Ciencia y Tecnología
Antitumoral, Antihypertensive, Antimicrobial, and Antioxidant Effects of an Octanuclear Copper(II)-Telmisartan Complex with an Hydrophobic Nanometer Hole
Islas, María Soledad; Martínez Medina, Juan José; López Tévez, Libertad Leonor; Rojo, Teófilo; Lezama, Luis; Griera Merino, Mercedes; Calleros, Laura; Cortés, María Alicia; Rodriguez Puyol, Manuel; Echeverría, Gustavo Alberto; Piro, Oscar Enrique; Ferrer, Evelina Gloria; Williams, Patricia Ana María
A new Cu(II) complex with the antihypertensive drug telmisartan, [Cu8Tlm16].24H2O (CuTlm), was synthesized and characterized by elemental analysis and electronic, FTIR, Raman and EPR spectroscopy. The crystal structure (at 120 K) was solved by X-ray diffraction methods. The octanuclear complex is a hydrate of but otherwise isostructural to the previously reported [Cu8Tlm16] complex. [Cu8Tlm16].24H2O crystallizes in the tetragonal P4/ncc space group with a=b=47.335(1), c=30.894(3) Å, Z=4 molecules per unit cell giving a macro-cyclic ring with a double helical structure. The Cu(II) ions are in a distorted bi-pyramidal environment with a somewhat twisted square basis, cis-coordinated at their core N2O2 basis to two carboxylate oxygen and to two terminal benzimidazole nitrogen atoms. Cu8Tlm16 has a toroidal-like shape with a hydrophobic nanometer hole and their crystal packing defines nano-channels that extend along the crystal c-axis. Several biological activities of the complex and the parent ligand were examined in vitro. The antioxidant measurements indicate that the complex behaves as a superoxide dismutase mimics with improved superoxide scavenger power as compared with native sartan. The capacity of telmisartan and its copper complex to expand human mesangial cells (previously contracted by angiotensin II treatment) is similar to each other. The antihypertensive effect of the compounds is attributed to the strongest binding affinity to angiotensin II type 1 receptor and not to the antioxidant effects. The cytotoxic activity of the complex and that of its components was determined against lung cancer cell line A549 and three prostate cancer cell lines (LNCaP, PC-3 and DU 145). The complex displays some inhibitory effect on the A549 line and a high viability decrease on the LNCaP (androgen-sensitive) line. From flow cytometric analysis it was established an apoptotic mechanism for the latter cell line. Telmisartan and CuTlm show antibacterial and antifungal activities in various strains and CuTlm displays improved activity against the Stafilococcus aureus strain as compared with unbounded copper(II).
BIOFRAG: A new database for analysing BIOdiversity responses to forest FRAGmentation
BIOFRAG: A new database for analysing BIOdiversity responses to forest FRAGmentation
Pfeifer, Marion; Lefebvre, Veronique; Gardner, Toby A.; Arroyo Rodríguez, Víctor; Baeten, Lander; Banks Leite, Cristina; Barlow, Jos; Betts, Matthew G.; Brunet, Joerg; Cerezo Blandón, Alexis Mauricio; Cisneros, Laura M.; Collard, Stuart; D´Cruze, Neil; Da Silva Motta, Catarina; Duguay, Stephanie; Eggermont, Hilde; Eigenbrod, Félix; Hadley, Adam S.; Hanson, Thor R.; Hawes, Joseph E.; Heartsill Scalley, Tamara; Klingbeil, Brian T.; Kolb, Annette; Kormann, Urs; Kumar, Sunil; Lachat, Thibault; Lakeman Fraser, Poppy; Lantschner, María Victoria; Laurance, William F.; Leal, Inara R.; Lens, Luc; Marsh, Charles J.; Medina Rangel, Guido F.; Melles, Stephanie; Mezger, Dirk; Oldekop, Johan A.; Overal , Williams L.; Owen, Charlotte; Peres, Carlos A.; Phalan, Ben; Pidgeon, Anna Michle; Pilia, Oriana; Possingham, Hugh P.; Possingham, Max L.; Raheem, Dinarzarde C.; Ribeiro, Danilo B.; Ribeiro Neto, Jose D.; Robinson, Douglas W.; Robinson, Richard; Rytwinski, Trina; Scherber, Christoph; Slade, Eleanor M.; Somarriba, Eduardo; Stouffer, Philip C.; Struebig, Matthew J.; Tylianakis, Jason M.; Teja, Tscharntke; Tyre, Andrew J.; Urbina Cardona, Jose N.; Vasconcelos, Heraldo L.; Wearn, Oliver; Wells, Konstans; Willig, Michael R.; Wood, Eric; Young, Richard P.; Bradley, Andrew V.; Ewers, Robert M.
Habitat fragmentation studies are producing inconsistent and complex results across which it is nearly impossible to synthesise. Consistent analytical techniques can be applied to primary datasets, if stored in a flexible database that allows simple data retrieval for subsequent analyses. Method: We developed a relational database linking data collected in the field to taxonomic nomenclature, spatial and temporal plot attributes and further environmental variables (e.g. information on biogeographic region. Typical field assessments include measures of biological variables (e.g. presence, abundance, ground cover) of one species or a set of species linked to a set of plots in fragments of a forested landscape. Conclusion: The database currently holds records of 5792 unique species sampled in 52 landscapes in six of eight biogeographic regions: mammals 173, birds 1101, herpetofauna 284, insects 2317, other arthropods: 48, plants 1804, snails 65. Most species are found in one or two landscapes, but some are found in four. Using the huge amount of primary data on biodiversity response to fragmentation becomes increasingly important as anthropogenic pressures from high population growth and land demands are increasing. This database can be queried to extract data for subsequent analyses of the biological response to forest fragmentation with new metrics that can integrate across the components of fragmented landscapes. Meta-analyses of findings based on consistent methods and metrics will be able to generalise over studies allowing inter-comparisons for unified answers. The database can thus help researchers in providing findings for analyses of trade-offs between land use benefits and impacts on biodiversity and to track performance of management for biodiversity conservation in human-modified landscapes.
Violencia y materialidad de la ficción. (Sobre la recepción de Django Unchained)
Violencia y materialidad de la ficción. (Sobre la recepción de Django Unchained)
Pachilla, Pablo Nicolás
En este artículo se discuten los conceptos de "estetización de la violencia" y "glorificación de la violencia" a propósito de Django Unchained de Quentin Tarantino. Se apunta al carácter metaficcional de los films de dicho director, en los cuales el espectador se ve confrontado a sus propias fantasías sádicas, y se procura desligar la violencia presente en ellas de la noción de justicia, contraponiéndola de este modo a la muchedumbre de películas en las que el protagonista "apela al cielo", al decir lockeano, para hacer justicia por mano propia. Se contrastan asimismo dos tipos de violencia: aquella propia de la esclavitud, por un lado, y lo que el director llama "movie violence", por el otro.
¿Es realmente valiosa la igualdad política?
¿Es realmente valiosa la igualdad política?
Garcia Valverde, Facundo
el objetivo de este artículo es defender el valor normativo de un principio de igualdad de oportunidades para influir políticamente en contra de un principio que las distribuya de manera desigual pero beneficiando a los peor situados. Para ello, se muestra que la influencia política es un bien de un tipo especial que permite rechazar la objeción de la nivelación hacia abajo y que la igualdad política, aunque pueda ser derrotada por consideraciones epistémicas, es absolutamente necesaria para criticar aspectos inequitativos de una distribución desigual.; el objetivo de este artículo es defender el valor normativo de un principio de igualdad de oportunidades para influir políticamente en contra de un principio que las distribuya de manera desigual pero beneficiando a los peor situados. Para ello, se muestra que la influencia política es un bien de un tipo especial que permite rechazar la objeción de la nivelación hacia abajo y que la igualdad política, aunque pueda ser derrotada por consideraciones epistémicas, es absolutamente necesaria para criticar aspectos inequitativos de una distribución desigual.
Las Dimensiones Morales de la Vida Colectiva: Exploraciones desde los Estudios Sociales de las Moralidades
Las Dimensiones Morales de la Vida Colectiva: Exploraciones desde los Estudios Sociales de las Moralidades
Noel, Gabriel David
Ante un panorama en el cual la tematización de las dimensiones morales de la vida social ocupa un lugar quizás no central, pero si creciente y notorio en las agendas de la sociología y la antropología, el presente dossier se presenta como una invitación teórica y metodológica, pero sobre todo heurística, que procura mostrar a partir de experiencias concretas de investigación en ciencias sociales la productividad de interrogar y construir nuestros objetos desde un punto de vista que se sitúa en el terreno de las indagaciones sobre el lugar de la moral y lo moral en la vida social. El objeto de esta compilación no apunta específicamente a tematizar la moral como objeto de las ciencias sociales sino a mostrar a partir de trabajos concretos surgidos de experiencias de investigación qué es lo que permite y habilita el movilizar la moral como recurso teórico, como herramienta metodológica o como perspectiva de análisis.
Los docentes universitarios y su concepción sobre el aprendizaje, la autorregulación y la personalización educativa: Un análisis desde la teoría fundamentada
Los docentes universitarios y su concepción sobre el aprendizaje, la autorregulación y la personalización educativa: Un análisis desde la teoría fundamentada
Daura, Florencia Teresita
Se presentan los resultados de una investigación en la que se efectuaron entrevistas semiestructuradas en profundidad a los docentes responsables de asignaturas del Ciclo Clínico de la carrera de Medicina que se dicta en una universidad privada y otra estatal. Los datos recogidos se analizaron a partir del modelo ofrecido por la teoría fundamentada (STRAUSS & CORBIN 1998) con el objeto de elaborar una interpretación sobre cuál es la concepción que los profesores poseen sobre tres conceptos que se consideran centrales en el proceso educativo: el aprendizaje, la capacidad autorreguladora y la personalización.
Palliative care staff perspectives: The challenges of end-of-life care on their professional practices and everyday lives
Palliative care staff perspectives: The challenges of end-of-life care on their professional practices and everyday lives
Luxardo, Natalia; Vindrola Padros, Cecilia; Tripodoro, Vilma
This article has 3 goals: To describe the attitudes and experiences of staff on end-of-life care treatment of dying persons, to examine how the staff view their terminally ill patients, and to gather professionals' opinions on how their experiences impact their daily lives. It is a qualitative research inquiry based on a constructivist-grounded theory design. The study subjects were professionals who were part of palliative care services in Buenos Aires city during 2012. A purposive sample of 30 personnel answered an open-ended questionnaire assessing attitudes and perceptions concerning end-of-life. The results showed the following: (a) "Good" deaths were considered those in which physical symptoms were dealt with, where the patient was surrounded or on good terms with family members, and where they were at peace with themselves, any unfinished business, or God. "Bad" deaths were believed to be those where the patient was physically uncomfortable, were within a conspiracy-silence atmosphere, and died alone. (b) The factors in common that staff members identified regarding deaths were the need for spiritual comfort, peace, and acceptance and the need for attaining a deep connection with others. (c) The unexpected issues identified among end-of-life trajectories were the varying attitudes that patients had regarding death. (d) The personal life of the staff was affected by being in charge of end-of-life care decision making.
Exploring trends in labor informality in Latin America, 1990-2010
Exploring trends in labor informality in Latin America, 1990-2010
Tornarolli, Leopoldo Horacio; Battistón, Diego Ezequiel; Gasparini, Leonardo Carlos; Gluzmann, Pablo Alfredo
Labor informality is a pervasive characteristic of the labor markets in Latin America, and a central issue in the public policy debate. This paper discusses the concept of labor informality and implements alternative definitions using microdata from around 300 national household surveys in all Latin American countries. The analysis covers two decades: while labor informality, defined as lack of social protection related to employment, remained with few changes in the 1990s, there is a discernible downward pattern during the 2000s in most countries. These movements reveal a counter-cyclical behavior of labor informality, that may be linked to segmentation in the labor market.
On the use of the double floating probe method to infer the difference between the electron and the heavy particles temperatures in an atmospheric pressure, vortex?stabilized nitrogen plasma jet
On the use of the double floating probe method to infer the difference between the electron and the heavy particles temperatures in an atmospheric pressure, vortex?stabilized nitrogen plasma jet
Prevosto, Leandro; Kelly, Hector Juan; Mancinelli, Beatriz Rosa
Sweeping double probe measurements in an atmospheric pressure direct current vortex-stabilized plasma jet are reported (plasma conditions: 100 A discharge current, N2 gas flow rate of 25 Nl/min, thoriated tungsten rod-type cathode, copper anode with 5 mm inner diameter). The interpretation of the double probe characteristic was based on a generalization of the standard double floating probe
formulae for non-uniform plasmas coupled to a non-equilibrium plasma composition model. Perturbations caused by the current to the probe together with collisional and thermal processes inside the probe perturbed region were taken into account. Radial values of the average electron and heavy particle temperatures as well as the electron density were obtained. The calculation of the temperature values did not require any specific assumption about a temperature relationship between different particle species. An electron temperature of 10 900 ± 900 K, a heavy particle temperature of 9300 ± 900 K, and an electron density of about 3.5 × 1022 m−3 were found at the jet centre at 3.5 mm downstream from the torch exit. Large deviations from kinetic equilibrium were found toward the outer border of the plasma jet. These results showed good agreement with those previously reported
by the authors by using a single probe technique. The calculations have shown that this method is particularly useful for studying spraying-type plasma torches perated at power levels of about 15 kW
"Escuchar el cuerpo y creer en eso": Exploraciones en torno a la noción de registro de sí en el marco de las medicinas alternativas (Buenos Aires, Argentina)
"Escuchar el cuerpo y creer en eso": Exploraciones en torno a la noción de registro de sí en el marco de las medicinas alternativas (Buenos Aires, Argentina); Listen to your body and believe in that: Explorations of the notion of self-reflection in the context of alternative medicine (Buenos Aires, Argentina); “Escutar o corpo e acreditar nisso”: Explorações em torno à noção de autorreflexão no marco das medicinas alternativas (Buenos Aires, Argentina)
Bordes, Mariana Argentina
El artículo tiene como objetivo explorar un aspecto de la lógica del cuidado de la salud que se delinea en el universo de las medicinas alternativas, no-convencionales, o complementarias y alternativas, como las denomina la Organización Mundial de la Salud (OMS, 2002): el que pondera el registro de sí como una de las dimensiones de la eficacia terapéutica en sentido amplio. Cabe destacar que este trabajo se desprende de una investigación de tesis doctoral centrada en analizar la construcción de significados terapéuticos en el marco de una medicina alternativa en particular (la reflexología), la cual fue llevada adelante desde una perspectiva sociológica cualitativa.; The article aims to analyze one aspect of the logic of health care that is outlined in the universe of alternative, non-conventional, or complementary and alternative medicine, as the World Health Organization denominates them (WHO, 2002); we refer to the notion of selfreflection and self-knowledge as one of the dimensions of the therapeutic efficacy in a broad sense. It is worth noting that that this work is based on the research for a doctoral dissertation focused on analyzing the construction of therapeutic meanings within the framework of a particular form of alternative medicine (reflexology), which was carried out from a qualitative sociological perspective.; O artigo tem como objetivo explorar um aspecto da lógica do cuidado da saúde que se delineia no universo das medicinas alternativas, não convencionais, ou complementárias e alternativas, como denomina a Organização Mundial de Saúde (OMS, 2002): o que pondera a autorreflexão como uma das dimensões da eficácia terapêutica em sentido amplo. É importante destacar que este trabalho deriva-se uma pesquisa de tese doutoral centrada em analisar a construção de significados terapêuticos no marco de uma medicina alternativa em particular (a reflexologia), a qual foi levada adiante desde uma perspectiva sociológica qualitativa.
Morphometry and Relative Growth of Populations of Tanais dulongii (Audoin, 1826) (Tanaidacea: Tanaidae) in Pristine and Impacted Marine Environments of the Southwestern Atlantic
Morphometry and Relative Growth of Populations of Tanais dulongii (Audoin, 1826) (Tanaidacea: Tanaidae) in Pristine and Impacted Marine Environments of the Southwestern Atlantic
Rumbold, Carlos Enrique; Obenat, Sandra Mabel; Spivak, Eduardo Daniel
Life history strategies are closely related to environmental conditions and biotic and abiotic factors play a major role conditioning several traits as growth rates, sexual maturity, size and morphometric differences. We compare body dimensions, relative growth patterns, and size of sexual differentiation between populations of Tanais dulongii (Audoin, 1826) that live in two contrasting habitats in order to determine if they differ in life history traits. Some 900 individuals were collected (150 males, 150 females and 150 juveniles from each site) in a rocky shore with a lower anthropic impact (La Estafeta) and a polluted area (Mar del Plata Harbor) and thirteen body dimensions between sexes and environments were compared. Relative growth rates were determined establishing the relationship between total length (TL) and the rest of body dimensions with reduced major axis method (RMA). Regression slopes were employed to test the degree of isometry or allometry. MDS and SIMPER analyses were used to plot and identify morphometric differences between sexes and populations. TL and the rest of body dimensions were longer in La Estafeta than in Mar del Plata, and degree of sexual differentiation was larger in La Estafeta (ca. 3.5 mm) than in Mar del Plata (1.75 mm). RMA showed differences among sites: in Mar del Plata growth of most dimensions was positively allometric in adults, but in La Estafeta half of the measured dimensions had positive allometric growth for both sexes and half had isometric or negative allometric growth. Juveniles of both sites showed a positively allometric growth. MDS established a clear separation between sites and sexes. SIMPER showed that TL, cheliped length, cheliped width, and antennule peduncle length contributed most to differences between sexes, and TL (mainly) and the rest of variables (in minor degree) in the dissimilarities between sites. We believe that the differences observed between populations of T. dulongii are due to phenotypic plasticity in this species in response to environmental differences.
Inflammation in response to phytohemagglutinin injection in the Talas tuco-tuco (Ctenomys talarum): implications for the estimation of immunocompetence in natural populations of wild rodents
Inflammation in response to phytohemagglutinin injection in the Talas tuco-tuco (Ctenomys talarum): implications for the estimation of immunocompetence in natural populations of wild rodents
Merlo, Julieta; Cutrera, Ana Paula; Zenuto, Roxana Rita
The immunological variation in wild populations and its relation to life-history traits has recently become a central topic in the field of evolutionary biology, considering the critical contribution of immunity to an individual’s fitness. A common technique used by ecologists to estimate immunocompetence in wild populations is the phytohemagglutinin (PHA) – skin test. In this test, the degree of local swelling triggered by PHA is usually considered an estimate of T-lymphocyte activity, although there is an ongoing debate regarding this interpretation. Here, we coupled the PHA–skin test with a histological analysis to examine the temporal development of the cell-mediated response in the subterranean rodent Talas tuco-tuco (Ctenomys talarum Thomas, 1898). The inflammation response involved lymphocytes, neutrophils, eosinophils, and macrophages at the site of injection, achieving an increase of total leukocytes from 12 to 48 h after injection. However, the abundance of any of the leukocytes observed did not correlate with the degree of swelling at any time studied, suggesting that caution should be taken when interpreting the results of the PHA-induced swelling response. Particularly, the magnitude of macroscopic swelling should not be considered a priori as indicative of T-lymphocyte activity in wild-caught rodents. Our results highlight the importance of avoiding oversimplified approaches to measuring immunocompetence.
Signature of Nonadiabatic Coupling in Excited-State Vibrational Modes
Signature of Nonadiabatic Coupling in Excited-State Vibrational Modes
Soler Bastida, Miguel Ángel; Nelson, Tammie; Roitberg, Adrián; Tretiak, Sergei; Fernández Alberti, Sebastián
Using analytical excited-state gradients, vibrational normal modes have been calculated at the minimum of the electronic excited-state potential energy surfaces for a set of extended conjugated molecules with different coupling between them. Molecular model systems composed of units of polyphenylene ethynylene (PPE), polyphenylenevinylene (PPV), and naphthacene/pentacene (NP) have been considered. In all cases except the NP model, the influence of the nonadiabatic coupling on the excited-state equilibrium normal modes is revealed as a unique highest frequency adiabatic vibrational mode that overlaps with the coupling vector. This feature is removed by using a locally diabatic representation in which the effect of NA interaction is removed. Comparison of the original adiabatic modes with a set of vibrational modes computed in the locally diabatic representation demonstrates that the effect of nonadiabaticity is confined to only a few modes. This suggests that the nonadiabatic character of a molecular system may be detected spectroscopically by identifying these unique state-specific high frequency vibrational modes.
Continuous phase estimation from noisy fringe patterns based on the implicit smoothing splines
Continuous phase estimation from noisy fringe patterns based on the implicit smoothing splines
Wielgus, Maciek; Patorski, Krzysztof; Etchepareborda, Pablo Gonzalo; Federico, Roque Alejandro
We introduce the algorithm for the direct phase estimation from the single noisy interferometric pattern. The method, named implicit smoothing spline (ISS), can be regarded as a formal generalization of the smoothing spline interpolation for the case when the interpolated data is given implicitly. We derive the necessary equations, discuss the properties of the method and address its application for the direct estimation of the continuous phase in both classical interferometry and digital speckle pattern interferometry (DSPI). The numerical illustrations of the algorithm performance are provided to corroborate the high quality of the results.
Deconvolution of isotope signals from bundles of multiple hairs
Deconvolution of isotope signals from bundles of multiple hairs
Remien, Christopher H.; Adler, Frederick R.; Chesson, Lesley A.; Valenzuela, Luciano Oscar; Ehleringer, James R.; Cerling, Thure E.
Segmental analysis of hair has been used in diverse fields ranging from forensics to ecology to measure the concentration of substances such as drugs and isotopes. Multiple hairs are typically combined into a bundle for segmental analysis to obtain a high-resolution series of measurements. Individual hair strands cycle through multiple phases of growth and grow at different rates when in the growth phase. Variation in growth of hair strands in a bundle can cause misalignment of substance concentration between hairs, attenuating the primary body signal. We developed a mathematical model based on the known physiology of hair growth to describe the signal averaging caused by bundling multiple hairs for segmental analysis. The model was used to form an inverse method to estimate the primary body signal from measurements of a hair bundle. The inverse method was applied to a previously described stable oxygen isotope chronology from the hair of a murder victim and provides a refined interpretation of the data. Aspects of the reconstruction were confirmed when the victim was later identified.
Celia Lapalma de Emery y la cuestión social desde una perspectiva católica en el temprano siglo XX argentino
Celia Lapalma de Emery y la cuestión social desde una perspectiva católica en el temprano siglo XX argentino; Celia Lapalma de Emery and the Social Question from a Catholic View-point in the Early Twentieth Century Argentina
Acha, José Omar
El Estado argentino de inicios del siglo veinte se hallaba en un momento de consolidación y extensión en la sociedad en proceso de cambio. Uno de sus aspectos más relevantes consistió en el desarrollo de instrumentos y discursos para responder a la “cuestión social”. En este artículo se reconstruye la acción y opiniones de una inspectora del Departamento Nacional del Trabajo especializada en el trabajo femenino y activista católica, Celia Lapalma de Emery. Se muestra con ello las diferentes opciones culturales respecto del trabajo, y particularmente del trabajo femenino, en el seno de las instituciones estatales.; In the beginning of the XXth century the Argentinean State was consolidating and spreading its power on the changing society. One of the main aspects of its developments concerned the building of tools to answer to the so called “social question”. This article deals with the action and beliefs of an inspector of the National Labor Department, Celia Lapalma de Emery, who was specialized on feminine labor. In doing so it is demonstrated the different cultural perspectives regarding labor, particularly the feminine one, in the core of the state institutions.
Continuing impacts on red deer from a volcanic eruption in 2011
Continuing impacts on red deer from a volcanic eruption in 2011
Fluck, Werner Thomas
In June of 2011, the Puyehue–Cordon Caulle volcanic eruption deposited large amounts of ashes in Chile and Argentina. Although ashes were initially considered innoxious based on water leachates, we found clinical cases of fluoride intoxication in red deer (Cervus elaphus) and domestic herbivores in Argentina. The diagnosis was corroborated by high bone fluoride concentrations. The dynamics of temporal accumulation of fluoride suggested an average increase of 1,000 ppm per year of fluoride in the bone. However, a few deer had fluoride levels, suggesting an accumulation rate of about 3,700 ppm per year. Via recent sampling of deer, we now confirm that bone levels have reached up to 10,396 ppm of fluoride after about 28 months of exposure. Tephra across various sites averaged 548 ppm of fluoride, and due to dry conditions and eolic redeposition of ashes particularly east of the continental divide, clinical fluorosis is expected to continue to intensify. The described impact will reverberate through several aspects of the ecology of the deer, including effects on population dynamics, morbidity, predation susceptibility, as well as other components of the ecosystem, including other herbivores, scavengers, and plant communities.
Water and Membrane Dynamics in Suspensions of Lipid Vesicles Functionalized with Poly(ethylene glycol)s
Water and Membrane Dynamics in Suspensions of Lipid Vesicles Functionalized with Poly(ethylene glycol)s
Clop, Eduardo Matias; Chattah, Ana Karina; Perillo, Maria Angelica
The present work was aimed at studying the molecular dynamics at different levels of model membranes having a simulated glycoclix, with focus on the molecular crowding conditions at the lipid–water interfacial region. Thus, binary mixtures of dipalmitoylphosphatidylcholine (dpPC) and a poly(ethylene glycol) (PEGn) derivative of dipalmitoylphosphatidylethanolamine (PE) (where n = 350, 1000, and 5000, respectively, refer to PEG molecular masses) were submitted to 1H spin–lattice relaxation time (T1) and 31P NMR spectra analysis. 1H NMR relaxation times revealed two contributing components in each proton system (PEG, phospholipids, and water), for all the mixtures studied, exhibiting values of T1 with very different orders of magnitude. This allowed identifying confined and bulk water populations as well as PEG moieties becoming more disordered and independent from the phospholipid moiety as n increased. 31P spectra showed a typical broad bilayer signal for n = 350 and 1000, and an isotropic signal characteristic of micelles for n = 5000. Surface pressure (π)–molecular area isotherms and compressional modulus measurements provided further structural information. Moreover, epifluorescence microscopy data from monolayers at π ∼ 30 mN/m, the expected equilibrium π in lipid bilayers, allowed us to postulate that both 1H populations resolved through NMR in phospholipids and lipopolymers corresponded to different phase domains.
Elimination for generic sparse polynomial systems
Elimination for generic sparse polynomial systems
Herrero, Maria Isabel; Jeronimo, Gabriela Tali; Sabia, Juan Vicente Rafael
We present a new probabilistic symbolic algorithm that, given a variety defined in an n-dimensional affine space by a generic sparse system with fixed supports, computes the Zariski closure of its projection to an ℓ-dimensional coordinate affine space with ℓ
Potencialidad hídrica de la región santafesina: el acuífero guaraní en el territorio provincial
Potencialidad hídrica de la región santafesina: el acuífero guaraní en el territorio provincial
Méndez Zacarías, Jovita Soledad; Zimmermann, Erik Daniel
En este trabajo se analiza la problemática del acceso al agua en localidades de la provincia de Santa Fe, revisando el historial del servicio de agua potable en la provincia en los últimos 30 años. El mismo está enmarcado por una carencia de políticas adecuadas donde se aborde de manera integral las problemáticas asociadas con el agua ( control de crecidas, saneamiento y provisión de agua potable). Se analiza la oferta hídrica tanto en lo referente a recursos superficiales como subterráneos, poniendo énfasis en las últimas investigaciones sobre la presencia del acuífero Guaraní en el territorio provincial. A excepción de las localidades que se abastecen del Río Paraná o algunos de sus brazos, el resto de las localidades se abastecen de aguas subterráneas (el 96% del total), y en general, el recurso no es apropiado para consumo humano y requiere costosos de tratamientos de potabilización. La excelente calidad del agua y la posibilidad de captación en el lugar, hacen que el aprovechamiento potencial del Acuífero Guaraní asuma características inigualables para el abastecimiento en nuestra región. Por otra parte, considerando la demanda actual de agua para consumo, no sólo en la provincia sino también en la región se deberá reflexionar sobre los usos para balneoterapia que se le está dando actualmente, sobreexplotando el acuífero y contaminando cuerpos receptores. Resulta imperioso que la legislación respecto a los usos y la protección del Acuífero Guaraní, sea elaborada de manera consensuada por los estados soberanos que comparten el recurso sin intervención alguna de países que son ajenos a los intereses de la región.; In this paper we analyze the problem of access to drinking water in towns in the province of Santa Fe, reviewing the history of drinking water service in the province in the last 30 years. The service is framed by inappropriate policies which can holistically addresses the problems associated with water (flood control, sanitation and water supply). Water resources is analyzed in terms of both surface and groundwater resources, with emphasis on the latest research on the Guarani Aquifer presence in the province. Except for the towns that are supplied by Paraná River or some of its tributaries, the remaining localities have groundwater supply (96% of total), and in general, the resource is not suitable for human consumption and requires expensive water treatment. The excellent water quality and the ability to capture in place, make the potential use of the Guarani Aquifer assume excellent features for supply in our region. Moreover, considering the current demand for drinking water, not only in the province but also in the región, must reflect on the uses for balneotherapy currently being given. It is imperative that the legislation regarding the use and protection of the Guarani Aquifer, is made by consensus by the sovereign states sharing the resource without any intervention from countries that are outside to the interests of the region.
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