First Record of Conifer Wood from the Cañadón Asfalto Formation (Early-Middle Jurassic), Chubut Province, Argentina; Primer registro de leño de conifera de la formación cañadón asfalto (Jurásico Temprano-Medio), provincia de Chubut, Argentina Bodnar, Josefina; Escapa, Ignacio Hernán; Cúneo, Néstor Rubén; Gnaedinger, Silvia Cristina A new fossil conifer wood —Brachyoxylon currumilii sp. nov.— is described from the Lower—Middle Jurassic of Chubut Province (Argentina). The specimens were collected at a locality where the Cañadón Asfalto Formation is exposed, in the vicinity of the Cerro Cóndor village. The studied wood is characterized by mixed pitting in radial tracheid walls (predominantly uniseriate), araucarioid cross fields, low uniseriate rays and the absence of resin canals. The use of transmitted light and epifluorescence microscopy together with SEM imaging allowed the identification of additional characters such as the presence of pitting with torus-margo and compression wood. These characters are discussed in terms of their systematic relevance. On these grounds, the systematic affinity of the studied wood is discussed and linked to the extinct conifer family Cheirolepidiaceae, one of the dominant plant groups during the Jurassic and Cretaceous in Patagonia.; Se describe una nueva especie de madera fósil de conífera, Brachyoxylon currumilii sp. nov., del Jurásico Inferior a Medio de la provincia de Chubut, Argentina. Los especímenes estudiados fueron coleccionados en una localidad donde aflora la Formación Cañadón Asfalto, en las cercanías de la aldea de Cerro Cóndor. Los troncos, estudiados, se caracterizan por el punteado radial de las traqueidas de tipo mixto, predominantemente uniseriado, campos de cruzamiento de tipo araucarioide, radios uniseriados bajos y ausencia de canales resiníferos. La observación bajo MEB y microscopio con luz transmitida y epifluorescencia permitió además la identificación de caracteres tales como la presencia de torus-margo en las punteaduras y estructuras de leño de compresión. Ambos caracteres son discutidos en relación a su relevancia sistemática. Sobre esta base, se discute la afinidad sistemática de la madera estudiada, la cual posee rasgos que la vincularían con la familia de coníferas extintas Cheirolepidiaceae, uno de los grupos de plantas dominantes durante el Jurásico y Cretácico de Patagonia.

Chicken eggshell as suitable calcium source at home Brun, Lucas Ricardo Martín; Lupo, Maela; Delorenzi, Damián; Di Loreto, Verónica Elina; Rigalli, Alfredo Aim: Taken into consideration that the deficiency of calcium (Ca) in the diet is a common problem, the aim of this work was to study the chicken eggshell as Ca source at home. It was evaluated: (1) different mechanisms to process eggshells and find an easy way to determine the required amount of Ca at home and; (2) the flavor and the texture for eggshell fortified food. Methods: Chemical and mechanical methods of eggshell processing were evaluated. Changes in flavor and texture were evaluated in volunteers coordinated by a professional chef. Results: A single eggshell contains 2.07 0.18 g of Ca; therefore half an eggshell could provide the amount of Ca needed by adult human beings per day. The best way to use chicken eggshell as Ca dietary supplement is powdered to add to bread, pizza or spaghetti as there were small changes in texture and no changes in flavor.

Utilización de centros pigmentarios de Sympterygya bonapartii (Chondrichthyes Rajidae) como herramienta bioanalítica de contaminación; Use of pigmentary centers Sympterygia bonapartii (Chondrichthyes Rajidae) as a tool of pollution bioanalytical Uibrig, Román Armando; Galeano, Noelia Adelina; Schwerdt, Carla Belén; Mas, Javier Diego; Sartuqui, Javier; Guagliardo, Silvia Elizabeth; Acebal, María Florencia; Paolillo, Melisa Andrea; Tanzola, Rubén Daniel Los centros pigmentarios (CPs)se han documentado en anfibios y peces. En estos últimos, aparecen después de la primera alimentación y consisten en la acumulación de pigmentos en células fagocíticas que se asocian con sinusoides y/o centros linfoides en el bazo,el hígado y el pronefros. Han sido utilizados como bioindicadores de contaminación en los peces. La raya marmorada, Sympterygia bonapartii (Müller & Henle, 1841), es un componente habitual del estuario de Bahía Blanca, ecosistema que ha sufrido diferentes presiones de impacto ambiental a lo largo de los últimos 15 años. Se trata de un condrictio bentónico ovíparo que desova en el estuario a fines de primavera y verano. Por sus hábitos bentónicos se lo considera un buen modelo para monitorear el impacto antropogénico en el ecosistema estuarial. El objetivo principal de este estudio fue ensayar la utilización de los CPs de bazo e hígado de Sympterygia bonapartii como bioindicadores de calidad ambiental, bajo un modelo de tratamientocontrol, tomando a la Bahía San Blas como área control de referencia. Se detalló la estructura histológica de los CPs presentes en el bazo e hígado de S. bonapartii. Luego se compararon las posibles diferencias cuali y cuantitativas en los CPs debido a factores ambientales y no ambientales. Se analizaron un total de 52 ejemplares, 27 (20 hembras y 7 machos) se capturaron en el estuario de Bahía Blanca y 25 (16 hembras y 9 machos) en Bahía San Blas.; The pigments centres (CPs) have been documented in amphibious and fi sh. On these last ones, they appear after the fi rst feeding and consist in pigments accumulation of phagocytic cells that associate with sinusoid and/or lymphoid centres on spleen, liver and the pronefros. These have been used as pollution bioindicators on fi sh. The skate, Sympterygia bonapartii (Müller & Henle, 1841), is a usual specimen from Bahía Blanca’s estuary, ecosystem that has suff ered diff erent environmental impact for the past 15 years. This is a bentonic oviparous condictrius which lays eggs in the estuary at the end of spring and summer. Due its bentonic habits, it’s considered a fi ne model to monitor the men’s impact on the estuarial ecosystem. The main objective of this research was to rehearse the use of the spleen and liver’s CPs of Sympterygia bonapartii as environmental bioindicators. This was made following a model of control treatment that takes Bahía San Blas as a referential control area. The histological structure of CPs in spleen and liver of S. bonapartii was determined. After this analysis, the possible qualitative and cuantitative diff erences due to environmental or no environmental infl uences were compared. A number of 52 individuals were analyzed from which 27 (20 females and 7 males) were brought from Bahía Blanca’s estuary. The other 25 individuals (16 females and 9 males) were captured in Bahía San Blas.

La falla en la ovulación como un componente de la patogenia de la enfermedad quística ovárica bovina: rol de citoquinas Baravalle, María Eugenia; Stassi, Antonela Florencia; Velázquez, Melisa María del Luján; Belotti, Eduardo Matías; Ortega, Hugo Hector; Salvetti, Natalia Raquel La ovulación es considerada actualmente como un proceso inflamatorio agudo y a nivel local, las citoquinas cumplen papeles fundamentales debido a que influyen sobre la producción de diversos mediadores. Considerando los múltiples factores que intervienen en estos procesos (ovulación/inflamación), la alteración de uno o más componentes podría contribuir a la patogenia de enfermedades reproductivas como la enfermedad quística ovárica (COD), uno de los desórdenes reproductivos más frecuentes en el ganado bovino lechero. Esta enfermedad provoca cuantiosas pérdidas económicas para la producción pecuaria. En esta revisión, se actualizan conceptos asociados a la interacción entre el sistema inmune y los mecanismos fisiológicos responsables de la ovulación en el bovino.; Ovulation is currently considered an acute and local inflammatory process, and cytokines have fundamentals roles because they influence the production of several mediators. Considering the multiple factors involved in these processes (ovulation / inflammation), the alteration of one or more components may contribute to the pathogenesis of reproductive diseases as cystic ovarian disease (COD), one of the most common reproductive disorders in dairy cattle. This disease causes considerable economic losses for livestock. In this review, we updated concepts associated with the interaction between the immune system and the physiological mechanisms responsible of ovulation in cattle.

Ciudadanía y derechos fundamentales de las personas mayores: de las políticas gerontológicas al derecho de la vejez; Citizenship and human rights for old people: from gerontological policies to elder law Dabove, Maria Isolina En este trabajo se indaga cuáles son los problemas derivados de los paradigmas referidos a la vejez que se han empleado hasta ahora en las políticas sociales y el derecho. También se señalan los caminos que hoy requiere la perspectiva gerontológica del envejecimiento positivo. Se utilizó la metodología de las teorías integrativistas del Derecho y la Política, en las que se reconocen cuatro dimensiones de análisis: plano histórico, sociológico, normativo y valorativo. En la actual era de la globalización, la discriminación negativa por edad avanzada no logra ser revertida por la sola implementación de las políticas públicas gerontológicas. Hace falta desarrollar un modelo de ciudadanía basado en una nueva especialidad: el Derecho de la Vejez sustentado en los Derechos Humanos Fundamentales.; This paper inquires about the problems related to the aging paradigms that have been used so far in social policy and law. It also explores the paths currently required for a gerontological perspective of positive aging. Methodology used was based in integrativism theories of law and policy which recognize four dimensions of analysis: historical background, sociological, normative and evaluative. In the current era of globalization, the negative discrimination due to age cannot be reversed by the mere implementation of public gerontological policies. We need to develop a model of citizenship based on a newspecialty: Elder law supported by Human Rights.

Ni trabalenguas ni trabas en Lengua: son de los que no son… Ana, aunque crezca, no será anón Carrio, Cintia Valeria Este trabajo viene a complementar una serie de reflexiones divulgadas desde hace unos años en relación con la enseñanza de la lengua. Reflexiones que abarcan problemas tales como la concepción del objeto de enseñanza, los contenidos del área, los espacios de enseñanza de esos contenidos, la propuestas de actividades áulicas y la formación de los docentes de lengua. En esta oportunidad, retomamos estas cuestiones para revisar problemas concretos que surgen en la última etapa de la carrera del profesorado de letras y que impactan directamente en la práctica docente y, posteriormente, en el ejercicio de la profesión. Los contenidos disciplinares; la selección de esos contenidos en relación con los objetivos buscados; la secuencia epistemológica; la selección de la teoría que permite pensar el objeto; la comprensión del acto y de la acción de enseñanza del objeto; son los temas centrales que se discuten para intentar responder a los interrogantes que permiten que este artículo avance. Esto es: ¿cómo se articulan los contenidos disciplinares con los contenidos pedagógicos y didácticos?; ¿cuál es el ?obstáculo? que impide a los alumnos sostener-defender una planificación propia?; ¿por qué reina la "reproducción" por sobre la "creación"?; ¿cómo se explica el conocimiento ritual en alumnos próximos a egresar?

Pensamientos de primer orden; First order thoughts Aguilera, Mariela Uno de los argumentos en favor de la dependencia entre lenguaje y conceptos descansa en la premisa de que la posesión de conceptos involucra pensamientos de segundo orden y éstos, a su vez, requieren lenguaje. Este trabajo se centra en una variante de este argumento formulada por José Luis Bermúdez. Sostendré que aun cuando el pensamiento de segundo orden suponga competencia lingüística, no es necesario aceptar esa premisa. Propondré, en cambio, dos condiciones alternativas para la posesión de conceptos, la identificación y la generalidad. Si bien ninguna de ellas conlleva el pensamiento de segundo orden, en forma conjunta reflejan importantes aspectos del pensamiento conceptual.; One argument for the interdependence of language and concepts relies on the assumption that concept possession involves second order thoughts, which in turn are language dependent. This paper focuses on a recent version of this argument formulated by José Luis Bermúdez. It claims that even though second order thought involves linguistic competence, the above assumption is not compelling. Instead, two different conditions for concept possession are proposed, identification and generality. Although none of them involves second order thought, together they highlight important features of conceptual thinking.

Epigenetics of Insulin Resistance: An Emerging Field in Translational Medicine Sookoian, Silvia Cristina; Pirola, Carlos Jose In this article, we review the current knowledge of and recent insights into the role of epigenetic factors in the development of insulin resistance (IR), with emphasis on peroxisome proliferator-activated receptor gamma coactivator 1α (PPARGC1A or PGC1α) methylation on fetal programming and liver modulation of glucose-related phenotypes. We discuss the pathogenesis of IR beyond the integrity of β-cell function and illustrate the novel concept of mitochondrial epigenetics to explain the pathobiology of metabolic-syndrome-related phenotypes. Moreover, we discuss whether epigenetic marks in genes of the circadian rhythm system are able to modulate insulin/glucose-related metabolic functions and place hypoxia inducible factor 1 α (HIF1α) as a part of the master CLOCK gene/protein interaction network that might modulate IR. Finally, we highlight relevant information about epigenetic marks and IR so that clinicians practicing in the community may envision future areas of medical intervention and predict putative biomarkers for early disease detection.

Maritrema orensense and Maritrema bonaerense (Digenea: Microphallidae): descriptions, life cycles, and comparative morphometric analyses Alda, Maria del Pilar; Bonel, Nicolás; Hechinger, Ryan F.; Martorelli, Sergio Roberto We elucidate the life cycle of Maritrema orensense for the first time and experimentally confirm that of the sympatric Maritrema bonaerense. In Argentinean estuaries, both species parasitize the cochliopid snail Heleobia australis as first intermediate host, the grapsid crabs Neohelice granulata and Cyrtograpsus angulatus as second intermediate hosts, and gulls as definitive hosts. Here, we describe the daughter sporocysts and cercariae of M. orensense and redescribe these stages for M. bonaerense. Sporocysts of M. orensense are shorter, with fewer developed cercariae than M. bonaerense. The cercariae of M. orensense have longer, larger, and more undulating cephalic glands than M. bonaerense. We redescribe metacercariae and adults of both species and compare them with the previous descriptions. Intestinal ceca length, vitellaria shape and extension, and egg size are the most relevant characteristics in metacercariae and adults for differentiating the species. Hence, the detailed morphological description and comparative analyses of morphometrics obtained from natural and experimental infections permit clear differentiation of M. orensense and M. bonaerense at each life stage.

La democracia Argentina entre "el miedo" y "la esperanza". Apuntes sobre el lugar del cuerpo y las emociones en los procesos políticos. Lisdero, Pedro Matías Nos proponemos pensar la relación entre cuerpos-emociones e instituciones políticas. Para ello, exploramos brevemente un caso puntual (el terrorismo de estado en Argentina) como vía para comprender cómo operan ciertas emociones sociales (miedo-culpa-resignación), construidas históricamente, en tanto condiciones (posibles) de la experiencia política.

A Distinct Tetradentate N2O2-type Ligand: (o-Carboranyl)bis(2- hydroxymethyl)pyridine Di Salvo, Florencia; Teixidor, Francesc ; Viñas, Clara ; Giner Planas, José A new chiral racemic ligand (o-carboranyl)bis(2-hydroxymethyl) pyridine oCB(hmpH)2, that is composed of a central o-carborane unit where two arms radiate out of the cluster carbons each one containing a 2-pyridylmethylalcohol chelating arms, provides two potentially bidentate {NO} or one tetradentate {N2O2} binding pockets. An unprecedented octahedral CoII complex CoCl2(antioCB( hmpH)2] was obtained under aerobic conditions and characterized by X-ray crystallography as well as IR and NMR spectroscopy. anti-oCB(hmpH)2 acts as a tetradentate N2O2-ligand affording the complex as a racemic mixture of cis-alpha-DELTA-[CoCl2(RR-antioCB(hmpH)2)] and LAMBDA-[CoCl2(SS-anti-oCB(hmpH)2)]. The new ligand oCB(hmpH)2 appears to be suitable for producing a variety of new chiral-at-metal complexes.

Curcumin/Gd Loaded Apoferritin: A Novel "Theranostic" Agent To Prevent Hepatocellular Damage in Toxic Induced Acute Hepatitis Cutrin, Juan Carlos; Geninatti Crich, Simonetta; Burghelea, Diana; Dastrù, Walter; Aime, Silvio Apoferritin has been exploited to deliver simultaneously therapeutic and imaging agents (loaded into its internal cavity) to hepatocytes as this protein is efficiently taken up from blood by hepatocyte scavenger receptor class A type 5 via the ferritin transporting route. To this purpose the protein has been loaded with the magnetic resonance imaging (MRI) contrast agent GdHPDO3A and curcumin, a polyphenolic substance endowed with multiple pharmacological actions, namely: antioxidant, anti-inflammatory, antineoplastic. Curcumin and GdHPDO3A loaded apoferritin has been used with the aim to attenuate the thioacetamide-induced hepatitis together with the evaluation by MRI of drug delivery efficiency. Mice pretreated by intraperitoneal administration showed significantly attenuated hepatic injury as assessed by measuring alanine aminotransferase (ALT) activity in plasma and by histology assessment. The encapsulation of curcumin inside the apoferritin cavity significantly increases its stability and bioavailability while maintaining its therapeutic anti-inflammatory properties.

A re-evaluation of morphological characters of the invasive ascidian Corella eumyota reveals two different species at the tip of South America and in the South Shetland Islands, Antarctica Alurralde, Roque Gastón; Torre, Luciana; Schwindt, Evangelina; Castilla, Juan C.; Tatian, Marcos The native solitary ascidian Corella eumyota Traustedt, 1882) is commonly found in the Southern Hemisphere in the cold-temperate waters of the Subantarctic and Antarctic regions. Its recent spread into the Northern Hemisphere throughout the NE Atlantic gave the species the status of invasive. Together with its widespread distribution, reports on its wide variability (several distinct morphological characters, genetic discontinuities and also possible misidentifications) cast doubt on the taxonomic status of different populations of this species. This work, based on the observation, quantification and analysis of specific morphological characters in specimens collected at five different localities of South America and Antarctica, strongly indicates that there are two different species: C. eumyota from South America and Corella antarctica Sluiter, 1905) from Antarctica, which has been till now considered a junior synonym of the former. The species clearly differ in the arrangement of the gonadal ducts, the size of the larvae and the shape of the anus, among other characters. Morphological variation displays a defined, discrete grouping supporting a clear differentiation into two species. This result shows the need for careful inspection of specimens to avoid wrong interpretations in a context of changes of marine biota due to biological invasions.

Biofilm Inhibition of Spoilage Bacteria by Argentinean Fruit Juices with Antihypertensive Activity Vallejo, Claudia Veronica; Aredes Fernández, Pedro Adrián; Farias, Marta Elena; Rodriguez Vaquero, Maria Jose Argentinean juices have been studied for their antihypertensive activity, the inhibition of bacteria biofilm formation and the effect on the viability of wine yeast. The influence of phenolic compounds on these activities was evaluated. These studies are the first step for the development of a new type of wine that includes grape must supplement with fruit juices with antihypertensive effect. All juices posses a high antihypertensive activity, higher than 50%. Strawberry juices and eureka lemon showed the highest activity, whereas clarified juices posses the lowest activity. All studied juices produce a high inhibition of bacteria biofilm formation, and the strawberry, orange and mandarin varieties not affect the growth or viability of yeast. Our results permit to conclude that it could be possible the use of these juices in a new type of wine or as a source of new antihypertensive agents for pharmaceutical industry.

First record of gastroliths associated with elasmosaur remains from La Colonia Formation (CampanianeMaastrichtian), Chubut, Patagonia Argentina, with comments on the probable depositional palaeoenvironment of the source of the gastroliths O'gorman, Jose Patricio; Salgado, Leonardo; Cerda, Ignacio Alejandro; Gasparini, Zulma A gastrolith set, comprising 197 elements, associated with an indeterminate elasmosaurid plesiosaur collected from the CampanianeMaastrichtian La Colonia Formation, Chubut, Argentina, is described. Most of the gastroliths are discoidal (41.9%) or spheroidal (34.8%), with a mean Maximum Projection Sphericity Index value of 0.69 and a mean OP Index value of 0.74. The values of these indices are compared with those recorded for gastroliths associated with other Upper Cretaceous elasmosaurids to see if patterns with palaeobiological relevance are evident. The mean values of the Maximum Projection Sphericity Index and the Oblate-Prolate Index allow us to infer a fluvial or estuarine origin for all the elasmosaurid gastroliths for which these indices have been calculated. This inference is palaeobiologically informative because it indicates that at least some Upper Cretaceous elasmosaurs entered into estuarine (or fluvial) environments. It also helps explain the interesting vertebrate assemblage of the Allen and La Colonia formations where a rich continental fauna is recorded but elasmosaurids and polycotylids are the only well represented vertebrates with marine affinities.

El Estatuto del Servicio Doméstico y sus antecedentes: debates en torno a la regulación del trabajo doméstico remunerado en la Argentina Tizziani, Ania Pese a ser una de las principales formas de empleo femenino urbano, el servicio doméstico representa, en Argentina, una de las actividades más relegadas, tanto en términos de las condiciones de trabajo como de su marco regulatorio. Las trabajadoras domésticas son una de las últimas categorías que se incorporan en las instituciones de protección social y al derecho laboral, a través del llamado "Estatuto del Servicio Doméstico", dictado en 1956, que es el que aún está en vigencia. Existen, sin embargo, algunos antecedentes de regulaciones referidas a esta ocupación. El antecedente más importante está constituido por un proyecto de ley elaborado por una legisladora del partido peronista, que fue debatido y aprobado en la cámara de diputados en septiembre de 1955. Nos interesa, en este artículo, analizar este proceso de incorporación del trabajo doméstico remunerado dentro del derecho laboral a través de la puesta en diálogo de estas dos iniciativas. El objetivo es estudiar algunas de las tensiones a las que dio lugar la regulación del servicio doméstico, que están atravesadas por problemáticas más globales que conciernen el trabajo de las mujeres, los roles femeninos tradicionales y las relaciones de género y clase.; Despite being one of the main female occupations, domestic service represents, in Argentina, one of the most neglected, both in terms of working conditions and its regulatory framework. Domestic workers are one of the last categories that are incorporated in the institutions of social protection and labor law, through the Estatuto del Servicio Doméstico, enacted in 1956. There are, however, some previous regulations related to this occupation. The most important antecedent consists of a project presented by a legislator of the Peronist party, in September 1955. In this paper, we analyze the process of incorporation of paid domestic work within the labor law through the comparison of these two initiatives. The aim is to study some of the tensions originated by this regulation, which are crossed by more global issues concerning women's work, traditional female roles and gender and class relations.

First description of natural Ehrlichia canis and Anaplasma platys infections in dogs from Argentina Eiras, Diego Fernando; Craviotto, María Belén; Vezzani, Dario; Eyal, Osnat; Baneth, Gad Bacteria belonging to the Anaplasmataceae family are vector transmitted agents that affect a variety of vertebrate hosts including the tick-borne pathogens Ehrlichia canis and Anaplasma platys, which cause canine monocytic ehrlichiosis and cyclic thrombocytopenia, respectively. These two infections, typically reported from tropical and sub-tropical regions, have not been previously reported in dogs from Argentina. A total of 86 blood samples from dogs with suspected rickettsial disease and 28 non-suspected dogs were studied. Analysis included evaluation of hematological findings, PCR for Ehrlichia and Anaplasma species and sequencing of the positive PCR products. E. canis was detected in the blood of six dogs and A. platys in eighteen. All the dogs categorized as non-suspected were negative by PCR. Co-infection with Hepatozoon canis and Babesia vogeli was documented. This first report of E. canis and A. platys infections in dogs from Argentina indicates that these tick-borne infections have a considerably broader range than previously recognized in South America.

Silver deposition on polypyrrole films electrosynthesized in salicylate solutions González, Belén; Brugnoni, Lorena Inés; Vela, Maria Elena; Saidman, Silvana Beatriz This work is a study of the immobilization of silver species in polypyrrole films electrosynthesized in salicylate solutions. The obtained coatings were characterized by electrochemical and surface analysis techniques. It is proposed that the presence of salicylate in the polymer plays a crucial role in allowing the inmobilization of silver species. The modified electrode presents antibacterial activity against Gram-positive bacteria Staphylococcus aureus.

Cerebellar Stroke Impairs Executive Functions But Not Theory of Mind Roca, María; Gleichgerrcht, Ezequiel; Ibáñez Barassi, Agustín Mariano; Torralva, Teresa; Manes, Facundo Francisco Even though cerebellar activation has been described during theory of mind (ToM) tasks in neuroimaging studies, no previous studies have investigated ToM in group of patients with cerebellar strokes. In the present study we assessed 11 patients with cerebellar infarction on a variety of executive tests and with the Faux Pas test of ToM. Even if cerebellar patients showed significant deficits on executive tasks relative to a control group, no significant differences were found between the groups on the Faux Pas test. This is the first group study to demonstrate that focal cerebellar lesions don't affect ToM.

Techniques for Measuring Aerosols using the Central Laser Facility at the Pierre Auger Observatory Abreu, P.; Aglietta, M.; Ahlers, M.; Ahn, E. J.; Albuquerque, I. F. M.; Allekotte, Ingomar; Almela, Daniel Alejandro; Asorey, Hernán Gonzalo; Ávila, G.; Bertou, Xavier Pierre Louis; Dasso, Sergio Ricardo; de la Vega, Gonzalo Andrés; Dova, Maria Teresa; Etchegoyen, Alberto; Figueira, Juan Manuel; Filevich, Alberto; Gamarra, R. F.; Fuster, Alan Ezequiel; Garcia, Beatriz Elena; Gitto, J.; Golup, Geraldina Tamara; Gómez Albarracín, Flavia Alejandra; Gomez Berisso, Mariano; Gómez Vitale, P. F.; Guardincerri, Yann; Hampel, Matias Rolf; Hansen, Patricia Maria; Harari, Diego Dario; Jarne, Cecilia Gisele; Josebachuili Ogando, Mariela Gisele; Kleinfeller, J.; Mariazzi, Analisa Gabriela; Marin, J.; Masías Meza, Jimmy Joel; Melo, Diego Gabriel; Micheletti, Maria Isabel; Mollerach, Maria Silvia; Moreno, Juan Cruz; Pallotta, Juan Vicente; Piegaia, Ricardo Nestor; Pieroni, Pablo Emanuel; Platino, Manuel; Ponce, Victor Hugo; Quel, Eduardo Jaime; Ravignani Guerrero, Diego; Ristori, J.; Rodriguez Martino, Julio César; Rodriguez Rojo, J.; Roulet, Esteban; Rovero, Adrian Carlos; Sanchez, Federico Andrés; Sato, R.; Schröder, F. G.; Sciutto, Sergio Juan; Sidelnik, Iván Pedro; Suarez, Federico; Squartini, R.; Supanitsky, Alberto Daniel; Tapia Casanova, Alex Marcelo; Tiffenberg, Javier Sebastian; Wahlberg, Hernan Pablo; Wainberg, Oscar Isaac; Wundheiler, Brian; Zepeda, A.; Zhou, J.; Zhu, Y.; Zimbres Silva, M.; Ziolkowski, M. The Pierre Auger Observatory in Malargüe, Argentina, is designed to study the properties of ultra-high energy cosmic rays with energies above 1018eV. It is a hybrid facility that employs a Fluorescence Detector to perform nearly calorimetric measurements of Extensive Air Shower energies. To obtain reliable calorimetric information from the FD, the atmospheric conditions at the observatory need to be continuously monitored during data acquisition. In particular, light attenuation due to aerosols is an important atmospheric correction. The aerosol concentration is highly variable, so that the aerosol attenuation needs to be evaluated hourly. We use light from the Central Laser Facility, located near the center of the observatory site, having an optical signature comparable to that of the highest energy showers detected by the FD. This paper presents two procedures developed to retrieve the aerosol attenuation of fluorescence light from CLF laser shots. Cross checks between the two methods demonstrate that results from both analyses are compatible, and that the uncertainties are well understood. The measurements of the aerosol attenuation provided by the two procedures are currently used at the Pierre Auger Observatory to reconstruct air shower data.