescope).Comment: 17 pages, 10 figures, published in MNRAS. The pipeline is available
at https://github.com/siriobelli/flam
Arte, producción cultural y acción política: Castoriadis y una consideración integral, democrática y anti-formalista de nuestras capacidades humanas
El presente artículo constituye una introducción al original pensamiento del filósofo griego Cornelius Castoriadis. La articulación en sus planteos de elementos de la filosofía clásica, la teoría política yun psicoanálisis de corte antropológico nos ofrece una concepción integral de lo humano que permite vislumbrar la vida en sociedad y el desarrollo cultural como los sitios para el desenvolvimiento de su autonomía. Con Castoriadis, las relaciones entre praxis política y creación cultural son estrechas e indisociables, consideración que nos aleja de miradas esquemáticas y jerarquizantes que restan valor a ciertas prácticas, como las del arte,y ponderan otras, como una política escindida de la vida cotidiana. Y desde aquí se nos permite asistir a la restitución de capacidades compartidas para el ejercicio pleno de nuestra autonomía endemocracia.This article is an introduction to the original thought of the Greek philosopher Cornelius Castoriadis. The articulation in their approaches to elements of classical philosophy, political theory and anthropological psychoanalysis court offers a comprehensive conception of the human that offers a glimpse of life in society and cultural development as the sites for the developmentof their autonomy. With Castoriadis, relations between political practice and cultural creation aren arrow and inseparable, considering that distancesus from schematic and looks hierarchizing detract from certain practices, such as art, and pondering other, as a political split of everyday life. And from here we are allowed to attend the shared capabilities restitution for the full exercise of our autonomy in democracy.
On the Unusual Depletions toward Sk 155, or What Are the Small Magellanic Cloud Dust Grains Made of?
The dust in the Small Magellanic Cloud (SMC), an ideal analog of primordial
galaxies at high redshifts, differs markedly from that in the Milky Way by
exhibiting a steeply rising far-ultraviolet extinction curve, an absence of the
2175 Angstrom extinction feature, and a local minimum at ~12 micron in its
infrared emission spectrum, suggesting the lack of ultrasmall carbonaceous
grains (i.e. polycyclic aromatic hydrocarbon molecules) which are ubiquitously
seen in the Milky Way. While current models for the SMC dust all rely heavily
on silicates, recent observations of the SMC sightline toward Sk 155 indicated
that Si and Mg are essentially undepleted and the depletions of Fe range from
mild to severe, suggesting that metallic grains and/or iron oxides, instead of
silicates, may dominate the SMC dust. However, in this Letter we apply the
Kramers-Kronig relation to demonstrate that neither metallic grains nor iron
oxides are capable of accounting for the observed extinction; silicates remain
as an important contributor to the extinction, consistent with current models
for the SMC dust.Comment: 12 pages, 3 figures; The Astrophysical Journal Letters, in pres
Uncovering the Active Galactic Nuclei in Low-Ionization Nuclear Emission-Line Regions with Spitzer
The impact of active galactic nuclei on low-ionization nuclear emission-line
regions (LINERs) remains a vigorous field of study. We present preliminary
results from a study of the mid-infrared atomic emission lines of LINERs with
the Spitzer Space Telescope. We assess the ubiquity and properties of AGN in
LINERs using this data. We discuss what powers the mid-infrared emission lines
and conclude that the answer depends unsurprisingly on the emission line
ionization state and, more interestingly, on the infrared luminosity.Comment: To appear in ASP Vol. 373, The Central Engine of Active Galactic
Nuclei, ed. Luis C. Ho and Jian-Min Wang; 4 pages, 2 figure
Bacillus coagulans MA-13: A promising thermophilic and cellulolytic strain for the production of lactic acid from lignocellulosic hydrolysate
Background: The transition from a petroleum-based economy towards more sustainable bioprocesses for the production of fuels and chemicals (circular economy) is necessary to alleviate the impact of anthropic activities on the global ecosystem. Lignocellulosic biomass-derived sugars are suitable alternative feedstocks that can be fermented or biochemically converted to value-added products. An example is lactic acid, which is an essential chemical for the production of polylactic acid, a biodegradable bioplastic. However, lactic acid is still mainly produced by Lactobacillus species via fermentation of starch-containing materials, the use of which competes with the supply of food and feed. Results: A thermophilic and cellulolytic lactic acid producer was isolated from bean processing waste and was identified as a new strain of Bacillus coagulans, named MA-13. This bacterium fermented lignocellulose-derived sugars to lactic acid at 55 °C and pH 5.5. Moreover, it was found to be a robust strain able to tolerate high concentrations of hydrolysate obtained from wheat straw pre-treated by acid-catalysed (pre-)hydrolysis and steam explosion, especially when cultivated in controlled bioreactor conditions. Indeed, unlike what was observed in microscale cultivations (complete growth inhibition at hydrolysate concentrations above 50%), B. coagulans MA-13 was able to grow and ferment in 95% hydrolysate-containing bioreactor fermentations. This bacterium was also found to secrete soluble thermophilic cellulases, which could be produced at low temperature (37 °C), still retaining an optimal operational activity at 50 °C. Conclusions: The above-mentioned features make B. coagulans MA-13 an appealing starting point for future development of a consolidated bioprocess for production of lactic acid from lignocellulosic biomass, after further strain development by genetic and evolutionary engineering. Its optimal temperature and pH of growth match with the operational conditions of fungal enzymes hitherto employed for the depolymerisation of lignocellulosic biomasses to fermentable sugars. Moreover, the robustness of B. coagulans MA-13 is a desirable trait, given the presence of microbial growth inhibitors in the pre-treated biomass hydrolysate
Antifungal and anti-biofilm activity of the first cryptic antimicrobial peptide from an archaeal protein against Candida spp. clinical isolates
Candida species cause cutaneous and systemic infections with a high mortality rate, especially
in immunocompromised patients. The emergence of resistance to the most common antifungal
drugs, also due to bioflm formation, requires the development of alternative antifungal agents.
The antimicrobial peptide VLL-28, isolated from an archaeal transcription factor, shows comparable
antifungal activity against 10 clinical isolates of Candida spp. Using a fuoresceinated derivative of this
peptide, we found that VLL-28 binds to the surface of planktonic cells. This observation suggested
that it could exert its antifungal activity by damaging the cell wall. In addition, analyses performed on
bioflms via confocal microscopy revealed that VLL-28 is diferentially active on all the strains tested,
with C. albicans and C. parapsilosis being the most sensitive ones. Notably, VLL-28 is the frst example
of an archaeal antimicrobial peptide that is active towards Candida spp. Thus, this points to archaeal
microorganisms as a possible reservoir of novel antifungal agent
Antioxidant capacity of Rigenase®, a specific aqueous extract of triticum vulgare
Reactive species of oxygen (ROS), responsible for oxidative stress, accumulate in various
tissues damaged by burns, decubitus ulcers, and vascular lesions. Antioxidants play an important
and well-documented role in healing of chronic and acute wounds. Rigenase®, a specific extract of
Triticum vulgare manufactured by Farmaceutici Damor, is employed in products used for the
regeneration of tissue injuries. In this work, we show that Rigenase® exhibits a scavenging effect
toward free radicals, thus pointing to its relevant antioxidant activity
Multiwavelength Observations of the Low Metallicity Blue Compact Dwarf Galaxy SBS 0335-052
New infrared and millimeter observations from Keck, Palomar, ISO, and OVRO
and archival data from the NRAO VLA and IRAS are presented for the low
metallicity blue compact dwarf galaxy SBS 0335-052. Mid-infrared imaging shows
this young star-forming system is compact (0.31"; 80 pc) at 12.5 microns. The
large Br-gamma equivalent width (235 Angstroms) measured from integral field
spectroscopy is indicative of a ~5 Myr starburst. The central source appears to
be optically thin in emission, containing both a warm (~80 K) and a hot (~210
K) dust component, and the overall interstellar radiation field is quite
intense, about 10,000 times the intensity in the solar neighborhood. CO
emission is not detected, though the galaxy shows an extremely high global H I
gas-to-dust mass ratio, high even for blue compact dwarfs. Finally, the
galaxy's mid-infrared-to-optical and mid-to-near-infrared luminosity ratios are
quite high, whereas its far-infrared-to-radio and far-infrared-to-optical flux
ratios are surprisingly similar to what is seen in normal star-forming
galaxies. The relatively high bolometric infrared-to-radio ratio is more easily
understood in the context of such a young system with negligible nonthermal
radio continuum emission. These new lines of evidence may outline features
common to primordial galaxies found at high redshift.Comment: 28 pages including 6 figures; accepted for publication in the
Astronomical Journa
- …
