Acidic preconditioning of endothelial colony-forming cells (ECFC) promote vasculogenesis under proinflammatory and high glucose conditions in vitro and in vivo Mena, Hebe Agustina; Zubiry, Paula Romina; Dizier, Blandine; Schattner, Mirta Ana; Boisson Vidal, Catherine; Negrotto, Soledad Background: We have previously demonstrated that acidic preconditioning of human endothelial colony-forming cells (ECFC) increased proliferation, migration, and tubulogenesis in vitro, and increased their regenerative potential in a murine model of hind limb ischemia without baseline disease. We now analyze whether this strategy is also effective under adverse conditions for vasculogenesis, such as the presence of ischemia-related toxic molecules or diabetes, one of the main target diseases for cell therapy due to their well-known healing impairments. Methods: Cord blood-derived CD34 + cells were seeded in endothelial growth culture medium (EGM2) and ECFC colonies were obtained after 14-21 days. ECFC were exposed at pH 6.6 (preconditioned) or pH 7.4 (nonpreconditioned) for 6 h, and then pH was restored at 7.4. A model of type 2 diabetes induced by a high-fat and high-sucrose diet was developed in nude mice and hind limb ischemia was induced in these animals by femoral artery ligation. A P value < 0.05 was considered statistically significant (by one-way analysis of variance). Results: We found that acidic preconditioning increased ECFC adhesion and the release of pro-angiogenic molecules, and protected ECFC from the cytotoxic effects of monosodium urate crystals, histones, and tumor necrosis factor (TNF)α, which induced necrosis, pyroptosis, and apoptosis, respectively. Noncytotoxic concentrations of high glucose, TNFα, or their combination reduced ECFC proliferation, stromal cell-derived factor (SDF)1-driven migration, and tubule formation on a basement membrane matrix, whereas almost no inhibition was observed in preconditioned ECFC. In type 2 diabetic mice, intravenous administration of preconditioned ECFC significantly induced blood flow recovery at the ischemic limb as measured by Doppler, compared with the phosphate-buffered saline (PBS) and nonpreconditioned ECFC groups. Moreover, the histologic analysis of gastrocnemius muscles showed an increased vascular density and reduced signs of inflammation in the animals receiving preconditioned ECFC. Conclusions: Acidic preconditioning improved ECFC survival and angiogenic activity in the presence of proinflammatory and damage signals present in the ischemic milieu, even under high glucose conditions, and increased their therapeutic potential for postischemia tissue regeneration in a murine model of type 2 diabetes. Collectively, our data suggest that acidic preconditioning of ECFC is a simple and inexpensive strategy to improve the effectiveness of cell transplantation in diabetes, where tissue repair is highly compromised.

Deep time diversity of metatherian mammals: Implications for evolutionary history and fossil-record quality Bennett, C. Verity; Upchurch, Paul; Goin, Francisco Javier; Goswami, Anjadi Despite a global fossil record, Metatheria are now largely restricted to Australasia and South America. Most metatherian paleodiversity studies to date are limited to particular subclades, time intervals, and/or regions, and few consider uneven sampling. Here, we present a comprehensive new data set on metatherian fossil occurrences (Barremian to end Pliocene). These data are analyzed using standard rarefaction and shareholder quorum subsampling (including a new protocol for handling Lagerstätte-like localities). Global metatherian diversity was lowest during the Cretaceous, and increased sharply in the Paleocene, when the South American record begins. Global and South American diversity rose in the early Eocene then fell in the late Eocene, in contrast to the North American pattern. In the Oligocene, diversity declined in the Americas, but this was more than offset by Oligocene radiations in Australia. Diversity continued to decrease in Laurasia, with final representatives in North America (excluding the later entry of Didelphis virginiana) and Europe in the early Miocene, and Asia in the middle Miocene. Global metatherian diversity appears to have peaked in the early Miocene, especially in Australia. Following a trough in the late Miocene, the Pliocene saw another increase in global diversity. By this time, metatherian biogeographic distribution had essentially contracted to that of today. Comparison of the raw and sampling-corrected diversity estimates, coupled with evaluation of "coverage" and number of prolific sites, demonstrates that the metatherian fossil record is spatially and temporally extremely patchy. Therefore, assessments of macroevolutionary patterns based on the raw fossil record (as in most previous studies) are inadvisable.

El poder simbólico de la UNESCO en América Latina. Sobre el vínculo FLACSO-UNESCO; O poder simbólico da UNESCO na América Latina sobre a ligação FLACSO-UNESCO; UNESCO symbolic power in Latin America about the link FLASCO-UNESCO; Le pouvoir symbolique de l’UNESCO en Amerique Latine sur le lien FLACSO-UNESCO Abarzúa Cutroni, Anabella Carolina Nuestras pesquisas indican que la UNESCO ha sido históricamente una Organización de alto impacto a nivel simbólico. El patrocinio de esta Organización de la ONU a determinadas iniciativas científicas, educativas y culturales no se llevó a cabo sólo mediante financiamiento, la contratación de expertos y el otorgamiento de becas sino que implicó también el aval, el crédito simbólico, de una organización internacional. Observar este fenómeno es precisamente el objetivo del presente artículo. Para esto tomamos el caso de un patrocinio emblemático que la UNESCO desarrolló en América Latina desde fines de la década de 1950: la creación y sostenimiento de la Facultad Latinoamericana de Ciencias Sociales (FLACSO).; Nossas pesquisas sugerem que a Unesco historicamente teve um grande impacto a nível simbólico. O patrocínio das iniciativas científicas, educacionais e culturais específicas da Organização das Nações Unidas realizada não só através de financiamento, a contratação de especialistas e bolsas de estudo, mas também envolveu o crédito simbólico de uma organização internacional. O objetivo deste artigo é observar este fenômeno. Para isso, nos tomamos o caso de um patrocínio porta-estandarte da Unesco desenvolvido na América Latina desde o final dos anos 1950: a criação e o apoio da Faculdade Latino-Americana de Ciências Sociais (Flacso).; Our research indicates that, historically, Unesco had been an Organization of high impact in a symbolic level. The support from this Organization of the UN to sciences, educations and cultural initiatives implies funds, experts, fellowships and, the most important, the symbolic credit of an international organization. The objective of this paper is to analyze that. Then we study an emblematic support of Unesco in Latin America: la creation and sustenance of the Latin American Faculty of Social Science (Flacso) since 1950 decade.; Notre recherche suggère que l'Unesco a toujours eu une forte incidence sur le plan symbolique. Le parrainage des initiatives scientifiques, éducatives et culturelles spécifiques Organisation des Nations Unies réalisée non seulement par le financement, le recrutement d'experts et des bourses, mais aussi impliqué le crédit symbolique d'une organisation internationale. L’objectif de cet article est d'observer ce phénomène. Pour cela, nous prenons le cas d'un parrainage de repère, l'Unesco a développé en Amérique latine depuis la fin des années 1950: la création et le soutien de la Faculté latino-américaine de sciences sociales (Flacso).

Characterization of an Air-Based Coaxial Dielectric Barrier Discharge Plasma Source for Biofilm Eradication Soler Arango, Juliana; Brelles Mariño, Graciela; Rodero, Antonio; Garcia, Maria Air-based atmospheric-pressure cold plasmas are a source of charged particles, excited species, radicals, and UV rays, known to induce degradation of biomaterials. In this work we characterize an air-based Dielectric Barrier Discharge plasma source designed for biofilm eradication, and study plasmas generated under different conditions by Optical Emission Spectroscopy. The main excited species in air-based plasmas are N2 (C3Πu) molecules and the gas temperatures never exceed 335 K, decreasing as air amounts increase in the feeding gas. Excited oxygen atoms and OH species are only detected in discharges generated in argon-containing gases. The temperature of the effluent remains below 308 K. Air-based plasmas are useful for biofilm eradication as they produce high amounts of ozone at a low gas temperature.

Multiculturalidad y derechos humanos: Nuevas perspectivas para la construcción del discurso sobre los derechos humanos Bonet de Viola, Ana María Este trabajo aborda la cuestión de la vigencia y adaptación de los discursos clásicos-liberales sobre los derechos humanos en el contexto de multiculturalidad de la comunidad global. MetodológicamenteSe utiliza un un enfoque genealógico, que, a partir de la crisis de la teoría clásica sobre los Derechos Humanos, fundada en la lógica de la identidad, pretende rastrear alternativas discursivas diferentes en gestación, en vistas a una re-construcción pluralista del sistema de Derechos Humanos. Este recorrido se llevará a cabo a través del abordaje de las crisis de los postulados universalistas, laicistas y liberales, que constituyen los principales ejes críticos que perfilan el debate actual en la materia. De esta manera, se propone analizar este proceso de transformación discursiva, que define la arena jurídica para el desarrollo venidero en materia de Derechos Humanos, poniendo de relieve el potencial de los discursos de la diferencia para la superación de las crisis generadas a partir de la lógica individualista de la identidad.

¿Quiénes se fueron?: Aproximaciones a los motivos de abandono de un programa de apuntalamiento a las trayectorias educativas de estudiantes universitarios; Who dropped out?: An approach to the reasons why higher education students abandoned a socio- educational program to support their educational paths Mayer, Liliana Judith; Cerezo, Leticia La masificación universitaria, que conlleva un incremento en la cantidad de ingresantes a las universidades, plantea situaciones novedosas a ese nivel educativo en términos de composición social del estudiantado. Distintos intentos de dar respuesta a esas problemáticas han surgido, algunos de ellos, provenientes de organizaciones de la sociedad civil. En el presente artículo presentamos los resultados de parte de una evaluación de un programa educativo de apuntalamiento a la trayectoria universitaria de jóvenes provenientes de sectores vulnerables de Argentina. Específicamente, abordamos los motivos aducidos por aquellas personas “ex – participantes” para concluir su incursión en el Programa. Con este objetivo se desplegó una investigación cuya estrategia metodológica fue cualitativa y constó de la realización de 15 entrevistas en profundidad a jóvenes que dejaron de formar parte del programa evaluado. Con el fin de dar cuenta de los repertorios que explican la salida del Programa de los “ex becarios”, se los dividió en dos grandes grupos: quienes salieron del Programa por sugerencia de las organizaciones de la sociedad civil que lo gestionan, y a través de las cuales se materializaba su adhesión a la estrategia; y quienes se “salieron” por iniciativa propia. La investigación da cuenta de tendencias actuales para las trayectorias universitarias, que combinan periodos de abandono con la promesa —muchas veces cumplida—de continuar los estudios, y la necesidad de compatibilizar el estudio con el trabajo.; Higher education massification process implies, by definition, an increase in enrollment rates. Furthermore, it brings new situations in terms of the social composition of the student body. In the intent of giving responses to the new problematics that these changes suppose, there have been implemented –and still aredifferent initiatives, related to higher education inclusion. Though most of them are State initiatives, in a smaller amount, others came from NGOs. In the following article, we present part of the results of a socio- educational Program evaluation that supports higher educational paths for underprivileged students in Argentina. Specifically, for this article, we will analyze the reasons that beneficiaries of that program, drop out of it. The analysis is based on a qualitative methodology which consisted on 15 in depth interviews to scholars who quitted the Program, inquiring both who “decided” to drop out and those who were asked to do so by the Program authorities. This research shows current trends in educational paths, which combine periods of dropping out, with the promise of – many times already accomplished- going back to university. Also, the need to make compatible studies and work.

Incorporación a la currícula de una metodología para la degradación de cianuros Laurenti, Rocío Belén; Lottersberger, Javier; Macagno, Julio Cesar; Kergaravat, Silvina Vanesa El propósito de este trabajo fue evaluar el proceso enseñanza-aprendizaje de los alumnos de la carrera de Licenciatura en Saneamiento Ambiental frente a, la incorporación dentro de la asignatura de Química Ambiental, de un trabajo experimental en el laboratorio. Este trabajo consistió en el estudio de la degradación de un contaminante que actualmente está afectando una región de nuestro país, como es el cianuro, a partir de derrames hacia vertientes de agua que se han producido en una minera en San Juan. Para llevar a cabo esta incorporación se utilizaron estrategias expositivas y un trabajo experimental en el laboratorio, con la posterior evaluación del material generado por parte de los alumnos a partir de preguntas contenidas en una encuesta. Los resultados de la misma revelaron que, la incorporación de esta actividad, generó conciencia por parte de los alumnos de la importancia de la evaluación y control de la calidad del agua de consumo humano, el conocimiento de técnicas para lograr la degradación de un contaminante, con la posible remediación de un daño ocasionado, y el aprendizaje de como informar e interpretar los resultados.

Green synthesis of silver nanoparticles aimed at improving theranostics Vedelago, José Alberto; Gomez, Cesar Gerardo; Valente, Mauro Andres; Mattea, Facundo Nowadays, the combination of diagnosis and therapy, known as theranostics, is one of the keys for an optimal treatment for cancer diseases. Theranostics can be significantly improved by incorporating metallic nanoparticles that are specifically delivered and accumulated in cancerous tissue. In this context, precise knowledge about dosimetric effects in nanoparticle-infused tissues as well as the detection and processing of emerging radiation are extremely important issues. In the last years the first studies on theranostic nanomaterials in gel dosimetry have been presented but there is still a broad field of study to explore. Most of gel dosimetric materials are extremely sensible to modifications in their composition, the addition of enhancers, metallic or inorganic charges can alter their stability and dosimetric properties; therefore, thorough studies must be made before the incorporation of any type of modifier. In this work, the synthesis of metallic nanoparticles suitable for gel dosimetry for x-ray applications is presented. A green synthesis process of silver nanoparticles coated with porcine skin gelatin by thermal reduction of silver nitrate is presented. Nanoparticles were obtained and purified for their application in gel dosimetry. Also, nanoparticles size distribution, reaction yield and the preliminar application as theranostic agents were tested in Fricke gel dosimetry in the keV range. The obtained nanoparticles were successfully used in theranostic applications acting as fluorescent agents and dose enhancers in X-ray beam irradiation simultaneously.

Synthesis and Encapsulation of bis-eugenol in a Mesoporous Solid Material: Enhancement of the Antioxidant Activity of a Natural Compound from Clove Oil Guntero, Vanina Alejandra; Ferretti, Cristián Alejandro; Mancini, Pedro Maximo Emilio; Kneeteman, Maria Nelida In the present work, microwave extraction conditions to recover high eugenol content in the crude extract from clove were investigated. The effect of factors like temperature, stirring, time, liquid: Solid ratio and solutions of solvent were evaluated with Taguchi?s method. The eugenol content was determined by gas chromatography. From the isolated eugenol, the bis-phenol was synthesized by the dimerization of eugenol. The encapsulation of bis-eugenol on the mesoporous silica was carried out by a microwave assisted process. Previously, mesoporous silica SBA-15 was prepared by hydrothermal synthesis using Pluronic P123 triblock copolymer as a surfactant. The bis-eugenol encapsulated in SBA-15 was characterized by physicochemical techniques. The results indicated that the encapsulation of bis-eugenol in the pores of silica occurred through weak interactions of an electrostatic nature without producing chemical changes in the antioxidant property. The antioxidative activity of eugenol, bis-eugenol and bis-eugenol/SBA-15 system was examined by phosphomolybdenum assay. Among these materials, a remarkably high antioxidant activity was found in bis-eugenol encapsulated in SBA-15. These resultas suggest the possibility of applying this system as an antioxidant active packaging in the future.

Consensus guidelines for the use and interpretation of angiogenesis assays Nowak Sliwinska, Patrycja; Alitalo, Kari; Allen, Elizabeth; Anisimov, Andrey; Aplin, Alfred C.; Auerbach, Robert; Augustin, Hellmut G.; Bates, David O.; Beijnum, Judy R. van; Bender, R. Hugh F.; Bergers, Gabriele; Bikfalvi, Andreas; Bischoff, Joyce; Böck, Barbara C.; Brooks, Peter C.; Bussolino, Federico; Cakir, Bertan; Carmeliet, Peter; Castranova, Daniel; Cimpean, Anca M.; Cleaver, Ondine; Coukos, George; Davis, George E.; De Palma, Michele; Dimberg, Anna; Dings, Ruud P. M.; Djonov, Valentin; Dudley, Andrew C.; Dufton, Neil P.; Fendt, Sarah-Maria; Ferrara, Napoleone; Fruttiger, Marcus; Fukumura, Dai; Ghesquière, Bart; Gong, Yan; Griffin, Robert J.; Harris, Adrian L.; Hughes, Christopher C. W.; Hultgren, Nan W.; Iruela-Arispe, M. Luisa; Irving, Melita; Maidana, Agostina Jainen; Kalluri, Raghu; Kalucka, Joanna; Kerbel, Robert S.; Kitajewski, Jan; Klaassen, Ingeborg; Kleinmann, Hynda K.; Koolwijk, Pieter; Kuczynski, Elisabeth; Kwak, Brenda R.; Koen, Marien; Melero Martin, Juan M.; Munn, Lance L.; Nicosia, Roberto F.; Noel, Agnes; Nurro, Jussi; Olsson, Anna-Karin; Petrova, Tatiana V.; Pietras, Kristian; Pili, Roberto; Pollard, Jeffrey W.; Post, Mark J.; Quax, Paul H. A.; Rabinovich, Gabriel Adrián; Raica, Marius; Randi, Anna M.; Ribatti, Domenico; Ruegg, Curzio; Schlingemann, Reinier O.; Schulte Merker, Stefan; Smith, Lois E. H.; Song, Jonathan W.; Stacker, Steven A.; Stalin, Jimmy; Stratman, Amber N.; Van de Velde, Maureen; van Hinsbergh, Victor W. M.; Vermeulen, Peter B.; Waltenberger, Johannes; Weinstein, Brant M.; Xin, Hong; Yetkin Arik, Bahar; Yla Herttuala, Seppo; Yoder, Mervin C.; Griffioen, Arjan W. The formation of new blood vessels, or angiogenesis, is a complex process that plays important roles in growth and development, tissue and organ regeneration, as well as numerous pathological conditions. Angiogenesis undergoes multiple discrete steps that can be individually evaluated and quantified by a large number of bioassays. These independent assessments hold advantages but also have limitations. This article describes in vivo, ex vivo, and in vitro bioassays that are available for the evaluation of angiogenesis and highlights critical aspects that are relevant for their execution and proper interpretation. As such, this collaborative work is the first edition of consensus guidelines on angiogenesis bioassays to serve for current and future reference.

Bispectrality and Time-Band-Limiting: Matrix valued polynomials Grünbaum, Alberto; Pacharoni, Maria Ines; Zurrián, Ignacio Nahuel The subject of time-band-limiting, originating in signal processing, is dominated by the miracle that a naturallyappearing integral operator admits a commuting dierential one, allowing for a numerically ecient way to compute itseigenfunctions. Bispectrality is an eort to dig into the reasons behind this miracle and goes back to joint work with H.Duistermaat. This search has revealed unexpected connections with several parts of mathematics, including integrablesystems. Here we consider a matrix-valued version of bispectrality and give a general condition under which we candisplay a constructive and simple way to obtain the commuting dierential operator. Furthermore, we build an operatorthat commutes with both the time-limiting operator and the band-limiting operators.

Completeness of the Bethe Ansatz for an Open q -Boson System with Integrable Boundary Interactions van Diejen, Jan Felipe; Emsiz, Erdal; Zurrián, Ignacio Nahuel We employ a discrete integral-reflection representation of the double affine Hecke algebra of type C∨C at the critical level q = 1 , to endow the open finite q-boson system with integrable boundary interactions at the lattice ends. It is shown that the Bethe Ansatz entails a complete basis of eigenfunctions for the commuting quantum integrals in terms of Macdonald’s three-parameter hyperoctahedral Hall–Littlewood polynomials.

Una mirada comparativa sobre la edición y circulación de historietas en España y Argentina en el Siglo XXI Gago, Sebastian Horacio En las últimas décadas, la historieta ha ganado reconocimiento entre el público general, instituciones del Estado, medios de comunicación masiva, el ámbito académico y el campo cultural. Este cambio de estatus puede ser entendido en correlación con un proceso de renovación económica y cultural. En España y Argentina, la tradicional industria editorial de historietas desapareció en los años noventa del siglo XX. En el país europeo, el medio se ha tornado una renovada industria que experimentó un crecimiento creativo y una progresiva consolidación editorial. En la nación sudamericana, han proliferado pequeños emprendimientos editoriales autogestivos que revitalizaron un mercado drásticamente reducido desde la crisis de 2001. Este texto busca examinar las condiciones que produjeron cambios estructurales en la circulación de historietas en España y la Argentina durante las últimas dos décadas. Nuestra hipótesis es que los usos sociales, las prácticas lectoras, los mecanismos de legitimación y las estrategias editoriales son mediaciones culturales entre las historietas y sus lectores. Sin esas mediaciones no puede entenderse que el medio actualmente sea considerado un producto cultural con una legitimidad y visibilidad que no había tenido en el siglo pasado, cuando aún revestía un carácter masivo y popular.; Currently comics have gained recognition within readers, public institutions, journalism and intellectual and cultural fields. This change can be understood in correlation with a process of social and economic renewal. In box the Spanish and Argentine cases, the traditional comic publishing industry disappeared in the nineties. In the European country, comics became a renewed industry that is facing an increase in sales and a progressive consolidation within the publishing world. In the South American country, following the Argentinean Crisis of December 2001, small self-managed publishing enterprises have proliferated and they revitalized a small market. The objective of this research is to examine the social conditions that produced structural changes in the circulation of comics in Spain and Argentina over the last two decades. Our hypothesis is that social uses, reading practices, mechanisms of legitimacy and publishing strategies are cultural mediations between comics and readers. This reorganization in the forms of production and circulation of symbolic goods changed its way of insertion in social life. Therefore, cultural mediations made the Spanish and Argentine comic to be considered as a cultural product with a kind of legitimacy and visibility that it did not have before.

Trabajo no remunerado y uso del tiempo en la Argentina de principios del siglo XXI Delfino, María Andrea; Herzfeld, Claudia Lorena; Arrillaga, Hugo Este artículo presenta y analiza las tendencias centrales surgidas de la ?Encuesta sobre trabajo no remunerado y uso del tiempo?, realizada por primera vez en Argentina en el último trimestre de 2013, como módulo de la Encuesta Anual de Hogares Urbanos. La encuesta recogió respuestas de 65.000 personas mayores de 18 años en localidades de dos mil o más habitantes en todo el país; en este sentido es representativa de 80% del territorio argentino. Las tendencias que se analizan corresponden a los datos relativos a dos tipos de trabajo no remune-rado: el doméstico (quehaceres del hogar) y los cuidados a miembros del hogar (actividades de cuidado de ni-ños, enfermos o adultos mayores, y actividades de apoyo escolar y/o de aprendizaje); y el trabajo voluntario, es decir, aquellas actividades no remuneradas hechas libremente para el beneficio de personas ajenas a la familia.

Circadian rhythms of factors involved in luteal regression are modified in p55 tumour necrosis factor receptor (TNFRp55)-deficient mice de la Vega, Magali del Carmen; Delsouc, María Belén; Ponce, Ivana Tamara; Ragusa, Juan Antonio Vicente; Vallcaneras, Sandra; Anzulovich Miranda, Ana Cecilia; Casais, Marilina The rhythm of factors involved in luteal regression is crucial in determining the physiological duration of the oestrous cycle. Given the role of tumour necrosis factor (TNF)-α in luteal function and circadian regulation and that most of the effects of TNF-α are mediated by p55 TNF receptor (TNFRp55), the aims of the present study were to analyse the following during the luteal regression phase in the ovary of mice: (1) whether the pattern of expression of progesterone (P4) and the enzymes involved in the synthesis and degradation of P4 is circadian and endogenous (the rhythm persists in constant conditions, (i.e., constant darkness) with a period of about 24 hours); (2) circadian oscillations in clock gene expression; (3) whether there are daily variations in the expression of key genes involved in apoptosis and antioxidant mechanisms; and (4) the consequences of TNFRp55 deficiency. P4 was found to oscillate circadianally following endogenous rhythms of clock factors. Of note, TNFRp55 deficiency modified the circadian oscillation in P4 concentrations and its enzymes involved in the synthesis and degradation of P4, probably as a consequence of changes in the circadian oscillations of brain and muscle ARNT-Like protein 1 (Bmal1) and Cryptochrome 1 (Cry1). Furthermore, TNFRp55 deficiency modified the circadian rhythms of apoptosis genes, as well as antioxidant enzymes and peroxidation levels in the ovary in dioestrus. The findings of the present study strengthen the hypothesis that dysregulation of TNF-α signalling may be a potential cause for altered circadian and menstrual cycling in some gynaecological diseases.

Spectrum of J-frame operators Giribet, Juan Ignacio; Langer, Matthias; Leben, Leslie; Maestripieri, Alejandra Laura; Martinez Peria, Francisco Dardo; Trunk, Carsten Joachim A J-frame is a frame F for a Krein space (H, [⋯, ⋯]) which is compatible with the indefinite inner product [⋯, ⋯] in the sense that it induces an indefinite reconstruction formula that resembles those produced by orthonormal bases in H. With every J-frame the so-called J-frame operator is associated, which is a self-adjoint operator in the Krein space H. The J-frame operator plays an essential role in the indefinite reconstruction formula. In this paper we characterize the class of J-frame operators in a Krein space by a 2 × 2 block operator representation. The J-frame bounds of F are then recovered as the suprema and infima of the numerical ranges of some uniformly positive operators which are build from the entries of the 2 × 2 block representation. Moreover, this 2 × 2 block representation is utilized to obtain enclosures for the spectrum of J-frame operators, which finally leads to the construction of a square root. This square root allows a complete description of all J-frames associated with a given J-frame operator.

Evaluation of Water Activity in H2O-PEG400-PEG6000 Solutions between 318.15 and 348.15 K Paulazzo, Micaela G.; Passamonti, Francisco Javier The vapor pressure of H2O(1)-polyethylene glycol 400(2)-polyethylene glycol 6000(3) solutions was evaluated experimentally in a temperature range between 318.15 and 348.15 K and in a broad range of concentrations. The dependence of the solvent activity on composition was evaluated and correlated by means of a polynomial expression, in terms of concentrations, volumetric and mass fractions, and temperature, obtaining in all cases standard deviations less than 0.0086 and 0.0106 for a1(φ2,φ3,T) and a1(w2,w3,T), respectively.

Virtual prototype of a low-cost vacuum baffle based on thermoelectric cooling Conde Garrido, Juan Manuel; Silveyra, Josefina María Contaminants can enter vacuum systems from two main sources: backstreaming of oil vapors from the diffusion and mechanical pumps, and vapors generated as byproducts in the process chamber. Both sources can be hindered by using an appropriate baffle. We developed a virtual prototype of a low-cost baffle for vacuum systems that is cooled down with thermoelectric coolers (TECs). Compared to compressor cooling systems, TECs have useful advantages for this application: they are compact, silent, vibration-free, almost maintenance-free, inexpensive, widely commercially available, and capable of providing a precise temperature control. The baffle is partly built inside a tee vacuum fitting. A refrigerated cooper helix provides the trapping surfaces for contaminants flowing between the process chamber and the vacuum pumps. The cost of the baffle is below USD 250. The proof-of-concept model, implemented by the finite element method, showed that, when using TEC1-12706 modules, the helix can reach temperatures as low as −50 °C. According to our analysis, this temperature is more than enough for trapping the contaminants described above.

The peri-urban interface: hydrological effects of anthropogenic pressure Delgado, María Isabel; Carol, Eleonora Silvina; Casco, Maria Adela; Mac Donagh, María Elicia The province of Buenos Aires (Argentina) is one of the main productive areas of the country. In the These days of the province landscape is shaped by a mosaic of rural and urban sectors; here is placed the Cinturón Hortícola Platens integrated by a set of watersheds with different level of anthropogenic modification. The aim of this work was to evaluate how land use covers change process, derived from anthropogenic pressure, affects the hydrological and environmental characteristics of flat land watersheds; for this purpose, it was chosen as case study the peri-urban watershed of El Pesaro Creek, located in Argentina s Pampas region. This watershed has historically presented the least anthropogenic impact, but nowadays shows evident productive and real estate expansion. Land use change was evaluated with satellite images; current land use mainly includes urbanization, cattle raising and intensive agriculture. Surface water chemistry was determined by sampling different sections of the creek, groundwater sampling was based on groundwater monitoring wells distributed along the watershed. Physical-chemical water parameters were determined in situ, major ions were determined in laboratory under standardized methods. Results were compared with hydro chemical previous studies (when the whole watershed was characterized as rural, with extensive livestock farming), allowing to conclude that the most important quantifiable modifications from an ecohydrological perspective are being registered in the upper watershed. In this area is where land use is turning to intensive horticulture (greenhouses), with no planning and minimal precautions about its possible impact on natural resources. Results obtained constitutes a valuable tool for the generation of management strategies not only for this particular watershed, but could also be extrapolated to areas with similar territorial dynamics.

“discamus naturales incurvationes rectificare”: De ludo globi I. Un diálogo entre el hombre y la naturaleza; “discamus naturales incurvationes rectificare”: De ludo globi I. A dialog between man and nature Rusconi, Maria Cecilia Como lo indica su título, el diálogo De ludo globi está construido en torno a un juego. Este juego consta de dos elementos: una bocha de madera levemente ahuecada y una superficie sobre la que están dibujados diez círculos concéntricos. El significado de cada uno de los círculos es detallado en el Libro II. Por su parte, el Libro I se ocupa de la forma de la bocha y su movimiento. El desafío al que se enfrenta el presente trabajo reside en encontrar una unidad sistemática, que sirva de hilo conductor del diálogo De ludo globi, en el marco del Libro I. Esta sistematización del texto deberá mostrar que el diálogo tiene como trasfondo otra dimensión dialógica, que muestra al texto como un diálogo del individuo con la naturaleza. Con esta intención, el presente trabajo está articulado en tres partes. En primer lugar (1) me concentraré en la bocha y su movimiento. En segundo lugar (2) abordaré el planteo cusano del alma y el cuerpo. Éste deberá dirigirnos, por último, a (3) una distinción entre la libertad y la naturaleza.; As its title indicates, Cusanus’ dialogue De ludo globi is built around a game. This game is composed of two elements: a slightly concave wooden ball and a surface on which nine concentric circles are drawn. The meaning of each circle is detailed in Book II of De ludo globi. For its part, Book I deals with the ball and its movement. My paper seeks to find a systematic unity that can become a guiding interpretive framework for the dialogue, in the context of Book I. This systematic unity must also show that the work incorporates in the background another, dialogical dimension, in which we can read De ludo globi as a dialogue between man and nature. With this in mind, I’ve divided the paper into three parts. First, (1) I will focus on the ball itself and its movement. Secondly, (2) I will present Cusanus’ approach to soul and body. This approach will then lead us to (3) a distinction between freedom and nature.