Enzyme-catalyzed preparation of chenodeoxycholic esters by an immobilized heterologous Rhizopus oryzae lipase Quintana, Paula Gabriela; Canet, Albert; Marciello, Marzia; Valero, Francisco; Palomo, José M.; Baldessari, Alicia A lipase-catalyzed preparation of ethyl and stearyl esters of chenodeoxycholic acid is described. Stearyl chenodeoxycholate is a new product and both bile acid esters were prepared through an enzymatic approach for the first time. The heterologous Rhizopus oryzae lipase, immobilized on two different supports proved to be an efficient catalyst, even more active than Candida antarctica lipase, in the esterification reaction using a complex substrate such as a bile acid. The immobilization of the enzyme on Octadecyl Sepabeads at pH 7 and 25 °C was the best choice to catalyze the esterification reaction. The influence of various reaction parameters, such as nature of the alcohol, alcohol:substrate ratio, enzyme:substrate ratio, solvent and temperature, was evaluated. Using the response surface methodology and a central composite rotatable design, the conversion of stearyl chenodeoxycholate was optimized by means of the study of the effect of enzyme:substrate ratio and alcohol:substrate ratio. The value 20 for ratios (E/S) and (A/S) was predicted as the optimal value to reach the maximum conversion. However, including economic aspects these ratios can be reduced up to 15. The well-known advantages of biocatalysis and the activity shown by the immobilized heterologous lipase make the reported procedure a convenient way to prepare chenodeoxycholic esters.

Preventive anti-inflammatory activity of an aqueous extract of larrea divaricata cav. and digestive and hematological toxicity Davicino, Roberto Carlos; Peralta, Ignacio Nahuel; Martino, Renzo Fabricio; Alonso, Rosario; Anesini, Claudia Alejandra Larrea divaricata Cav. commonly known as “jarilla hembra” is used in folklore medicine as anti-inflammatory. There was no scientific evidence justifying the medicinal use of the aqueous extract for inflammation diseases. Nowadays, there are two principal types of anti-inflammatory drugs: Steroidal anti-inflammatory drugs (corticosteroids) and non-steroidal anti-inflammatory drugs (NSAIDs), which exert gastrointestinal ulceration and bleeding. In this work the preventive anti-inflammatory activity of L. divaricata aqueous extract (AE) in C3H/He mice was determined by carrageenan- induced inflammation and ear edema tests, also its toxicity on gastric tissues and on blood cells was studied. The chromatographic profile showed: nordihydroguaiaretic acid (NDGA) as majority compound. AE exerted anti-inflammatory action without inducing gastric or blood cell toxicities. Also, it could modulate anti-inflammatory and pro-inflammatory cytokines. NDGA was not the compound responsible of the anti-inflammatory action. This work rescues the potentiality of AE as a gastric and blood cells innocuous anti-inflammatory agent and confirms its ethno- pharmacological uses.

Impacto ambiental de los remanentes de supernova Dubner, Gloria Mabel The explosion of a supernovae (SN) represents the sudden injection of about 10^51 ergs of thermal and mechanical energy in a small region of space, causing the formation of powerful shock waves that propagate through the interstellar medium at speeds of several thousands of km/s. These waves sweep, compress and heat the interstellar material that they encounter, forming the supernova remnants. Their evolution over thousands of years change forever, irreversibly, not only the physical but also the chemical properties of a vast region of space that can span hundreds of parsecs. This contribution briefly analyzes the impact of these explosions, discussing the relevance of some phenomena usually associated with SNe and their remnants in the light of recent theoreticaland observational results.

Migration of titanium dioxide microparticles and nanoparticles through the body and deposition in the gingiva: an experimental study in rats Guglielmotti, Maria Beatriz; Domingo, Mariela G.; Steimetz, Tammy; Ramos, Emilio; Paparella, María L.; Olmedo, Daniel Gustavo The aim of this experimental work was to evaluate deposition of titanium dioxide (TiO2) microparticles and nanoparticles, which could originate from titanium bioimplants, in the gingiva. Wistar rats were injected intraperitoneally (i.p.) with a suspension of TiO2 particles of different sizes (150, 10, or 5 nm). The rats were killed 12 months post-injection, and the buccal and lingual gingivae were resected and evaluated using light and scanning electron microscopy. Energy-dispersive X-ray spectroscopy (EDS) was used to confirm the presence of titanium in deposits of microparticles and nanoparticles, and the concentration of titanium in tissues was measured using inductively coupled plasma–mass spectrometry (ICP-MS). Histological examination showed that all experimental groups exhibited agglomerates, in the gingiva, of titanium particles of micrometer size range, with no associated inflammatory response. Higher concentrations of titanium traces were shown, by ICP-MS, in both buccal and lingual tissues of all experimental groups compared with their matched controls. Titanium concentrations were significantly higher in the buccal gingiva than in the lingual gingiva, and after injection with 5-nm particles than with 10-nm particles in both localizations. Titanium microparticles and nanoparticles deposit in the gingiva, and mostly on the buccal side. Gingival deposition of titanium could be considered a tissue indicator of tribocorrosion processes of titanium bioimplants.

Melanocortin 4 receptor activates ERK-cFos pathway to increase brain-derived neurotrophic factor expression in rat astrocytes and hypothalamus Ramírez, Delia; Saba, Julieta; Carniglia, Lila; Durand, Daniela Elizabeth; Lasaga, Mercedes Isabel; Caruso, Carla Mariana Melanocortins are neuropeptides with well recognized anti-inflammatory and anti-apoptotic effects in the brain. Of the five melanocortin receptors (MCR), MC4R is abundantly expressed in the brain and is the only MCR present in astrocytes. We have previously shown that MC4R activation by the α-melanocyte stimulating hormone (α-MSH) analog, NDP-MSH, increased brain-derived neurotrophic factor (BDNF) expression through the classic cAMP–Protein kinase A–cAMP responsive element binding protein pathway in rat astrocytes. Now, we examined the participation of the mitogen activated protein kinases pathway in MC4R signaling. Rat cultured astrocytes treated with NDP-MSH 1 µM for 1 h showed increased BDNF expression. Inhibition of extracellular signal-regulated kinase (ERK) and ribosomal p90 S6 kinase (RSK), an ERK substrate, but not of p38 or JNK, prevented the increase in BDNF expression induced by NDP-MSH. Activation of MC4R increased cFos expression, a target of both ERK and RSK. ERK activation by MC4R involves cAMP, phosphoinositide-3 kinase (PI3K) and the non receptor tyrosine kinase, Src. Both PI3K and Src inhibition abolished NDP-MSH-induced BDNF expression. Moreover, we found that intraperitoneal injection of α-MSH induces BDNF and MC4R expression and activates ERK and cFos in male rat hypothalamus. Our results show for the first time that MC4R-induced BDNF expression in astrocytes involves ERK-RSK-cFos pathway which is dependent on PI3K and Src, and that melanocortins induce BDNF expression and ERK-cFos activation in rat hypothalamus.

Las formas asociativas de la agricultura familiar en el desarrollo rural argentino de las últimas décadas (1990-2014); Les formes associatives de l’agriculture familiale dans le développement rural argentin des dernières décennies (1990-2014); Types of family farm association in the rural development of Argentina in recent decades (1990-2014) Lattuada, Mario Jose; Nogueira, Maria Elena; Urcola, Marcos Andres El asociativismo en el medio rural ha sido destacado históricamente como un factor que contribuyó al desarrollo de los pequeños y medianos productores agropecuarios. Desde la década de 1990 hasta la actualidad se observa una intensificación del pluralismo asociativo argentino en favor de los sectores de la agricultura familiar, con el surgimiento de cientos de nuevas asociaciones autogeneradas o promovidas por programas de desarrollo rural públicos y privados, y que a pesar de caracterizarse por la actividad cooperativa de sus integrantes no han adoptado esa forma jurídica tradicional. El objetivo de este trabajo consiste en delimitar una serie de nociones que permitan delimitar ese vasto y diversificado universo de asociaciones que identificamos como Asociaciones Económicas de la Agricultura Familiar (AEAF), construyendo, para ello, una serie de tipos ideales con el fin de proponer una herramienta para el abordaje empírico de su estudio en diferentes realidades locales, nacionales y regionales.; Les associations dans le milieu rural se sont imposées historiquement comme facteur ayant contribué au développement des petits et moyens agriculteurs et éleveurs. Depuis les années 1990 jusqu’à aujourd’hui, on observe une intensification du pluralisme associatif argentin en faveur des secteurs de l’agriculture familiale, avec l’apparition de centaines de nouvelles associations autogénérées ou promues par des programmes de développement rural publics et privés, qui, même si elles sont caractérisées par l’activité coopérative de leurs membres, n’ont pas adopté cette forme juridique traditionnelle. Ce travail vise à déterminer une série de notions permettant de délimiter ce vaste et divers milieu d’associations identifiées comme Associations Économiques de l’Agriculture Familiale (AEAF), en établissant, pour cela, une série de types idéaux pour proposer un outil d’analyse empirique de leur étude sur différentes réalités locales, nationales et régionales.; Associations in rural areas have traditionally been pointed to as a factor that contributes to the development of small and medium-sized farming. From 1990 to the present, the number of associations in Argentina has multiplied among family farms. Hundreds of new associative partnerships have emerged, self-generated or promoted by public or private rural development programs, but although they are characterized by the cooperative activity of their members, they have not adopted this traditional legal form. The objective of this paper is to outline a set of notions that define the vast and diverse universe of associations identified as Economic Associations of Family Farms (AEAF) by constructing a series of ideal types, in order to propose a tool for an empirical approach to their study in different local, national and regional situations.

Brain acetylcholine and choline concentrations and dynamics in a murine model of the Fragile X syndrome: age, sex and region-specific changes Scremin, Oscar Umberto; Roch, M.; Norman, K.; Djazayeri, S.; Liu, Y. Y. Fragile X syndrome is a learning disability caused by excess of CGG repeats in the 5′ untranslated region of the Fragile X gene (FMR1) silencing its transcription and translation. We used a murine model of this condition, Fmr1 knock-out mice (KO) to study acetylcholine (ACh) metabolism and compared it to that of wild-type control mice (WT). Brain endogenous ACh (D0ACh), free choline (D0Ch), their deuterated variants D4ACh and D4Ch and mole ratios (AChMR and ChMR) were measured by gas chromatography–mass spectrometry in the cerebral hemisphere, cerebral cortex, hippocampus and cerebellum, following D4Ch administration. Regression analysis indicated a significant decrease with age (negative slope) of D4ACh, AChMR, D4Ch and ChMR in WT mice. Age dependence was only present for D4ACh and AChMR in KO mice. Analysis of variance with age as covariate indicated a significant greater D4Ch in the cerebral cortex of KO females when compared to WT females. Contrasts between sexes within genotypes indicated lower D0Ch in cortex and cerebellum of female KO mice but not in WT and lower D4Ch in hippocampus of female KO and WT mice. In conclusion, after adjusting for age, D0ACh concentrations and synthesis from deuterium-labeled Ch were similar in KO and control WT mice in all brain regions. In contrast, significant changes in Ch dynamics were found in hippocampus and cerebral cortex of KO mice that might contribute to the pathogenesis of FXS.

Physicochemical study of the formation of complexes between pancreatic proteases and polyanions Lombardi, Julia; Picó, Guillermo Alfredo; Boeris, Valeria The formation of insoluble complexes between proteins and oppositely charged polyelectrolytes was assessed. Two pancreatic enzymes: trypsin and chymotrypsin, and two anionic synthetic polyelectrolytes: polyacrylate and polyvinylsulfonate, were used for the study at the pH range between 3.00 and 5.00. Two different titration curve shapes, representing two insoluble complexes formation mechanisms, were found. The turbidity of enzyme–polyelectrolyte mixtures is related to the increase either in the size or in the quantity of the insoluble complexes. Ionic strength destabilized insoluble complex formation. Finally, the kinetics of the process of insoluble complex formation at different conditions was studied.

La reforma penitenciaria en "el subtrópico de la república" (Tucumán, Argentina, 1881-1927); Prison reform in "the subtropics of the republic" (tucumán, argentina, 1881-1927) González Alvo, Luis Gabriel Este artículo busca contribuir al estudio de la reforma penitenciaria en Argentina entre fines del siglo XIX y principios del siglo XX, tomando como centro de su análisis a la provincia de Tucumán. Sus objetivos consisten en realizar una reconstrucción histórica del proceso de edificación de la penitenciaría, explorar los motivos que impulsaron a la clase dirigente tucumana a emprender una obra de esa envergadura a comienzos de 1880, abordar los discursos que sustentaron la reforma y profundizar sobre los modos en que esta transformación del castigo se llevó a cabo. La reforma penitenciaria, entendida como proyecto de racionalización del castigo, fue mucho más allá de la construcción de edificios especiales, ya que demandaba la creación de una infraestructura administrativa con presupuestos considerables, un gran número de personal calificado, así como una red de instituciones, conocimientos técnicos y un discurso de las ciencias sociales. Estos factores han sido estudiados en lo que respecta a Buenos Aires, pero poco se sabe de casos provinciales. Por esta razón se analizarán los orígenes de la reforma penitenciaria argentina tomando como ejemplo la primera experiencia penitenciaria en Tucumán.; This article seeks to contribute to prison reform studies in Argentina between the late nineteenth and early twentieth century, taking the example of Tucumán province. The aims of this paper are to provide an historical reconstruction of the penitentiary building process, to explore the reasons which prompted the Tucumán political class to undertake a work of this magnitude in early 1880, to analyze the speeches that supported the reform and the ways in which punishment transformation was carried out. Prison reform, understood as a punishment rationalization project, was far beyond the construction of specialized buildings, it demanded the creation of an administrative infrastructure with significant budgets, a large number of qualified staff and a network of institutions, technical knowledge and social sciences discourses. All these factors have been mostly studied for Buenos Aires penitentiary but have hardly been studied in provincial cases. For this reason, the objective of this work is to study the origins of the penitentiary reform analyzing the construction of the first penitentiary in Tucuman.

The Southern Argentina Agile Meteor Radar Orbital System (SAAMER-OS): An Initial Sporadic Meteoroid Orbital Survey in the Southern Sky Janches, D.; Close, S.; Hormaechea, Jose Luis; Swarnalingam, N.; Murphy, Adrian; O'Connor, D.; Vandepeer, B.; Fuller, B.; Fritts, D. C.; Brunini, Claudio Antonio We present an initial survey in the southern sky of the sporadic meteoroid orbital environment obtained with the Southern Argentina Agile MEteor Radar (SAAMER) Orbital System (OS), in which over three-quarters of a million orbits of dust particles were determined from 2012 January through 2015 April. SAAMER-OS is located at the southernmost tip of Argentina and is currently the only operational radar with orbit determination capabilityproviding continuous observations of the southern hemisphere. Distributions of the observed meteoroid speed, radiant, and heliocentric orbital parameters are presented, as well as those corrected by the observational biases associated with the SAAMER-OS operating parameters. The results are compared with those reported by three previous surveys performed with the Harvard Radio Meteor Project, the Advanced Meteor Orbit Radar, and theCanadian Meteor Orbit Radar, and they are in agreement with these previous studies. Weighted distributions for meteoroids above the thresholds for meteor trail electron line density, meteoroid mass, and meteoroid kineticenergyare also considered. Finally, the minimum line density and kinetic energy weighting factors are found to be very suitable for meteroid applications. The outcomes of this work show that, given SAAMER's location, the system is ideal for providing crucial data to continuously study the South Toroidal and South Apex sporadic meteoroid apparent sources.

Cambios climáticos en las sierras de Córdoba (Argentina) durante el holoceno. Aportes a las reconstrucciones climáticas a través del análisis de silicofitolitos del sitio arqueológico El Alto 3 Giorgis, Melisa Adriana; Lopez, María Laura; Rivero, Diego Eduardo; Cingolani, Ana María El análisis de silicofitolitos es una herramienta cada vez más utilizada para la reconstrucciónpaleoclimática. Sin embargo, en Córdoba estas reconstrucciones se han realizado con otras técnicas. Eneste trabajo nos propusimos calcular los índices climáticos internacionales a partir de los silicofitolitos, validar dichos índices utilizando la distribución de la vegetación y clima actual de las sierras, y presentarla primera reconstrucción paleoclimática a través de silicofitolitos para el sitio arqueológico más antiguode Córdoba. Los índices internacionales fueron consistentes con los patrones de distribución de lavegetación y clima actual, aunque el índice de frío fue más confiable y sensible que el índice de aridez.A lo largo de perfil analizado los datos de silicofitolitos indicaron un clima frío y húmedo característicodel un sitio de montaña, pero mostraron importantes variaciones en los índices de frío y aridez. Lareconstrucción climática fue consistente con los trabajos previos, al mostrar un pico de aridez al comienzodel Holoceno, seguido por un clima más húmedo y cálido que el actual, un posterior pico de mayor aridezy calor coincidente con la presencia de la familia Arecaceae y finalmente marca una disminución en latemperatura y aumento de las precipitaciones hasta la actualidad.; The analysis of silicophytoliths is an increasingly used tool for paleoclimatic reconstructions. However, in Córdoba climatic reconstruction has been performed with other techniques. In this work we aimed to calculate international climatic indices through silicophytoliths, validate these indices with the current vegetation and climate distribution in the Mountains, and present the first paleoclimatic reconstruction through silicophytoliths for the oldest archaeological site in Cordoba. The international indices were consistent with the patterns of the current vegetation and climate distribution; though the coolness index was more robust and sensitive than the aridity index. Along the analyzed profile the silicophytoliths indicated a cold and humid/wet climate, which is characteristic of a mountain site, but they showed important variation in the coolness and aridity index. The climatic reconstruction was consistent with the previous studies, since it showed a peak of aridity at the beginning of the Holocene, followed by a wetter and warmer climate than the current climate, a subsequent peak of higher aridity and warm was coincident with the presence of the Arecaceae family, and finally it showed a temperature reduction and precipitation increase until the present.

Proposal to reject the names Cestrum subsessile, Solanum ambrosiacum, S. coronatum, S. diantherum, S. jubeba, S. multiangulatum and S. perianthomega (Solanaceae) from Vellozo´s Flora Fluminensis Knapp, Sandra; Barboza, Gloria Estela; Giacomin, Leandro; Stehmann, Joao

A comprehensive assessment of mercury exposure in penguin populations throughout the Southern Hemisphere: using trophic calculations to identify sources of population-level variation Brasso, Rebecka L.; Chiaradia, André; Polito, Michael J.; Raya Rey, Andrea Nélida; Emslie, Steven D. The wide geographic distribution of penguins (Order Sphenisciformes) throughout the Southern Hemisphere provided a unique opportunity to use a single taxonomic group as biomonitors of mercury among geographically distinct marine ecosystems. Mercury concentrations were compared among ten species of penguins representing 26 geographically distinct breeding populations. Mercury concentrations were relatively low (62.00 ppm) in feathers from 18/26 populations considered. Population-level differences in trophic level explained variation in mercury concentrations among Little, King, and Gentoo penguin populations. However, Southern Rockhopper and Magellanic penguins breeding on Staten Island, Tierra del Fuego, had the highest mercury concentrations relative to their conspecifics despite foraging at a lower trophic level. The concurrent use of stable isotope and mercury data allowed us to document penguin populations at the greatest risk of exposure to harmful concentrations of mercury as a result of foraging at a high trophic level or in geographic ‘hot spots’ of mercury availability.

El Estado y las mujeres, concepciones en clave feminista; State and women, feminist conceptions key Valobra, Adriana María Pensar el Estado sigue presentando cierta urgencia en Argentina pues no ha dejado de tener una gran centralidad como interlocutor de las demandas sociales. Específi camente, procuro recuperar los aportes sustantivos de algunas pensadoras feministas. En particular, y aún a riesgo de que mi recorte pueda encasillarse en el de la colonialidad discursiva, retomaré las contribuciones de la politóloga inglesa Carole Pateman y la jurista estadounidense Catharine MacKinnon. Luego, estableceré algunas consideraciones sobre las derivaciones de sus propuestas y la forma en que otras autoras han aportado con particular eje en la ciudadanía tanto en su faz activa como pasiva. Finalmente, volveré a pensar nuestra práctica y nuestra teoría en el proceso de devenir feminista...; Sparing a thought on the State is still an urgent need in our country because the State has not lost a central place as interlocutor of social demands. Specifi cally, I try to recover the substantial contributions some feminist thinkers have made. In particular, risking that my selection could be typecast into the colonialist discursivity, I will return to the contributions of the English political scientist Carole Pateman and American lawyer Catharine MacKinnon. Then, I will make some comments on the derivations of their proposals and how other authors have contributed to debate, with special emphasis in the citizenship both active and passive. Finally, I will think about our practice and our theory in the process of becoming feminists...

The change in the enviroment of the immscible block stabilizes an unexpected HPC phase in cured block copolymer/epoxy blend Leonardi, Agustina Belen; Zucchi, Ileana Alicia; Williams, Roberto Juan Jose A conventional SAXS study of ordered phases produced in cured block copolymer (BCP)/epoxy blends with different concentrations, led to the unexpected observation of an HPC (hexagonally-packed cylinders) phase for a blend containing a 55:45 volume ratio of both domains. The BCP was polystyrene (PS, Mn = 28 kDa)-b-poly(ethylene oxide) (PEO, Mn = 11 kDa), where PS is the “epoxy-phobic” block and PEO is the “epoxy-philic” block. The epoxy formulation was based on diglycidylether of bisphenol A (DGEBA) and 4,4′-methylenebis(2,6-diethylaniline) (MDEA). A fully cured blend containing 60 wt% BCP, equivalent to 45% volume fraction of PS in the blend, exhibited an unexpected HPC morphology as supported by TEM images and SAXS spectra. The same techniques showed that a lamellar (L) phase was generated at low conversions in the same blend. The L to HPC transition was explained by the diffusion of epoxy–amine species out of the PS-rich phase with the increase in conversion. Order-order transitions in BCP/epoxy blends previously reported were explained by the partial phase separation of the miscible block from the epoxy solvent. These transitions go always in the sense of decreasing the interface curvature (e.g., from HPC to L). The transition reported in this study goes in the opposite sense (from L to HPC) and was generated by the change in environment of the immiscible block during polymerization.

SRAP as an informative molecular marker to study the Fusarium Poae genetic variability Dinolfo, María Inés; Castañares, Eliana; Stenglein, Sebastian Alberto Fusarium poae is one of the Fusarium species isolated from grains associated with Fusarium Head Blight (FHB), whose occurrence has increased in the last years. In this study, a total of 105 F. poae isolates from Argentina, Belgium, Canada, England, Finland, France, Germany, Hungary, Italy, Luxembourg, Poland, Switzerland and Uruguay were evaluated by using sequence-related amplified polymorphism (SRAP) to analyze the capacity of this molecular marker to evaluate the F. poae genetic variability. The molecular analysis showed high intraspecific variability within F. poae isolates and a partial relationship was revealed between variability and the host/geographic origin. Analysis of molecular variance (AMOVA) indicated a high genetic variability in the F. poae collection, with most of the genetic variability resulting from differences within, rather than between American and European populations. The analysis of sequenced SRAP fragments targets into hypothetical proteins from different Fusarium species showing that the SRAP technique not only allows studying F. poae genetic variability, but also targets coding regions into the F. poae genome. To our knowledge this is the first report on genetic variability of F. poae using SRAP technique and also demonstrates the efficacy of this molecular marker to amplify open reading frames in fungus.

El Fondo Argentino Sectorial (FONARSEC) anuncia los nombres de los evaluadores de la segunda comisión de la convocatoria "FITR 2013 Medio ambiente y desarrollo sustentable" mediante la Resolución de Directorio N° 266/15 del 22/07/15.

Iron cycling during the autocatalytic decomposition of benzoic acid derivatives by Fenton-like and photo-Fenton techniques Nichela, Daniela Alejandra; Donadelli, Jorge Andrés; Caram, Bruno Federico; Haddou, Menana; Rodríguez Nieto, Felipe Jorge; Oliveros,Esther; Garcia Einschlag, Fernando Sebastian In the context of our work on the oxidative degradation of a series of hydroxyl derivatives of benzoic acid (HBAs) by Fenton-like and photo-Fenton processes, we present a comprehensive study of the factors that affect the reduction of Fe(III) species, the rate limiting step in the Fenton reaction. We have investigated: (i) the formation of Fe(III)-HBA complexes, (ii) the ability of these complexes to participate in reductive pathways, and (iii) the formation of intermediate products capable of reducing ferric species.The results show that salicylate-like HBAs form stable bidentate ferric complexes in aqueous solutions at pH 3.0 and that Fe(III) complexation significantly decreases the overall degradation rates in Fenton systems by slowing down Fe(II) production through both dark and photo-initiated pathways. Interestingly, in contrast to ferric complexes of aliphatic carboxylates that undergo a photo-induced decarboxylation upon excitation in the 300-400. nm wavelength range, ferric-salicylate complexes yield Fe(II) and hydroxyl radicals by oxidation of water molecules in the coordination sphere of the metal center. However, their efficiencies are significantly lower than that of the Fe(III) aqua complex. Moreover, Fe(III)-HBA complexes are inert upon excitation of the LMCT bands involving the organic ligand (i.e., 400-600. nm).As observed for other aromatic compounds, Fe(III)-reducing intermediates formed during the Fenton oxidation of HBAs play a key role in iron cycling. The analysis of the primary oxidation/hydroxylation products as well as Fe(III)-reduction studies showed that, among dihydroxy aromatic derivatives, hydroquinone-like structures were much more efficient than catechol-like structures for reducing Fe(III). Although all trihydroxy derivatives produced Fe(II), ring opening reactions prevailed under the conditions of the Fenton reaction.The results of our investigation on the Fenton oxidation of HBA derivatives show that, in each particular case, the complex interplay of the aforementioned factors should be carefully evaluated for developing optimal applications of Fenton processes at a technological level.

Un consorcio asociativo entre el INTA, la Universidad Nacional de Luján, YPF y Conicet instalaran estaciones de medición de radiación solar en todo el territorio Nacional.

La ocupación pleistocénica de Cueva Túnel, Meseta Central de Santa Cruz: un espacio que reúne actividades en torno al procesamiento primario de presas Paunero, Rafael; Frank, Ariel David; Cueto, Manuel Enrique; Skarbun, Fabiana; Valiza Davis, Catalina En el presente trabajo buscamos articular distintos estudios que venimos realizando sobre el Componente Inferior del sitio Cueva Túnel. El mismo se ubica en la localidad arqueológica La María, Meseta Central de Santa Cruz, Argentina. Este componente fue datado en la transición Pleistoceno/holoceno. Se describen las características del paisaje donde se encuentra el sitio, considerando las evidencias de uso, las condiciones para el asentamiento y la obtención de recursos. Durante la descripción del sitio se presenta su estratigrafía, las evidencias cronológicas y las dataciones realizadas, además se sintetiza contextualmente el componente inferior. A su vez, se estudia la diversidad taxonómica de los restos faunísticos registrados y se analizan específicamente los restos de camélidos en relación con la frecuencia de partes esqueletarias, los procesos tafonómicos y las marcas antrópicas que nos informan sobre los procesos de procesamiento realizados por los grupos humanos que ocuparan el sitio. Por último, realizamos el análisis tecnomorfológico y funcional de base microscópica del conjunto lítico. Esto nos permitió discutir procesos de producción y consumo de artefactos y evaluar su articulación desde la perspectiva de la estructuración del espacio. Los resultados indican que el sitio habría funcionado principalmente como un sector de procesamiento primario de presas, dentro del marco de un circuito de movilidad regional.; This paper seeks to discuss the functionality of the Lower Component of site Cueva Túnel through the articulation of different analyses which we have been performing. This site is located in La María archaeological locality, at the Central Plateau of Santa Cruz, Argentina. The lower component is dated to the Pleistocene/Holocene transition. The characteristics of the landscape in which the site is situated are described, taking into consideration the evidence of use and the conditions for settlement and for the acquisition of resources. A contextual synthesis of the lower component is introduced and the stratigraphy, the chronological evidence and the radiocarbon dates are discussed. Besides, the taxonomic diversity of the fauna remains is analyzed. The frequency of skeletal parts, the taphonomic processes and the anthropic marks are analyzed for the chamelids remains. This data sheds light on the processing tasks made by the human groups which occupied the site. Finally, the technomorphological and functional analysis of the lithic assemblage is performed. Based on this information, the processes of production and consumption of tools are discussed. The articulation of these tasks is analyzed from a perspective which takes into account the structuration of the space. Results show that this site must have been used as a place for the primary processing of prey, within the circuit of regional mobility.